Google Git
Sign in
gnu / gcc.git / refs/heads/master / . / gcc / tree-ssa-structalias.cc
blob: 0035e50c62c73095169aa93d12f8a1f7f61a3f93 [file] [log] [blame]
/* Tree based points-to analysis
Copyright (C) 2005-2025 Free Software Foundation, Inc.
Contributed by Daniel Berlin <dberlin@dberlin.org>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
#include "alloc-pool.h"
#include "tree-pass.h"
#include "ssa.h"
#include "cgraph.h"
#include "tree-pretty-print.h"
#include "diagnostic-core.h"
#include "fold-const.h"
#include "stor-layout.h"
#include "stmt.h"
#include "gimple-iterator.h"
#include "tree-into-ssa.h"
#include "tree-dfa.h"
#include "gimple-walk.h"
#include "varasm.h"
#include "stringpool.h"
#include "attribs.h"
#include "tree-ssa.h"
#include "tree-cfg.h"
#include "gimple-range.h"
#include "ipa-modref-tree.h"
#include "ipa-modref.h"
#include "attr-fnspec.h"
#include "tree-ssa-structalias.h"
#include "pta-andersen.h"
/* The idea behind this analyzer is to generate set constraints from the
program, then solve the resulting constraints in order to generate the
points-to sets.
Set constraints are a way of modeling program analysis problems that
involve sets. They consist of an inclusion constraint language,
describing the variables (each variable is a set) and operations that
are involved on the variables, and a set of rules that derive facts
from these operations. To solve a system of set constraints, you derive
all possible facts under the rules, which gives you the correct sets
as a consequence.
See "Efficient Field-sensitive pointer analysis for C" by "David
J. Pearce and Paul H. J. Kelly and Chris Hankin", at
http://citeseer.ist.psu.edu/pearce04efficient.html
Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
of C Code in a Second" by "Nevin Heintze and Olivier Tardieu" at
http://citeseer.ist.psu.edu/heintze01ultrafast.html
There are three types of real constraint expressions, DEREF,
ADDRESSOF, and SCALAR. Each constraint expression consists
of a constraint type, a variable, and an offset.
SCALAR is a constraint expression type used to represent x, whether
it appears on the LHS or the RHS of a statement.
DEREF is a constraint expression type used to represent *x, whether
it appears on the LHS or the RHS of a statement.
ADDRESSOF is a constraint expression used to represent &x, whether
it appears on the LHS or the RHS of a statement.
Each pointer variable in the program is assigned an integer id, and
each field of a structure variable is assigned an integer id as well.
Structure variables are linked to their list of fields through a "next
field" in each variable that points to the next field in offset
order.
Each variable for a structure field has
1. "size", that tells the size in bits of that field.
2. "fullsize", that tells the size in bits of the entire structure.
3. "offset", that tells the offset in bits from the beginning of the
structure to this field.
Thus,
struct f
{
int a;
int b;
} foo;
int *bar;
looks like
foo.a -> id 1, size 32, offset 0, fullsize 64, next foo.b
foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
bar -> id 3, size 32, offset 0, fullsize 32, next NULL
In order to solve the system of set constraints, the following is
done:
1. Each constraint variable x has a solution set associated with it,
Sol(x).
2. Constraints are separated into direct, copy, and complex.
Direct constraints are ADDRESSOF constraints that require no extra
processing, such as P = &Q
Copy constraints are those of the form P = Q.
Complex constraints are all the constraints involving dereferences
and offsets (including offsetted copies).
3. All direct constraints of the form P = &Q are processed, such
that Q is added to Sol(P)
4. All complex constraints for a given constraint variable are stored in a
linked list attached to that variable's node.
5. A directed graph is built out of the copy constraints. Each
constraint variable is a node in the graph, and an edge from
Q to P is added for each copy constraint of the form P = Q
6. The graph is then walked, and solution sets are
propagated along the copy edges, such that an edge from Q to P
causes Sol(P) <- Sol(P) union Sol(Q).
7. As we visit each node, all complex constraints associated with
that node are processed by adding appropriate copy edges to the graph, or the
appropriate variables to the solution set.
8. The process of walking the graph is iterated until no solution
sets change.
Prior to walking the graph in steps 6 and 7, We perform static
cycle elimination on the constraint graph, as well
as off-line variable substitution.
TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
on and turned into anything), but isn't. You can just see what offset
inside the pointed-to struct it's going to access.
TODO: Constant bounded arrays can be handled as if they were structs of the
same number of elements.
TODO: Modeling heap and incoming pointers becomes much better if we
add fields to them as we discover them, which we could do.
TODO: We could handle unions, but to be honest, it's probably not
worth the pain or slowdown. */
/* IPA-PTA optimizations possible.
When the indirect function called is ANYTHING we can add disambiguation
based on the function signatures (or simply the parameter count which
is the varinfo size). We also do not need to consider functions that
do not have their address taken.
The is_global_var bit which marks escape points is overly conservative
in IPA mode. Split it to is_escape_point and is_global_var - only
externally visible globals are escape points in IPA mode.
There is now is_ipa_escape_point but this is only used in a few
selected places.
The way we introduce DECL_PT_UID to avoid fixing up all points-to
sets in the translation unit when we copy a DECL during inlining
pessimizes precision. The advantage is that the DECL_PT_UID keeps
compile-time and memory usage overhead low - the points-to sets
do not grow or get unshared as they would during a fixup phase.
An alternative solution is to delay IPA PTA until after all
inlining transformations have been applied.
The way we propagate clobber/use information isn't optimized.
It should use a new complex constraint that properly filters
out local variables of the callee (though that would make
the sets invalid after inlining). OTOH we might as well
admit defeat to WHOPR and simply do all the clobber/use analysis
and propagation after PTA finished but before we threw away
points-to information for memory variables. WHOPR and PTA
do not play along well anyway - the whole constraint solving
would need to be done in WPA phase and it will be very interesting
to apply the results to local SSA names during LTRANS phase.
We probably should compute a per-function unit-ESCAPE solution
propagating it simply like the clobber / uses solutions. The
solution can go alongside the non-IPA escaped solution and be
used to query which vars escape the unit through a function.
This is also required to make the escaped-HEAP trick work in IPA mode.
We never put function decls in points-to sets so we do not
keep the set of called functions for indirect calls.
And probably more. */
namespace pointer_analysis {
/* Used for points-to sets. */
bitmap_obstack pta_obstack;
/* Used for oldsolution members of variables. */
bitmap_obstack oldpta_obstack;
/* Table of variable info structures for constraint variables.
Indexed directly by variable info id. */
vec<varinfo_t> varmap;
/* List of constraints that we use to build the constraint graph from. */
vec<constraint_t> constraints;
/* Map from trees to variable infos. */
static hash_map<tree, varinfo_t> *vi_for_tree;
/* The representative variable for a variable. The points-to solution for a
var can be found in its rep. Trivially, a var can be its own rep.
The solver provides this array once it is done solving. */
unsigned int *var_rep;
struct constraint_stats stats;
/* Find the first varinfo in the same variable as START that overlaps with
OFFSET. Return NULL if we can't find one. */
varinfo_t
first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
{
/* If the offset is outside of the variable, bail out. */
if (offset >= start->fullsize)
return NULL;
/* If we cannot reach offset from start, lookup the first field
and start from there. */
if (start->offset > offset)
start = get_varinfo (start->head);
while (start)
{
/* We may not find a variable in the field list with the actual
offset when we have glommed a structure to a variable.
In that case, however, offset should still be within the size
of the variable. */
if (offset >= start->offset
&& (offset - start->offset) < start->size)
return start;
start = vi_next (start);
}
return NULL;
}
/* Find the first varinfo in the same variable as START that overlaps with
OFFSET. If there is no such varinfo the varinfo directly preceding
OFFSET is returned. */
varinfo_t
first_or_preceding_vi_for_offset (varinfo_t start,
unsigned HOST_WIDE_INT offset)
{
/* If we cannot reach offset from start, lookup the first field
and start from there. */
if (start->offset > offset)
start = get_varinfo (start->head);
/* We may not find a variable in the field list with the actual
offset when we have glommed a structure to a variable.
In that case, however, offset should still be within the size
of the variable.
If we got beyond the offset we look for return the field
directly preceding offset which may be the last field. */
while (start->next
&& offset >= start->offset
&& !((offset - start->offset) < start->size))
start = vi_next (start);
return start;
}
/* Print out constraint C to FILE. */
void
dump_constraint (FILE *file, constraint_t c)
{
if (c->lhs.type == ADDRESSOF)
fprintf (file, "&");
else if (c->lhs.type == DEREF)
fprintf (file, "*");
if (dump_file)
fprintf (file, "%s", get_varinfo (c->lhs.var)->name);
else
fprintf (file, "V%d", c->lhs.var);
if (c->lhs.offset == UNKNOWN_OFFSET)
fprintf (file, " + UNKNOWN");
else if (c->lhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->lhs.offset);
fprintf (file, " = ");
if (c->rhs.type == ADDRESSOF)
fprintf (file, "&");
else if (c->rhs.type == DEREF)
fprintf (file, "*");
if (dump_file)
fprintf (file, "%s", get_varinfo (c->rhs.var)->name);
else
fprintf (file, "V%d", c->rhs.var);
if (c->rhs.offset == UNKNOWN_OFFSET)
fprintf (file, " + UNKNOWN");
else if (c->rhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->rhs.offset);
}
/* Print out constraint C to stderr. */
DEBUG_FUNCTION void
debug_constraint (constraint_t c)
{
dump_constraint (stderr, c);
fprintf (stderr, "\n");
}
/* Print out all constraints to FILE. */
void
dump_constraints (FILE *file, int from)
{
int i;
constraint_t c;
for (i = from; constraints.iterate (i, &c); i++)
if (c)
{
dump_constraint (file, c);
fprintf (file, "\n");
}
}
/* Print out all constraints to stderr. */
DEBUG_FUNCTION void
debug_constraints (void)
{
dump_constraints (stderr, 0);
}
/* Print out the points-to solution for VAR to FILE. */
void
dump_solution_for_var (FILE *file, unsigned int var)
{
varinfo_t vi = get_varinfo (var);
unsigned int i;
bitmap_iterator bi;
/* Dump the solution for unified vars anyway, this avoids difficulties
in scanning dumps in the testsuite. */
fprintf (file, "%s = { ", vi->name);
vi = get_varinfo (var_rep[var]);
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
fprintf (file, "%s ", get_varinfo (i)->name);
fprintf (file, "}");
/* But note when the variable was unified. */
if (vi->id != var)
fprintf (file, " same as %s", vi->name);
fprintf (file, "\n");
}
/* Print the points-to solution for VAR to stderr. */
DEBUG_FUNCTION void
debug_solution_for_var (unsigned int var)
{
dump_solution_for_var (stderr, var);
}
/* Dump stats information to OUTFILE. */
void
dump_sa_stats (FILE *outfile)
{
fprintf (outfile, "Points-to Stats:\n");
fprintf (outfile, "Total vars: %d\n", stats.total_vars);
fprintf (outfile, "Non-pointer vars: %d\n",
stats.nonpointer_vars);
fprintf (outfile, "Statically unified vars: %d\n",
stats.unified_vars_static);
fprintf (outfile, "Dynamically unified vars: %d\n",
stats.unified_vars_dynamic);
fprintf (outfile, "Iterations: %d\n", stats.iterations);
fprintf (outfile, "Number of edges: %d\n", stats.num_edges);
fprintf (outfile, "Number of implicit edges: %d\n",
stats.num_implicit_edges);
fprintf (outfile, "Number of avoided edges: %d\n",
stats.num_avoided_edges);
}
/* Dump points-to information to OUTFILE. */
void
dump_sa_points_to_info (FILE *outfile)
{
fprintf (outfile, "\nPoints-to sets\n\n");
for (unsigned i = 1; i < varmap.length (); i++)
{
varinfo_t vi = get_varinfo (i);
if (!vi->may_have_pointers)
continue;
dump_solution_for_var (outfile, i);
}
}
/* Debug points-to information to stderr. */
DEBUG_FUNCTION void
debug_sa_points_to_info (void)
{
dump_sa_points_to_info (stderr);
}
/* Dump varinfo VI to FILE. */
void
dump_varinfo (FILE *file, varinfo_t vi)
{
if (vi == NULL)
return;
fprintf (file, "%u: %s\n", vi->id, vi->name);
const char *sep = " ";
if (vi->is_artificial_var)
fprintf (file, "%sartificial", sep);
if (vi->is_special_var)
fprintf (file, "%sspecial", sep);
if (vi->is_unknown_size_var)
fprintf (file, "%sunknown-size", sep);
if (vi->is_full_var)
fprintf (file, "%sfull", sep);
if (vi->is_heap_var)
fprintf (file, "%sheap", sep);
if (vi->may_have_pointers)
fprintf (file, "%smay-have-pointers", sep);
if (vi->only_restrict_pointers)
fprintf (file, "%sonly-restrict-pointers", sep);
if (vi->is_restrict_var)
fprintf (file, "%sis-restrict-var", sep);
if (vi->is_global_var)
fprintf (file, "%sglobal", sep);
if (vi->is_ipa_escape_point)
fprintf (file, "%sipa-escape-point", sep);
if (vi->is_fn_info)
fprintf (file, "%sfn-info", sep);
if (vi->ruid)
fprintf (file, "%srestrict-uid:%u", sep, vi->ruid);
if (vi->next)
fprintf (file, "%snext:%u", sep, vi->next);
if (vi->head != vi->id)
fprintf (file, "%shead:%u", sep, vi->head);
if (vi->offset)
fprintf (file, "%soffset:" HOST_WIDE_INT_PRINT_DEC, sep, vi->offset);
if (vi->size != ~HOST_WIDE_INT_0U)
fprintf (file, "%ssize:" HOST_WIDE_INT_PRINT_DEC, sep, vi->size);
if (vi->fullsize != ~HOST_WIDE_INT_0U && vi->fullsize != vi->size)
fprintf (file, "%sfullsize:" HOST_WIDE_INT_PRINT_DEC, sep,
vi->fullsize);
fprintf (file, "\n");
if (vi->solution && !bitmap_empty_p (vi->solution))
{
bitmap_iterator bi;
unsigned i;
fprintf (file, " solution: {");
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
fprintf (file, " %u", i);
fprintf (file, " }\n");
}
if (vi->oldsolution && !bitmap_empty_p (vi->oldsolution)
&& !bitmap_equal_p (vi->solution, vi->oldsolution))
{
bitmap_iterator bi;
unsigned i;
fprintf (file, " oldsolution: {");
EXECUTE_IF_SET_IN_BITMAP (vi->oldsolution, 0, i, bi)
fprintf (file, " %u", i);
fprintf (file, " }\n");
}
}
/* Dump varinfo VI to stderr. */
DEBUG_FUNCTION void
debug_varinfo (varinfo_t vi)
{
dump_varinfo (stderr, vi);
}
/* Dump varmap to FILE. */
void
dump_varmap (FILE *file)
{
if (varmap.length () == 0)
return;
fprintf (file, "variables:\n");
for (unsigned int i = 0; i < varmap.length (); ++i)
{
varinfo_t vi = get_varinfo (i);
dump_varinfo (file, vi);
}
fprintf (file, "\n");
}
/* Dump varmap to stderr. */
DEBUG_FUNCTION void
debug_varmap (void)
{
dump_varmap (stderr);
}
} // namespace pointer_analysis
using namespace pointer_analysis;
static bool use_field_sensitive = true;
static int in_ipa_mode = 0;
static unsigned int create_variable_info_for (tree, const char *, bool);
static varinfo_t lookup_vi_for_tree (tree);
static inline bool type_can_have_subvars (const_tree);
static void make_param_constraints (varinfo_t);
/* Pool of variable info structures. */
static object_allocator<variable_info> variable_info_pool
("Variable info pool");
/* Map varinfo to final pt_solution. */
static hash_map<varinfo_t, pt_solution *> *final_solutions;
static struct obstack final_solutions_obstack;
/* Return a new variable info structure consisting for a variable
named NAME, and using constraint graph node NODE. Append it
to the vector of variable info structures. */
static varinfo_t
new_var_info (tree t, const char *name, bool add_id)
{
unsigned index = varmap.length ();
varinfo_t ret = variable_info_pool.allocate ();
if (dump_file && add_id)
{
char *tempname = xasprintf ("%s(%d)", name, index);
name = ggc_strdup (tempname);
free (tempname);
}
ret->id = index;
ret->name = name;
ret->decl = t;
/* Vars without decl are artificial and do not have sub-variables. */
ret->is_artificial_var = (t == NULL_TREE);
ret->is_special_var = false;
ret->is_unknown_size_var = false;
ret->is_full_var = (t == NULL_TREE);
ret->is_heap_var = false;
ret->may_have_pointers = true;
ret->only_restrict_pointers = false;
ret->is_restrict_var = false;
ret->ruid = 0;
ret->is_global_var = (t == NULL_TREE);
ret->is_ipa_escape_point = false;
ret->is_fn_info = false;
ret->address_taken = false;
if (t && DECL_P (t))
ret->is_global_var = (is_global_var (t)
/* We have to treat even local register variables
as escape points. */
|| (VAR_P (t) && DECL_HARD_REGISTER (t)));
ret->is_reg_var = (t && TREE_CODE (t) == SSA_NAME);
ret->solution = BITMAP_ALLOC (&pta_obstack);
ret->oldsolution = NULL;
ret->next = 0;
ret->shadow_var_uid = 0;
ret->head = ret->id;
stats.total_vars++;
varmap.safe_push (ret);
return ret;
}
/* A map mapping call statements to per-stmt variables for uses
and clobbers specific to the call. */
static hash_map<gimple *, varinfo_t> *call_stmt_vars;
/* Lookup or create the variable for the call statement CALL. */
static varinfo_t
get_call_vi (gcall *call)
{
varinfo_t vi, vi2;
bool existed;
varinfo_t *slot_p = &call_stmt_vars->get_or_insert (call, &existed);
if (existed)
return *slot_p;
vi = new_var_info (NULL_TREE, "CALLUSED", true);
vi->offset = 0;
vi->size = 1;
vi->fullsize = 2;
vi->is_full_var = true;
vi->is_reg_var = true;
vi2 = new_var_info (NULL_TREE, "CALLCLOBBERED", true);
vi2->offset = 1;
vi2->size = 1;
vi2->fullsize = 2;
vi2->is_full_var = true;
vi2->is_reg_var = true;
vi->next = vi2->id;
*slot_p = vi;
return vi;
}
/* Lookup the variable for the call statement CALL representing
the uses. Returns NULL if there is nothing special about this call. */
static varinfo_t
lookup_call_use_vi (gcall *call)
{
varinfo_t *slot_p = call_stmt_vars->get (call);
if (slot_p)
return *slot_p;
return NULL;
}
/* Lookup the variable for the call statement CALL representing
the clobbers. Returns NULL if there is nothing special about this call. */
static varinfo_t
lookup_call_clobber_vi (gcall *call)
{
varinfo_t uses = lookup_call_use_vi (call);
if (!uses)
return NULL;
return vi_next (uses);
}
/* Lookup or create the variable for the call statement CALL representing
the uses. */
static varinfo_t
get_call_use_vi (gcall *call)
{
return get_call_vi (call);
}
/* Lookup or create the variable for the call statement CALL representing
the clobbers. */
static varinfo_t ATTRIBUTE_UNUSED
get_call_clobber_vi (gcall *call)
{
return vi_next (get_call_vi (call));
}
static void get_constraint_for_1 (tree, vec<ce_s> *, bool, bool);
static void get_constraint_for (tree, vec<ce_s> *);
static void get_constraint_for_rhs (tree, vec<ce_s> *);
static void do_deref (vec<ce_s> *);
/* Allocator for 'constraints' vector. */
static object_allocator<constraint> constraint_pool ("Constraint pool");
/* Create a new constraint consisting of LHS and RHS expressions. */
static constraint_t
new_constraint (const struct constraint_expr lhs,
const struct constraint_expr rhs)
{
constraint_t ret = constraint_pool.allocate ();
ret->lhs = lhs;
ret->rhs = rhs;
return ret;
}
/* Insert ID as the variable id for tree T in the vi_for_tree map. */
static void
insert_vi_for_tree (tree t, varinfo_t vi)
{
gcc_assert (vi);
bool existed = vi_for_tree->put (t, vi);
gcc_assert (!existed);
}
/* Find the variable info for tree T in VI_FOR_TREE. If T does not
exist in the map, return NULL, otherwise, return the varinfo we found. */
static varinfo_t
lookup_vi_for_tree (tree t)
{
varinfo_t *slot = vi_for_tree->get (t);
if (slot == NULL)
return NULL;
return *slot;
}
/* Return a printable name for DECL. */
static const char *
alias_get_name (tree decl)
{
const char *res = "NULL";
if (dump_file)
{
char *temp = NULL;
if (TREE_CODE (decl) == SSA_NAME)
{
res = get_name (decl);
temp = xasprintf ("%s_%u", res ? res : "", SSA_NAME_VERSION (decl));
}
else if (HAS_DECL_ASSEMBLER_NAME_P (decl)
&& DECL_ASSEMBLER_NAME_SET_P (decl))
res = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME_RAW (decl));
else if (DECL_P (decl))
{
res = get_name (decl);
if (!res)
temp = xasprintf ("D.%u", DECL_UID (decl));
}
if (temp)
{
res = ggc_strdup (temp);
free (temp);
}
}
return res;
}
/* Find the variable id for tree T in the map.
If T doesn't exist in the map, create an entry for it and return it. */
static varinfo_t
get_vi_for_tree (tree t)
{
varinfo_t *slot = vi_for_tree->get (t);
if (slot == NULL)
{
unsigned int id = create_variable_info_for (t, alias_get_name (t), false);
return get_varinfo (id);
}
return *slot;
}
/* Get a scalar constraint expression for a new temporary variable. */
static struct constraint_expr
new_scalar_tmp_constraint_exp (const char *name, bool add_id)
{
struct constraint_expr tmp;
varinfo_t vi;
vi = new_var_info (NULL_TREE, name, add_id);
vi->offset = 0;
vi->size = -1;
vi->fullsize = -1;
vi->is_full_var = 1;
vi->is_reg_var = 1;
tmp.var = vi->id;
tmp.type = SCALAR;
tmp.offset = 0;
return tmp;
}
/* Get a constraint expression vector from an SSA_VAR_P node.
