blob: b556d0825f1fd7e4a25b262165e15e03746f249f [file] [log] [blame]
/* Process declarations and variables for C compiler.
Copyright (C) 1988, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC 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 version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* Process declarations and symbol lookup for C front end.
Also constructs types; the standard scalar types at initialization,
and structure, union, array and enum types when they are declared. */
/* ??? not all decl nodes are given the most useful possible
line numbers. For example, the CONST_DECLs for enum values. */
#include "config.h"
#include "tree.h"
#include "flags.h"
#include "output.h"
#include "c-tree.h"
#include "c-lex.h"
#include <stdio.h>
/* In grokdeclarator, distinguish syntactic contexts of declarators. */
enum decl_context
{ NORMAL, /* Ordinary declaration */
FUNCDEF, /* Function definition */
PARM, /* Declaration of parm before function body */
FIELD, /* Declaration inside struct or union */
BITFIELD, /* Likewise but with specified width */
TYPENAME}; /* Typename (inside cast or sizeof) */
/* 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"
#define PTRDIFF_TYPE "long int"
#ifndef WCHAR_TYPE
#define WCHAR_TYPE "int"
/* a node which has tree code ERROR_MARK, and whose type is itself.
All erroneous expressions are replaced with this node. All functions
that accept nodes as arguments should avoid generating error messages
if this node is one of the arguments, since it is undesirable to get
multiple error messages from one error in the input. */
tree error_mark_node;
/* INTEGER_TYPE and REAL_TYPE nodes for the standard data types */
tree short_integer_type_node;
tree integer_type_node;
tree long_integer_type_node;
tree long_long_integer_type_node;
tree short_unsigned_type_node;
tree 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 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 unsigned_intQI_type_node;
tree unsigned_intHI_type_node;
tree unsigned_intSI_type_node;
tree unsigned_intDI_type_node;
/* a VOID_TYPE node. */
tree void_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;
/* function types `double (double)' and `double (double, double)', etc. */
tree double_ftype_double, double_ftype_double_double;
tree int_ftype_int, long_ftype_long;
tree float_ftype_float;
tree ldouble_ftype_ldouble;
/* Function type `void (void *, void *, int)' and similar ones */
tree void_ftype_ptr_ptr_int, int_ftype_ptr_ptr_int, void_ftype_ptr_int_int;
/* Function type `char *(char *, char *)' and similar ones */
tree string_ftype_ptr_ptr, int_ftype_string_string;
/* Function type `int (const void *, const void *, size_t)' */
tree int_ftype_cptr_cptr_sizet;
/* Two expressions that are constants with value zero.
The first is of type `int', the second of type `void *'. */
tree integer_zero_node;
tree null_pointer_node;
/* A node for the integer constant 1. */
tree integer_one_node;
/* Nonzero if we have seen an invalid cross reference
to a struct, union, or enum, but not yet printed the message. */
tree pending_invalid_xref;
/* File and line to appear in the eventual error message. */
char *pending_invalid_xref_file;
int pending_invalid_xref_line;
/* While defining an enum type, this is 1 plus the last enumerator
constant value. Note that will do not have to save this or `enum_overflow'
around nested function definition since such a definition could only
occur in an enum value expression and we don't use these variables in
that case. */
static tree enum_next_value;
/* Nonzero means that there was overflow computing enum_next_value. */
static int enum_overflow;
/* Parsing a function declarator leaves a list of parameter names
or a chain or parameter decls here. */
static tree last_function_parms;
/* Parsing a function declarator leaves here a chain of structure
and enum types declared in the parmlist. */
static tree last_function_parm_tags;
/* After parsing the declarator that starts a function definition,
`start_function' puts here the list of parameter names or chain of decls.
`store_parm_decls' finds it here. */
static tree current_function_parms;
/* Similar, for last_function_parm_tags. */
static tree current_function_parm_tags;
/* Similar, for the file and line that the prototype came from if this is
an old-style definition. */
static char *current_function_prototype_file;
static int current_function_prototype_line;
/* A list (chain of TREE_LIST nodes) of all LABEL_DECLs in the function
that have names. Here so we can clear out their names' definitions
at the end of the function. */
static tree named_labels;
/* A list of LABEL_DECLs from outer contexts that are currently shadowed. */
static tree shadowed_labels;
/* Nonzero when store_parm_decls is called indicates a varargs function.
Value not meaningful after store_parm_decls. */
static int c_function_varargs;
/* The FUNCTION_DECL for the function currently being compiled,
or 0 if between functions. */
tree current_function_decl;
/* Set to 0 at beginning of a function definition, set to 1 if
a return statement that specifies a return value is seen. */
int current_function_returns_value;
/* Set to 0 at beginning of a function definition, set to 1 if
a return statement with no argument is seen. */
int current_function_returns_null;
/* Set to nonzero by `grokdeclarator' for a function
whose return type is defaulted, if warnings for this are desired. */
static int warn_about_return_type;
/* Nonzero when starting a function declared `extern inline'. */
static int current_extern_inline;
/* For each binding contour we allocate a binding_level structure
* which records the names defined in that contour.
* Contours include:
* 0) the global one
* 1) one for each function definition,
* where internal declarations of the parameters appear.
* 2) one for each compound statement,
* to record its declarations.
* The current meaning of a name can be found by searching the levels from
* the current one out to the global one.
/* Note that the information in the `names' component of the global contour
is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers. */
struct binding_level
/* A chain of _DECL nodes for all variables, constants, functions,
and typedef types. These are in the reverse of the order supplied.
tree names;
/* A list of structure, union and enum definitions,
* for looking up tag names.
* It is a chain of TREE_LIST nodes, each of whose TREE_PURPOSE is a name,
* or ENUMERAL_TYPE node.
tree tags;
/* For each level, a list of shadowed outer-level local definitions
to be restored when this level is popped.
Each link is a TREE_LIST whose TREE_PURPOSE is an identifier and
whose TREE_VALUE is its old definition (a kind of ..._DECL node). */
tree shadowed;
/* For each level (except not the global one),
a chain of BLOCK nodes for all the levels
that were entered and exited one level down. */
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 which this one is contained in (inherits from). */
struct binding_level *level_chain;
/* Nonzero for the level that holds the parameters of a function. */
char parm_flag;
/* Nonzero if this level "doesn't exist" for tags. */
char tag_transparent;
/* Nonzero if sublevels of this level "don't exist" for tags.
This is set in the parm level of a function definition
while reading the function body, so that the outermost block
of the function body will be tag-transparent. */
char subblocks_tag_transparent;
/* Nonzero means make a BLOCK for this level regardless of all else. */
char keep;
/* Nonzero means make a BLOCK if this level has any subblocks. */
char keep_if_subblocks;
/* Number of decls in `names' that have incomplete
structure or union types. */
int n_incomplete;
/* A list of decls giving the (reversed) specified order of parms,
not including any forward-decls in the parmlist.
This is so we can put the parms in proper order for assign_parms. */
tree parm_order;
#define NULL_BINDING_LEVEL (struct binding_level *) NULL
/* The binding level currently in effect. */
static struct binding_level *current_binding_level;
/* A chain of binding_level structures awaiting reuse. */
static struct binding_level *free_binding_level;
/* The outermost binding level, for names of file scope.
This is created when the compiler is started and exists
through the entire run. */
static struct binding_level *global_binding_level;
/* Binding level structures are initialized by copying this one. */
static struct binding_level clear_binding_level
/* Nonzero means unconditionally make a BLOCK for the next level pushed. */
static int keep_next_level_flag;
/* Nonzero means make a BLOCK for the next level pushed
if it has subblocks. */
static int keep_next_if_subblocks;
/* The chain of outer levels of label scopes.
This uses the same data structure used for binding levels,
but it works differently: each link in the chain records
saved values of named_labels and shadowed_labels for
a label binding level outside the current one. */
static struct binding_level *label_level_chain;
/* Functions called automatically at the beginning and end of execution. */
tree static_ctors, static_dtors;
/* Forward declarations. */
static struct binding_level * make_binding_level PROTO((void));
static void clear_limbo_values PROTO((tree));
static int duplicate_decls PROTO((tree, tree, int));
static char *redeclaration_error_message PROTO((tree, tree));
static void storedecls PROTO((tree));
static void storetags PROTO((tree));
static tree lookup_tag PROTO((enum tree_code, tree,
struct binding_level *, int));
static tree lookup_tag_reverse PROTO((tree));
static tree grokdeclarator PROTO((tree, tree, enum decl_context,
static tree grokparms PROTO((tree, int));
static int field_decl_cmp PROTO((const GENERIC_PTR, const GENERIC_PTR));
static void layout_array_type PROTO((tree));
/* C-specific option variables. */
/* Nonzero means allow type mismatches in conditional expressions;
just make their values `void'. */
int flag_cond_mismatch;
/* Nonzero means give `double' the same size as `float'. */
int flag_short_double;
/* Nonzero means don't recognize the keyword `asm'. */
int flag_no_asm;
/* Nonzero means don't recognize any 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 do some things the same way PCC does. */
int flag_traditional;
/* Nonzero means that we have builtin functions, and main is an int */
int flag_hosted = 1;
/* Nonzero means to allow single precision math even if we're generally
being traditional. */
int flag_allow_single_precision = 0;
/* Nonzero means to treat bitfields as signed unless they say `unsigned'. */
int flag_signed_bitfields = 1;
int explicit_flag_signed_bitfields = 0;
/* Nonzero means handle `#ident' directives. 0 means ignore them. */
int flag_no_ident = 0;
/* Nonzero means warn about implicit declarations. */
int warn_implicit;
/* Nonzero means give string constants the type `const char *'
to get extra warnings from them. These warnings will be too numerous
to be useful, except in thoroughly ANSIfied programs. */
int warn_write_strings;
/* Nonzero means warn about pointer casts that can drop a type qualifier
from the pointer target type. */
int warn_cast_qual;
/* 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 about sizeof(function) or addition/subtraction
of function pointers. */
int warn_pointer_arith;
/* 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 prototype decl. */
int warn_missing_prototypes;
/* Nonzero means warn for any global function def
without separate previous decl. */
int warn_missing_declarations;
/* Nonzero means warn about multiple (redundant) decls for the same single
variable or function. */
int warn_redundant_decls = 0;
/* Nonzero means warn about extern declarations of objects not at
file-scope level and about *all* declarations of functions (whether
extern 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 = 0;
/* Warn about *printf or *scanf format/argument anomalies. */
int warn_format;
/* Warn about a subscript that has type char. */
int warn_char_subscripts = 0;
/* Warn if a type conversion is done that might have confusing results. */
int warn_conversion;
/* Warn if adding () is suggested. */
int warn_parentheses;
/* Warn if initializer is not completely bracketed. */
int warn_missing_braces;
/* Warn if main is suspicious. */
int warn_main;
/* Warn about comparison of signed and unsigned values. */
int warn_sign_compare;
/* Nonzero means `$' can be in an identifier. */
int dollars_in_ident = DOLLARS_IN_IDENTIFIERS;
/* Decode the string P as a language-specific option for C.
