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/****************************************************************************
* *
* GNAT COMPILER COMPONENTS *
* *
* U T I L S *
* *
* C Implementation File *
* *
* Copyright (C) 1992-2003, Free Software Foundation, Inc. *
* *
* GNAT is free software; you can redistribute it and/or modify it under *
* terms of the GNU General Public License as published by the Free Soft- *
* ware Foundation; either version 2, or (at your option) any later ver- *
* sion. GNAT is distributed in the hope that it will be useful, but WITH- *
* OUT 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 distributed with GNAT; see file COPYING. If not, write *
* to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
* MA 02111-1307, USA. *
* *
* GNAT was originally developed by the GNAT team at New York University. *
* Extensive contributions were provided by Ada Core Technologies Inc. *
* *
****************************************************************************/
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "flags.h"
#include "defaults.h"
#include "toplev.h"
#include "output.h"
#include "ggc.h"
#include "debug.h"
#include "convert.h"
#include "ada.h"
#include "types.h"
#include "atree.h"
#include "elists.h"
#include "namet.h"
#include "nlists.h"
#include "stringt.h"
#include "uintp.h"
#include "fe.h"
#include "sinfo.h"
#include "einfo.h"
#include "ada-tree.h"
#include "gigi.h"
#ifndef MAX_FIXED_MODE_SIZE
#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
#endif
#ifndef MAX_BITS_PER_WORD
#define MAX_BITS_PER_WORD BITS_PER_WORD
#endif
/* If nonzero, pretend we are allocating at global level. */
int force_global;
/* Tree nodes for the various types and decls we create. */
tree gnat_std_decls[(int) ADT_LAST];
/* Functions to call for each of the possible raise reasons. */
tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
/* Associates a GNAT tree node to a GCC tree node. It is used in
`save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
of `save_gnu_tree' for more info. */
static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu;
/* This listhead is used to record any global objects that need elaboration.
TREE_PURPOSE is the variable to be elaborated and TREE_VALUE is the
initial value to assign. */
static GTY(()) tree pending_elaborations;
/* This stack allows us to momentarily switch to generating elaboration
lists for an inner context. */
struct e_stack GTY(()) {
struct e_stack *next;
tree elab_list;
};
static GTY(()) struct e_stack *elist_stack;
/* This variable keeps a table for types for each precision so that we only
allocate each of them once. Signed and unsigned types are kept separate.
Note that these types are only used when fold-const requests something
special. Perhaps we should NOT share these types; we'll see how it
goes later. */
static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2];
/* Likewise for float types, but record these by mode. */
static GTY(()) tree float_types[NUM_MACHINE_MODES];
/* For each binding contour we allocate a binding_level structure which records
the entities defined or declared in that contour. Contours include:
the global one
one for each subprogram definition
one for each compound statement (declare block)
Binding contours are used to create GCC tree BLOCK nodes. */
struct binding_level GTY(())
{
/* A chain of ..._DECL nodes for all variables, constants, functions,
parameters and type declarations. These ..._DECL nodes are chained
through the TREE_CHAIN field. Note that these ..._DECL nodes are stored
in the reverse of the order supplied to be compatible with the
back-end. */
tree names;
/* For each level (except the global one), a chain of BLOCK nodes for all
the levels that were entered and exited one level down from this one. */
tree blocks;
/* The BLOCK node for this level, if one has been preallocated.
If 0, the BLOCK is allocated (if needed) when the level is popped. */
tree this_block;
/* The binding level containing this one (the enclosing binding level). */
struct binding_level *level_chain;
};
/* The binding level currently in effect. */
static GTY(()) struct binding_level *current_binding_level;
/* A chain of binding_level structures awaiting reuse. */
static GTY((deletable (""))) struct binding_level *free_binding_level;
/* The outermost binding level. This binding level is created when the
compiler is started and it will exist through the entire compilation. */
static struct binding_level *global_binding_level;
/* Binding level structures are initialized by copying this one. */
static struct binding_level clear_binding_level = {NULL, NULL, NULL, NULL};
struct language_function GTY(())
{
int unused;
};
static tree merge_sizes (tree, tree, tree, int, int);
static tree compute_related_constant (tree, tree);
static tree split_plus (tree, tree *);
static int value_zerop (tree);
static tree float_type_for_precision (int, enum machine_mode);
static tree convert_to_fat_pointer (tree, tree);
static tree convert_to_thin_pointer (tree, tree);
static tree make_descriptor_field (const char *,tree, tree, tree);
static int value_factor_p (tree, int);
static int potential_alignment_gap (tree, tree, tree);
/* Initialize the association of GNAT nodes to GCC trees. */
void
init_gnat_to_gnu (void)
{
associate_gnat_to_gnu
= (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
pending_elaborations = build_tree_list (NULL_TREE, NULL_TREE);
}
/* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree
which is to be associated with GNAT_ENTITY. Such GCC tree node is always
a ..._DECL node. If NO_CHECK is nonzero, the latter check is suppressed.
If GNU_DECL is zero, a previous association is to be reset. */
void
save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, int no_check)
{
/* Check that GNAT_ENTITY is not already defined and that it is being set
to something which is a decl. Raise gigi 401 if not. Usually, this
means GNAT_ENTITY is defined twice, but occasionally is due to some
Gigi problem. */
if (gnu_decl
&& (associate_gnat_to_gnu[gnat_entity - First_Node_Id]
|| (! no_check && ! DECL_P (gnu_decl))))
gigi_abort (401);
associate_gnat_to_gnu[gnat_entity - First_Node_Id] = gnu_decl;
}
/* GNAT_ENTITY is a GNAT tree node for a defining identifier.
Return the ..._DECL node that was associated with it. If there is no tree
node associated with GNAT_ENTITY, abort.
In some cases, such as delayed elaboration or expressions that need to
be elaborated only once, GNAT_ENTITY is really not an entity. */
tree
get_gnu_tree (Entity_Id gnat_entity)
{
if (! associate_gnat_to_gnu[gnat_entity - First_Node_Id])
gigi_abort (402);
return associate_gnat_to_gnu[gnat_entity - First_Node_Id];
}
/* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
int
present_gnu_tree (Entity_Id gnat_entity)
{
return (associate_gnat_to_gnu[gnat_entity - First_Node_Id] != NULL_TREE);
}
/* Return non-zero if we are currently in the global binding level. */
int
global_bindings_p (void)
{
return (force_global != 0 || current_binding_level == global_binding_level
? -1 : 0);
}
/* Return the list of declarations in the current level. Note that this list
is in reverse order (it has to be so for back-end compatibility). */
tree
getdecls (void)
{
return current_binding_level->names;
}
/* Nonzero if the current level needs to have a BLOCK made. */
int
kept_level_p (void)
{
return (current_binding_level->names != 0);
}
/* Enter a new binding level. The input parameter is ignored, but has to be
specified for back-end compatibility. */
void
pushlevel (int ignore ATTRIBUTE_UNUSED)
{
struct binding_level *newlevel = NULL;
/* Reuse a struct for this binding level, if there is one. */
if (free_binding_level)
{
newlevel = free_binding_level;
free_binding_level = free_binding_level->level_chain;
}
else
newlevel
= (struct binding_level *) ggc_alloc (sizeof (struct binding_level));
*newlevel = clear_binding_level;
/* Add this level to the front of the chain (stack) of levels that are
active. */
newlevel->level_chain = current_binding_level;
current_binding_level = newlevel;
}
/* Exit a binding level.
Pop the level off, and restore the state of the identifier-decl mappings
that were in effect when this level was entered.
If KEEP is nonzero, this level had explicit declarations, so
and create a "block" (a BLOCK node) for the level
to record its declarations and subblocks for symbol table output.
If FUNCTIONBODY is nonzero, this level is the body of a function,
so create a block as if KEEP were set and also clear out all
label names.
If REVERSE is nonzero, reverse the order of decls before putting
them into the BLOCK. */
tree
poplevel (int keep, int reverse, int functionbody)
{
/* Points to a GCC BLOCK tree node. This is the BLOCK node construted for the
binding level that we are about to exit and which is returned by this
routine. */
tree block = NULL_TREE;
tree decl_chain;
tree decl_node;
tree subblock_chain = current_binding_level->blocks;
tree subblock_node;
int block_previously_created;
/* Reverse the list of XXXX_DECL nodes if desired. Note that the ..._DECL
nodes chained through the `names' field of current_binding_level are in
reverse order except for PARM_DECL node, which are explicitly stored in
the right order. */
current_binding_level->names
= decl_chain = (reverse) ? nreverse (current_binding_level->names)
: current_binding_level->names;
/* Output any nested inline functions within this block which must be
compiled because their address is needed. */
for (decl_node = decl_chain; decl_node; decl_node = TREE_CHAIN (decl_node))
if (TREE_CODE (decl_node) == FUNCTION_DECL
&& ! TREE_ASM_WRITTEN (decl_node) && TREE_ADDRESSABLE (decl_node)
&& DECL_INITIAL (decl_node) != 0)
{
push_function_context ();
output_inline_function (decl_node);
pop_function_context ();
}
block = 0;
block_previously_created = (current_binding_level->this_block != 0);
if (block_previously_created)
block = current_binding_level->this_block;
else if (keep || functionbody)
block = make_node (BLOCK);
if (block != 0)
{
BLOCK_VARS (block) = keep ? decl_chain : 0;
BLOCK_SUBBLOCKS (block) = subblock_chain;
}
/* Record the BLOCK node just built as the subblock its enclosing scope. */
for (subblock_node = subblock_chain; subblock_node;
subblock_node = TREE_CHAIN (subblock_node))
BLOCK_SUPERCONTEXT (subblock_node) = block;
/* Clear out the meanings of the local variables of this level. */
for (subblock_node = decl_chain; subblock_node;
subblock_node = TREE_CHAIN (subblock_node))
if (DECL_NAME (subblock_node) != 0)
/* If the identifier was used or addressed via a local extern decl,
don't forget that fact. */
if (DECL_EXTERNAL (subblock_node))
{
if (TREE_USED (subblock_node))
TREE_USED (DECL_NAME (subblock_node)) = 1;
if (TREE_ADDRESSABLE (subblock_node))
TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (subblock_node)) = 1;
}
{
/* Pop the current level, and free the structure for reuse. */
struct binding_level *level = current_binding_level;
current_binding_level = current_binding_level->level_chain;
level->level_chain = free_binding_level;
free_binding_level = level;
}
if (functionbody)
{
/* This is the top level block of a function. The ..._DECL chain stored
in BLOCK_VARS are the function's parameters (PARM_DECL nodes). Don't
leave them in the BLOCK because they are found in the FUNCTION_DECL
instead. */
DECL_INITIAL (current_function_decl) = block;
BLOCK_VARS (block) = 0;
}
else if (block)
{
if (!block_previously_created)
current_binding_level->blocks
= chainon (current_binding_level->blocks, block);
}
/* If we did not make a block for the level just exited, any blocks made for
inner levels (since they cannot be recorded as subblocks in that level)
must be carried forward so they will later become subblocks of something
else. */
else if (subblock_chain)
current_binding_level->blocks
= chainon (current_binding_level->blocks, subblock_chain);
if (block)
TREE_USED (block) = 1;
return block;
}
/* Insert BLOCK at the end of the list of subblocks of the
current binding level. This is used when a BIND_EXPR is expanded,
to handle the BLOCK node inside the BIND_EXPR. */
void
insert_block (tree block)
{
TREE_USED (block) = 1;
current_binding_level->blocks
= chainon (current_binding_level->blocks, block);
}
/* Set the BLOCK node for the innermost scope
(the one we are currently in). */
void
set_block (tree block)
{
current_binding_level->this_block = block;
current_binding_level->names = chainon (current_binding_level->names,
BLOCK_VARS (block));
current_binding_level->blocks = chainon (current_binding_level->blocks,
BLOCK_SUBBLOCKS (block));
}
/* Records a ..._DECL node DECL as belonging to the current lexical scope.
