/* Handle #pragma, system V.4 style. Supports #pragma weak and #pragma pack.
- Copyright (C) 1992, 1997, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1992, 1997, 1998, 1999, 2000, 2001
+ Free Software Foundation, Inc.
This file is part of GNU CC.
#include "system.h"
#include "rtl.h"
#include "tree.h"
-#include "except.h"
#include "function.h"
-#include "defaults.h"
+#include "cpplib.h"
#include "c-pragma.h"
#include "flags.h"
#include "toplev.h"
+#include "ggc.h"
+#include "c-lex.h"
+#include "tm_p.h"
-#ifdef HANDLE_GENERIC_PRAGMAS
+#define BAD(msgid) do { warning (msgid); return; } while (0)
+#define BAD2(msgid, arg) do { warning (msgid, arg); return; } while (0)
#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
-
+static void handle_pragma_pack PARAMS ((cpp_reader *));
#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
typedef struct align_stack
{
int alignment;
unsigned int num_pushes;
+ tree id;
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));
+/* If we have a "global" #pragma pack(<n>) in effect when the first
+ #pragma pack(push,<n>) is encountered, this stores the value of
+ maximum_field_alignment in effect. When the final pop_alignment()
+ happens, we restore the value to this, not to a value of 0 for
+ maximum_field_alignment. Value is in bits. */
+static int default_alignment;
+#define SET_GLOBAL_ALIGNMENT(ALIGN) \
+(default_alignment = maximum_field_alignment = (ALIGN))
+
+static void push_alignment PARAMS ((int, tree));
+static void pop_alignment PARAMS ((tree));
+static void mark_align_stack PARAMS ((void *));
/* Push an alignment value onto the stack. */
-static int
-push_alignment (alignment)
+static void
+push_alignment (alignment, id)
int alignment;
+ tree id;
{
- 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)
+ || alignment_stack->alignment != alignment
+ || id != NULL_TREE)
{
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->id = id;
entry->prev = alignment_stack;
+ /* The current value of maximum_field_alignment is not necessarily
+ 0 since there may be a #pragma pack(<n>) in effect; remember it
+ so that we can restore it after the final #pragma pop(). */
+ if (alignment_stack == NULL)
+ default_alignment = maximum_field_alignment;
+
alignment_stack = entry;
- if (alignment < 8)
- maximum_field_alignment = alignment * 8;
- else
- /* MSVC ignores alignments > 4. */
- maximum_field_alignment = 0;
+ maximum_field_alignment = alignment;
}
else
alignment_stack->num_pushes ++;
-
- return 1;
}
/* Undo a push of an alignment onto the stack. */
-static int
-pop_alignment ()
+static void
+pop_alignment (id)
+ tree id;
{
+ align_stack * entry;
+
if (alignment_stack == NULL)
{
warning ("\
-#pragma pack(pop) encountered without corresponding #pragma pack(push,<n>)");
- return 0;
+#pragma pack (pop) encountered without matching #pragma pack (push, <n>)"
+ );
+ return;
+ }
+
+ /* If we got an identifier, strip away everything above the target
+ entry so that the next step will restore the state just below it. */
+ if (id)
+ {
+ for (entry = alignment_stack; entry; entry = entry->prev)
+ if (entry->id == id)
+ {
+ entry->num_pushes = 1;
+ alignment_stack = entry;
+ break;
+ }
+ if (entry == NULL)
+ warning ("\
+#pragma pack(pop, %s) encountered without matching #pragma pack(push, %s, <n>)"
+ , IDENTIFIER_POINTER (id), IDENTIFIER_POINTER (id));
}
if (-- alignment_stack->num_pushes == 0)
{
- align_stack * entry;
-
entry = alignment_stack->prev;
- if (entry == NULL || entry->alignment > 4)
- maximum_field_alignment = 0;
+ if (entry == NULL)
+ maximum_field_alignment = default_alignment;
else
- maximum_field_alignment = entry->alignment * 8;
+ maximum_field_alignment = entry->alignment;
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;
+static void
+mark_align_stack (p)
+ void *p;
{
- tree a;
+ align_stack *a = *(align_stack **) p;
- /* 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)
+ while (a)
{
- /* 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);
- }
+ ggc_mark_tree (a->id);
+ a = a->prev;
}
-
- return;
}
+#else /* not HANDLE_PRAGMA_PACK_PUSH_POP */
+#define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = (ALIGN))
+#define push_alignment(ID, N) \
+ BAD("#pragma pack(push[, id], <n>) is not supported on this target")
+#define pop_alignment(ID) \
+ BAD("#pragma pack(pop[, id], <n>) is not supported on this target")
#endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
-\f
-#ifdef HANDLE_PRAGMA_WEAK
-static int add_weak PROTO((char *, char *));
-static int
-add_weak (name, value)
- char * name;
- char * value;
+/* #pragma pack ()
+ #pragma pack (N)
+
+ #pragma pack (push, N)
+ #pragma pack (push, ID, N)
+ #pragma pack (pop)
+ #pragma pack (pop, ID) */
+static void
+handle_pragma_pack (dummy)
