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[C++ PATCH] PR c++/87075 - ICE with constexpr array initialization.
- From: Jason Merrill <jason at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 20 Sep 2018 13:07:45 -0400
- Subject: [C++ PATCH] PR c++/87075 - ICE with constexpr array initialization.
My patch of 2016-08-26 to avoid calling a trivial default constructor
introduced TARGET_EXPRs initialized with void_node to express trivial
initialization. But when this shows up in a VEC_INIT_EXPR, we weren't
prepared to handle it. Fixed by handling it explicitly in
cxx_eval_vec_init_1.
Tested x86_64-pc-linux-gnu, applying to trunk, and later 7 and 8.
* constexpr.c (cxx_eval_vec_init_1): Handle trivial initialization.
---
gcc/cp/constexpr.c | 3 +++
gcc/testsuite/g++.dg/cpp1y/constexpr-array6.C | 26 +++++++++++++++++++
gcc/cp/ChangeLog | 5 ++++
3 files changed, 34 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/constexpr-array6.C
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index aa33319875f..fdea769faa9 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -3034,6 +3034,9 @@ cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init,
{
/* Initializing an element using value or default initialization
we just pre-built above. */
+ if (init == void_node)
+ /* Trivial default-init, don't do anything to the CONSTRUCTOR. */
+ return ctx->ctor;
eltinit = cxx_eval_constant_expression (&new_ctx, init, lval,
non_constant_p, overflow_p);
reuse = i == 0;
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-array6.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-array6.C
new file mode 100644
index 00000000000..1f15bef8d0c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-array6.C
@@ -0,0 +1,26 @@
+// PR c++/87075
+// { dg-do compile { target c++14 } }
+
+template <typename T>
+struct vec
+{
+ struct { T y; } n;
+ vec() = default;
+};
+
+template <typename T>
+struct S
+{
+ vec<T> value[2];
+ template<typename U>
+ constexpr S(const U&);
+};
+
+template<typename T>
+template<typename X>
+constexpr S<T>::S(const X&)
+{
+ value[0] = vec<T>();
+}
+
+S<float>m(0);
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 75286d53fdb..c5072d53334 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2018-09-20 Jason Merrill <jason@redhat.com>
+
+ PR c++/87075 - ICE with constexpr array initialization.
+ * constexpr.c (cxx_eval_vec_init_1): Handle trivial initialization.
+
2018-09-19 Marek Polacek <polacek@redhat.com>
Add -Wclass-conversion.
base-commit: 51481b252ffe30a1daea491f62c687333efabc40
--
2.17.1