Returns the ..._DECL node. */
tree
pushdecl (tree decl)
{
struct binding_level *b;
/* If at top level, there is no context. But PARM_DECLs always go in the
level of its function. */
if (global_bindings_p () && TREE_CODE (decl) != PARM_DECL)
{
b = global_binding_level;
DECL_CONTEXT (decl) = 0;
}
else
{
b = current_binding_level;
DECL_CONTEXT (decl) = current_function_decl;
}
/* Put the declaration on the list. The list of declarations is in reverse
order. The list will be reversed later if necessary. This needs to be
this way for compatibility with the back-end.
Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into the list. They
will cause trouble with the debugger and aren't needed anyway. */
if (TREE_CODE (decl) != TYPE_DECL
|| TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE)
{
TREE_CHAIN (decl) = b->names;
b->names = decl;
}
/* For the declaration of a type, set its name if it either is not already
set, was set to an IDENTIFIER_NODE, indicating an internal name,
or if the previous type name was not derived from a source name.
We'd rather have the type named with a real name and all the pointer
types to the same object have the same POINTER_TYPE node. Code in this
function in c-decl.c makes a copy of the type node here, but that may
cause us trouble with incomplete types, so let's not try it (at least
for now). */
if (TREE_CODE (decl) == TYPE_DECL
&& DECL_NAME (decl) != 0
&& (TYPE_NAME (TREE_TYPE (decl)) == 0
|| TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == IDENTIFIER_NODE
|| (TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == TYPE_DECL
&& DECL_ARTIFICIAL (TYPE_NAME (TREE_TYPE (decl)))
&& ! DECL_ARTIFICIAL (decl))))
TYPE_NAME (TREE_TYPE (decl)) = decl;
return decl;
}
/* Do little here. Set up the standard declarations later after the
front end has been run. */
void
gnat_init_decl_processing (void)
{
input_line = 0;
/* Make the binding_level structure for global names. */
current_function_decl = 0;
current_binding_level = 0;
free_binding_level = 0;
pushlevel (0);
global_binding_level = current_binding_level;
build_common_tree_nodes (0);
/* In Ada, we use a signed type for SIZETYPE. Use the signed type
corresponding to the size of Pmode. In most cases when ptr_mode and
Pmode differ, C will use the width of ptr_mode as sizetype. But we get
far better code using the width of Pmode. Make this here since we need
this before we can expand the GNAT types. */
set_sizetype (gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0));
build_common_tree_nodes_2 (0);
pushdecl (build_decl (TYPE_DECL, get_identifier (SIZE_TYPE), sizetype));
/* We need to make the integer type before doing anything else.
We stitch this in to the appropriate GNAT type later. */
pushdecl (build_decl (TYPE_DECL, get_identifier ("integer"),
integer_type_node));
pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"),
char_type_node));
ptr_void_type_node = build_pointer_type (void_type_node);
}
/* Create the predefined scalar types such as `integer_type_node' needed
in the gcc back-end and initialize the global binding level. */
void
init_gigi_decls (tree long_long_float_type, tree exception_type)
{
tree endlink, decl;
unsigned int i;
/* Set the types that GCC and Gigi use from the front end. We would like
to do this for char_type_node, but it needs to correspond to the C
char type. */
if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE)
{
/* In this case, the builtin floating point types are VAX float,
so make up a type for use. */
longest_float_type_node = make_node (REAL_TYPE);
TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE;
layout_type (longest_float_type_node);
pushdecl (build_decl (TYPE_DECL, get_identifier ("longest float type"),
longest_float_type_node));
}
else
longest_float_type_node = TREE_TYPE (long_long_float_type);
except_type_node = TREE_TYPE (exception_type);
unsigned_type_node = gnat_type_for_size (INT_TYPE_SIZE, 1);
pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned int"),
unsigned_type_node));
void_type_decl_node
= pushdecl (build_decl (TYPE_DECL, get_identifier ("void"),
void_type_node));
void_ftype = build_function_type (void_type_node, NULL_TREE);
ptr_void_ftype = build_pointer_type (void_ftype);
/* Now declare runtime functions. */
endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
/* malloc is a function declaration tree for a function to allocate
memory. */
malloc_decl = create_subprog_decl (get_identifier ("__gnat_malloc"),
NULL_TREE,
build_function_type (ptr_void_type_node,
tree_cons (NULL_TREE,
sizetype,
endlink)),
NULL_TREE, 0, 1, 1, 0);
/* free is a function declaration tree for a function to free memory. */
free_decl
= create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
ptr_void_type_node,
endlink)),
NULL_TREE, 0, 1, 1, 0);
/* Make the types and functions used for exception processing. */
jmpbuf_type
= build_array_type (gnat_type_for_mode (Pmode, 0),
build_index_type (build_int_2 (5, 0)));
pushdecl (build_decl (TYPE_DECL, get_identifier ("JMPBUF_T"), jmpbuf_type));
jmpbuf_ptr_type = build_pointer_type (jmpbuf_type);
/* Functions to get and set the jumpbuf pointer for the current thread. */
get_jmpbuf_decl
= create_subprog_decl
(get_identifier ("system__soft_links__get_jmpbuf_address_soft"),
NULL_TREE, build_function_type (jmpbuf_ptr_type, NULL_TREE),
NULL_TREE, 0, 1, 1, 0);
set_jmpbuf_decl
= create_subprog_decl
(get_identifier ("system__soft_links__set_jmpbuf_address_soft"),
NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
NULL_TREE, 0, 1, 1, 0);
/* Function to get the current exception. */
get_excptr_decl
= create_subprog_decl
(get_identifier ("system__soft_links__get_gnat_exception"),
NULL_TREE,
build_function_type (build_pointer_type (except_type_node), NULL_TREE),
NULL_TREE, 0, 1, 1, 0);
/* Functions that raise exceptions. */
raise_nodefer_decl
= create_subprog_decl
(get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
build_pointer_type (except_type_node),
endlink)),
NULL_TREE, 0, 1, 1, 0);
/* Hooks to call when entering/leaving an exception handler. */
begin_handler_decl
= create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
ptr_void_type_node,
endlink)),
NULL_TREE, 0, 1, 1, 0);
end_handler_decl
= create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
ptr_void_type_node,
endlink)),
NULL_TREE, 0, 1, 1, 0);
/* If in no exception handlers mode, all raise statements are redirected to
__gnat_last_chance_handler. No need to redefine raise_nodefer_decl, since
this procedure will never be called in this mode. */
if (No_Exception_Handlers_Set ())
{
decl
= create_subprog_decl
(get_identifier ("__gnat_last_chance_handler"), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
build_pointer_type (char_type_node),
tree_cons (NULL_TREE,
integer_type_node,
endlink))),
NULL_TREE, 0, 1, 1, 0);
for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
gnat_raise_decls[i] = decl;
}
else
/* Otherwise, make one decl for each exception reason. */
for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
{
char name[17];
sprintf (name, "__gnat_rcheck_%.2d", i);
gnat_raise_decls[i]
= create_subprog_decl
(get_identifier (name), NULL_TREE,
build_function_type (void_type_node,
tree_cons (NULL_TREE,
build_pointer_type
(char_type_node),
tree_cons (NULL_TREE,
integer_type_node,
endlink))),
NULL_TREE, 0, 1, 1, 0);
}
/* Indicate that these never return. */
TREE_THIS_VOLATILE (raise_nodefer_decl) = 1;
TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1;
TREE_TYPE (raise_nodefer_decl)
= build_qualified_type (TREE_TYPE (raise_nodefer_decl),
TYPE_QUAL_VOLATILE);
for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
{
TREE_THIS_VOLATILE (gnat_raise_decls[i]) = 1;
TREE_SIDE_EFFECTS (gnat_raise_decls[i]) = 1;
TREE_TYPE (gnat_raise_decls[i])
= build_qualified_type (TREE_TYPE (gnat_raise_decls[i]),
TYPE_QUAL_VOLATILE);
}
/* setjmp returns an integer and has one operand, which is a pointer to
a jmpbuf. */
setjmp_decl
= create_subprog_decl
(get_identifier ("__builtin_setjmp"), NULL_TREE,
build_function_type (integer_type_node,
tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
NULL_TREE, 0, 1, 1, 0);
DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL;
DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP;
main_identifier_node = get_identifier ("main");
}
/* Given a record type (RECORD_TYPE) and a chain of FIELD_DECL
nodes (FIELDLIST), finish constructing the record or union type.
If HAS_REP is nonzero, this record has a rep clause; don't call
layout_type but merely set the size and alignment ourselves.
