From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2122) id 0E6DA385E01D; Thu, 29 Sep 2022 17:52:26 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0E6DA385E01D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1664473946; bh=PpHiTg4wQG6AxF23/KM3qudENVj41VpWRPSdf23+7zs=; h=From:To:Subject:Date:From; b=EBe4U40Yx+YPMmlZiH8Oc1YZQ8cVcnRodVL5EsVlDP7gdYxFnu/Ri+MRt6zGwuAC5 /hwK6QHWZ6zga2As7Pyrg9ciFshXYiBYveB8i41vQZUGo56egMkzbsLuOaYyh9d0W8 zxI91kKct0mVzlkNzYuCUxX/DL+/uCnDUZT0ArG4= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jason Merrill To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-2964] c++: fix class-valued ?: extension X-Act-Checkin: gcc X-Git-Author: Jason Merrill X-Git-Refname: refs/heads/master X-Git-Oldrev: 32b2eb59fb904926eff77811e08766a8ae6804a7 X-Git-Newrev: bbdb5612f6661f2c64b0c0f1d2291cb59fde2b40 Message-Id: <20220929175226.0E6DA385E01D@sourceware.org> Date: Thu, 29 Sep 2022 17:52:26 +0000 (GMT) List-Id: https://gcc.gnu.org/g:bbdb5612f6661f2c64b0c0f1d2291cb59fde2b40 commit r13-2964-gbbdb5612f6661f2c64b0c0f1d2291cb59fde2b40 Author: Jason Merrill Date: Fri Sep 23 09:07:22 2022 -0400 c++: fix class-valued ?: extension When the gimplifier encounters the same TARGET_EXPR twice, it evaluates TARGET_EXPR_INITIAL the first time and clears it so that the later evaluation is just the temporary. With this testcase, using the extension to treat an omitted middle operand as repeating the first operand, that led to doing a bitwise copy of the S(1) temporary on return rather than properly calling the copy constructor. We can't use S(1) to initialize the return value here anyway, because we need to materialize it into a temporary so we can convert it to bool and determine which arm we're evaluating. So let's just treat the middle operand as an xvalue. PR c++/93046 gcc/cp/ChangeLog: * call.cc (build_conditional_expr): For a?:c extension, treat a reused class prvalue as an xvalue. gcc/testsuite/ChangeLog: * g++.dg/ext/cond4.C: Add runtime test. Diff: --- gcc/cp/call.cc | 5 +++++ gcc/testsuite/g++.dg/ext/cond4.C | 17 ++++++++++++++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 9fad3cb950b..bd04a1d309a 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -5402,6 +5402,11 @@ build_conditional_expr (const op_location_t &loc, arg1 = cp_stabilize_reference (arg1); arg2 = arg1 = prevent_lifetime_extension (arg1); } + else if (TREE_CODE (arg1) == TARGET_EXPR) + /* arg1 can't be a prvalue result of the conditional + expression, since it needs to be materialized for the + conversion to bool, so treat it as an xvalue in arg2. */ + arg2 = move (TARGET_EXPR_SLOT (arg1)); else arg2 = arg1 = cp_save_expr (arg1); } diff --git a/gcc/testsuite/g++.dg/ext/cond4.C b/gcc/testsuite/g++.dg/ext/cond4.C index d2853f40387..86993306aa5 100644 --- a/gcc/testsuite/g++.dg/ext/cond4.C +++ b/gcc/testsuite/g++.dg/ext/cond4.C @@ -1,10 +1,14 @@ // PR c++/93046 -// { dg-do compile } +// { dg-do run } // { dg-options "" } +int c; + struct S { - S (int); - operator bool (); + int i; + S (int i) : i(i) { ++c; } + S (const S &s): i(s.i) { ++c; } + operator bool () { return i; } }; S @@ -12,3 +16,10 @@ foo () { return S (1) ? : S (2); } + +int main() +{ + S s = foo(); + if (s.i != 1 || c != 2) + __builtin_abort (); +}