Return 1 if it is recognized (and handle it);
return 0 if not recognized. */
c_decode_option (p)
char *p;
if (!strcmp (p, "-ftraditional") || !strcmp (p, "-traditional"))
flag_traditional = 1;
flag_writable_strings = 1;
else if (!strcmp (p, "-fallow-single-precision"))
flag_allow_single_precision = 1;
else if (!strcmp (p, "-fhosted") || !strcmp (p, "-fno-freestanding"))
flag_hosted = 1;
flag_no_builtin = 0;
else if (!strcmp (p, "-ffreestanding") || !strcmp (p, "-fno-hosted"))
flag_hosted = 0;
flag_no_builtin = 1;
/* warn_main will be 2 if set by -Wall, 1 if set by -Wmain */
if (warn_main == 2)
warn_main = 0;
else if (!strcmp (p, "-fnotraditional") || !strcmp (p, "-fno-traditional"))
flag_traditional = 0;
flag_writable_strings = 0;
else if (!strcmp (p, "-fdollars-in-identifiers"))
dollars_in_ident = 1;
else if (!strcmp (p, "-fno-dollars-in-identifiers"))
dollars_in_ident = 0;
else if (!strcmp (p, "-fsigned-char"))
flag_signed_char = 1;
else if (!strcmp (p, "-funsigned-char"))
flag_signed_char = 0;
else if (!strcmp (p, "-fno-signed-char"))
flag_signed_char = 0;
else if (!strcmp (p, "-fno-unsigned-char"))
flag_signed_char = 1;
else if (!strcmp (p, "-fsigned-bitfields")
|| !strcmp (p, "-fno-unsigned-bitfields"))
flag_signed_bitfields = 1;
explicit_flag_signed_bitfields = 1;
else if (!strcmp (p, "-funsigned-bitfields")
|| !strcmp (p, "-fno-signed-bitfields"))
flag_signed_bitfields = 0;
explicit_flag_signed_bitfields = 1;
else if (!strcmp (p, "-fshort-enums"))
flag_short_enums = 1;
else if (!strcmp (p, "-fno-short-enums"))
flag_short_enums = 0;
else if (!strcmp (p, "-fcond-mismatch"))
flag_cond_mismatch = 1;
else if (!strcmp (p, "-fno-cond-mismatch"))
flag_cond_mismatch = 0;
else if (!strcmp (p, "-fshort-double"))
flag_short_double = 1;
else if (!strcmp (p, "-fno-short-double"))
flag_short_double = 0;
else if (!strcmp (p, "-fasm"))
flag_no_asm = 0;
else if (!strcmp (p, "-fno-asm"))
flag_no_asm = 1;
else if (!strcmp (p, "-fbuiltin"))
flag_no_builtin = 0;
else if (!strcmp (p, "-fno-builtin"))
flag_no_builtin = 1;
else if (!strcmp (p, "-fno-ident"))
flag_no_ident = 1;
else if (!strcmp (p, "-fident"))
flag_no_ident = 0;
else if (!strcmp (p, "-ansi"))
flag_no_asm = 1, flag_no_nonansi_builtin = 1;
else if (!strcmp (p, "-Wimplicit"))
warn_implicit = 1;
else if (!strcmp (p, "-Wno-implicit"))
warn_implicit = 0;
else if (!strcmp (p, "-Wwrite-strings"))
warn_write_strings = 1;
else if (!strcmp (p, "-Wno-write-strings"))
warn_write_strings = 0;
else if (!strcmp (p, "-Wcast-qual"))
warn_cast_qual = 1;
else if (!strcmp (p, "-Wno-cast-qual"))
warn_cast_qual = 0;
else if (!strcmp (p, "-Wbad-function-cast"))
warn_bad_function_cast = 1;
else if (!strcmp (p, "-Wno-bad-function-cast"))
warn_bad_function_cast = 0;
else if (!strcmp (p, "-Wpointer-arith"))
warn_pointer_arith = 1;
else if (!strcmp (p, "-Wno-pointer-arith"))
warn_pointer_arith = 0;
else if (!strcmp (p, "-Wstrict-prototypes"))
warn_strict_prototypes = 1;
else if (!strcmp (p, "-Wno-strict-prototypes"))
warn_strict_prototypes = 0;
else if (!strcmp (p, "-Wmissing-prototypes"))
warn_missing_prototypes = 1;
else if (!strcmp (p, "-Wno-missing-prototypes"))
warn_missing_prototypes = 0;
else if (!strcmp (p, "-Wmissing-declarations"))
warn_missing_declarations = 1;
else if (!strcmp (p, "-Wno-missing-declarations"))
warn_missing_declarations = 0;
else if (!strcmp (p, "-Wredundant-decls"))
warn_redundant_decls = 1;
else if (!strcmp (p, "-Wno-redundant-decls"))
warn_redundant_decls = 0;
else if (!strcmp (p, "-Wnested-externs"))
warn_nested_externs = 1;
else if (!strcmp (p, "-Wno-nested-externs"))
warn_nested_externs = 0;
else if (!strcmp (p, "-Wtraditional"))
warn_traditional = 1;
else if (!strcmp (p, "-Wno-traditional"))
warn_traditional = 0;
else if (!strcmp (p, "-Wformat"))
warn_format = 1;
else if (!strcmp (p, "-Wno-format"))
warn_format = 0;
else if (!strcmp (p, "-Wchar-subscripts"))
warn_char_subscripts = 1;
else if (!strcmp (p, "-Wno-char-subscripts"))
warn_char_subscripts = 0;
else if (!strcmp (p, "-Wconversion"))
warn_conversion = 1;
else if (!strcmp (p, "-Wno-conversion"))
warn_conversion = 0;
else if (!strcmp (p, "-Wparentheses"))
warn_parentheses = 1;
else if (!strcmp (p, "-Wno-parentheses"))
warn_parentheses = 0;
else if (!strcmp (p, "-Wreturn-type"))
warn_return_type = 1;
else if (!strcmp (p, "-Wno-return-type"))
warn_return_type = 0;
else if (!strcmp (p, "-Wcomment"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wno-comment"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wcomments"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wno-comments"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wtrigraphs"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wno-trigraphs"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wundef"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wno-undef"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wimport"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wno-import"))
; /* cpp handles this one. */
else if (!strcmp (p, "-Wmissing-braces"))
warn_missing_braces = 1;
else if (!strcmp (p, "-Wno-missing-braces"))
warn_missing_braces = 0;
else if (!strcmp (p, "-Wmain"))
warn_main = 1;
else if (!strcmp (p, "-Wno-main"))
warn_main = 0;
else if (!strcmp (p, "-Wsign-compare"))
warn_sign_compare = 1;
else if (!strcmp (p, "-Wno-sign-compare"))
warn_sign_compare = 0;
else if (!strcmp (p, "-Wall"))
/* We save the value of warn_uninitialized, since if they put
-Wuninitialized on the command line, we need to generate a
warning about not using it without also specifying -O. */
if (warn_uninitialized != 1)
warn_uninitialized = 2;
warn_implicit = 1;
warn_return_type = 1;
warn_unused = 1;
warn_switch = 1;
warn_format = 1;
warn_char_subscripts = 1;
warn_parentheses = 1;
warn_missing_braces = 1;
warn_sign_compare = 1;
/* We set this to 2 here, but 1 in -Wmain, so -ffreestanding can turn
it off only if it's not explicit. */
warn_main = 2;
return 0;
return 1;
/* Hooks for print_node. */
print_lang_decl (file, node, indent)
FILE *file;
tree node;
int indent;
print_lang_type (file, node, indent)
FILE *file;
tree node;
int indent;
print_lang_identifier (file, node, indent)
FILE *file;
tree node;
int indent;
print_node (file, "global", IDENTIFIER_GLOBAL_VALUE (node), indent + 4);
print_node (file, "local", IDENTIFIER_LOCAL_VALUE (node), indent + 4);
print_node (file, "label", IDENTIFIER_LABEL_VALUE (node), indent + 4);
print_node (file, "implicit", IDENTIFIER_IMPLICIT_DECL (node), indent + 4);
print_node (file, "error locus", IDENTIFIER_ERROR_LOCUS (node), indent + 4);
print_node (file, "limbo value", IDENTIFIER_LIMBO_VALUE (node), indent + 4);
/* Hook called at end of compilation to assume 1 elt
for a top-level array decl that wasn't complete before. */
finish_incomplete_decl (decl)
tree decl;
if (TREE_CODE (decl) == VAR_DECL)
tree type = TREE_TYPE (decl);
if (type != error_mark_node
&& TYPE_DOMAIN (type) == 0)
if (! DECL_EXTERNAL (decl))
warning_with_decl (decl, "array `%s' assumed to have one element");
complete_array_type (type, NULL_TREE, 1);
layout_decl (decl, 0);
/* Create a new `struct binding_level'. */
struct binding_level *
make_binding_level ()
return (struct binding_level *) xmalloc (sizeof (struct binding_level));
/* Nonzero if we are currently in the global binding level. */
global_bindings_p ()
return current_binding_level == global_binding_level;
keep_next_level ()
keep_next_level_flag = 1;
/* Nonzero if the current level needs to have a BLOCK made. */
kept_level_p ()
return ((current_binding_level->keep_if_subblocks
&& current_binding_level->blocks != 0)
|| current_binding_level->keep
|| current_binding_level->names != 0
|| (current_binding_level->tags != 0
&& !current_binding_level->tag_transparent));
/* Identify this binding level as a level of parameters.
DEFINITION_FLAG is 1 for a definition, 0 for a declaration.
But it turns out there is no way to pass the right value for
DEFINITION_FLAG, so we ignore it. */
declare_parm_level (definition_flag)
int definition_flag;
current_binding_level->parm_flag = 1;
/* Nonzero if currently making parm declarations. */
in_parm_level_p ()
return current_binding_level->parm_flag;
/* Enter a new binding level.