If DEFER_DEBUG is nonzero, do not call the debugging routines
on this type; it will be done later. */
void
finish_record_type (tree record_type,
tree fieldlist,
int has_rep,
int defer_debug)
{
enum tree_code code = TREE_CODE (record_type);
tree ada_size = bitsize_zero_node;
tree size = bitsize_zero_node;
tree size_unit = size_zero_node;
int var_size = 0;
tree field;
TYPE_FIELDS (record_type) = fieldlist;
if (TYPE_NAME (record_type) != 0
&& TREE_CODE (TYPE_NAME (record_type)) == TYPE_DECL)
TYPE_STUB_DECL (record_type) = TYPE_NAME (record_type);
else
TYPE_STUB_DECL (record_type)
= pushdecl (build_decl (TYPE_DECL, TYPE_NAME (record_type),
record_type));
/* We don't need both the typedef name and the record name output in
the debugging information, since they are the same. */
DECL_ARTIFICIAL (TYPE_STUB_DECL (record_type)) = 1;
/* Globally initialize the record first. If this is a rep'ed record,
that just means some initializations; otherwise, layout the record. */
if (has_rep)
{
TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type));
TYPE_MODE (record_type) = BLKmode;
if (TYPE_SIZE (record_type) == 0)
{
TYPE_SIZE (record_type) = bitsize_zero_node;
TYPE_SIZE_UNIT (record_type) = size_zero_node;
}
/* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
out just like a UNION_TYPE, since the size will be fixed. */
else if (code == QUAL_UNION_TYPE)
code = UNION_TYPE;
}
else
{
/* Ensure there isn't a size already set. There can be in an error
case where there is a rep clause but all fields have errors and
no longer have a position. */
TYPE_SIZE (record_type) = 0;
layout_type (record_type);
}
/* At this point, the position and size of each field is known. It was
either set before entry by a rep clause, or by laying out the type
above. We now make a pass through the fields (in reverse order for
QUAL_UNION_TYPEs) to compute the Ada size; the GCC size and alignment
(for rep'ed records that are not padding types); and the mode (for
rep'ed records). */
if (code == QUAL_UNION_TYPE)
fieldlist = nreverse (fieldlist);
for (field = fieldlist; field; field = TREE_CHAIN (field))
{
tree type = TREE_TYPE (field);
tree this_size = DECL_SIZE (field);
tree this_size_unit = DECL_SIZE_UNIT (field);
tree this_ada_size = DECL_SIZE (field);
/* We need to make an XVE/XVU record if any field has variable size,
whether or not the record does. For example, if we have an union,
it may be that all fields, rounded up to the alignment, have the
same size, in which case we'll use that size. But the debug
output routines (except Dwarf2) won't be able to output the fields,
so we need to make the special record. */
if (TREE_CODE (this_size) != INTEGER_CST)
var_size = 1;
if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
|| TREE_CODE (type) == QUAL_UNION_TYPE)
&& ! TYPE_IS_FAT_POINTER_P (type)
&& ! TYPE_CONTAINS_TEMPLATE_P (type)
&& TYPE_ADA_SIZE (type) != 0)
this_ada_size = TYPE_ADA_SIZE (type);
if (has_rep && ! DECL_BIT_FIELD (field))
TYPE_ALIGN (record_type)
= MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field));
switch (code)
{
case UNION_TYPE:
ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size);
size = size_binop (MAX_EXPR, size, this_size);
size_unit = size_binop (MAX_EXPR, size_unit, this_size_unit);
break;
case QUAL_UNION_TYPE:
ada_size
= fold (build (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
this_ada_size, ada_size));
size = fold (build (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
this_size, size));
size_unit = fold (build (COND_EXPR, sizetype, DECL_QUALIFIER (field),
this_size_unit, size_unit));
break;
case RECORD_TYPE:
/* Since we know here that all fields are sorted in order of
increasing bit position, the size of the record is one
higher than the ending bit of the last field processed
unless we have a rep clause, since in that case we might
have a field outside a QUAL_UNION_TYPE that has a higher ending
position. So use a MAX in that case. Also, if this field is a
QUAL_UNION_TYPE, we need to take into account the previous size in
the case of empty variants. */
ada_size
= merge_sizes (ada_size, bit_position (field), this_ada_size,
TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
size = merge_sizes (size, bit_position (field), this_size,
TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
size_unit
= merge_sizes (size_unit, byte_position (field), this_size_unit,
TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
break;
default:
abort ();
}
}
if (code == QUAL_UNION_TYPE)
nreverse (fieldlist);
/* If this is a padding record, we never want to make the size smaller than
what was specified in it, if any. */
if (TREE_CODE (record_type) == RECORD_TYPE
&& TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type) != 0)
{
size = TYPE_SIZE (record_type);
size_unit = TYPE_SIZE_UNIT (record_type);
}
/* Now set any of the values we've just computed that apply. */
if (! TYPE_IS_FAT_POINTER_P (record_type)
&& ! TYPE_CONTAINS_TEMPLATE_P (record_type))
SET_TYPE_ADA_SIZE (record_type, ada_size);
if (has_rep)
{
if (! (TREE_CODE (record_type) == RECORD_TYPE
&& TYPE_IS_PADDING_P (record_type)
&& CONTAINS_PLACEHOLDER_P (size)))
{
TYPE_SIZE (record_type) = round_up (size, TYPE_ALIGN (record_type));
TYPE_SIZE_UNIT (record_type)
= round_up (size_unit,
TYPE_ALIGN (record_type) / BITS_PER_UNIT);
}
compute_record_mode (record_type);
}
if (! defer_debug)
{
/* If this record is of variable size, rename it so that the
debugger knows it is and make a new, parallel, record
that tells the debugger how the record is laid out. See
exp_dbug.ads. But don't do this for records that are padding
since they confuse GDB. */
if (var_size
&& ! (TREE_CODE (record_type) == RECORD_TYPE
&& TYPE_IS_PADDING_P (record_type)))
{
tree new_record_type
= make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE
? UNION_TYPE : TREE_CODE (record_type));
tree orig_id = DECL_NAME (TYPE_STUB_DECL (record_type));
tree new_id
= concat_id_with_name (orig_id,
TREE_CODE (record_type) == QUAL_UNION_TYPE
? "XVU" : "XVE");
tree last_pos = bitsize_zero_node;
tree old_field;
tree prev_old_field = 0;
TYPE_NAME (new_record_type) = new_id;
TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT;
TYPE_STUB_DECL (new_record_type)
= pushdecl (build_decl (TYPE_DECL, new_id, new_record_type));
DECL_ARTIFICIAL (TYPE_STUB_DECL (new_record_type)) = 1;
DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type))
= DECL_IGNORED_P (TYPE_STUB_DECL (record_type));
TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type));
/* Now scan all the fields, replacing each field with a new
field corresponding to the new encoding. */
for (old_field = TYPE_FIELDS (record_type); old_field != 0;
old_field = TREE_CHAIN (old_field))
{
tree field_type = TREE_TYPE (old_field);
tree field_name = DECL_NAME (old_field);
tree new_field;
tree curpos = bit_position (old_field);
int var = 0;
unsigned int align = 0;
tree pos;
/* See how the position was modified from the last position.
There are two basic cases we support: a value was added
to the last position or the last position was rounded to
a boundary and they something was added. Check for the
first case first. If not, see if there is any evidence
of rounding. If so, round the last position and try
again.
If this is a union, the position can be taken as zero. */
if (TREE_CODE (new_record_type) == UNION_TYPE)
pos = bitsize_zero_node, align = 0;
else
pos = compute_related_constant (curpos, last_pos);
if (pos == 0 && TREE_CODE (curpos) == MULT_EXPR
&& TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST)
{
align = TREE_INT_CST_LOW (TREE_OPERAND (curpos, 1));
pos = compute_related_constant (curpos,
round_up (last_pos, align));
}
else if (pos == 0 && TREE_CODE (curpos) == PLUS_EXPR
&& TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR
&& host_integerp (TREE_OPERAND
(TREE_OPERAND (curpos, 0), 1),
1))
{
align
= tree_low_cst
(TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1);
pos = compute_related_constant (curpos,
round_up (last_pos, align));
}
else if (potential_alignment_gap (prev_old_field, old_field,
pos))
{
align = TYPE_ALIGN (field_type);
pos = compute_related_constant (curpos,
round_up (last_pos, align));
}
/* If we can't compute a position, set it to zero.
??? We really should abort here, but it's too much work
to get this correct for all cases. */
if (pos == 0)
pos = bitsize_zero_node;
/* See if this type is variable-size and make a new type
and indicate the indirection if so. */
if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST)
{
field_type = build_pointer_type (field_type);
var = 1;
}
/* Make a new field name, if necessary. */
if (var || align != 0)
{
char suffix[6];
if (align != 0)
sprintf (suffix, "XV%c%u", var ? 'L' : 'A',
align / BITS_PER_UNIT);
else
strcpy (suffix, "XVL");
field_name = concat_id_with_name (field_name, suffix);
}
new_field = create_field_decl (field_name, field_type,
new_record_type, 0,
DECL_SIZE (old_field), pos, 0);
TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type);
TYPE_FIELDS (new_record_type) = new_field;
/* If old_field is a QUAL_UNION_TYPE, take its size as being
zero. The only time it's not the last field of the record
is when there are other components at fixed positions after
it (meaning there was a rep clause for every field) and we
want to be able to encode them. */
last_pos = size_binop (PLUS_EXPR, bit_position (old_field),
(TREE_CODE (TREE_TYPE (old_field))
== QUAL_UNION_TYPE)
? bitsize_zero_node
: DECL_SIZE (old_field));
prev_old_field = old_field;
}
TYPE_FIELDS (new_record_type)
= nreverse (TYPE_FIELDS (new_record_type));
rest_of_type_compilation (new_record_type, global_bindings_p ());
}
rest_of_type_compilation (record_type, global_bindings_p ());
}
}
/* Utility function of above to merge LAST_SIZE, the previous size of a record
with FIRST_BIT and SIZE that describe a field. SPECIAL is nonzero
if this represents a QUAL_UNION_TYPE in which case we must look for
COND_EXPRs and replace a value of zero with the old size. If HAS_REP
is nonzero, we must take the MAX of the end position of this field
with LAST_SIZE. In all other cases, we use FIRST_BIT plus SIZE.
We return an expression for the size. */
static tree
merge_sizes (tree last_size,
tree first_bit,
tree size,
int special,
int has_rep)
{
tree type = TREE_TYPE (last_size);
tree new;
if (! special || TREE_CODE (size) != COND_EXPR)
{
new = size_binop (PLUS_EXPR, first_bit, size);
if (has_rep)
new = size_binop (MAX_EXPR, last_size, new);
}
else
new = fold (build (COND_EXPR, type, TREE_OPERAND (size, 0),
integer_zerop (TREE_OPERAND (size, 1))
? last_size : merge_sizes (last_size, first_bit,
TREE_OPERAND (size, 1),
1, has_rep),
integer_zerop (TREE_OPERAND (size, 2))
? last_size : merge_sizes (last_size, first_bit,
TREE_OPERAND (size, 2),
1, has_rep)));
/* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
when fed through substitute_in_expr) into thinking that a constant
size is not constant. */
while (TREE_CODE (new) == NON_LVALUE_EXPR)
new = TREE_OPERAND (new, 0);
return new;
}
/* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
related by the addition of a constant. Return that constant if so. */
static tree
compute_related_constant (tree op0, tree op1)
{
tree op0_var, op1_var;
tree op0_con = split_plus (op0, &op0_var);
tree op1_con = split_plus (op1, &op1_var);
tree result = size_binop (MINUS_EXPR, op0_con, op1_con);
if (operand_equal_p (op0_var, op1_var, 0))
return result;
else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0))
return result;
else
return 0;
}
/* Utility function of above to split a tree OP which may be a sum, into a
constant part, which is returned, and a variable part, which is stored
in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
bitsizetype. */
static tree
split_plus (tree in, tree *pvar)
{
/* Strip NOPS in order to ease the tree traversal and maximize the
potential for constant or plus/minus discovery. We need to be careful
to always return and set *pvar to bitsizetype trees, but it's worth
the effort. */
STRIP_NOPS (in);
*pvar = convert (bitsizetype, in);
if (TREE_CODE (in) == INTEGER_CST)
{
*pvar = bitsize_zero_node;
return convert (bitsizetype, in);
}
else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR)
{
tree lhs_var, rhs_var;
tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var);
tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var);
if (lhs_var == TREE_OPERAND (in, 0)
&& rhs_var == TREE_OPERAND (in, 1))
return bitsize_zero_node;
*pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var);
return size_binop (TREE_CODE (in), lhs_con, rhs_con);
}
else
return bitsize_zero_node;
}
/* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
subprogram. If it is void_type_node, then we are dealing with a procedure,
otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the
copy-in/copy-out list to be stored into TYPE_CICO_LIST.
RETURNS_UNCONSTRAINED is nonzero if the function returns an unconstrained
object. RETURNS_BY_REF is nonzero if the function returns by reference.
RETURNS_WITH_DSP is nonzero if the function is to return with a
depressed stack pointer. */
tree
create_subprog_type (tree return_type,
tree param_decl_list,
tree cico_list,
int returns_unconstrained,
int returns_by_ref,
int returns_with_dsp)
{
/* A chain of TREE_LIST nodes whose TREE_VALUEs are the data type nodes of
the subprogram formal parameters. This list is generated by traversing the
input list of PARM_DECL nodes. */
tree param_type_list = NULL;
tree param_decl;
tree type;
for (param_decl = param_decl_list; param_decl;
param_decl = TREE_CHAIN (param_decl))
param_type_list = tree_cons (NULL_TREE, TREE_TYPE (param_decl),
param_type_list);
/* The list of the function parameter types has to be terminated by the void
type to signal to the back-end that we are not dealing with a variable
parameter subprogram, but that the subprogram has a fixed number of
parameters. */
param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list);
/* The list of argument types has been created in reverse
so nreverse it. */
param_type_list = nreverse (param_type_list);
type = build_function_type (return_type, param_type_list);
/* TYPE may have been shared since GCC hashes types. If it has a CICO_LIST
or the new type should, make a copy of TYPE. Likewise for
RETURNS_UNCONSTRAINED and RETURNS_BY_REF. */
if (TYPE_CI_CO_LIST (type) != 0 || cico_list != 0
|| TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained
|| TYPE_RETURNS_BY_REF_P (type) != returns_by_ref)
type = copy_type (type);
SET_TYPE_CI_CO_LIST (type, cico_list);
TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained;
TYPE_RETURNS_STACK_DEPRESSED (type) = returns_with_dsp;
TYPE_RETURNS_BY_REF_P (type) = returns_by_ref;
return type;
}
/* Return a copy of TYPE but safe to modify in any way. */
tree
copy_type (tree type)
{
tree new = copy_node (type);
/* copy_node clears this field instead of copying it, because it is
aliased with TREE_CHAIN. */
TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type);
TYPE_POINTER_TO (new) = 0;
TYPE_REFERENCE_TO (new) = 0;
TYPE_MAIN_VARIANT (new) = new;
TYPE_NEXT_VARIANT (new) = 0;
return new;
}
/* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
TYPE_INDEX_TYPE is INDEX. */
tree
create_index_type (tree min, tree max, tree index)
{
/* First build a type for the desired range. */
tree type = build_index_2_type (min, max);
/* If this type has the TYPE_INDEX_TYPE we want, return it. Otherwise, if it
doesn't have TYPE_INDEX_TYPE set, set it to INDEX. If TYPE_INDEX_TYPE
is set, but not to INDEX, make a copy of this type with the requested
index type. Note that we have no way of sharing these types, but that's
only a small hole. */
if (TYPE_INDEX_TYPE (type) == index)
return type;
else if (TYPE_INDEX_TYPE (type) != 0)
type = copy_type (type);
SET_TYPE_INDEX_TYPE (type, index);
return type;
}
/* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character
string) and TYPE is a ..._TYPE node giving its data type.
