https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90996
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:23f1f679141bbb4720ca195cb758605dc017b7fd commit r10-7587-g23f1f679141bbb4720ca195cb758605dc017b7fd Author: Patrick Palka <ppa...@redhat.com> Date: Mon Apr 6 14:05:44 2020 -0400 c++: Fix usage of CONSTRUCTOR_PLACEHOLDER_BOUNDARY inside array initializers [PR90996] This PR reports that ever since the introduction of the CONSTRUCTOR_PLACEHOLDER_BOUNDARY flag, we are sometimes failing to resolve PLACEHOLDER_EXPRs inside array initializers that refer to some inner constructor. In the testcase in the PR, we have as the initializer for "S c[];" the following {{.a=(int &) &_ZGR1c_, .b={*(&<PLACEHOLDER_EXPR struct S>)->a}}} where CONSTRUCTOR_PLACEHOLDER_BOUNDARY is set on the middle constructor. When calling replace_placeholders from store_init_value, we pass the entire initializer to it, and as a result we fail to resolve the PLACEHOLDER_EXPR within due to the CONSTRUCTOR_PLACEHOLDER_BOUNDARY flag on the middle constructor blocking replace_placeholders_r from reaching it. To fix this, we could perhaps either call replace_placeholders in more places, or we could change where we set CONSTRUCTOR_PLACEHOLDER_BOUNDARY. This patch takes this latter approach -- when building up an array initializer, we now bubble any CONSTRUCTOR_PLACEHOLDER_BOUNDARY flag from the element initializers up to the array initializer so that the boundary doesn't later impede us when we call replace_placeholders from store_init_value. Besides fixing the kind of code like in the testcase, this shouldn't cause any other differences in PLACEHOLDER_EXPR resolution because we don't create or use PLACEHOLDER_EXPRs of array type in the frontend, as far as I can tell. gcc/cp/ChangeLog: PR c++/90996 * tree.c (replace_placeholders): Look through all handled components, not just COMPONENT_REFs. * typeck2.c (process_init_constructor_array): Propagate CONSTRUCTOR_PLACEHOLDER_BOUNDARY up from each element initializer to the array initializer. gcc/testsuite/ChangeLog: PR c++/90996 * g++.dg/cpp1y/pr90996.C: New test.
