alistair23-linux/scripts/genksyms/parse.y
Andreas Gruenbacher 94aa3d716e kbuild: genksyms parser: fix the __attribute__ rule
We are having two kinds of problems with genksyms today: fake checksum
changes without actual ABI changes, and changes which we would rather like
to ignore (such as an additional field at the end of a structure that
modules are not supposed to touch, for example).

I have thought about ways to improve genksyms and compute checksums
differently to avoid those problems, but in the end I don't see a
fundamentally better way.  So here are some genksyms patches for at least
making the checksums more easily manageable, if we cannot fully fix them.

In addition to the bugfixes (the first two patches), this allows genksyms
to track checksum changes and report why a checksum changed (third patch),
and to selectively ignore changes (fourth patch).

This patch:

Gcc __attribute__ definitions may occur repeatedly, e.g.,

	static int foo __attribute__((__used__))
		       __attribute__((aligned (16)));

The genksyms parser does not understand this, and generates a syntax error.
Fix this case.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-07-31 23:00:25 +02:00

474 lines
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/* C global declaration parser for genksyms.
Copyright 1996, 1997 Linux International.
New implementation contributed by Richard Henderson <rth@tamu.edu>
Based on original work by Bjorn Ekwall <bj0rn@blox.se>
This file is part of the Linux modutils.
This program 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 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
%{
#include <assert.h>
#include <malloc.h>
#include "genksyms.h"
static int is_typedef;
static int is_extern;
static char *current_name;
static struct string_list *decl_spec;
static void yyerror(const char *);
static inline void
remove_node(struct string_list **p)
{
struct string_list *node = *p;
*p = node->next;
free_node(node);
}
static inline void
remove_list(struct string_list **pb, struct string_list **pe)
{
struct string_list *b = *pb, *e = *pe;
*pb = e;
free_list(b, e);
}
%}
%token ASM_KEYW
%token ATTRIBUTE_KEYW
%token AUTO_KEYW
%token BOOL_KEYW
%token CHAR_KEYW
%token CONST_KEYW
%token DOUBLE_KEYW
%token ENUM_KEYW
%token EXTERN_KEYW
%token EXTENSION_KEYW
%token FLOAT_KEYW
%token INLINE_KEYW
%token INT_KEYW
%token LONG_KEYW
%token REGISTER_KEYW
%token RESTRICT_KEYW
%token SHORT_KEYW
%token SIGNED_KEYW
%token STATIC_KEYW
%token STRUCT_KEYW
%token TYPEDEF_KEYW
%token UNION_KEYW
%token UNSIGNED_KEYW
%token VOID_KEYW
%token VOLATILE_KEYW
%token TYPEOF_KEYW
%token EXPORT_SYMBOL_KEYW
%token ASM_PHRASE
%token ATTRIBUTE_PHRASE
%token BRACE_PHRASE
%token BRACKET_PHRASE
%token EXPRESSION_PHRASE
%token CHAR
%token DOTS
%token IDENT
%token INT
%token REAL
%token STRING
%token TYPE
%token OTHER
%token FILENAME
%%
declaration_seq:
declaration
| declaration_seq declaration
;
declaration:
{ is_typedef = 0; is_extern = 0; current_name = NULL; decl_spec = NULL; }
declaration1
{ free_list(*$2, NULL); *$2 = NULL; }
;
declaration1:
EXTENSION_KEYW TYPEDEF_KEYW { is_typedef = 1; } simple_declaration
{ $$ = $4; }
| TYPEDEF_KEYW { is_typedef = 1; } simple_declaration
{ $$ = $3; }
| simple_declaration
| function_definition
| asm_definition
| export_definition
| error ';' { $$ = $2; }
| error '}' { $$ = $2; }
;
simple_declaration:
decl_specifier_seq_opt init_declarator_list_opt ';'
{ if (current_name) {
struct string_list *decl = (*$3)->next;