ARTIFICIAL_P is nonzero if this is a declaration that was generated
by the compiler. DEBUG_INFO_P is nonzero if we need to write debugging
information about this type. */
tree
create_type_decl (tree type_name,
tree type,
struct attrib *attr_list,
int artificial_p,
int debug_info_p)
{
tree type_decl = build_decl (TYPE_DECL, type_name, type);
enum tree_code code = TREE_CODE (type);
DECL_ARTIFICIAL (type_decl) = artificial_p;
pushdecl (type_decl);
process_attributes (type_decl, attr_list);
/* Pass type declaration information to the debugger unless this is an
UNCONSTRAINED_ARRAY_TYPE, which the debugger does not support,
and ENUMERAL_TYPE or RECORD_TYPE which is handled separately,
a dummy type, which will be completed later, or a type for which
debugging information was not requested. */
if (code == UNCONSTRAINED_ARRAY_TYPE || TYPE_IS_DUMMY_P (type)
|| ! debug_info_p)
DECL_IGNORED_P (type_decl) = 1;
else if (code != ENUMERAL_TYPE && code != RECORD_TYPE
&& ! ((code == POINTER_TYPE || code == REFERENCE_TYPE)
&& TYPE_IS_DUMMY_P (TREE_TYPE (type))))
rest_of_decl_compilation (type_decl, NULL, global_bindings_p (), 0);
return type_decl;
}
/* Returns a GCC VAR_DECL node. VAR_NAME gives the name of the variable.
ASM_NAME is its assembler name (if provided). TYPE is its data type
(a GCC ..._TYPE node). VAR_INIT is the GCC tree for an optional initial
expression; NULL_TREE if none.
CONST_FLAG is nonzero if this variable is constant.
PUBLIC_FLAG is nonzero if this definition is to be made visible outside of
the current compilation unit. This flag should be set when processing the
variable definitions in a package specification. EXTERN_FLAG is nonzero
when processing an external variable declaration (as opposed to a
definition: no storage is to be allocated for the variable here).
STATIC_FLAG is only relevant when not at top level. In that case
it indicates whether to always allocate storage to the variable. */
tree
create_var_decl (tree var_name,
tree asm_name,
tree type,
tree var_init,
int const_flag,
int public_flag,
int extern_flag,
int static_flag,
struct attrib *attr_list)
{
int init_const
= (var_init == 0
? 0
: (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
&& (global_bindings_p () || static_flag
? 0 != initializer_constant_valid_p (var_init,
TREE_TYPE (var_init))
: TREE_CONSTANT (var_init))));
tree var_decl
= build_decl ((const_flag && init_const
/* Only make a CONST_DECL for sufficiently-small objects.
We consider complex double "sufficiently-small" */
&& TYPE_SIZE (type) != 0
&& host_integerp (TYPE_SIZE_UNIT (type), 1)
&& 0 >= compare_tree_int (TYPE_SIZE_UNIT (type),
GET_MODE_SIZE (DCmode)))
? CONST_DECL : VAR_DECL, var_name, type);
tree assign_init = 0;
/* If this is external, throw away any initializations unless this is a
CONST_DECL (meaning we have a constant); they will be done elsewhere. If
we are defining a global here, leave a constant initialization and save
any variable elaborations for the elaboration routine. Otherwise, if
the initializing expression is not the same as TYPE, generate the
initialization with an assignment statement, since it knows how
to do the required adjustents. If we are just annotating types,
throw away the initialization if it isn't a constant. */
if ((extern_flag && TREE_CODE (var_decl) != CONST_DECL)
|| (type_annotate_only && var_init != 0 && ! TREE_CONSTANT (var_init)))
var_init = 0;
if (global_bindings_p () && var_init != 0 && ! init_const)
{
add_pending_elaborations (var_decl, var_init);
var_init = 0;
}
else if (var_init != 0
&& ((TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
!= TYPE_MAIN_VARIANT (type))
|| (static_flag && ! init_const)))
assign_init = var_init, var_init = 0;
DECL_COMMON (var_decl) = !flag_no_common;
DECL_INITIAL (var_decl) = var_init;
TREE_READONLY (var_decl) = const_flag;
DECL_EXTERNAL (var_decl) = extern_flag;
TREE_PUBLIC (var_decl) = public_flag || extern_flag;
TREE_CONSTANT (var_decl) = TREE_CODE (var_decl) == CONST_DECL;
TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl)
= TYPE_VOLATILE (type);
/* At the global binding level we need to allocate static storage for the
variable if and only if its not external. If we are not at the top level
we allocate automatic storage unless requested not to. */
TREE_STATIC (var_decl) = global_bindings_p () ? !extern_flag : static_flag;
if (asm_name != 0)
SET_DECL_ASSEMBLER_NAME (var_decl, asm_name);
process_attributes (var_decl, attr_list);
/* Add this decl to the current binding level and generate any
needed code and RTL. */
var_decl = pushdecl (var_decl);
expand_decl (var_decl);
if (DECL_CONTEXT (var_decl) != 0)
expand_decl_init (var_decl);
/* If this is volatile, force it into memory. */
if (TREE_SIDE_EFFECTS (var_decl))
gnat_mark_addressable (var_decl);
if (TREE_CODE (var_decl) != CONST_DECL)
rest_of_decl_compilation (var_decl, 0, global_bindings_p (), 0);
if (assign_init != 0)
{
/* If VAR_DECL has a padded type, convert it to the unpadded
type so the assignment is done properly. */
tree lhs = var_decl;
if (TREE_CODE (TREE_TYPE (lhs)) == RECORD_TYPE
&& TYPE_IS_PADDING_P (TREE_TYPE (lhs)))
lhs = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (lhs))), lhs);
expand_expr_stmt (build_binary_op (MODIFY_EXPR, NULL_TREE, lhs,
assign_init));
}
return var_decl;
}
/* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if
this field is in a record type with a "pragma pack". If SIZE is nonzero
it is the specified size for this field. If POS is nonzero, it is the bit
position. If ADDRESSABLE is nonzero, it means we are allowed to take
the address of this field for aliasing purposes. */
tree
create_field_decl (tree field_name,
tree field_type,
tree record_type,
int packed,
tree size,
tree pos,
int addressable)
{
tree field_decl = build_decl (FIELD_DECL, field_name, field_type);
DECL_CONTEXT (field_decl) = record_type;
TREE_READONLY (field_decl) = TREE_READONLY (field_type);
/* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
byte boundary since GCC cannot handle less-aligned BLKmode bitfields. */
if (packed && TYPE_MODE (field_type) == BLKmode)
DECL_ALIGN (field_decl) = BITS_PER_UNIT;
/* If a size is specified, use it. Otherwise, see if we have a size
to use that may differ from the natural size of the object. */
if (size != 0)
size = convert (bitsizetype, size);
else if (packed)
{
if (packed == 1 && ! operand_equal_p (rm_size (field_type),
TYPE_SIZE (field_type), 0))
size = rm_size (field_type);
/* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
byte. */
if (size != 0 && TREE_CODE (size) == INTEGER_CST
&& compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
size = round_up (size, BITS_PER_UNIT);
}
/* Make a bitfield if a size is specified for two reasons: first if the size
differs from the natural size. Second, if the alignment is insufficient.
There are a number of ways the latter can be true. But never make a
bitfield if the type of the field has a nonconstant size. */
if (size != 0 && TREE_CODE (size) == INTEGER_CST
&& TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST
&& (! operand_equal_p (TYPE_SIZE (field_type), size, 0)
|| (pos != 0
&& ! value_zerop (size_binop (TRUNC_MOD_EXPR, pos,
bitsize_int (TYPE_ALIGN
(field_type)))))
|| packed
|| (TYPE_ALIGN (record_type) != 0
&& TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type))))
{
DECL_BIT_FIELD (field_decl) = 1;
DECL_SIZE (field_decl) = size;
if (! packed && pos == 0)
DECL_ALIGN (field_decl)
= (TYPE_ALIGN (record_type) != 0
? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type))
: TYPE_ALIGN (field_type));
}
DECL_PACKED (field_decl) = pos != 0 ? DECL_BIT_FIELD (field_decl) : packed;
DECL_ALIGN (field_decl)
= MAX (DECL_ALIGN (field_decl),
DECL_BIT_FIELD (field_decl) ? 1
: packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT
: TYPE_ALIGN (field_type));
if (pos != 0)
{
/* We need to pass in the alignment the DECL is known to have.
