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/* Subroutines shared by all languages that are variants of C.
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
2001, 2002 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "tree.h"
#include "real.h"
#include "flags.h"
#include "toplev.h"
#include "output.h"
#include "c-pragma.h"
#include "rtl.h"
#include "ggc.h"
#include "expr.h"
#include "c-common.h"
#include "diagnostic.h"
#include "tm_p.h"
#include "obstack.h"
#include "cpplib.h"
#include "target.h"
#include "langhooks.h"
#include "except.h" /* For USING_SJLJ_EXCEPTIONS. */
#include "tree-inline.h"
#include "c-tree.h"
cpp_reader *parse_in; /* Declared in c-pragma.h. */
/* We let tm.h override the types used here, to handle trivial differences
such as the choice of unsigned int or long unsigned int for size_t.
When machines start needing nontrivial differences in the size type,
it would be best to do something here to figure out automatically
from other information what type to use. */
#ifndef SIZE_TYPE
#define SIZE_TYPE "long unsigned int"
#ifndef WCHAR_TYPE
#define WCHAR_TYPE "int"
/* WCHAR_TYPE gets overridden by -fshort-wchar. */
(flag_short_wchar ? "short unsigned int" : WCHAR_TYPE)
#define PTRDIFF_TYPE "long int"
#ifndef WINT_TYPE
#define WINT_TYPE "unsigned int"
? "int" \
? "long int" \
: "long long int"))
? "unsigned int" \
? "long unsigned int" \
: "long long unsigned int"))
/* The variant of the C language being processed. */
enum c_language_kind c_language;
/* The following symbols are subsumed in the c_global_trees array, and
listed here individually for documentation purposes.
INTEGER_TYPE and REAL_TYPE nodes for the standard data types.
tree short_integer_type_node;
tree long_integer_type_node;
tree long_long_integer_type_node;
tree short_unsigned_type_node;
tree long_unsigned_type_node;
tree long_long_unsigned_type_node;
tree boolean_type_node;
tree boolean_false_node;
tree boolean_true_node;
tree ptrdiff_type_node;
tree unsigned_char_type_node;
tree signed_char_type_node;
tree wchar_type_node;
tree signed_wchar_type_node;
tree unsigned_wchar_type_node;
tree float_type_node;
tree double_type_node;
tree long_double_type_node;
tree complex_integer_type_node;
tree complex_float_type_node;
tree complex_double_type_node;
tree complex_long_double_type_node;
tree intQI_type_node;
tree intHI_type_node;
tree intSI_type_node;
tree intDI_type_node;
tree intTI_type_node;
tree unsigned_intQI_type_node;
tree unsigned_intHI_type_node;
tree unsigned_intSI_type_node;
tree unsigned_intDI_type_node;
tree unsigned_intTI_type_node;
tree widest_integer_literal_type_node;
tree widest_unsigned_literal_type_node;
Nodes for types `void *' and `const void *'.
tree ptr_type_node, const_ptr_type_node;
Nodes for types `char *' and `const char *'.
tree string_type_node, const_string_type_node;
Type `char[SOMENUMBER]'.
Used when an array of char is needed and the size is irrelevant.
tree char_array_type_node;
Type `int[SOMENUMBER]' or something like it.
Used when an array of int needed and the size is irrelevant.
tree int_array_type_node;
Type `wchar_t[SOMENUMBER]' or something like it.
Used when a wide string literal is created.
tree wchar_array_type_node;
Type `int ()' -- used for implicit declaration of functions.
tree default_function_type;
A VOID_TYPE node, packaged in a TREE_LIST.
tree void_list_node;
The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__,
and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__
VAR_DECLS, but C++ does.)
tree function_name_decl_node;
tree pretty_function_name_decl_node;
tree c99_function_name_decl_node;
Stack of nested function name VAR_DECLs.
tree saved_function_name_decls;
tree c_global_trees[CTI_MAX];
/* Switches common to the C front ends. */
/* Nonzero if prepreprocessing only. */
int flag_preprocess_only;
/* Nonzero if an ISO standard was selected. It rejects macros in the
user's namespace. */
int flag_iso;
/* Nonzero whenever Objective-C functionality is being used. */
int flag_objc;
/* Nonzero if -undef was given. It suppresses target built-in macros
and assertions. */
int flag_undef;
/* Nonzero means don't recognize the non-ANSI builtin functions. */
int flag_no_builtin;
/* Nonzero means don't recognize the non-ANSI builtin functions.
-ansi sets this. */
int flag_no_nonansi_builtin;
/* Nonzero means give `double' the same size as `float'. */
int flag_short_double;
/* Nonzero means give `wchar_t' the same size as `short'. */
int flag_short_wchar;
/* Nonzero means allow Microsoft extensions without warnings or errors. */
int flag_ms_extensions;
/* Nonzero means don't recognize the keyword `asm'. */
int flag_no_asm;
/* Nonzero means give string constants the type `const char *', as mandated
by the standard. */
int flag_const_strings;
/* Nonzero means `$' can be in an identifier. */
int dollars_in_ident = DOLLARS_IN_IDENTIFIERS;
/* Nonzero means to treat bitfields as signed unless they say `unsigned'. */
int flag_signed_bitfields = 1;
int explicit_flag_signed_bitfields;
/* Nonzero means warn about pointer casts that can drop a type qualifier
from the pointer target type. */
int warn_cast_qual;
/* Warn about functions which might be candidates for format attributes. */
int warn_missing_format_attribute;
/* Nonzero means warn about sizeof(function) or addition/subtraction
of function pointers. */
int warn_pointer_arith;
/* Nonzero means warn for any global function def
without separate previous prototype decl. */
int warn_missing_prototypes;
/* Warn if adding () is suggested. */
int warn_parentheses;
/* Warn if initializer is not completely bracketed. */
int warn_missing_braces;
/* Warn about comparison of signed and unsigned values.
If -1, neither -Wsign-compare nor -Wno-sign-compare has been specified. */
int warn_sign_compare;
/* Nonzero means warn about usage of long long when `-pedantic'. */
int warn_long_long = 1;
/* Nonzero means warn about deprecated conversion from string constant to
`char *'. */
int warn_write_strings;
/* Nonzero means warn about multiple (redundant) decls for the same single
variable or function. */
int warn_redundant_decls;
/* Warn about testing equality of floating point numbers. */
int warn_float_equal;
/* Warn about a subscript that has type char. */
int warn_char_subscripts;
/* Warn if a type conversion is done that might have confusing results. */
int warn_conversion;
/* Warn about #pragma directives that are not recognized. */
int warn_unknown_pragmas; /* Tri state variable. */
/* Warn about format/argument anomalies in calls to formatted I/O functions
(*printf, *scanf, strftime, strfmon, etc.). */
int warn_format;
/* Warn about Y2K problems with strftime formats. */
int warn_format_y2k;
/* Warn about excess arguments to formats. */
int warn_format_extra_args;
/* Warn about zero-length formats. */
int warn_format_zero_length;
/* Warn about non-literal format arguments. */
int warn_format_nonliteral;
/* Warn about possible security problems with calls to format functions. */
int warn_format_security;
/* C/ObjC language option variables. */
/* Nonzero means message about use of implicit function declarations;
1 means warning; 2 means error. */
int mesg_implicit_function_declaration = -1;
/* Nonzero means allow type mismatches in conditional expressions;
just make their values `void'. */
int flag_cond_mismatch;
/* Nonzero means enable C89 Amendment 1 features. */
int flag_isoc94;
/* Nonzero means use the ISO C99 dialect of C. */
int flag_isoc99;
/* Nonzero means that we have builtin functions, and main is an int */
int flag_hosted = 1;
/* Nonzero means add default format_arg attributes for functions not
in ISO C. */
int flag_noniso_default_format_attributes = 1;
/* Nonzero means warn when casting a function call to a type that does
not match the return type (e.g. (float)sqrt() or (anything*)malloc()
when there is no previous declaration of sqrt or malloc. */
int warn_bad_function_cast;
/* Warn about traditional constructs whose meanings changed in ANSI C. */
int warn_traditional;
/* Nonzero means warn for non-prototype function decls
or non-prototyped defs without previous prototype. */
int warn_strict_prototypes;
/* Nonzero means warn for any global function def
without separate previous decl. */
int warn_missing_declarations;
/* Nonzero means warn about declarations of objects not at
file-scope level and about *all* declarations of functions (whether
or static) not at file-scope level. Note that we exclude
implicit function declarations. To get warnings about those, use
-Wimplicit. */
int warn_nested_externs;
/* Warn if main is suspicious. */
int warn_main;
/* Nonzero means warn about possible violations of sequence point rules. */
int warn_sequence_point;
/* Nonzero means to warn about compile-time division by zero. */
int warn_div_by_zero = 1;
/* Nonzero means warn about use of implicit int. */
int warn_implicit_int;
/* Warn about NULL being passed to argument slots marked as requiring
non-NULL. */
int warn_nonnull;
/* ObjC language option variables. */
/* Open and close the file for outputting class declarations, if
requested (ObjC). */
int flag_gen_declaration;
/* Generate code for GNU or NeXT runtime environment. */
int flag_next_runtime = 1;
int flag_next_runtime = 0;
/* Tells the compiler that this is a special run. Do not perform any
compiling, instead we are to test some platform dependent features
and output a C header file with appropriate definitions. */
int print_struct_values;
/* ???. Undocumented. */
const char *constant_string_class_name;
/* Warn if multiple methods are seen for the same selector, but with
different argument types. Performs the check on the whole selector
table at the end of compilation. */
int warn_selector;
/* Warn if a @selector() is found, and no method with that selector
has been previously declared. The check is done on each
@selector() as soon as it is found - so it warns about forward
declarations. */
int warn_undeclared_selector;
/* Warn if methods required by a protocol are not implemented in the
class adopting it. When turned off, methods inherited to that
class are also considered implemented. */
int warn_protocol = 1;
/* C++ language option variables. */
/* Nonzero means don't recognize any extension keywords. */
int flag_no_gnu_keywords;
/* Nonzero means do emit exported implementations of functions even if
they can be inlined. */
int flag_implement_inlines = 1;
/* Nonzero means do emit exported implementations of templates, instead of
multiple static copies in each file that needs a definition. */
int flag_external_templates;
/* Nonzero means that the decision to emit or not emit the implementation of a
template depends on where the template is instantiated, rather than where
it is defined. */
int flag_alt_external_templates;
/* Nonzero means that implicit instantiations will be emitted if needed. */
int flag_implicit_templates = 1;
/* Nonzero means that implicit instantiations of inline templates will be
emitted if needed, even if instantiations of non-inline templates
aren't. */
int flag_implicit_inline_templates = 1;
/* Nonzero means generate separate instantiation control files and
juggle them at link time. */
int flag_use_repository;
/* Nonzero if we want to issue diagnostics that the standard says are not
required. */
int flag_optional_diags = 1;
/* Nonzero means we should attempt to elide constructors when possible. */
int flag_elide_constructors = 1;
/* Nonzero means that member functions defined in class scope are
inline by default. */
int flag_default_inline = 1;
/* Controls whether compiler generates 'type descriptor' that give
run-time type information. */
int flag_rtti = 1;
/* Nonzero if we want to conserve space in the .o files. We do this
by putting uninitialized data and runtime initialized data into
.common instead of .data at the expense of not flagging multiple
definitions. */
int flag_conserve_space;
/* Nonzero if we want to obey access control semantics. */
int flag_access_control = 1;
/* Nonzero if we want to check the return value of new and avoid calling
constructors if it is a null pointer. */
int flag_check_new;
/* Nonzero if we want the new ISO rules for pushing a new scope for `for'
initialization variables.
