2d9db28e7a
* c-pragma.c (handle_pragma_token): Test for null tree before dereferencing TREE_CODE. From-SVN: r23104
453 lines
9.9 KiB
C
453 lines
9.9 KiB
C
/* Handle #pragma, system V.4 style. Supports #pragma weak and #pragma pack.
|
||
Copyright (C) 1992, 1997, 1998 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
|
||
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 GNU CC; see the file COPYING. If not, write to
|
||
the Free Software Foundation, 59 Temple Place - Suite 330,
|
||
Boston, MA 02111-1307, USA. */
|
||
|
||
#include "config.h"
|
||
#include "system.h"
|
||
#include "rtl.h"
|
||
#include "tree.h"
|
||
#include "except.h"
|
||
#include "function.h"
|
||
#include "defaults.h"
|
||
#include "c-pragma.h"
|
||
#include "flags.h"
|
||
#include "toplev.h"
|
||
|
||
#ifdef HANDLE_GENERIC_PRAGMAS
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK
|
||
/* When structure field packing is in effect, this variable is the
|
||
number of bits to use as the maximum alignment. When packing is not
|
||
in effect, this is zero. */
|
||
|
||
extern int maximum_field_alignment;
|
||
#endif
|
||
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
|
||
typedef struct align_stack
|
||
{
|
||
int alignment;
|
||
unsigned int num_pushes;
|
||
struct align_stack * prev;
|
||
} align_stack;
|
||
|
||
static struct align_stack * alignment_stack = NULL;
|
||
|
||
static int push_alignment PROTO((int));
|
||
static int pop_alignment PROTO((void));
|
||
|
||
/* Push an alignment value onto the stack. */
|
||
static int
|
||
push_alignment (alignment)
|
||
int alignment;
|
||
{
|
||
switch (alignment)
|
||
{
|
||
case 0:
|
||
case 1:
|
||
case 2:
|
||
case 4:
|
||
case 8:
|
||
case 16:
|
||
break;
|
||
default:
|
||
warning ("\
|
||
Alignment must be a small power of two, not %d, in #pragma pack",
|
||
alignment);
|
||
return 0;
|
||
}
|
||
|
||
if (alignment_stack == NULL
|
||
|| alignment_stack->alignment != alignment)
|
||
{
|
||
align_stack * entry;
|
||
|
||
entry = (align_stack *) xmalloc (sizeof (* entry));
|
||
|
||
if (entry == NULL)
|
||
{
|
||
warning ("Out of memory pushing #pragma pack");
|
||
return 0;
|
||
}
|
||
|
||
entry->alignment = alignment;
|
||
entry->num_pushes = 1;
|
||
entry->prev = alignment_stack;
|
||
|
||
alignment_stack = entry;
|
||
|
||
if (alignment < 8)
|
||
maximum_field_alignment = alignment * 8;
|
||
else
|
||
/* MSVC ignores alignments > 4. */
|
||
maximum_field_alignment = 0;
|
||
}
|
||
else
|
||
alignment_stack->num_pushes ++;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Undo a push of an alignment onto the stack. */
|
||
static int
|
||
pop_alignment ()
|
||
{
|
||
if (alignment_stack == NULL)
|
||
{
|
||
warning ("\
|
||
#pragma pack(pop) encountered without corresponding #pragma pack(push,<n>)");
|
||
return 0;
|
||
}
|
||
|
||
if (-- alignment_stack->num_pushes == 0)
|
||
{
|
||
align_stack * entry;
|
||
|
||
entry = alignment_stack->prev;
|
||
|
||
if (entry == NULL || entry->alignment > 4)
|
||
maximum_field_alignment = 0;
|
||
else
|
||
maximum_field_alignment = entry->alignment * 8;
|
||
|
||
free (alignment_stack);
|
||
|
||
alignment_stack = entry;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Generate 'packed' and 'aligned' attributes for decls whilst a
|
||
#pragma pack(push... is in effect. */
|
||
void
|
||
insert_pack_attributes (node, attributes, prefix)
|
||
tree node;
|
||
tree * attributes;
|
||
tree * prefix;
|
||
{
|
||
tree a;
|
||
|
||
/* If we are not packing, then there is nothing to do. */
|
||
if (maximum_field_alignment == 0
|
||
|| alignment_stack == NULL)
|
||