This is the lowest-order bit set in POS, but no more than
the alignment of the record, if one is specified. Note
that an alignment of 0 is taken as infinite. */
unsigned int known_align;
if (host_integerp (pos, 1))
known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1);
else
known_align = BITS_PER_UNIT;
if (TYPE_ALIGN (record_type)
&& (known_align == 0 || known_align > TYPE_ALIGN (record_type)))
known_align = TYPE_ALIGN (record_type);
layout_decl (field_decl, known_align);
SET_DECL_OFFSET_ALIGN (field_decl,
host_integerp (pos, 1) ? BIGGEST_ALIGNMENT
: BITS_PER_UNIT);
pos_from_bit (&DECL_FIELD_OFFSET (field_decl),
&DECL_FIELD_BIT_OFFSET (field_decl),
DECL_OFFSET_ALIGN (field_decl), pos);
DECL_HAS_REP_P (field_decl) = 1;
}
/* If the field type is passed by reference, we will have pointers to the
field, so it is addressable. */
if (must_pass_by_ref (field_type) || default_pass_by_ref (field_type))
addressable = 1;
/* ??? For now, we say that any field of aggregate type is addressable
because the front end may take 'Reference of it. */
if (AGGREGATE_TYPE_P (field_type))
addressable = 1;
/* Mark the decl as nonaddressable if it either is indicated so semantically
or if it is a bit field. */
DECL_NONADDRESSABLE_P (field_decl)
= ! addressable || DECL_BIT_FIELD (field_decl);
return field_decl;
}
/* Subroutine of previous function: return nonzero if EXP, ignoring any side
effects, has the value of zero. */
static int
value_zerop (tree exp)
{
if (TREE_CODE (exp) == COMPOUND_EXPR)
return value_zerop (TREE_OPERAND (exp, 1));
return integer_zerop (exp);
}
/* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
PARAM_TYPE is its type. READONLY is nonzero if the parameter is
readonly (either an IN parameter or an address of a pass-by-ref
parameter). */
tree
create_param_decl (tree param_name, tree param_type, int readonly)
{
tree param_decl = build_decl (PARM_DECL, param_name, param_type);
/* Honor the PROMOTE_PROTOTYPES target macro, as not doing so can
lead to various ABI violations. */
#ifdef PROMOTE_PROTOTYPES
if ((TREE_CODE (param_type) == INTEGER_TYPE
|| TREE_CODE (param_type) == ENUMERAL_TYPE)
&& TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
{
/* We have to be careful about biased types here. Make a subtype
of integer_type_node with the proper biasing. */
if (TREE_CODE (param_type) == INTEGER_TYPE
&& TYPE_BIASED_REPRESENTATION_P (param_type))
{
param_type
= copy_type (build_range_type (integer_type_node,
TYPE_MIN_VALUE (param_type),
TYPE_MAX_VALUE (param_type)));
TYPE_BIASED_REPRESENTATION_P (param_type) = 1;
}
else
param_type = integer_type_node;
}
#endif
DECL_ARG_TYPE (param_decl) = param_type;
DECL_ARG_TYPE_AS_WRITTEN (param_decl) = param_type;
TREE_READONLY (param_decl) = readonly;
return param_decl;
}
/* Given a DECL and ATTR_LIST, process the listed attributes. */
void
process_attributes (tree decl, struct attrib *attr_list)
{
for (; attr_list; attr_list = attr_list->next)
switch (attr_list->type)
{
case ATTR_MACHINE_ATTRIBUTE:
decl_attributes (&decl, tree_cons (attr_list->name, attr_list->arg,
NULL_TREE),
ATTR_FLAG_TYPE_IN_PLACE);
break;
case ATTR_LINK_ALIAS:
TREE_STATIC (decl) = 1;
assemble_alias (decl, attr_list->name);
break;
case ATTR_WEAK_EXTERNAL:
if (SUPPORTS_WEAK)
declare_weak (decl);
else
post_error ("?weak declarations not supported on this target",
attr_list->error_point);
break;
case ATTR_LINK_SECTION:
#ifdef ASM_OUTPUT_SECTION_NAME
DECL_SECTION_NAME (decl)
= build_string (IDENTIFIER_LENGTH (attr_list->name),
IDENTIFIER_POINTER (attr_list->name));
DECL_COMMON (decl) = 0;
#else
post_error ("?section attributes are not supported for this target",
attr_list->error_point);
#endif
break;
}
}
/* Add some pending elaborations on the list. */
void
add_pending_elaborations (tree var_decl, tree var_init)
{
if (var_init != 0)
Check_Elaboration_Code_Allowed (error_gnat_node);
pending_elaborations
= chainon (pending_elaborations, build_tree_list (var_decl, var_init));
}
/* Obtain any pending elaborations and clear the old list. */
tree
get_pending_elaborations (void)
{
/* Each thing added to the list went on the end; we want it on the
beginning. */
tree result = TREE_CHAIN (pending_elaborations);
TREE_CHAIN (pending_elaborations) = 0;
return result;
}
/* Return true if VALUE is a multiple of FACTOR. FACTOR must be a power
of 2. */
static int
value_factor_p (tree value, int factor)
{
if (host_integerp (value, 1))
return tree_low_cst (value, 1) % factor == 0;
if (TREE_CODE (value) == MULT_EXPR)
return (value_factor_p (TREE_OPERAND (value, 0), factor)
|| value_factor_p (TREE_OPERAND (value, 1), factor));
return 0;
}
/* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true
unless we can prove these 2 fields are laid out in such a way that no gap
exist between the end of PREV_FIELD and the begining of CURR_FIELD. OFFSET
is the distance in bits between the end of PREV_FIELD and the starting
position of CURR_FIELD. It is ignored if null. */
static int
potential_alignment_gap (tree prev_field, tree curr_field, tree offset)
{
/* If this is the first field of the record, there cannot be any gap */
if (!prev_field)
return 0;
/* If the previous field is a union type, then return False: The only
time when such a field is not the last field of the record is when
there are other components at fixed positions after it (meaning there
was a rep clause for every field), in which case we don't want the
alignment constraint to override them. */
if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE)
return 0;
/* If the distance between the end of prev_field and the begining of
curr_field is constant, then there is a gap if the value of this
constant is not null. */
if (offset && host_integerp (offset, 1))
return (!integer_zerop (offset));
/* If the size and position of the previous field are constant,
then check the sum of this size and position. There will be a gap
iff it is not multiple of the current field alignment. */
if (host_integerp (DECL_SIZE (prev_field), 1)
&& host_integerp (bit_position (prev_field), 1))
return ((tree_low_cst (bit_position (prev_field), 1)
+ tree_low_cst (DECL_SIZE (prev_field), 1))
% DECL_ALIGN (curr_field) != 0);
/* If both the position and size of the previous field are multiples
of the current field alignment, there can not be any gap. */
if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field))
&& value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field)))
return 0;
/* Fallback, return that there may be a potential gap */
return 1;
}
/* Return nonzero if there are pending elaborations. */
int
pending_elaborations_p (void)
{
return TREE_CHAIN (pending_elaborations) != 0;
}
/* Save a copy of the current pending elaboration list and make a new
one. */
void
push_pending_elaborations (void)
{
struct e_stack *p = (struct e_stack *) ggc_alloc (sizeof (struct e_stack));
p->next = elist_stack;
p->elab_list = pending_elaborations;
elist_stack = p;
pending_elaborations = build_tree_list (NULL_TREE, NULL_TREE);
}
/* Pop the stack of pending elaborations. */
void
pop_pending_elaborations (void)
{
struct e_stack *p = elist_stack;
pending_elaborations = p->elab_list;
elist_stack = p->next;
}
/* Return the current position in pending_elaborations so we can insert
elaborations after that point. */
tree
get_elaboration_location (void)
{
return tree_last (pending_elaborations);
}
/* Insert the current elaborations after ELAB, which is in some elaboration
list. */
void
insert_elaboration_list (tree elab)
{
tree next = TREE_CHAIN (elab);
if (TREE_CHAIN (pending_elaborations))
{
TREE_CHAIN (elab) = TREE_CHAIN (pending_elaborations);
TREE_CHAIN (tree_last (pending_elaborations)) = next;
TREE_CHAIN (pending_elaborations) = 0;
}
}
/* Returns a LABEL_DECL node for LABEL_NAME. */
tree
create_label_decl (tree label_name)
{
tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node);
DECL_CONTEXT (label_decl) = current_function_decl;
DECL_MODE (label_decl) = VOIDmode;
DECL_SOURCE_LOCATION (label_decl) = input_location;
return label_decl;
}
/* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram,
ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
PARM_DECL nodes chained through the TREE_CHAIN field).
INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
appropriate fields in the FUNCTION_DECL. */
tree
create_subprog_decl (tree subprog_name,
tree asm_name,
tree subprog_type,
tree param_decl_list,
int inline_flag,
int public_flag,
int extern_flag,
struct attrib *attr_list)
{
tree return_type = TREE_TYPE (subprog_type);
tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type);
/* If this is a function nested inside an inlined external function, it
means we aren't going to compile the outer function unless it is
actually inlined, so do the same for us. */
if (current_function_decl != 0 && DECL_INLINE (current_function_decl)
&& DECL_EXTERNAL (current_function_decl))
extern_flag = 1;
DECL_EXTERNAL (subprog_decl) = extern_flag;
TREE_PUBLIC (subprog_decl) = public_flag;
DECL_INLINE (subprog_decl) = inline_flag;
TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type);
TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type);
TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type);
DECL_ARGUMENTS (subprog_decl) = param_decl_list;
DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type);
if (asm_name != 0)
SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name);
process_attributes (subprog_decl, attr_list);
/* Add this decl to the current binding level. */
subprog_decl = pushdecl (subprog_decl);
/* Output the assembler code and/or RTL for the declaration. */
rest_of_decl_compilation (subprog_decl, 0, global_bindings_p (), 0);
return subprog_decl;
}
/* Count how deep we are into nested functions. This is because
we shouldn't call the backend function context routines unless we
are in a nested function. */
static int function_nesting_depth;
/* Set up the framework for generating code for SUBPROG_DECL, a subprogram
body. This routine needs to be invoked before processing the declarations
appearing in the subprogram. */
void
begin_subprog_body (tree subprog_decl)
{
tree param_decl_list;
tree param_decl;
tree next_param;
if (function_nesting_depth++ != 0)
push_function_context ();
announce_function (subprog_decl);
/* Make this field nonzero so further routines know that this is not
tentative. error_mark_node is replaced below (in poplevel) with the
adequate BLOCK. */
DECL_INITIAL (subprog_decl) = error_mark_node;
/* This function exists in static storage. This does not mean `static' in
the C sense! */
TREE_STATIC (subprog_decl) = 1;
/* Enter a new binding level. */
current_function_decl = subprog_decl;
pushlevel (0);
/* Push all the PARM_DECL nodes onto the current scope (i.e. the scope of the
subprogram body) so that they can be recognized as local variables in the
subprogram.
The list of PARM_DECL nodes is stored in the right order in
DECL_ARGUMENTS. Since ..._DECL nodes get stored in the reverse order in
which they are transmitted to `pushdecl' we need to reverse the list of
PARM_DECLs if we want it to be stored in the right order. The reason why
we want to make sure the PARM_DECLs are stored in the correct order is
that this list will be retrieved in a few lines with a call to `getdecl'
to store it back into the DECL_ARGUMENTS field. */
param_decl_list = nreverse (DECL_ARGUMENTS (subprog_decl));
for (param_decl = param_decl_list; param_decl; param_decl = next_param)
{
next_param = TREE_CHAIN (param_decl);
TREE_CHAIN (param_decl) = NULL;
pushdecl (param_decl);
}
/* Store back the PARM_DECL nodes. They appear in the right order. */
DECL_ARGUMENTS (subprog_decl) = getdecls ();
init_function_start (subprog_decl);
expand_function_start (subprog_decl, 0);
/* If this function is `main', emit a call to `__main'
to run global initializers, etc. */
if (DECL_ASSEMBLER_NAME (subprog_decl) != 0
&& MAIN_NAME_P (DECL_ASSEMBLER_NAME (subprog_decl))
&& DECL_CONTEXT (subprog_decl) == NULL_TREE)
expand_main_function ();
}
/* Finish the definition of the current subprogram and compile it all the way
to assembler language output. */
void
end_subprog_body (void)
{
tree decl;
tree cico_list;
poplevel (1, 0, 1);
BLOCK_SUPERCONTEXT (DECL_INITIAL (current_function_decl))
= current_function_decl;
/* Mark the RESULT_DECL as being in this subprogram. */
DECL_CONTEXT (DECL_RESULT (current_function_decl)) = current_function_decl;
expand_function_end ();
/* If this is a nested function, push a new GC context. That will keep
local variables on the stack from being collected while we're doing
the compilation of this function. */
if (function_nesting_depth > 1)
ggc_push_context ();
rest_of_compilation (current_function_decl);
if (function_nesting_depth > 1)
ggc_pop_context ();
/* Throw away any VAR_DECLs we made for OUT parameters; they must
not be seen when we call this function and will be in
unallocated memory anyway. */
for (cico_list = TYPE_CI_CO_LIST (TREE_TYPE (current_function_decl));
cico_list != 0; cico_list = TREE_CHAIN (cico_list))
TREE_VALUE (cico_list) = 0;
if (DECL_SAVED_INSNS (current_function_decl) == 0)
{
/* Throw away DECL_RTL in any PARM_DECLs unless this function
was saved for inline, in which case the DECL_RTLs are in
preserved memory. */
for (decl = DECL_ARGUMENTS (current_function_decl);
decl != 0; decl = TREE_CHAIN (decl))
{
SET_DECL_RTL (decl, 0);
DECL_INCOMING_RTL (decl) = 0;
}
/* Similarly, discard DECL_RTL of the return value. */
SET_DECL_RTL (DECL_RESULT (current_function_decl), 0);
/* But DECL_INITIAL must remain nonzero so we know this
was an actual function definition unless toplev.c decided not
to inline it. */
if (DECL_INITIAL (current_function_decl) != 0)
DECL_INITIAL (current_function_decl) = error_mark_node;
DECL_ARGUMENTS (current_function_decl) = 0;
}
/* If we are not at the bottom of the function nesting stack, pop up to
the containing function. Otherwise show we aren't in any function. */
if (--function_nesting_depth != 0)
pop_function_context ();
else
current_function_decl = 0;
}
/* Return a definition for a builtin function named NAME and whose data type
is TYPE. TYPE should be a function type with argument types.
FUNCTION_CODE tells later passes how to compile calls to this function.
See tree.h for its possible values.