0: Old rules, set by -fno-for-scope.
2: New ISO rules, set by -ffor-scope.
1: Try to implement new ISO rules, but with backup compatibility
(and warnings). This is the default, for now. */
int flag_new_for_scope = 1;
/* Nonzero if we want to emit defined symbols with common-like linkage as
weak symbols where possible, in order to conform to C++ semantics.
Otherwise, emit them as local symbols. */
int flag_weak = 1;
/* Nonzero to use __cxa_atexit, rather than atexit, to register
destructors for local statics and global objects. */
int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT;
/* Nonzero means output .vtable_{entry,inherit} for use in doing vtable gc. */
int flag_vtable_gc;
/* Nonzero means make the default pedwarns warnings instead of errors.
The value of this flag is ignored if -pedantic is specified. */
int flag_permissive;
/* Nonzero means to implement standard semantics for exception
specifications, calling unexpected if an exception is thrown that
doesn't match the specification. Zero means to treat them as
assertions and optimize accordingly, but not check them. */
int flag_enforce_eh_specs = 1;
/* The version of the C++ ABI in use. The following values are
0: The version of the ABI believed most conformant with the
C++ ABI specification. This ABI may change as bugs are
discovered and fixed. Therefore, 0 will not necessarily
indicate the same ABI in different versions of G++.
1: The version of the ABI first used in G++ 3.2.
Additional positive integers will be assigned as new versions of
the ABI become the default version of the ABI. */
int flag_abi_version = 1;
/* Nonzero means warn about things that will change when compiling
with an ABI-compliant compiler. */
int warn_abi = 0;
/* Nonzero means warn about implicit declarations. */
int warn_implicit = 1;
/* Nonzero means warn when all ctors or dtors are private, and the class
has no friends. */
int warn_ctor_dtor_privacy = 1;
/* Nonzero means warn in function declared in derived class has the
same name as a virtual in the base class, but fails to match the
type signature of any virtual function in the base class. */
int warn_overloaded_virtual;
/* Nonzero means warn when declaring a class that has a non virtual
destructor, when it really ought to have a virtual one. */
int warn_nonvdtor;
/* Nonzero means warn when the compiler will reorder code. */
int warn_reorder;
/* Nonzero means warn when synthesis behavior differs from Cfront's. */
int warn_synth;
/* Nonzero means warn when we convert a pointer to member function
into a pointer to (void or function). */
int warn_pmf2ptr = 1;
/* Nonzero means warn about violation of some Effective C++ style rules. */
int warn_ecpp;
/* Nonzero means warn where overload resolution chooses a promotion from
unsigned to signed over a conversion to an unsigned of the same size. */
int warn_sign_promo;
/* Nonzero means warn when an old-style cast is used. */
int warn_old_style_cast;
/* Nonzero means warn when non-templatized friend functions are
declared within a template */
int warn_nontemplate_friend = 1;
/* Nonzero means complain about deprecated features. */
int warn_deprecated = 1;
/* Maximum template instantiation depth. This limit is rather
arbitrary, but it exists to limit the time it takes to notice
infinite template instantiations. */
int max_tinst_depth = 500;
/* The elements of `ridpointers' are identifier nodes for the reserved
type names and storage classes. It is indexed by a RID_... value. */
tree *ridpointers;
tree (*make_fname_decl) PARAMS ((tree, int));
/* If non-NULL, the address of a language-specific function that
returns 1 for language-specific statement codes. */
int (*lang_statement_code_p) PARAMS ((enum tree_code));
/* If non-NULL, the address of a language-specific function that takes
any action required right before expand_function_end is called. */
void (*lang_expand_function_end) PARAMS ((void));
/* Nonzero means the expression being parsed will never be evaluated.
This is a count, since unevaluated expressions can nest. */
int skip_evaluation;
/* Information about how a function name is generated. */
struct fname_var_t
tree *const decl; /* pointer to the VAR_DECL. */
const unsigned rid; /* RID number for the identifier. */
const int pretty; /* How pretty is it? */
/* The three ways of getting then name of the current function. */
const struct fname_var_t fname_vars[] =
/* C99 compliant __func__, must be first. */
{&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0},
/* GCC __FUNCTION__ compliant. */
{&function_name_decl_node, RID_FUNCTION_NAME, 0},
/* GCC __PRETTY_FUNCTION__ compliant. */
{&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1},
{NULL, 0, 0},
static int constant_fits_type_p PARAMS ((tree, tree));
/* Keep a stack of if statements. We record the number of compound
statements seen up to the if keyword, as well as the line number
and file of the if. If a potentially ambiguous else is seen, that
fact is recorded; the warning is issued when we can be sure that
the enclosing if statement does not have an else branch. */
typedef struct
int compstmt_count;
int line;
const char *file;
int needs_warning;
tree if_stmt;
} if_elt;
static if_elt *if_stack;
/* Amount of space in the if statement stack. */
static int if_stack_space = 0;
/* Stack pointer. */
static int if_stack_pointer = 0;
static tree handle_packed_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_nocommon_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_common_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_noreturn_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_noinline_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_always_inline_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_used_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_unused_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_const_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_transparent_union_attribute PARAMS ((tree *, tree, tree,
int, bool *));
static tree handle_constructor_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_destructor_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_mode_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_section_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_aligned_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_weak_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_alias_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_visibility_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_tls_model_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_no_instrument_function_attribute PARAMS ((tree *, tree,
tree, int,
bool *));
static tree handle_malloc_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_no_limit_stack_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_pure_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_deprecated_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_vector_size_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_nonnull_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_nothrow_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree handle_cleanup_attribute PARAMS ((tree *, tree, tree, int,
bool *));
static tree vector_size_helper PARAMS ((tree, tree));
static void check_function_nonnull PARAMS ((tree, tree));
static void check_nonnull_arg PARAMS ((void *, tree,
unsigned HOST_WIDE_INT));
static bool nonnull_check_p PARAMS ((tree, unsigned HOST_WIDE_INT));
static bool get_nonnull_operand PARAMS ((tree,
unsigned HOST_WIDE_INT *));
void builtin_define_std PARAMS ((const char *));
static void builtin_define_with_value PARAMS ((const char *, const char *,
static void builtin_define_with_int_value PARAMS ((const char *,
static void builtin_define_with_hex_fp_value PARAMS ((const char *, tree,
int, const char *,
const char *));
static void builtin_define_type_max PARAMS ((const char *, tree, int));
static void builtin_define_type_precision PARAMS ((const char *, tree));
static void builtin_define_float_constants PARAMS ((const char *,
const char *, tree));
/* Table of machine-independent attributes common to all C-like languages. */
const struct attribute_spec c_common_attribute_table[] =
/* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
{ "packed", 0, 0, false, false, false,
handle_packed_attribute },
{ "nocommon", 0, 0, true, false, false,
handle_nocommon_attribute },
{ "common", 0, 0, true, false, false,
handle_common_attribute },
/* FIXME: logically, noreturn attributes should be listed as
"false, true, true" and apply to function types. But implementing this
would require all the places in the compiler that use TREE_THIS_VOLATILE
on a decl to identify non-returning functions to be located and fixed
to check the function type instead. */
{ "noreturn", 0, 0, true, false, false,
handle_noreturn_attribute },
{ "volatile", 0, 0, true, false, false,
handle_noreturn_attribute },
{ "noinline", 0, 0, true, false, false,
handle_noinline_attribute },
{ "always_inline", 0, 0, true, false, false,
handle_always_inline_attribute },
{ "used", 0, 0, true, false, false,
handle_used_attribute },
{ "unused", 0, 0, false, false, false,
handle_unused_attribute },
/* The same comments as for noreturn attributes apply to const ones. */
{ "const", 0, 0, true, false, false,
handle_const_attribute },
{ "transparent_union", 0, 0, false, false, false,
handle_transparent_union_attribute },
{ "constructor", 0, 0, true, false, false,
handle_constructor_attribute },
{ "destructor", 0, 0, true, false, false,
handle_destructor_attribute },
{ "mode", 1, 1, false, true, false,
handle_mode_attribute },
{ "section", 1, 1, true, false, false,
handle_section_attribute },
{ "aligned", 0, 1, false, false, false,
handle_aligned_attribute },
{ "weak", 0, 0, true, false, false,
handle_weak_attribute },
{ "alias", 1, 1, true, false, false,
handle_alias_attribute },
{ "no_instrument_function", 0, 0, true, false, false,
handle_no_instrument_function_attribute },
{ "malloc", 0, 0, true, false, false,
handle_malloc_attribute },
{ "no_stack_limit", 0, 0, true, false, false,
handle_no_limit_stack_attribute },
{ "pure", 0, 0, true, false, false,
handle_pure_attribute },
{ "deprecated", 0, 0, false, false, false,
handle_deprecated_attribute },
{ "vector_size", 1, 1, false, true, false,
handle_vector_size_attribute },
{ "visibility", 1, 1, true, false, false,
handle_visibility_attribute },
{ "tls_model", 1, 1, true, false, false,
handle_tls_model_attribute },
{ "nonnull", 0, -1, false, true, true,
handle_nonnull_attribute },
{ "nothrow", 0, 0, true, false, false,
handle_nothrow_attribute },
{ "may_alias", 0, 0, false, true, false, NULL },
{ "cleanup", 1, 1, true, false, false,
handle_cleanup_attribute },
{ NULL, 0, 0, false, false, false, NULL }
/* Give the specifications for the format attributes, used by C and all
descendents. */
const struct attribute_spec c_common_format_attribute_table[] =
/* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
{ "format", 3, 3, false, true, true,
handle_format_attribute },
{ "format_arg", 1, 1, false, true, true,
handle_format_arg_attribute },
{ NULL, 0, 0, false, false, false, NULL }
/* Record the start of an if-then, and record the start of it
for ambiguous else detection.