If TAG_TRANSPARENT is nonzero, do so only for the name space of variables,
not for that of tags. */
pushlevel (tag_transparent)
int tag_transparent;
register struct binding_level *newlevel = NULL_BINDING_LEVEL;
/* If this is the top level of a function,
just make sure that NAMED_LABELS is 0. */
if (current_binding_level == global_binding_level)
named_labels = 0;
/* Reuse or create a struct for this binding level. */
if (free_binding_level)
newlevel = free_binding_level;
free_binding_level = free_binding_level->level_chain;
newlevel = make_binding_level ();
/* Add this level to the front of the chain (stack) of levels that
are active. */
*newlevel = clear_binding_level;
= (tag_transparent
|| (current_binding_level
? current_binding_level->subblocks_tag_transparent
: 0));
newlevel->level_chain = current_binding_level;
current_binding_level = newlevel;
newlevel->keep = keep_next_level_flag;
keep_next_level_flag = 0;
newlevel->keep_if_subblocks = keep_next_if_subblocks;
keep_next_if_subblocks = 0;
/* Clear the limbo values of all identifiers defined in BLOCK or a subblock. */
static void
clear_limbo_values (block)
tree block;
tree tem;
for (tem = BLOCK_VARS (block); tem; tem = TREE_CHAIN (tem))
if (DECL_NAME (tem) != 0)
for (tem = BLOCK_SUBBLOCKS (block); tem; tem = TREE_CHAIN (tem))
clear_limbo_values (tem);
/* 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. */
poplevel (keep, reverse, functionbody)
int keep;
int reverse;
int functionbody;
register tree link;
/* The chain of decls was accumulated in reverse order.
Put it into forward order, just for cleanliness. */
tree decls;
tree tags = current_binding_level->tags;
tree subblocks = current_binding_level->blocks;
tree block = 0;
tree decl;
int block_previously_created;
keep |= current_binding_level->keep;
/* This warning is turned off because it causes warnings for
declarations like `extern struct foo *x'. */
#if 0
/* Warn about incomplete structure types in this level. */
for (link = tags; link; link = TREE_CHAIN (link))
if (TYPE_SIZE (TREE_VALUE (link)) == 0)
tree type = TREE_VALUE (link);
char *errmsg;
switch (TREE_CODE (type))
errmsg = "`struct %s' incomplete in scope ending here";
errmsg = "`union %s' incomplete in scope ending here";
errmsg = "`enum %s' incomplete in scope ending here";
error (errmsg, IDENTIFIER_POINTER (TYPE_NAME (type)));
/* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
error (errmsg, IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))));
#endif /* 0 */
/* Get the decls in the order they were written.
Usually current_binding_level->names is in reverse order.
But parameter decls were previously put in forward order. */
if (reverse)
= decls = nreverse (current_binding_level->names);
decls = current_binding_level->names;
/* Output any nested inline functions within this block
if they weren't already output. */
for (decl = decls; decl; decl = TREE_CHAIN (decl))
&& ! TREE_ASM_WRITTEN (decl)
&& DECL_INITIAL (decl) != 0
/* If this decl was copied from a file-scope decl
on account of a block-scope extern decl,
propagate TREE_ADDRESSABLE to the file-scope decl.
DECL_ABSTRACT_ORIGIN can be set to itself if warn_return_type is
true, since then the decl goes through save_for_inline_copying. */
if (DECL_ABSTRACT_ORIGIN (decl) != 0
&& DECL_ABSTRACT_ORIGIN (decl) != decl)
else if (DECL_SAVED_INSNS (decl) != 0)
push_function_context ();
output_inline_function (decl);
pop_function_context ();
/* If there were any declarations or structure tags in that level,
or if this level is a function body,
create a BLOCK to record them for the life of this function. */
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
|| (current_binding_level->keep_if_subblocks && subblocks != 0))
block = make_node (BLOCK);
if (block != 0)
BLOCK_VARS (block) = decls;
BLOCK_TYPE_TAGS (block) = tags;
BLOCK_SUBBLOCKS (block) = subblocks;
remember_end_note (block);
/* In each subblock, record that this is its superior. */
for (link = subblocks; link; link = TREE_CHAIN (link))
BLOCK_SUPERCONTEXT (link) = block;
/* Clear out the meanings of the local variables of this level. */
for (link = decls; link; link = TREE_CHAIN (link))
if (DECL_NAME (link) != 0)
/* If the ident. was used or addressed via a local extern decl,
don't forget that fact. */
if (DECL_EXTERNAL (link))
if (TREE_USED (link))
TREE_USED (DECL_NAME (link)) = 1;
/* Restore all name-meanings of the outer levels
that were shadowed by this level. */
for (link = current_binding_level->shadowed; link; link = TREE_CHAIN (link))
/* If the level being exited is the top level of a function,
check over all the labels, and clear out the current
(function local) meanings of their names. */
if (functionbody)
clear_limbo_values (block);
/* If this is the top level block of a function,
the vars are the function's parameters.
Don't leave them in the BLOCK because they are
found in the FUNCTION_DECL instead. */
BLOCK_VARS (block) = 0;
/* Clear out the definitions of all label names,
since their scopes end here,
and add them to BLOCK_VARS. */
for (link = named_labels; link; link = TREE_CHAIN (link))
register tree label = TREE_VALUE (link);
if (DECL_INITIAL (label) == 0)
error_with_decl (label, "label `%s' used but not defined");
/* Avoid crashing later. */
define_label (input_filename, lineno,
DECL_NAME (label));
else if (warn_unused && !TREE_USED (label))
warning_with_decl (label, "label `%s' defined but not used");
/* Put the labels into the "variables" of the
top-level block, so debugger can see them. */
TREE_CHAIN (label) = BLOCK_VARS (block);
BLOCK_VARS (block) = label;
/* Pop the current level, and free the structure for reuse. */
register 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;
/* Dispose of the block that we just made inside some higher level. */
if (functionbody)
DECL_INITIAL (current_function_decl) = block;
else if (block)
if (!block_previously_created)
= 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 (subblocks)
= chainon (current_binding_level->blocks, subblocks);
/* Set the TYPE_CONTEXTs for all of the tagged types belonging to this
binding contour so that they point to the appropriate construct, i.e.
either to the current FUNCTION_DECL node, or else to the BLOCK node
we just constructed.
Note that for tagged types whose scope is just the formal parameter
list for some function type specification, we can't properly set
their TYPE_CONTEXTs here, because we don't have a pointer to the
appropriate FUNCTION_TYPE node readily available to us. For those
cases, the TYPE_CONTEXTs of the relevant tagged type nodes get set
in `grokdeclarator' as soon as we have created the FUNCTION_TYPE
node which will represent the "scope" for these "parameter list local"
tagged types.
if (functionbody)
for (link = tags; link; link = TREE_CHAIN (link))
TYPE_CONTEXT (TREE_VALUE (link)) = current_function_decl;
else if (block)
for (link = tags; link; link = TREE_CHAIN (link))
TYPE_CONTEXT (TREE_VALUE (link)) = block;
if (block)
TREE_USED (block) = 1;
return block;
/* Delete the node BLOCK from the current binding level.
This is used for the block inside a stmt expr ({...})
so that the block can be reinserted where appropriate. */
delete_block (block)
tree block;
tree t;
if (current_binding_level->blocks == block)
current_binding_level->blocks = TREE_CHAIN (block);
for (t = current_binding_level->blocks; t;)
if (TREE_CHAIN (t) == block)
TREE_CHAIN (t) = TREE_CHAIN (block);
t = TREE_CHAIN (t);
TREE_CHAIN (block) = NULL;
/* Clear TREE_USED which is always set by poplevel.
The flag is set again if insert_block is called. */
TREE_USED (block) = 0;
/* 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. */
insert_block (block)
tree block;
TREE_USED (block) = 1;
= chainon (current_binding_level->blocks, block);
/* Set the BLOCK node for the innermost scope
(the one we are currently in). */
set_block (block)
register tree block;
current_binding_level->this_block = block;
push_label_level ()
register struct binding_level *newlevel;
/* Reuse or create a struct for this binding level. */
if (free_binding_level)
newlevel = free_binding_level;
free_binding_level = free_binding_level->level_chain;
newlevel = make_binding_level ();
/* Add this level to the front of the chain (stack) of label levels. */
newlevel->level_chain = label_level_chain;
label_level_chain = newlevel;
newlevel->names = named_labels;
newlevel->shadowed = shadowed_labels;
named_labels = 0;
shadowed_labels = 0;
pop_label_level ()
register struct binding_level *level = label_level_chain;
tree link, prev;
/* Clear out the definitions of the declared labels in this level.
Leave in the list any ordinary, non-declared labels. */
for (link = named_labels, prev = 0; link;)
if (DECL_SOURCE_LINE (TREE_VALUE (link)) == 0)
error_with_decl (TREE_VALUE (link),
"label `%s' used but not defined");
/* Avoid crashing later. */
define_label (input_filename, lineno,
else if (warn_unused && !TREE_USED (TREE_VALUE (link)))
warning_with_decl (TREE_VALUE (link),
"label `%s' defined but not used");
/* Delete this element from the list. */
link = TREE_CHAIN (link);
if (prev)
TREE_CHAIN (prev) = link;
named_labels = link;
prev = link;
link = TREE_CHAIN (link);
/* Bring back all the labels that were shadowed. */
for (link = shadowed_labels; link; link = TREE_CHAIN (link))
if (DECL_NAME (TREE_VALUE (link)) != 0)
= TREE_VALUE (link);
named_labels = chainon (named_labels, level->names);
shadowed_labels = level->shadowed;
/* Pop the current level, and free the structure for reuse. */
label_level_chain = label_level_chain->level_chain;
level->level_chain = free_binding_level;
free_binding_level = level;
/* Push a definition or a declaration of struct, union or enum tag "name".
"type" should be the type node.
We assume that the tag "name" is not already defined.
Note that the definition may really be just a forward reference.
In that case, the TYPE_SIZE will be zero. */
pushtag (name, type)
tree name, type;
register struct binding_level *b;
/* Find the proper binding level for this type tag. */
for (b = current_binding_level; b->tag_transparent; b = b->level_chain)
if (name)
/* Record the identifier as the type's name if it has none. */
if (TYPE_NAME (type) == 0)
TYPE_NAME (type) = name;
if (b == global_binding_level)
b->tags = perm_tree_cons (name, type, b->tags);
b->tags = saveable_tree_cons (name, type, b->tags);
/* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the
tagged type we just added to the current binding level. This fake
NULL-named TYPE_DECL node helps dwarfout.c to know when it needs
to output a representation of a tagged type, and it also gives
us a convenient place to record the "scope start" address for the
tagged type. */
TYPE_STUB_DECL (type) = pushdecl (build_decl (TYPE_DECL, NULL_TREE, type));
/* An approximation for now, so we can tell this is a function-scope tag.
This will be updated in poplevel. */
/* Handle when a new declaration NEWDECL
has the same name as an old one OLDDECL
in the same binding contour.
Prints an error message if appropriate.
If safely possible, alter OLDDECL to look like NEWDECL, and return 1.
Otherwise, return 0.