return;
|
||
|
||
/* We are only interested in fields. */
|
||
if (TREE_CODE_CLASS (TREE_CODE (node)) != 'd'
|
||
|| TREE_CODE (node) != FIELD_DECL)
|
||
return;
|
||
|
||
/* Add a 'packed' attribute. */
|
||
* attributes = tree_cons (get_identifier ("packed"), NULL, * attributes);
|
||
|
||
/* If the alignment is > 8 then add an alignment attribute as well. */
|
||
if (maximum_field_alignment > 8)
|
||
{
|
||
/* If the aligned attribute is already present then do not override it. */
|
||
for (a = * attributes; a; a = TREE_CHAIN (a))
|
||
{
|
||
tree name = TREE_PURPOSE (a);
|
||
if (strcmp (IDENTIFIER_POINTER (name), "aligned") == 0)
|
||
break;
|
||
}
|
||
|
||
if (a == NULL)
|
||
for (a = * prefix; a; a = TREE_CHAIN (a))
|
||
{
|
||
tree name = TREE_PURPOSE (a);
|
||
if (strcmp (IDENTIFIER_POINTER (name), "aligned") == 0)
|
||
break;
|
||
}
|
||
|
||
if (a == NULL)
|
||
{
|
||
* attributes = tree_cons
|
||
(get_identifier ("aligned"),
|
||
tree_cons (NULL,
|
||
build_int_2 (maximum_field_alignment / 8, 0),
|
||
NULL),
|
||
* attributes);
|
||
}
|
||
}
|
||
|
||
return;
|
||
}
|
||
#endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
|
||
|
||
#ifdef HANDLE_PRAGMA_WEAK
|
||
static int add_weak PROTO((char *, char *));
|
||
|
||
static int
|
||
add_weak (name, value)
|
||
char * name;
|
||
char * value;
|
||
{
|
||
struct weak_syms * weak;
|
||
|
||
weak = (struct weak_syms *) permalloc (sizeof (struct weak_syms));
|
||
|
||
if (weak == NULL)
|
||
return 0;
|
||
|
||
weak->next = weak_decls;
|
||
weak->name = name;
|
||
weak->value = value;
|
||
weak_decls = weak;
|
||
|
||
return 1;
|
||
}
|
||
#endif /* HANDLE_PRAGMA_WEAK */
|
||
|
||
/* Handle one token of a pragma directive. TOKEN is the current token, and
|
||
STRING is its printable form. Some front ends do not support generating
|
||
tokens, and will only pass in a STRING. Also some front ends will reuse
|
||
the buffer containing STRING, so it must be copied to a local buffer if
|
||
it needs to be preserved.
|
||
|
||
If STRING is non-NULL, then the return value will be ignored, and there
|
||
will be futher calls to handle_pragma_token() in order to handle the rest of
|
||
the line containing the #pragma directive. If STRING is NULL, the entire
|
||
line has now been presented to handle_pragma_token() and the return value
|
||
should be zero if the pragma flawed in some way, or if the pragma was not
|
||
recognised, and non-zero if it was successfully handled. */
|
||
|
||
int
|
||
handle_pragma_token (string, token)
|
||
char * string;
|
||
tree token;
|
||
{
|
||
static enum pragma_state state = ps_start;
|
||
static enum pragma_state type;
|
||
static char * name;
|
||
static char * value;
|
||
static int align;
|
||
|
||
/* If we have reached the end of the #pragma directive then
|
||
determine what value we should return. */
|
||
|
||
if (string == NULL)
|
||
{
|
||
int ret_val = 0;
|
||
|
||
switch (type)
|
||
{
|
||
default:
|
||
abort ();
|
||
break;
|
||
|
||
case ps_done:
|
||
/* The pragma was not recognised. */
|
||
break;
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK
|
||
case ps_pack:
|
||
if (state == ps_right)
|
||
{
|
||
maximum_field_alignment = align * 8;
|
||
ret_val = 1;
|
||
}
|
||
else
|
||
warning ("malformed `#pragma pack'");
|
||
break;
|
||
#endif /* HANDLE_PRAGMA_PACK */
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
|
||
case ps_push:
|
||
if (state == ps_right)
|
||
ret_val = push_alignment (align);
|
||
else
|
||
warning ("incomplete '#pragma pack(push,<n>)'");
|
||
break;
|
||
|
||
case ps_pop:
|
||
if (state == ps_right)
|
||