If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
the name to be called if we can't opencode the function. If
ATTRS is nonzero, use that for the function attribute list. */
tree
builtin_function (const char *name,
tree type,
int function_code,
enum built_in_class class,
const char *library_name,
tree attrs)
{
tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type);
DECL_EXTERNAL (decl) = 1;
TREE_PUBLIC (decl) = 1;
if (library_name)
SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name));
pushdecl (decl);
DECL_BUILT_IN_CLASS (decl) = class;
DECL_FUNCTION_CODE (decl) = function_code;
if (attrs)
decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
return decl;
}
/* Return an integer type with the number of bits of precision given by
PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
it is a signed type. */
tree
gnat_type_for_size (unsigned precision, int unsignedp)
{
tree t;
char type_name[20];
if (precision <= 2 * MAX_BITS_PER_WORD
&& signed_and_unsigned_types[precision][unsignedp] != 0)
return signed_and_unsigned_types[precision][unsignedp];
if (unsignedp)
t = make_unsigned_type (precision);
else
t = make_signed_type (precision);
if (precision <= 2 * MAX_BITS_PER_WORD)
signed_and_unsigned_types[precision][unsignedp] = t;
if (TYPE_NAME (t) == 0)
{
sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision);
TYPE_NAME (t) = get_identifier (type_name);
}
return t;
}
/* Likewise for floating-point types. */
static tree
float_type_for_precision (int precision, enum machine_mode mode)
{
tree t;
char type_name[20];
if (float_types[(int) mode] != 0)
return float_types[(int) mode];
float_types[(int) mode] = t = make_node (REAL_TYPE);
TYPE_PRECISION (t) = precision;
layout_type (t);
if (TYPE_MODE (t) != mode)
gigi_abort (414);
if (TYPE_NAME (t) == 0)
{
sprintf (type_name, "FLOAT_%d", precision);
TYPE_NAME (t) = get_identifier (type_name);
}
return t;
}
/* Return a data type that has machine mode MODE. UNSIGNEDP selects
an unsigned type; otherwise a signed type is returned. */
tree
gnat_type_for_mode (enum machine_mode mode, int unsignedp)
{
if (GET_MODE_CLASS (mode) == MODE_FLOAT)
return float_type_for_precision (GET_MODE_PRECISION (mode), mode);
else
return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
}
/* Return the unsigned version of a TYPE_NODE, a scalar type. */
tree
gnat_unsigned_type (tree type_node)
{
tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1);
if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
{
type = copy_node (type);
TREE_TYPE (type) = type_node;
}
else if (TREE_TYPE (type_node) != 0
&& TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
&& TYPE_MODULAR_P (TREE_TYPE (type_node)))
{
type = copy_node (type);
TREE_TYPE (type) = TREE_TYPE (type_node);
}
return type;
}
/* Return the signed version of a TYPE_NODE, a scalar type. */
tree
gnat_signed_type (tree type_node)
{
tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0);
if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
{
type = copy_node (type);
TREE_TYPE (type) = type_node;
}
else if (TREE_TYPE (type_node) != 0
&& TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
&& TYPE_MODULAR_P (TREE_TYPE (type_node)))
{
type = copy_node (type);
TREE_TYPE (type) = TREE_TYPE (type_node);
}
return type;
}
/* Return a type the same as TYPE except unsigned or signed according to
UNSIGNEDP. */
tree
gnat_signed_or_unsigned_type (int unsignedp, tree type)
{
if (! INTEGRAL_TYPE_P (type) || TREE_UNSIGNED (type) == unsignedp)
return type;
else
return gnat_type_for_size (TYPE_PRECISION (type), unsignedp);
}
/* EXP is an expression for the size of an object. If this size contains
discriminant references, replace them with the maximum (if MAX_P) or
minimum (if ! MAX_P) possible value of the discriminant. */
tree
max_size (tree exp, int max_p)
{
enum tree_code code = TREE_CODE (exp);
tree type = TREE_TYPE (exp);
switch (TREE_CODE_CLASS (code))
{
case 'd':
case 'c':
return exp;
case 'x':
if (code == TREE_LIST)
return tree_cons (TREE_PURPOSE (exp),
max_size (TREE_VALUE (exp), max_p),
TREE_CHAIN (exp) != 0
? max_size (TREE_CHAIN (exp), max_p) : 0);
break;
case 'r':
/* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
modify. Otherwise, we treat it like a variable. */
if (! CONTAINS_PLACEHOLDER_P (exp))
return exp;
type = TREE_TYPE (TREE_OPERAND (exp, 1));
return
max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), 1);
case '<':
return max_p ? size_one_node : size_zero_node;
case '1':
case '2':
case 'e':
switch (TREE_CODE_LENGTH (code))
{
case 1:
if (code == NON_LVALUE_EXPR)
return max_size (TREE_OPERAND (exp, 0), max_p);
else
return
fold (build1 (code, type,
max_size (TREE_OPERAND (exp, 0),
code == NEGATE_EXPR ? ! max_p : max_p)));
case 2:
if (code == RTL_EXPR)
gigi_abort (407);
else if (code == COMPOUND_EXPR)
return max_size (TREE_OPERAND (exp, 1), max_p);
else if (code == WITH_RECORD_EXPR)
return exp;
{
tree lhs = max_size (TREE_OPERAND (exp, 0), max_p);
tree rhs = max_size (TREE_OPERAND (exp, 1),
code == MINUS_EXPR ? ! max_p : max_p);
/* Special-case wanting the maximum value of a MIN_EXPR.
In that case, if one side overflows, return the other.
sizetype is signed, but we know sizes are non-negative.
Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
overflowing or the maximum possible value and the RHS
a variable. */
if (max_p && code == MIN_EXPR && TREE_OVERFLOW (rhs))
return lhs;
else if (max_p && code == MIN_EXPR && TREE_OVERFLOW (lhs))
return rhs;
else if ((code == MINUS_EXPR || code == PLUS_EXPR)
&& ((TREE_CONSTANT (lhs) && TREE_OVERFLOW (lhs))
|| operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0))
&& ! TREE_CONSTANT (rhs))
return lhs;
else
return fold (build (code, type, lhs, rhs));
}
case 3:
if (code == SAVE_EXPR)
return exp;
else if (code == COND_EXPR)
return fold (build (MAX_EXPR, type,
max_size (TREE_OPERAND (exp, 1), max_p),
max_size (TREE_OPERAND (exp, 2), max_p)));
else if (code == CALL_EXPR && TREE_OPERAND (exp, 1) != 0)
return build (CALL_EXPR, type, TREE_OPERAND (exp, 0),
max_size (TREE_OPERAND (exp, 1), max_p));
}
}
gigi_abort (408);
}
/* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
Return a constructor for the template. */
tree
build_template (tree template_type, tree array_type, tree expr)
{
tree template_elts = NULL_TREE;
tree bound_list = NULL_TREE;
tree field;
if (TREE_CODE (array_type) == RECORD_TYPE
&& (TYPE_IS_PADDING_P (array_type)
|| TYPE_LEFT_JUSTIFIED_MODULAR_P (array_type)))
array_type = TREE_TYPE (TYPE_FIELDS (array_type));
if (TREE_CODE (array_type) == ARRAY_TYPE
|| (TREE_CODE (array_type) == INTEGER_TYPE
&& TYPE_HAS_ACTUAL_BOUNDS_P (array_type)))
bound_list = TYPE_ACTUAL_BOUNDS (array_type);
/* First make the list for a CONSTRUCTOR for the template. Go down the
field list of the template instead of the type chain because this
array might be an Ada array of arrays and we can't tell where the
nested arrays stop being the underlying object. */
for (field = TYPE_FIELDS (template_type); field;
(bound_list != 0
? (bound_list = TREE_CHAIN (bound_list))
: (array_type = TREE_TYPE (array_type))),
field = TREE_CHAIN (TREE_CHAIN (field)))
{
tree bounds, min, max;
/* If we have a bound list, get the bounds from there. Likewise
for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
This will give us a maximum range. */
if (bound_list != 0)
bounds = TREE_VALUE (bound_list);
else if (TREE_CODE (array_type) == ARRAY_TYPE)
bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type));
else if (expr != 0 && TREE_CODE (expr) == PARM_DECL
&& DECL_BY_COMPONENT_PTR_P (expr))
bounds = TREE_TYPE (field);
else
gigi_abort (411);
min = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MIN_VALUE (bounds));
max = convert (TREE_TYPE (field), TYPE_MAX_VALUE (bounds));
/* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
surround them with a WITH_RECORD_EXPR giving EXPR as the
OBJECT. */
if (CONTAINS_PLACEHOLDER_P (min))
min = build (WITH_RECORD_EXPR, TREE_TYPE (min), min, expr);
if (CONTAINS_PLACEHOLDER_P (max))
max = build (WITH_RECORD_EXPR, TREE_TYPE (max), max, expr);
template_elts = tree_cons (TREE_CHAIN (field), max,
tree_cons (field, min, template_elts));
}
return gnat_build_constructor (template_type, nreverse (template_elts));
}
/* Build a VMS descriptor from a Mechanism_Type, which must specify
a descriptor type, and the GCC type of an object. Each FIELD_DECL
in the type contains in its DECL_INITIAL the expression to use when
a constructor is made for the type. GNAT_ENTITY is a gnat node used
to print out an error message if the mechanism cannot be applied to
an object of that type and also for the name. */
tree
build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
{
tree record_type = make_node (RECORD_TYPE);
tree field_list = 0;
int class;
int dtype = 0;
tree inner_type;
int ndim;
int i;
tree *idx_arr;
tree tem;
/* If TYPE is an unconstrained array, use the underlying array type. */
if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
/* If this is an array, compute the number of dimensions in the array,
get the index types, and point to the inner type. */
if (TREE_CODE (type) != ARRAY_TYPE)
ndim = 0;
else
for (ndim = 1, inner_type = type;
TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
&& TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
ndim++, inner_type = TREE_TYPE (inner_type))
;
idx_arr = (tree *) alloca (ndim * sizeof (tree));
if (mech != By_Descriptor_NCA
&& TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
for (i = ndim - 1, inner_type = type;
i >= 0;
i--, inner_type = TREE_TYPE (inner_type))
idx_arr[i] = TYPE_DOMAIN (inner_type);
else
for (i = 0, inner_type = type;
i < ndim;
i++, inner_type = TREE_TYPE (inner_type))
idx_arr[i] = TYPE_DOMAIN (inner_type);
/* Now get the DTYPE value. */
switch (TREE_CODE (type))
{
case INTEGER_TYPE:
case ENUMERAL_TYPE:
if (TYPE_VAX_FLOATING_POINT_P (type))
switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
{
case 6:
dtype = 10;
break;
case 9:
dtype = 11;
break;
case 15:
dtype = 27;
break;
}
else
switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
{
case 8:
dtype = TREE_UNSIGNED (type) ? 2 : 6;
break;
case 16:
dtype = TREE_UNSIGNED (type) ? 3 : 7;
break;
case 32:
dtype = TREE_UNSIGNED (type) ? 4 : 8;
break;
case 64:
dtype = TREE_UNSIGNED (type) ? 5 : 9;
break;
case 128:
dtype = TREE_UNSIGNED (type) ? 25 : 26;
break;
}
break;
case REAL_TYPE:
dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
break;
case COMPLEX_TYPE:
if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
&& TYPE_VAX_FLOATING_POINT_P (type))
switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
{
case 6:
dtype = 12;
break;
case 9:
dtype = 13;
break;
case 15:
dtype = 29;
}
else
dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
break;
case ARRAY_TYPE:
dtype = 14;
break;
default:
break;
}
/* Get the CLASS value. */
switch (mech)
{
case By_Descriptor_A:
class = 4;
break;
case By_Descriptor_NCA:
class = 10;
break;
case By_Descriptor_SB:
class = 15;
break;
default:
class = 1;
}
/* Make the type for a descriptor for VMS. The first four fields
are the same for all types. */
field_list
= chainon (field_list,
make_descriptor_field
("LENGTH", gnat_type_for_size (16, 1), record_type,
size_in_bytes (mech == By_Descriptor_A ? inner_type : type)));