COND is the condition for the if-then statement.
IF_STMT is the statement node that has already been created for
this if-then statement. It is created before parsing the
condition to keep line number information accurate. */
c_expand_start_cond (cond, compstmt_count, if_stmt)
tree cond;
int compstmt_count;
tree if_stmt;
/* Make sure there is enough space on the stack. */
if (if_stack_space == 0)
if_stack_space = 10;
if_stack = (if_elt *) xmalloc (10 * sizeof (if_elt));
else if (if_stack_space == if_stack_pointer)
if_stack_space += 10;
if_stack = (if_elt *) xrealloc (if_stack, if_stack_space * sizeof (if_elt));
IF_COND (if_stmt) = cond;
add_stmt (if_stmt);
/* Record this if statement. */
if_stack[if_stack_pointer].compstmt_count = compstmt_count;
if_stack[if_stack_pointer].file = input_filename;
if_stack[if_stack_pointer].line = lineno;
if_stack[if_stack_pointer].needs_warning = 0;
if_stack[if_stack_pointer].if_stmt = if_stmt;
/* Called after the then-clause for an if-statement is processed. */
c_finish_then ()
tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
RECHAIN_STMTS (if_stmt, THEN_CLAUSE (if_stmt));
/* Record the end of an if-then. Optionally warn if a nested
if statement had an ambiguous else clause. */
c_expand_end_cond ()
if (if_stack[if_stack_pointer].needs_warning)
warning_with_file_and_line (if_stack[if_stack_pointer].file,
"suggest explicit braces to avoid ambiguous `else'");
last_expr_type = NULL_TREE;
/* Called between the then-clause and the else-clause
of an if-then-else. */
c_expand_start_else ()
/* An ambiguous else warning must be generated for the enclosing if
statement, unless we see an else branch for that one, too. */
if (warn_parentheses
&& if_stack_pointer > 1
&& (if_stack[if_stack_pointer - 1].compstmt_count
== if_stack[if_stack_pointer - 2].compstmt_count))
if_stack[if_stack_pointer - 2].needs_warning = 1;
/* Even if a nested if statement had an else branch, it can't be
ambiguous if this one also has an else. So don't warn in that
case. Also don't warn for any if statements nested in this else. */
if_stack[if_stack_pointer - 1].needs_warning = 0;
if_stack[if_stack_pointer - 1].compstmt_count--;
/* Called after the else-clause for an if-statement is processed. */
c_finish_else ()
tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
RECHAIN_STMTS (if_stmt, ELSE_CLAUSE (if_stmt));
/* Begin an if-statement. Returns a newly created IF_STMT if
Unlike the C++ front-end, we do not call add_stmt here; it is
probably safe to do so, but I am not very familiar with this
code so I am being extra careful not to change its behavior
beyond what is strictly necessary for correctness. */
c_begin_if_stmt ()
tree r;
return r;
/* Begin a while statement. Returns a newly created WHILE_STMT if
Unlike the C++ front-end, we do not call add_stmt here; it is
probably safe to do so, but I am not very familiar with this
code so I am being extra careful not to change its behavior
beyond what is strictly necessary for correctness. */
c_begin_while_stmt ()
tree r;
r = build_stmt (WHILE_STMT, NULL_TREE, NULL_TREE);
return r;
c_finish_while_stmt_cond (cond, while_stmt)
tree while_stmt;
tree cond;
WHILE_COND (while_stmt) = cond;
/* Push current bindings for the function name VAR_DECLS. */
start_fname_decls ()
unsigned ix;
tree saved = NULL_TREE;
for (ix = 0; fname_vars[ix].decl; ix++)
tree decl = *fname_vars[ix].decl;
if (decl)
saved = tree_cons (decl, build_int_2 (ix, 0), saved);
*fname_vars[ix].decl = NULL_TREE;
if (saved || saved_function_name_decls)
/* Normally they'll have been NULL, so only push if we've got a
stack, or they are non-NULL. */
saved_function_name_decls = tree_cons (saved, NULL_TREE,
/* Finish up the current bindings, adding them into the
current function's statement tree. This is done by wrapping the
function's body in a COMPOUND_STMT containing these decls too. This
must be done _before_ finish_stmt_tree is called. If there is no
current function, we must be at file scope and no statements are
involved. Pop the previous bindings. */
finish_fname_decls ()
unsigned ix;
tree body = NULL_TREE;
tree stack = saved_function_name_decls;
for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack))
body = chainon (TREE_VALUE (stack), body);
if (body)
/* They were called into existence, so add to statement tree. */
body = chainon (body,
TREE_CHAIN (DECL_SAVED_TREE (current_function_decl)));
body = build_stmt (COMPOUND_STMT, body);
TREE_CHAIN (DECL_SAVED_TREE (current_function_decl)) = body;
for (ix = 0; fname_vars[ix].decl; ix++)
*fname_vars[ix].decl = NULL_TREE;
if (stack)
/* We had saved values, restore them. */
tree saved;
for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved))
tree decl = TREE_PURPOSE (saved);
unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved));
*fname_vars[ix].decl = decl;
stack = TREE_CHAIN (stack);
saved_function_name_decls = stack;
/* Return the text name of the current function, suitable prettified
by PRETTY_P. */
const char *
fname_as_string (pretty_p)
int pretty_p;
const char *name = NULL;
if (pretty_p)
name = (current_function_decl
? (*lang_hooks.decl_printable_name) (current_function_decl, 2)
: "top level");
else if (current_function_decl && DECL_NAME (current_function_decl))
name = IDENTIFIER_POINTER (DECL_NAME (current_function_decl));
name = "";
return name;
/* Return the text name of the current function, formatted as
required by the supplied RID value. */
const char *
fname_string (rid)
unsigned rid;
unsigned ix;
for (ix = 0; fname_vars[ix].decl; ix++)
if (fname_vars[ix].rid == rid)
return fname_as_string (fname_vars[ix].pretty);
/* Return the VAR_DECL for a const char array naming the current
function. If the VAR_DECL has not yet been created, create it
now. RID indicates how it should be formatted and IDENTIFIER_NODE
ID is its name (unfortunately C and C++ hold the RID values of
keywords in different places, so we can't derive RID from ID in
this language independent code. */
fname_decl (rid, id)
unsigned rid;
tree id;
unsigned ix;
tree decl = NULL_TREE;
for (ix = 0; fname_vars[ix].decl; ix++)
if (fname_vars[ix].rid == rid)
decl = *fname_vars[ix].decl;
if (!decl)
tree saved_last_tree = last_tree;
/* If a tree is built here, it would normally have the lineno of
the current statement. Later this tree will be moved to the
beginning of the function and this line number will be wrong.
To avoid this problem set the lineno to 0 here; that prevents
it from appearing in the RTL. */
int saved_lineno = lineno;
lineno = 0;
decl = (*make_fname_decl) (id, fname_vars[ix].pretty);
if (last_tree != saved_last_tree)
/* We created some statement tree for the decl. This belongs
at the start of the function, so remove it now and reinsert
it after the function is complete. */
tree stmts = TREE_CHAIN (saved_last_tree);
TREE_CHAIN (saved_last_tree) = NULL_TREE;
last_tree = saved_last_tree;
saved_function_name_decls = tree_cons (decl, stmts,
*fname_vars[ix].decl = decl;
lineno = saved_lineno;
if (!ix && !current_function_decl)
pedwarn_with_decl (decl, "`%s' is not defined outside of function scope");
return decl;
/* Given a STRING_CST, give it a suitable array-of-chars data type. */
fix_string_type (value)
tree value;
const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
const int wide_flag = TREE_TYPE (value) == wchar_array_type_node;
const int nchars_max = flag_isoc99 ? 4095 : 509;
int length = TREE_STRING_LENGTH (value);
int nchars;
/* Compute the number of elements, for the array type. */
nchars = wide_flag ? length / wchar_bytes : length;
if (pedantic && nchars - 1 > nchars_max && c_language == clk_c)
pedwarn ("string length `%d' is greater than the length `%d' ISO C%d compilers are required to support",
nchars - 1, nchars_max, flag_isoc99 ? 99 : 89);
/* Create the array type for the string constant.
-Wwrite-strings says make the string constant an array of const char
so that copying it to a non-const pointer will get a warning.
