From ef529765234bea7893bd56f3ab3a2da7695f6b21 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Wed, 8 Apr 2020 23:59:30 -0400 Subject: [PATCH] c++: constexpr static data member instantiation [PR94523] Here due to my recent change to store_init_value we were expanding the initializer of aw knowing that we were initializing aw. When cxx_eval_call_expression finished the constructor, it wanted to look up the value of aw to set TREE_READONLY on it, but we haven't set DECL_INITIAL yet, so decl_constant_value tried to instantiate the initializer again. And infinite recursion. Stopped by optimizing the case of asking for the value of ctx->object, which is ctx->value. It also would have worked to look in the values hash table, so let's move that up before decl_constant_value as well. gcc/cp/ChangeLog 2020-04-09 Jason Merrill PR c++/94523 * constexpr.c (cxx_eval_constant_expression) [VAR_DECL]: Look at ctx->object and ctx->global->values first. --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/constexpr.c | 13 +++++++++---- gcc/testsuite/g++.dg/cpp1y/constexpr-static1.C | 10 ++++++++++ 3 files changed, 25 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1y/constexpr-static1.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index cdd9b52915a..49246e8fa2d 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-04-09 Jason Merrill + + PR c++/94523 + * constexpr.c (cxx_eval_constant_expression) [VAR_DECL]: Look at + ctx->object and ctx->global->values first. + 2020-04-09 Marek Polacek PR c++/93790 diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 96497ab85d7..5793430c88d 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -5485,6 +5485,15 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, CONST_DECL for aggregate constants. */ if (lval) return t; + else if (t == ctx->object) + return ctx->ctor; + if (VAR_P (t)) + if (tree *p = ctx->global->values.get (t)) + if (*p != NULL_TREE) + { + r = *p; + break; + } if (COMPLETE_TYPE_P (TREE_TYPE (t)) && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) { @@ -5499,10 +5508,6 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, if (TREE_CODE (r) == TARGET_EXPR && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) r = TARGET_EXPR_INITIAL (r); - if (VAR_P (r)) - if (tree *p = ctx->global->values.get (r)) - if (*p != NULL_TREE) - r = *p; if (DECL_P (r)) { if (!ctx->quiet) diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-static1.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-static1.C new file mode 100644 index 00000000000..f39ed216fae --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-static1.C @@ -0,0 +1,10 @@ +// PR c++/94523 +// { dg-do compile { target c++14 } } + +template using b = a; +struct d { + char ao; + template constexpr d(ap) : ao{} {} +}; +template struct e { static constexpr auto aw = d(au...); }; +template b ax(e<1>::aw); -- 2.30.2