When DIFFERENT_BINDING_LEVEL is true, NEWDECL is an external declaration,
and OLDDECL is in an outer binding level and should thus not be changed. */
static int
duplicate_decls (newdecl, olddecl, different_binding_level)
register tree newdecl, olddecl;
int different_binding_level;
int types_match = comptypes (TREE_TYPE (newdecl), TREE_TYPE (olddecl));
int new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL
&& DECL_INITIAL (newdecl) != 0);
tree oldtype = TREE_TYPE (olddecl);
tree newtype = TREE_TYPE (newdecl);
char *errmsg = 0;
if (TREE_CODE_CLASS (TREE_CODE (olddecl)) == 'd')
if (TREE_CODE (newtype) == ERROR_MARK
|| TREE_CODE (oldtype) == ERROR_MARK)
types_match = 0;
/* New decl is completely inconsistent with the old one =>
tell caller to replace the old one.
This is always an error except in the case of shadowing a builtin. */
if (TREE_CODE (olddecl) != TREE_CODE (newdecl))
if (TREE_CODE (olddecl) == FUNCTION_DECL
&& (DECL_BUILT_IN (olddecl)
|| DECL_BUILT_IN_NONANSI (olddecl)))
/* If you declare a built-in or predefined function name as static,
the old definition is overridden,
but optionally warn this was a bad choice of name. */
if (!TREE_PUBLIC (newdecl))
if (!warn_shadow)
else if (DECL_BUILT_IN (olddecl))
warning_with_decl (newdecl, "shadowing built-in function `%s'");
warning_with_decl (newdecl, "shadowing library function `%s'");
/* Likewise, if the built-in is not ansi, then programs can
override it even globally without an error. */
else if (! DECL_BUILT_IN (olddecl))
warning_with_decl (newdecl,
"library function `%s' declared as non-function");
else if (DECL_BUILT_IN_NONANSI (olddecl))
warning_with_decl (newdecl,
"built-in function `%s' declared as non-function");
warning_with_decl (newdecl,
"built-in function `%s' declared as non-function");
error_with_decl (newdecl, "`%s' redeclared as different kind of symbol");
error_with_decl (olddecl, "previous declaration of `%s'");
return 0;
/* For real parm decl following a forward decl,
return 1 so old decl will be reused. */
if (types_match && TREE_CODE (newdecl) == PARM_DECL
&& TREE_ASM_WRITTEN (olddecl) && ! TREE_ASM_WRITTEN (newdecl))
return 1;
/* The new declaration is the same kind of object as the old one.
The declarations may partially match. Print warnings if they don't
match enough. Ultimately, copy most of the information from the new
decl to the old one, and keep using the old one. */
if (flag_traditional && TREE_CODE (newdecl) == FUNCTION_DECL
&& IDENTIFIER_IMPLICIT_DECL (DECL_NAME (newdecl)) == olddecl
&& DECL_INITIAL (olddecl) == 0)
/* If -traditional, avoid error for redeclaring fcn
after implicit decl. */
else if (TREE_CODE (olddecl) == FUNCTION_DECL
&& DECL_BUILT_IN (olddecl))
/* A function declaration for a built-in function. */
if (!TREE_PUBLIC (newdecl))
/* If you declare a built-in function name as static, the
built-in definition is overridden,
but optionally warn this was a bad choice of name. */
if (warn_shadow)
warning_with_decl (newdecl, "shadowing built-in function `%s'");
/* Discard the old built-in function. */
return 0;
else if (!types_match)
/* Accept the return type of the new declaration if same modes. */
tree oldreturntype = TREE_TYPE (oldtype);
tree newreturntype = TREE_TYPE (newtype);
/* Make sure we put the new type in the same obstack as the old ones.
If the old types are not both in the same obstack, use the
permanent one. */
if (TYPE_OBSTACK (oldtype) == TYPE_OBSTACK (newtype))
push_obstacks (TYPE_OBSTACK (oldtype), TYPE_OBSTACK (oldtype));
push_obstacks_nochange ();
end_temporary_allocation ();
if (TYPE_MODE (oldreturntype) == TYPE_MODE (newreturntype))
/* Function types may be shared, so we can't just modify
the return type of olddecl's function type. */
tree trytype
= build_function_type (newreturntype,
TYPE_ARG_TYPES (oldtype));
types_match = comptypes (newtype, trytype);
if (types_match)
oldtype = trytype;
/* Accept harmless mismatch in first argument type also.
This is for ffs. */
if (TYPE_ARG_TYPES (TREE_TYPE (newdecl)) != 0
&& TYPE_ARG_TYPES (oldtype) != 0
&& TREE_VALUE (TYPE_ARG_TYPES (newtype)) != 0
&& TREE_VALUE (TYPE_ARG_TYPES (oldtype)) != 0
/* Function types may be shared, so we can't just modify
the return type of olddecl's function type. */
tree trytype
= build_function_type (TREE_TYPE (oldtype),
tree_cons (NULL_TREE,
types_match = comptypes (newtype, trytype);
if (types_match)
oldtype = trytype;
if (! different_binding_level)
TREE_TYPE (olddecl) = oldtype;
pop_obstacks ();
if (!types_match)
/* If types don't match for a built-in, throw away the built-in. */
warning_with_decl (newdecl, "conflicting types for built-in function `%s'");
return 0;
else if (TREE_CODE (olddecl) == FUNCTION_DECL
&& DECL_SOURCE_LINE (olddecl) == 0)
/* A function declaration for a predeclared function
that isn't actually built in. */
if (!TREE_PUBLIC (newdecl))
/* If you declare it as static, the
default definition is overridden. */
return 0;
else if (!types_match)
/* If the types don't match, preserve volatility indication.
Later on, we will discard everything else about the
default declaration. */
/* Permit char *foo () to match void *foo (...) if not pedantic,
if one of them came from a system header file. */
else if (!types_match
&& ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (newtype))) == void_type_node
&& TYPE_ARG_TYPES (oldtype) == 0
&& self_promoting_args_p (TYPE_ARG_TYPES (newtype))
&& TREE_TYPE (TREE_TYPE (oldtype)) == char_type_node)
(TREE_TYPE (TREE_TYPE (newtype)) == char_type_node
&& TYPE_ARG_TYPES (newtype) == 0
&& self_promoting_args_p (TYPE_ARG_TYPES (oldtype))
&& TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (oldtype))) == void_type_node)))
if (pedantic)
pedwarn_with_decl (newdecl, "conflicting types for `%s'");
/* Make sure we keep void * as ret type, not char *. */
if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (oldtype))) == void_type_node)
TREE_TYPE (newdecl) = newtype = oldtype;
/* Set DECL_IN_SYSTEM_HEADER, so that if we see another declaration
we will come back here again. */
DECL_IN_SYSTEM_HEADER (newdecl) = 1;
else if (!types_match
/* Permit char *foo (int, ...); followed by char *foo ();
if not pedantic. */
&& ! (TREE_CODE (olddecl) == FUNCTION_DECL
&& ! pedantic
/* Return types must still match. */
&& comptypes (TREE_TYPE (oldtype),
TREE_TYPE (newtype))
&& TYPE_ARG_TYPES (newtype) == 0))
error_with_decl (newdecl, "conflicting types for `%s'");
/* Check for function type mismatch
involving an empty arglist vs a nonempty one. */
if (TREE_CODE (olddecl) == FUNCTION_DECL
&& comptypes (TREE_TYPE (oldtype),
TREE_TYPE (newtype))
&& ((TYPE_ARG_TYPES (oldtype) == 0
&& DECL_INITIAL (olddecl) == 0)
(TYPE_ARG_TYPES (newtype) == 0
&& DECL_INITIAL (newdecl) == 0)))
/* Classify the problem further. */
register tree t = TYPE_ARG_TYPES (oldtype);
if (t == 0)
t = TYPE_ARG_TYPES (newtype);
for (; t; t = TREE_CHAIN (t))
register tree type = TREE_VALUE (t);
if (TREE_CHAIN (t) == 0
&& TYPE_MAIN_VARIANT (type) != void_type_node)
error ("A parameter list with an ellipsis can't match");
error ("an empty parameter name list declaration.");
if (TYPE_MAIN_VARIANT (type) == float_type_node
error ("An argument type that has a default promotion");
error ("can't match an empty parameter name list declaration.");
error_with_decl (olddecl, "previous declaration of `%s'");
errmsg = redeclaration_error_message (newdecl, olddecl);
if (errmsg)
error_with_decl (newdecl, errmsg);
error_with_decl (olddecl,
((DECL_INITIAL (olddecl)
&& current_binding_level == global_binding_level)
? "`%s' previously defined here"
: "`%s' previously declared here"));
else if (TREE_CODE (newdecl) == TYPE_DECL
|| DECL_IN_SYSTEM_HEADER (newdecl)))
warning_with_decl (newdecl, "redefinition of `%s'");
((DECL_INITIAL (olddecl)
&& current_binding_level == global_binding_level)
? "`%s' previously defined here"
: "`%s' previously declared here"));
else if (TREE_CODE (olddecl) == FUNCTION_DECL
&& DECL_INITIAL (olddecl) != 0
&& TYPE_ARG_TYPES (oldtype) == 0
&& TYPE_ARG_TYPES (newtype) != 0
&& TYPE_ACTUAL_ARG_TYPES (oldtype) != 0)
register tree type, parm;
register int nargs;
/* Prototype decl follows defn w/o prototype. */
for (parm = TYPE_ACTUAL_ARG_TYPES (oldtype),
type = TYPE_ARG_TYPES (newtype),
nargs = 1;
(TYPE_MAIN_VARIANT (TREE_VALUE (parm)) != void_type_node
|| TYPE_MAIN_VARIANT (TREE_VALUE (type)) != void_type_node);
parm = TREE_CHAIN (parm), type = TREE_CHAIN (type), nargs++)
if (TYPE_MAIN_VARIANT (TREE_VALUE (parm)) == void_type_node
|| TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node)
errmsg = "prototype for `%s' follows and number of arguments";
/* Type for passing arg must be consistent
with that declared for the arg. */
if (! comptypes (TREE_VALUE (parm), TREE_VALUE (type))
/* If -traditional, allow `unsigned int' instead of `int'
in the prototype. */
&& (! (flag_traditional
&& TYPE_MAIN_VARIANT (TREE_VALUE (parm)) == integer_type_node
&& TYPE_MAIN_VARIANT (TREE_VALUE (type)) == unsigned_type_node)))
errmsg = "prototype for `%s' follows and argument %d";
if (errmsg)
error_with_decl (newdecl, errmsg, nargs);
error_with_decl (olddecl,
"doesn't match non-prototype definition here");
warning_with_decl (newdecl, "prototype for `%s' follows");
warning_with_decl (olddecl, "non-prototype definition here");
/* Warn about mismatches in various flags. */
/* Warn if function is now inline
but was previously declared not inline and has been called. */
if (TREE_CODE (olddecl) == FUNCTION_DECL
&& ! DECL_INLINE (olddecl) && DECL_INLINE (newdecl)
&& TREE_USED (olddecl))
warning_with_decl (newdecl,
"`%s' declared inline after being called");
if (TREE_CODE (olddecl) == FUNCTION_DECL
&& ! DECL_INLINE (olddecl) && DECL_INLINE (newdecl)
&& DECL_INITIAL (olddecl) != 0)
warning_with_decl (newdecl,
"`%s' declared inline after its definition");
/* If pedantic, warn when static declaration follows a non-static
declaration. Otherwise, do so only for functions. */
if ((pedantic || TREE_CODE (olddecl) == FUNCTION_DECL)
&& TREE_PUBLIC (olddecl)
&& !TREE_PUBLIC (newdecl))
warning_with_decl (newdecl, "static declaration for `%s' follows non-static");
/* Warn when const declaration follows a non-const
declaration, but not for functions. */
if (TREE_CODE (olddecl) != FUNCTION_DECL
&& !TREE_READONLY (olddecl)
&& TREE_READONLY (newdecl))
warning_with_decl (newdecl, "const declaration for `%s' follows non-const");
/* These bits are logically part of the type, for variables.