If address_p is true, the result will be taken its address of. */
static void
get_constraint_for_ssa_var (tree t, vec<ce_s> *results, bool address_p)
{
struct constraint_expr cexpr;
varinfo_t vi;
/* We allow FUNCTION_DECLs here even though it doesn't make much sense. */
gcc_assert (TREE_CODE (t) == SSA_NAME || DECL_P (t));
if (TREE_CODE (t) == SSA_NAME
&& SSA_NAME_IS_DEFAULT_DEF (t))
{
/* For parameters, get at the points-to set for the actual parm
decl. */
if (TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
|| TREE_CODE (SSA_NAME_VAR (t)) == RESULT_DECL)
{
get_constraint_for_ssa_var (SSA_NAME_VAR (t), results, address_p);
return;
}
/* For undefined SSA names return nothing. */
else if (!ssa_defined_default_def_p (t))
{
cexpr.var = nothing_id;
cexpr.type = SCALAR;
cexpr.offset = 0;
results->safe_push (cexpr);
return;
}
}
/* For global variables resort to the alias target. */
if (VAR_P (t) && (TREE_STATIC (t) || DECL_EXTERNAL (t)))
{
varpool_node *node = varpool_node::get (t);
if (node && node->alias && node->analyzed)
{
node = node->ultimate_alias_target ();
/* Canonicalize the PT uid of all aliases to the ultimate target.
??? Hopefully the set of aliases can't change in a way that
changes the ultimate alias target. */
gcc_assert ((! DECL_PT_UID_SET_P (node->decl)
|| DECL_PT_UID (node->decl) == DECL_UID (node->decl))
&& (! DECL_PT_UID_SET_P (t)
|| DECL_PT_UID (t) == DECL_UID (node->decl)));
DECL_PT_UID (t) = DECL_UID (node->decl);
t = node->decl;
}
/* If this is decl may bind to NULL note that. */
if (address_p
&& (! node || ! node->nonzero_address ()))
{
cexpr.var = nothing_id;
cexpr.type = SCALAR;
cexpr.offset = 0;
results->safe_push (cexpr);
}
}
vi = get_vi_for_tree (t);
cexpr.var = vi->id;
cexpr.type = SCALAR;
cexpr.offset = 0;
/* If we are not taking the address of the constraint expr, add all
sub-fiels of the variable as well. */
if (!address_p
&& !vi->is_full_var)
{
for (; vi; vi = vi_next (vi))
{
cexpr.var = vi->id;
results->safe_push (cexpr);
}
return;
}
results->safe_push (cexpr);
}
/* Process constraint T, performing various simplifications and then
adding it to our list of overall constraints. */
static void
process_constraint (constraint_t t)
{
struct constraint_expr rhs = t->rhs;
struct constraint_expr lhs = t->lhs;
gcc_assert (rhs.var < varmap.length ());
gcc_assert (lhs.var < varmap.length ());
/* If we didn't get any useful constraint from the lhs we get
&ANYTHING as fallback from get_constraint_for. Deal with
it here by turning it into *ANYTHING. */
if (lhs.type == ADDRESSOF
&& lhs.var == anything_id)
t->lhs.type = lhs.type = DEREF;
/* ADDRESSOF on the lhs is invalid. */
gcc_assert (lhs.type != ADDRESSOF);
/* We shouldn't add constraints from things that cannot have pointers.
It's not completely trivial to avoid in the callers, so do it here. */
if (rhs.type != ADDRESSOF
&& !get_varinfo (rhs.var)->may_have_pointers)
return;
/* Likewise adding to the solution of a non-pointer var isn't useful. */
if (!get_varinfo (lhs.var)->may_have_pointers)
return;
/* This can happen in our IR with things like n->a = *p. */
if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
{
/* Split into tmp = *rhs, *lhs = tmp. */
struct constraint_expr tmplhs;
tmplhs = new_scalar_tmp_constraint_exp ("doubledereftmp", true);
process_constraint (new_constraint (tmplhs, rhs));
process_constraint (new_constraint (lhs, tmplhs));
}
else if ((rhs.type != SCALAR || rhs.offset != 0) && lhs.type == DEREF)
{
/* Split into tmp = &rhs, *lhs = tmp. */
struct constraint_expr tmplhs;
tmplhs = new_scalar_tmp_constraint_exp ("derefaddrtmp", true);
process_constraint (new_constraint (tmplhs, rhs));
process_constraint (new_constraint (lhs, tmplhs));
}
else
{
gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
if (rhs.type == ADDRESSOF)
get_varinfo (get_varinfo (rhs.var)->head)->address_taken = true;
constraints.safe_push (t);
}
}
/* Return the position, in bits, of FIELD_DECL from the beginning of its
structure. */
static unsigned HOST_WIDE_INT
bitpos_of_field (const tree fdecl)
{
if (!tree_fits_uhwi_p (DECL_FIELD_OFFSET (fdecl))
|| !tree_fits_uhwi_p (DECL_FIELD_BIT_OFFSET (fdecl)))
return -1;
return (tree_to_uhwi (DECL_FIELD_OFFSET (fdecl)) * BITS_PER_UNIT
+ tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fdecl)));
}
/* Get constraint expressions for offsetting PTR by OFFSET. Stores the
resulting constraint expressions in *RESULTS. */
static void
get_constraint_for_ptr_offset (tree ptr, tree offset,
vec<ce_s> *results)
{
struct constraint_expr c;
unsigned int j, n;
HOST_WIDE_INT rhsoffset;
/* If we do not do field-sensitive PTA adding offsets to pointers
does not change the points-to solution. */
if (!use_field_sensitive)
{
get_constraint_for_rhs (ptr, results);
return;
}
/* If the offset is not a non-negative integer constant that fits
in a HOST_WIDE_INT, we have to fall back to a conservative
solution which includes all sub-fields of all pointed-to
variables of ptr. */
if (offset == NULL_TREE
|| TREE_CODE (offset) != INTEGER_CST)
rhsoffset = UNKNOWN_OFFSET;
else
{
/* Sign-extend the offset. */
offset_int soffset = offset_int::from (wi::to_wide (offset), SIGNED);
if (!wi::fits_shwi_p (soffset))
rhsoffset = UNKNOWN_OFFSET;
else
{
/* Make sure the bit-offset also fits. */
HOST_WIDE_INT rhsunitoffset = soffset.to_shwi ();
rhsoffset = rhsunitoffset * (unsigned HOST_WIDE_INT) BITS_PER_UNIT;
if (rhsunitoffset != rhsoffset / BITS_PER_UNIT)
rhsoffset = UNKNOWN_OFFSET;
}
}
get_constraint_for_rhs (ptr, results);
if (rhsoffset == 0)
return;
/* As we are eventually appending to the solution do not use
vec::iterate here. */
n = results->length ();
for (j = 0; j < n; j++)
{
varinfo_t curr;
c = (*results)[j];
curr = get_varinfo (c.var);
if (c.type == ADDRESSOF
/* If this varinfo represents a full variable just use it. */
&& curr->is_full_var)
;
else if (c.type == ADDRESSOF
/* If we do not know the offset add all subfields. */
&& rhsoffset == UNKNOWN_OFFSET)
{
varinfo_t temp = get_varinfo (curr->head);
do
{
struct constraint_expr c2;
c2.var = temp->id;
c2.type = ADDRESSOF;
c2.offset = 0;
if (c2.var != c.var)
results->safe_push (c2);
temp = vi_next (temp);
}
while (temp);
}
else if (c.type == ADDRESSOF)
{
varinfo_t temp;
unsigned HOST_WIDE_INT offset = curr->offset + rhsoffset;
/* If curr->offset + rhsoffset is less than zero adjust it. */
if (rhsoffset < 0
&& curr->offset < offset)
offset = 0;
/* We have to include all fields that overlap the current
field shifted by rhsoffset. And we include at least
the last or the first field of the variable to represent
reachability of off-bound addresses, in particular &object + 1,
conservatively correct. */
temp = first_or_preceding_vi_for_offset (curr, offset);
c.var = temp->id;
c.offset = 0;
temp = vi_next (temp);
while (temp
&& temp->offset < offset + curr->size)
{
struct constraint_expr c2;
c2.var = temp->id;
c2.type = ADDRESSOF;
c2.offset = 0;
results->safe_push (c2);
temp = vi_next (temp);
}
}
else if (c.type == SCALAR)
{
gcc_assert (c.offset == 0);
c.offset = rhsoffset;
}
else
/* We shouldn't get any DEREFs here. */
gcc_unreachable ();
(*results)[j] = c;
}
}
/* Given a COMPONENT_REF T, return the constraint_expr vector for it.
If address_p is true the result will be taken its address of.
If lhs_p is true then the constraint expression is assumed to be used
as the lhs. */
static void
get_constraint_for_component_ref (tree t, vec<ce_s> *results,
bool address_p, bool lhs_p)
{
tree orig_t = t;
poly_int64 bitsize = -1;
poly_int64 bitmaxsize = -1;
poly_int64 bitpos;
bool reverse;
tree forzero;
/* Some people like to do cute things like take the address of
&0->a.b. */
forzero = t;
while (handled_component_p (forzero)
|| INDIRECT_REF_P (forzero)
|| TREE_CODE (forzero) == MEM_REF)
forzero = TREE_OPERAND (forzero, 0);
if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
{
struct constraint_expr temp;
temp.offset = 0;
temp.var = integer_id;
temp.type = SCALAR;
results->safe_push (temp);
return;
}
t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize, &reverse);
/* We can end up here for component references on a
VIEW_CONVERT_EXPR <>(&foobar) or things like a
BIT_FIELD_REF <&MEM[(void *)&b + 4B], ...>. So for
symbolic constants simply give up. */
if (TREE_CODE (t) == ADDR_EXPR)
{
constraint_expr result;
result.type = SCALAR;
result.var = anything_id;
result.offset = 0;
results->safe_push (result);
return;
}
/* Avoid creating pointer-offset constraints, so handle MEM_REF
offsets directly. Pretend to take the address of the base,
we'll take care of adding the required subset of sub-fields below. */
if (TREE_CODE (t) == MEM_REF
&& !integer_zerop (TREE_OPERAND (t, 0)))
{
poly_offset_int off = mem_ref_offset (t);
off <<= LOG2_BITS_PER_UNIT;
off += bitpos;
poly_int64 off_hwi;
if (off.to_shwi (&off_hwi))
bitpos = off_hwi;
else
{
bitpos = 0;
bitmaxsize = -1;
}
get_constraint_for_1 (TREE_OPERAND (t, 0), results, false, lhs_p);
do_deref (results);
}
else
get_constraint_for_1 (t, results, true, lhs_p);
/* Strip off nothing_id. */
if (results->length () == 2)
{
gcc_assert ((*results)[0].var == nothing_id);
results->unordered_remove (0);
}
gcc_assert (results->length () == 1);
struct constraint_expr &result = results->last ();
if (result.type == SCALAR
&& get_varinfo (result.var)->is_full_var)
/* For single-field vars do not bother about the offset. */
result.offset = 0;
else if (result.type == SCALAR)
{
/* In languages like C, you can access one past the end of an
array. You aren't allowed to dereference it, so we can
ignore this constraint. When we handle pointer subtraction,
we may have to do something cute here. */
if (maybe_lt (poly_uint64 (bitpos), get_varinfo (result.var)->fullsize)
&& maybe_ne (bitmaxsize, 0))
{
/* It's also not true that the constraint will actually start at the
right offset, it may start in some padding. We only care about
setting the constraint to the first actual field it touches, so
walk to find it. */
struct constraint_expr cexpr = result;
varinfo_t curr;
results->pop ();
cexpr.offset = 0;
for (curr = get_varinfo (cexpr.var); curr; curr = vi_next (curr))
{
if (ranges_maybe_overlap_p (poly_int64 (curr->offset),
curr->size, bitpos, bitmaxsize))
{
cexpr.var = curr->id;
results->safe_push (cexpr);
if (address_p)
break;
}
}
/* If we are going to take the address of this field then
to be able to compute reachability correctly add at least
the last field of the variable. */
if (address_p && results->length () == 0)
{
curr = get_varinfo (cexpr.var);
while (curr->next != 0)
curr = vi_next (curr);
cexpr.var = curr->id;
results->safe_push (cexpr);
}
else if (results->length () == 0)
/* Assert that we found *some* field there. The user couldn't be
accessing *only* padding. */
/* Still the user could access one past the end of an array
embedded in a struct resulting in accessing *only* padding. */
/* Or accessing only padding via type-punning to a type
that has a filed just in padding space. */
{
cexpr.type = SCALAR;
cexpr.var = anything_id;
cexpr.offset = 0;
results->safe_push (cexpr);
}
}
else if (known_eq (bitmaxsize, 0))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Access to zero-sized part of variable, "
"ignoring\n");
}
else
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Access to past the end of variable, ignoring\n");
}
else if (result.type == DEREF)
{
/* If we do not know exactly where the access goes say so. Note
that only for non-structure accesses we know that we access
at most one subfiled of any variable. */
HOST_WIDE_INT const_bitpos;
if (!bitpos.is_constant (&const_bitpos)
|| const_bitpos == -1
|| maybe_ne (bitsize, bitmaxsize)
|| AGGREGATE_TYPE_P (TREE_TYPE (orig_t))
|| result.offset == UNKNOWN_OFFSET)
result.offset = UNKNOWN_OFFSET;
else
result.offset += const_bitpos;
}
else if (result.type == ADDRESSOF)
{
/* We can end up here for component references on constants like
VIEW_CONVERT_EXPR <>({ 0, 1, 2, 3 })[i]. */
result.type = SCALAR;
result.var = anything_id;
result.offset = 0;
}
else
gcc_unreachable ();
}
/* Dereference the constraint expression CONS, and return the result.
DEREF (ADDRESSOF) = SCALAR
DEREF (SCALAR) = DEREF
DEREF (DEREF) = (temp = DEREF1; result = DEREF (temp))
This is needed so that we can handle dereferencing DEREF constraints. */
static void
do_deref (vec<ce_s> *constraints)
{
struct constraint_expr *c;
unsigned int i = 0;
FOR_EACH_VEC_ELT (*constraints, i, c)
{
if (c->type == SCALAR)
c->type = DEREF;
else if (c->type == ADDRESSOF)
c->type = SCALAR;
else if (c->type == DEREF)
{
struct constraint_expr tmplhs;
tmplhs = new_scalar_tmp_constraint_exp ("dereftmp", true);
process_constraint (new_constraint (tmplhs, *c));
c->var = tmplhs.var;
}
else
gcc_unreachable ();
}
}
/* Given a tree T, return the constraint expression for taking the
address of it. */
static void
get_constraint_for_address_of (tree t, vec<ce_s> *results)
{
struct constraint_expr *c;
unsigned int i;
get_constraint_for_1 (t, results, true, true);
FOR_EACH_VEC_ELT (*results, i, c)
{
if (c->type == DEREF)
c->type = SCALAR;
else
c->type = ADDRESSOF;
}
}
/* Given a tree T, return the constraint expression for it. */
static void
get_constraint_for_1 (tree t, vec<ce_s> *results, bool address_p,
bool lhs_p)
{
struct constraint_expr temp;
/* x = integer is all glommed to a single variable, which doesn't
point to anything by itself. That is, of course, unless it is an
integer constant being treated as a pointer, in which case, we
will return that this is really the addressof anything. This
happens below, since it will fall into the default case. The only
case we know something about an integer treated like a pointer is
when it is the NULL pointer, and then we just say it points to
NULL.
Do not do that if -fno-delete-null-pointer-checks though, because
in that case *NULL does not fail, so it _should_ alias *anything.
It is not worth adding a new option or renaming the existing one,
since this case is relatively obscure. */
if ((TREE_CODE (t) == INTEGER_CST
&& integer_zerop (t))
/* The only valid CONSTRUCTORs in gimple with pointer typed
elements are zero-initializer. But in IPA mode we also
process global initializers, so verify at least. */
|| (TREE_CODE (t) == CONSTRUCTOR
&& CONSTRUCTOR_NELTS (t) == 0))
{
if (flag_delete_null_pointer_checks)
temp.var = nothing_id;
else
temp.var = nonlocal_id;
temp.type = ADDRESSOF;
temp.offset = 0;
results->safe_push (temp);
return;
}
/* String constants are read-only, ideally we'd have a CONST_DECL
for those. */
if (TREE_CODE (t) == STRING_CST)
{
temp.var = string_id;
temp.type = SCALAR;
temp.offset = 0;
results->safe_push (temp);
return;
}
switch (TREE_CODE_CLASS (TREE_CODE (t)))
{
case tcc_expression:
{
switch (TREE_CODE (t))
{
case ADDR_EXPR:
get_constraint_for_address_of (TREE_OPERAND (t, 0), results);
return;
default:;
}
break;
}
case tcc_reference:
{
if (!lhs_p && TREE_THIS_VOLATILE (t))
/* Fall back to anything. */
break;
switch (TREE_CODE (t))
{
case MEM_REF:
{
struct constraint_expr cs;
varinfo_t vi, curr;
get_constraint_for_ptr_offset (TREE_OPERAND (t, 0),
TREE_OPERAND (t, 1), results);
do_deref (results);
/* If we are not taking the address then make sure to process
all subvariables we might access. */
if (address_p)
return;
cs = results->last ();
if (cs.type == DEREF
&& type_can_have_subvars (TREE_TYPE (t)))
{
/* For dereferences this means we have to defer it
to solving time. */
results->last ().offset = UNKNOWN_OFFSET;
return;
}
if (cs.type != SCALAR)
return;
vi = get_varinfo (cs.var);
curr = vi_next (vi);
if (!vi->is_full_var
&& curr)
{
unsigned HOST_WIDE_INT size;
if (tree_fits_uhwi_p (TYPE_SIZE (TREE_TYPE (t))))
size = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (t)));
else
size = -1;
for (; curr; curr = vi_next (curr))
{
/* The start of the access might happen anywhere
within vi, so conservatively assume it was
at its end. */
if (curr->offset - (vi->offset + vi->size - 1) < size)
{
cs.var = curr->id;
results->safe_push (cs);
}
else
break;
}
}
return;
}
case ARRAY_REF:
case ARRAY_RANGE_REF:
case COMPONENT_REF:
case IMAGPART_EXPR:
case REALPART_EXPR:
case BIT_FIELD_REF:
get_constraint_for_component_ref (t, results, address_p, lhs_p);
return;
case VIEW_CONVERT_EXPR:
get_constraint_for_1 (TREE_OPERAND (t, 0), results, address_p,
lhs_p);
return;
/* We are missing handling for TARGET_MEM_REF here. */
default:;
}
break;
}
case tcc_exceptional:
{
switch (TREE_CODE (t))
{
case SSA_NAME:
{
get_constraint_for_ssa_var (t, results, address_p);
return;
}
case CONSTRUCTOR:
{
unsigned int i;
tree val;
auto_vec<ce_s> tmp;
FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
{
struct constraint_expr *rhsp;
unsigned j;
get_constraint_for_1 (val, &tmp, address_p, lhs_p);
FOR_EACH_VEC_ELT (tmp, j, rhsp)
results->safe_push (*rhsp);
tmp.truncate (0);
}
/* We do not know whether the constructor was complete,
so technically we have to add &NOTHING or &ANYTHING
like we do for an empty constructor as well. */
return;
}
default:;
}
break;
}
case tcc_declaration:
{
if (!lhs_p && VAR_P (t) && TREE_THIS_VOLATILE (t))
/* Fall back to anything. */
break;
get_constraint_for_ssa_var (t, results, address_p);
return;
}
case tcc_constant:
{
/* We cannot refer to automatic variables through constants. */
temp.type = ADDRESSOF;
temp.var = nonlocal_id;
temp.offset = 0;
results->safe_push (temp);
return;
}
default:;
}
/* The default fallback is a constraint from anything. */
temp.type = ADDRESSOF;
temp.var = anything_id;
temp.offset = 0;
results->safe_push (temp);
}
/* Given a gimple tree T, return the constraint expression vector for it. */
static void
get_constraint_for (tree t, vec<ce_s> *results)
{
gcc_assert (results->length () == 0);
get_constraint_for_1 (t, results, false, true);
}
/* Given a gimple tree T, return the constraint expression vector for it
to be used as the rhs of a constraint. */
static void
get_constraint_for_rhs (tree t, vec<ce_s> *results)
{
gcc_assert (results->length () == 0);
get_constraint_for_1 (t, results, false, false);
}
/* Efficiently generates constraints from all entries in *RHSC to all
entries in *LHSC. */
static void
process_all_all_constraints (const vec<ce_s> &lhsc,
const vec<ce_s> &rhsc)
{
struct constraint_expr *lhsp, *rhsp;
unsigned i, j;
if (lhsc.length () <= 1 || rhsc.length () <= 1)
{
FOR_EACH_VEC_ELT (lhsc, i, lhsp)
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (*lhsp, *rhsp));
}
else
{
struct constraint_expr tmp;
tmp = new_scalar_tmp_constraint_exp ("allalltmp", true);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (tmp, *rhsp));
FOR_EACH_VEC_ELT (lhsc, i, lhsp)
process_constraint (new_constraint (*lhsp, tmp));
}
}
/* Handle aggregate copies by expanding into copies of the respective
fields of the structures. */
static void
do_structure_copy (tree lhsop, tree rhsop)
{
struct constraint_expr *lhsp, *rhsp;
auto_vec<ce_s> lhsc;
auto_vec<ce_s> rhsc;
unsigned j;
get_constraint_for (lhsop, &lhsc);
get_constraint_for_rhs (rhsop, &rhsc);
lhsp = &lhsc[0];
rhsp = &rhsc[0];
if (lhsp->type == DEREF
|| (lhsp->type == ADDRESSOF && lhsp->var == anything_id)
|| rhsp->type == DEREF)
{
if (lhsp->type == DEREF)
{
gcc_assert (lhsc.length () == 1);
lhsp->offset = UNKNOWN_OFFSET;
}
if (rhsp->type == DEREF)
{
gcc_assert (rhsc.length () == 1);
rhsp->offset = UNKNOWN_OFFSET;
}
process_all_all_constraints (lhsc, rhsc);
}
else if (lhsp->type == SCALAR
&& (rhsp->type == SCALAR
|| rhsp->type == ADDRESSOF))
{
HOST_WIDE_INT lhssize, lhsoffset;
HOST_WIDE_INT rhssize, rhsoffset;
bool reverse;
unsigned k = 0;
if (!get_ref_base_and_extent_hwi (lhsop, &lhsoffset, &lhssize, &reverse)
|| !get_ref_base_and_extent_hwi (rhsop, &rhsoffset, &rhssize,
&reverse))
{
process_all_all_constraints (lhsc, rhsc);
return;
}
for (j = 0; lhsc.iterate (j, &lhsp);)
{
varinfo_t lhsv, rhsv;
rhsp = &rhsc[k];
lhsv = get_varinfo (lhsp->var);
rhsv = get_varinfo (rhsp->var);
if (lhsv->may_have_pointers
&& (lhsv->is_full_var
|| rhsv->is_full_var
|| ranges_overlap_p (lhsv->offset + rhsoffset, lhsv->size,
rhsv->offset + lhsoffset, rhsv->size)))
process_constraint (new_constraint (*lhsp, *rhsp));
if (!rhsv->is_full_var
&& (lhsv->is_full_var
|| (lhsv->offset + rhsoffset + lhsv->size
> rhsv->offset + lhsoffset + rhsv->size)))
{
++k;
if (k >= rhsc.length ())
break;
}
else
++j;
}
}
else
gcc_unreachable ();
}
/* Create constraints ID = { rhsc }. */
static void
make_constraints_to (unsigned id, const vec<ce_s> &rhsc)
{
struct constraint_expr *c;
struct constraint_expr includes;
unsigned int j;
includes.var = id;
includes.offset = 0;
includes.type = SCALAR;
FOR_EACH_VEC_ELT (rhsc, j, c)
process_constraint (new_constraint (includes, *c));
}
/* Create a constraint ID = OP. */
static void
make_constraint_to (unsigned id, tree op)
{
auto_vec<ce_s> rhsc;
get_constraint_for_rhs (op, &rhsc);
make_constraints_to (id, rhsc);
}
/* Create a constraint ID = &FROM. */
static void
make_constraint_from (varinfo_t vi, int from)
{
struct constraint_expr lhs, rhs;
lhs.var = vi->id;
lhs.offset = 0;
lhs.type = SCALAR;
rhs.var = from;
rhs.offset = 0;
rhs.type = ADDRESSOF;
process_constraint (new_constraint (lhs, rhs));
}
/* Create a constraint ID = FROM. */
static void
make_copy_constraint (varinfo_t vi, int from)
{
struct constraint_expr lhs, rhs;
lhs.var = vi->id;
lhs.offset = 0;
lhs.type = SCALAR;
rhs.var = from;
rhs.offset = 0;
rhs.type = SCALAR;
process_constraint (new_constraint (lhs, rhs));
}
/* Make constraints necessary to make OP escape. */
static void
make_escape_constraint (tree op)
{
make_constraint_to (escaped_id, op);
}
/* Make constraint necessary to make all indirect references
from VI escape. */
static void
make_indirect_escape_constraint (varinfo_t vi)
{
struct constraint_expr lhs, rhs;
/* escaped = *(VAR + UNKNOWN); */
lhs.type = SCALAR;
lhs.var = escaped_id;
lhs.offset = 0;
rhs.type = DEREF;
rhs.var = vi->id;
rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
}
/* Add constraints to that the solution of VI is transitively closed. */
static void
make_transitive_closure_constraints (varinfo_t vi)
{
struct constraint_expr lhs, rhs;
/* VAR = *(VAR + UNKNOWN); */
lhs.type = SCALAR;
lhs.var = vi->id;
lhs.offset = 0;
rhs.type = DEREF;
rhs.var = vi->id;
rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
}
/* Add constraints to that the solution of VI has all subvariables added. */
static void
make_any_offset_constraints (varinfo_t vi)
{
struct constraint_expr lhs, rhs;
/* VAR = VAR + UNKNOWN; */
lhs.type = SCALAR;
lhs.var = vi->id;
lhs.offset = 0;
rhs.type = SCALAR;
rhs.var = vi->id;
rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
}
/* Temporary storage for fake var decls. */
struct obstack fake_var_decl_obstack;
/* Build a fake VAR_DECL acting as referrer to a DECL_UID. */
static tree
build_fake_var_decl (tree type)
{
tree decl = (tree) XOBNEW (&fake_var_decl_obstack, struct tree_var_decl);
memset (decl, 0, sizeof (struct tree_var_decl));
TREE_SET_CODE (decl, VAR_DECL);
TREE_TYPE (decl) = type;
DECL_UID (decl) = allocate_decl_uid ();
SET_DECL_PT_UID (decl, -1);
layout_decl (decl, 0);
return decl;
}
/* Create a new artificial heap variable with NAME.
