From bb1f0b50abbfa01e0ed720a5225a11aa7af32a89 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Fri, 8 Jan 2021 10:11:25 -0500 Subject: [PATCH] c++: ICE with constexpr call that returns a PMF [PR98551] We shouldn't do replace_result_decl after evaluating a call that returns a PMF because PMF temporaries aren't wrapped in a TARGET_EXPR (and so we can't trust ctx->object), and PMF initializers can't be self-referential anyway, so replace_result_decl would always be a no-op. To that end, this patch changes the relevant AGGREGATE_TYPE_P test to CLASS_TYPE_P, which should rule out PMFs (as well as arrays, which we can't return and therefore won't see here). This fixes an ICE from the sanity check in replace_result_decl in the below testcase during constexpr evaluation of the call f() in the initializer g(f()). gcc/cp/ChangeLog: PR c++/98551 * constexpr.c (cxx_eval_call_expression): Check CLASS_TYPE_P instead of AGGREGATE_TYPE_P before calling replace_result_decl. gcc/testsuite/ChangeLog: PR c++/98551 * g++.dg/cpp0x/constexpr-pmf2.C: New test. --- gcc/cp/constexpr.c | 2 +- gcc/testsuite/g++.dg/cpp0x/constexpr-pmf2.C | 9 +++++++++ 2 files changed, 10 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-pmf2.C diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 4a5e6384da6..9dddc53ca52 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -2790,7 +2790,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, /* Rewrite all occurrences of the function's RESULT_DECL with the current object under construction. */ if (!*non_constant_p && ctx->object - && AGGREGATE_TYPE_P (TREE_TYPE (res)) + && CLASS_TYPE_P (TREE_TYPE (res)) && !is_empty_class (TREE_TYPE (res))) if (replace_result_decl (&result, res, ctx->object)) cacheable = false; diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-pmf2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-pmf2.C new file mode 100644 index 00000000000..a76e712afe1 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-pmf2.C @@ -0,0 +1,9 @@ +// PR c++/98551 +// { dg-do compile { target c++11 } } + +struct A {}; +struct B { int t(); }; +using pmf = decltype(&B::t); +constexpr pmf f() { return &B::t; } +constexpr A g(pmf) { return {}; }; +constexpr A x = g(f()); -- 2.34.1