(*$3)->next = NULL;
add_symbol(current_name,
is_typedef ? SYM_TYPEDEF : SYM_NORMAL,
decl, is_extern);
current_name = NULL;
}
$$ = $3;
}
;
init_declarator_list_opt:
/* empty */ { $$ = NULL; }
| init_declarator_list
;
init_declarator_list:
init_declarator
{ struct string_list *decl = *$1;
*$1 = NULL;
add_symbol(current_name,
is_typedef ? SYM_TYPEDEF : SYM_NORMAL, decl, is_extern);
current_name = NULL;
$$ = $1;
}
| init_declarator_list ',' init_declarator
{ struct string_list *decl = *$3;
*$3 = NULL;
free_list(*$2, NULL);
*$2 = decl_spec;
add_symbol(current_name,
is_typedef ? SYM_TYPEDEF : SYM_NORMAL, decl, is_extern);
current_name = NULL;
$$ = $3;
}
;
init_declarator:
declarator asm_phrase_opt attribute_opt initializer_opt
{ $$ = $4 ? $4 : $3 ? $3 : $2 ? $2 : $1; }
;
/* Hang on to the specifiers so that we can reuse them. */
decl_specifier_seq_opt:
/* empty */ { decl_spec = NULL; }
| decl_specifier_seq
;
decl_specifier_seq:
decl_specifier { decl_spec = *$1; }
| decl_specifier_seq decl_specifier { decl_spec = *$2; }
;
decl_specifier:
storage_class_specifier
{ /* Version 2 checksumming ignores storage class, as that
is really irrelevant to the linkage. */
remove_node($1);
$$ = $1;
}
| type_specifier
;
storage_class_specifier:
AUTO_KEYW
| REGISTER_KEYW
| STATIC_KEYW
| EXTERN_KEYW { is_extern = 1; $$ = $1; }
| INLINE_KEYW { is_extern = 0; $$ = $1; }
;
type_specifier:
simple_type_specifier
| cvar_qualifier
| TYPEOF_KEYW '(' decl_specifier_seq '*' ')'
| TYPEOF_KEYW '(' decl_specifier_seq ')'
/* References to s/u/e's defined elsewhere. Rearrange things
so that it is easier to expand the definition fully later. */
| STRUCT_KEYW IDENT
{ remove_node($1); (*$2)->tag = SYM_STRUCT; $$ = $2; }
| UNION_KEYW IDENT
{ remove_node($1); (*$2)->tag = SYM_UNION; $$ = $2; }
| ENUM_KEYW IDENT
{ remove_node($1); (*$2)->tag = SYM_ENUM; $$ = $2; }
/* Full definitions of an s/u/e. Record it. */
| STRUCT_KEYW IDENT class_body
{ struct string_list *s = *$3, *i = *$2, *r;
r = copy_node(i); r->tag = SYM_STRUCT;
r->next = (*$1)->next; *$3 = r; (*$1)->next = NULL;
add_symbol(i->string, SYM_STRUCT, s, is_extern);
$$ = $3;
}
| UNION_KEYW IDENT class_body
{ struct string_list *s = *$3, *i = *$2, *r;
r = copy_node(i); r->tag = SYM_UNION;
r->next = (*$1)->next; *$3 = r; (*$1)->next = NULL;
add_symbol(i->string, SYM_UNION, s, is_extern);
$$ = $3;
}
| ENUM_KEYW IDENT BRACE_PHRASE
{ struct string_list *s = *$3, *i = *$2, *r;
r = copy_node(i); r->tag = SYM_ENUM;
r->next = (*$1)->next; *$3 = r; (*$1)->next = NULL;
add_symbol(i->string, SYM_ENUM, s, is_extern);
$$ = $3;
}
/* Anonymous s/u/e definitions. Nothing needs doing. */
| ENUM_KEYW BRACE_PHRASE { $$ = $2; }
| STRUCT_KEYW class_body { $$ = $2; }
| UNION_KEYW class_body { $$ = $2; }
;
simple_type_specifier:
CHAR_KEYW
| SHORT_KEYW
| INT_KEYW
| LONG_KEYW
| SIGNED_KEYW
| UNSIGNED_KEYW
| FLOAT_KEYW
| DOUBLE_KEYW
| VOID_KEYW
| BOOL_KEYW
| TYPE { (*$1)->tag = SYM_TYPEDEF; $$ = $1; }
;
ptr_operator:
'*' cvar_qualifier_seq_opt
{ $$ = $2 ? $2 : $1; }
;
cvar_qualifier_seq_opt:
/* empty */ { $$ = NULL; }
| cvar_qualifier_seq
;
cvar_qualifier_seq:
cvar_qualifier
| cvar_qualifier_seq cvar_qualifier { $$ = $2; }
;
cvar_qualifier:
CONST_KEYW | VOLATILE_KEYW | ATTRIBUTE_PHRASE
| RESTRICT_KEYW
{ /* restrict has no effect in prototypes so ignore it */
remove_node($1);
$$ = $1;
}
;
declarator:
ptr_operator declarator { $$ = $2; }
| direct_declarator
;
direct_declarator:
IDENT
{ if (current_name != NULL) {
error_with_pos("unexpected second declaration name");