But not for functions
(where qualifiers are not valid ANSI anyway). */
else if (pedantic && TREE_CODE (olddecl) != FUNCTION_DECL
&& (TREE_READONLY (newdecl) != TREE_READONLY (olddecl)
|| TREE_THIS_VOLATILE (newdecl) != TREE_THIS_VOLATILE (olddecl)))
pedwarn_with_decl (newdecl, "type qualifiers for `%s' conflict with previous decl");
/* Optionally warn about more than one declaration for the same name. */
if (errmsg == 0 && warn_redundant_decls && DECL_SOURCE_LINE (olddecl) != 0
/* Dont warn about a function declaration
followed by a definition. */
&& !(TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl) != 0
&& DECL_INITIAL (olddecl) == 0)
/* Don't warn about extern decl followed by (tentative) definition. */
&& !(DECL_EXTERNAL (olddecl) && ! DECL_EXTERNAL (newdecl)))
warning_with_decl (newdecl, "redundant redeclaration of `%s' in same scope");
warning_with_decl (olddecl, "previous declaration of `%s'");
/* Copy all the DECL_... slots specified in the new decl
except for any that we copy here from the old type.
Past this point, we don't change OLDTYPE and NEWTYPE
even if we change the types of NEWDECL and OLDDECL. */
if (types_match)
/* When copying info to olddecl, we store into write_olddecl
instead. This allows us to avoid modifying olddecl when
different_binding_level is true. */
tree write_olddecl = different_binding_level ? newdecl : olddecl;
/* Make sure we put the new type in the same obstack as the old ones.
If the old types are not both in the same obstack, use the permanent
one. */
if (TYPE_OBSTACK (oldtype) == TYPE_OBSTACK (newtype))
push_obstacks (TYPE_OBSTACK (oldtype), TYPE_OBSTACK (oldtype));
push_obstacks_nochange ();
end_temporary_allocation ();
/* Merge the data types specified in the two decls. */
if (TREE_CODE (newdecl) != FUNCTION_DECL || !DECL_BUILT_IN (olddecl))
if (different_binding_level)
TREE_TYPE (newdecl)
= build_type_attribute_variant
merge_attributes (TYPE_ATTRIBUTES (newtype),
TYPE_ATTRIBUTES (oldtype)));
TREE_TYPE (newdecl)
= TREE_TYPE (olddecl)
= common_type (newtype, oldtype);
/* Lay the type out, unless already done. */
if (oldtype != TREE_TYPE (newdecl))
if (TREE_TYPE (newdecl) != error_mark_node)
layout_type (TREE_TYPE (newdecl));
if (TREE_CODE (newdecl) != FUNCTION_DECL
&& TREE_CODE (newdecl) != TYPE_DECL
&& TREE_CODE (newdecl) != CONST_DECL)
layout_decl (newdecl, 0);
/* Since the type is OLDDECL's, make OLDDECL's size go with. */
DECL_SIZE (newdecl) = DECL_SIZE (olddecl);
if (TREE_CODE (olddecl) != FUNCTION_DECL)
if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl))
DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl);
/* Keep the old rtl since we can safely use it. */
DECL_RTL (newdecl) = DECL_RTL (olddecl);
/* Merge the type qualifiers. */
&& !TREE_THIS_VOLATILE (newdecl))
TREE_THIS_VOLATILE (write_olddecl) = 0;
if (TREE_READONLY (newdecl))
TREE_READONLY (write_olddecl) = 1;
if (TREE_THIS_VOLATILE (newdecl))
TREE_THIS_VOLATILE (write_olddecl) = 1;
if (TREE_CODE (newdecl) == VAR_DECL)
make_var_volatile (newdecl);
/* Keep source location of definition rather than declaration. */
/* When called with different_binding_level set, keep the old
information so that meaningful diagnostics can be given. */
if (DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0
&& ! different_binding_level)
DECL_SOURCE_LINE (newdecl) = DECL_SOURCE_LINE (olddecl);
DECL_SOURCE_FILE (newdecl) = DECL_SOURCE_FILE (olddecl);
/* Merge the unused-warning information. */
if (DECL_IN_SYSTEM_HEADER (olddecl))
DECL_IN_SYSTEM_HEADER (newdecl) = 1;
else if (DECL_IN_SYSTEM_HEADER (newdecl))
DECL_IN_SYSTEM_HEADER (write_olddecl) = 1;
/* Merge the initialization information. */
/* When called with different_binding_level set, don't copy over
DECL_INITIAL, so that we don't accidentally change function
declarations into function definitions. */
if (DECL_INITIAL (newdecl) == 0 && ! different_binding_level)
DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
/* Merge the section attribute.
We want to issue an error if the sections conflict but that must be
done later in decl_attributes since we are called before attributes
are assigned. */
if (TREE_CODE (newdecl) == FUNCTION_DECL)
pop_obstacks ();
/* If cannot merge, then use the new type and qualifiers,
and don't preserve the old rtl. */
else if (! different_binding_level)
TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
TREE_READONLY (olddecl) = TREE_READONLY (newdecl);
/* Merge the storage class information. */
DECL_WEAK (newdecl) |= DECL_WEAK (olddecl);
/* For functions, static overrides non-static. */
if (TREE_CODE (newdecl) == FUNCTION_DECL)
TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl);
/* This is since we don't automatically
copy the attributes of NEWDECL into OLDDECL. */
/* No need to worry about different_binding_level here because
then TREE_PUBLIC (newdecl) was true. */
TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
/* If this clears `static', clear it in the identifier too. */
if (! TREE_PUBLIC (olddecl))
TREE_PUBLIC (DECL_NAME (olddecl)) = 0;
if (DECL_EXTERNAL (newdecl))
TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl);
/* An extern decl does not override previous storage class. */
TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl);
if (! DECL_EXTERNAL (newdecl))
DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl);
TREE_STATIC (olddecl) = TREE_STATIC (newdecl);
TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
/* If either decl says `inline', this fn is inline,
unless its definition was passed already. */
if (DECL_INLINE (newdecl) && DECL_INITIAL (olddecl) == 0)
DECL_INLINE (olddecl) = 1;
DECL_INLINE (newdecl) = DECL_INLINE (olddecl);
if (TREE_CODE (newdecl) == FUNCTION_DECL)
if (DECL_BUILT_IN (olddecl))
/* Get rid of any built-in function if new arg types don't match it
or if we have a function definition. */
if (! types_match || new_is_definition)
if (! different_binding_level)
TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
DECL_BUILT_IN (olddecl) = 0;
/* If redeclaring a builtin function, and not a definition,
it stays built in. */
DECL_BUILT_IN (newdecl) = 1;
/* Also preserve various other info from the definition. */
else if (! new_is_definition)
DECL_FRAME_SIZE (newdecl) = DECL_FRAME_SIZE (olddecl);
if (! new_is_definition)
DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
/* When called with different_binding_level set, don't copy over
DECL_INITIAL, so that we don't accidentally change function
declarations into function definitions. */
if (! different_binding_level)
DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
DECL_SAVED_INSNS (newdecl) = DECL_SAVED_INSNS (olddecl);
DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl);
if (DECL_INLINE (newdecl))
DECL_ABSTRACT_ORIGIN (newdecl) = olddecl;
if (different_binding_level)
/* Don't output a duplicate symbol for this declaration. */
TREE_ASM_WRITTEN (newdecl) = 1;
return 0;
/* Copy most of the decl-specific fields of NEWDECL into OLDDECL.
But preserve OLDdECL's DECL_UID. */
register unsigned olddecl_uid = DECL_UID (olddecl);
bcopy ((char *) newdecl + sizeof (struct tree_common),
(char *) olddecl + sizeof (struct tree_common),
sizeof (struct tree_decl) - sizeof (struct tree_common));
DECL_UID (olddecl) = olddecl_uid;
return 1;
/* Record a decl-node X as belonging to the current lexical scope.
Check for errors (such as an incompatible declaration for the same
name already seen in the same scope).
Returns either X or an old decl for the same name.
If an old decl is returned, it may have been smashed
to agree with what X says. */
pushdecl (x)
tree x;
register tree t;
register tree name = DECL_NAME (x);
register struct binding_level *b = current_binding_level;
DECL_CONTEXT (x) = current_function_decl;
/* A local extern declaration for a function doesn't constitute nesting.
A local auto declaration does, since it's a forward decl
for a nested function coming later. */
if (warn_nested_externs && DECL_EXTERNAL (x) && b != global_binding_level
/* Don't print error messages for __FUNCTION__ and __PRETTY_FUNCTION__ */
warning ("nested extern declaration of `%s'", IDENTIFIER_POINTER (name));
if (name)
char *file;
int line;
int different_binding_level = 0;
t = lookup_name_current_level (name);
/* Don't type check externs here when -traditional. This is so that
code with conflicting declarations inside blocks will get warnings
not errors. X11 for instance depends on this. */
if (! t && DECL_EXTERNAL (x) && TREE_PUBLIC (x) && ! flag_traditional)
/* Type decls at global scope don't conflict with externs declared
inside lexical blocks. */
if (t && TREE_CODE (t) == TYPE_DECL)
t = 0;
different_binding_level = 1;
if (t != 0 && t == error_mark_node)
/* error_mark_node is 0 for a while during initialization! */
t = 0;
error_with_decl (x, "`%s' used prior to declaration");
if (t != 0)
file = DECL_SOURCE_FILE (t);
line = DECL_SOURCE_LINE (t);
/* If this decl is `static' and an implicit decl was seen previously,
warn. But don't complain if -traditional,
since traditional compilers don't complain. */
if (! flag_traditional && TREE_PUBLIC (name)
/* Don't test for DECL_EXTERNAL, because grokdeclarator
sets this for all functions. */
&& ! TREE_PUBLIC (x)
&& (TREE_CODE (x) == FUNCTION_DECL || b == global_binding_level)
/* We used to warn also for explicit extern followed by static,
but sometimes you need to do it that way. */
pedwarn ("`%s' was declared implicitly `extern' and later `static'",
"previous declaration of `%s'",
if (t != 0 && duplicate_decls (x, t, different_binding_level))
/* Don't allow more than one "real" duplicate
of a forward parm decl. */
return t;
return t;
/* If we are processing a typedef statement, generate a whole new
..._TYPE node (which will be just an variant of the existing
..._TYPE node with identical properties) and then install the
TYPE_DECL node generated to represent the typedef name as the
TYPE_NAME of this brand new (duplicate) ..._TYPE node.