field_list = chainon (field_list,
make_descriptor_field ("DTYPE",
gnat_type_for_size (8, 1),
record_type, size_int (dtype)));
field_list = chainon (field_list,
make_descriptor_field ("CLASS",
gnat_type_for_size (8, 1),
record_type, size_int (class)));
field_list
= chainon (field_list,
make_descriptor_field ("POINTER",
build_pointer_type (type),
record_type,
build1 (ADDR_EXPR,
build_pointer_type (type),
build (PLACEHOLDER_EXPR,
type))));
switch (mech)
{
case By_Descriptor:
case By_Descriptor_S:
break;
case By_Descriptor_SB:
field_list
= chainon (field_list,
make_descriptor_field
("SB_L1", gnat_type_for_size (32, 1), record_type,
TREE_CODE (type) == ARRAY_TYPE
? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
field_list
= chainon (field_list,
make_descriptor_field
("SB_L2", gnat_type_for_size (32, 1), record_type,
TREE_CODE (type) == ARRAY_TYPE
? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
break;
case By_Descriptor_A:
case By_Descriptor_NCA:
field_list = chainon (field_list,
make_descriptor_field ("SCALE",
gnat_type_for_size (8, 1),
record_type,
size_zero_node));
field_list = chainon (field_list,
make_descriptor_field ("DIGITS",
gnat_type_for_size (8, 1),
record_type,
size_zero_node));
field_list
= chainon (field_list,
make_descriptor_field
("AFLAGS", gnat_type_for_size (8, 1), record_type,
size_int (mech == By_Descriptor_NCA
? 0
/* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
: (TREE_CODE (type) == ARRAY_TYPE
&& TYPE_CONVENTION_FORTRAN_P (type)
? 224 : 192))));
field_list = chainon (field_list,
make_descriptor_field ("DIMCT",
gnat_type_for_size (8, 1),
record_type,
size_int (ndim)));
field_list = chainon (field_list,
make_descriptor_field ("ARSIZE",
gnat_type_for_size (32, 1),
record_type,
size_in_bytes (type)));
/* Now build a pointer to the 0,0,0... element. */
tem = build (PLACEHOLDER_EXPR, type);
for (i = 0, inner_type = type; i < ndim;
i++, inner_type = TREE_TYPE (inner_type))
tem = build (ARRAY_REF, TREE_TYPE (inner_type), tem,
convert (TYPE_DOMAIN (inner_type), size_zero_node));
field_list
= chainon (field_list,
make_descriptor_field
("A0", build_pointer_type (inner_type), record_type,
build1 (ADDR_EXPR, build_pointer_type (inner_type), tem)));
/* Next come the addressing coefficients. */
tem = size_int (1);
for (i = 0; i < ndim; i++)
{
char fname[3];
tree idx_length
= size_binop (MULT_EXPR, tem,
size_binop (PLUS_EXPR,
size_binop (MINUS_EXPR,
TYPE_MAX_VALUE (idx_arr[i]),
TYPE_MIN_VALUE (idx_arr[i])),
size_int (1)));
fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M');
fname[1] = '0' + i, fname[2] = 0;
field_list
= chainon (field_list,
make_descriptor_field (fname,
gnat_type_for_size (32, 1),
record_type, idx_length));
if (mech == By_Descriptor_NCA)
tem = idx_length;
}
/* Finally here are the bounds. */
for (i = 0; i < ndim; i++)
{
char fname[3];
fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
field_list
= chainon (field_list,
make_descriptor_field
(fname, gnat_type_for_size (32, 1), record_type,
TYPE_MIN_VALUE (idx_arr[i])));
fname[0] = 'U';
field_list
= chainon (field_list,
make_descriptor_field
(fname, gnat_type_for_size (32, 1), record_type,
TYPE_MAX_VALUE (idx_arr[i])));
}
break;
default:
post_error ("unsupported descriptor type for &", gnat_entity);
}
finish_record_type (record_type, field_list, 0, 1);
pushdecl (build_decl (TYPE_DECL, create_concat_name (gnat_entity, "DESC"),
record_type));
return record_type;
}
/* Utility routine for above code to make a field. */
static tree
make_descriptor_field (const char *name, tree type,
tree rec_type, tree initial)
{
tree field
= create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0);
DECL_INITIAL (field) = initial;
return field;
}
/* Build a type to be used to represent an aliased object whose nominal
type is an unconstrained array. This consists of a RECORD_TYPE containing
a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this
is used to represent an arbitrary unconstrained object. Use NAME
as the name of the record. */
tree
build_unc_object_type (tree template_type, tree object_type, tree name)
{
tree type = make_node (RECORD_TYPE);
tree template_field = create_field_decl (get_identifier ("BOUNDS"),
template_type, type, 0, 0, 0, 1);
tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type,
type, 0, 0, 0, 1);
TYPE_NAME (type) = name;
TYPE_CONTAINS_TEMPLATE_P (type) = 1;
finish_record_type (type,
chainon (chainon (NULL_TREE, template_field),
array_field),
0, 0);
return type;
}
/* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. In
the normal case this is just two adjustments, but we have more to do
if NEW is an UNCONSTRAINED_ARRAY_TYPE. */
void
update_pointer_to (tree old_type, tree new_type)
{
tree ptr = TYPE_POINTER_TO (old_type);
tree ref = TYPE_REFERENCE_TO (old_type);
tree type;
/* If this is the main variant, process all the other variants first. */
if (TYPE_MAIN_VARIANT (old_type) == old_type)
for (type = TYPE_NEXT_VARIANT (old_type); type != 0;
type = TYPE_NEXT_VARIANT (type))
update_pointer_to (type, new_type);
/* If no pointer or reference, we are done. */
if (ptr == 0 && ref == 0)
return;
/* Merge the old type qualifiers in the new type.
Each old variant has qualifiers for specific reasons, and the new
designated type as well. Each set of qualifiers represents useful
information grabbed at some point, and merging the two simply unifies
these inputs into the final type description.
Consider for instance a volatile type frozen after an access to constant
type designating it. After the designated type freeze, we get here with a
volatile new_type and a dummy old_type with a readonly variant, created
when the access type was processed. We shall make a volatile and readonly
designated type, because that's what it really is.
We might also get here for a non-dummy old_type variant with different
qualifiers than the new_type ones, for instance in some cases of pointers
to private record type elaboration (see the comments around the call to
this routine from gnat_to_gnu_entity/E_Access_Type). We have to merge the
qualifiers in thoses cases too, to avoid accidentally discarding the
initial set, and will often end up with old_type == new_type then. */
new_type = build_qualified_type (new_type,
TYPE_QUALS (old_type)
| TYPE_QUALS (new_type));
/* If the new type and the old one are identical, there is nothing to
update. */
if (old_type == new_type)
return;
/* Otherwise, first handle the simple case. */
if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE)
{
if (ptr != 0)
TREE_TYPE (ptr) = new_type;
TYPE_POINTER_TO (new_type) = ptr;
if (ref != 0)
TREE_TYPE (ref) = new_type;
TYPE_REFERENCE_TO (new_type) = ref;
if (ptr != 0 && TYPE_NAME (ptr) != 0
&& TREE_CODE (TYPE_NAME (ptr)) == TYPE_DECL
&& TREE_CODE (new_type) != ENUMERAL_TYPE)
rest_of_decl_compilation (TYPE_NAME (ptr), NULL,
global_bindings_p (), 0);
if (ref != 0 && TYPE_NAME (ref) != 0
&& TREE_CODE (TYPE_NAME (ref)) == TYPE_DECL
&& TREE_CODE (new_type) != ENUMERAL_TYPE)
rest_of_decl_compilation (TYPE_NAME (ref), NULL,
global_bindings_p (), 0);
}
/* Now deal with the unconstrained array case. In this case the "pointer"
is actually a RECORD_TYPE where the types of both fields are
pointers to void. In that case, copy the field list from the
old type to the new one and update the fields' context. */
else if (TREE_CODE (ptr) != RECORD_TYPE || ! TYPE_IS_FAT_POINTER_P (ptr))
gigi_abort (412);
else
{
tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type);
tree ptr_temp_type;
tree new_ref;
tree var;
TYPE_FIELDS (ptr) = TYPE_FIELDS (TYPE_POINTER_TO (new_type));
DECL_CONTEXT (TYPE_FIELDS (ptr)) = ptr;
DECL_CONTEXT (TREE_CHAIN (TYPE_FIELDS (ptr))) = ptr;
/* Rework the PLACEHOLDER_EXPR inside the reference to the
template bounds.
??? This is now the only use of gnat_substitute_in_type, which
is now a very "heavy" routine to do this, so it should be replaced
at some point. */
ptr_temp_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (ptr)));
new_ref = build (COMPONENT_REF, ptr_temp_type,
build (PLACEHOLDER_EXPR, ptr),
TREE_CHAIN (TYPE_FIELDS (ptr)));
update_pointer_to
(TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
gnat_substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
TREE_CHAIN (TYPE_FIELDS (ptr)), new_ref));
for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var))
SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type);
TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type)
= TREE_TYPE (new_type) = ptr;
/* Now handle updating the allocation record, what the thin pointer
points to. Update all pointers from the old record into the new
one, update the types of the fields, and recompute the size. */
update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec);
TREE_TYPE (TYPE_FIELDS (new_obj_rec)) = TREE_TYPE (ptr_temp_type);
TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
= TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr)));
DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
= TYPE_SIZE (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
= TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
TYPE_SIZE (new_obj_rec)
= size_binop (PLUS_EXPR,
DECL_SIZE (TYPE_FIELDS (new_obj_rec)),
DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
TYPE_SIZE_UNIT (new_obj_rec)
= size_binop (PLUS_EXPR,
DECL_SIZE_UNIT (TYPE_FIELDS (new_obj_rec)),
DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
rest_of_type_compilation (ptr, global_bindings_p ());
}
}
/* Convert a pointer to a constrained array into a pointer to a fat
pointer. This involves making or finding a template. */
static tree
convert_to_fat_pointer (tree type, tree expr)
{
tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))));
tree template, template_addr;
tree etype = TREE_TYPE (expr);
/* If EXPR is a constant of zero, we make a fat pointer that has a null
pointer to the template and array. */
if (integer_zerop (expr))
return
gnat_build_constructor
(type,
tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
convert (build_pointer_type (template_type),
expr),
NULL_TREE)));
/* If EXPR is a thin pointer, make the template and data from the record. */
else if (TYPE_THIN_POINTER_P (etype))
{
tree fields = TYPE_FIELDS (TREE_TYPE (etype));
expr = save_expr (expr);
if (TREE_CODE (expr) == ADDR_EXPR)
expr = TREE_OPERAND (expr, 0);
else
expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr);
template = build_component_ref (expr, NULL_TREE, fields, 0);
expr = build_unary_op (ADDR_EXPR, NULL_TREE,
build_component_ref (expr, NULL_TREE,
TREE_CHAIN (fields), 0));
}
else
/* Otherwise, build the constructor for the template. */
template = build_template (template_type, TREE_TYPE (etype), expr);
template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
/* The result is a CONSTRUCTOR for the fat pointer.
If expr is an argument of a foreign convention subprogram, the type it
points to is directly the component type. In this case, the expression
type may not match the corresponding FIELD_DECL type at this point, so we
call "convert" here to fix that up if necessary. This type consistency is
required, for instance because it ensures that possible later folding of
component_refs against this constructor always yields something of the
same type as the initial reference.
