[RFC] Another fix for PR c++/41183

[Jie Zhang <jie at codesourcery dot com>]

Hi Jakub,

I just found another way to fix this PR. Why not copy cfun->language 
when we create function clones as the attached patch does. I encountered 
another similar issue, that means I need to add cp_function_chain 
checking in another place. This patch could fix both cases. This patch 
has been bootstrapped and regtested with 
--enable-languages=c,c++,objc,fortran on gcc-4.4 branch. Testing on 
trunk with an adapted patch looks OK, too. How would you like this fix?


Regards,
--
Jie Zhang
CodeSourcery
(650) 331-3385 x735

	gcc/cp/
	* cp-lang.c (cp_copy_cfun_language): New.
	(LANG_HOOKS_COPY_CFUN_LANGUAGE): Define.
	* cp-tree.h (current_class_ptr): Don't check
	cp_function_chain.

	gcc/
	* langhooks.c (lhd_do_nothing_ff): New.
	* langhooks.h (struct lang_hooks): Add copy_cfun_language.
	* tree-inline.c (initialize_cfun): Call
	lang_hooks.copy_cfun_language.
	* langhooks-def.h (lhd_do_nothing_ff): Declare.
	(LANG_HOOKS_COPY_CFUN_LANGUAGE): Define.
	(LANG_HOOKS_INITIALIZER): Add LANG_HOOKS_COPY_CFUN_LANGUAGE.


Index: cp/cp-lang.c
===================================================================
--- cp/cp-lang.c	(revision 157556)
+++ cp/cp-lang.c	(working copy)
@@ -35,6 +35,7 @@ along with GCC; see the file COPYING3.
 
 enum c_language_kind c_language = clk_cxx;
 static void cp_init_ts (void);
+static void cp_copy_cfun_language (struct function *, struct function *);
 static const char * cxx_dwarf_name (tree t, int verbosity);
 static enum classify_record cp_classify_record (tree type);
 
@@ -57,6 +58,8 @@ static enum classify_record cp_classify_
 #define LANG_HOOKS_FOLD_OBJ_TYPE_REF cp_fold_obj_type_ref
 #undef LANG_HOOKS_INIT_TS
 #define LANG_HOOKS_INIT_TS cp_init_ts
+#undef LANG_HOOKS_COPY_CFUN_LANGUAGE
+#define LANG_HOOKS_COPY_CFUN_LANGUAGE cp_copy_cfun_language
 
 /* Each front end provides its own lang hook initializer.  */
 const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
@@ -104,6 +107,18 @@ cp_init_ts (void)
 
 }
 
+static void
+cp_copy_cfun_language (struct function *dst, struct function *src)
+{
+  if (src->language)
+    {
+      if (dst->language == NULL)
+	dst->language = GGC_NEW (struct language_function);
+      memcpy (dst->language, src->language,
+	      sizeof (struct language_function));
+    }
+}
+
 static const char *
 cxx_dwarf_name (tree t, int verbosity)
 {
Index: cp/cp-tree.h
===================================================================
--- cp/cp-tree.h	(revision 157556)
+++ cp/cp-tree.h	(working copy)
@@ -883,8 +883,7 @@ struct language_function GTY(())
    expression for `*this'.  */
 
 #define current_class_ptr \
-  (cfun && cp_function_chain					\
-   ? cp_function_chain->x_current_class_ptr : NULL_TREE)
+  (cfun ? cp_function_chain->x_current_class_ptr : NULL_TREE)
 #define current_class_ref \
   (cfun ? cp_function_chain->x_current_class_ref : NULL_TREE)
 
Index: langhooks.c
===================================================================
--- langhooks.c	(revision 157556)
+++ langhooks.c	(working copy)
@@ -76,6 +76,14 @@ lhd_do_nothing_f (struct function * ARG_
 {
 }
 
+/* Do nothing (function).  */
+
+void
+lhd_do_nothing_ff (struct function * ARG_UNUSED (f),
+		   struct function * ARG_UNUSED (g))
+{
+}
+
 /* Do nothing (return NULL_TREE).  */
 
 tree
Index: langhooks.h
===================================================================
--- langhooks.h	(revision 157556)
+++ langhooks.h	(working copy)
@@ -414,6 +414,9 @@ struct lang_hooks
      if in the process TREE_CONSTANT or TREE_SIDE_EFFECTS need updating.  */
   tree (*expr_to_decl) (tree expr, bool *tc, bool *se);
 
+  /* Copy the lanuage-specific data.  */
+  void (*copy_cfun_language) (struct function *, struct function *);
+
   /* Whenever you add entries here, make sure you adjust langhooks-def.h
      and langhooks.c accordingly.  */
 };
Index: tree-inline.c
===================================================================
--- tree-inline.c	(revision 157556)
+++ tree-inline.c	(working copy)
@@ -1822,8 +1822,10 @@ initialize_cfun (tree new_fndecl, tree c
   gcc_assert (cfun->local_decls == NULL);
   gcc_assert (cfun->cfg == NULL);
   gcc_assert (cfun->decl == new_fndecl);
+  gcc_assert (cfun->language == NULL);
 
   /* Copy items we preserve during clonning.  */
+  lang_hooks.copy_cfun_language (cfun, src_cfun);
   cfun->static_chain_decl = src_cfun->static_chain_decl;
   cfun->nonlocal_goto_save_area = src_cfun->nonlocal_goto_save_area;
   cfun->function_end_locus = src_cfun->function_end_locus;
Index: langhooks-def.h
===================================================================
--- langhooks-def.h	(revision 157556)
+++ langhooks-def.h	(working copy)
@@ -40,6 +40,7 @@ extern void lhd_do_nothing (void);
 extern void lhd_do_nothing_t (tree);
 extern void lhd_do_nothing_i (int);
 extern void lhd_do_nothing_f (struct function *);
+extern void lhd_do_nothing_ff (struct function *, struct function *);
 extern bool lhd_post_options (const char **);
 extern alias_set_type lhd_get_alias_set (tree);
 extern tree lhd_return_null_tree_v (void);
@@ -113,6 +114,7 @@ extern void lhd_omp_firstprivatize_type_
 #define LANG_HOOKS_EXPR_TO_DECL		lhd_expr_to_decl
 #define LANG_HOOKS_TO_TARGET_CHARSET	lhd_to_target_charset
 #define LANG_HOOKS_INIT_TS		lhd_do_nothing
+#define LANG_HOOKS_COPY_CFUN_LANGUAGE	lhd_do_nothing_ff
 
 /* Attribute hooks.  */
 #define LANG_HOOKS_ATTRIBUTE_TABLE		NULL
@@ -270,6 +272,7 @@ extern tree lhd_make_node (enum tree_cod
   LANG_HOOKS_BUILTIN_FUNCTION_EXT_SCOPE, \
   LANG_HOOKS_INIT_TS,          \
   LANG_HOOKS_EXPR_TO_DECL, \
+  LANG_HOOKS_COPY_CFUN_LANGUAGE, \
 }
 
 #endif /* GCC_LANG_HOOKS_DEF_H */