For C++, this is the standard behavior. */
if (flag_const_strings && ! flag_writable_strings)
tree elements
= build_type_variant (wide_flag ? wchar_type_node : char_type_node,
1, 0);
TREE_TYPE (value)
= build_array_type (elements,
build_index_type (build_int_2 (nchars - 1, 0)));
TREE_TYPE (value)
= build_array_type (wide_flag ? wchar_type_node : char_type_node,
build_index_type (build_int_2 (nchars - 1, 0)));
TREE_CONSTANT (value) = 1;
TREE_READONLY (value) = ! flag_writable_strings;
TREE_STATIC (value) = 1;
return value;
/* Given a VARRAY of STRING_CST nodes, concatenate them into one
combine_strings (strings)
varray_type strings;
const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
const int nstrings = VARRAY_ACTIVE_SIZE (strings);
tree value, t;
int length = 1;
int wide_length = 0;
int wide_flag = 0;
int i;
char *p, *q;
/* Don't include the \0 at the end of each substring. Count wide
strings and ordinary strings separately. */
for (i = 0; i < nstrings; ++i)
t = VARRAY_TREE (strings, i);
if (TREE_TYPE (t) == wchar_array_type_node)
wide_length += TREE_STRING_LENGTH (t) - wchar_bytes;
wide_flag = 1;
length += (TREE_STRING_LENGTH (t) - 1);
if (C_ARTIFICIAL_STRING_P (t) && !in_system_header)
warning ("concatenation of string literals with __FUNCTION__ is deprecated");
/* If anything is wide, the non-wides will be converted,
which makes them take more space. */
if (wide_flag)
length = length * wchar_bytes + wide_length;
p = xmalloc (length);
/* Copy the individual strings into the new combined string.
If the combined string is wide, convert the chars to ints
for any individual strings that are not wide. */
q = p;
for (i = 0; i < nstrings; ++i)
int len, this_wide;
t = VARRAY_TREE (strings, i);
this_wide = TREE_TYPE (t) == wchar_array_type_node;
len = TREE_STRING_LENGTH (t) - (this_wide ? wchar_bytes : 1);
if (this_wide == wide_flag)
memcpy (q, TREE_STRING_POINTER (t), len);
q += len;
const int nzeros = (TYPE_PRECISION (wchar_type_node)
int j, k;
for (k = 0; k < len; k++)
for (j = 0; j < nzeros; j++)
*q++ = 0;
*q++ = TREE_STRING_POINTER (t)[k];
for (k = 0; k < len; k++)
*q++ = TREE_STRING_POINTER (t)[k];
for (j = 0; j < nzeros; j++)
*q++ = 0;
/* Nul terminate the string. */
if (wide_flag)
for (i = 0; i < wchar_bytes; i++)
*q++ = 0;
*q = 0;
value = build_string (length, p);
free (p);
if (wide_flag)
TREE_TYPE (value) = wchar_array_type_node;
TREE_TYPE (value) = char_array_type_node;
return value;
static int is_valid_printf_arglist PARAMS ((tree));
static rtx c_expand_builtin PARAMS ((tree, rtx, enum machine_mode, enum expand_modifier));
static rtx c_expand_builtin_printf PARAMS ((tree, rtx, enum machine_mode,
enum expand_modifier, int, int));
static rtx c_expand_builtin_fprintf PARAMS ((tree, rtx, enum machine_mode,
enum expand_modifier, int, int));
/* Print a warning if a constant expression had overflow in folding.
Invoke this function on every expression that the language
requires to be a constant expression.
Note the ANSI C standard says it is erroneous for a
constant expression to overflow. */
constant_expression_warning (value)
tree value;
if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
|| TREE_CODE (value) == VECTOR_CST
|| TREE_CODE (value) == COMPLEX_CST)
&& TREE_CONSTANT_OVERFLOW (value) && pedantic)
pedwarn ("overflow in constant expression");
/* Print a warning if an expression had overflow in folding.
Invoke this function on every expression that
(1) appears in the source code, and
(2) might be a constant expression that overflowed, and
(3) is not already checked by convert_and_check;
however, do not invoke this function on operands of explicit casts. */
overflow_warning (value)
tree value;
if ((TREE_CODE (value) == INTEGER_CST
|| (TREE_CODE (value) == COMPLEX_CST
&& TREE_OVERFLOW (value))
TREE_OVERFLOW (value) = 0;
if (skip_evaluation == 0)
warning ("integer overflow in expression");
else if ((TREE_CODE (value) == REAL_CST
|| (TREE_CODE (value) == COMPLEX_CST
&& TREE_OVERFLOW (value))
TREE_OVERFLOW (value) = 0;
if (skip_evaluation == 0)
warning ("floating point overflow in expression");
else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value))
TREE_OVERFLOW (value) = 0;
if (skip_evaluation == 0)
warning ("vector overflow in expression");
/* Print a warning if a large constant is truncated to unsigned,
or if -Wconversion is used and a constant < 0 is converted to unsigned.
Invoke this function on every expression that might be implicitly
converted to an unsigned type. */
unsigned_conversion_warning (result, operand)
tree result, operand;
tree type = TREE_TYPE (result);
if (TREE_CODE (operand) == INTEGER_CST
&& skip_evaluation == 0
&& !int_fits_type_p (operand, type))
if (!int_fits_type_p (operand, c_common_signed_type (type)))
/* This detects cases like converting -129 or 256 to unsigned char. */
warning ("large integer implicitly truncated to unsigned type");
else if (warn_conversion)
warning ("negative integer implicitly converted to unsigned type");
/* Nonzero if constant C has a value that is permissible
for type TYPE (an INTEGER_TYPE). */
static int
constant_fits_type_p (c, type)
tree c, type;
return int_fits_type_p (c, type);
c = convert (type, c);
return !TREE_OVERFLOW (c);
/* Convert EXPR to TYPE, warning about conversion problems with constants.
Invoke this function on every expression that is converted implicitly,
i.e. because of language rules and not because of an explicit cast. */
convert_and_check (type, expr)
tree type, expr;
tree t = convert (type, expr);
/* Do not diagnose overflow in a constant expression merely
because a conversion overflowed. */
/* No warning for converting 0x80000000 to int. */
/* If EXPR fits in the unsigned version of TYPE,
don't warn unless pedantic. */
if ((pedantic
|| ! constant_fits_type_p (expr,
c_common_unsigned_type (type)))
&& skip_evaluation == 0)
warning ("overflow in implicit constant conversion");
unsigned_conversion_warning (t, expr);
return t;
/* A node in a list that describes references to variables (EXPR), which are
either read accesses if WRITER is zero, or write accesses, in which case
WRITER is the parent of EXPR. */
struct tlist
struct tlist *next;
tree expr, writer;
/* Used to implement a cache the results of a call to verify_tree. We only
use this for SAVE_EXPRs. */
struct tlist_cache
struct tlist_cache *next;
struct tlist *cache_before_sp;
struct tlist *cache_after_sp;
tree expr;
/* Obstack to use when allocating tlist structures, and corresponding
firstobj. */
static struct obstack tlist_obstack;
static char *tlist_firstobj = 0;
/* Keep track of the identifiers we've warned about, so we can avoid duplicate
warnings. */
static struct tlist *warned_ids;
/* SAVE_EXPRs need special treatment. We process them only once and then
cache the results. */
static struct tlist_cache *save_expr_cache;
static void add_tlist PARAMS ((struct tlist **, struct tlist *, tree, int));
static void merge_tlist PARAMS ((struct tlist **, struct tlist *, int));
static void verify_tree PARAMS ((tree, struct tlist **, struct tlist **, tree));
static int warning_candidate_p PARAMS ((tree));
static void warn_for_collisions PARAMS ((struct tlist *));
static void warn_for_collisions_1 PARAMS ((tree, tree, struct tlist *, int));
static struct tlist *new_tlist PARAMS ((struct tlist *, tree, tree));
static void verify_sequence_points PARAMS ((tree));
/* Create a new struct tlist and fill in its fields. */
static struct tlist *
new_tlist (next, t, writer)
struct tlist *next;
tree t;
tree writer;
struct tlist *l;
l = (struct tlist *) obstack_alloc (&tlist_obstack, sizeof *l);
l->next = next;
l->expr = t;
l->writer = writer;
return l;
/* Add duplicates of the nodes found in ADD to the list *TO. If EXCLUDE_WRITER
is nonnull, we ignore any node we find which has a writer equal to it. */
static void
add_tlist (to, add, exclude_writer, copy)
struct tlist **to;
struct tlist *add;
tree exclude_writer;
int copy;
while (add)
struct tlist *next = add->next;
if (! copy)
add->next = *to;
if (! exclude_writer || add->writer != exclude_writer)
*to = copy ? new_tlist (*to, add->expr, add->writer) : add;
add = next;
/* Merge the nodes of ADD into TO. This merging process is done so that for
each variable that already exists in TO, no new node is added; however if
there is a write access recorded in ADD, and an occurrence on TO is only
a read access, then the occurrence in TO will be modified to record the
write. */
static void
merge_tlist (to, add, copy)
struct tlist **to;
struct tlist *add;
int copy;
struct tlist **end = to;
while (*end)
end = &(*end)->next;
while (add)
int found = 0;
struct tlist *tmp2;
struct tlist *next = add->next;
for (tmp2 = *to; tmp2; tmp2 = tmp2->next)
if (tmp2->expr == add->expr)
found = 1;
if (! tmp2->writer)
tmp2->writer = add->writer;
if (! found)
*end = copy ? add : new_tlist (NULL, add->expr, add->writer);
end = &(*end)->next;
*end = 0;
add = next;
/* WRITTEN is a variable, WRITER is its parent. Warn if any of the variable
references in list LIST conflict with it, excluding reads if ONLY writers
is nonzero. */
static void
warn_for_collisions_1 (written, writer, list, only_writes)
tree written, writer;
struct tlist *list;
int only_writes;
struct tlist *tmp;
/* Avoid duplicate warnings. */
for (tmp = warned_ids; tmp; tmp = tmp->next)
if (tmp->expr == written)
while (list)
if (list->expr == written
&& list->writer != writer
&& (! only_writes || list->writer))
warned_ids = new_tlist (warned_ids, written, NULL_TREE);
warning ("operation on `%s' may be undefined",
list = list->next;
/* Given a list LIST of references to variables, find whether any of these
can cause conflicts due to missing sequence points. */
static void
warn_for_collisions (list)
struct tlist *list;
struct tlist *tmp;
for (tmp = list; tmp; tmp = tmp->next)
if (tmp->writer)
warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0);
/* Return nonzero if X is a tree that can be verified by the sequence point
warnings. */
static int
warning_candidate_p (x)
tree x;
return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL;
/* Walk the tree X, and record accesses to variables. If X is written by the
parent tree, WRITER is the parent.
