PR ada/20548

	* common.opt (-fstack-check): Do not declare the variable here.
	(-fstack-check=): New option variant.
	* doc/invoke.texi (Code Gen Options): Document it.
	* expr.h (STACK_OLD_CHECK_PROTECT): New macro.
	(STACK_CHECK_PROTECT): Bump to 3 pages if DWARF-2 EH is used.
	(STACK_CHECK_STATIC_BUILTIN): New macro.
	* doc/tm.texi (Stack Checking): Document STACK_CHECK_STATIC_BUILTIN.
	* opts.c: Include expr.h.
	(common_handle_option) <OPT_fold_stack_check_>: New case.
	<OPT_fstack_check>: Likewise.
	* calls.c (initialize_argument_information): Use TYPE_SIZE_UNIT
	consistently in the test for variable-sized types.  Adjust for
	new behaviour of flag_stack_check.
	* explow.c: Include except.h.
	(allocate_dynamic_stack_space): Do not take into account
	STACK_CHECK_MAX_FRAME_SIZE for static builtin stack checking.
	* function.c (gimplify_parameters): Use DECL_SIZE_UNIT in the test
	for variable-sized parameters.  Treat all parameters whose size is
	greater than STACK_CHECK_MAX_VAR_SIZE as variable-sized if generic
	stack checking is enabled.
	* gimplify.c (gimplify_decl_expr): Treat non-static objects whose
	size is greater than STACK_CHECK_MAX_VAR_SIZE as variable-sized
	if generic stack checking is enabled.
	(expand_function_end): Adjust for new behaviour of flag_stack_check.
	* reload1.c (reload): Likewise.
	* stmt.c (expand_decl): Assert that all automatic variables have
	fixed size at this point and remove dead code.
	* flags.h (stack_check_type): New enumeration type.
	(flag_stack_check): Declare.
	* toplev.c (flag_stack_check): New global variable.
	* Makefile.in (opts.o): Add dependency on EXPR_H.
	(explow.o): Add dependency on except.h.
ada/
	* gcc-interface/decl.c (gnat_to_gnu_entity): Use DECL_SIZE_UNIT in the
	setjmp test consistently.  Adjust for new behaviour of flag_stack_check.
	* gcc-interface/utils2.c (build_call_alloc_dealloc): Remove redundant
	test of flag_stack_check.  Adjust for new behaviour of flag_stack_check.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@139159 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 41 deletions

diff --git a/gcc/stmt.c b/gcc/stmt.c
index 38d7b439aec..f05cd0956fc 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -1867,8 +1867,8 @@ expand_decl (tree decl)
     SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
 
   else if (DECL_SIZE (decl) == 0)
-    /* Variable with incomplete type.  */
     {
+      /* Variable with incomplete type.  */
       rtx x;
       if (DECL_INITIAL (decl) == 0)
 	/* Error message was already done; now avoid a crash.  */
@@ -1899,16 +1899,15 @@ expand_decl (tree decl)
 			  TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
     }
 
-  else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
-	   && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
-		 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
-					  STACK_CHECK_MAX_VAR_SIZE)))
+  else
     {
-      /* Variable of fixed size that goes on the stack.  */
       rtx oldaddr = 0;
       rtx addr;
       rtx x;
 
+      /* Variable-sized decls are dealt with in the gimplifier.  */
+      gcc_assert (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST);
+
       /* If we previously made RTL for this decl, it must be an array
 	 whose size was determined by the initializer.
 	 The old address was a register; set that register now
@@ -1936,41 +1935,6 @@ expand_decl (tree decl)
 	    emit_move_insn (oldaddr, addr);
 	}
     }
-  else
-    /* Dynamic-size object: must push space on the stack.  */
-    {
-      rtx address, size, x;
-
-      /* Record the stack pointer on entry to block, if have
-	 not already done so.  */
-      do_pending_stack_adjust ();
-
-      /* Compute the variable's size, in bytes.  This will expand any
-	 needed SAVE_EXPRs for the first time.  */
-      size = expand_normal (DECL_SIZE_UNIT (decl));
-      free_temp_slots ();
-
-      /* Allocate space on the stack for the variable.  Note that
-	 DECL_ALIGN says how the variable is to be aligned and we
-	 cannot use it to conclude anything about the alignment of
-	 the size.  */
-      address = allocate_dynamic_stack_space (size, NULL_RTX,
-					      TYPE_ALIGN (TREE_TYPE (decl)));
-
-      /* Reference the variable indirect through that rtx.  */
-      x = gen_rtx_MEM (DECL_MODE (decl), address);
-      set_mem_attributes (x, decl, 1);
-      SET_DECL_RTL (decl, x);
-
-
-      /* Indicate the alignment we actually gave this variable.  */
-#ifdef STACK_BOUNDARY
-      DECL_ALIGN (decl) = STACK_BOUNDARY;
-#else
-      DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
-#endif
-      DECL_USER_ALIGN (decl) = 0;
-    }
 }
 
 /* Emit code to save the current value of stack.  */