Return the created variable. */
static varinfo_t
make_heapvar (const char *name, bool add_id)
{
varinfo_t vi;
tree heapvar;
heapvar = build_fake_var_decl (ptr_type_node);
DECL_EXTERNAL (heapvar) = 1;
vi = new_var_info (heapvar, name, add_id);
vi->is_heap_var = true;
vi->is_unknown_size_var = true;
vi->offset = 0;
vi->fullsize = ~0;
vi->size = ~0;
vi->is_full_var = true;
insert_vi_for_tree (heapvar, vi);
return vi;
}
/* Create a new artificial heap variable with NAME and make a
constraint from it to LHS. Set flags according to a tag used
for tracking restrict pointers. */
static varinfo_t
make_constraint_from_restrict (varinfo_t lhs, const char *name, bool add_id)
{
varinfo_t vi = make_heapvar (name, add_id);
vi->is_restrict_var = 1;
vi->is_global_var = 1;
vi->may_have_pointers = 1;
make_constraint_from (lhs, vi->id);
return vi;
}
/* Create a new artificial heap variable with NAME and make a
constraint from it to LHS. Set flags according to a tag used
for tracking restrict pointers and make the artificial heap
point to global memory. */
static varinfo_t
make_constraint_from_global_restrict (varinfo_t lhs, const char *name,
bool add_id)
{
varinfo_t vi = make_constraint_from_restrict (lhs, name, add_id);
make_copy_constraint (vi, nonlocal_id);
return vi;
}
/* In IPA mode there are varinfos for different aspects of reach
function designator. One for the points-to set of the return
value, one for the variables that are clobbered by the function,
one for its uses and one for each parameter (including a single
glob for remaining variadic arguments). */
enum { fi_clobbers = 1, fi_uses = 2,
fi_static_chain = 3, fi_result = 4, fi_parm_base = 5 };
/* Get a constraint for the requested part of a function designator FI
when operating in IPA mode. */
static struct constraint_expr
get_function_part_constraint (varinfo_t fi, unsigned part)
{
struct constraint_expr c;
gcc_assert (in_ipa_mode);
if (fi->id == anything_id)
{
/* ??? We probably should have a ANYFN special variable. */
c.var = anything_id;
c.offset = 0;
c.type = SCALAR;
}
else if (fi->decl && TREE_CODE (fi->decl) == FUNCTION_DECL)
{
varinfo_t ai = first_vi_for_offset (fi, part);
if (ai)
c.var = ai->id;
else
c.var = anything_id;
c.offset = 0;
c.type = SCALAR;
}
else
{
c.var = fi->id;
c.offset = part;
c.type = DEREF;
}
return c;
}
/* Produce constraints for argument ARG of call STMT with eaf flags
FLAGS. RESULTS is array holding constraints for return value.
CALLESCAPE_ID is variable where call loocal escapes are added.
WRITES_GLOVEL_MEMORY is true if callee may write global memory. */
static void
handle_call_arg (gcall *stmt, tree arg, vec<ce_s> *results, int flags,
int callescape_id, bool writes_global_memory)
{
int relevant_indirect_flags = EAF_NO_INDIRECT_CLOBBER | EAF_NO_INDIRECT_READ
| EAF_NO_INDIRECT_ESCAPE;
int relevant_flags = relevant_indirect_flags
| EAF_NO_DIRECT_CLOBBER
| EAF_NO_DIRECT_READ
| EAF_NO_DIRECT_ESCAPE;
if (gimple_call_lhs (stmt))
{
relevant_flags |= EAF_NOT_RETURNED_DIRECTLY | EAF_NOT_RETURNED_INDIRECTLY;
relevant_indirect_flags |= EAF_NOT_RETURNED_INDIRECTLY;
/* If value is never read from it can not be returned indirectly
(except through the escape solution).
For all flags we get these implications right except for
not_returned because we miss return functions in ipa-prop. */
if (flags & EAF_NO_DIRECT_READ)
flags |= EAF_NOT_RETURNED_INDIRECTLY;
}
/* If the argument is not used we can ignore it.
Similarly argument is invisile for us if it not clobbered, does not
escape, is not read and can not be returned. */
if ((flags & EAF_UNUSED) || ((flags & relevant_flags) == relevant_flags))
return;
/* Produce varinfo for direct accesses to ARG. */
varinfo_t tem = new_var_info (NULL_TREE, "callarg", true);
tem->is_reg_var = true;
make_constraint_to (tem->id, arg);
make_any_offset_constraints (tem);
bool callarg_transitive = false;
/* As an compile time optimization if we make no difference between
direct and indirect accesses make arg transitively closed.
This avoids the need to build indir arg and do everything twice. */
if (((flags & EAF_NO_INDIRECT_CLOBBER) != 0)
== ((flags & EAF_NO_DIRECT_CLOBBER) != 0)
&& (((flags & EAF_NO_INDIRECT_READ) != 0)
== ((flags & EAF_NO_DIRECT_READ) != 0))
&& (((flags & EAF_NO_INDIRECT_ESCAPE) != 0)
== ((flags & EAF_NO_DIRECT_ESCAPE) != 0))
&& (((flags & EAF_NOT_RETURNED_INDIRECTLY) != 0)
== ((flags & EAF_NOT_RETURNED_DIRECTLY) != 0)))
{
make_transitive_closure_constraints (tem);
callarg_transitive = true;
}
/* If necessary, produce varinfo for indirect accesses to ARG. */
varinfo_t indir_tem = NULL;
if (!callarg_transitive
&& (flags & relevant_indirect_flags) != relevant_indirect_flags)
{
struct constraint_expr lhs, rhs;
indir_tem = new_var_info (NULL_TREE, "indircallarg", true);
indir_tem->is_reg_var = true;
/* indir_term = *tem. */
lhs.type = SCALAR;
lhs.var = indir_tem->id;
lhs.offset = 0;
rhs.type = DEREF;
rhs.var = tem->id;
rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
make_any_offset_constraints (indir_tem);
/* If we do not read indirectly there is no need for transitive closure.
We know there is only one level of indirection. */
if (!(flags & EAF_NO_INDIRECT_READ))
make_transitive_closure_constraints (indir_tem);
gcc_checking_assert (!(flags & EAF_NO_DIRECT_READ));
}
if (gimple_call_lhs (stmt))
{
if (!(flags & EAF_NOT_RETURNED_DIRECTLY))
{
struct constraint_expr cexpr;
cexpr.var = tem->id;
cexpr.type = SCALAR;
cexpr.offset = 0;
results->safe_push (cexpr);
}
if (!callarg_transitive & !(flags & EAF_NOT_RETURNED_INDIRECTLY))
{
struct constraint_expr cexpr;
cexpr.var = indir_tem->id;
cexpr.type = SCALAR;
cexpr.offset = 0;
results->safe_push (cexpr);
}
}
if (!(flags & EAF_NO_DIRECT_READ))
{
varinfo_t uses = get_call_use_vi (stmt);
make_copy_constraint (uses, tem->id);
if (!callarg_transitive & !(flags & EAF_NO_INDIRECT_READ))
make_copy_constraint (uses, indir_tem->id);
}
else
/* To read indirectly we need to read directly. */
gcc_checking_assert (flags & EAF_NO_INDIRECT_READ);
if (!(flags & EAF_NO_DIRECT_CLOBBER))
{
struct constraint_expr lhs, rhs;
/* *arg = callescape. */
lhs.type = DEREF;
lhs.var = tem->id;
lhs.offset = 0;
rhs.type = SCALAR;
rhs.var = callescape_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* callclobbered = arg. */
make_copy_constraint (get_call_clobber_vi (stmt), tem->id);
}
if (!callarg_transitive & !(flags & EAF_NO_INDIRECT_CLOBBER))
{
struct constraint_expr lhs, rhs;
/* *indir_arg = callescape. */
lhs.type = DEREF;
lhs.var = indir_tem->id;
lhs.offset = 0;
rhs.type = SCALAR;
rhs.var = callescape_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* callclobbered = indir_arg. */
make_copy_constraint (get_call_clobber_vi (stmt), indir_tem->id);
}
if (!(flags & (EAF_NO_DIRECT_ESCAPE | EAF_NO_INDIRECT_ESCAPE)))
{
struct constraint_expr lhs, rhs;
/* callescape = arg; */
lhs.var = callescape_id;
lhs.offset = 0;
lhs.type = SCALAR;
rhs.var = tem->id;
rhs.offset = 0;
rhs.type = SCALAR;
process_constraint (new_constraint (lhs, rhs));
if (writes_global_memory)
make_escape_constraint (arg);
}
else if (!callarg_transitive & !(flags & EAF_NO_INDIRECT_ESCAPE))
{
struct constraint_expr lhs, rhs;
/* callescape = *(indir_arg + UNKNOWN); */
lhs.var = callescape_id;
lhs.offset = 0;
lhs.type = SCALAR;
rhs.var = indir_tem->id;
rhs.offset = 0;
rhs.type = SCALAR;
process_constraint (new_constraint (lhs, rhs));
if (writes_global_memory)
make_indirect_escape_constraint (tem);
}
}
/* Determine global memory access of call STMT and update
WRITES_GLOBAL_MEMORY, READS_GLOBAL_MEMORY and USES_GLOBAL_MEMORY. */
static void
determine_global_memory_access (gcall *stmt,
bool *writes_global_memory,
bool *reads_global_memory,
bool *uses_global_memory)
{
tree callee;
cgraph_node *node;
modref_summary *summary;
/* We need to detrmine reads to set uses. */
gcc_assert (!uses_global_memory || reads_global_memory);
if ((callee = gimple_call_fndecl (stmt)) != NULL_TREE
&& (node = cgraph_node::get (callee)) != NULL
&& (summary = get_modref_function_summary (node)))
{
if (writes_global_memory && *writes_global_memory)
*writes_global_memory = summary->global_memory_written;
if (reads_global_memory && *reads_global_memory)
*reads_global_memory = summary->global_memory_read;
if (reads_global_memory && uses_global_memory
&& !summary->calls_interposable
&& !*reads_global_memory && node->binds_to_current_def_p ())
*uses_global_memory = false;
}
if ((writes_global_memory && *writes_global_memory)
|| (uses_global_memory && *uses_global_memory)
|| (reads_global_memory && *reads_global_memory))
{
attr_fnspec fnspec = gimple_call_fnspec (stmt);
if (fnspec.known_p ())
{
if (writes_global_memory
&& !fnspec.global_memory_written_p ())
*writes_global_memory = false;
if (reads_global_memory && !fnspec.global_memory_read_p ())
{
*reads_global_memory = false;
if (uses_global_memory)
*uses_global_memory = false;
}
}
}
}
/* For non-IPA mode, generate constraints necessary for a call on the
RHS and collect return value constraint to RESULTS to be used later in
handle_lhs_call.
IMPLICIT_EAF_FLAGS are added to each function argument. If
WRITES_GLOBAL_MEMORY is true function is assumed to possibly write to global
memory. Similar for READS_GLOBAL_MEMORY. */
static void
handle_rhs_call (gcall *stmt, vec<ce_s> *results,
int implicit_eaf_flags,
bool writes_global_memory,
bool reads_global_memory)
{
determine_global_memory_access (stmt, &writes_global_memory,
&reads_global_memory,
NULL);
varinfo_t callescape = new_var_info (NULL_TREE, "callescape", true);
/* If function can use global memory, add it to callescape
and to possible return values. If not we can still use/return addresses
of global symbols. */
struct constraint_expr lhs, rhs;
lhs.type = SCALAR;
lhs.var = callescape->id;
lhs.offset = 0;
rhs.type = reads_global_memory ? SCALAR : ADDRESSOF;
rhs.var = nonlocal_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
results->safe_push (rhs);
varinfo_t uses = get_call_use_vi (stmt);
make_copy_constraint (uses, callescape->id);
for (unsigned i = 0; i < gimple_call_num_args (stmt); ++i)
{
tree arg = gimple_call_arg (stmt, i);
int flags = gimple_call_arg_flags (stmt, i);
handle_call_arg (stmt, arg, results,
flags | implicit_eaf_flags,
callescape->id, writes_global_memory);
}
/* The static chain escapes as well. */
if (gimple_call_chain (stmt))
handle_call_arg (stmt, gimple_call_chain (stmt), results,
implicit_eaf_flags
| gimple_call_static_chain_flags (stmt),
callescape->id, writes_global_memory);
/* And if we applied NRV the address of the return slot escapes as well. */
if (gimple_call_return_slot_opt_p (stmt)
&& gimple_call_lhs (stmt) != NULL_TREE
&& TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
{
int flags = gimple_call_retslot_flags (stmt);
const int relevant_flags = EAF_NO_DIRECT_ESCAPE
| EAF_NOT_RETURNED_DIRECTLY;
if (!(flags & EAF_UNUSED) && (flags & relevant_flags) != relevant_flags)
{
auto_vec<ce_s> tmpc;
get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
if (!(flags & EAF_NO_DIRECT_ESCAPE))
{
make_constraints_to (callescape->id, tmpc);
if (writes_global_memory)
make_constraints_to (escaped_id, tmpc);
}
if (!(flags & EAF_NOT_RETURNED_DIRECTLY))
{
struct constraint_expr *c;
unsigned i;
FOR_EACH_VEC_ELT (tmpc, i, c)
results->safe_push (*c);
}
}
}
}
/* For non-IPA mode, generate constraints necessary for a call
that returns a pointer and assigns it to LHS. This simply makes
the LHS point to global and escaped variables. */
static void
handle_lhs_call (gcall *stmt, tree lhs, int flags, vec<ce_s> &rhsc,
tree fndecl)
{
auto_vec<ce_s> lhsc;
get_constraint_for (lhs, &lhsc);
/* If the store is to a global decl make sure to
add proper escape constraints. */
lhs = get_base_address (lhs);
if (lhs
&& DECL_P (lhs)
&& is_global_var (lhs))
{
struct constraint_expr tmpc;
tmpc.var = escaped_id;
tmpc.offset = 0;
tmpc.type = SCALAR;
lhsc.safe_push (tmpc);
}
/* If the call returns an argument unmodified override the rhs
constraints. */
if (flags & ERF_RETURNS_ARG
&& (flags & ERF_RETURN_ARG_MASK) < gimple_call_num_args (stmt))
{
tree arg;
rhsc.truncate (0);
arg = gimple_call_arg (stmt, flags & ERF_RETURN_ARG_MASK);
get_constraint_for (arg, &rhsc);
process_all_all_constraints (lhsc, rhsc);
rhsc.truncate (0);
}
else if (flags & ERF_NOALIAS)
{
varinfo_t vi;
struct constraint_expr tmpc;
rhsc.truncate (0);
vi = make_heapvar ("HEAP", true);
/* We are marking allocated storage local, we deal with it becoming
global by escaping and setting of vars_contains_escaped_heap. */
DECL_EXTERNAL (vi->decl) = 0;
vi->is_global_var = 0;
/* If this is not a real malloc call assume the memory was
initialized and thus may point to global memory. All
builtin functions with the malloc attribute behave in a sane way. */
if (!fndecl
|| !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
make_constraint_from (vi, nonlocal_id);
tmpc.var = vi->id;
tmpc.offset = 0;
tmpc.type = ADDRESSOF;
rhsc.safe_push (tmpc);
process_all_all_constraints (lhsc, rhsc);
rhsc.truncate (0);
}
else
process_all_all_constraints (lhsc, rhsc);
}
/* Return the varinfo for the callee of CALL. */
static varinfo_t
get_fi_for_callee (gcall *call)
{
tree decl, fn = gimple_call_fn (call);
if (fn && TREE_CODE (fn) == OBJ_TYPE_REF)
fn = OBJ_TYPE_REF_EXPR (fn);
/* If we can directly resolve the function being called, do so.