YYERROR;
} else {
current_name = (*$1)->string;
$$ = $1;
}
}
| direct_declarator '(' parameter_declaration_clause ')'
{ $$ = $4; }
| direct_declarator '(' error ')'
{ $$ = $4; }
| direct_declarator BRACKET_PHRASE
{ $$ = $2; }
| '(' declarator ')'
{ $$ = $3; }
| '(' error ')'
{ $$ = $3; }
;
/* Nested declarators differ from regular declarators in that they do
not record the symbols they find in the global symbol table. */
nested_declarator:
ptr_operator nested_declarator { $$ = $2; }
| direct_nested_declarator
;
direct_nested_declarator:
IDENT
| TYPE
| direct_nested_declarator '(' parameter_declaration_clause ')'
{ $$ = $4; }
| direct_nested_declarator '(' error ')'
{ $$ = $4; }
| direct_nested_declarator BRACKET_PHRASE
{ $$ = $2; }
| '(' nested_declarator ')'
{ $$ = $3; }
| '(' error ')'
{ $$ = $3; }
;
parameter_declaration_clause:
parameter_declaration_list_opt DOTS { $$ = $2; }
| parameter_declaration_list_opt
| parameter_declaration_list ',' DOTS { $$ = $3; }
;
parameter_declaration_list_opt:
/* empty */ { $$ = NULL; }
| parameter_declaration_list
;
parameter_declaration_list:
parameter_declaration
| parameter_declaration_list ',' parameter_declaration
{ $$ = $3; }
;
parameter_declaration:
decl_specifier_seq m_abstract_declarator
{ $$ = $2 ? $2 : $1; }
;
m_abstract_declarator:
ptr_operator m_abstract_declarator
{ $$ = $2 ? $2 : $1; }
| direct_m_abstract_declarator
;
direct_m_abstract_declarator:
/* empty */ { $$ = NULL; }
| IDENT
{ /* For version 2 checksums, we don't want to remember
private parameter names. */
remove_node($1);
$$ = $1;
}
/* This wasn't really a typedef name but an identifier that
shadows one. */
| TYPE
{ remove_node($1);
$$ = $1;
}
| direct_m_abstract_declarator '(' parameter_declaration_clause ')'
{ $$ = $4; }
| direct_m_abstract_declarator '(' error ')'
{ $$ = $4; }
| direct_m_abstract_declarator BRACKET_PHRASE
{ $$ = $2; }
| '(' m_abstract_declarator ')'
{ $$ = $3; }
| '(' error ')'
{ $$ = $3; }
;
function_definition:
decl_specifier_seq_opt declarator BRACE_PHRASE
{ struct string_list *decl = *$2;
*$2 = NULL;
add_symbol(current_name, SYM_NORMAL, decl, is_extern);
$$ = $3;
}
;
initializer_opt:
/* empty */ { $$ = NULL; }
| initializer
;
/* We never care about the contents of an initializer. */
initializer:
'=' EXPRESSION_PHRASE
{ remove_list($2, &(*$1)->next); $$ = $2; }
;
class_body:
'{' member_specification_opt '}' { $$ = $3; }
| '{' error '}' { $$ = $3; }
;
member_specification_opt:
/* empty */ { $$ = NULL; }
| member_specification
;
member_specification:
member_declaration
| member_specification member_declaration { $$ = $2; }
;
member_declaration:
decl_specifier_seq_opt member_declarator_list_opt ';'
{ $$ = $3; }
| error ';'
{ $$ = $2; }
;
member_declarator_list_opt:
/* empty */ { $$ = NULL; }
| member_declarator_list
;
member_declarator_list:
member_declarator
| member_declarator_list ',' member_declarator { $$ = $3; }
;
member_declarator:
nested_declarator attribute_opt { $$ = $2 ? $2 : $1; }
| IDENT member_bitfield_declarator { $$ = $2; }
| member_bitfield_declarator
;
member_bitfield_declarator:
':' EXPRESSION_PHRASE { $$ = $2; }
;
attribute_opt:
/* empty */ { $$ = NULL; }
| attribute_opt ATTRIBUTE_PHRASE
;
asm_definition:
ASM_PHRASE ';' { $$ = $2; }
;
asm_phrase_opt:
/* empty */ { $$ = NULL; }
| ASM_PHRASE
;
export_definition:
EXPORT_SYMBOL_KEYW '(' IDENT ')' ';'
{ export_symbol((*$3)->string); $$ = $5; }
;
%%
static void
yyerror(const char *e)
{
error_with_pos("%s", e);
}