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[C++ PATCH] Don't warn about missing return statement if noreturn function is called in template (PR c++/30988)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Jason Merrill <jason at redhat dot com>, Mark Mitchell <mark at codesourcery dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Sat, 17 Nov 2007 12:20:24 -0500
- Subject: [C++ PATCH] Don't warn about missing return statement if noreturn function is called in template (PR c++/30988)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
Even if a function is called with type dependent args, we might know
that it is a noreturn function which normally surpresses warning about
missing return stmt. Though IMHO it is better to issue a false positive
warning than not warn about missing return.
Regtested on x86_64-linux, ok for trunk?
2007-11-17 Jakub Jelinek <jakub@redhat.com>
PR c++/30988
semantics.c (finish_call_expr): Set current_function_returns_abnormally
if fn is noreturn FUNCTION_DECL or OVERLOAD with all noreturn
functions.
* g++.dg/warn/noreturn-4.C: New test.
* g++.dg/warn/noreturn-5.C: New test.
* g++.dg/warn/noreturn-6.C: New test.
* g++.dg/warn/noreturn-7.C: New test.
--- gcc/cp/semantics.c.jj 2007-11-11 23:00:06.000000000 +0100
+++ gcc/cp/semantics.c 2007-11-17 14:05:39.000000000 +0100
@@ -1846,6 +1846,25 @@ finish_call_expr (tree fn, tree args, bo
{
result = build_nt_call_list (fn, args);
KOENIG_LOOKUP_P (result) = koenig_p;
+ if (cfun)
+ {
+ if (TREE_CODE (fn) == FUNCTION_DECL
+ && TREE_THIS_VOLATILE (fn))
+ current_function_returns_abnormally = 1;
+ else if (TREE_CODE (fn) == OVERLOAD)
+ {
+ bool all_noreturn = true;
+ while (fn)
+ {
+ if (TREE_CODE (OVL_CURRENT (fn)) == FUNCTION_DECL
+ && !TREE_THIS_VOLATILE (OVL_CURRENT (fn)))
+ all_noreturn = false;
+ fn = OVL_NEXT (fn);
+ }
+ if (all_noreturn)
+ current_function_returns_abnormally = 1;
+ }
+ }
return result;
}
if (!BASELINK_P (fn)
--- gcc/testsuite/g++.dg/warn/noreturn-4.C.jj 2007-11-17 14:36:36.000000000 +0100
+++ gcc/testsuite/g++.dg/warn/noreturn-4.C 2007-11-17 14:09:48.000000000 +0100
@@ -0,0 +1,13 @@
+// PR c++/30988
+// { dg-do compile }
+// { dg-options "-O2 -Wall" }
+
+void f (const char *) __attribute__ ((noreturn));
+
+template <typename T> struct A
+{
+ int g ()
+ {
+ f (__FUNCTION__);
+ }
+};
--- gcc/testsuite/g++.dg/warn/noreturn-5.C.jj 2007-11-17 14:36:36.000000000 +0100
+++ gcc/testsuite/g++.dg/warn/noreturn-5.C 2007-11-17 14:09:53.000000000 +0100
@@ -0,0 +1,15 @@
+// PR c++/30988
+// { dg-do compile }
+// { dg-options "-O2 -Wall" }
+
+void f (const char *) __attribute__ ((noreturn));
+void f (int) __attribute__ ((noreturn));
+void f (double) __attribute__ ((noreturn));
+
+template <typename T> struct A
+{
+ int g ()
+ {
+ f ((T) 0);
+ }
+};
--- gcc/testsuite/g++.dg/warn/noreturn-6.C.jj 2007-11-17 14:36:36.000000000 +0100
+++ gcc/testsuite/g++.dg/warn/noreturn-6.C 2007-11-17 14:09:59.000000000 +0100
@@ -0,0 +1,13 @@
+// PR c++/30988
+// { dg-do compile }
+// { dg-options "-O2 -Wall" }
+
+void f (const char *);
+
+template <typename T> struct A
+{
+ int g ()
+ {
+ f (__FUNCTION__);
+ } // { dg-warning "no return statement in function returning non-void" }
+};
--- gcc/testsuite/g++.dg/warn/noreturn-7.C.jj 2007-11-17 14:36:36.000000000 +0100
+++ gcc/testsuite/g++.dg/warn/noreturn-7.C 2007-11-17 14:10:18.000000000 +0100
@@ -0,0 +1,15 @@
+// PR c++/30988
+// { dg-do compile }
+// { dg-options "-O2 -Wall" }
+
+void f (const char *) __attribute__ ((noreturn));
+void f (int);
+void f (double) __attribute__ ((noreturn));
+
+template <typename T> struct A
+{
+ int g ()
+ {
+ f ((T) 0);
+ } // { dg-warning "no return statement in function returning non-void" }
+};
Jakub