From 1f5c80883efce5242d892eb771ebb60830d20e0f Mon Sep 17 00:00:00 2001 From: David Malcolm Date: Wed, 10 Feb 2021 14:33:10 -0500 Subject: [PATCH] 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. --- .../g++.dg/plugin/location-overflow-test-pr96391.c | 12 ++++++++++++ gcc/testsuite/g++.dg/plugin/plugin.exp | 2 ++ libcpp/line-map.c | 3 ++- 3 files changed, 16 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c diff --git a/gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c b/gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c new file mode 100644 index 00000000000..18169617c0c --- /dev/null +++ b/gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c @@ -0,0 +1,12 @@ +/* { dg-options "-fplugin-arg-location_overflow_plugin-value=0x60000001" } */ + +/* We use location_overflow_plugin.c, which injects the case that location_t + values have exceeded LINE_MAP_MAX_LOCATION_WITH_COLS, and hence no column + numbers are available. */ + +/* Verify that we're in column-less mode. */ +extern unknown_type test; /* { dg-error "-:'unknown_type' does not name a type" } */ + +#define CONST const +#define VOID void +typedef CONST VOID *PCVOID; diff --git a/gcc/testsuite/g++.dg/plugin/plugin.exp b/gcc/testsuite/g++.dg/plugin/plugin.exp index 80c5355fb5e..5cd4b4bff90 100644 --- a/gcc/testsuite/g++.dg/plugin/plugin.exp +++ b/gcc/testsuite/g++.dg/plugin/plugin.exp @@ -72,6 +72,8 @@ set plugin_test_list [list \ ../../gcc.dg/plugin/diagnostic-test-string-literals-2.c \ ../../gcc.dg/plugin/diagnostic-test-string-literals-3.c \ ../../gcc.dg/plugin/diagnostic-test-string-literals-4.c } \ + { ../../gcc.dg/plugin/location_overflow_plugin.c \ + location-overflow-test-pr96391.c } \ { show_template_tree_color_plugin.c \ show-template-tree-color.C \ show-template-tree-color-labels.C \ diff --git a/libcpp/line-map.c b/libcpp/line-map.c index 2432cd50d26..cccacf2fe5b 100644 --- a/libcpp/line-map.c +++ b/libcpp/line-map.c @@ -1417,7 +1417,8 @@ linemap_compare_locations (line_maps *set, if (l0 == l1 && pre_virtual_p - && post_virtual_p) + && post_virtual_p + && l0 <= LINE_MAP_MAX_LOCATION_WITH_COLS) { /* So pre and post represent two tokens that are present in a same macro expansion. Let's see if the token for pre was