We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP. If this
expression or its only operand forces a sequence point, then everything up
to the sequence point is stored in PBEFORE_SP. Everything else gets stored
in PNO_SP.
Once we return, we will have emitted warnings if any subexpression before
such a sequence point could be undefined. On a higher level, however, the
sequence point may not be relevant, and we'll merge the two lists.
Example: (b++, a) + b;
The call that processes the COMPOUND_EXPR will store the increment of B
in PBEFORE_SP, and the use of A in PNO_SP. The higher-level call that
processes the PLUS_EXPR will need to merge the two lists so that
eventually, all accesses end up on the same list (and we'll warn about the
unordered subexpressions b++ and b.
A note on merging. If we modify the former example so that our expression
(b++, b) + a
care must be taken not simply to add all three expressions into the final
PNO_SP list. The function merge_tlist takes care of that by merging the
before-SP list of the COMPOUND_EXPR into its after-SP list in a special
way, so that no more than one access to B is recorded. */
static void
verify_tree (x, pbefore_sp, pno_sp, writer)
tree x;
struct tlist **pbefore_sp, **pno_sp;
tree writer;
struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3;
enum tree_code code;
char class;
/* X may be NULL if it is the operand of an empty statement expression
({ }). */
if (x == NULL)
code = TREE_CODE (x);
class = TREE_CODE_CLASS (code);
if (warning_candidate_p (x))
*pno_sp = new_tlist (*pno_sp, x, writer);
switch (code)
tmp_before = tmp_nosp = tmp_list3 = 0;
verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
warn_for_collisions (tmp_nosp);
merge_tlist (pbefore_sp, tmp_before, 0);
merge_tlist (pbefore_sp, tmp_nosp, 0);
verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE);
merge_tlist (pbefore_sp, tmp_list3, 0);
tmp_before = tmp_list2 = 0;
verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE);
warn_for_collisions (tmp_list2);
merge_tlist (pbefore_sp, tmp_before, 0);
merge_tlist (pbefore_sp, tmp_list2, 1);
tmp_list3 = tmp_nosp = 0;
verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE);
warn_for_collisions (tmp_nosp);
merge_tlist (pbefore_sp, tmp_list3, 0);
tmp_list3 = tmp_list2 = 0;
verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE);
warn_for_collisions (tmp_list2);
merge_tlist (pbefore_sp, tmp_list3, 0);
/* Rather than add both tmp_nosp and tmp_list2, we have to merge the
two first, to avoid warning for (a ? b++ : b++). */
merge_tlist (&tmp_nosp, tmp_list2, 0);
add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x);
tmp_before = tmp_nosp = tmp_list3 = 0;
verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE);
verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x);
/* Expressions inside the LHS are not ordered wrt. the sequence points
in the RHS. Example:
*a = (a++, 2)
Despite the fact that the modification of "a" is in the before_sp
list (tmp_before), it conflicts with the use of "a" in the LHS.
We can handle this by adding the contents of tmp_list3
to those of tmp_before, and redoing the collision warnings for that
list. */
add_tlist (&tmp_before, tmp_list3, x, 1);
warn_for_collisions (tmp_before);
/* Exclude the LHS itself here; we first have to merge it into the
tmp_nosp list. This is done to avoid warning for "a = a"; if we
didn't exclude the LHS, we'd get it twice, once as a read and once
as a write. */
add_tlist (pno_sp, tmp_list3, x, 0);
warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1);
merge_tlist (pbefore_sp, tmp_before, 0);
if (warning_candidate_p (TREE_OPERAND (x, 0)))
merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0);
add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1);
/* We need to warn about conflicts among arguments and conflicts between
args and the function address. Side effects of the function address,
however, are not ordered by the sequence point of the call. */
tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0;
verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
if (TREE_OPERAND (x, 1))
verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE);
merge_tlist (&tmp_list3, tmp_list2, 0);
add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0);
add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0);
warn_for_collisions (tmp_before);
add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0);
/* Scan all the list, e.g. indices of multi dimensional array. */
while (x)
tmp_before = tmp_nosp = 0;
verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE);
merge_tlist (&tmp_nosp, tmp_before, 0);
add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
x = TREE_CHAIN (x);
struct tlist_cache *t;
for (t = save_expr_cache; t; t = t->next)
if (t->expr == x)
if (! t)
t = (struct tlist_cache *) obstack_alloc (&tlist_obstack,
sizeof *t);
t->next = save_expr_cache;
t->expr = x;
save_expr_cache = t;
tmp_before = tmp_nosp = 0;
verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE);
warn_for_collisions (tmp_nosp);
tmp_list3 = 0;
while (tmp_nosp)
struct tlist *t = tmp_nosp;
tmp_nosp = t->next;
merge_tlist (&tmp_list3, t, 0);
t->cache_before_sp = tmp_before;
t->cache_after_sp = tmp_list3;
merge_tlist (pbefore_sp, t->cache_before_sp, 1);
add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1);
if (class == '1')
if (first_rtl_op (code) == 0)
x = TREE_OPERAND (x, 0);
writer = 0;
goto restart;
switch (class)
case 'r':
case '<':
case '2':
case 'b':
case 'e':
case 's':
case 'x':
int lp;
int max = first_rtl_op (TREE_CODE (x));
for (lp = 0; lp < max; lp++)
tmp_before = tmp_nosp = 0;
verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, NULL_TREE);
merge_tlist (&tmp_nosp, tmp_before, 0);
add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0);
/* Try to warn for undefined behavior in EXPR due to missing sequence
points. */
static void
verify_sequence_points (expr)
tree expr;
struct tlist *before_sp = 0, *after_sp = 0;
warned_ids = 0;
save_expr_cache = 0;
if (tlist_firstobj == 0)
gcc_obstack_init (&tlist_obstack);
tlist_firstobj = obstack_alloc (&tlist_obstack, 0);
verify_tree (expr, &before_sp, &after_sp, 0);
warn_for_collisions (after_sp);
obstack_free (&tlist_obstack, tlist_firstobj);
c_expand_expr_stmt (expr)
tree expr;
/* Do default conversion if safe and possibly important,
in case within ({...}). */
&& (flag_isoc99 || lvalue_p (expr)))
expr = default_conversion (expr);
if (warn_sequence_point)
verify_sequence_points (expr);
if (TREE_TYPE (expr) != error_mark_node
error ("expression statement has incomplete type");
last_expr_type = TREE_TYPE (expr);
return add_stmt (build_stmt (EXPR_STMT, expr));
/* Validate the expression after `case' and apply default promotions. */
check_case_value (value)
tree value;
if (value == NULL_TREE)
return value;
/* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
/* In C++, the following is allowed:
const int i = 3;
switch (...) { case i: ... }
So, we try to reduce the VALUE to a constant that way. */
if (c_language == clk_cplusplus)
value = decl_constant_value (value);
value = fold (value);
if (TREE_CODE (value) != INTEGER_CST
&& value != error_mark_node)
error ("case label does not reduce to an integer constant");
value = error_mark_node;
/* Promote char or short to int. */
value = default_conversion (value);
constant_expression_warning (value);
return value;
/* Return an integer type with BITS bits of precision,
that is unsigned if UNSIGNEDP is nonzero, otherwise signed. */
c_common_type_for_size (bits, unsignedp)
unsigned bits;
int unsignedp;
if (bits == TYPE_PRECISION (integer_type_node))
return unsignedp ? unsigned_type_node : integer_type_node;
if (bits == TYPE_PRECISION (signed_char_type_node))
return unsignedp ? unsigned_char_type_node : signed_char_type_node;
if (bits == TYPE_PRECISION (short_integer_type_node))
return unsignedp ? short_unsigned_type_node : short_integer_type_node;
if (bits == TYPE_PRECISION (long_integer_type_node))
return unsignedp ? long_unsigned_type_node : long_integer_type_node;
if (bits == TYPE_PRECISION (long_long_integer_type_node))
return (unsignedp ? long_long_unsigned_type_node
: long_long_integer_type_node);
if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
return (unsignedp ? widest_unsigned_literal_type_node
: widest_integer_literal_type_node);
if (bits <= TYPE_PRECISION (intQI_type_node))
return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
if (bits <= TYPE_PRECISION (intHI_type_node))
return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
if (bits <= TYPE_PRECISION (intSI_type_node))
return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
if (bits <= TYPE_PRECISION (intDI_type_node))
return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
return 0;
/* Return a data type that has machine mode MODE.
