[C++ PATCH] PR c++/91930 - ICE with constrained inherited default ctor.
Jason Merrill
jason@redhat.com
Mon Oct 14 20:13:00 GMT 2019
The testcase was crashing because lazily_declare_fn was failing to add a
defaulted constructor, because the implicit declaration was less constrained
than the inherited default constructor. But when we have an inherited
constructor, we shouldn't be trying to declare a default constructor in the
first place, because it counts as "a user-declared constructor". With that
fixed I needed to adjust a couple of inherited constructor testcases that
previously had been diagnosing the default constructor as deleted rather
than not declared.
Tested x86_64-pc-linux-gnu, applying to trunk.
* name-lookup.c (do_class_using_decl): Set TYPE_HAS_USER_CONSTRUCTOR
for inherited constructor.
---
gcc/cp/name-lookup.c | 1 +
gcc/testsuite/g++.dg/cpp0x/inh-ctor5.C | 4 ++--
gcc/testsuite/g++.dg/cpp1z/inh-ctor22.C | 4 ++--
gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor6.C | 12 ++++++++++++
4 files changed, 17 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor6.C
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 57ab129c9ec..9352ce5da0b 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -4613,6 +4613,7 @@ do_class_using_decl (tree scope, tree name)
maybe_warn_cpp0x (CPP0X_INHERITING_CTORS);
name = ctor_identifier;
CLASSTYPE_NON_AGGREGATE (current_class_type) = true;
+ TYPE_HAS_USER_CONSTRUCTOR (current_class_type) = true;
}
/* Cannot introduce a constructor name. */
diff --git a/gcc/testsuite/g++.dg/cpp0x/inh-ctor5.C b/gcc/testsuite/g++.dg/cpp0x/inh-ctor5.C
index d0038c16a14..673b6380504 100644
--- a/gcc/testsuite/g++.dg/cpp0x/inh-ctor5.C
+++ b/gcc/testsuite/g++.dg/cpp0x/inh-ctor5.C
@@ -6,13 +6,13 @@ struct B1 {
struct B2 {
B2(double) { }
};
-struct D1 : B1 { // { dg-error "no match" }
+struct D1 : B1 {
using B1::B1; // implicitly declares D1(int)
int x;
};
void test() {
D1 d(6); // OK: d.x is not initialized
- D1 e; // { dg-error "deleted" } D1 has no default constructor
+ D1 e; // { dg-error "no match" } D1 has no default constructor
}
struct D2 : B2 {
using B2::B2; // { dg-error "B1::B1" }
diff --git a/gcc/testsuite/g++.dg/cpp1z/inh-ctor22.C b/gcc/testsuite/g++.dg/cpp1z/inh-ctor22.C
index 02ec58a3e8e..98336a158c1 100644
--- a/gcc/testsuite/g++.dg/cpp1z/inh-ctor22.C
+++ b/gcc/testsuite/g++.dg/cpp1z/inh-ctor22.C
@@ -12,7 +12,7 @@ struct B2 {
int get();
-struct D1 : B1 { // { dg-message "B1::B1" }
+struct D1 : B1 {
using B1::B1; // inherits B1(int, ...)
int x;
int y = get();
@@ -22,7 +22,7 @@ void test() {
D1 d(2, 3, 4); // OK: B1 is initialized by calling B1(2, 3, 4),
// then d.x is default-initialized (no initialization is performed),
// then d.y is initialized by calling get()
- D1 e; // { dg-error "" } D1 has a deleted default constructor
+ D1 e; // { dg-error "" } D1 has no default constructor
}
struct D2 : B2 {
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor6.C b/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor6.C
new file mode 100644
index 00000000000..c92d6ac774c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-inherit-ctor6.C
@@ -0,0 +1,12 @@
+// PR c++/91930
+// { dg-do compile { target c++2a } }
+
+template <typename T> struct basic_mixin {
+ basic_mixin() requires true;
+};
+
+struct mixin : basic_mixin<int> {
+ using basic_mixin<int>::basic_mixin;
+};
+
+mixin m;
base-commit: a8bf45f436ead5d31db39e9a9578429524d70a2f
--
2.18.1
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