Otherwise, it must be some sort of indirect expression that
we should still be able to handle. */
decl = gimple_call_addr_fndecl (fn);
if (decl)
return get_vi_for_tree (decl);
/* If the function is anything other than a SSA name pointer we have no
clue and should be getting ANYFN (well, ANYTHING for now). */
if (!fn || TREE_CODE (fn) != SSA_NAME)
return get_varinfo (anything_id);
if (SSA_NAME_IS_DEFAULT_DEF (fn)
&& (TREE_CODE (SSA_NAME_VAR (fn)) == PARM_DECL
|| TREE_CODE (SSA_NAME_VAR (fn)) == RESULT_DECL))
fn = SSA_NAME_VAR (fn);
return get_vi_for_tree (fn);
}
/* Create constraints for assigning call argument ARG to the incoming parameter
INDEX of function FI. */
static void
find_func_aliases_for_call_arg (varinfo_t fi, unsigned index, tree arg)
{
struct constraint_expr lhs;
lhs = get_function_part_constraint (fi, fi_parm_base + index);
auto_vec<ce_s, 2> rhsc;
get_constraint_for_rhs (arg, &rhsc);
unsigned j;
struct constraint_expr *rhsp;
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
}
/* Return true if FNDECL may be part of another lto partition. */
static bool
fndecl_maybe_in_other_partition (tree fndecl)
{
cgraph_node *fn_node = cgraph_node::get (fndecl);
if (fn_node == NULL)
return true;
return fn_node->in_other_partition;
}
/* Create constraints for the builtin call T. Return true if the call
was handled, otherwise false. */
static bool
find_func_aliases_for_builtin_call (struct function *fn, gcall *t)
{
tree fndecl = gimple_call_fndecl (t);
auto_vec<ce_s, 2> lhsc;
auto_vec<ce_s, 4> rhsc;
varinfo_t fi;
if (gimple_call_builtin_p (t, BUILT_IN_NORMAL))
/* ??? All builtins that are handled here need to be handled
in the alias-oracle query functions explicitly! */
switch (DECL_FUNCTION_CODE (fndecl))
{
/* All the following functions return a pointer to the same object
as their first argument points to. The functions do not add
to the ESCAPED solution. The functions make the first argument
pointed to memory point to what the second argument pointed to
memory points to. */
case BUILT_IN_STRCPY:
case BUILT_IN_STRNCPY:
case BUILT_IN_BCOPY:
case BUILT_IN_MEMCPY:
case BUILT_IN_MEMMOVE:
case BUILT_IN_MEMPCPY:
case BUILT_IN_STPCPY:
case BUILT_IN_STPNCPY:
case BUILT_IN_STRCAT:
case BUILT_IN_STRNCAT:
case BUILT_IN_STRCPY_CHK:
case BUILT_IN_STRNCPY_CHK:
case BUILT_IN_MEMCPY_CHK:
case BUILT_IN_MEMMOVE_CHK:
case BUILT_IN_MEMPCPY_CHK:
case BUILT_IN_STPCPY_CHK:
case BUILT_IN_STPNCPY_CHK:
case BUILT_IN_STRCAT_CHK:
case BUILT_IN_STRNCAT_CHK:
case BUILT_IN_TM_MEMCPY:
case BUILT_IN_TM_MEMMOVE:
{
tree res = gimple_call_lhs (t);
tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
== BUILT_IN_BCOPY ? 1 : 0));
tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (fndecl)
== BUILT_IN_BCOPY ? 0 : 1));
if (res != NULL_TREE)
{
get_constraint_for (res, &lhsc);
if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPNCPY
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY_CHK
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPCPY_CHK
|| DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STPNCPY_CHK)
get_constraint_for_ptr_offset (dest, NULL_TREE, &rhsc);
else
get_constraint_for (dest, &rhsc);
process_all_all_constraints (lhsc, rhsc);
lhsc.truncate (0);
rhsc.truncate (0);
}
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
do_deref (&lhsc);
do_deref (&rhsc);
process_all_all_constraints (lhsc, rhsc);
return true;
}
case BUILT_IN_MEMSET:
case BUILT_IN_MEMSET_CHK:
case BUILT_IN_TM_MEMSET:
{
tree res = gimple_call_lhs (t);
tree dest = gimple_call_arg (t, 0);
unsigned i;
ce_s *lhsp;
struct constraint_expr ac;
if (res != NULL_TREE)
{
get_constraint_for (res, &lhsc);
get_constraint_for (dest, &rhsc);
process_all_all_constraints (lhsc, rhsc);
lhsc.truncate (0);
}
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
do_deref (&lhsc);
if (flag_delete_null_pointer_checks
&& integer_zerop (gimple_call_arg (t, 1)))
{
ac.type = ADDRESSOF;
ac.var = nothing_id;
}
else
{
ac.type = SCALAR;
ac.var = integer_id;
}
ac.offset = 0;
FOR_EACH_VEC_ELT (lhsc, i, lhsp)
process_constraint (new_constraint (*lhsp, ac));
return true;
}
case BUILT_IN_STACK_SAVE:
case BUILT_IN_STACK_RESTORE:
/* Nothing interesting happens. */
return true;
case BUILT_IN_ALLOCA:
case BUILT_IN_ALLOCA_WITH_ALIGN:
case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX:
{
tree ptr = gimple_call_lhs (t);
if (ptr == NULL_TREE)
return true;
get_constraint_for (ptr, &lhsc);
varinfo_t vi = make_heapvar ("HEAP", true);
/* Alloca storage is never global. To exempt it from escaped
handling make it a non-heap var. */
DECL_EXTERNAL (vi->decl) = 0;
vi->is_global_var = 0;
vi->is_heap_var = 0;
struct constraint_expr tmpc;
tmpc.var = vi->id;
tmpc.offset = 0;
tmpc.type = ADDRESSOF;
rhsc.safe_push (tmpc);
process_all_all_constraints (lhsc, rhsc);
return true;
}
case BUILT_IN_POSIX_MEMALIGN:
{
tree ptrptr = gimple_call_arg (t, 0);
get_constraint_for (ptrptr, &lhsc);
do_deref (&lhsc);
varinfo_t vi = make_heapvar ("HEAP", true);
/* We are marking allocated storage local, we deal with it becoming
global by escaping and setting of vars_contains_escaped_heap. */
DECL_EXTERNAL (vi->decl) = 0;
vi->is_global_var = 0;
struct constraint_expr tmpc;
tmpc.var = vi->id;
tmpc.offset = 0;
tmpc.type = ADDRESSOF;
rhsc.safe_push (tmpc);
process_all_all_constraints (lhsc, rhsc);
return true;
}
case BUILT_IN_ASSUME_ALIGNED:
{
tree res = gimple_call_lhs (t);
tree dest = gimple_call_arg (t, 0);
if (res != NULL_TREE)
{
get_constraint_for (res, &lhsc);
get_constraint_for (dest, &rhsc);
process_all_all_constraints (lhsc, rhsc);
}
return true;
}
/* All the following functions do not return pointers, do not
modify the points-to sets of memory reachable from their
arguments and do not add to the ESCAPED solution. */
case BUILT_IN_SINCOS:
case BUILT_IN_SINCOSF:
case BUILT_IN_SINCOSL:
case BUILT_IN_FREXP:
case BUILT_IN_FREXPF:
case BUILT_IN_FREXPL:
case BUILT_IN_GAMMA_R:
case BUILT_IN_GAMMAF_R:
case BUILT_IN_GAMMAL_R:
case BUILT_IN_LGAMMA_R:
case BUILT_IN_LGAMMAF_R:
case BUILT_IN_LGAMMAL_R:
case BUILT_IN_MODF:
case BUILT_IN_MODFF:
case BUILT_IN_MODFL:
case BUILT_IN_REMQUO:
case BUILT_IN_REMQUOF:
case BUILT_IN_REMQUOL:
case BUILT_IN_FREE:
return true;
case BUILT_IN_STRDUP:
case BUILT_IN_STRNDUP:
case BUILT_IN_REALLOC:
if (gimple_call_lhs (t))
{
auto_vec<ce_s> rhsc;
handle_lhs_call (t, gimple_call_lhs (t),
gimple_call_return_flags (t) | ERF_NOALIAS,
rhsc, fndecl);
get_constraint_for_ptr_offset (gimple_call_lhs (t),
NULL_TREE, &lhsc);
get_constraint_for_ptr_offset (gimple_call_arg (t, 0),
NULL_TREE, &rhsc);
do_deref (&lhsc);
do_deref (&rhsc);
process_all_all_constraints (lhsc, rhsc);
lhsc.truncate (0);
rhsc.truncate (0);
/* For realloc the resulting pointer can be equal to the
argument as well. But only doing this wouldn't be
correct because with ptr == 0 realloc behaves like malloc. */
if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_REALLOC)
{
get_constraint_for (gimple_call_lhs (t), &lhsc);
get_constraint_for (gimple_call_arg (t, 0), &rhsc);
process_all_all_constraints (lhsc, rhsc);
}
return true;
}
break;
/* String / character search functions return a pointer into the
source string or NULL. */
case BUILT_IN_INDEX:
case BUILT_IN_STRCHR:
case BUILT_IN_STRRCHR:
case BUILT_IN_MEMCHR:
case BUILT_IN_STRSTR:
case BUILT_IN_STRPBRK:
if (gimple_call_lhs (t))
{
tree src = gimple_call_arg (t, 0);
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
constraint_expr nul;
nul.var = nothing_id;
nul.offset = 0;
nul.type = ADDRESSOF;
rhsc.safe_push (nul);
get_constraint_for (gimple_call_lhs (t), &lhsc);
process_all_all_constraints (lhsc, rhsc);
}
return true;
/* Pure functions that return something not based on any object and
that use the memory pointed to by their arguments (but not
transitively). */
case BUILT_IN_STRCMP:
case BUILT_IN_STRCMP_EQ:
case BUILT_IN_STRNCMP:
case BUILT_IN_STRNCMP_EQ:
case BUILT_IN_STRCASECMP:
case BUILT_IN_STRNCASECMP:
case BUILT_IN_MEMCMP:
case BUILT_IN_BCMP:
case BUILT_IN_STRSPN:
case BUILT_IN_STRCSPN:
{
varinfo_t uses = get_call_use_vi (t);
make_any_offset_constraints (uses);
make_constraint_to (uses->id, gimple_call_arg (t, 0));
make_constraint_to (uses->id, gimple_call_arg (t, 1));
/* No constraints are necessary for the return value. */
return true;
}
case BUILT_IN_STRLEN:
{
varinfo_t uses = get_call_use_vi (t);
make_any_offset_constraints (uses);
make_constraint_to (uses->id, gimple_call_arg (t, 0));
/* No constraints are necessary for the return value. */
return true;
}
case BUILT_IN_OBJECT_SIZE:
case BUILT_IN_CONSTANT_P:
{
/* No constraints are necessary for the return value or the
arguments. */
return true;
}
/* Trampolines are special - they set up passing the static
frame. */
case BUILT_IN_INIT_TRAMPOLINE:
{
tree tramp = gimple_call_arg (t, 0);
tree nfunc = gimple_call_arg (t, 1);
tree frame = gimple_call_arg (t, 2);
unsigned i;
struct constraint_expr lhs, *rhsp;
if (in_ipa_mode)
{
varinfo_t nfi = NULL;
gcc_assert (TREE_CODE (nfunc) == ADDR_EXPR);
nfi = lookup_vi_for_tree (TREE_OPERAND (nfunc, 0));
if (nfi)
{
lhs = get_function_part_constraint (nfi, fi_static_chain);
get_constraint_for (frame, &rhsc);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
/* Make the frame point to the function for
the trampoline adjustment call. */
get_constraint_for (tramp, &lhsc);
do_deref (&lhsc);
get_constraint_for (nfunc, &rhsc);
process_all_all_constraints (lhsc, rhsc);
return true;
}
}
/* Else fallthru to generic handling which will let
the frame escape. */
break;
}
case BUILT_IN_ADJUST_TRAMPOLINE:
{
tree tramp = gimple_call_arg (t, 0);
tree res = gimple_call_lhs (t);
if (in_ipa_mode && res)
{
get_constraint_for (res, &lhsc);
get_constraint_for (tramp, &rhsc);
do_deref (&rhsc);
process_all_all_constraints (lhsc, rhsc);
}
return true;
}
CASE_BUILT_IN_TM_STORE (1):
CASE_BUILT_IN_TM_STORE (2):
CASE_BUILT_IN_TM_STORE (4):
CASE_BUILT_IN_TM_STORE (8):
CASE_BUILT_IN_TM_STORE (FLOAT):
CASE_BUILT_IN_TM_STORE (DOUBLE):
CASE_BUILT_IN_TM_STORE (LDOUBLE):
CASE_BUILT_IN_TM_STORE (M64):
CASE_BUILT_IN_TM_STORE (M128):
CASE_BUILT_IN_TM_STORE (M256):
{
tree addr = gimple_call_arg (t, 0);
tree src = gimple_call_arg (t, 1);
get_constraint_for (addr, &lhsc);
do_deref (&lhsc);
get_constraint_for (src, &rhsc);
process_all_all_constraints (lhsc, rhsc);
return true;
}
CASE_BUILT_IN_TM_LOAD (1):
CASE_BUILT_IN_TM_LOAD (2):
CASE_BUILT_IN_TM_LOAD (4):
CASE_BUILT_IN_TM_LOAD (8):
CASE_BUILT_IN_TM_LOAD (FLOAT):
CASE_BUILT_IN_TM_LOAD (DOUBLE):
CASE_BUILT_IN_TM_LOAD (LDOUBLE):
CASE_BUILT_IN_TM_LOAD (M64):
CASE_BUILT_IN_TM_LOAD (M128):
CASE_BUILT_IN_TM_LOAD (M256):
{
tree dest = gimple_call_lhs (t);
tree addr = gimple_call_arg (t, 0);
get_constraint_for (dest, &lhsc);
get_constraint_for (addr, &rhsc);
do_deref (&rhsc);
process_all_all_constraints (lhsc, rhsc);
return true;
}
/* Variadic argument handling needs to be handled in IPA
mode as well. */
case BUILT_IN_VA_START:
{
tree valist = gimple_call_arg (t, 0);
struct constraint_expr rhs, *lhsp;
unsigned i;
get_constraint_for_ptr_offset (valist, NULL_TREE, &lhsc);
do_deref (&lhsc);
/* The va_list gets access to pointers in variadic
arguments. Which we know in the case of IPA analysis
and otherwise are just all nonlocal variables. */
if (in_ipa_mode)
{
fi = lookup_vi_for_tree (fn->decl);
rhs = get_function_part_constraint (fi, ~0);
rhs.type = ADDRESSOF;
}
else
{
rhs.var = nonlocal_id;
rhs.type = ADDRESSOF;
rhs.offset = 0;
}
FOR_EACH_VEC_ELT (lhsc, i, lhsp)
process_constraint (new_constraint (*lhsp, rhs));
/* va_list is clobbered. */
make_constraint_to (get_call_clobber_vi (t)->id, valist);
return true;
}
/* va_end doesn't have any effect that matters. */
case BUILT_IN_VA_END:
return true;
/* Alternate return. Simply give up for now. */
case BUILT_IN_RETURN:
{
fi = NULL;
if (!in_ipa_mode
|| !(fi = get_vi_for_tree (fn->decl)))
make_constraint_from (get_varinfo (escaped_id), anything_id);
else if (in_ipa_mode
&& fi != NULL)
{
struct constraint_expr lhs, rhs;
lhs = get_function_part_constraint (fi, fi_result);
rhs.var = anything_id;
rhs.offset = 0;
rhs.type = SCALAR;
process_constraint (new_constraint (lhs, rhs));
}
return true;
}
case BUILT_IN_GOMP_PARALLEL:
case BUILT_IN_GOACC_PARALLEL:
{
if (in_ipa_mode)
{
unsigned int fnpos, argpos;
switch (DECL_FUNCTION_CODE (fndecl))
{
case BUILT_IN_GOMP_PARALLEL:
/* __builtin_GOMP_parallel (fn, data, num_threads, flags). */
fnpos = 0;
argpos = 1;
break;
case BUILT_IN_GOACC_PARALLEL:
/* __builtin_GOACC_parallel (flags_m, fn, mapnum, hostaddrs,
sizes, kinds, ...). */
fnpos = 1;
argpos = 3;
break;
default:
gcc_unreachable ();
}
tree fnarg = gimple_call_arg (t, fnpos);
gcc_assert (TREE_CODE (fnarg) == ADDR_EXPR);
tree fndecl = TREE_OPERAND (fnarg, 0);
if (fndecl_maybe_in_other_partition (fndecl))
/* Fallthru to general call handling. */
break;
tree arg = gimple_call_arg (t, argpos);
varinfo_t fi = get_vi_for_tree (fndecl);
find_func_aliases_for_call_arg (fi, 0, arg);
return true;
}
/* Else fallthru to generic call handling. */
break;
}
/* printf-style functions may have hooks to set pointers to
point to somewhere into the generated string. Leave them
for a later exercise... */
default:
/* Fallthru to general call handling. */;
}
return false;
}
/* Create constraints for the call T. */
static void
find_func_aliases_for_call (struct function *fn, gcall *t)
{
tree fndecl = gimple_call_fndecl (t);
varinfo_t fi;
if (fndecl != NULL_TREE
&& fndecl_built_in_p (fndecl)
&& find_func_aliases_for_builtin_call (fn, t))
return;
if (gimple_call_internal_p (t, IFN_DEFERRED_INIT))
return;
fi = get_fi_for_callee (t);
if (!in_ipa_mode
|| (fi->decl && fndecl && !fi->is_fn_info))
{
auto_vec<ce_s, 16> rhsc;
int flags = gimple_call_flags (t);
/* Const functions can return their arguments and addresses
of global memory but not of escaped memory. */
if (flags & (ECF_CONST|ECF_NOVOPS))
{
if (gimple_call_lhs (t))
handle_rhs_call (t, &rhsc, implicit_const_eaf_flags, false, false);
}
/* Pure functions can return addresses in and of memory
reachable from their arguments, but they are not an escape
point for reachable memory of their arguments. */
else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
handle_rhs_call (t, &rhsc, implicit_pure_eaf_flags, false, true);
/* If the call is to a replaceable operator delete and results
from a delete expression as opposed to a direct call to
such operator, then the effects for PTA (in particular
the escaping of the pointer) can be ignored. */
else if (fndecl
&& DECL_IS_OPERATOR_DELETE_P (fndecl)
&& gimple_call_from_new_or_delete (t))
;
else
handle_rhs_call (t, &rhsc, 0, true, true);
if (gimple_call_lhs (t))
handle_lhs_call (t, gimple_call_lhs (t),
gimple_call_return_flags (t), rhsc, fndecl);
}
else
{
auto_vec<ce_s, 2> rhsc;
tree lhsop;
unsigned j;
/* Assign all the passed arguments to the appropriate incoming
parameters of the function. */
for (j = 0; j < gimple_call_num_args (t); j++)
{
tree arg = gimple_call_arg (t, j);
find_func_aliases_for_call_arg (fi, j, arg);
}
/* If we are returning a value, assign it to the result. */
lhsop = gimple_call_lhs (t);
if (lhsop)
{
auto_vec<ce_s, 2> lhsc;
struct constraint_expr rhs;
struct constraint_expr *lhsp;
bool aggr_p = aggregate_value_p (lhsop, gimple_call_fntype (t));
get_constraint_for (lhsop, &lhsc);
rhs = get_function_part_constraint (fi, fi_result);
if (aggr_p)
{
auto_vec<ce_s, 2> tem;
tem.quick_push (rhs);
do_deref (&tem);
gcc_checking_assert (tem.length () == 1);
rhs = tem[0];
}
FOR_EACH_VEC_ELT (lhsc, j, lhsp)
process_constraint (new_constraint (*lhsp, rhs));
/* If we pass the result decl by reference, honor that. */
if (aggr_p)
{
struct constraint_expr lhs;
struct constraint_expr *rhsp;
get_constraint_for_address_of (lhsop, &rhsc);
lhs = get_function_part_constraint (fi, fi_result);
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
}
}
/* If we use a static chain, pass it along. */
if (gimple_call_chain (t))
{
struct constraint_expr lhs;
struct constraint_expr *rhsp;
get_constraint_for (gimple_call_chain (t), &rhsc);
lhs = get_function_part_constraint (fi, fi_static_chain);
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
}
}
}
/* Walk statement T setting up aliasing constraints according to the
references found in T. This function is the main part of the
constraint builder. AI points to auxiliary alias information used
when building alias sets and computing alias grouping heuristics. */
static void
find_func_aliases (struct function *fn, gimple *origt)
{
gimple *t = origt;
auto_vec<ce_s, 16> lhsc;
auto_vec<ce_s, 16> rhsc;
varinfo_t fi;
/* Now build constraints expressions. */
if (gimple_code (t) == GIMPLE_PHI)
{
/* For a phi node, assign all the arguments to
the result. */
get_constraint_for (gimple_phi_result (t), &lhsc);
for (unsigned i = 0; i < gimple_phi_num_args (t); i++)
{
get_constraint_for_rhs (gimple_phi_arg_def (t, i), &rhsc);
process_all_all_constraints (lhsc, rhsc);
rhsc.truncate (0);
}
}
/* In IPA mode, we need to generate constraints to pass call
arguments through their calls. There are two cases,
either a GIMPLE_CALL returning a value, or just a plain
GIMPLE_CALL when we are not.
In non-ipa mode, we need to generate constraints for each
pointer passed by address. */
else if (is_gimple_call (t))
find_func_aliases_for_call (fn, as_a <gcall *> (t));
/* Otherwise, just a regular assignment statement. Only care about
operations with pointer result, others are dealt with as escape
points if they have pointer operands. */
else if (is_gimple_assign (t))
{
/* Otherwise, just a regular assignment statement. */
tree lhsop = gimple_assign_lhs (t);
tree rhsop = (gimple_num_ops (t) == 2) ? gimple_assign_rhs1 (t) : NULL;
if (rhsop && TREE_CLOBBER_P (rhsop))
/* Ignore clobbers, they don't actually store anything into
the LHS. */
;
else if (rhsop && AGGREGATE_TYPE_P (TREE_TYPE (lhsop)))
do_structure_copy (lhsop, rhsop);
else
{
enum tree_code code = gimple_assign_rhs_code (t);
get_constraint_for (lhsop, &lhsc);
if (code == POINTER_PLUS_EXPR)
get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
gimple_assign_rhs2 (t), &rhsc);
else if (code == POINTER_DIFF_EXPR)
/* The result is not a pointer (part). */
;
else if (code == BIT_AND_EXPR
&& TREE_CODE (gimple_assign_rhs2 (t)) == INTEGER_CST)
{
/* Aligning a pointer via a BIT_AND_EXPR is offsetting
the pointer. Handle it by offsetting it by UNKNOWN. */
get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
NULL_TREE, &rhsc);
}
else if (code == TRUNC_DIV_EXPR
|| code == CEIL_DIV_EXPR
|| code == FLOOR_DIV_EXPR
|| code == ROUND_DIV_EXPR
|| code == EXACT_DIV_EXPR
|| code == TRUNC_MOD_EXPR
|| code == CEIL_MOD_EXPR
|| code == FLOOR_MOD_EXPR
|| code == ROUND_MOD_EXPR)
/* Division and modulo transfer the pointer from the LHS. */
get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
NULL_TREE, &rhsc);
else if (CONVERT_EXPR_CODE_P (code)
|| gimple_assign_single_p (t))
/* See through conversions, single RHS are handled by
get_constraint_for_rhs. */
get_constraint_for_rhs (rhsop, &rhsc);
else if (code == COND_EXPR)
{
/* The result is a merge of both COND_EXPR arms. */
auto_vec<ce_s, 2> tmp;
struct constraint_expr *rhsp;
unsigned i;
get_constraint_for_rhs (gimple_assign_rhs2 (t), &rhsc);
get_constraint_for_rhs (gimple_assign_rhs3 (t), &tmp);
FOR_EACH_VEC_ELT (tmp, i, rhsp)
rhsc.safe_push (*rhsp);
}
else if (truth_value_p (code))
/* Truth value results are not pointer (parts). Or at least
very unreasonable obfuscation of a part. */
;
else
{
/* All other operations are possibly offsetting merges. */
auto_vec<ce_s, 4> tmp;
struct constraint_expr *rhsp;
unsigned i, j;
get_constraint_for_ptr_offset (gimple_assign_rhs1 (t),
NULL_TREE, &rhsc);
for (i = 2; i < gimple_num_ops (t); ++i)
{
get_constraint_for_ptr_offset (gimple_op (t, i),
NULL_TREE, &tmp);
FOR_EACH_VEC_ELT (tmp, j, rhsp)
rhsc.safe_push (*rhsp);
tmp.truncate (0);
}
}
process_all_all_constraints (lhsc, rhsc);
}
/* If there is a store to a global variable the rhs escapes. */
if ((lhsop = get_base_address (lhsop)) != NULL_TREE
&& DECL_P (lhsop))
{
varinfo_t vi = get_vi_for_tree (lhsop);
if ((! in_ipa_mode && vi->is_global_var)
|| vi->is_ipa_escape_point)
make_escape_constraint (rhsop);
}
}
/* Handle escapes through return. */
else if (gimple_code (t) == GIMPLE_RETURN
&& gimple_return_retval (as_a <greturn *> (t)) != NULL_TREE)
{
greturn *return_stmt = as_a <greturn *> (t);
tree retval = gimple_return_retval (return_stmt);
if (!in_ipa_mode)
make_constraint_to (escaped_return_id, retval);
else
{
struct constraint_expr lhs ;
struct constraint_expr *rhsp;
unsigned i;
fi = lookup_vi_for_tree (fn->decl);
lhs = get_function_part_constraint (fi, fi_result);
get_constraint_for_rhs (retval, &rhsc);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
}
}
/* Handle asms conservatively by adding escape constraints to everything. */
else if (gasm *asm_stmt = dyn_cast <gasm *> (t))
{
unsigned i, noutputs;
const char **oconstraints;
const char *constraint;
bool allows_mem, allows_reg, is_inout;
noutputs = gimple_asm_noutputs (asm_stmt);
oconstraints = XALLOCAVEC (const char *, noutputs);
for (i = 0; i < noutputs; ++i)
{
tree link = gimple_asm_output_op (asm_stmt, i);
tree op = TREE_VALUE (link);
constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
oconstraints[i] = constraint;
parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
&allows_reg, &is_inout, nullptr);
/* A memory constraint makes the address of the operand escape. */
if (!allows_reg && allows_mem)
{
auto_vec<ce_s> tmpc;
get_constraint_for_address_of (op, &tmpc);
make_constraints_to (escaped_id, tmpc);
}
/* The asm may read global memory, so outputs may point to
any global memory. */
if (op)
{
auto_vec<ce_s, 2> lhsc;
struct constraint_expr rhsc, *lhsp;
unsigned j;
get_constraint_for (op, &lhsc);
rhsc.var = nonlocal_id;
rhsc.offset = 0;
rhsc.type = SCALAR;
FOR_EACH_VEC_ELT (lhsc, j, lhsp)
process_constraint (new_constraint (*lhsp, rhsc));
}
}
for (i = 0; i < gimple_asm_ninputs (asm_stmt); ++i)
{
tree link = gimple_asm_input_op (asm_stmt, i);
tree op = TREE_VALUE (link);
constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints,
&allows_mem, &allows_reg, nullptr);
/* A memory constraint makes the address of the operand escape. */
if (!allows_reg && allows_mem)
{
auto_vec<ce_s> tmpc;
get_constraint_for_address_of (op, &tmpc);
make_constraints_to (escaped_id, tmpc);
}
/* Strictly we'd only need the constraint to ESCAPED if
the asm clobbers memory, otherwise using something
along the lines of per-call clobbers/uses would be enough. */
else if (op)
make_escape_constraint (op);
}
}
}
/* Create a constraint adding to the clobber set of FI the memory
pointed to by PTR. */
static void
process_ipa_clobber (varinfo_t fi, tree ptr)
{
vec<ce_s> ptrc = vNULL;
struct constraint_expr *c, lhs;
unsigned i;
get_constraint_for_rhs (ptr, &ptrc);
lhs = get_function_part_constraint (fi, fi_clobbers);
FOR_EACH_VEC_ELT (ptrc, i, c)
process_constraint (new_constraint (lhs, *c));
ptrc.release ();
}
/* Walk statement T setting up clobber and use constraints according to the
references found in T. This function is a main part of the
IPA constraint builder. */
static void
find_func_clobbers (struct function *fn, gimple *origt)
{
gimple *t = origt;
auto_vec<ce_s, 16> lhsc;
auto_vec<ce_s, 16> rhsc;
varinfo_t fi;
/* Add constraints for clobbered/used in IPA mode.