If the mode is an integer,
then UNSIGNEDP selects between signed and unsigned types. */
c_common_type_for_mode (mode, unsignedp)
enum machine_mode mode;
int unsignedp;
if (mode == TYPE_MODE (integer_type_node))
return unsignedp ? unsigned_type_node : integer_type_node;
if (mode == TYPE_MODE (signed_char_type_node))
return unsignedp ? unsigned_char_type_node : signed_char_type_node;
if (mode == TYPE_MODE (short_integer_type_node))
return unsignedp ? short_unsigned_type_node : short_integer_type_node;
if (mode == TYPE_MODE (long_integer_type_node))
return unsignedp ? long_unsigned_type_node : long_integer_type_node;
if (mode == TYPE_MODE (long_long_integer_type_node))
return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
if (mode == TYPE_MODE (widest_integer_literal_type_node))
return unsignedp ? widest_unsigned_literal_type_node
: widest_integer_literal_type_node;
if (mode == QImode)
return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
if (mode == HImode)
return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
if (mode == SImode)
return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
if (mode == DImode)
return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
if (mode == TYPE_MODE (intTI_type_node))
return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
if (mode == TYPE_MODE (float_type_node))
return float_type_node;
if (mode == TYPE_MODE (double_type_node))
return double_type_node;
if (mode == TYPE_MODE (long_double_type_node))
return long_double_type_node;
if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
return build_pointer_type (char_type_node);
if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
return build_pointer_type (integer_type_node);
switch (mode)
case V16QImode:
return unsignedp ? unsigned_V16QI_type_node : V16QI_type_node;
case V8HImode:
return unsignedp ? unsigned_V8HI_type_node : V8HI_type_node;
case V4SImode:
return unsignedp ? unsigned_V4SI_type_node : V4SI_type_node;
case V2DImode:
return unsignedp ? unsigned_V2DI_type_node : V2DI_type_node;
case V2SImode:
return unsignedp ? unsigned_V2SI_type_node : V2SI_type_node;
case V2HImode:
return unsignedp ? unsigned_V2HI_type_node : V2HI_type_node;
case V4HImode:
return unsignedp ? unsigned_V4HI_type_node : V4HI_type_node;
case V8QImode:
return unsignedp ? unsigned_V8QI_type_node : V8QI_type_node;
case V1DImode:
return unsignedp ? unsigned_V1DI_type_node : V1DI_type_node;
case V16SFmode:
return V16SF_type_node;
case V4SFmode:
return V4SF_type_node;
case V2SFmode:
return V2SF_type_node;
case V2DFmode:
return V2DF_type_node;
return 0;
/* Return an unsigned type the same as TYPE in other respects. */
c_common_unsigned_type (type)
tree type;
tree type1 = TYPE_MAIN_VARIANT (type);
if (type1 == signed_char_type_node || type1 == char_type_node)
return unsigned_char_type_node;
if (type1 == integer_type_node)
return unsigned_type_node;
if (type1 == short_integer_type_node)
return short_unsigned_type_node;
if (type1 == long_integer_type_node)
return long_unsigned_type_node;
if (type1 == long_long_integer_type_node)
return long_long_unsigned_type_node;
if (type1 == widest_integer_literal_type_node)
return widest_unsigned_literal_type_node;
if (type1 == intTI_type_node)
return unsigned_intTI_type_node;
if (type1 == intDI_type_node)
return unsigned_intDI_type_node;
if (type1 == intSI_type_node)
return unsigned_intSI_type_node;
if (type1 == intHI_type_node)
return unsigned_intHI_type_node;
if (type1 == intQI_type_node)
return unsigned_intQI_type_node;
return c_common_signed_or_unsigned_type (1, type);
/* Return a signed type the same as TYPE in other respects. */
c_common_signed_type (type)
tree type;
tree type1 = TYPE_MAIN_VARIANT (type);
if (type1 == unsigned_char_type_node || type1 == char_type_node)
return signed_char_type_node;
if (type1 == unsigned_type_node)
return integer_type_node;
if (type1 == short_unsigned_type_node)
return short_integer_type_node;
if (type1 == long_unsigned_type_node)
return long_integer_type_node;
if (type1 == long_long_unsigned_type_node)
return long_long_integer_type_node;
if (type1 == widest_unsigned_literal_type_node)
return widest_integer_literal_type_node;
if (type1 == unsigned_intTI_type_node)
return intTI_type_node;
if (type1 == unsigned_intDI_type_node)
return intDI_type_node;
if (type1 == unsigned_intSI_type_node)
return intSI_type_node;
if (type1 == unsigned_intHI_type_node)
return intHI_type_node;
if (type1 == unsigned_intQI_type_node)
return intQI_type_node;
return c_common_signed_or_unsigned_type (0, type);
/* Return a type the same as TYPE except unsigned or
signed according to UNSIGNEDP. */
c_common_signed_or_unsigned_type (unsignedp, type)
int unsignedp;
tree type;
if (! INTEGRAL_TYPE_P (type)
|| TREE_UNSIGNED (type) == unsignedp)
return type;
if (TYPE_PRECISION (type) == TYPE_PRECISION (signed_char_type_node))
return unsignedp ? unsigned_char_type_node : signed_char_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
return unsignedp ? unsigned_type_node : integer_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (short_integer_type_node))
return unsignedp ? short_unsigned_type_node : short_integer_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (long_integer_type_node))
return unsignedp ? long_unsigned_type_node : long_integer_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (long_long_integer_type_node))
return (unsignedp ? long_long_unsigned_type_node
: long_long_integer_type_node);
if (TYPE_PRECISION (type) == TYPE_PRECISION (widest_integer_literal_type_node))
return (unsignedp ? widest_unsigned_literal_type_node
: widest_integer_literal_type_node);
if (TYPE_PRECISION (type) == TYPE_PRECISION (intTI_type_node))
return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (intDI_type_node))
return unsignedp ? unsigned_intDI_type_node : intDI_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (intSI_type_node))
return unsignedp ? unsigned_intSI_type_node : intSI_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (intHI_type_node))
return unsignedp ? unsigned_intHI_type_node : intHI_type_node;
if (TYPE_PRECISION (type) == TYPE_PRECISION (intQI_type_node))
return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
return type;
/* Return the minimum number of bits needed to represent VALUE in a
signed or unsigned type, UNSIGNEDP says which. */
unsigned int
min_precision (value, unsignedp)
tree value;
int unsignedp;
int log;
/* If the value is negative, compute its negative minus 1. The latter
adjustment is because the absolute value of the largest negative value
is one larger than the largest positive value. This is equivalent to
a bit-wise negation, so use that operation instead. */
if (tree_int_cst_sgn (value) < 0)
value = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (value), value));
/* Return the number of bits needed, taking into account the fact
that we need one more bit for a signed than unsigned type. */
if (integer_zerop (value))
log = 0;
log = tree_floor_log2 (value);
return log + 1 + ! unsignedp;
/* Print an error message for invalid operands to arith operation
CODE. NOP_EXPR is used as a special case (see
c_common_truthvalue_conversion). */
binary_op_error (code)
enum tree_code code;
const char *opname;
switch (code)
case NOP_EXPR:
error ("invalid truth-value expression");
opname = "+"; break;
opname = "-"; break;
opname = "*"; break;
case MAX_EXPR:
opname = "max"; break;
case MIN_EXPR:
opname = "min"; break;
case EQ_EXPR:
opname = "=="; break;
case NE_EXPR:
opname = "!="; break;
case LE_EXPR:
opname = "<="; break;
case GE_EXPR:
opname = ">="; break;
case LT_EXPR:
opname = "<"; break;
case GT_EXPR:
opname = ">"; break;
opname = "<<"; break;
opname = ">>"; break;
opname = "%"; break;
opname = "/"; break;
opname = "&"; break;
opname = "|"; break;
opname = "&&"; break;
opname = "||"; break;
opname = "^"; break;
opname = "rotate"; break;
opname = "unknown"; break;
error ("invalid operands to binary %s", opname);
/* Subroutine of build_binary_op, used for comparison operations.
See if the operands have both been converted from subword integer types
and, if so, perhaps change them both back to their original type.
This function is also responsible for converting the two operands
to the proper common type for comparison.
The arguments of this function are all pointers to local variables
of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
If this function returns nonzero, it means that the comparison has
a constant value. What this function returns is an expression for
that value. */
shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr)
tree *op0_ptr, *op1_ptr;
tree *restype_ptr;
enum tree_code *rescode_ptr;
tree type;
tree op0 = *op0_ptr;
tree op1 = *op1_ptr;
int unsignedp0, unsignedp1;
int real1, real2;
tree primop0, primop1;
enum tree_code code = *rescode_ptr;
/* Throw away any conversions to wider types
already present in the operands. */
primop0 = get_narrower (op0, &unsignedp0);
primop1 = get_narrower (op1, &unsignedp1);
/* Handle the case that OP0 does not *contain* a conversion
but it *requires* conversion to FINAL_TYPE. */
if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
unsignedp0 = TREE_UNSIGNED (TREE_TYPE (op0));
if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
unsignedp1 = TREE_UNSIGNED (TREE_TYPE (op1));
/* If one of the operands must be floated, we cannot optimize. */
real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
/* If first arg is constant, swap the args (changing operation
so value is preserved), for canonicalization. Don't do this if
the second arg is 0. */
if (TREE_CONSTANT (primop0)
&& ! integer_zerop (primop1) && ! real_zerop (primop1))
tree tem = primop0;
int temi = unsignedp0;
primop0 = primop1;
primop1 = tem;
tem = op0;
op0 = op1;
op1 = tem;
*op0_ptr = op0;
*op1_ptr = op1;
unsignedp0 = unsignedp1;
unsignedp1 = temi;
temi = real1;
real1 = real2;
real2 = temi;
switch (code)
case LT_EXPR:
code = GT_EXPR;
case GT_EXPR:
code = LT_EXPR;
case LE_EXPR:
code = GE_EXPR;
case GE_EXPR:
code = LE_EXPR;
*rescode_ptr = code;
/* If comparing an integer against a constant more bits wide,
maybe we can deduce a value of 1 or 0 independent of the data.
Or else truncate the constant now
rather than extend the variable at run time.
This is only interesting if the constant is the wider arg.
Also, it is not safe if the constant is unsigned and the
variable arg is signed, since in this case the variable
would be sign-extended and then regarded as unsigned.
Our technique fails in this case because the lowest/highest
possible unsigned results don't follow naturally from the
lowest/highest possible values of the variable operand.
