re PR c/10178 (ICE in tree_low_cst)

	PR 10178
	* langhooks.h (struct lang_hooks): Add no_body_blocks bool.
	* langhooks-def.h (LANG_HOOKS_NO_BODY_BLOCKS): New; default false.
	* c-lang.c, objc/objc-lang.c: Override LANG_HOOKS_NO_BODY_BLOCKS
	to true.
	* stmt.c (is_body_block): If lang_hooks.no_body_blocks, always
	return 0.

From-SVN: r68483

gcc/ChangeLog

+2003-06-25  Zack Weinberg  <zack@codesourcery.com>
+
+	PR 10178
+	* langhooks.h (struct lang_hooks): Add no_body_blocks bool.
+	* langhooks-def.h (LANG_HOOKS_NO_BODY_BLOCKS): New; default false.
+	* c-lang.c, objc/objc-lang.c: Override LANG_HOOKS_NO_BODY_BLOCKS
+	to true.
+	* stmt.c (is_body_block): If lang_hooks.no_body_blocks, always
+	return 0.
+
 2003-06-25  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* Makefile.in (bt-load.o): Depend on $(TM_P_H).

gcc/c-lang.c

@@ -67,6 +67,8 @@ static int c_init_options (void);
 #define LANG_HOOKS_UNSAFE_FOR_REEVAL c_common_unsafe_for_reeval
 #undef LANG_HOOKS_STATICP
 #define LANG_HOOKS_STATICP c_staticp
+#undef LANG_HOOKS_NO_BODY_BLOCKS
+#define LANG_HOOKS_NO_BODY_BLOCKS true
 #undef LANG_HOOKS_WARN_UNUSED_GLOBAL_DECL
 #define LANG_HOOKS_WARN_UNUSED_GLOBAL_DECL c_warn_unused_global_decl
 #undef LANG_HOOKS_PRINT_IDENTIFIER

gcc/langhooks-def.h

@@ -107,6 +107,7 @@ void write_global_declarations PARAMS ((void));
 #define LANG_HOOKS_SET_DECL_ASSEMBLER_NAME lhd_set_decl_assembler_name
 #define LANG_HOOKS_CAN_USE_BIT_FIELDS_P lhd_can_use_bit_fields_p
 #define LANG_HOOKS_HONOR_READONLY	false
+#define LANG_HOOKS_NO_BODY_BLOCKS	false
 #define LANG_HOOKS_PRINT_STATISTICS	lhd_do_nothing
 #define LANG_HOOKS_PRINT_XNODE		lhd_print_tree_nothing
 #define LANG_HOOKS_PRINT_DECL		lhd_print_tree_nothing
@@ -266,6 +267,7 @@ int lhd_tree_dump_type_quals			PARAMS ((tree));
   LANG_HOOKS_SET_DECL_ASSEMBLER_NAME, \
   LANG_HOOKS_CAN_USE_BIT_FIELDS_P, \
   LANG_HOOKS_HONOR_READONLY, \
+  LANG_HOOKS_NO_BODY_BLOCKS, \
   LANG_HOOKS_PRINT_STATISTICS, \
   LANG_HOOKS_PRINT_XNODE, \
   LANG_HOOKS_PRINT_DECL, \

gcc/langhooks.h

@@ -328,6 +328,11 @@ struct lang_hooks
   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
   bool honor_readonly;
 
+  /* Nonzero if this front end does not generate a dummy BLOCK between
+     the outermost scope of the function and the FUNCTION_DECL.  See
+     is_body_block in stmt.c, and its callers.  */
+  bool no_body_blocks;
+
   /* The front end can add its own statistics to -fmem-report with
      this hook.  It should output to stderr.  */
   void (*print_statistics) PARAMS ((void));

gcc/objc/objc-lang.c

@@ -65,6 +65,8 @@ static int objc_init_options                   PARAMS ((void));
 #define LANG_HOOKS_UNSAFE_FOR_REEVAL c_common_unsafe_for_reeval
 #undef LANG_HOOKS_STATICP
 #define LANG_HOOKS_STATICP c_staticp
+#undef LANG_HOOKS_NO_BODY_BLOCKS
+#define LANG_HOOKS_NO_BODY_BLOCKS true
 #undef LANG_HOOKS_DUP_LANG_SPECIFIC_DECL
 #define LANG_HOOKS_DUP_LANG_SPECIFIC_DECL c_dup_lang_specific_decl
 #undef LANG_HOOKS_PRINT_IDENTIFIER

gcc/stmt.c

@@ -3511,6 +3511,9 @@ int
 is_body_block (stmt)
      tree stmt;
 {
+  if (lang_hooks.no_body_blocks)
+    return 0;
+
   if (TREE_CODE (stmt) == BLOCK)
     {
       tree parent = BLOCK_SUPERCONTEXT (stmt);