We are not interested in what automatic variables are clobbered
or used as we only use the information in the caller to which
they do not escape. */
gcc_assert (in_ipa_mode);
/* If the stmt refers to memory in any way it better had a VUSE. */
if (gimple_vuse (t) == NULL_TREE)
return;
/* We'd better have function information for the current function. */
fi = lookup_vi_for_tree (fn->decl);
gcc_assert (fi != NULL);
/* Account for stores in assignments and calls. */
if (gimple_vdef (t) != NULL_TREE
&& gimple_has_lhs (t))
{
tree lhs = gimple_get_lhs (t);
tree tem = lhs;
while (handled_component_p (tem))
tem = TREE_OPERAND (tem, 0);
if ((DECL_P (tem)
&& !auto_var_in_fn_p (tem, fn->decl))
|| INDIRECT_REF_P (tem)
|| (TREE_CODE (tem) == MEM_REF
&& !(TREE_CODE (TREE_OPERAND (tem, 0)) == ADDR_EXPR
&& auto_var_in_fn_p
(TREE_OPERAND (TREE_OPERAND (tem, 0), 0), fn->decl))))
{
struct constraint_expr lhsc, *rhsp;
unsigned i;
lhsc = get_function_part_constraint (fi, fi_clobbers);
get_constraint_for_address_of (lhs, &rhsc);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhsc, *rhsp));
rhsc.truncate (0);
}
}
/* Account for uses in assigments and returns. */
if (gimple_assign_single_p (t)
|| (gimple_code (t) == GIMPLE_RETURN
&& gimple_return_retval (as_a <greturn *> (t)) != NULL_TREE))
{
tree rhs = (gimple_assign_single_p (t)
? gimple_assign_rhs1 (t)
: gimple_return_retval (as_a <greturn *> (t)));
tree tem = rhs;
while (handled_component_p (tem))
tem = TREE_OPERAND (tem, 0);
if ((DECL_P (tem)
&& !auto_var_in_fn_p (tem, fn->decl))
|| INDIRECT_REF_P (tem)
|| (TREE_CODE (tem) == MEM_REF
&& !(TREE_CODE (TREE_OPERAND (tem, 0)) == ADDR_EXPR
&& auto_var_in_fn_p
(TREE_OPERAND (TREE_OPERAND (tem, 0), 0), fn->decl))))
{
struct constraint_expr lhs, *rhsp;
unsigned i;
lhs = get_function_part_constraint (fi, fi_uses);
get_constraint_for_address_of (rhs, &rhsc);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
}
}
if (gcall *call_stmt = dyn_cast <gcall *> (t))
{
varinfo_t cfi = NULL;
tree decl = gimple_call_fndecl (t);
struct constraint_expr lhs, rhs;
unsigned i, j;
/* For builtins we do not have separate function info. For those
we do not generate escapes for we have to generate clobbers/uses. */
if (gimple_call_builtin_p (t, BUILT_IN_NORMAL))
switch (DECL_FUNCTION_CODE (decl))
{
/* The following functions use and clobber memory pointed to
by their arguments. */
case BUILT_IN_STRCPY:
case BUILT_IN_STRNCPY:
case BUILT_IN_BCOPY:
case BUILT_IN_MEMCPY:
case BUILT_IN_MEMMOVE:
case BUILT_IN_MEMPCPY:
case BUILT_IN_STPCPY:
case BUILT_IN_STPNCPY:
case BUILT_IN_STRCAT:
case BUILT_IN_STRNCAT:
case BUILT_IN_STRCPY_CHK:
case BUILT_IN_STRNCPY_CHK:
case BUILT_IN_MEMCPY_CHK:
case BUILT_IN_MEMMOVE_CHK:
case BUILT_IN_MEMPCPY_CHK:
case BUILT_IN_STPCPY_CHK:
case BUILT_IN_STPNCPY_CHK:
case BUILT_IN_STRCAT_CHK:
case BUILT_IN_STRNCAT_CHK:
{
tree dest = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
== BUILT_IN_BCOPY ? 1 : 0));
tree src = gimple_call_arg (t, (DECL_FUNCTION_CODE (decl)
== BUILT_IN_BCOPY ? 0 : 1));
unsigned i;
struct constraint_expr *rhsp, *lhsp;
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
lhs = get_function_part_constraint (fi, fi_clobbers);
FOR_EACH_VEC_ELT (lhsc, i, lhsp)
process_constraint (new_constraint (lhs, *lhsp));
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
lhs = get_function_part_constraint (fi, fi_uses);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
return;
}
/* The following function clobbers memory pointed to by
its argument. */
case BUILT_IN_MEMSET:
case BUILT_IN_MEMSET_CHK:
case BUILT_IN_POSIX_MEMALIGN:
{
tree dest = gimple_call_arg (t, 0);
unsigned i;
ce_s *lhsp;
get_constraint_for_ptr_offset (dest, NULL_TREE, &lhsc);
lhs = get_function_part_constraint (fi, fi_clobbers);
FOR_EACH_VEC_ELT (lhsc, i, lhsp)
process_constraint (new_constraint (lhs, *lhsp));
return;
}
/* The following functions clobber their second and third
arguments. */
case BUILT_IN_SINCOS:
case BUILT_IN_SINCOSF:
case BUILT_IN_SINCOSL:
{
process_ipa_clobber (fi, gimple_call_arg (t, 1));
process_ipa_clobber (fi, gimple_call_arg (t, 2));
return;
}
/* The following functions clobber their second argument. */
case BUILT_IN_FREXP:
case BUILT_IN_FREXPF:
case BUILT_IN_FREXPL:
case BUILT_IN_LGAMMA_R:
case BUILT_IN_LGAMMAF_R:
case BUILT_IN_LGAMMAL_R:
case BUILT_IN_GAMMA_R:
case BUILT_IN_GAMMAF_R:
case BUILT_IN_GAMMAL_R:
case BUILT_IN_MODF:
case BUILT_IN_MODFF:
case BUILT_IN_MODFL:
{
process_ipa_clobber (fi, gimple_call_arg (t, 1));
return;
}
/* The following functions clobber their third argument. */
case BUILT_IN_REMQUO:
case BUILT_IN_REMQUOF:
case BUILT_IN_REMQUOL:
{
process_ipa_clobber (fi, gimple_call_arg (t, 2));
return;
}
/* The following functions use what their first argument
points to. */
case BUILT_IN_STRDUP:
case BUILT_IN_STRNDUP:
case BUILT_IN_REALLOC:
case BUILT_IN_INDEX:
case BUILT_IN_STRCHR:
case BUILT_IN_STRRCHR:
case BUILT_IN_MEMCHR:
{
tree src = gimple_call_arg (t, 0);
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
lhs = get_function_part_constraint (fi, fi_uses);
struct constraint_expr *rhsp;
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
return;
}
/* The following functions use what their first and second argument
point to. */
case BUILT_IN_STRSTR:
case BUILT_IN_STRPBRK:
{
tree src = gimple_call_arg (t, 0);
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
lhs = get_function_part_constraint (fi, fi_uses);
struct constraint_expr *rhsp;
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
src = gimple_call_arg (t, 1);
get_constraint_for_ptr_offset (src, NULL_TREE, &rhsc);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
return;
}
/* The following functions neither read nor clobber memory. */
case BUILT_IN_ASSUME_ALIGNED:
case BUILT_IN_FREE:
return;
/* Trampolines are of no interest to us. */
case BUILT_IN_INIT_TRAMPOLINE:
case BUILT_IN_ADJUST_TRAMPOLINE:
return;
case BUILT_IN_VA_START:
case BUILT_IN_VA_END:
return;
case BUILT_IN_GOMP_PARALLEL:
case BUILT_IN_GOACC_PARALLEL:
{
unsigned int fnpos, argpos;
unsigned int implicit_use_args[2];
unsigned int num_implicit_use_args = 0;
switch (DECL_FUNCTION_CODE (decl))
{
case BUILT_IN_GOMP_PARALLEL:
/* __builtin_GOMP_parallel (fn, data, num_threads, flags). */
fnpos = 0;
argpos = 1;
break;
case BUILT_IN_GOACC_PARALLEL:
/* __builtin_GOACC_parallel (flags_m, fn, mapnum, hostaddrs,
sizes, kinds, ...). */
fnpos = 1;
argpos = 3;
implicit_use_args[num_implicit_use_args++] = 4;
implicit_use_args[num_implicit_use_args++] = 5;
break;
default:
gcc_unreachable ();
}
tree fnarg = gimple_call_arg (t, fnpos);
gcc_assert (TREE_CODE (fnarg) == ADDR_EXPR);
tree fndecl = TREE_OPERAND (fnarg, 0);
if (fndecl_maybe_in_other_partition (fndecl))
/* Fallthru to general call handling. */
break;
varinfo_t cfi = get_vi_for_tree (fndecl);
tree arg = gimple_call_arg (t, argpos);
/* Parameter passed by value is used. */
lhs = get_function_part_constraint (fi, fi_uses);
struct constraint_expr *rhsp;
get_constraint_for (arg, &rhsc);
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
/* Handle parameters used by the call, but not used in cfi, as
implicitly used by cfi. */
lhs = get_function_part_constraint (cfi, fi_uses);
for (unsigned i = 0; i < num_implicit_use_args; ++i)
{
tree arg = gimple_call_arg (t, implicit_use_args[i]);
get_constraint_for (arg, &rhsc);
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
}
/* The caller clobbers what the callee does. */
lhs = get_function_part_constraint (fi, fi_clobbers);
rhs = get_function_part_constraint (cfi, fi_clobbers);
process_constraint (new_constraint (lhs, rhs));
/* The caller uses what the callee does. */
lhs = get_function_part_constraint (fi, fi_uses);
rhs = get_function_part_constraint (cfi, fi_uses);
process_constraint (new_constraint (lhs, rhs));
return;
}
/* printf-style functions may have hooks to set pointers to
point to somewhere into the generated string. Leave them
for a later exercise... */
default:
/* Fallthru to general call handling. */;
}
/* Parameters passed by value are used. */
lhs = get_function_part_constraint (fi, fi_uses);
for (i = 0; i < gimple_call_num_args (t); i++)
{
struct constraint_expr *rhsp;
tree arg = gimple_call_arg (t, i);
if (TREE_CODE (arg) == SSA_NAME
|| is_gimple_min_invariant (arg))
continue;
get_constraint_for_address_of (arg, &rhsc);
FOR_EACH_VEC_ELT (rhsc, j, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
rhsc.truncate (0);
}
/* Build constraints for propagating clobbers/uses along the
callgraph edges. */
cfi = get_fi_for_callee (call_stmt);
if (cfi->id == anything_id)
{
if (gimple_vdef (t))
make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
anything_id);
make_constraint_from (first_vi_for_offset (fi, fi_uses),
anything_id);
return;
}
/* For callees without function info (that's external functions),
ESCAPED is clobbered and used. */
if (cfi->decl
&& TREE_CODE (cfi->decl) == FUNCTION_DECL
&& !cfi->is_fn_info)
{
varinfo_t vi;
if (gimple_vdef (t))
make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
escaped_id);
make_copy_constraint (first_vi_for_offset (fi, fi_uses), escaped_id);
/* Also honor the call statement use/clobber info. */
if ((vi = lookup_call_clobber_vi (call_stmt)) != NULL)
make_copy_constraint (first_vi_for_offset (fi, fi_clobbers),
vi->id);
if ((vi = lookup_call_use_vi (call_stmt)) != NULL)
make_copy_constraint (first_vi_for_offset (fi, fi_uses),
vi->id);
return;
}
/* Otherwise the caller clobbers and uses what the callee does.
??? This should use a new complex constraint that filters
local variables of the callee. */
if (gimple_vdef (t))
{
lhs = get_function_part_constraint (fi, fi_clobbers);
rhs = get_function_part_constraint (cfi, fi_clobbers);
process_constraint (new_constraint (lhs, rhs));
}
lhs = get_function_part_constraint (fi, fi_uses);
rhs = get_function_part_constraint (cfi, fi_uses);
process_constraint (new_constraint (lhs, rhs));
}
else if (gimple_code (t) == GIMPLE_ASM)
{
/* ??? Ick. We can do better. */
if (gimple_vdef (t))
make_constraint_from (first_vi_for_offset (fi, fi_clobbers),
anything_id);
make_constraint_from (first_vi_for_offset (fi, fi_uses),
anything_id);
}
}
/* This structure is used during pushing fields onto the fieldstack
to track the offset of the field, since bitpos_of_field gives it
relative to its immediate containing type, and we want it relative
to the ultimate containing object. */
struct fieldoff
{
/* Offset from the base of the base containing object to this field. */
HOST_WIDE_INT offset;
/* Size, in bits, of the field. */
unsigned HOST_WIDE_INT size;
unsigned has_unknown_size : 1;
unsigned must_have_pointers : 1;
unsigned may_have_pointers : 1;
unsigned only_restrict_pointers : 1;
tree restrict_pointed_type;
};
typedef struct fieldoff fieldoff_s;
/* qsort comparison function for two fieldoff's PA and PB. */
static int
fieldoff_compare (const void *pa, const void *pb)
{
const fieldoff_s *foa = (const fieldoff_s *)pa;
const fieldoff_s *fob = (const fieldoff_s *)pb;
unsigned HOST_WIDE_INT foasize, fobsize;
if (foa->offset < fob->offset)
return -1;
else if (foa->offset > fob->offset)
return 1;
foasize = foa->size;
fobsize = fob->size;
if (foasize < fobsize)
return -1;
else if (foasize > fobsize)
return 1;
return 0;
}
/* Sort a fieldstack according to the field offset and sizes. */
static void
sort_fieldstack (vec<fieldoff_s> &fieldstack)
{
fieldstack.qsort (fieldoff_compare);
}
/* Return true if T is a type that can have subvars. */
static inline bool
type_can_have_subvars (const_tree t)
{
/* Aggregates without overlapping fields can have subvars. */
return TREE_CODE (t) == RECORD_TYPE;
}
/* Return true if V is a tree that we can have subvars for.
Normally, this is any aggregate type. Also complex
types which are not gimple registers can have subvars. */
static inline bool
var_can_have_subvars (const_tree v)
{
/* Volatile variables should never have subvars. */
if (TREE_THIS_VOLATILE (v))
return false;
/* Non decls or memory tags can never have subvars. */
if (!DECL_P (v))
return false;
return type_can_have_subvars (TREE_TYPE (v));
}
/* Return true if T is a type that does contain pointers. */
static bool
type_must_have_pointers (tree type)
{
if (POINTER_TYPE_P (type))
return true;
if (TREE_CODE (type) == ARRAY_TYPE)
return type_must_have_pointers (TREE_TYPE (type));
/* A function or method can have pointers as arguments, so track
those separately. */
if (FUNC_OR_METHOD_TYPE_P (type))
return true;
return false;
}
static bool
field_must_have_pointers (tree t)
{
return type_must_have_pointers (TREE_TYPE (t));
}
/* Given a TYPE, and a vector of field offsets FIELDSTACK, push all
the fields of TYPE onto fieldstack, recording their offsets along
the way.
OFFSET is used to keep track of the offset in this entire
structure, rather than just the immediately containing structure.
Returns false if the caller is supposed to handle the field we
recursed for. */
static bool
push_fields_onto_fieldstack (tree type, vec<fieldoff_s> *fieldstack,
unsigned HOST_WIDE_INT offset)
{
tree field;
bool empty_p = true;
if (TREE_CODE (type) != RECORD_TYPE)
return false;
/* If the vector of fields is growing too big, bail out early.
Callers check for vec::length <= param_max_fields_for_field_sensitive, make
sure this fails. */
if (fieldstack->length () > (unsigned)param_max_fields_for_field_sensitive)
return false;
for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL)
{
bool push = false;
unsigned HOST_WIDE_INT foff = bitpos_of_field (field);
tree field_type = TREE_TYPE (field);
if (!var_can_have_subvars (field)
|| TREE_CODE (field_type) == QUAL_UNION_TYPE
|| TREE_CODE (field_type) == UNION_TYPE)
push = true;
else if (!push_fields_onto_fieldstack
(field_type, fieldstack, offset + foff)
&& (DECL_SIZE (field)
&& !integer_zerop (DECL_SIZE (field))))
/* Empty structures may have actual size, like in C++. So
see if we didn't push any subfields and the size is
nonzero, push the field onto the stack. */
push = true;
if (push)
{
fieldoff_s *pair = NULL;
bool has_unknown_size = false;
bool must_have_pointers_p;
if (!fieldstack->is_empty ())
pair = &fieldstack->last ();
/* If there isn't anything at offset zero, create sth. */
if (!pair
&& offset + foff != 0)
{
fieldoff_s e
= {0, offset + foff, false, false, true, false, NULL_TREE};
pair = fieldstack->safe_push (e);
}
if (!DECL_SIZE (field)
|| !tree_fits_uhwi_p (DECL_SIZE (field)))
has_unknown_size = true;
/* If adjacent fields do not contain pointers merge them. */
must_have_pointers_p = field_must_have_pointers (field);
if (pair
&& !has_unknown_size
&& !must_have_pointers_p
&& !pair->must_have_pointers
&& !pair->has_unknown_size
&& pair->offset + pair->size == offset + foff)
{
pair->size += tree_to_uhwi (DECL_SIZE (field));
}
else
{
fieldoff_s e;
e.offset = offset + foff;
e.has_unknown_size = has_unknown_size;
if (!has_unknown_size)
e.size = tree_to_uhwi (DECL_SIZE (field));
else
e.size = -1;
e.must_have_pointers = must_have_pointers_p;
e.may_have_pointers = true;
e.only_restrict_pointers
= (!has_unknown_size
&& POINTER_TYPE_P (field_type)
&& TYPE_RESTRICT (field_type));
if (e.only_restrict_pointers)
e.restrict_pointed_type = TREE_TYPE (field_type);
fieldstack->safe_push (e);
}
}
empty_p = false;
}
return !empty_p;
}
/* Count the number of arguments DECL has, and set IS_VARARGS to true
if it is a varargs function. */
static unsigned int
count_num_arguments (tree decl, bool *is_varargs)
{
unsigned int num = 0;
tree t;
/* Capture named arguments for K&R functions. They do not
have a prototype and thus no TYPE_ARG_TYPES. */
for (t = DECL_ARGUMENTS (decl); t; t = DECL_CHAIN (t))
++num;
/* Check if the function has variadic arguments. */
for (t = TYPE_ARG_TYPES (TREE_TYPE (decl)); t; t = TREE_CHAIN (t))
if (TREE_VALUE (t) == void_type_node)
break;
if (!t)
*is_varargs = true;
return num;
}
/* Creation function node for DECL, using NAME, and return the index
of the variable we've created for the function. If NONLOCAL_p, create
initial constraints. */
static varinfo_t
create_function_info_for (tree decl, const char *name, bool add_id,
bool nonlocal_p)
{
struct function *fn = DECL_STRUCT_FUNCTION (decl);
varinfo_t vi, prev_vi;
tree arg;
unsigned int i;
bool is_varargs = false;
unsigned int num_args = count_num_arguments (decl, &is_varargs);
/* Create the variable info. */
vi = new_var_info (decl, name, add_id);
vi->offset = 0;
vi->size = 1;
vi->fullsize = fi_parm_base + num_args;
vi->is_fn_info = 1;
vi->may_have_pointers = false;
if (is_varargs)
vi->fullsize = ~0;
insert_vi_for_tree (vi->decl, vi);
prev_vi = vi;
/* Create a variable for things the function clobbers and one for
things the function uses. */
{
varinfo_t clobbervi, usevi;
const char *newname;
char *tempname;
tempname = xasprintf ("%s.clobber", name);
newname = ggc_strdup (tempname);
free (tempname);
clobbervi = new_var_info (NULL, newname, false);
clobbervi->offset = fi_clobbers;
clobbervi->size = 1;
clobbervi->fullsize = vi->fullsize;
clobbervi->is_full_var = true;
clobbervi->is_global_var = false;
clobbervi->is_reg_var = true;
gcc_assert (prev_vi->offset < clobbervi->offset);
prev_vi->next = clobbervi->id;
prev_vi = clobbervi;
tempname = xasprintf ("%s.use", name);
newname = ggc_strdup (tempname);
free (tempname);
usevi = new_var_info (NULL, newname, false);
usevi->offset = fi_uses;
usevi->size = 1;
usevi->fullsize = vi->fullsize;
usevi->is_full_var = true;
usevi->is_global_var = false;
usevi->is_reg_var = true;
gcc_assert (prev_vi->offset < usevi->offset);
prev_vi->next = usevi->id;
prev_vi = usevi;
}
/* And one for the static chain. */
if (fn->static_chain_decl != NULL_TREE)
{
varinfo_t chainvi;
const char *newname;
char *tempname;
tempname = xasprintf ("%s.chain", name);
newname = ggc_strdup (tempname);
free (tempname);
chainvi = new_var_info (fn->static_chain_decl, newname, false);
chainvi->offset = fi_static_chain;
chainvi->size = 1;
chainvi->fullsize = vi->fullsize;
chainvi->is_full_var = true;
chainvi->is_global_var = false;
insert_vi_for_tree (fn->static_chain_decl, chainvi);
if (nonlocal_p
&& chainvi->may_have_pointers)
make_constraint_from (chainvi, nonlocal_id);
gcc_assert (prev_vi->offset < chainvi->offset);
prev_vi->next = chainvi->id;
prev_vi = chainvi;
}
/* Create a variable for the return var. */
if (DECL_RESULT (decl) != NULL
|| !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
{
varinfo_t resultvi;
const char *newname;
char *tempname;
tree resultdecl = decl;
if (DECL_RESULT (decl))
resultdecl = DECL_RESULT (decl);
tempname = xasprintf ("%s.result", name);
newname = ggc_strdup (tempname);
free (tempname);
resultvi = new_var_info (resultdecl, newname, false);
resultvi->offset = fi_result;
resultvi->size = 1;
resultvi->fullsize = vi->fullsize;
resultvi->is_full_var = true;
if (DECL_RESULT (decl))
resultvi->may_have_pointers = true;
if (DECL_RESULT (decl))
insert_vi_for_tree (DECL_RESULT (decl), resultvi);
if (nonlocal_p
&& DECL_RESULT (decl)
&& DECL_BY_REFERENCE (DECL_RESULT (decl)))
make_constraint_from (resultvi, nonlocal_id);
gcc_assert (prev_vi->offset < resultvi->offset);
prev_vi->next = resultvi->id;
prev_vi = resultvi;
}
/* We also need to make function return values escape. Nothing
escapes by returning from main though. */
if (nonlocal_p
&& !MAIN_NAME_P (DECL_NAME (decl)))
{
varinfo_t fi, rvi;
fi = lookup_vi_for_tree (decl);
rvi = first_vi_for_offset (fi, fi_result);
if (rvi && rvi->offset == fi_result)
make_copy_constraint (get_varinfo (escaped_id), rvi->id);
}
/* Set up variables for each argument. */
arg = DECL_ARGUMENTS (decl);
for (i = 0; i < num_args; i++)
{
varinfo_t argvi;
const char *newname;
char *tempname;
tree argdecl = decl;
if (arg)
argdecl = arg;
tempname = xasprintf ("%s.arg%d", name, i);
newname = ggc_strdup (tempname);
free (tempname);
argvi = new_var_info (argdecl, newname, false);
argvi->offset = fi_parm_base + i;
argvi->size = 1;
argvi->is_full_var = true;
argvi->fullsize = vi->fullsize;
if (arg)
argvi->may_have_pointers = true;
if (arg)
insert_vi_for_tree (arg, argvi);
if (nonlocal_p
&& argvi->may_have_pointers)
make_constraint_from (argvi, nonlocal_id);
gcc_assert (prev_vi->offset < argvi->offset);
prev_vi->next = argvi->id;
prev_vi = argvi;
if (arg)
arg = DECL_CHAIN (arg);
}
/* Add one representative for all further args. */
if (is_varargs)
{
varinfo_t argvi;
const char *newname;
char *tempname;
tree decl;
tempname = xasprintf ("%s.varargs", name);
newname = ggc_strdup (tempname);
free (tempname);
/* We need sth that can be pointed to for va_start. */
decl = build_fake_var_decl (ptr_type_node);
argvi = new_var_info (decl, newname, false);
argvi->offset = fi_parm_base + num_args;
argvi->size = ~0;
argvi->is_full_var = true;
argvi->is_heap_var = true;
argvi->fullsize = vi->fullsize;
if (nonlocal_p
&& argvi->may_have_pointers)
make_constraint_from (argvi, nonlocal_id);
gcc_assert (prev_vi->offset < argvi->offset);
prev_vi->next = argvi->id;
}
return vi;
}
/* Return true if FIELDSTACK contains fields that overlap.
