On Wed, Jul 19, 2023 at 03:24:10PM -0400, Jason Merrill wrote: > On 7/19/23 14:38, Marek Polacek wrote: > > On Wed, Jul 19, 2023 at 02:32:15PM -0400, Patrick Palka wrote: > > > On Wed, 19 Jul 2023, Marek Polacek wrote: > > > > > > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > > > > > LGTM. It might be preferable to check COMPLETE_TYPE_P in the caller > > > instead, so that we avoid inspecting CLASSTYPE_NON_AGGREGATE on an > > > incomplete class type, and so that the caller doesn't "commit" to > > > building an aggregate conversion. > > > > Perhaps. I wanted to avoid the call to build_user_type_conversion_1. > > I could add an early return to implicit_conversion_1 but I'd have to > > move some code around not to check COMPLETE_TYPE_P before complete_type. > > Maybe return NULL for the incomplete case here, rather than just skipping > reshape_init? > > /* Call reshape_init early to remove redundant braces. */ > if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) > && CLASS_TYPE_P (to) > && COMPLETE_TYPE_P (complete_type (to)) > && !CLASSTYPE_NON_AGGREGATE (to)) > { > expr = reshape_init (to, expr, complain); > if (expr == error_mark_node) > return NULL; > from = TREE_TYPE (expr); > } > > If that doesn't work, the patch is fine as-is.
It does work, with one test tweak (which I don't think is a regression): Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? -- >8 -- r13-1227 added an assert checking that the index in a CONSTRUCTOR is a FIELD_DECL. That's a reasonable assumption but in this case we never called reshape_init due to the type being incomplete, and so the index remained an identifier node: get_class_binding never got around to looking up the FIELD_DECL. We can avoid the crash by returning early in implicit_conversion_1; we'd return NULL anyway due to: if (i < CONSTRUCTOR_NELTS (ctor)) return NULL; in build_aggr_conv. PR c++/110114 gcc/cp/ChangeLog: * call.cc (implicit_conversion_1): Return early if the type isn't complete. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/initlist100.C: Adjust expected diagnostic. * g++.dg/cpp2a/desig28.C: New test. * g++.dg/cpp2a/desig29.C: New test. --- gcc/cp/call.cc | 19 +++++++++++-------- gcc/testsuite/g++.dg/cpp0x/initlist100.C | 4 ++-- gcc/testsuite/g++.dg/cpp2a/desig28.C | 17 +++++++++++++++++ gcc/testsuite/g++.dg/cpp2a/desig29.C | 10 ++++++++++ 4 files changed, 40 insertions(+), 10 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/desig28.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/desig29.C diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index b55230d98aa..673ec91d60e 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -2059,15 +2059,18 @@ implicit_conversion_1 (tree to, tree from, tree expr, bool c_cast_p, complain &= ~tf_error; /* Call reshape_init early to remove redundant braces. */ - if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) - && CLASS_TYPE_P (to) - && COMPLETE_TYPE_P (complete_type (to)) - && !CLASSTYPE_NON_AGGREGATE (to)) + if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) && CLASS_TYPE_P (to)) { - expr = reshape_init (to, expr, complain); - if (expr == error_mark_node) - return NULL; - from = TREE_TYPE (expr); + to = complete_type (to); + if (!COMPLETE_TYPE_P (to)) + return nullptr; + if (!CLASSTYPE_NON_AGGREGATE (to)) + { + expr = reshape_init (to, expr, complain); + if (expr == error_mark_node) + return nullptr; + from = TREE_TYPE (expr); + } } if (TYPE_REF_P (to)) diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist100.C b/gcc/testsuite/g++.dg/cpp0x/initlist100.C index 9d80a004c17..6865d34a6f9 100644 --- a/gcc/testsuite/g++.dg/cpp0x/initlist100.C +++ b/gcc/testsuite/g++.dg/cpp0x/initlist100.C @@ -2,9 +2,9 @@ // { dg-do compile { target c++11 } } namespace std { -template <class> class initializer_list; // { dg-message "declaration" } +template <class> class initializer_list; } template <typename T> struct B { B (std::initializer_list<T>); }; struct C { virtual int foo (); }; -struct D : C {} d { B<C> { D {} } }; // { dg-error "incomplete|no matching" } +struct D : C {} d { B<C> { D {} } }; // { dg-error "no matching" } diff --git a/gcc/testsuite/g++.dg/cpp2a/desig28.C b/gcc/testsuite/g++.dg/cpp2a/desig28.C new file mode 100644 index 00000000000..b63265fea51 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/desig28.C @@ -0,0 +1,17 @@ +// PR c++/110114 +// { dg-do compile { target c++20 } } + +struct A { + int a,b; +}; + +struct B; + +void foo(const A &) {} +void foo(const B &) {} + +int +main () +{ + foo({.a=0}); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/desig29.C b/gcc/testsuite/g++.dg/cpp2a/desig29.C new file mode 100644 index 00000000000..bd1a82b041d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/desig29.C @@ -0,0 +1,10 @@ +// PR c++/110114 +// { dg-do compile { target c++20 } } + +struct B; + +void foo(const B &) {} + +int main() { + foo({.a=0}); // { dg-error "invalid" } +} base-commit: b86c0fe327a5196a316bd698d12765b08de5dce7 -- 2.41.0