For just EQ_EXPR and NE_EXPR there is another technique that
could be used: see if the constant can be faithfully represented
in the other operand's type, by truncating it and reextending it
and see if that preserves the constant's value. */
if (!real1 && !real2
&& TREE_CODE (primop1) == INTEGER_CST
&& TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
int min_gt, max_gt, min_lt, max_lt;
tree maxval, minval;
/* 1 if comparison is nominally unsigned. */
int unsignedp = TREE_UNSIGNED (*restype_ptr);
tree val;
type = c_common_signed_or_unsigned_type (unsignedp0,
TREE_TYPE (primop0));
/* If TYPE is an enumeration, then we need to get its min/max
values from it's underlying integral type, not the enumerated
type itself. */
type = c_common_type_for_size (TYPE_PRECISION (type), unsignedp0);
maxval = TYPE_MAX_VALUE (type);
minval = TYPE_MIN_VALUE (type);
if (unsignedp && !unsignedp0)
*restype_ptr = c_common_signed_type (*restype_ptr);
if (TREE_TYPE (primop1) != *restype_ptr)
primop1 = convert (*restype_ptr, primop1);
if (type != *restype_ptr)
minval = convert (*restype_ptr, minval);
maxval = convert (*restype_ptr, maxval);
if (unsignedp && unsignedp0)
min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
min_gt = INT_CST_LT (primop1, minval);
max_gt = INT_CST_LT (primop1, maxval);
min_lt = INT_CST_LT (minval, primop1);
max_lt = INT_CST_LT (maxval, primop1);
val = 0;
/* This used to be a switch, but Genix compiler can't handle that. */
if (code == NE_EXPR)
if (max_lt || min_gt)
val = boolean_true_node;
else if (code == EQ_EXPR)
if (max_lt || min_gt)
val = boolean_false_node;
else if (code == LT_EXPR)
if (max_lt)
val = boolean_true_node;
if (!min_lt)
val = boolean_false_node;
else if (code == GT_EXPR)
if (min_gt)
val = boolean_true_node;
if (!max_gt)
val = boolean_false_node;
else if (code == LE_EXPR)
if (!max_gt)
val = boolean_true_node;
if (min_gt)
val = boolean_false_node;
else if (code == GE_EXPR)
if (!min_lt)
val = boolean_true_node;
if (max_lt)
val = boolean_false_node;
/* If primop0 was sign-extended and unsigned comparison specd,
we did a signed comparison above using the signed type bounds.
But the comparison we output must be unsigned.
Also, for inequalities, VAL is no good; but if the signed
comparison had *any* fixed result, it follows that the
unsigned comparison just tests the sign in reverse
(positive values are LE, negative ones GE).
So we can generate an unsigned comparison
against an extreme value of the signed type. */
if (unsignedp && !unsignedp0)
if (val != 0)
switch (code)
case LT_EXPR:
case GE_EXPR:
primop1 = TYPE_MIN_VALUE (type);
val = 0;
case LE_EXPR:
case GT_EXPR:
primop1 = TYPE_MAX_VALUE (type);
val = 0;
type = c_common_unsigned_type (type);
if (TREE_CODE (primop0) != INTEGER_CST)
if (val == boolean_false_node)
warning ("comparison is always false due to limited range of data type");
if (val == boolean_true_node)
warning ("comparison is always true due to limited range of data type");
if (val != 0)
/* Don't forget to evaluate PRIMOP0 if it has side effects. */
if (TREE_SIDE_EFFECTS (primop0))
return build (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
return val;
/* Value is not predetermined, but do the comparison
in the type of the operand that is not constant.
TYPE is already properly set. */
else if (real1 && real2
type = TREE_TYPE (primop0);
/* If args' natural types are both narrower than nominal type
and both extend in the same manner, compare them
in the type of the wider arg.
Otherwise must actually extend both to the nominal
common type lest different ways of extending
alter the result.
(eg, (short)-1 == (unsigned short)-1 should be 0.) */
else if (unsignedp0 == unsignedp1 && real1 == real2
&& TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
&& TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
type = c_common_signed_or_unsigned_type (unsignedp0
|| TREE_UNSIGNED (*restype_ptr),
/* Make sure shorter operand is extended the right way
to match the longer operand. */
= convert (c_common_signed_or_unsigned_type (unsignedp0,
TREE_TYPE (primop0)),
= convert (c_common_signed_or_unsigned_type (unsignedp1,
TREE_TYPE (primop1)),
/* Here we must do the comparison on the nominal type
using the args exactly as we received them. */
type = *restype_ptr;
primop0 = op0;
primop1 = op1;
if (!real1 && !real2 && integer_zerop (primop1)
&& TREE_UNSIGNED (*restype_ptr))
tree value = 0;
switch (code)
case GE_EXPR:
/* All unsigned values are >= 0, so we warn if extra warnings
are requested. However, if OP0 is a constant that is
>= 0, the signedness of the comparison isn't an issue,
so suppress the warning. */
if (extra_warnings && !in_system_header
&& ! (TREE_CODE (primop0) == INTEGER_CST
&& ! TREE_OVERFLOW (convert (c_common_signed_type (type),
warning ("comparison of unsigned expression >= 0 is always true");
value = boolean_true_node;
case LT_EXPR:
if (extra_warnings && !in_system_header
&& ! (TREE_CODE (primop0) == INTEGER_CST
&& ! TREE_OVERFLOW (convert (c_common_signed_type (type),
warning ("comparison of unsigned expression < 0 is always false");
value = boolean_false_node;
if (value != 0)
/* Don't forget to evaluate PRIMOP0 if it has side effects. */
if (TREE_SIDE_EFFECTS (primop0))
return build (COMPOUND_EXPR, TREE_TYPE (value),
primop0, value);
return value;
*op0_ptr = convert (type, primop0);
*op1_ptr = convert (type, primop1);
*restype_ptr = boolean_type_node;
return 0;
/* Return a tree for the sum or difference (RESULTCODE says which)
of pointer PTROP and integer INTOP. */
pointer_int_sum (resultcode, ptrop, intop)
enum tree_code resultcode;
tree ptrop, intop;
tree size_exp;
tree result;
tree folded;
/* The result is a pointer of the same type that is being added. */
tree result_type = TREE_TYPE (ptrop);
if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
if (pedantic || warn_pointer_arith)
pedwarn ("pointer of type `void *' used in arithmetic");
size_exp = integer_one_node;
else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE)
if (pedantic || warn_pointer_arith)
pedwarn ("pointer to a function used in arithmetic");
size_exp = integer_one_node;
else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE)
if (pedantic || warn_pointer_arith)
pedwarn ("pointer to member function used in arithmetic");
size_exp = integer_one_node;
else if (TREE_CODE (TREE_TYPE (result_type)) == OFFSET_TYPE)
if (pedantic || warn_pointer_arith)
pedwarn ("pointer to a member used in arithmetic");
size_exp = integer_one_node;
size_exp = size_in_bytes (TREE_TYPE (result_type));
/* If what we are about to multiply by the size of the elements
contains a constant term, apply distributive law
and multiply that constant term separately.
This helps produce common subexpressions. */
if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
&& ! TREE_CONSTANT (intop)
&& TREE_CONSTANT (size_exp)
/* If the constant comes from pointer subtraction,
skip this optimization--it would cause an error. */
/* If the constant is unsigned, and smaller than the pointer size,
then we must skip this optimization. This is because it could cause
an overflow error if the constant is negative but INTOP is not. */
enum tree_code subcode = resultcode;
tree int_type = TREE_TYPE (intop);
if (TREE_CODE (intop) == MINUS_EXPR)
subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
/* Convert both subexpression types to the type of intop,
because weird cases involving pointer arithmetic
can result in a sum or difference with different type args. */
ptrop = build_binary_op (subcode, ptrop,
convert (int_type, TREE_OPERAND (intop, 1)), 1);
intop = convert (int_type, TREE_OPERAND (intop, 0));
/* Convert the integer argument to a type the same size as sizetype
so the multiply won't overflow spuriously. */
|| TREE_UNSIGNED (TREE_TYPE (intop)) != TREE_UNSIGNED (sizetype))
intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype),
TREE_UNSIGNED (sizetype)), intop);
/* Replace the integer argument with a suitable product by the object size.
Do this multiplication as signed, then convert to the appropriate
pointer type (actually unsigned integral). */
intop = convert (result_type,
build_binary_op (MULT_EXPR, intop,
convert (TREE_TYPE (intop), size_exp), 1));
/* Create the sum or difference. */
result = build (resultcode, result_type, ptrop, intop);
folded = fold (result);
if (folded == result)
return folded;
/* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
or validate its data type for an `if' or `while' statement or ?..: exp.
This preparation consists of taking the ordinary
representation of an expression expr and producing a valid tree
boolean expression describing whether expr is nonzero. We could
simply always do build_binary_op (NE_EXPR, expr, boolean_false_node, 1),
but we optimize comparisons, &&, ||, and !.
The resulting type should always be `boolean_type_node'. */
c_common_truthvalue_conversion (expr)
tree expr;
if (TREE_CODE (expr) == ERROR_MARK)
return expr;
#if 0 /* This appears to be wrong for C++. */
/* These really should return error_mark_node after 2.4 is stable.
But not all callers handle ERROR_MARK properly. */
switch (TREE_CODE (TREE_TYPE (expr)))
error ("struct type value used where scalar is required");
return boolean_false_node;
error ("union type value used where scalar is required");
return boolean_false_node;
error ("array type value used where scalar is required");
return boolean_false_node;
#endif /* 0 */
switch (TREE_CODE (expr))
case EQ_EXPR:
case NE_EXPR: case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
TREE_TYPE (expr) = boolean_type_node;
return expr;
return expr;
return integer_zerop (expr) ? boolean_false_node : boolean_true_node;
case REAL_CST:
return real_zerop (expr) ? boolean_false_node : boolean_true_node;
/* If we are taking the address of an external decl, it might be zero
if it is weak, so we cannot optimize. */
if (DECL_P (TREE_OPERAND (expr, 0))
return build (COMPOUND_EXPR, boolean_type_node,
TREE_OPERAND (expr, 0), boolean_true_node);
return boolean_true_node;
return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)),
c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
case ABS_EXPR:
case FFS_EXPR:
/* These don't change whether an object is nonzero or zero. */
return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
/* These don't change whether an object is zero or nonzero, but
we can't ignore them if their second arg has side-effects. */
return build (COMPOUND_EXPR, boolean_type_node, TREE_OPERAND (expr, 1),
c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)));
return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
/* Distribute the conversion into the arms of a COND_EXPR. */
return fold (build (COND_EXPR, boolean_type_node, TREE_OPERAND (expr, 0),
c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)),
c_common_truthvalue_conversion (TREE_OPERAND (expr, 2))));
/* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
since that affects how `default_conversion' will behave. */
/* fall through... */
case NOP_EXPR:
/* If this is widening the argument, we can ignore it. */
return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0));
/* Perhaps reduce (x - y) != 0 to (x != y). The expressions
aren't guaranteed to the be same for modes that can represent
infinity, since if x and y are both +infinity, or both
-infinity, then x - y is not a number.