FIELDSTACK is assumed to be sorted by offset. */
static bool
check_for_overlaps (const vec<fieldoff_s> &fieldstack)
{
fieldoff_s *fo = NULL;
unsigned int i;
HOST_WIDE_INT lastoffset = -1;
FOR_EACH_VEC_ELT (fieldstack, i, fo)
{
if (fo->offset == lastoffset)
return true;
lastoffset = fo->offset;
}
return false;
}
/* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
This will also create any varinfo structures necessary for fields
of DECL. DECL is a function parameter if HANDLE_PARAM is set.
HANDLED_STRUCT_TYPE is used to register struct types reached by following
restrict pointers. This is needed to prevent infinite recursion.
If ADD_RESTRICT, pretend that the pointer NAME is restrict even if DECL
does not advertise it. */
static varinfo_t
create_variable_info_for_1 (tree decl, const char *name, bool add_id,
bool handle_param, bitmap handled_struct_type,
bool add_restrict = false)
{
varinfo_t vi, newvi;
tree decl_type = TREE_TYPE (decl);
tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decl_type);
auto_vec<fieldoff_s> fieldstack;
fieldoff_s *fo;
unsigned int i;
if (!declsize
|| !tree_fits_uhwi_p (declsize))
{
vi = new_var_info (decl, name, add_id);
vi->offset = 0;
vi->size = ~0;
vi->fullsize = ~0;
vi->is_unknown_size_var = true;
vi->is_full_var = true;
vi->may_have_pointers = true;
return vi;
}
/* Collect field information. */
if (use_field_sensitive
&& var_can_have_subvars (decl)
/* ??? Force us to not use subfields for globals in IPA mode.
Else we'd have to parse arbitrary initializers. */
&& !(in_ipa_mode
&& is_global_var (decl)))
{
fieldoff_s *fo = NULL;
bool notokay = false;
unsigned int i;
push_fields_onto_fieldstack (decl_type, &fieldstack, 0);
for (i = 0; !notokay && fieldstack.iterate (i, &fo); i++)
if (fo->has_unknown_size
|| fo->offset < 0)
{
notokay = true;
break;
}
/* We can't sort them if we have a field with a variable sized type,
which will make notokay = true. In that case, we are going to return
without creating varinfos for the fields anyway, so sorting them is a
waste to boot. */
if (!notokay)
{
sort_fieldstack (fieldstack);
/* Due to some C++ FE issues, like PR 22488, we might end up
what appear to be overlapping fields even though they,
in reality, do not overlap. Until the C++ FE is fixed,
we will simply disable field-sensitivity for these cases. */
notokay = check_for_overlaps (fieldstack);
}
if (notokay)
fieldstack.release ();
}
/* If we didn't end up collecting sub-variables create a full
variable for the decl. */
if (fieldstack.length () == 0
|| fieldstack.length () > (unsigned)param_max_fields_for_field_sensitive)
{
vi = new_var_info (decl, name, add_id);
vi->offset = 0;
vi->may_have_pointers = true;
vi->fullsize = tree_to_uhwi (declsize);
vi->size = vi->fullsize;
vi->is_full_var = true;
if (POINTER_TYPE_P (decl_type)
&& (TYPE_RESTRICT (decl_type) || add_restrict))
vi->only_restrict_pointers = 1;
if (vi->only_restrict_pointers
&& !type_contains_placeholder_p (TREE_TYPE (decl_type))
&& handle_param
&& !bitmap_bit_p (handled_struct_type,
TYPE_UID (TREE_TYPE (decl_type))))
{
varinfo_t rvi;
tree heapvar = build_fake_var_decl (TREE_TYPE (decl_type));
DECL_EXTERNAL (heapvar) = 1;
if (var_can_have_subvars (heapvar))
bitmap_set_bit (handled_struct_type,
TYPE_UID (TREE_TYPE (decl_type)));
rvi = create_variable_info_for_1 (heapvar, "PARM_NOALIAS", true,
true, handled_struct_type);
if (var_can_have_subvars (heapvar))
bitmap_clear_bit (handled_struct_type,
TYPE_UID (TREE_TYPE (decl_type)));
rvi->is_restrict_var = 1;
insert_vi_for_tree (heapvar, rvi);
make_constraint_from (vi, rvi->id);
make_param_constraints (rvi);
}
fieldstack.release ();
return vi;
}
vi = new_var_info (decl, name, add_id);
vi->fullsize = tree_to_uhwi (declsize);
if (fieldstack.length () == 1)
vi->is_full_var = true;
for (i = 0, newvi = vi;
fieldstack.iterate (i, &fo);
++i, newvi = vi_next (newvi))
{
const char *newname = NULL;
char *tempname;
if (dump_file)
{
if (fieldstack.length () != 1)
{
tempname
= xasprintf ("%s." HOST_WIDE_INT_PRINT_DEC
"+" HOST_WIDE_INT_PRINT_DEC, name,
fo->offset, fo->size);
newname = ggc_strdup (tempname);
free (tempname);
}
}
else
newname = "NULL";
if (newname)
newvi->name = newname;
newvi->offset = fo->offset;
newvi->size = fo->size;
newvi->fullsize = vi->fullsize;
newvi->may_have_pointers = fo->may_have_pointers;
newvi->only_restrict_pointers = fo->only_restrict_pointers;
if (handle_param
&& newvi->only_restrict_pointers
&& !type_contains_placeholder_p (fo->restrict_pointed_type)
&& !bitmap_bit_p (handled_struct_type,
TYPE_UID (fo->restrict_pointed_type)))
{
varinfo_t rvi;
tree heapvar = build_fake_var_decl (fo->restrict_pointed_type);
DECL_EXTERNAL (heapvar) = 1;
if (var_can_have_subvars (heapvar))
bitmap_set_bit (handled_struct_type,
TYPE_UID (fo->restrict_pointed_type));
rvi = create_variable_info_for_1 (heapvar, "PARM_NOALIAS", true,
true, handled_struct_type);
if (var_can_have_subvars (heapvar))
bitmap_clear_bit (handled_struct_type,
TYPE_UID (fo->restrict_pointed_type));
rvi->is_restrict_var = 1;
insert_vi_for_tree (heapvar, rvi);
make_constraint_from (newvi, rvi->id);
make_param_constraints (rvi);
}
if (i + 1 < fieldstack.length ())
{
varinfo_t tem = new_var_info (decl, name, false);
newvi->next = tem->id;
tem->head = vi->id;
}
}
return vi;
}
static unsigned int
create_variable_info_for (tree decl, const char *name, bool add_id)
{
/* First see if we are dealing with an ifunc resolver call and
assiociate that with a call to the resolver function result. */
cgraph_node *node;
if (in_ipa_mode
&& TREE_CODE (decl) == FUNCTION_DECL
&& (node = cgraph_node::get (decl))
&& node->ifunc_resolver)
{
varinfo_t fi = get_vi_for_tree (node->get_alias_target ()->decl);
constraint_expr rhs
= get_function_part_constraint (fi, fi_result);
fi = new_var_info (NULL_TREE, "ifuncres", true);
fi->is_reg_var = true;
constraint_expr lhs;
lhs.type = SCALAR;
lhs.var = fi->id;
lhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
insert_vi_for_tree (decl, fi);
return fi->id;
}
varinfo_t vi = create_variable_info_for_1 (decl, name, add_id, false, NULL);
unsigned int id = vi->id;
insert_vi_for_tree (decl, vi);
if (!VAR_P (decl))
return id;
/* Create initial constraints for globals. */
for (; vi; vi = vi_next (vi))
{
if (!vi->may_have_pointers
|| !vi->is_global_var)
continue;
/* Mark global restrict qualified pointers. */
if ((POINTER_TYPE_P (TREE_TYPE (decl))
&& TYPE_RESTRICT (TREE_TYPE (decl)))
|| vi->only_restrict_pointers)
{
varinfo_t rvi
= make_constraint_from_global_restrict (vi, "GLOBAL_RESTRICT",
true);
/* ??? For now exclude reads from globals as restrict sources
if those are not (indirectly) from incoming parameters. */
rvi->is_restrict_var = false;
continue;
}
/* In non-IPA mode the initializer from nonlocal is all we need. */
if (!in_ipa_mode
|| DECL_HARD_REGISTER (decl))
make_copy_constraint (vi, nonlocal_id);
/* In IPA mode parse the initializer and generate proper constraints
for it. */
else
{
varpool_node *vnode = varpool_node::get (decl);
/* For escaped variables initialize them from nonlocal. */
if (!vnode || !vnode->all_refs_explicit_p ())
make_copy_constraint (vi, nonlocal_id);
/* While we can in theory walk references for the varpool
node that does not cover zero-initialization or references
to the constant pool. */
if (DECL_INITIAL (decl))
{
auto_vec<ce_s> rhsc;
struct constraint_expr lhs, *rhsp;
unsigned i;
lhs.var = vi->id;
lhs.offset = 0;
lhs.type = SCALAR;
get_constraint_for (DECL_INITIAL (decl), &rhsc);
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
/* If this is a variable that escapes from the unit
the initializer escapes as well. */
if (!vnode || !vnode->all_refs_explicit_p ())
{
lhs.var = escaped_id;
lhs.offset = 0;
lhs.type = SCALAR;
FOR_EACH_VEC_ELT (rhsc, i, rhsp)
process_constraint (new_constraint (lhs, *rhsp));
}
}
}
}
return id;
}
/* Register the constraints for function parameter related VI. */
static void
make_param_constraints (varinfo_t vi)
{
for (; vi; vi = vi_next (vi))
{
if (vi->only_restrict_pointers)
;
else if (vi->may_have_pointers)
make_constraint_from (vi, nonlocal_id);
if (vi->is_full_var)
break;
}
}
/* Create varinfo structures for all of the variables in the
function for intraprocedural mode. */
static void
intra_create_variable_infos (struct function *fn)
{
tree t;
bitmap handled_struct_type = NULL;
bool this_parm_in_ctor = DECL_CXX_CONSTRUCTOR_P (fn->decl);
/* For each incoming pointer argument arg, create the constraint ARG
= NONLOCAL or a dummy variable if it is a restrict qualified
passed-by-reference argument. */
for (t = DECL_ARGUMENTS (fn->decl); t; t = DECL_CHAIN (t))
{
if (handled_struct_type == NULL)
handled_struct_type = BITMAP_ALLOC (NULL);
varinfo_t p
= create_variable_info_for_1 (t, alias_get_name (t), false, true,
handled_struct_type, this_parm_in_ctor);
insert_vi_for_tree (t, p);
make_param_constraints (p);
this_parm_in_ctor = false;
}
if (handled_struct_type != NULL)
BITMAP_FREE (handled_struct_type);
/* Add a constraint for a result decl that is passed by reference. */
if (DECL_RESULT (fn->decl)
&& DECL_BY_REFERENCE (DECL_RESULT (fn->decl)))
{
varinfo_t p, result_vi = get_vi_for_tree (DECL_RESULT (fn->decl));
for (p = result_vi; p; p = vi_next (p))
make_constraint_from (p, nonlocal_id);
}
/* Add a constraint for the incoming static chain parameter. */
if (fn->static_chain_decl != NULL_TREE)
{
varinfo_t p, chain_vi = get_vi_for_tree (fn->static_chain_decl);
for (p = chain_vi; p; p = vi_next (p))
make_constraint_from (p, nonlocal_id);
}
}
/* Structure used to put solution bitmaps in a hashtable so they can
be shared among variables with the same points-to set. */
typedef struct shared_bitmap_info
{
bitmap pt_vars;
hashval_t hashcode;
} *shared_bitmap_info_t;
typedef const struct shared_bitmap_info *const_shared_bitmap_info_t;
/* Shared_bitmap hashtable helpers. */
struct shared_bitmap_hasher : free_ptr_hash <shared_bitmap_info>
{
static inline hashval_t hash (const shared_bitmap_info *);
static inline bool equal (const shared_bitmap_info *,
const shared_bitmap_info *);
};
/* Hash function for a shared_bitmap_info_t. */
inline hashval_t
shared_bitmap_hasher::hash (const shared_bitmap_info *bi)
{
return bi->hashcode;
}
/* Equality function for two shared_bitmap_info_t's. */
inline bool
shared_bitmap_hasher::equal (const shared_bitmap_info *sbi1,
const shared_bitmap_info *sbi2)
{
return bitmap_equal_p (sbi1->pt_vars, sbi2->pt_vars);
}
/* Shared_bitmap hashtable. */
static hash_table<shared_bitmap_hasher> *shared_bitmap_table;
/* Lookup a bitmap in the shared bitmap hashtable, and return an already
existing instance if there is one, NULL otherwise. */
static bitmap
shared_bitmap_lookup (bitmap pt_vars)
{
shared_bitmap_info **slot;
struct shared_bitmap_info sbi;
sbi.pt_vars = pt_vars;
sbi.hashcode = bitmap_hash (pt_vars);
slot = shared_bitmap_table->find_slot (&sbi, NO_INSERT);
if (!slot)
return NULL;
else
return (*slot)->pt_vars;
}
/* Add a bitmap to the shared bitmap hashtable. */
static void
shared_bitmap_add (bitmap pt_vars)
{
shared_bitmap_info **slot;
shared_bitmap_info_t sbi = XNEW (struct shared_bitmap_info);
sbi->pt_vars = pt_vars;
sbi->hashcode = bitmap_hash (pt_vars);
slot = shared_bitmap_table->find_slot (sbi, INSERT);
gcc_assert (!*slot);
*slot = sbi;
}
/* Set bits in INTO corresponding to the variable uids in solution set FROM. */
static void
set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt,
tree fndecl)
{
unsigned int i;
bitmap_iterator bi;
varinfo_t escaped_vi = get_varinfo (var_rep[escaped_id]);
varinfo_t escaped_return_vi = get_varinfo (var_rep[escaped_return_id]);
bool everything_escaped
= escaped_vi->solution && bitmap_bit_p (escaped_vi->solution, anything_id);
EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
{
varinfo_t vi = get_varinfo (i);
if (vi->is_artificial_var)
continue;
if (everything_escaped
|| (escaped_vi->solution
&& bitmap_bit_p (escaped_vi->solution, i)))
{
pt->vars_contains_escaped = true;
pt->vars_contains_escaped_heap |= vi->is_heap_var;
}
if (escaped_return_vi->solution
&& bitmap_bit_p (escaped_return_vi->solution, i))
pt->vars_contains_escaped_heap |= vi->is_heap_var;
if (vi->is_restrict_var)
pt->vars_contains_restrict = true;
if (VAR_P (vi->decl)
|| TREE_CODE (vi->decl) == PARM_DECL
|| TREE_CODE (vi->decl) == RESULT_DECL)
{
/* If we are in IPA mode we will not recompute points-to
sets after inlining so make sure they stay valid. */
if (in_ipa_mode
&& !DECL_PT_UID_SET_P (vi->decl))
SET_DECL_PT_UID (vi->decl, DECL_UID (vi->decl));
/* Add the decl to the points-to set. Note that the points-to
set contains global variables. */
bitmap_set_bit (into, DECL_PT_UID (vi->decl));
if (vi->is_global_var
/* In IPA mode the escaped_heap trick doesn't work as
ESCAPED is escaped from the unit but
pt_solution_includes_global needs to answer true for
all variables not automatic within a function.
For the same reason is_global_var is not the
correct flag to track - local variables from other
functions also need to be considered global.
Conveniently all HEAP vars are not put in function
scope. */
|| (in_ipa_mode
&& fndecl
&& ! auto_var_in_fn_p (vi->decl, fndecl)))
pt->vars_contains_nonlocal = true;
/* If we have a variable that is interposable record that fact
for pointer comparison simplification. */
if (VAR_P (vi->decl)
&& (TREE_STATIC (vi->decl) || DECL_EXTERNAL (vi->decl))
&& ! decl_binds_to_current_def_p (vi->decl))
pt->vars_contains_interposable = true;
/* If this is a local variable we can have overlapping lifetime
of different function invocations through recursion duplicate
it with its shadow variable. */
if (in_ipa_mode
&& vi->shadow_var_uid != 0)
{
bitmap_set_bit (into, vi->shadow_var_uid);
pt->vars_contains_nonlocal = true;
}
}
else if (TREE_CODE (vi->decl) == FUNCTION_DECL
|| TREE_CODE (vi->decl) == LABEL_DECL)
{
/* Nothing should read/write from/to code so we can
save bits by not including them in the points-to bitmaps.
