* 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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@30771 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 27 insertions, 0 deletions

diff --git a/gcc/explow.c b/gcc/explow.c
index 437c9352631..ca4259a7fa4 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -1333,6 +1333,33 @@ allocate_dynamic_stack_space (size, target, known_align)
       emit_move_insn (target, virtual_stack_dynamic_rtx);
 #endif
       size = convert_modes (Pmode, ptr_mode, size, 1);
+
+      /* Check stack bounds if necessary.  */
+      if (current_function_limit_stack)
+	{
+	  rtx available;
+	  rtx space_available = gen_label_rtx ();
+#ifdef STACK_GROWS_DOWNWARD
+	  available = expand_binop (Pmode, sub_optab, 
+				    stack_pointer_rtx, stack_limit_rtx,
+				    NULL_RTX, 1, OPTAB_WIDEN);
+#else
+	  available = expand_binop (Pmode, sub_optab, 
+				    stack_limit_rtx, stack_pointer_rtx,
+				    NULL_RTX, 1, OPTAB_WIDEN);
+#endif
+	  emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
+				   0, space_available);
+#ifdef HAVE_trap
+	  if (HAVE_trap)
+	    emit_insn (gen_trap ());
+	  else
+#endif
+	    error ("stack limits not supported on this target");
+	  emit_barrier ();
+	  emit_label (space_available);
+	}
+
       anti_adjust_stack (size);
 #ifdef SETJMP_VIA_SAVE_AREA
       if (setjmpless_size != NULL_RTX)