ret_val = pop_alignment ();
|
||
else
|
||
warning ("missing closing parenthesis in '#pragma pack(pop)'");
|
||
break;
|
||
#endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
|
||
|
||
#ifdef HANDLE_PRAGMA_WEAK
|
||
case ps_weak:
|
||
if (HANDLE_PRAGMA_WEAK)
|
||
{
|
||
if (state == ps_name)
|
||
ret_val = add_weak (name, NULL);
|
||
else if (state == ps_value)
|
||
ret_val = add_weak (name, value);
|
||
else
|
||
warning ("malformed `#pragma weak'");
|
||
}
|
||
else
|
||
ret_val = 1; /* Ignore the pragma. */
|
||
break;
|
||
#endif /* HANDLE_PRAGMA_WEAK */
|
||
}
|
||
|
||
type = state = ps_start;
|
||
|
||
return ret_val;
|
||
}
|
||
|
||
/* If we have been given a token, but it is not an identifier,
|
||
or a small constant, then something has gone wrong. */
|
||
if (token)
|
||
{
|
||
switch (TREE_CODE (token))
|
||
{
|
||
case IDENTIFIER_NODE:
|
||
break;
|
||
|
||
case INTEGER_CST:
|
||
if (TREE_INT_CST_HIGH (token) != 0)
|
||
return 0;
|
||
break;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
switch (state)
|
||
{
|
||
case ps_start:
|
||
type = state = ps_done;
|
||
#ifdef HANDLE_PRAGMA_PACK
|
||
if (strcmp (string, "pack") == 0)
|
||
type = state = ps_pack;
|
||
#endif
|
||
#ifdef HANDLE_PRAGMA_WEAK
|
||
if (strcmp (string, "weak") == 0)
|
||
type = state = ps_weak;
|
||
#endif
|
||
break;
|
||
|
||
#ifdef HANDLE_PRAGMA_WEAK
|
||
case ps_weak:
|
||
name = permalloc (strlen (string) + 1);
|
||
if (name == NULL)
|
||
{
|
||
warning ("Out of memory parsing #pragma weak");
|
||
state = ps_bad;
|
||
}
|
||
else
|
||
{
|
||
strcpy (name, string);
|
||
state = ps_name;
|
||
}
|
||
break;
|
||
|
||
case ps_name:
|
||
state = (strcmp (string, "=") ? ps_bad : ps_equals);
|
||
break;
|
||
|
||
case ps_equals:
|
||
value = permalloc (strlen (string) + 1);
|
||
if (value == NULL)
|
||
{
|
||
warning ("Out of memory parsing #pragma weak");
|
||
state = ps_bad;
|
||
}
|
||
else
|
||
{
|
||
strcpy (value, string);
|
||
state = ps_value;
|
||
}
|
||
break;
|
||
|
||
case ps_value:
|
||
state = ps_bad;
|
||
break;
|
||
#endif /* HANDLE_PRAGMA_WEAK */
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK
|
||
case ps_pack:
|
||
state = (strcmp (string, "(") ? ps_bad : ps_left);
|
||
break;
|
||
|
||
case ps_left:
|
||
|
||
if (token && TREE_CODE(token) == INTEGER_CST)
|
||
align = TREE_INT_CST_LOW(token);
|
||
else
|
||
align = atoi (string);
|
||
switch (align)
|
||
{
|
||
case 1:
|
||
case 2:
|
||
case 4:
|
||
state = ps_align;
|
||
break;
|
||
|
||
case 0:
|
||
state = (strcmp (string, ")") ? ps_bad : ps_right);
|
||
#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
|
||
if (state == ps_bad)
|
||
{
|
||
if (strcmp (string, "push") == 0)
|
||
type = state = ps_push;
|
||
else if (strcmp (string, "pop") == 0)
|
||
type = state = ps_pop;
|
||
}
|
||
#endif
|
||
break;
|
||
|
||
default:
|
||
state = ps_bad;
|
||
break;
|
||
}
|
||
break;
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
|
||
case ps_pop:
|
||
#endif
|
||
case ps_align:
|
||
state = (strcmp (string, ")") ? ps_bad : ps_right);
|
||
break;
|
||
|
||
case ps_right:
|
||
state = ps_bad;
|
||
break;
|
||
#endif /* HANDLE_PRAGMA_PACK */
|
||
|
||
#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
|
||
case ps_push:
|
||
state = (strcmp (string, ",") ? ps_bad : ps_comma);
|
||
break;
|
||
|
||
case ps_comma:
|
||
align = atoi (string);
|
||
state = ps_align;
|
||
break;
|
||
#endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
|
||
|
||
case ps_bad:
|
||
case ps_done:
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
#endif /* HANDLE_GENERIC_PRAGMAS */
|