re PR middle-end/41573 (segfault in trunk related to strings)

	PR middle-end/41573
	* builtins.c (fold_builtin_isascii): Use fold_build2.
	(fold_builtin_isdigit): Ditto.
	* except.c (duplicate_eh_regions_1): Tolerate NULL labels.
	* tree-cfg.c (struct rus_data, remove_useless_stmts_warn_notreached,
	remove_useless_stmts_cond, remove_useless_stmts_tf,
	remove_useless_stmts_tc, remove_useless_stmts_bind,
	remove_useless_stmts_goto, remove_useless_stmts_label,
	remove_useless_stmts_1, remove_useless_stmts,
	pass_remove_useless_stmts): Remove.
	* tree-pass.h (pass_remove_useless_stmts): Don't declare.
	* passes.c (init_optimization_passes): Don't add
	pass_remove_useless_stmts.
	* tree-eh.c (lower_eh_constructs_2): Handle empty cleanups.
	* tree.c (free_lang_data_in_decl): Don't clear DECL_INITIAL of
	static constants.
	* lto-symtab.c (lto_symtab_register_decl): Accepts DECL_INITIAL
	for static constants.
	* lto-streamer-out.c (output_gimple_stmt): Handle GIMPLE_NOP.
	* lto-streamer-in.c (input_gimple_stmt): Handle GIMPLE_NOP.

testsuite/
	* gcc.dg/tree-ssa/foldstring-1.c: Use fre dump.
	* gcc.dg/tree-ssa/useless-1.c: Use gimple dump.
	* gcc.dg/pr41573.c: New test.

From-SVN: r152563

1 files changed, 2 insertions, 1 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 77ba3f8..4c3f52b 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -4438,7 +4438,8 @@ free_lang_data_in_decl (tree decl)
 	  && !TREE_STATIC (expr) && !DECL_EXTERNAL (expr))
 	SET_DECL_DEBUG_EXPR (decl, NULL_TREE);
 
-      if (DECL_EXTERNAL (decl))
+      if (DECL_EXTERNAL (decl)
+	  && (!TREE_STATIC (decl) || !TREE_READONLY (decl)))
 	DECL_INITIAL (decl) = NULL_TREE;
     }
   else if (TREE_CODE (decl) == TYPE_DECL)