Note that this transformation is safe when x or y is NaN.
(x - y) is then NaN, and both (x - y) != 0 and x != y will
be false. */
/* fall through... */
/* This and MINUS_EXPR can be changed into a comparison of the
two objects. */
if (TREE_TYPE (TREE_OPERAND (expr, 0))
== TREE_TYPE (TREE_OPERAND (expr, 1)))
return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
TREE_OPERAND (expr, 1), 1);
return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
fold (build1 (NOP_EXPR,
TREE_OPERAND (expr, 1))), 1);
if (integer_onep (TREE_OPERAND (expr, 1))
&& TREE_TYPE (expr) != boolean_type_node)
/* Using convert here would cause infinite recursion. */
return build1 (NOP_EXPR, boolean_type_node, expr);
if (warn_parentheses && C_EXP_ORIGINAL_CODE (expr) == MODIFY_EXPR)
warning ("suggest parentheses around assignment used as truth value");
tree t = save_expr (expr);
return (build_binary_op
c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)),
c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)),
return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
static tree builtin_function_2 PARAMS ((const char *, const char *, tree, tree,
int, enum built_in_class, int, int,
/* Make a variant type in the proper way for C/C++, propagating qualifiers
down to the element type of an array. */
c_build_qualified_type (type, type_quals)
tree type;
int type_quals;
/* A restrict-qualified pointer type must be a pointer to object or
incomplete type. Note that the use of POINTER_TYPE_P also allows
REFERENCE_TYPEs, which is appropriate for C++. Unfortunately,
the C++ front-end also use POINTER_TYPE for pointer-to-member
values, so even though it should be illegal to use `restrict'
with such an entity we don't flag that here. Thus, special case
code for that case is required in the C++ front-end. */
if ((type_quals & TYPE_QUAL_RESTRICT)
&& (!POINTER_TYPE_P (type)
error ("invalid use of `restrict'");
type_quals &= ~TYPE_QUAL_RESTRICT;
if (TREE_CODE (type) == ARRAY_TYPE)
return build_array_type (c_build_qualified_type (TREE_TYPE (type),
TYPE_DOMAIN (type));
return build_qualified_type (type, type_quals);
/* Apply the TYPE_QUALS to the new DECL. */
c_apply_type_quals_to_decl (type_quals, decl)
int type_quals;
tree decl;
if ((type_quals & TYPE_QUAL_CONST)
|| (TREE_TYPE (decl)
TREE_READONLY (decl) = 1;
if (type_quals & TYPE_QUAL_VOLATILE)
if (type_quals & TYPE_QUAL_RESTRICT)
if (!TREE_TYPE (decl)
error ("invalid use of `restrict'");
else if (flag_strict_aliasing)
/* Indicate we need to make a unique alias set for this pointer.
We can't do it here because it might be pointing to an
incomplete type. */
/* Return the typed-based alias set for T, which may be an expression
or a type. Return -1 if we don't do anything special. */
c_common_get_alias_set (t)
tree t;
tree u;
/* Permit type-punning when accessing a union, provided the access
is directly through the union. For example, this code does not
permit taking the address of a union member and then storing
through it. Even the type-punning allowed here is a GCC
extension, albeit a common and useful one; the C standard says
that such accesses have implementation-defined behavior. */
for (u = t;
u = TREE_OPERAND (u, 0))
return 0;
/* That's all the expressions we handle specially. */
if (! TYPE_P (t))
return -1;
/* The C standard guarantess that any object may be accessed via an
lvalue that has character type. */
if (t == char_type_node
|| t == signed_char_type_node
|| t == unsigned_char_type_node)
return 0;
/* If it has the may_alias attribute, it can alias anything. */
if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
return 0;
/* The C standard specifically allows aliasing between signed and
unsigned variants of the same type. We treat the signed
variant as canonical. */
tree t1 = c_common_signed_type (t);
/* t1 == t can happen for boolean nodes which are always unsigned. */
if (t1 != t)
return get_alias_set (t1);
else if (POINTER_TYPE_P (t))
tree t1;
/* Unfortunately, there is no canonical form of a pointer type.
In particular, if we have `typedef int I', then `int *', and
`I *' are different types. So, we have to pick a canonical
representative. We do this below.
Technically, this approach is actually more conservative that
it needs to be. In particular, `const int *' and `int *'
should be in different alias sets, according to the C and C++
standard, since their types are not the same, and so,
technically, an `int **' and `const int **' cannot point at
the same thing.
But, the standard is wrong. In particular, this code is
legal C++:
int *ip;
int **ipp = &ip;
const int* const* cipp = &ipp;
And, it doesn't make sense for that to be legal unless you
can dereference IPP and CIPP. So, we ignore cv-qualifiers on
the pointed-to types. This issue has been reported to the
C++ committee. */
t1 = build_type_no_quals (t);
if (t1 != t)
return get_alias_set (t1);
return -1;
/* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the
second parameter indicates which OPERATOR is being applied. The COMPLAIN
flag controls whether we should diagnose possibly ill-formed
constructs or not. */
c_sizeof_or_alignof_type (type, op, complain)
tree type;
enum tree_code op;
int complain;
const char *op_name;
tree value = NULL;
enum tree_code type_code = TREE_CODE (type);
my_friendly_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR, 20020720);
op_name = op == SIZEOF_EXPR ? "sizeof" : "__alignof__";
if (type_code == FUNCTION_TYPE)
if (op == SIZEOF_EXPR)
if (complain && (pedantic || warn_pointer_arith))
pedwarn ("invalid application of `sizeof' to a function type");
value = size_one_node;
else if (type_code == VOID_TYPE || type_code == ERROR_MARK)
if (type_code == VOID_TYPE
&& complain && (pedantic || warn_pointer_arith))
pedwarn ("invalid application of `%s' to a void type", op_name);
value = size_one_node;
else if (!COMPLETE_TYPE_P (type))
if (complain)
error ("invalid application of `%s' to an incomplete type", op_name);
value = size_zero_node;
if (op == SIZEOF_EXPR)
/* Convert in case a char is more than one unit. */
value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
size_int (TYPE_PRECISION (char_type_node)
value = size_int (TYPE_ALIGN (type) / BITS_PER_UNIT);
/* VALUE will have an integer type with TYPE_IS_SIZETYPE set.
TYPE_IS_SIZETYPE means that certain things (like overflow) will
never happen. However, this node should really have type
`size_t', which is just a typedef for an ordinary integer type. */
value = fold (build1 (NOP_EXPR, size_type_node, value));
my_friendly_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value)), 20001021);
return value;
/* Implement the __alignof keyword: Return the minimum required
alignment of EXPR, measured in bytes. For VAR_DECL's and
FIELD_DECL's return DECL_ALIGN (which can be set from an
"aligned" __attribute__ specification). */
c_alignof_expr (expr)
tree expr;
tree t;
if (TREE_CODE (expr) == VAR_DECL)
t = size_int (DECL_ALIGN (expr) / BITS_PER_UNIT);
else if (TREE_CODE (expr) == COMPONENT_REF
error ("`__alignof' applied to a bit-field");
t = size_one_node;
else if (TREE_CODE (expr) == COMPONENT_REF
t = size_int (DECL_ALIGN (TREE_OPERAND (expr, 1)) / BITS_PER_UNIT);
else if (TREE_CODE (expr) == INDIRECT_REF)
tree t = TREE_OPERAND (expr, 0);
tree best = t;
int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
while (TREE_CODE (t) == NOP_EXPR
int thisalign;
t = TREE_OPERAND (t, 0);
thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t)));
if (thisalign > bestalign)
best = t, bestalign = thisalign;
return c_alignof (TREE_TYPE (TREE_TYPE (best)));
return c_alignof (TREE_TYPE (expr));
return fold (build1 (NOP_EXPR, size_type_node, t));
/* Handle C and C++ default attributes. */
enum built_in_attribute
#define DEF_FN_ATTR(NAME, ATTRS, PREDICATE) /* No entry needed in enum. */
#include "builtin-attrs.def"
#undef DEF_FN_ATTR
static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
static bool c_attrs_initialized = false;
static void c_init_attributes PARAMS ((void));
/* Build tree nodes and builtin functions common to both C and C++ language
frontends. */
c_common_nodes_and_builtins ()
enum builtin_type
#include "builtin-types.def"
typedef enum builtin_type builtin_type;
tree builtin_types[(int) BT_LAST];
int wchar_type_size;
tree array_domain_type;
tree va_list_ref_type_node;
tree va_list_arg_type_node;
/* Define `int' and `char' first so that dbx will output them first. */
record_builtin_type (RID_INT, NULL, integer_type_node);
record_builtin_type (RID_CHAR, "char", char_type_node);
/* `signed' is the same as `int'. FIXME: the declarations of "signed",
"unsigned long", "long long unsigned" and "unsigned short" were in C++
but not C. Are the conditionals here needed? */
if (c_language == clk_cplusplus)
record_builtin_type (RID_SIGNED, NULL, integer_type_node);
record_builtin_type (RID_LONG, "long int", long_integer_type_node);
record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node);
record_builtin_type (RID_MAX, "long unsigned int",
if (c_language == clk_cplusplus)
record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node);
record_builtin_type (RID_MAX, "long long int",
record_builtin_type (RID_MAX, "long long unsigned int",
if (c_language == clk_cplusplus)
record_builtin_type (RID_MAX, "long long unsigned",
record_builtin_type (RID_SHORT, "short int", short_integer_type_node);
record_builtin_type (RID_MAX, "short unsigned int",
if (c_language == clk_cplusplus)
record_builtin_type (RID_MAX, "unsigned short",
/* Define both `signed char' and `unsigned char'. */
record_builtin_type (RID_MAX, "signed char", signed_char_type_node);
record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node);
/* These are types that c_common_type_for_size and
c_common_type_for_mode use. */
(*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
(*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
(*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
(*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL, NULL_TREE,
(*lang_hooks.decls.pushdecl) (build_decl (TYPE_DECL,
get_identifier ("__int128_t"),