mark_used is wrongly diagnosing a use of a TEMPLATE_DECL (e.g. the call
to f1 in function f3 of auto-fn29.C below) for having an undeduced
'auto' return type. This doesn't make sense, because an 'auto' used
inside a template doesn't get deduced until after the template is
instantiated. So for a TEMPLATE_DECL we shouldn't diagnose a use of
undeduced 'auto' here. After instantiation, presumably we will call
mark_used on the resulting FUNCTION_DECL which will check for undeduced
auto appropriately.
Bootstrapped and regtested on x86_64-pc-linux-gnu, no new regressions.
Is this OK to commit?
gcc/cp/ChangeLog:
PR c++/69283
PR c++/67835
* decl2.c (mark_used): Don't complain about an undeduced 'auto'
in a TEMPLATE_DECL.
gcc/testsuite/ChangeLog:
PR c++/69283
PR c++/67835
* g++.dg/cpp1y/auto-fn29.C: New test.
* g++.dg/cpp1y/auto-fn30.C: New test.
* g++.dg/cpp1y/auto-fn31.C: New test.
---
gcc/cp/decl2.c | 4 +++-
gcc/testsuite/g++.dg/cpp1y/auto-fn29.C | 23 +++++++++++++++++++++++
gcc/testsuite/g++.dg/cpp1y/auto-fn30.C | 21 +++++++++++++++++++++
gcc/testsuite/g++.dg/cpp1y/auto-fn31.C | 22 ++++++++++++++++++++++
4 files changed, 69 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/auto-fn29.C
create mode 100644 gcc/testsuite/g++.dg/cpp1y/auto-fn30.C
create mode 100644 gcc/testsuite/g++.dg/cpp1y/auto-fn31.C
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index a7212ca0..849375f 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -5112,7 +5112,9 @@ mark_used (tree decl, tsubst_flags_t complain)
|| DECL_LANG_SPECIFIC (decl) == NULL
|| DECL_THUNK_P (decl))
{
- if (!processing_template_decl && type_uses_auto (TREE_TYPE (decl)))
+ if (!processing_template_decl
+ && TREE_CODE (decl) != TEMPLATE_DECL
+ && type_uses_auto (TREE_TYPE (decl)))
{
if (complain & tf_error)
error ("use of %qD before deduction of %<auto%>", decl);
diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn29.C
b/gcc/testsuite/g++.dg/cpp1y/auto-fn29.C
new file mode 100644
index 0000000..cd10460
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn29.C
@@ -0,0 +1,23 @@
+// PR c++/69283
+// { dg-do compile { target c++14 } }
+
+namespace Ape {
+ struct Type {};
+
+ template <typename T>
+ auto f1(T const& v){
+ return true;
+ }
+}
+
+namespace Baboon {
+ template <typename T>
+ bool f3(T const& v){
+ return f1(v);
+ }
+}
+
+int main(){
+ Ape::Type x;
+ Baboon::f3(x);
+}
diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn30.C
b/gcc/testsuite/g++.dg/cpp1y/auto-fn30.C
new file mode 100644
index 0000000..e005e6e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn30.C
@@ -0,0 +1,21 @@
+// PR c++/67835
+// { dg-do compile { target c++14 } }
+
+template<class Tag, class T>
+auto g(Tag tag, T x) {
+ return f(tag, x);
+}
+
+namespace abc {
+struct tag {};
+
+struct A {};
+
+template<class T>
+auto f(tag, T x) { return x; }
+}
+
+int main() {
+ g(abc::tag(), abc::A());
+ return 0;
+}
diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn31.C
b/gcc/testsuite/g++.dg/cpp1y/auto-fn31.C
new file mode 100644
index 0000000..7849632
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn31.C
@@ -0,0 +1,22 @@
+// { dg-do compile { target c++14 } }
+
+namespace Ape {
+ struct Type {};
+
+ template <typename T>
+ auto f1(T const& v){
+ return f1(v); // { dg-error "auto" }
+ }
+}
+
+namespace Baboon {
+ template <typename T>
+ void f3(T const& v){
+ f1(v);
+ }
+}
+
+int main(){
+ Ape::Type x;
+ Baboon::f3(x);
+}
--
2.7.0.83.gdfccd77.dirty
