* Makefile.in (calls.o): Depend on except.h.

	* calls.c: Include except.h.
	(emit_call_1): Call note_eh_region_may_contain_throw if
	appropriate.
	* except.c (eh_region): Add may_contain_throw.
	(expand_eh_region_end_cleanup): Do not include handler code when
	it cannot be reached.
	(note_eh_region_may_contain_throw): New function.
	* except.h (note_eh_region_may_contain_throw): New function.

	* call.c (build_over_call): Use build_cxx_call.
	(build_cxx_call): New method, split out of build_over_call.
	* cp-tree.h (language_function): Add can_throw.
	(build_cxx_call): Declare it.
	* decl.c (finish_function): If a function does not contain any
	calls to functions that can throw an exception, indicate that
	fact.
	* decl2.c (mark_used): Do not defer the instantiation of
	functions, if the current function does not throw.
	* optimize.c (maybe_clone_body): Copy TREE_NOTHROW to the clones.
	* pt.c (instantiate_decl): Make sure import_export_decl is called
	before emitting things.
	* rtti.c (throw_bad_cast): Use build_cxx_call.
	(build_dynamic_cast_1): Likewise.
	* typeck.c (build_function_call): Likewise.

	* g++.dg/template/recurse.C: Adjust location of error messages.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@65929 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 27 insertions, 1 deletions

diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 7b7dd471be5..3f9c66fd4d4 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -4581,7 +4581,33 @@ mark_used (tree decl)
       && DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl)
       && (!DECL_EXPLICIT_INSTANTIATION (decl)
 	  || (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))))
-    instantiate_decl (decl, /*defer_ok=*/1);
+    {
+      bool defer;
+
+      /* Normally, we put off instantiating functions in order to
+	 improve compile times.  Maintaining a stack of active
+	 functions is expensive, and the inliner knows to
+	 instantiate any functions it might need.
+
+	 However, if instantiating this function might help us mark
+	 the current function TREE_NOTHROW, we go ahead and
+	 instantiate it now.  */
+      defer = (!flag_exceptions
+	       || TREE_CODE (decl) != FUNCTION_DECL
+	       /* If the called function can't throw, we don't need to
+		  generate its body to find that out.  */
+	       || TREE_NOTHROW (decl)
+	       || !cfun
+	       /* If we already know the current function can't throw,
+		  then we don't need to work hard to prove it.  */
+	       || TREE_NOTHROW (current_function_decl)
+	       /* If we already know that the current function *can*
+		  throw, there's no point in gathering more
+		  information.  */
+	       || cp_function_chain->can_throw);
+
+      instantiate_decl (decl, defer);
+    }
 }
 
 /* Called when a class-head is encountered.  TAG_KIND is the class-key