+ cpp_reader *dummy ATTRIBUTE_UNUSED;
{
- struct weak_syms * weak;
+ tree x, id = 0;
+ int align = -1;
+ enum cpp_ttype token;
+ enum { set, push, pop } action;
- weak = (struct weak_syms *) permalloc (sizeof (struct weak_syms));
+ if (c_lex (&x) != CPP_OPEN_PAREN)
+ BAD ("missing '(' after '#pragma pack' - ignored");
- if (weak == NULL)
- return 0;
-
- weak->next = weak_decls;
- weak->name = name;
- weak->value = value;
- weak_decls = weak;
-
- return 1;
-}
-#endif /* HANDLE_PRAGMA_WEAK */
-\f
-/* 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)
+ token = c_lex (&x);
+ if (token == CPP_CLOSE_PAREN)
+ {
+ action = set;
+ align = 0;
+ }
+ else if (token == CPP_NUMBER)
{
- int ret_val = 0;
+ align = TREE_INT_CST_LOW (x);
+ action = set;
+ if (c_lex (&x) != CPP_CLOSE_PAREN)
+ BAD ("malformed '#pragma pack' - ignored");
+ }
+ else if (token == CPP_NAME)
+ {
+#define BAD_ACTION do { if (action == push) \
+ BAD ("malformed '#pragma pack(push[, id], <n>)' - ignored"); \
+ else \
+ BAD ("malformed '#pragma pack(pop[, id])' - ignored"); \
+ } while (0)
+
+ const char *op = IDENTIFIER_POINTER (x);
+ if (!strcmp (op, "push"))
+ action = push;
+ else if (!strcmp (op, "pop"))
+ action = pop;
+ else
+ BAD2 ("unknown action '%s' for '#pragma pack' - ignored", op);
- switch (type)
+ token = c_lex (&x);
+ if (token != CPP_COMMA && action == push)
+ BAD_ACTION;
+
+ if (token == CPP_COMMA)
{
- default:
- abort ();
- break;
-
- case ps_done:
- /* The pragma was not recognised. */
- break;
-
-#ifdef HANDLE_PRAGMA_PACK
- case ps_pack:
- if (state == ps_right)
+ token = c_lex (&x);
+ if (token == CPP_NAME)
{
- maximum_field_alignment = align * 8;
- ret_val = 1;
+ id = x;
+ if (action == push && c_lex (&x) != CPP_COMMA)
+ BAD_ACTION;
+ token = c_lex (&x);
}
- 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 (action == push)
{
- if (state == ps_name)
- ret_val = add_weak (name, NULL);
- else if (state == ps_value)
- ret_val = add_weak (name, value);
+ if (token == CPP_NUMBER)
+ {
+ align = TREE_INT_CST_LOW (x);
+ token = c_lex (&x);
+ }
else
- warning ("malformed `#pragma weak'");
+ BAD_ACTION;
}
- else
- ret_val = 1; /* Ignore the pragma. */
- break;
-#endif /* HANDLE_PRAGMA_WEAK */
}
- type = state = ps_start;
-
- return ret_val;
+ if (token != CPP_CLOSE_PAREN)
+ BAD_ACTION;
+#undef BAD_ACTION
}
-
- /* If we have been given a token, but it is not an identifier,
- or a small constant, then something has gone wrong. */
- if (token)
+ else
+ BAD ("malformed '#pragma pack' - ignored");
+
+ if (c_lex (&x) != CPP_EOF)
+ warning ("junk at end of '#pragma pack'");
+
+ if (action != pop)
+ switch (align)
+ {
+ case 0:
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ case 16:
+ align *= BITS_PER_UNIT;
+ break;
+ default:
+ BAD2 ("alignment must be a small power of two, not %d", align);
+ }
+
+ switch (action)
{
- switch (TREE_CODE (token))
- {
- case IDENTIFIER_NODE:
- break;
-
- case INTEGER_CST:
- if (TREE_INT_CST_HIGH (token) != 0)
- return 0;
- break;
-
- default:
- return 0;
- }
+ case set: SET_GLOBAL_ALIGNMENT (align); break;
+ case push: push_alignment (align, id); break;
+ case pop: pop_alignment (id); break;
}
-
- 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;
-
+}
+#endif /* HANDLE_PRAGMA_PACK */
+
#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;
+static void handle_pragma_weak PARAMS ((cpp_reader *));
- 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;
+/* #pragma weak name [= value] */
+static void
+handle_pragma_weak (dummy)
+ cpp_reader *dummy ATTRIBUTE_UNUSED;
+{
+ tree name, value, x;
+ enum cpp_ttype t;
- 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;
+ value = 0;
- case ps_left:
+ if (c_lex (&name) != CPP_NAME)
+ BAD ("malformed #pragma weak, ignored");
+ t = c_lex (&x);
+ if (t == CPP_EQ)
+ {
+ if (c_lex (&value) != CPP_NAME)
+ BAD ("malformed #pragma weak, ignored");
+ t = c_lex (&x);
+ }
+ if (t != CPP_EOF)
+ warning ("junk at end of #pragma weak");
- if (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;
- }
+ add_weak (IDENTIFIER_POINTER (name), value ? IDENTIFIER_POINTER (value) : 0);
+}
#endif
- break;
- default:
- state = ps_bad;
- break;
- }
- break;
-
-#ifdef HANDLE_PRAGMA_PACK_PUSH_POP
- case ps_pop:
+void
+init_pragma ()
+{
+#ifdef HANDLE_PRAGMA_PACK
+ cpp_register_pragma (parse_in, 0, "pack", handle_pragma_pack);
+#endif
+#ifdef HANDLE_PRAGMA_WEAK
+ cpp_register_pragma (parse_in, 0, "weak", handle_pragma_weak);
+#endif
+#ifdef REGISTER_TARGET_PRAGMAS
+ REGISTER_TARGET_PRAGMAS (parse_in);
#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;
+ ggc_add_root (&alignment_stack, 1, sizeof(alignment_stack),
+ mark_align_stack);
+#endif
}
-#endif /* HANDLE_GENERIC_PRAGMAS */
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