From 4ff685a8705e8ee55fa86e75afb769ffb0975aea Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Sat, 25 Apr 2020 00:11:35 +0200
Subject: [PATCH] c++: Avoid -Wreturn-type warning if a template fn calls
noreturn template fn [PR94742]
finish_call_expr already has code to set current_function_returns_abnormally
if a template calls a noreturn function, but on the following testcase it
doesn't call a FUNCTION_DECL, but TEMPLATE_DECL instead, in which case
we didn't check noreturn at all and just assumed it could return.
2020-04-25 Jakub Jelinek <jakub@redhat.com>
PR c++/94742
* semantics.c (finish_call_expr): When looking if all overloads
are noreturn, use STRIP_TEMPLATE to look through TEMPLATE_DECLs.
* g++.dg/warn/Wreturn-type-12.C: New test.
---
gcc/cp/ChangeLog | 6 ++++++
gcc/cp/semantics.c | 2 +-
gcc/testsuite/ChangeLog | 3 +++
gcc/testsuite/g++.dg/warn/Wreturn-type-12.C | 23 +++++++++++++++++++++
4 files changed, 33 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/warn/Wreturn-type-12.C
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 4d3049e67f35..5b9ff5a694cd 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2020-04-25 Jakub Jelinek <jakub@redhat.com>
+
+ PR c++/94742
+ * semantics.c (finish_call_expr): When looking if all overloads
+ are noreturn, use STRIP_TEMPLATE to look through TEMPLATE_DECLs.
+
2020-04-24 Martin Liska <mliska@suse.cz>
* coroutines.cc: Fix compilation error for release checking
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index c7a6064e9f33..64a7b76d4378 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -2508,7 +2508,7 @@ finish_call_expr (tree fn, vec<tree, va_gc> **args, bool disallow_virtual,
bool abnormal = true;
for (lkp_iterator iter (fn); abnormal && iter; ++iter)
{
- tree fndecl = *iter;
+ tree fndecl = STRIP_TEMPLATE (*iter);
if (TREE_CODE (fndecl) != FUNCTION_DECL
|| !TREE_THIS_VOLATILE (fndecl))
abnormal = false;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index fa583670bafc..b9be66865cda 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
2020-04-25 Jakub Jelinek <jakub@redhat.com>
+ PR c++/94742
+ * g++.dg/warn/Wreturn-type-12.C: New test.
+
PR tree-optimization/94734
PR tree-optimization/89430
* gcc.dg/tree-ssa/pr89430-1.c: Add xfail.
diff --git a/gcc/testsuite/g++.dg/warn/Wreturn-type-12.C b/gcc/testsuite/g++.dg/warn/Wreturn-type-12.C
new file mode 100644
index 000000000000..b35d3faafb05
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wreturn-type-12.C
@@ -0,0 +1,23 @@
+// PR c++/94742
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wreturn-type" }
+
+template <class T>
+[[noreturn]] void
+foo (T const &t, char const *)
+{
+ throw T (t);
+}
+
+template <class U>
+int
+bar ()
+{
+ foo (42, __FUNCTION__);
+} // { dg-bogus "no return statement in function returning non-void" }
+
+int
+main ()
+{
+ bar<long>();
+}
--
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