common.opt (fsplit-stack): New option.

gcc/:
	* common.opt (fsplit-stack): New option.
	* opts.c (decode_options): Set flag_split_stack to final value.
	* target.def (supports_split_stack): New hook.
	* gcc.c (STACK_SPLIT_SPEC): Define.
	(LINK_COMMAND_SPEC): Use STACK_SPLIT_SPEC.
	* doc/invoke.texi (Option Summary): Mention -fsplit-stack.
	(Code Gen Options): Document -fsplit-stack.
	* doc/extend.texi (Function Attributes): Mention no_split_stack.
	(Function Attributes): Document no_split_stack.
	* doc/tm.texi.in (Stack Smashing Protection): Add @hook
	TARGET_SUPPORTS_SPLIT_STACK.
	* doc/tm.texi: Rebuild.
	* function.c (thread_prologue_and_epilogue_insns): If
	flag_split_stack, add split stack prologue.
	* explow.c (allocate_dynamic_stack_space): Support -fsplit-stack.
	* varasm.c (saw_no_split_stack): New static variable.
	(assemble_start_function): Set saw_no_split_stack if the function
	has the no_split_stack attribute.
	(file_end_indicate_split_stack): New function.
	* output.h (file_end_indicate_split_stack): Declare.
	* libgcc-std.ver (GCC_4.6.0): Add -fsplit-stack support variables
	and function.
	* doc/libgcc.texi (Miscellaneous routines): Document -fsplit-stack
	routines.
	* config/i386/i386.c (ix86_option_override_internal): Don't set
	expand_builtin_va_start to NULL if -fsplit-stack.
	(ix86_function_regparm): Reduce local regparm by 1 for 32-bit
	-fsplit-stack.
	(ix86_va_start): If -fsplit-stack, get overflow pointer	from
	scratch register set by prologue.
	(ix86_code_end): If -fsplit-stack, call
	file_end_indicate_split_stack.
	(ix86_supports_split_stack): New static function.
	(SPLIT_STACK_AVAILABLE): Define.
	(split_stack_prologue_scratch_regno): New static function.
	(split_stack_fn): New static variable.
	(ix86_expand_split_stack_prologue): New function.
	(ix86_live_on_entry): New static function.
	(ix86_legitimate_address_p): Handle UNSPEC_STACK_CHECK.
	(output_pic_addr_const): Likewise.
	(i386_asm_output_addr_const_extra): Likewise.
	(ix86_expand_call): Change return type to rtx.  Return the new
	call instruction.
	(TARGET_SUPPORTS_SPLIT_STACK): Define.
	(TARGET_EXTRA_LIVE_ON_ENTRY): Define.
	* config/i386/i386.md (UNSPEC_STACK_CHECK): Define.
	(split_stack_prologue, split_stack_return): New insns.
	(split_stack_space_check): New insn.
	* config/i386/i386.h (struct machine_function): Add
	split_stack_varargs_pointer field.
	* config/i386/linux.h (TARGET_CAN_SPLIT_STACK): Define.
	(TARGET_THREAD_SPLIT_STACK_OFFSET): Define.
	* config/i386/linux64.h (TARGET_CAN_SPLIT_STACK): Define.
	(TARGET_THREAD_SPLIT_STACK_OFFSET): Define.
	* config/i386/i386-protos.h (ix86_expand_split_stack_prologue):
	Declare.
	(ix86_expand_call): Update declaration.
gcc/c-family/:
	* c-common.c (c_common_attribute_table): Add no_split_stack.
	(handle_no_split_stack_attribute): New static function.
gcc/testsuite/:
	* lib/target-supports.exp (check_effective_target_split_stack):
	New procedure.
	* gcc.dg/split-1.c: New test.
	* gcc.dg/split-2.c: New test.
	* gcc.dg/split-3.c: New test.
	* gcc.dg/split-4.c: New test.
libgcc/:
	* generic-morestack.h: New file.
	* generic-morestack.c: New file.
	* generic-morestack-thread.c: New file.
	* config/i386/morestack.S: New file.
	* config/t-stack: New file.
	* config/i386/t-stack-i386: New file.
	* config.host (i[34567]86-*-linux* and friends): Add t-stack and
	i386/t-stack-i386 to tmake_file.

From-SVN: r164661

2 files changed, 34 insertions, 0 deletions

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 25603f9..e16c871 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,8 @@
+2010-09-27  Ian Lance Taylor  <iant@google.com>
+
+	* c-common.c (c_common_attribute_table): Add no_split_stack.
+	(handle_no_split_stack_attribute): New static function.
+
 2010-09-27  Nicola Pero  <nicola.pero@meta-innovation.com>
 
 	Merge from 'apple/trunk' branch on FSF servers.	
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 6ef3bf9..63e2d70f 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -358,6 +358,7 @@ static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
 static tree handle_alloc_size_attribute (tree *, tree, tree, int, bool *);
 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
+static tree handle_no_split_stack_attribute (tree *, tree, tree, int, bool *);
 static tree handle_fnspec_attribute (tree *, tree, tree, int, bool *);
 
 static void check_function_nonnull (tree, int, tree *);
@@ -661,6 +662,8 @@ const struct attribute_spec c_common_attribute_table[] =
 			      handle_target_attribute },
   { "optimize",               1, -1, true, false, false,
 			      handle_optimize_attribute },
+  { "no_split_stack",	      0, 0, true,  false, false,
+			      handle_no_split_stack_attribute },
   /* For internal use (marking of builtins and runtime functions) only.
      The name contains space to prevent its usage in source code.  */
   { "fn spec",	 	      1, 1, false, true, true,
@@ -7841,6 +7844,32 @@ handle_optimize_attribute (tree *node, tree name, tree args,
 
   return NULL_TREE;
 }
+
+/* Handle a "no_split_stack" attribute.  */
+
+static tree
+handle_no_split_stack_attribute (tree *node, tree name,
+				 tree ARG_UNUSED (args),
+				 int ARG_UNUSED (flags),
+				 bool *no_add_attrs)
+{
+  tree decl = *node;
+
+  if (TREE_CODE (decl) != FUNCTION_DECL)
+    {
+      error_at (DECL_SOURCE_LOCATION (decl),
+		"%qE attribute applies only to functions", name);
+      *no_add_attrs = true;
+    }
+  else if (DECL_INITIAL (decl))
+    {
+      error_at (DECL_SOURCE_LOCATION (decl),
+		"can%'t set %qE attribute after definition", name);
+      *no_add_attrs = true;
+    }
+
+  return NULL_TREE;
+}
 
 /* Check for valid arguments being passed to a function.
    ATTRS is a list of attributes.  There are NARGS arguments in the array