https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99230
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:9f59cb7cac009f3c6eba81eb09714699b9ac9f8d commit r11-7750-g9f59cb7cac009f3c6eba81eb09714699b9ac9f8d Author: Jakub Jelinek <ja...@redhat.com> Date: Sat Mar 20 17:02:06 2021 +0100 c-family: Fix PR94272 -fcompare-debug issue even for C [PR99230] The following testcase results in -fcompare-debug failure. The problem is the similar like in PR94272 https://gcc.gnu.org/pipermail/gcc-patches/2020-March/542562.html When genericizing, with -g0 we have just a TREE_SIDE_EFFECTS DO_STMT in a branch of if, while with -g we have that wrapped into TREE_SIDE_EFFECTS STATEMENT_LIST containing DEBUG_BEGIN_STMT and that DO_STMT. The do loop is empty with 0 condition, so c_genericize_control_stmt turns it into an empty statement (without TREE_SIDE_EFFECTS). For -g0 that means that suddenly the if branch doesn't have side effects and is expanded differently. But with -g we still have TREE_SIDE_EFFECTS STATEMENT_LIST containing DEBUG_BEGIN_STMT and non-TREE_SIDE_EFFECTS stmt. The following patch fixes that by detecting this case and removing TREE_SIDE_EFFECTS. And, so that we don't duplicate the same code, changes the C++ FE to just call the c_genericize_control_stmt function that can now handle it. 2021-03-20 Jakub Jelinek <ja...@redhat.com> PR debug/99230 * c-gimplify.c (c_genericize_control_stmt): Handle STATEMENT_LIST. * cp-gimplify.c (cp_genericize_r) <case STATEMENT_LIST>: Remove special code, instead call c_genericize_control_stmt. * gcc.dg/pr99230.c: New test.
