c-common.c (enum attrs): Add A_NO_LIMIT_STACK.

* c-common.c (enum attrs): Add A_NO_LIMIT_STACK.
(init_attributes): Add A_NO_LIMIT_STACK.
(decl_attributes): Handle A_NO_LIMIT_STACK.
* c-decl.c (duplicate_decls): Handle DECL_NO_LIMIT_STACK.
* explow.c (allocate_dynamic_stack_space) [!HAVE_allocate_stack]:
Handle stack bounds checking.
* flags.h (flag_stack_check): Use the word 'probe' rather than
'check', because the flag doesn't actually cause any checking to
be done.
* function.c (expand_function_start): Set
current_function_limit_stack.
* function.h (struct function): Add limit_stack.
(current_function_limit_stack): Define.
* invoke.texi (Code Gen Options): Document new options.
* rtl.h: Declare stack_limit_rtx.
* toplev.c (stack_limit_rtx): New variable.
(decode_f_option): Handle new options -fstack-limit-register=REG,
-fstack-limit-symbol=IDENT, -fno-stack-limit.
(main): Add stack_limit_rtx as GC root.
* tree.h (DECL_NO_LIMIT_STACK): New macro.
(struct tree_decl): New member no_limit_stack.

* config/rs6000/rs6000.c (rs6000_allocate_stack_space): Handle
stack_limit_rtx.
* config/rs6000/rs6000.md (allocate_stack): Handle stack_limit_rtx.
(conditional_trap+1): Get new mnemonic correct.
(conditional_trap+2): New pattern for DImode traps.

* config/m68k/m68k.c (output_function_prologue): Handle
stack_limit_rtx.
* config/m68k/m68k.md (trap): New insn.
(conditional_trap): New insn.
* md.texi (Standard Names): Document `trap' and
`conditional_trap'.
* optabs.c (gen_cond_trap): Use start_sequence()/end_sequence()
so a cc0 setter doesn't get emitted at some random place in the
function.

* config/i960/i960.md (trap): New insn.
(conditional_trap): New expander.
(conditional_trap+1, conditional_trap+2): New insns for signed
and unsigned cases.
* config/i960/i960.c (i960_function_prologue): Use
STARTING_FRAME_OFFSET.  Handle stack_limit_rtx.

Co-Authored-By: Greg McGary <gkm@gnu.org>

From-SVN: r30771

1 files changed, 29 insertions, 0 deletions

diff --git a/gcc/toplev.c b/gcc/toplev.c
index 70ea2a1..fbbbb64 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -720,6 +720,15 @@ int flag_pack_struct = 0;
    to be allocated dynamically.  */
 int flag_stack_check;
 
+/* When non-NULL, indicates that whenever space is allocated on the
+   stack, the resulting stack pointer must not pass this
+   address---that is, for stacks that grow downward, the stack pointer
+   must always be greater than or equal to this address; for stacks
+   that grow upward, the stack pointer must be less than this address.
+   At present, the rtx may be either a REG or a SYMBOL_REF, although
+   the support provided depends on the backend.  */
+rtx stack_limit_rtx;
+
 /* -fcheck-memory-usage causes extra code to be generated in order to check
    memory accesses.  This is used by a detector of bad memory accesses such
    as Checker.  */
@@ -4889,6 +4898,25 @@ decode_f_option (arg)
     align_jumps = read_integral_parameter (arg + 12, arg - 2, align_jumps);
   else if (!strncmp (arg, "align-labels=", 13))
     align_labels = read_integral_parameter (arg + 13, arg - 2, align_labels);
+  else if (!strncmp (arg, "stack-limit-register=", 21))
+    {
+      int reg = decode_reg_name (arg + 21);
+      if (reg < 0)
+	error ("unrecognized register name `%s'", arg + 21);
+      else
+	stack_limit_rtx = gen_rtx_REG (Pmode, reg);
+    }
+  else if (!strncmp (arg, "stack-limit-symbol=", 19))
+    {
+      char *nm;
+      if (ggc_p)
+	nm = ggc_alloc_string (arg + 19, strlen (arg + 19));
+      else
+	nm = xstrdup (arg + 19);
+      stack_limit_rtx = gen_rtx_SYMBOL_REF (Pmode, nm);
+    }
+  else if (!strcmp (arg, "no-stack-limit"))
+    stack_limit_rtx = NULL_RTX;
   else if (!strcmp (arg, "preprocessed"))
     /* Recognise this switch but do nothing.  This prevents warnings
        about an unrecognised switch if cpplib has not been linked in.  */
@@ -5323,6 +5351,7 @@ main (argc, argv)
   init_ggc ();
   ggc_add_root (&input_file_stack, 1, sizeof input_file_stack,
 		&mark_file_stack);
+  ggc_add_rtx_root (&stack_limit_rtx, 1);
 
   /* Perform language-specific options intialization.  */
   lang_init_options ();