https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96391
--- Comment #20 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>: https://gcc.gnu.org/g:1f5c80883efce5242d892eb771ebb60830d20e0f commit r11-7179-g1f5c80883efce5242d892eb771ebb60830d20e0f Author: David Malcolm <dmalc...@redhat.com> Date: Wed Feb 10 14:33:10 2021 -0500 libcpp: fix ICE comparing macro locations without column info [PR96391] PR preprocessor/96391 describes an ICE in the C++ frontend on: #define CONST const #define VOID void typedef CONST VOID *PCVOID; where the typedef line occurs after enough code has been compiled that location_t values are beyond LINE_MAP_MAX_LOCATION_WITH_COLS, and hence no column numbers are available. The issue occurs in linemap_compare_locations when comparing the locations of the "const" and "void" tokens. Upon resolving the LRK_MACRO_EXPANSION_POINT, both have the same location_t, the line of the "typedef" (with no column), and so the l0 == l1 clause is triggered, but they are not from the same macro expansion, leading first_map_in_common to return NULL and triggering the "abort" condition. This patch fixes the issue by checking when the two macro expansion point location_t values are equal that the value <= LINE_MAP_MAX_LOCATION_WITH_COLS and thus has column information, fixing the issue. gcc/testsuite/ChangeLog: PR preprocessor/96391 * g++.dg/plugin/location-overflow-test-pr96391.c: New test. * g++.dg/plugin/plugin.exp (plugin_test_list): Add it, using the location_overflow_plugin.c from gcc.dg/plugin. libcpp/ChangeLog: PR preprocessor/96391 * line-map.c (linemap_compare_locations): Require that the location be <= LINE_MAP_MAX_LOCATION_WITH_COLS when treating locations as coming from the same macro expansion.