The whole point here is to end up with a situation where each
and every ..._TYPE node the compiler creates will be uniquely
associated with AT MOST one node representing a typedef name.
This way, even though the compiler substitutes corresponding
..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
early on, later parts of the compiler can always do the reverse
translation and get back the corresponding typedef name. For
example, given:
typedef struct S MY_TYPE;
MY_TYPE object;
Later parts of the compiler might only know that `object' was of
type `struct S' if if were not for code just below. With this
code however, later parts of the compiler see something like:
struct S' == struct S
typedef struct S' MY_TYPE;
struct S' object;
And they can then deduce (from the node for type struct S') that
the original object declaration was:
MY_TYPE object;
Being able to do this is important for proper support of protoize,
and also for generating precise symbolic debugging information
which takes full account of the programmer's (typedef) vocabulary.
Obviously, we don't want to generate a duplicate ..._TYPE node if
the TYPE_DECL node that we are now processing really represents a
standard built-in type.
Since all standard types are effectively declared at line zero
in the source file, we can easily check to see if we are working
on a standard type by checking the current value of lineno. */
if (DECL_SOURCE_LINE (x) == 0)
if (TYPE_NAME (TREE_TYPE (x)) == 0)
else if (TREE_TYPE (x) != error_mark_node)
tree tt = TREE_TYPE (x);
tt = build_type_copy (tt);
TYPE_NAME (tt) = x;
TREE_TYPE (x) = tt;
/* Multiple external decls of the same identifier ought to match.
Check against both global declarations (when traditional) and out of
scope (limbo) block level declarations.
We get warnings about inline functions where they are defined.
Avoid duplicate warnings where they are used. */
if (TREE_PUBLIC (x) && ! DECL_INLINE (x))
tree decl;
if (flag_traditional && IDENTIFIER_GLOBAL_VALUE (name) != 0
else if (IDENTIFIER_LIMBO_VALUE (name) != 0)
/* Decls in limbo are always extern, so no need to check that. */
decl = 0;
if (decl && ! comptypes (TREE_TYPE (x), TREE_TYPE (decl))
/* If old decl is built-in, we already warned if we should. */
&& !DECL_BUILT_IN (decl))
pedwarn_with_decl (x,
"type mismatch with previous external decl");
pedwarn_with_decl (decl, "previous external decl of `%s'");
/* If a function has had an implicit declaration, and then is defined,
make sure they are compatible. */
&& ! comptypes (TREE_TYPE (x),
warning_with_decl (x, "type mismatch with previous implicit declaration");
warning_with_decl (IDENTIFIER_IMPLICIT_DECL (name),
"previous implicit declaration of `%s'");
/* In PCC-compatibility mode, extern decls of vars with no current decl
take effect at top level no matter where they are. */
if (flag_traditional && DECL_EXTERNAL (x)
&& lookup_name (name) == 0)
tree type = TREE_TYPE (x);
/* But don't do this if the type contains temporary nodes. */
while (type)
if (type == error_mark_node)
if (! TREE_PERMANENT (type))
warning_with_decl (x, "type of external `%s' is not global");
/* By exiting the loop early, we leave TYPE nonzero,
and thus prevent globalization of the decl. */
else if (TREE_CODE (type) == FUNCTION_TYPE
&& TYPE_ARG_TYPES (type) != 0)
/* The types might not be truly local,
but the list of arg types certainly is temporary.
Since prototypes are nontraditional,
ok not to do the traditional thing. */
type = TREE_TYPE (type);
if (type == 0)
b = global_binding_level;
/* This name is new in its binding level.
Install the new declaration and return it. */
if (b == global_binding_level)
/* Install a global value. */
/* If the first global decl has external linkage,
warn if we later see static one. */
TREE_PUBLIC (name) = 1;
/* We no longer care about any previous block level declarations. */
/* Don't forget if the function was used via an implicit decl. */
TREE_USED (x) = 1, TREE_USED (name) = 1;
/* Don't forget if its address was taken in that way. */
/* Warn about mismatches against previous implicit decl. */
/* If this real decl matches the implicit, don't complain. */
== integer_type_node)))
pedwarn ("`%s' was previously implicitly declared to return `int'",
/* If this decl is `static' and an `extern' was seen previously,
that is erroneous. */
if (TREE_PUBLIC (name)
&& ! TREE_PUBLIC (x) && ! DECL_EXTERNAL (x))
/* Okay to redeclare an ANSI built-in as static. */
if (t != 0 && DECL_BUILT_IN (t))
/* Okay to declare a non-ANSI built-in as anything. */
else if (t != 0 && DECL_BUILT_IN_NONANSI (t))
/* Okay to have global type decl after an earlier extern
declaration inside a lexical block. */
else if (TREE_CODE (x) == TYPE_DECL)
pedwarn ("`%s' was declared implicitly `extern' and later `static'",
pedwarn ("`%s' was declared `extern' and later `static'",
/* Here to install a non-global value. */
tree oldlocal = IDENTIFIER_LOCAL_VALUE (name);
tree oldglobal = IDENTIFIER_GLOBAL_VALUE (name);
/* If this is an extern function declaration, see if we
have a global definition or declaration for the function. */
if (oldlocal == 0
&& oldglobal != 0
&& TREE_CODE (oldglobal) == FUNCTION_DECL)
/* We have one. Their types must agree. */
if (! comptypes (TREE_TYPE (x),
pedwarn_with_decl (x, "extern declaration of `%s' doesn't match global one");
/* Inner extern decl is inline if global one is.
Copy enough to really inline it. */
if (DECL_INLINE (oldglobal))
DECL_INLINE (x) = DECL_INLINE (oldglobal);
DECL_INITIAL (x) = (current_function_decl == oldglobal
? 0 : DECL_INITIAL (oldglobal));
DECL_RESULT (x) = DECL_RESULT (oldglobal);
DECL_ABSTRACT_ORIGIN (x) = oldglobal;
/* Inner extern decl is built-in if global one is. */
if (DECL_BUILT_IN (oldglobal))
DECL_BUILT_IN (x) = DECL_BUILT_IN (oldglobal);
/* Keep the arg types from a file-scope fcn defn. */
if (TYPE_ARG_TYPES (TREE_TYPE (oldglobal)) != 0
&& DECL_INITIAL (oldglobal)
TREE_TYPE (x) = TREE_TYPE (oldglobal);
#if 0 /* This case is probably sometimes the right thing to do. */
/* If we have a local external declaration,
then any file-scope declaration should not
have been static. */
if (oldlocal == 0 && oldglobal != 0
&& !TREE_PUBLIC (oldglobal)
warning ("`%s' locally external but globally static",
/* If we have a local external declaration,
and no file-scope declaration has yet been seen,
then if we later have a file-scope decl it must not be static. */
if (oldlocal == 0
if (oldglobal == 0)
TREE_PUBLIC (name) = 1;
/* Save this decl, so that we can do type checking against
other decls after it falls out of scope.
Only save it once. This prevents temporary decls created in
expand_inline_function from being used here, since this
will have been set when the inline function was parsed.
It also helps give slightly better warnings. */
/* Warn if shadowing an argument at the top level of the body. */
if (oldlocal != 0 && !DECL_EXTERNAL (x)
/* This warning doesn't apply to the parms of a nested fcn. */
&& ! current_binding_level->parm_flag
/* Check that this is one level down from the parms. */
&& current_binding_level->level_chain->parm_flag
/* Check that the decl being shadowed
comes from the parm level, one level up. */
&& chain_member (oldlocal, current_binding_level->level_chain->names))
if (TREE_CODE (oldlocal) == PARM_DECL)
pedwarn ("declaration of `%s' shadows a parameter",
pedwarn ("declaration of `%s' shadows a symbol from the parameter list",
/* Maybe warn if shadowing something else. */
else if (warn_shadow && !DECL_EXTERNAL (x)
/* No shadow warnings for internally generated vars. */
&& DECL_SOURCE_LINE (x) != 0
/* No shadow warnings for vars made for inlining. */
char *warnstring = 0;
&& current_binding_level->level_chain->parm_flag)
/* Don't warn about the parm names in function declarator
within a function declarator.
It would be nice to avoid warning in any function
declarator in a declaration, as opposed to a definition,
but there is no way to tell it's not a definition. */
else if (oldlocal != 0 && TREE_CODE (oldlocal) == PARM_DECL)
warnstring = "declaration of `%s' shadows a parameter";
else if (oldlocal != 0)
warnstring = "declaration of `%s' shadows previous local";
else if (IDENTIFIER_GLOBAL_VALUE (name) != 0
&& IDENTIFIER_GLOBAL_VALUE (name) != error_mark_node)
warnstring = "declaration of `%s' shadows global declaration";
if (warnstring)
warning (warnstring, IDENTIFIER_POINTER (name));
/* If storing a local value, there may already be one (inherited).
If so, record it for restoration when this binding level ends. */
if (oldlocal != 0)
b->shadowed = tree_cons (name, oldlocal, b->shadowed);
/* Keep count of variables in this level with incomplete type. */
if (TYPE_SIZE (TREE_TYPE (x)) == 0)
/* Put decls on list in reverse order.
We will reverse them later if necessary. */
TREE_CHAIN (x) = b->names;
b->names = x;
return x;
/* Like pushdecl, only it places X in GLOBAL_BINDING_LEVEL, if appropriate. */
pushdecl_top_level (x)
tree x;
register tree t;
register struct binding_level *b = current_binding_level;
current_binding_level = global_binding_level;
t = pushdecl (x);
current_binding_level = b;
return t;
/* Generate an implicit declaration for identifier FUNCTIONID
as a function of type int (). Print a warning if appropriate. */
implicitly_declare (functionid)
tree functionid;
register tree decl;
int traditional_warning = 0;
/* Only one "implicit declaration" warning per identifier. */
int implicit_warning;
/* Save the decl permanently so we can warn if definition follows. */
push_obstacks_nochange ();
end_temporary_allocation ();
/* We used to reuse an old implicit decl here,
but this loses with inline functions because it can clobber
the saved decl chains. */
/* if (IDENTIFIER_IMPLICIT_DECL (functionid) != 0)
decl = IDENTIFIER_IMPLICIT_DECL (functionid);
else */
decl = build_decl (FUNCTION_DECL, functionid, default_function_type);
/* Warn of implicit decl following explicit local extern decl.
