* [patch] PR c++/65295: Allow return-value optimization for constexpr's
@ 2015-03-03 18:17 Aldy Hernandez
0 siblings, 0 replies; only message in thread
From: Aldy Hernandez @ 2015-03-03 18:17 UTC (permalink / raw)
To: gcc-patches, jason merrill
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In constexpr handling, we can request an rval for a return-value both by
an invisible reference and by virtue of named return value optimization.
Fixed by removing the assert.
Approved by Jason off-line.
Committed to mainline.
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commit 1a8fdc708eeab70adc237193febf5f8db1eab995
Author: Aldy Hernandez <aldyh@redhat.com>
Date: Tue Mar 3 10:13:14 2015 -0800
PR c++/65295
* constexpr.c (cxx_eval_constant_expression): Remove assert in
RESULT_DECL handling.
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index f7e8ce9..1b5f50c 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -2955,8 +2955,8 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
if (lval)
return t;
/* We ask for an rvalue for the RESULT_DECL when indirecting
- through an invisible reference. */
- gcc_assert (DECL_BY_REFERENCE (t));
+ through an invisible reference, or in named return value
+ optimization. */
return (*ctx->values->get (t));
case VAR_DECL:
diff --git a/gcc/testsuite/g++.dg/pr65295.C b/gcc/testsuite/g++.dg/pr65295.C
new file mode 100644
index 0000000..c189ee1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr65295.C
@@ -0,0 +1,20 @@
+// { dg-do compile }
+// { dg-options "-std=c++1y" }
+
+struct arr {
+ constexpr arr() : elem() { }
+ char elem[17];
+};
+
+constexpr
+arr f()
+{
+ arr result;
+ return result;
+}
+
+constexpr arr a { f() };
+
+int main()
+{
+}
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2015-03-03 18:17 [patch] PR c++/65295: Allow return-value optimization for constexpr's Aldy Hernandez
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