Note that the call to "build_template" above is still fine, because it
will only refer to the provided template_type in this case. */
return
gnat_build_constructor
(type, tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
template_addr, NULL_TREE)));
}
/* Convert to a thin pointer type, TYPE. The only thing we know how to convert
is something that is a fat pointer, so convert to it first if it EXPR
is not already a fat pointer. */
static tree
convert_to_thin_pointer (tree type, tree expr)
{
if (! TYPE_FAT_POINTER_P (TREE_TYPE (expr)))
expr
= convert_to_fat_pointer
(TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr);
/* We get the pointer to the data and use a NOP_EXPR to make it the
proper GCC type. */
expr
= build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)), 0);
expr = build1 (NOP_EXPR, type, expr);
return expr;
}
/* Create an expression whose value is that of EXPR,
converted to type TYPE. The TREE_TYPE of the value
is always TYPE. This function implements all reasonable
conversions; callers should filter out those that are
not permitted by the language being compiled. */
tree
convert (tree type, tree expr)
{
enum tree_code code = TREE_CODE (type);
tree etype = TREE_TYPE (expr);
enum tree_code ecode = TREE_CODE (etype);
tree tem;
/* If EXPR is already the right type, we are done. */
if (type == etype)
return expr;
/* If we're converting between two aggregate types that have the same main
variant, just make a NOP_EXPR. */
else if (AGGREGATE_TYPE_P (type)
&& TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
return build1 (NOP_EXPR, type, expr);
/* If EXPR is a WITH_RECORD_EXPR, do the conversion inside and then make a
new one. */
else if (TREE_CODE (expr) == WITH_RECORD_EXPR)
return build (WITH_RECORD_EXPR, type,
convert (type, TREE_OPERAND (expr, 0)),
TREE_OPERAND (expr, 1));
/* If the input type has padding, remove it by doing a component reference
to the field. If the output type has padding, make a constructor
to build the record. If both input and output have padding and are
of variable size, do this as an unchecked conversion. */
else if (ecode == RECORD_TYPE && code == RECORD_TYPE
&& TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype)
&& (! TREE_CONSTANT (TYPE_SIZE (type))
|| ! TREE_CONSTANT (TYPE_SIZE (etype))))
;
else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype))
{
/* If we have just converted to this padded type, just get
the inner expression. */
if (TREE_CODE (expr) == CONSTRUCTOR
&& CONSTRUCTOR_ELTS (expr) != 0
&& TREE_PURPOSE (CONSTRUCTOR_ELTS (expr)) == TYPE_FIELDS (etype))
return TREE_VALUE (CONSTRUCTOR_ELTS (expr));
else
return convert (type, build_component_ref (expr, NULL_TREE,
TYPE_FIELDS (etype), 0));
}
else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type))
{
/* If we previously converted from another type and our type is
of variable size, remove the conversion to avoid the need for
variable-size temporaries. */
if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
&& ! TREE_CONSTANT (TYPE_SIZE (type)))
expr = TREE_OPERAND (expr, 0);
/* If we are just removing the padding from expr, convert the original
object if we have variable size. That will avoid the need
for some variable-size temporaries. */
if (TREE_CODE (expr) == COMPONENT_REF
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE
&& TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
&& ! TREE_CONSTANT (TYPE_SIZE (type)))
return convert (type, TREE_OPERAND (expr, 0));
/* If the result type is a padded type with a self-referentially-sized
field and the expression type is a record, do this as an
unchecked converstion. */
else if (TREE_CODE (etype) == RECORD_TYPE
&& CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))))
return unchecked_convert (type, expr, 0);
else
return
gnat_build_constructor (type,
tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE
(TYPE_FIELDS (type)),
expr),
NULL_TREE));
}
/* If the input is a biased type, adjust first. */
if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
return convert (type, fold (build (PLUS_EXPR, TREE_TYPE (etype),
fold (build1 (GNAT_NOP_EXPR,
TREE_TYPE (etype), expr)),
TYPE_MIN_VALUE (etype))));
/* If the input is a left-justified modular type, we need to extract
the actual object before converting it to any other type with the
exception of an unconstrained array. */
if (ecode == RECORD_TYPE && TYPE_LEFT_JUSTIFIED_MODULAR_P (etype)
&& code != UNCONSTRAINED_ARRAY_TYPE)
return convert (type, build_component_ref (expr, NULL_TREE,
TYPE_FIELDS (etype), 0));
/* If converting to a type that contains a template, convert to the data
type and then build the template. */
if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type))
{
tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)));
/* If the source already has a template, get a reference to the
associated array only, as we are going to rebuild a template
for the target type anyway. */
expr = maybe_unconstrained_array (expr);
return
gnat_build_constructor
(type,
tree_cons (TYPE_FIELDS (type),
build_template (TREE_TYPE (TYPE_FIELDS (type)),
obj_type, NULL_TREE),
tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
convert (obj_type, expr), NULL_TREE)));
}
/* There are some special cases of expressions that we process
specially. */
switch (TREE_CODE (expr))
{
case ERROR_MARK:
return expr;
case TRANSFORM_EXPR:
case NULL_EXPR:
/* Just set its type here. For TRANSFORM_EXPR, we will do the actual
conversion in gnat_expand_expr. NULL_EXPR does not represent
and actual value, so no conversion is needed. */
expr = copy_node (expr);
TREE_TYPE (expr) = type;
return expr;
case STRING_CST:
case CONSTRUCTOR:
/* If we are converting a STRING_CST to another constrained array type,
just make a new one in the proper type. Likewise for a
CONSTRUCTOR. */
if (code == ecode && AGGREGATE_TYPE_P (etype)
&& ! (TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST
&& TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
{
expr = copy_node (expr);
TREE_TYPE (expr) = type;
return expr;
}
break;
case COMPONENT_REF:
/* If we are converting between two aggregate types of the same
kind, size, mode, and alignment, just make a new COMPONENT_REF.
This avoid unneeded conversions which makes reference computations
more complex. */
if (code == ecode && TYPE_MODE (type) == TYPE_MODE (etype)
&& AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)
&& TYPE_ALIGN (type) == TYPE_ALIGN (etype)
&& operand_equal_p (TYPE_SIZE (type), TYPE_SIZE (etype), 0))
return build (COMPONENT_REF, type, TREE_OPERAND (expr, 0),
TREE_OPERAND (expr, 1));
break;
case UNCONSTRAINED_ARRAY_REF:
/* Convert this to the type of the inner array by getting the address of
the array from the template. */
expr = build_unary_op (INDIRECT_REF, NULL_TREE,
build_component_ref (TREE_OPERAND (expr, 0),
get_identifier ("P_ARRAY"),
NULL_TREE, 0));
etype = TREE_TYPE (expr);
ecode = TREE_CODE (etype);
break;
case VIEW_CONVERT_EXPR:
if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)
&& ! TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype))
return convert (type, TREE_OPERAND (expr, 0));
break;
case INDIRECT_REF:
/* If both types are record types, just convert the pointer and
make a new INDIRECT_REF.
??? Disable this for now since it causes problems with the
code in build_binary_op for MODIFY_EXPR which wants to
strip off conversions. But that code really is a mess and
we need to do this a much better way some time. */
if (0
&& (TREE_CODE (type) == RECORD_TYPE
|| TREE_CODE (type) == UNION_TYPE)
&& (TREE_CODE (etype) == RECORD_TYPE
|| TREE_CODE (etype) == UNION_TYPE)
&& ! TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype))
return build_unary_op (INDIRECT_REF, NULL_TREE,
convert (build_pointer_type (type),
TREE_OPERAND (expr, 0)));
break;
default:
break;
}
/* Check for converting to a pointer to an unconstrained array. */
if (TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype))
return convert_to_fat_pointer (type, expr);
if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)
|| (code == INTEGER_CST && ecode == INTEGER_CST
&& (type == TREE_TYPE (etype) || etype == TREE_TYPE (type))))
return fold (build1 (NOP_EXPR, type, expr));
switch (code)
{
case VOID_TYPE:
return build1 (CONVERT_EXPR, type, expr);
case INTEGER_TYPE:
if (TYPE_HAS_ACTUAL_BOUNDS_P (type)
&& (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
|| (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
return unchecked_convert (type, expr, 0);
else if (TYPE_BIASED_REPRESENTATION_P (type))
return fold (build1 (CONVERT_EXPR, type,
fold (build (MINUS_EXPR, TREE_TYPE (type),
convert (TREE_TYPE (type), expr),
TYPE_MIN_VALUE (type)))));
/* ... fall through ... */
case ENUMERAL_TYPE:
return fold (convert_to_integer (type, expr));
case POINTER_TYPE:
case REFERENCE_TYPE:
/* If converting between two pointers to records denoting
both a template and type, adjust if needed to account
for any differing offsets, since one might be negative. */
if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type))
{
tree bit_diff
= size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))),
bit_position (TYPE_FIELDS (TREE_TYPE (type))));
tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff,
sbitsize_int (BITS_PER_UNIT));
expr = build1 (NOP_EXPR, type, expr);
TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0));
if (integer_zerop (byte_diff))
return expr;
return build_binary_op (PLUS_EXPR, type, expr,
fold (convert_to_pointer (type, byte_diff)));
}
/* If converting to a thin pointer, handle specially. */
if (TYPE_THIN_POINTER_P (type)
&& TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)) != 0)
return convert_to_thin_pointer (type, expr);
/* If converting fat pointer to normal pointer, get the pointer to the
array and then convert it. */
else if (TYPE_FAT_POINTER_P (etype))
expr = build_component_ref (expr, get_identifier ("P_ARRAY"),
NULL_TREE, 0);
return fold (convert_to_pointer (type, expr));
case REAL_TYPE:
return fold (convert_to_real (type, expr));
case RECORD_TYPE:
if (TYPE_LEFT_JUSTIFIED_MODULAR_P (type) && ! AGGREGATE_TYPE_P (etype))
return
gnat_build_constructor
(type, tree_cons (TYPE_FIELDS (type),
convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
NULL_TREE));
/* ... fall through ... */
case ARRAY_TYPE:
/* In these cases, assume the front-end has validated the conversion.
If the conversion is valid, it will be a bit-wise conversion, so
it can be viewed as an unchecked conversion. */
return unchecked_convert (type, expr, 0);
case UNION_TYPE:
/* Just validate that the type is indeed that of a field
of the type. Then make the simple conversion. */
for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem))
{
if (TREE_TYPE (tem) == etype)
return build1 (CONVERT_EXPR, type, expr);
else if (TREE_CODE (TREE_TYPE (tem)) == RECORD_TYPE
&& (TYPE_LEFT_JUSTIFIED_MODULAR_P (TREE_TYPE (tem))
|| TYPE_IS_PADDING_P (TREE_TYPE (tem)))
&& TREE_TYPE (TYPE_FIELDS (TREE_TYPE (tem))) == etype)
return build1 (CONVERT_EXPR, type,
convert (TREE_TYPE (tem), expr));
}
gigi_abort (413);
case UNCONSTRAINED_ARRAY_TYPE:
/* If EXPR is a constrained array, take its address, convert it to a
fat pointer, and then dereference it. Likewise if EXPR is a
record containing both a template and a constrained array.
Note that a record representing a left justified modular type
always represents a packed constrained array. */
if (ecode == ARRAY_TYPE
|| (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype))
|| (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))
|| (ecode == RECORD_TYPE && TYPE_LEFT_JUSTIFIED_MODULAR_P (etype)))
return
build_unary_op
(INDIRECT_REF, NULL_TREE,
convert_to_fat_pointer (TREE_TYPE (type),
build_unary_op (ADDR_EXPR,
NULL_TREE, expr)));
/* Do something very similar for converting one unconstrained
array to another. */
else if (ecode == UNCONSTRAINED_ARRAY_TYPE)
return
build_unary_op (INDIRECT_REF, NULL_TREE,
convert (TREE_TYPE (type),
build_unary_op (ADDR_EXPR,
NULL_TREE, expr)));
else
gigi_abort (409);
case COMPLEX_TYPE:
return fold (convert_to_complex (type, expr));
default:
gigi_abort (410);
}
}
/* Remove all conversions that are done in EXP. This includes converting
from a padded type or to a left-justified modular type. If TRUE_ADDRESS
is nonzero, always return the address of the containing object even if
the address is not bit-aligned. */
tree
remove_conversions (tree exp, int true_address)
{
switch (TREE_CODE (exp))
{
case CONSTRUCTOR:
if (true_address
&& TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
&& TYPE_LEFT_JUSTIFIED_MODULAR_P (TREE_TYPE (exp)))
return remove_conversions (TREE_VALUE (CONSTRUCTOR_ELTS (exp)), 1);
break;
case COMPONENT_REF:
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE
&& TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
return remove_conversions (TREE_OPERAND (exp, 0), true_address);
break;