https://gcc.gnu.org/g:8a884140c2bcb738122e71d8d1c680f234de9843
commit r14-11679-g8a884140c2bcb738122e71d8d1c680f234de9843
Author: Jeremy Bettis <jbet...@google.com>
Date: Wed Apr 16 21:00:00 2025 -0700
libcpp: Fix incorrect line numbers in large files [PR108900]
This patch addresses an issue in the C preprocessor where incorrect
line number information is generated when processing files with a
large number of lines. The problem arises from improper handling
of location intervals in the line map, particularly when locations
exceed LINE_MAP_MAX_LOCATION_WITH_PACKED_RANGES.
By ensuring that the highest location is not decremented if it
would move to a different ordinary map, this fix resolves
the line number discrepancies observed in certain test cases.
This change improves the accuracy of line number reporting, benefiting
users relying on precise code coverage and debugging information.
Tested x86_64-linux.
libcpp/ChangeLog:
PR preprocessor/108900
* files.cc (_cpp_stack_file): Do not decrement highest_location
across distinct maps.
Signed-off-by: Jeremy Bettis <jbet...@google.com>
Signed-off-by: Yash Shinde <yash.shi...@windriver.com>
(cherry picked from commit d9b56c65a2697e0d7a6c0f15f1977803dc94579b)
Diff:
---
libcpp/files.cc | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/libcpp/files.cc b/libcpp/files.cc
index c61df339e207..5d53d7f6279c 100644
--- a/libcpp/files.cc
+++ b/libcpp/files.cc
@@ -1005,6 +1005,15 @@ _cpp_stack_file (cpp_reader *pfile, _cpp_file *file,
include_type type,
&& type < IT_DIRECTIVE_HWM
&& (pfile->line_table->highest_location
!= LINE_MAP_MAX_LOCATION - 1));
+
+ if (decrement && LINEMAPS_ORDINARY_USED (pfile->line_table))
+ {
+ const line_map_ordinary *map
+ = LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table);
+ if (map && map->start_location == pfile->line_table->highest_location)
+ decrement = false;
+ }
+
if (decrement)
pfile->line_table->highest_location--;