Still mark the points-to set as containing global memory
to make code-patching possible - see PR70128. */
pt->vars_contains_nonlocal = true;
}
}
}
/* Compute the points-to solution *PT for the variable VI. */
static struct pt_solution
find_what_var_points_to (tree fndecl, varinfo_t orig_vi)
{
unsigned int i;
bitmap_iterator bi;
bitmap finished_solution;
bitmap result;
varinfo_t vi;
struct pt_solution *pt;
/* This variable may have been collapsed, let's get the real
variable. */
vi = get_varinfo (var_rep[orig_vi->id]);
/* See if we have already computed the solution and return it. */
pt_solution **slot = &final_solutions->get_or_insert (vi);
if (*slot != NULL)
return **slot;
*slot = pt = XOBNEW (&final_solutions_obstack, struct pt_solution);
memset (pt, 0, sizeof (struct pt_solution));
/* Translate artificial variables into SSA_NAME_PTR_INFO
attributes. */
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
{
varinfo_t vi = get_varinfo (i);
if (vi->is_artificial_var)
{
if (vi->id == nothing_id)
pt->null = 1;
else if (vi->id == escaped_id)
{
if (in_ipa_mode)
pt->ipa_escaped = 1;
else
pt->escaped = 1;
/* Expand some special vars of ESCAPED in-place here. */
varinfo_t evi = get_varinfo (var_rep[escaped_id]);
if (bitmap_bit_p (evi->solution, nonlocal_id))
pt->nonlocal = 1;
}
else if (vi->id == nonlocal_id)
pt->nonlocal = 1;
else if (vi->id == string_id)
pt->const_pool = 1;
else if (vi->id == anything_id
|| vi->id == integer_id)
pt->anything = 1;
}
}
/* Instead of doing extra work, simply do not create
elaborate points-to information for pt_anything pointers. */
if (pt->anything)
return *pt;
/* Share the final set of variables when possible. */
finished_solution = BITMAP_GGC_ALLOC ();
stats.points_to_sets_created++;
set_uids_in_ptset (finished_solution, vi->solution, pt, fndecl);
result = shared_bitmap_lookup (finished_solution);
if (!result)
{
shared_bitmap_add (finished_solution);
pt->vars = finished_solution;
}
else
{
pt->vars = result;
bitmap_clear (finished_solution);
}
return *pt;
}
/* Given a pointer variable P, fill in its points-to set. */
static void
find_what_p_points_to (tree fndecl, tree p)
{
struct ptr_info_def *pi;
tree lookup_p = p;
varinfo_t vi;
prange vr;
get_range_query (DECL_STRUCT_FUNCTION (fndecl))->range_of_expr (vr, p);
bool nonnull = vr.nonzero_p ();
/* For parameters, get at the points-to set for the actual parm
decl. */
if (TREE_CODE (p) == SSA_NAME
&& SSA_NAME_IS_DEFAULT_DEF (p)
&& (TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
|| TREE_CODE (SSA_NAME_VAR (p)) == RESULT_DECL))
lookup_p = SSA_NAME_VAR (p);
vi = lookup_vi_for_tree (lookup_p);
if (!vi)
return;
pi = get_ptr_info (p);
pi->pt = find_what_var_points_to (fndecl, vi);
/* Conservatively set to NULL from PTA (to true). */
pi->pt.null = 1;
/* Preserve pointer nonnull globally computed. */
if (nonnull)
set_ptr_nonnull (p);
}
/* Query statistics for points-to solutions. */
static struct {
unsigned HOST_WIDE_INT pt_solution_includes_may_alias;
unsigned HOST_WIDE_INT pt_solution_includes_no_alias;
unsigned HOST_WIDE_INT pt_solutions_intersect_may_alias;
unsigned HOST_WIDE_INT pt_solutions_intersect_no_alias;
} pta_stats;
void
dump_pta_stats (FILE *s)
{
fprintf (s, "\nPTA query stats:\n");
fprintf (s, " pt_solution_includes: "
HOST_WIDE_INT_PRINT_DEC" disambiguations, "
HOST_WIDE_INT_PRINT_DEC" queries\n",
pta_stats.pt_solution_includes_no_alias,
pta_stats.pt_solution_includes_no_alias
+ pta_stats.pt_solution_includes_may_alias);
fprintf (s, " pt_solutions_intersect: "
HOST_WIDE_INT_PRINT_DEC" disambiguations, "
HOST_WIDE_INT_PRINT_DEC" queries\n",
pta_stats.pt_solutions_intersect_no_alias,
pta_stats.pt_solutions_intersect_no_alias
+ pta_stats.pt_solutions_intersect_may_alias);
}
/* Reset the points-to solution *PT to a conservative default
(point to anything). */
void
pt_solution_reset (struct pt_solution *pt)
{
memset (pt, 0, sizeof (struct pt_solution));
pt->anything = true;
pt->null = true;
}
/* Set the points-to solution *PT to point only to the variables
in VARS. VARS_CONTAINS_GLOBAL specifies whether that contains
global variables and VARS_CONTAINS_RESTRICT specifies whether
it contains restrict tag variables. */
void
pt_solution_set (struct pt_solution *pt, bitmap vars,
bool vars_contains_nonlocal)
{
memset (pt, 0, sizeof (struct pt_solution));
pt->vars = vars;
pt->vars_contains_nonlocal = vars_contains_nonlocal;
pt->vars_contains_escaped
= (cfun->gimple_df->escaped.anything
|| bitmap_intersect_p (cfun->gimple_df->escaped.vars, vars));
}
/* Set the points-to solution *PT to point only to the variable VAR. */
void
pt_solution_set_var (struct pt_solution *pt, tree var)
{
memset (pt, 0, sizeof (struct pt_solution));
pt->vars = BITMAP_GGC_ALLOC ();
bitmap_set_bit (pt->vars, DECL_PT_UID (var));
pt->vars_contains_nonlocal = is_global_var (var);
pt->vars_contains_escaped
= (cfun->gimple_df->escaped.anything
|| bitmap_bit_p (cfun->gimple_df->escaped.vars, DECL_PT_UID (var)));
}
/* Computes the union of the points-to solutions *DEST and *SRC and
stores the result in *DEST. This changes the points-to bitmap
of *DEST and thus may not be used if that might be shared.
The points-to bitmap of *SRC and *DEST will not be shared after
this function if they were not before. */
static void
pt_solution_ior_into (struct pt_solution *dest, struct pt_solution *src)
{
dest->anything |= src->anything;
if (dest->anything)
{
pt_solution_reset (dest);
return;
}
dest->nonlocal |= src->nonlocal;
dest->escaped |= src->escaped;
dest->ipa_escaped |= src->ipa_escaped;
dest->null |= src->null;
dest->const_pool |= src->const_pool ;
dest->vars_contains_nonlocal |= src->vars_contains_nonlocal;
dest->vars_contains_escaped |= src->vars_contains_escaped;
dest->vars_contains_escaped_heap |= src->vars_contains_escaped_heap;
if (!src->vars)
return;
if (!dest->vars)
dest->vars = BITMAP_GGC_ALLOC ();
bitmap_ior_into (dest->vars, src->vars);
}
/* Return true if the points-to solution *PT is empty. */
bool
pt_solution_empty_p (const pt_solution *pt)
{
if (pt->anything
|| pt->nonlocal)
return false;
if (pt->vars
&& !bitmap_empty_p (pt->vars))
return false;
/* If the solution includes ESCAPED, check if that is empty. */
if (pt->escaped
&& !pt_solution_empty_p (&cfun->gimple_df->escaped))
return false;
/* If the solution includes ESCAPED, check if that is empty. */
if (pt->ipa_escaped
&& !pt_solution_empty_p (&ipa_escaped_pt))
return false;
return true;
}
/* Return true if the points-to solution *PT only point to a single var, and
return the var uid in *UID. */
bool
pt_solution_singleton_or_null_p (struct pt_solution *pt, unsigned *uid)
{
if (pt->anything || pt->nonlocal || pt->escaped || pt->ipa_escaped
|| pt->vars == NULL
|| !bitmap_single_bit_set_p (pt->vars))
return false;
*uid = bitmap_first_set_bit (pt->vars);
return true;
}
/* Return true if the points-to solution *PT includes global memory.
If ESCAPED_LOCAL_P is true then escaped local variables are also
considered global. */
bool
pt_solution_includes_global (struct pt_solution *pt, bool escaped_local_p)
{
if (pt->anything
|| pt->nonlocal
|| pt->vars_contains_nonlocal
/* The following is a hack to make the malloc escape hack work.
In reality we'd need different sets for escaped-through-return
and escaped-to-callees and passes would need to be updated. */
|| pt->vars_contains_escaped_heap)
return true;
if (escaped_local_p && pt->vars_contains_escaped)
return true;
/* 'escaped' is also a placeholder so we have to look into it. */
if (pt->escaped)
return pt_solution_includes_global (&cfun->gimple_df->escaped,
escaped_local_p);
if (pt->ipa_escaped)
return pt_solution_includes_global (&ipa_escaped_pt,
escaped_local_p);
return false;
}
/* Return true if the points-to solution *PT includes the variable
declaration DECL. */
static bool
pt_solution_includes_1 (struct pt_solution *pt, const_tree decl)
{
if (pt->anything)
return true;
if (pt->nonlocal
&& is_global_var (decl))
return true;
if (pt->vars
&& bitmap_bit_p (pt->vars, DECL_PT_UID (decl)))
return true;
/* If the solution includes ESCAPED, check it. */
if (pt->escaped
&& pt_solution_includes_1 (&cfun->gimple_df->escaped, decl))
return true;
/* If the solution includes ESCAPED, check it. */
if (pt->ipa_escaped
&& pt_solution_includes_1 (&ipa_escaped_pt, decl))
return true;
return false;
}
bool
pt_solution_includes (struct pt_solution *pt, const_tree decl)
{
bool res = pt_solution_includes_1 (pt, decl);
if (res)
++pta_stats.pt_solution_includes_may_alias;
else
++pta_stats.pt_solution_includes_no_alias;
return res;
}
/* Return true if the points-to solution *PT contains a reference to a
constant pool entry. */
bool
pt_solution_includes_const_pool (struct pt_solution *pt)
{
return (pt->const_pool
|| pt->nonlocal
|| (pt->escaped && (!cfun || cfun->gimple_df->escaped.const_pool))
|| (pt->ipa_escaped && ipa_escaped_pt.const_pool));
}
/* Return true if both points-to solutions PT1 and PT2 have a non-empty
intersection. */
static bool
pt_solutions_intersect_1 (struct pt_solution *pt1, struct pt_solution *pt2)
{
if (pt1->anything || pt2->anything)
return true;
/* If either points to unknown global memory and the other points to
any global memory they alias. */
if ((pt1->nonlocal
&& (pt2->nonlocal
|| pt2->vars_contains_nonlocal))
|| (pt2->nonlocal
&& pt1->vars_contains_nonlocal))
return true;
/* If either points to all escaped memory and the other points to
any escaped memory they alias. */
if ((pt1->escaped
&& (pt2->escaped
|| pt2->vars_contains_escaped))
|| (pt2->escaped
&& pt1->vars_contains_escaped))
return true;
/* Check the escaped solution if required.
??? Do we need to check the local against the IPA escaped sets? */
if ((pt1->ipa_escaped || pt2->ipa_escaped)
&& !pt_solution_empty_p (&ipa_escaped_pt))
{
/* If both point to escaped memory and that solution
is not empty they alias. */
if (pt1->ipa_escaped && pt2->ipa_escaped)
return true;
/* If either points to escaped memory see if the escaped solution
intersects with the other. */
if ((pt1->ipa_escaped
&& pt_solutions_intersect_1 (&ipa_escaped_pt, pt2))
|| (pt2->ipa_escaped
&& pt_solutions_intersect_1 (&ipa_escaped_pt, pt1)))
return true;
}
/* Now both pointers alias if their points-to solution intersects. */
return (pt1->vars
&& pt2->vars
&& bitmap_intersect_p (pt1->vars, pt2->vars));
}
bool
pt_solutions_intersect (struct pt_solution *pt1, struct pt_solution *pt2)
{
bool res = pt_solutions_intersect_1 (pt1, pt2);
if (res)
++pta_stats.pt_solutions_intersect_may_alias;
else
++pta_stats.pt_solutions_intersect_no_alias;
return res;
}
/* Initialize the always-existing constraint variables for NULL
ANYTHING, READONLY, and INTEGER */
static void
init_base_vars (void)
{
struct constraint_expr lhs, rhs;
varinfo_t var_anything;
varinfo_t var_nothing;
varinfo_t var_string;
varinfo_t var_escaped;
varinfo_t var_nonlocal;
varinfo_t var_escaped_return;
varinfo_t var_storedanything;
varinfo_t var_integer;
/* Variable ID zero is reserved and should be NULL. */
varmap.safe_push (NULL);
/* Create the NULL variable, used to represent that a variable points
to NULL. */
var_nothing = new_var_info (NULL_TREE, "NULL", false);
gcc_assert (var_nothing->id == nothing_id);
var_nothing->is_artificial_var = 1;
var_nothing->offset = 0;
var_nothing->size = ~0;
var_nothing->fullsize = ~0;
var_nothing->is_special_var = 1;
var_nothing->may_have_pointers = 0;
var_nothing->is_global_var = 0;
/* Create the ANYTHING variable, used to represent that a variable
points to some unknown piece of memory. */
var_anything = new_var_info (NULL_TREE, "ANYTHING", false);
gcc_assert (var_anything->id == anything_id);
var_anything->is_artificial_var = 1;
var_anything->size = ~0;
var_anything->offset = 0;
var_anything->fullsize = ~0;
var_anything->is_special_var = 1;
/* Anything points to anything. This makes deref constraints just
work in the presence of linked list and other p = *p type loops,
by saying that *ANYTHING = ANYTHING. */
lhs.type = SCALAR;
lhs.var = anything_id;
lhs.offset = 0;
rhs.type = ADDRESSOF;
rhs.var = anything_id;
rhs.offset = 0;
/* This specifically does not use process_constraint because
process_constraint ignores all anything = anything constraints, since all
but this one are redundant. */
constraints.safe_push (new_constraint (lhs, rhs));
/* Create the STRING variable, used to represent that a variable
points to a string literal. String literals don't contain
pointers so STRING doesn't point to anything. */
var_string = new_var_info (NULL_TREE, "STRING", false);
gcc_assert (var_string->id == string_id);
var_string->is_artificial_var = 1;
var_string->offset = 0;
var_string->size = ~0;
var_string->fullsize = ~0;
var_string->is_special_var = 1;
var_string->may_have_pointers = 0;
/* Create the ESCAPED variable, used to represent the set of escaped
memory. */
var_escaped = new_var_info (NULL_TREE, "ESCAPED", false);
gcc_assert (var_escaped->id == escaped_id);
var_escaped->is_artificial_var = 1;
var_escaped->offset = 0;
var_escaped->size = ~0;
var_escaped->fullsize = ~0;
var_escaped->is_special_var = 0;
/* Create the NONLOCAL variable, used to represent the set of nonlocal
memory. */
var_nonlocal = new_var_info (NULL_TREE, "NONLOCAL", false);
gcc_assert (var_nonlocal->id == nonlocal_id);
var_nonlocal->is_artificial_var = 1;
var_nonlocal->offset = 0;
var_nonlocal->size = ~0;
var_nonlocal->fullsize = ~0;
var_nonlocal->is_special_var = 1;
/* Create the ESCAPED_RETURN variable, used to represent the set of escaped
memory via a regular return stmt. */
var_escaped_return = new_var_info (NULL_TREE, "ESCAPED_RETURN", false);
gcc_assert (var_escaped_return->id == escaped_return_id);
var_escaped_return->is_artificial_var = 1;
var_escaped_return->offset = 0;
var_escaped_return->size = ~0;
var_escaped_return->fullsize = ~0;
var_escaped_return->is_special_var = 0;
/* ESCAPED = *ESCAPED, because escaped is may-deref'd at calls, etc. */
lhs.type = SCALAR;
lhs.var = escaped_id;
lhs.offset = 0;
rhs.type = DEREF;
rhs.var = escaped_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* ESCAPED = ESCAPED + UNKNOWN_OFFSET, because if a sub-field escapes the
whole variable escapes. */
lhs.type = SCALAR;
lhs.var = escaped_id;
lhs.offset = 0;
rhs.type = SCALAR;
rhs.var = escaped_id;
rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
/* *ESCAPED = NONLOCAL. This is true because we have to assume
everything pointed to by escaped points to what global memory can
point to. */
lhs.type = DEREF;
lhs.var = escaped_id;
lhs.offset = 0;
rhs.type = SCALAR;
rhs.var = nonlocal_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* NONLOCAL = &NONLOCAL, NONLOCAL = &ESCAPED. This is true because
global memory may point to global memory and escaped memory. */
lhs.type = SCALAR;
lhs.var = nonlocal_id;
lhs.offset = 0;
rhs.type = ADDRESSOF;
rhs.var = nonlocal_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
rhs.type = ADDRESSOF;
rhs.var = escaped_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* Transitively close ESCAPED_RETURN.
ESCAPED_RETURN = ESCAPED_RETURN + UNKNOWN_OFFSET
ESCAPED_RETURN = *ESCAPED_RETURN. */
lhs.type = SCALAR;
lhs.var = escaped_return_id;
lhs.offset = 0;
rhs.type = SCALAR;
rhs.var = escaped_return_id;
rhs.offset = UNKNOWN_OFFSET;
process_constraint (new_constraint (lhs, rhs));
lhs.type = SCALAR;
lhs.var = escaped_return_id;
lhs.offset = 0;
rhs.type = DEREF;
rhs.var = escaped_return_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
/* Create the STOREDANYTHING variable, used to represent the set of
variables stored to *ANYTHING. */
var_storedanything = new_var_info (NULL_TREE, "STOREDANYTHING", false);
gcc_assert (var_storedanything->id == storedanything_id);
var_storedanything->is_artificial_var = 1;
var_storedanything->offset = 0;
var_storedanything->size = ~0;
var_storedanything->fullsize = ~0;
var_storedanything->is_special_var = 0;
/* Create the INTEGER variable, used to represent that a variable points
to what an INTEGER "points to". */
var_integer = new_var_info (NULL_TREE, "INTEGER", false);
gcc_assert (var_integer->id == integer_id);
var_integer->is_artificial_var = 1;
var_integer->size = ~0;
var_integer->fullsize = ~0;
var_integer->offset = 0;
var_integer->is_special_var = 1;
/* INTEGER = ANYTHING, because we don't know where a dereference of
a random integer will point to. */
lhs.type = SCALAR;
lhs.var = integer_id;
lhs.offset = 0;
rhs.type = ADDRESSOF;
rhs.var = anything_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
}
/* Initialize things necessary to perform PTA. */
static void
init_alias_vars (void)
{
use_field_sensitive = (param_max_fields_for_field_sensitive > 1);
bitmap_obstack_initialize (&pta_obstack);
bitmap_obstack_initialize (&oldpta_obstack);
constraints.create (8);
varmap.create (8);
vi_for_tree = new hash_map<tree, varinfo_t>;
call_stmt_vars = new hash_map<gimple *, varinfo_t>;
memset (&stats, 0, sizeof (stats));
shared_bitmap_table = new hash_table<shared_bitmap_hasher> (511);
init_base_vars ();
gcc_obstack_init (&fake_var_decl_obstack);
final_solutions = new hash_map<varinfo_t, pt_solution *>;
gcc_obstack_init (&final_solutions_obstack);
}
/* Create points-to sets for the current function. See the comments
at the start of the file for an algorithmic overview. */
static void
compute_points_to_sets (void)
{
basic_block bb;
varinfo_t vi;
timevar_push (TV_TREE_PTA);
init_alias_vars ();
intra_create_variable_infos (cfun);
/* Now walk all statements and build the constraint set. */
FOR_EACH_BB_FN (bb, cfun)
{
for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
{
gphi *phi = gsi.phi ();
if (! virtual_operand_p (gimple_phi_result (phi)))
find_func_aliases (cfun, phi);
}
for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
find_func_aliases (cfun, stmt);
}
}
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
dump_constraints (dump_file, 0);
}
/* From the constraints compute the points-to sets. */
solve_constraints ();
if (dump_file && (dump_flags & TDF_STATS))
dump_sa_stats (dump_file);
if (dump_file && (dump_flags & TDF_DETAILS))
dump_sa_points_to_info (dump_file);
/* Compute the points-to set for ESCAPED used for call-clobber analysis. */
cfun->gimple_df->escaped = find_what_var_points_to (cfun->decl,
get_varinfo (escaped_id));
/* Make sure the ESCAPED solution (which is used as placeholder in
other solutions) does not reference itself. This simplifies
points-to solution queries. */
cfun->gimple_df->escaped.escaped = 0;
/* The ESCAPED_RETURN solution is what contains all memory that needs
to be considered global. */
cfun->gimple_df->escaped_return
= find_what_var_points_to (cfun->decl, get_varinfo (escaped_return_id));
cfun->gimple_df->escaped_return.escaped = 1;
/* Compute the points-to sets for pointer SSA_NAMEs. */
unsigned i;
tree ptr;
FOR_EACH_SSA_NAME (i, ptr, cfun)
{
if (POINTER_TYPE_P (TREE_TYPE (ptr)))
find_what_p_points_to (cfun->decl, ptr);
}
/* Compute the call-used/clobbered sets. */
FOR_EACH_BB_FN (bb, cfun)
{
gimple_stmt_iterator gsi;
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gcall *stmt;
struct pt_solution *pt;
stmt = dyn_cast <gcall *> (gsi_stmt (gsi));
if (!stmt)
continue;
pt = gimple_call_use_set (stmt);
if (gimple_call_flags (stmt) & ECF_CONST)
memset (pt, 0, sizeof (struct pt_solution));
else
{
bool uses_global_memory = true;
bool reads_global_memory = true;
determine_global_memory_access (stmt, NULL,
&reads_global_memory,
&uses_global_memory);
if ((vi = lookup_call_use_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (cfun->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly used by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
always escaped. */
if (uses_global_memory)
{
pt->nonlocal = 1;
pt->escaped = 1;
}
}
else if (uses_global_memory)
{
/* If there is nothing special about this call then
we have made everything that is used also escape. */
*pt = cfun->gimple_df->escaped;
pt->nonlocal = 1;
}
else
memset (pt, 0, sizeof (struct pt_solution));
}
pt = gimple_call_clobber_set (stmt);
if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
memset (pt, 0, sizeof (struct pt_solution));
else
{
bool writes_global_memory = true;
determine_global_memory_access (stmt, &writes_global_memory,
NULL, NULL);
if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (cfun->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly clobbered by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
always escaped. */
if (writes_global_memory)
{
pt->nonlocal = 1;
pt->escaped = 1;
}
}
else if (writes_global_memory)
{
/* If there is nothing special about this call then
we have made everything that is used also escape. */
*pt = cfun->gimple_df->escaped;
pt->nonlocal = 1;
}
else
memset (pt, 0, sizeof (struct pt_solution));
}
}
}
timevar_pop (TV_TREE_PTA);
}
/* Delete created points-to sets. */
static void
delete_points_to_sets (void)
{
delete shared_bitmap_table;
shared_bitmap_table = NULL;
if (dump_file && (dump_flags & TDF_STATS))
fprintf (dump_file, "Points to sets created:%d\n",
stats.points_to_sets_created);
delete vi_for_tree;
delete call_stmt_vars;
bitmap_obstack_release (&pta_obstack);
constraints.release ();
free (var_rep);
varmap.release ();
variable_info_pool.release ();
constraint_pool.release ();
obstack_free (&fake_var_decl_obstack, NULL);
delete final_solutions;
obstack_free (&final_solutions_obstack, NULL);
}
struct vls_data
{
unsigned short clique;
bool escaped_p;
bitmap rvars;
};
/* Mark "other" loads and stores as belonging to CLIQUE and with
base zero. */
static bool
visit_loadstore (gimple *, tree base, tree ref, void *data)
{
unsigned short clique = ((vls_data *) data)->clique;
bitmap rvars = ((vls_data *) data)->rvars;
bool escaped_p = ((vls_data *) data)->escaped_p;
if (TREE_CODE (base) == MEM_REF
|| TREE_CODE (base) == TARGET_MEM_REF)
{
tree ptr = TREE_OPERAND (base, 0);
if (TREE_CODE (ptr) == SSA_NAME)
{
/* For parameters, get at the points-to set for the actual parm
decl. */
if (SSA_NAME_IS_DEFAULT_DEF (ptr)
&& (TREE_CODE (SSA_NAME_VAR (ptr)) == PARM_DECL
|| TREE_CODE (SSA_NAME_VAR (ptr)) == RESULT_DECL))
ptr = SSA_NAME_VAR (ptr);
/* We need to make sure 'ptr' doesn't include any of
the restrict tags we added bases for in its points-to set. */
varinfo_t vi = lookup_vi_for_tree (ptr);
if (! vi)
return false;
vi = get_varinfo (var_rep[vi->id]);
if (bitmap_intersect_p (rvars, vi->solution)
|| (escaped_p && bitmap_bit_p (vi->solution, escaped_id)))
return false;
}
/* Do not overwrite existing cliques (that includes clique, base
pairs we just set). */
if (MR_DEPENDENCE_CLIQUE (base) == 0)
{
MR_DEPENDENCE_CLIQUE (base) = clique;
MR_DEPENDENCE_BASE (base) = 0;
}
}
/* For plain decl accesses see whether they are accesses to globals
and rewrite them to MEM_REFs with { clique, 0 }. */
if (VAR_P (base)
&& is_global_var (base)
/* ??? We can't rewrite a plain decl with the walk_stmt_load_store
ops callback. */
&& base != ref)
{
tree *basep = &ref;
while (handled_component_p (*basep))
basep = &TREE_OPERAND (*basep, 0);
gcc_assert (VAR_P (*basep));
tree ptr = build_fold_addr_expr (*basep);
tree zero = build_int_cst (TREE_TYPE (ptr), 0);
*basep = build2 (MEM_REF, TREE_TYPE (*basep), ptr, zero);
MR_DEPENDENCE_CLIQUE (*basep) = clique;
MR_DEPENDENCE_BASE (*basep) = 0;
}
return false;
}
struct msdi_data {
tree ptr;
unsigned short *clique;
unsigned short *last_ruid;
varinfo_t restrict_var;
};
/* If BASE is a MEM_REF then assign a clique, base pair to it, updating
CLIQUE, *RESTRICT_VAR and LAST_RUID as passed via DATA.