This is probably a program designed for traditional C. */
if (TREE_PUBLIC (functionid) && IDENTIFIER_GLOBAL_VALUE (functionid) == 0)
traditional_warning = 1;
/* Warn once of an implicit declaration. */
implicit_warning = (IDENTIFIER_IMPLICIT_DECL (functionid) == 0);
DECL_EXTERNAL (decl) = 1;
TREE_PUBLIC (decl) = 1;
/* Record that we have an implicit decl and this is it. */
IDENTIFIER_IMPLICIT_DECL (functionid) = decl;
/* ANSI standard says implicit declarations are in the innermost block.
So we record the decl in the standard fashion.
If flag_traditional is set, pushdecl does it top-level. */
pushdecl (decl);
/* This is a no-op in c-lang.c or something real in objc-actions.c. */
maybe_objc_check_decl (decl);
rest_of_decl_compilation (decl, NULL_PTR, 0, 0);
if (warn_implicit && implicit_warning)
warning ("implicit declaration of function `%s'",
else if (warn_traditional && traditional_warning)
warning ("function `%s' was previously declared within a block",
/* Write a record describing this implicit function declaration to the
prototypes file (if requested). */
gen_aux_info_record (decl, 0, 1, 0);
pop_obstacks ();
return decl;
/* Return zero if the declaration NEWDECL is valid
when the declaration OLDDECL (assumed to be for the same name)
has already been seen.
Otherwise return an error message format string with a %s
where the identifier should go. */
static char *
redeclaration_error_message (newdecl, olddecl)
tree newdecl, olddecl;
if (TREE_CODE (newdecl) == TYPE_DECL)
if (flag_traditional && TREE_TYPE (newdecl) == TREE_TYPE (olddecl))
return 0;
/* pushdecl creates distinct types for TYPE_DECLs by calling
build_type_copy, so the above comparison generally fails. We do
another test against the TYPE_MAIN_VARIANT of the olddecl, which
is equivalent to what this code used to do before the build_type_copy
call. The variant type distinction should not matter for traditional
code, because it doesn't have type qualifiers. */
if (flag_traditional
&& TYPE_MAIN_VARIANT (TREE_TYPE (olddecl)) == TREE_TYPE (newdecl))
return 0;
return 0;
return "redefinition of `%s'";
else if (TREE_CODE (newdecl) == FUNCTION_DECL)
/* Declarations of functions can insist on internal linkage
but they can't be inconsistent with internal linkage,
so there can be no error on that account.
However defining the same name twice is no good. */
if (DECL_INITIAL (olddecl) != 0 && DECL_INITIAL (newdecl) != 0
/* However, defining once as extern inline and a second
time in another way is ok. */
&& !(DECL_INLINE (olddecl) && DECL_EXTERNAL (olddecl)
&& !(DECL_INLINE (newdecl) && DECL_EXTERNAL (newdecl))))
return "redefinition of `%s'";
return 0;
else if (current_binding_level == global_binding_level)
/* Objects declared at top level: */
/* If at least one is a reference, it's ok. */
if (DECL_EXTERNAL (newdecl) || DECL_EXTERNAL (olddecl))
return 0;
/* Reject two definitions. */
if (DECL_INITIAL (olddecl) != 0 && DECL_INITIAL (newdecl) != 0)
return "redefinition of `%s'";
/* Now we have two tentative defs, or one tentative and one real def. */
/* Insist that the linkage match. */
if (TREE_PUBLIC (olddecl) != TREE_PUBLIC (newdecl))
return "conflicting declarations of `%s'";
return 0;
else if (current_binding_level->parm_flag
&& TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl))
return 0;
/* Newdecl has block scope. If olddecl has block scope also, then
reject two definitions, and reject a definition together with an
external reference. Otherwise, it is OK, because newdecl must
be an extern reference to olddecl. */
if (!(DECL_EXTERNAL (newdecl) && DECL_EXTERNAL (olddecl))
&& DECL_CONTEXT (newdecl) == DECL_CONTEXT (olddecl))
return "redeclaration of `%s'";
return 0;
/* Get the LABEL_DECL corresponding to identifier ID as a label.
Create one if none exists so far for the current function.
This function is called for both label definitions and label references. */
lookup_label (id)
tree id;
register tree decl = IDENTIFIER_LABEL_VALUE (id);
if (current_function_decl == 0)
error ("label %s referenced outside of any function",
return 0;
/* Use a label already defined or ref'd with this name. */
if (decl != 0)
/* But not if it is inherited and wasn't declared to be inheritable. */
if (DECL_CONTEXT (decl) != current_function_decl
return shadow_label (id);
return decl;
decl = build_decl (LABEL_DECL, id, void_type_node);
/* Make sure every label has an rtx. */
label_rtx (decl);
/* A label not explicitly declared must be local to where it's ref'd. */
DECL_CONTEXT (decl) = current_function_decl;
DECL_MODE (decl) = VOIDmode;
/* Say where one reference is to the label,
for the sake of the error if it is not defined. */
DECL_SOURCE_LINE (decl) = lineno;
DECL_SOURCE_FILE (decl) = input_filename;
named_labels = tree_cons (NULL_TREE, decl, named_labels);
return decl;
/* Make a label named NAME in the current function,
shadowing silently any that may be inherited from containing functions
or containing scopes.
Note that valid use, if the label being shadowed
comes from another scope in the same function,
requires calling declare_nonlocal_label right away. */
shadow_label (name)
tree name;
register tree decl = IDENTIFIER_LABEL_VALUE (name);
if (decl != 0)
register tree dup;
/* Check to make sure that the label hasn't already been declared
at this label scope */
for (dup = named_labels; dup; dup = TREE_CHAIN (dup))
if (TREE_VALUE (dup) == decl)
error ("duplicate label declaration `%s'",
error_with_decl (TREE_VALUE (dup),
"this is a previous declaration");
/* Just use the previous declaration. */
return lookup_label (name);
shadowed_labels = tree_cons (NULL_TREE, decl, shadowed_labels);
IDENTIFIER_LABEL_VALUE (name) = decl = 0;
return lookup_label (name);
/* Define a label, specifying the location in the source file.
Return the LABEL_DECL node for the label, if the definition is valid.
Otherwise return 0. */
define_label (filename, line, name)
char *filename;
int line;
tree name;
tree decl = lookup_label (name);
/* If label with this name is known from an outer context, shadow it. */
if (decl != 0 && DECL_CONTEXT (decl) != current_function_decl)
shadowed_labels = tree_cons (NULL_TREE, decl, shadowed_labels);
decl = lookup_label (name);
if (DECL_INITIAL (decl) != 0)
error ("duplicate label `%s'", IDENTIFIER_POINTER (name));
return 0;
/* Mark label as having been defined. */
DECL_INITIAL (decl) = error_mark_node;
/* Say where in the source. */
DECL_SOURCE_FILE (decl) = filename;
DECL_SOURCE_LINE (decl) = line;
return decl;
/* Return the list of declarations of the current level.
Note that this list is in reverse order unless/until
you nreverse it; and when you do nreverse it, you must
store the result back using `storedecls' or you will lose. */
getdecls ()
return current_binding_level->names;
/* Return the list of type-tags (for structs, etc) of the current level. */
gettags ()
return current_binding_level->tags;
/* Store the list of declarations of the current level.
This is done for the parameter declarations of a function being defined,
after they are modified in the light of any missing parameters. */
static void
storedecls (decls)
tree decls;
current_binding_level->names = decls;
/* Similarly, store the list of tags of the current level. */
static void
storetags (tags)
tree tags;
current_binding_level->tags = tags;
return the structure (or union or enum) definition for that name.
Searches binding levels from BINDING_LEVEL up to the global level.
If THISLEVEL_ONLY is nonzero, searches only the specified context
(but skips any tag-transparent contexts to find one that is
meaningful for tags).
CODE says which kind of type the caller wants;
If the wrong kind of type is found, an error is reported. */
static tree
lookup_tag (code, name, binding_level, thislevel_only)
enum tree_code code;
struct binding_level *binding_level;
tree name;
int thislevel_only;
register struct binding_level *level;
for (level = binding_level; level; level = level->level_chain)
register tree tail;
for (tail = level->tags; tail; tail = TREE_CHAIN (tail))
if (TREE_PURPOSE (tail) == name)
if (TREE_CODE (TREE_VALUE (tail)) != code)
/* Definition isn't the kind we were looking for. */
pending_invalid_xref = name;
pending_invalid_xref_file = input_filename;
pending_invalid_xref_line = lineno;
return TREE_VALUE (tail);
if (thislevel_only && ! level->tag_transparent)
return NULL_TREE;
return NULL_TREE;
/* Print an error message now
for a recent invalid struct, union or enum cross reference.
We don't print them immediately because they are not invalid
when used in the `struct foo;' construct for shadowing. */
pending_xref_error ()
if (pending_invalid_xref != 0)
error_with_file_and_line (pending_invalid_xref_file,
"`%s' defined as wrong kind of tag",
IDENTIFIER_POINTER (pending_invalid_xref));
pending_invalid_xref = 0;
/* Given a type, find the tag that was defined for it and return the tag name.
Otherwise return 0. */
static tree
lookup_tag_reverse (type)
tree type;
register struct binding_level *level;
for (level = current_binding_level; level; level = level->level_chain)
register tree tail;
for (tail = level->tags; tail; tail = TREE_CHAIN (tail))
if (TREE_VALUE (tail) == type)
return TREE_PURPOSE (tail);
return NULL_TREE;
/* Look up NAME in the current binding level and its superiors
in the namespace of variables, functions and typedefs.
Return a ..._DECL node of some kind representing its definition,
or return 0 if it is undefined. */
lookup_name (name)
tree name;
register tree val;
if (current_binding_level != global_binding_level
return val;
/* Similar to `lookup_name' but look only at current binding level. */
lookup_name_current_level (name)
tree name;
register tree t;
if (current_binding_level == global_binding_level)
return 0;
for (t = current_binding_level->names; t; t = TREE_CHAIN (t))
if (DECL_NAME (t) == name)
return t;
/* Create the predefined scalar types of C,
and some nodes representing standard constants (0, 1, (void *) 0).
Initialize the global binding level.
