Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/branches?
-- >8 --
Here we crash because a TARGET_EXPR gets into tsubst_expr with something
like:
template<typename>
constexpr static A a = (A{}, A{});
Pre r14-4796, when we had tsubst_copy, we didn't crash because we had
an early exit when substituting with args=NULL_TREE. tsubst_expr
deliberately doesn't have that early exit.
Note that
template<typename>
constexpr static A a = A{};
works because expand_aggr_init_1 sees a COMPOUND_LITERAL_P and does the
early exit without calling expand_default_init. But with a COMPOUND_EXPR
we don't take that path.
The TARGET_EXPR is created via check_initializer -> build_aggr_init_full_exprs
-> build_aggr_init -> expand_aggr_init_1 -> expand_default_init -> ocp_convert
-> build_cplus_new -> build_target_expr. I tried adjusting the big
and ugly check in check_initializer before build_aggr_init_full_exprs
but that didn't work out. I also tried avoiding the call to ocp_convert
but that broke some reflection tests. But avoiding the call to
build_cplus_new seems to work.
PR c++/125539
gcc/cp/ChangeLog:
* cvt.cc (ocp_convert): Don't call build_cplus_new in a
template.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/var-templ89.C: New test.
---
gcc/cp/cvt.cc | 4 ++-
gcc/testsuite/g++.dg/cpp1y/var-templ89.C | 32 ++++++++++++++++++++++++
2 files changed, 35 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ89.C
diff --git a/gcc/cp/cvt.cc b/gcc/cp/cvt.cc
index b1176317d99..571f2e64d03 100644
--- a/gcc/cp/cvt.cc
+++ b/gcc/cp/cvt.cc
@@ -985,7 +985,9 @@ ocp_convert (tree type, tree expr, int convtype, int flags,
type, flags, complain);
}
if (ctor)
- return build_cplus_new (type, ctor, complain);
+ return (processing_template_decl
+ ? ctor
+ : build_cplus_new (type, ctor, complain));
}
if (complain & tf_error)
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ89.C
b/gcc/testsuite/g++.dg/cpp1y/var-templ89.C
new file mode 100644
index 00000000000..5f98a95580c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ89.C
@@ -0,0 +1,32 @@
+// PR c++/125539
+// { dg-do compile { target c++14 } }
+
+struct A {};
+struct B { int i; };
+constexpr void foo () {}
+
+template<typename T>
+constexpr static A a1 = (foo (), A {});
+template<typename T>
+constexpr static A a2 = (A{}, A{});
+template<typename T>
+constexpr static A a3 = A{};
+template<typename T>
+constexpr static A a4 = {};
+template<typename T>
+constexpr static A a5{};
+template<typename T>
+constexpr static A a6 = (A{}, A{}, A{}, A{}, A{}, A{}, A{});
+template<int N>
+constexpr static B b1 = B{N};
+template<int N>
+constexpr static B b2 = (B{N}, B{N});
+
+template const A a1<int>;
+template const A a2<int>;
+template const A a3<int>;
+template const A a4<int>;
+template const A a5<int>;
+template const A a6<int>;
+template const B b1<42>;
+template const B b2<42>;
base-commit: ee7d0c7b4102b8ef0bcaa725c75e141248b774cb
--
2.54.0