Return whether dependence info was assigned to BASE. */
static bool
maybe_set_dependence_info (gimple *, tree base, tree, void *data)
{
tree ptr = ((msdi_data *)data)->ptr;
unsigned short &clique = *((msdi_data *)data)->clique;
unsigned short &last_ruid = *((msdi_data *)data)->last_ruid;
varinfo_t restrict_var = ((msdi_data *)data)->restrict_var;
if ((TREE_CODE (base) == MEM_REF
|| TREE_CODE (base) == TARGET_MEM_REF)
&& TREE_OPERAND (base, 0) == ptr)
{
/* Do not overwrite existing cliques. This avoids overwriting dependence
info inlined from a function with restrict parameters inlined
into a function with restrict parameters. This usually means we
prefer to be precise in innermost loops. */
if (MR_DEPENDENCE_CLIQUE (base) == 0)
{
if (clique == 0)
{
if (cfun->last_clique == 0)
cfun->last_clique = 1;
clique = 1;
}
if (restrict_var->ruid == 0)
restrict_var->ruid = ++last_ruid;
MR_DEPENDENCE_CLIQUE (base) = clique;
MR_DEPENDENCE_BASE (base) = restrict_var->ruid;
return true;
}
}
return false;
}
/* Clear dependence info for the clique DATA. */
static bool
clear_dependence_clique (gimple *, tree base, tree, void *data)
{
unsigned short clique = (uintptr_t)data;
if ((TREE_CODE (base) == MEM_REF
|| TREE_CODE (base) == TARGET_MEM_REF)
&& MR_DEPENDENCE_CLIQUE (base) == clique)
{
MR_DEPENDENCE_CLIQUE (base) = 0;
MR_DEPENDENCE_BASE (base) = 0;
}
return false;
}
/* Compute the set of independend memory references based on restrict
tags and their conservative propagation to the points-to sets. */
static void
compute_dependence_clique (void)
{
/* First clear the special "local" clique. */
basic_block bb;
if (cfun->last_clique != 0)
FOR_EACH_BB_FN (bb, cfun)
for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
!gsi_end_p (gsi); gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
walk_stmt_load_store_ops (stmt, (void *)(uintptr_t) 1,
clear_dependence_clique,
clear_dependence_clique);
}
unsigned short clique = 0;
unsigned short last_ruid = 0;
bitmap rvars = BITMAP_ALLOC (NULL);
bool escaped_p = false;
for (unsigned i = 0; i < num_ssa_names; ++i)
{
tree ptr = ssa_name (i);
if (!ptr || !POINTER_TYPE_P (TREE_TYPE (ptr)))
continue;
/* Avoid all this when ptr is not dereferenced? */
tree p = ptr;
if (SSA_NAME_IS_DEFAULT_DEF (ptr)
&& (TREE_CODE (SSA_NAME_VAR (ptr)) == PARM_DECL
|| TREE_CODE (SSA_NAME_VAR (ptr)) == RESULT_DECL))
p = SSA_NAME_VAR (ptr);
varinfo_t vi = lookup_vi_for_tree (p);
if (!vi)
continue;
vi = get_varinfo (var_rep[vi->id]);
bitmap_iterator bi;
unsigned j;
varinfo_t restrict_var = NULL;
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, j, bi)
{
varinfo_t oi = get_varinfo (j);
if (oi->head != j)
oi = get_varinfo (oi->head);
if (oi->is_restrict_var)
{
if (restrict_var
&& restrict_var != oi)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "found restrict pointed-to "
"for ");
print_generic_expr (dump_file, ptr);
fprintf (dump_file, " but not exclusively\n");
}
restrict_var = NULL;
break;
}
restrict_var = oi;
}
/* NULL is the only other valid points-to entry. */
else if (oi->id != nothing_id)
{
restrict_var = NULL;
break;
}
}
/* Ok, found that ptr must(!) point to a single(!) restrict
variable. */
/* ??? PTA isn't really a proper propagation engine to compute
this property.
??? We could handle merging of two restricts by unifying them. */
if (restrict_var)
{
/* Now look at possible dereferences of ptr. */
imm_use_iterator ui;
gimple *use_stmt;
bool used = false;
msdi_data data = { ptr, &clique, &last_ruid, restrict_var };
FOR_EACH_IMM_USE_STMT (use_stmt, ui, ptr)
used |= walk_stmt_load_store_ops (use_stmt, &data,
maybe_set_dependence_info,
maybe_set_dependence_info);
if (used)
{
/* Add all subvars to the set of restrict pointed-to set. */
for (unsigned sv = restrict_var->head; sv != 0;
sv = get_varinfo (sv)->next)
bitmap_set_bit (rvars, sv);
varinfo_t escaped = get_varinfo (var_rep[escaped_id]);
if (bitmap_bit_p (escaped->solution, restrict_var->id))
escaped_p = true;
}
}
}
if (clique != 0)
{
/* Assign the BASE id zero to all accesses not based on a restrict
pointer. That way they get disambiguated against restrict
accesses but not against each other. */
/* ??? For restricts derived from globals (thus not incoming
parameters) we can't restrict scoping properly thus the following
is too aggressive there. For now we have excluded those globals from
getting into the MR_DEPENDENCE machinery. */
vls_data data = { clique, escaped_p, rvars };
basic_block bb;
FOR_EACH_BB_FN (bb, cfun)
for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
!gsi_end_p (gsi); gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
walk_stmt_load_store_ops (stmt, &data,
visit_loadstore, visit_loadstore);
}
}
BITMAP_FREE (rvars);
}
/* Compute points-to information for every SSA_NAME pointer in the
current function and compute the transitive closure of escaped
variables to re-initialize the call-clobber states of local variables. */
unsigned int
compute_may_aliases (void)
{
if (cfun->gimple_df->ipa_pta)
{
if (dump_file)
{
fprintf (dump_file, "\nNot re-computing points-to information "
"because IPA points-to information is available.\n\n");
/* But still dump what we have remaining it. */
if (dump_flags & (TDF_DETAILS|TDF_ALIAS))
dump_alias_info (dump_file);
}
return 0;
}
/* For each pointer P_i, determine the sets of variables that P_i may
point-to. Compute the reachability set of escaped and call-used
variables. */
compute_points_to_sets ();
/* Debugging dumps. */
if (dump_file && (dump_flags & (TDF_DETAILS|TDF_ALIAS)))
dump_alias_info (dump_file);
/* Compute restrict-based memory disambiguations. */
compute_dependence_clique ();
/* Deallocate memory used by aliasing data structures and the internal
points-to solution. */
delete_points_to_sets ();
gcc_assert (!need_ssa_update_p (cfun));
return 0;
}
/* A dummy pass to cause points-to information to be computed via
TODO_rebuild_alias. */
namespace {
const pass_data pass_data_build_alias =
{
GIMPLE_PASS, /* type */
"alias", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_NONE, /* tv_id */
( PROP_cfg | PROP_ssa ), /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_rebuild_alias, /* todo_flags_finish */
};
class pass_build_alias : public gimple_opt_pass
{
public:
pass_build_alias (gcc::context *ctxt)
: gimple_opt_pass (pass_data_build_alias, ctxt)
{}
/* opt_pass methods: */
bool gate (function *) final override { return flag_tree_pta; }
}; // class pass_build_alias
} // anon namespace
gimple_opt_pass *
make_pass_build_alias (gcc::context *ctxt)
{
return new pass_build_alias (ctxt);
}
/* A dummy pass to cause points-to information to be computed via
TODO_rebuild_alias. */
namespace {
const pass_data pass_data_build_ealias =
{
GIMPLE_PASS, /* type */
"ealias", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_NONE, /* tv_id */
( PROP_cfg | PROP_ssa ), /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_rebuild_alias, /* todo_flags_finish */
};
class pass_build_ealias : public gimple_opt_pass
{
public:
pass_build_ealias (gcc::context *ctxt)
: gimple_opt_pass (pass_data_build_ealias, ctxt)
{}
/* opt_pass methods: */
bool gate (function *) final override { return flag_tree_pta; }
}; // class pass_build_ealias
} // anon namespace
gimple_opt_pass *
make_pass_build_ealias (gcc::context *ctxt)
{
return new pass_build_ealias (ctxt);
}
/* IPA PTA solutions for ESCAPED. */
struct pt_solution ipa_escaped_pt
= { true, false, false, false, false, false,
false, false, false, false, false, NULL };
/* Associate node with varinfo DATA. Worker for
cgraph_for_symbol_thunks_and_aliases. */
static bool
associate_varinfo_to_alias (struct cgraph_node *node, void *data)
{
if ((node->alias
|| (node->thunk
&& ! node->inlined_to))
&& node->analyzed
&& !node->ifunc_resolver)
insert_vi_for_tree (node->decl, (varinfo_t)data);
return false;
}
/* Compute whether node is refered to non-locally. Worker for
cgraph_for_symbol_thunks_and_aliases. */
static bool
refered_from_nonlocal_fn (struct cgraph_node *node, void *data)
{
bool *nonlocal_p = (bool *)data;
*nonlocal_p |= (node->used_from_other_partition
|| DECL_EXTERNAL (node->decl)
|| TREE_PUBLIC (node->decl)
|| node->force_output
|| lookup_attribute ("noipa", DECL_ATTRIBUTES (node->decl)));
return false;
}
/* Same for varpool nodes. */
static bool
refered_from_nonlocal_var (struct varpool_node *node, void *data)
{
bool *nonlocal_p = (bool *)data;
*nonlocal_p |= (node->used_from_other_partition
|| DECL_EXTERNAL (node->decl)
|| TREE_PUBLIC (node->decl)
|| node->force_output);
return false;
}
/* Execute the driver for IPA PTA. */
static unsigned int
ipa_pta_execute (void)
{
struct cgraph_node *node;
varpool_node *var;
unsigned int from = 0;
in_ipa_mode = 1;
init_alias_vars ();
if (dump_file && (dump_flags & TDF_DETAILS))
{
symtab->dump (dump_file);
fprintf (dump_file, "\n");
}
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Generating generic constraints\n\n");
dump_constraints (dump_file, from);
fprintf (dump_file, "\n");
from = constraints.length ();
}
/* Build the constraints. */
FOR_EACH_DEFINED_FUNCTION (node)
{
varinfo_t vi;
/* Nodes without a body in this partition are not interesting.
Especially do not visit clones at this point for now - we
get duplicate decls there for inline clones at least. */
if (!node->has_gimple_body_p ()
|| node->in_other_partition
|| node->inlined_to)
continue;
node->get_body ();
gcc_assert (!node->clone_of);
/* For externally visible or attribute used annotated functions use
local constraints for their arguments.
For local functions we see all callers and thus do not need initial
constraints for parameters. */
bool nonlocal_p = (node->used_from_other_partition
|| DECL_EXTERNAL (node->decl)
|| TREE_PUBLIC (node->decl)
|| node->force_output
|| lookup_attribute ("noipa",
DECL_ATTRIBUTES (node->decl)));
node->call_for_symbol_thunks_and_aliases (refered_from_nonlocal_fn,
&nonlocal_p, true);
vi = create_function_info_for (node->decl,
alias_get_name (node->decl), false,
nonlocal_p);
if (dump_file && (dump_flags & TDF_DETAILS)
&& from != constraints.length ())
{
fprintf (dump_file,
"Generating initial constraints for %s",
node->dump_name ());
if (DECL_ASSEMBLER_NAME_SET_P (node->decl))
fprintf (dump_file, " (%s)",
IDENTIFIER_POINTER
(DECL_ASSEMBLER_NAME (node->decl)));
fprintf (dump_file, "\n\n");
dump_constraints (dump_file, from);
fprintf (dump_file, "\n");
from = constraints.length ();
}
node->call_for_symbol_thunks_and_aliases
(associate_varinfo_to_alias, vi, true);
}
/* Create constraints for global variables and their initializers. */
FOR_EACH_VARIABLE (var)
{
if (var->alias && var->analyzed)
continue;
varinfo_t vi = get_vi_for_tree (var->decl);
/* For the purpose of IPA PTA unit-local globals are not
escape points. */
bool nonlocal_p = (DECL_EXTERNAL (var->decl)
|| TREE_PUBLIC (var->decl)
|| var->used_from_other_partition
|| var->force_output);
var->call_for_symbol_and_aliases (refered_from_nonlocal_var,
&nonlocal_p, true);
if (nonlocal_p)
vi->is_ipa_escape_point = true;
}
if (dump_file && (dump_flags & TDF_DETAILS)
&& from != constraints.length ())
{
fprintf (dump_file,
"Generating constraints for global initializers\n\n");
dump_constraints (dump_file, from);
fprintf (dump_file, "\n");
from = constraints.length ();
}
FOR_EACH_DEFINED_FUNCTION (node)
{
struct function *func;
basic_block bb;
/* Nodes without a body in this partition are not interesting. */
if (!node->has_gimple_body_p ()
|| node->in_other_partition
|| node->clone_of)
continue;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
"Generating constraints for %s", node->dump_name ());
if (DECL_ASSEMBLER_NAME_SET_P (node->decl))
fprintf (dump_file, " (%s)",
IDENTIFIER_POINTER
(DECL_ASSEMBLER_NAME (node->decl)));
fprintf (dump_file, "\n");
}
func = DECL_STRUCT_FUNCTION (node->decl);
gcc_assert (cfun == NULL);
/* Build constriants for the function body. */
FOR_EACH_BB_FN (bb, func)
{
for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
{
gphi *phi = gsi.phi ();
if (! virtual_operand_p (gimple_phi_result (phi)))
find_func_aliases (func, phi);
}
for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
find_func_aliases (func, stmt);
find_func_clobbers (func, stmt);
}
}
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "\n");
dump_constraints (dump_file, from);
fprintf (dump_file, "\n");
from = constraints.length ();
}
}
/* From the constraints compute the points-to sets. */
solve_constraints ();
if (dump_file && (dump_flags & TDF_STATS))
dump_sa_stats (dump_file);
if (dump_file && (dump_flags & TDF_DETAILS))
dump_sa_points_to_info (dump_file);
/* Now post-process solutions to handle locals from different
runtime instantiations coming in through recursive invocations. */
unsigned shadow_var_cnt = 0;
for (unsigned i = 1; i < varmap.length (); ++i)
{
varinfo_t fi = get_varinfo (i);
if (fi->is_fn_info
&& fi->decl)
/* Automatic variables pointed to by their containing functions
parameters need this treatment. */
for (varinfo_t ai = first_vi_for_offset (fi, fi_parm_base);
ai; ai = vi_next (ai))
{
varinfo_t vi = get_varinfo (var_rep[ai->id]);
bitmap_iterator bi;
unsigned j;
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, j, bi)
{
varinfo_t pt = get_varinfo (j);
if (pt->shadow_var_uid == 0
&& pt->decl
&& auto_var_in_fn_p (pt->decl, fi->decl))
{
pt->shadow_var_uid = allocate_decl_uid ();
shadow_var_cnt++;
}
}
}
/* As well as global variables which are another way of passing
arguments to recursive invocations. */
else if (fi->is_global_var)
{
for (varinfo_t ai = fi; ai; ai = vi_next (ai))
{
varinfo_t vi = get_varinfo (var_rep[ai->id]);
bitmap_iterator bi;
unsigned j;
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, j, bi)
{
varinfo_t pt = get_varinfo (j);
if (pt->shadow_var_uid == 0
&& pt->decl
&& auto_var_p (pt->decl))
{
pt->shadow_var_uid = allocate_decl_uid ();
shadow_var_cnt++;
}
}
}
}
}
if (shadow_var_cnt && dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Allocated %u shadow variables for locals "
"maybe leaking into recursive invocations of their containing "
"functions\n", shadow_var_cnt);
/* Compute the global points-to sets for ESCAPED.
??? Note that the computed escape set is not correct
for the whole unit as we fail to consider graph edges to
externally visible functions. */
ipa_escaped_pt = find_what_var_points_to (NULL, get_varinfo (escaped_id));
/* Make sure the ESCAPED solution (which is used as placeholder in
other solutions) does not reference itself. This simplifies
points-to solution queries. */
ipa_escaped_pt.ipa_escaped = 0;
/* Assign the points-to sets to the SSA names in the unit. */
FOR_EACH_DEFINED_FUNCTION (node)
{
tree ptr;
struct function *fn;
unsigned i;
basic_block bb;
/* Nodes without a body in this partition are not interesting. */
if (!node->has_gimple_body_p ()
|| node->in_other_partition
|| node->clone_of)
continue;
fn = DECL_STRUCT_FUNCTION (node->decl);
/* Compute the points-to sets for pointer SSA_NAMEs. */
FOR_EACH_VEC_ELT (*fn->gimple_df->ssa_names, i, ptr)
{
if (ptr
&& POINTER_TYPE_P (TREE_TYPE (ptr)))
find_what_p_points_to (node->decl, ptr);
}
/* Compute the call-use and call-clobber sets for indirect calls
and calls to external functions. */
FOR_EACH_BB_FN (bb, fn)
{
gimple_stmt_iterator gsi;
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gcall *stmt;
struct pt_solution *pt;
varinfo_t vi, fi;
tree decl;
stmt = dyn_cast <gcall *> (gsi_stmt (gsi));
if (!stmt)
continue;
/* Handle direct calls to functions with body. */
decl = gimple_call_fndecl (stmt);
{
tree called_decl = NULL_TREE;
if (gimple_call_builtin_p (stmt, BUILT_IN_GOMP_PARALLEL))
called_decl = TREE_OPERAND (gimple_call_arg (stmt, 0), 0);
else if (gimple_call_builtin_p (stmt, BUILT_IN_GOACC_PARALLEL))
called_decl = TREE_OPERAND (gimple_call_arg (stmt, 1), 0);
if (called_decl != NULL_TREE
&& !fndecl_maybe_in_other_partition (called_decl))
decl = called_decl;
}
if (decl
&& (fi = lookup_vi_for_tree (decl))
&& fi->is_fn_info)
{
*gimple_call_clobber_set (stmt)
= find_what_var_points_to
(node->decl, first_vi_for_offset (fi, fi_clobbers));
*gimple_call_use_set (stmt)
= find_what_var_points_to
(node->decl, first_vi_for_offset (fi, fi_uses));
}
/* Handle direct calls to external functions. */
else if (decl && (!fi || fi->decl))
{
pt = gimple_call_use_set (stmt);
if (gimple_call_flags (stmt) & ECF_CONST)
memset (pt, 0, sizeof (struct pt_solution));
else if ((vi = lookup_call_use_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (node->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly used by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
always escaped. */
pt->nonlocal = 1;
pt->ipa_escaped = 1;
}
else
{
/* If there is nothing special about this call then
we have made everything that is used also escape. */
*pt = ipa_escaped_pt;
pt->nonlocal = 1;
}
pt = gimple_call_clobber_set (stmt);
if (gimple_call_flags (stmt) &
(ECF_CONST|ECF_PURE|ECF_NOVOPS))
memset (pt, 0, sizeof (struct pt_solution));
else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
{
*pt = find_what_var_points_to (node->decl, vi);
/* Escaped (and thus nonlocal) variables are always
implicitly clobbered by calls. */
/* ??? ESCAPED can be empty even though NONLOCAL
always escaped. */
pt->nonlocal = 1;
pt->ipa_escaped = 1;
}
else
{
/* If there is nothing special about this call then
we have made everything that is used also escape. */
*pt = ipa_escaped_pt;
pt->nonlocal = 1;
}
}
/* Handle indirect calls. */
else if ((fi = get_fi_for_callee (stmt)))
{
/* We need to accumulate all clobbers/uses of all possible
callees. */
fi = get_varinfo (var_rep[fi->id]);
/* If we cannot constrain the set of functions we'll end up
calling we end up using/clobbering everything. */
if (bitmap_bit_p (fi->solution, anything_id)
|| bitmap_bit_p (fi->solution, nonlocal_id)
|| bitmap_bit_p (fi->solution, escaped_id))
{
pt_solution_reset (gimple_call_clobber_set (stmt));
pt_solution_reset (gimple_call_use_set (stmt));
}
else
{
bitmap_iterator bi;
unsigned i;
struct pt_solution *uses, *clobbers;
uses = gimple_call_use_set (stmt);
clobbers = gimple_call_clobber_set (stmt);
memset (uses, 0, sizeof (struct pt_solution));
memset (clobbers, 0, sizeof (struct pt_solution));
EXECUTE_IF_SET_IN_BITMAP (fi->solution, 0, i, bi)
{
struct pt_solution sol;
vi = get_varinfo (i);
if (!vi->is_fn_info)
{
/* ??? We could be more precise here? */
uses->nonlocal = 1;
uses->ipa_escaped = 1;
clobbers->nonlocal = 1;
clobbers->ipa_escaped = 1;
continue;
}
if (!uses->anything)
{
sol = find_what_var_points_to
(node->decl,
first_vi_for_offset (vi, fi_uses));
pt_solution_ior_into (uses, &sol);
}
if (!clobbers->anything)
{
sol = find_what_var_points_to
(node->decl,
first_vi_for_offset (vi, fi_clobbers));
pt_solution_ior_into (clobbers, &sol);
}
}
}
}
else
gcc_unreachable ();
}
}
fn->gimple_df->ipa_pta = true;
/* We have to re-set the final-solution cache after each function
because what is a "global" is dependent on function context. */
final_solutions->empty ();
obstack_free (&final_solutions_obstack, NULL);
gcc_obstack_init (&final_solutions_obstack);
}
delete_points_to_sets ();
in_ipa_mode = 0;
return 0;
}
namespace {
const pass_data pass_data_ipa_pta =
{
SIMPLE_IPA_PASS, /* type */
"pta", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_IPA_PTA, /* tv_id */
0, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_ipa_pta : public simple_ipa_opt_pass
{
public:
pass_ipa_pta (gcc::context *ctxt)
: simple_ipa_opt_pass (pass_data_ipa_pta, ctxt)
{}
/* opt_pass methods: */
bool gate (function *) final override
{
return (optimize
&& flag_ipa_pta
/* Don't bother doing anything if the program has errors. */
&& !seen_error ());
}
opt_pass * clone () final override { return new pass_ipa_pta (m_ctxt); }
unsigned int execute (function *) final override
{
return ipa_pta_execute ();
}
}; // class pass_ipa_pta
} // anon namespace
simple_ipa_opt_pass *
make_pass_ipa_pta (gcc::context *ctxt)
{
return new pass_ipa_pta (ctxt);
}