Make definitions for built-in primitive functions. */
init_decl_processing ()
register tree endlink;
/* Either char* or void*. */
tree traditional_ptr_type_node;
/* Data types of memcpy and strlen. */
tree memcpy_ftype, memset_ftype, strlen_ftype;
tree void_ftype_any;
int wchar_type_size;
tree temp;
tree array_domain_type;
current_function_decl = NULL;
named_labels = NULL;
current_binding_level = NULL_BINDING_LEVEL;
free_binding_level = NULL_BINDING_LEVEL;
pushlevel (0); /* make the binding_level structure for global names */
global_binding_level = current_binding_level;
/* Define `int' and `char' first so that dbx will output them first. */
integer_type_node = make_signed_type (INT_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, ridpointers[(int) RID_INT],
/* Define `char', which is like either `signed char' or `unsigned char'
but not the same as either. */
= (flag_signed_char
? make_signed_type (CHAR_TYPE_SIZE)
: make_unsigned_type (CHAR_TYPE_SIZE));
pushdecl (build_decl (TYPE_DECL, get_identifier ("char"),
long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("long int"),
unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned int"),
long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("long unsigned int"),
long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("long long int"),
long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("long long unsigned int"),
short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("short int"),
short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("short unsigned int"),
/* `unsigned long' is the standard type for sizeof.
Traditionally, use a signed type.
Note that stddef.h uses `unsigned long',
and this must agree, even of long and int are the same size. */
if (flag_traditional && TREE_UNSIGNED (sizetype))
sizetype = signed_type (sizetype);
TREE_TYPE (TYPE_SIZE (integer_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (char_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (unsigned_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (long_unsigned_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (long_integer_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (long_long_integer_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (long_long_unsigned_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (short_integer_type_node)) = sizetype;
TREE_TYPE (TYPE_SIZE (short_unsigned_type_node)) = sizetype;
error_mark_node = make_node (ERROR_MARK);
TREE_TYPE (error_mark_node) = error_mark_node;
/* Define both `signed char' and `unsigned char'. */
signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("signed char"),
unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"),
intQI_type_node = make_signed_type (GET_MODE_BITSIZE (QImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, intQI_type_node));
intHI_type_node = make_signed_type (GET_MODE_BITSIZE (HImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, intHI_type_node));
intSI_type_node = make_signed_type (GET_MODE_BITSIZE (SImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, intSI_type_node));
intDI_type_node = make_signed_type (GET_MODE_BITSIZE (DImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, intDI_type_node));
unsigned_intQI_type_node = make_unsigned_type (GET_MODE_BITSIZE (QImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, unsigned_intQI_type_node));
unsigned_intHI_type_node = make_unsigned_type (GET_MODE_BITSIZE (HImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, unsigned_intHI_type_node));
unsigned_intSI_type_node = make_unsigned_type (GET_MODE_BITSIZE (SImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, unsigned_intSI_type_node));
unsigned_intDI_type_node = make_unsigned_type (GET_MODE_BITSIZE (DImode));
pushdecl (build_decl (TYPE_DECL, NULL_TREE, unsigned_intDI_type_node));
float_type_node = make_node (REAL_TYPE);
pushdecl (build_decl (TYPE_DECL, ridpointers[(int) RID_FLOAT],
layout_type (float_type_node);
double_type_node = make_node (REAL_TYPE);
if (flag_short_double)
TYPE_PRECISION (double_type_node) = FLOAT_TYPE_SIZE;
pushdecl (build_decl (TYPE_DECL, ridpointers[(int) RID_DOUBLE],
layout_type (double_type_node);
long_double_type_node = make_node (REAL_TYPE);
TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
pushdecl (build_decl (TYPE_DECL, get_identifier ("long double"),
layout_type (long_double_type_node);
complex_integer_type_node = make_node (COMPLEX_TYPE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("complex int"),
TREE_TYPE (complex_integer_type_node) = integer_type_node;
layout_type (complex_integer_type_node);
complex_float_type_node = make_node (COMPLEX_TYPE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("complex float"),
TREE_TYPE (complex_float_type_node) = float_type_node;
layout_type (complex_float_type_node);
complex_double_type_node = make_node (COMPLEX_TYPE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("complex double"),
TREE_TYPE (complex_double_type_node) = double_type_node;
layout_type (complex_double_type_node);
complex_long_double_type_node = make_node (COMPLEX_TYPE);
pushdecl (build_decl (TYPE_DECL, get_identifier ("complex long double"),
TREE_TYPE (complex_long_double_type_node) = long_double_type_node;
layout_type (complex_long_double_type_node);
wchar_type_size = TYPE_PRECISION (wchar_type_node);
signed_wchar_type_node = signed_type (wchar_type_node);
unsigned_wchar_type_node = unsigned_type (wchar_type_node);
integer_zero_node = build_int_2 (0, 0);
TREE_TYPE (integer_zero_node) = integer_type_node;
integer_one_node = build_int_2 (1, 0);
TREE_TYPE (integer_one_node) = integer_type_node;
boolean_type_node = integer_type_node;
boolean_true_node = integer_one_node;
boolean_false_node = integer_zero_node;
size_zero_node = build_int_2 (0, 0);
TREE_TYPE (size_zero_node) = sizetype;
size_one_node = build_int_2 (1, 0);
TREE_TYPE (size_one_node) = sizetype;
void_type_node = make_node (VOID_TYPE);
pushdecl (build_decl (TYPE_DECL,
ridpointers[(int) RID_VOID], void_type_node));
layout_type (void_type_node); /* Uses integer_zero_node */
/* We are not going to have real types in C with less than byte alignment,
so we might as well not have any types that claim to have it. */
TYPE_ALIGN (void_type_node) = BITS_PER_UNIT;
null_pointer_node = build_int_2 (0, 0);
TREE_TYPE (null_pointer_node) = build_pointer_type (void_type_node);
layout_type (TREE_TYPE (null_pointer_node));
string_type_node = build_pointer_type (char_type_node);
= build_pointer_type (build_type_variant (char_type_node, 1, 0));
/* Make a type to be the domain of a few array types
whose domains don't really matter.
200 is small enough that it always fits in size_t
and large enough that it can hold most function names for the
initializations of __FUNCTION__ and __PRETTY_FUNCTION__. */
array_domain_type = build_index_type (build_int_2 (200, 0));
/* make a type for arrays of characters.
With luck nothing will ever really depend on the length of this
array type. */
= build_array_type (char_type_node, array_domain_type);
/* Likewise for arrays of ints. */
= build_array_type (integer_type_node, array_domain_type);
/* This is for wide string constants. */
= build_array_type (wchar_type_node, array_domain_type);
= build_function_type (integer_type_node, NULL_TREE);
ptr_type_node = build_pointer_type (void_type_node);
= build_pointer_type (build_type_variant (void_type_node, 1, 0));
endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
= build_function_type (void_type_node, NULL_TREE);
= build_function_type (float_type_node,
tree_cons (NULL_TREE, float_type_node, endlink));
= build_function_type (double_type_node,
tree_cons (NULL_TREE, double_type_node, endlink));
= build_function_type (long_double_type_node,
tree_cons (NULL_TREE, long_double_type_node,
= build_function_type (double_type_node,
tree_cons (NULL_TREE, double_type_node,
tree_cons (NULL_TREE,
double_type_node, endlink)));
= build_function_type (integer_type_node,
tree_cons (NULL_TREE, integer_type_node, endlink));
= build_function_type (long_integer_type_node,
tree_cons (NULL_TREE,
long_integer_type_node, endlink));
= build_function_type (void_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE,
= build_function_type (integer_type_node,
tree_cons (NULL_TREE, const_ptr_type_node,
tree_cons (NULL_TREE, const_ptr_type_node,
tree_cons (NULL_TREE,
= build_function_type (void_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE, integer_type_node,
tree_cons (NULL_TREE,
string_ftype_ptr_ptr /* strcpy prototype */
= build_function_type (string_type_node,
tree_cons (NULL_TREE, string_type_node,
tree_cons (NULL_TREE,
int_ftype_string_string /* strcmp prototype */
= build_function_type (integer_type_node,
tree_cons (NULL_TREE, const_string_type_node,
tree_cons (NULL_TREE,
strlen_ftype /* strlen prototype */
= build_function_type (flag_traditional ? integer_type_node : sizetype,
tree_cons (NULL_TREE, const_string_type_node,
= (flag_traditional ? string_type_node : ptr_type_node);
memcpy_ftype /* memcpy prototype */
= build_function_type (traditional_ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE, const_ptr_type_node,
tree_cons (NULL_TREE,
memset_ftype /* memset prototype */
= build_function_type (traditional_ptr_type_node,
tree_cons (NULL_TREE, ptr_type_node,
tree_cons (NULL_TREE, integer_type_node,
tree_cons (NULL_TREE,
builtin_function ("__builtin_constant_p", default_function_type,
builtin_function ("__builtin_return_address",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE,
builtin_function ("__builtin_frame_address",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE,
builtin_function ("__builtin_aggregate_incoming_address",
build_function_type (ptr_type_node, NULL_TREE),
builtin_function ("__builtin_alloca",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE,
BUILT_IN_ALLOCA, "alloca");
builtin_function ("__builtin_ffs", int_ftype_int, BUILT_IN_FFS, NULL_PTR);
/* Define alloca, ffs as builtins.
Declare _exit just to mark it as volatile. */
if (! flag_no_builtin && !flag_no_nonansi_builtin)
temp = builtin_function ("alloca",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE,
/* Suppress error if redefined as a non-function. */
temp = builtin_function ("ffs", int_ftype_int, BUILT_IN_FFS, NULL_PTR);
/* Suppress error if redefined as a non-function. */
temp = builtin_function ("_exit", void_ftype_any, NOT_BUILT_IN,
/* Suppress error if redefined as a non-function. */
builtin_function ("__builtin_abs", int_ftype_int, BUILT_IN_ABS, NULL_PTR);
builtin_function ("__builtin_fabsf", float_ftype_float, BUILT_IN_FABS,
builtin_function ("__builtin_fabs", double_ftype_double, BUILT_IN_FABS,
builtin_function ("__builtin_fabsl", ldouble_ftype_ldouble, BUILT_IN_FABS,
builtin_function ("__builtin_labs", long_ftype_long, BUILT_IN_LABS,
builtin_function ("__builtin_saveregs",
build_function_type (ptr_type_node, NULL_TREE),
/* EXPAND_BUILTIN_VARARGS is obsolete. */
#if 0
builtin_function ("__builtin_varargs",
build_function_type (ptr_type_node,
tree_cons (NULL_TREE,
builtin_function ("__builtin_classify_type", default_function_type,
builtin_function ("__builtin_next_arg",
build_function_type (ptr_type_node, NULL_TREE),
builtin_function ("__builtin_args_info",