diagnostic_show_locus can sometimes do the wrong thing when handling
expressions built up from macros.
PR c++/70105 (currently marked as a P3 regression) has an example of
a diagnostic where over 500 lines of irrelevant source are printed,
and underlined, giving >1000 lines of useless spew to stderr.
This patch adds extra sanitization to diagnostic-show-locus.c, so that
we only attempt to print underlines and secondary locations if such
locations are "sufficiently sane" relative to the primary location
of a diagnostic.
This "sufficiently sane" condition is implemented by a new helper
function compatible_locations_p, which requires such locations to
have the same macro expansion hierarchy as the primary location,
using linemap_macro_map_loc_unwind_toward_spelling, effectively
mimicing the expansion performed by LRK_SPELLING_LOCATION.
This may be too strong a condition, but it effectively fixes
PR c++/70105, without removing any underlines in my testing.
Successfully bootstrapped®rtested in combination with the previous
patch on x86_64-pc-linux-gnu; adds 15 new PASS results to g++.sum
and 4 new PASS results to gcc.sum.
gcc/ChangeLog:
PR c/68473
PR c++/70105
* diagnostic-show-locus.c (compatible_locations_p): New function.
(layout::layout): Sanitize ranges using compatible_locations_p.
gcc/testsuite/ChangeLog:
PR c/68473
PR c++/70105
* g++.dg/diagnostic/pr70105.C: New test.
* gcc.dg/plugin/diagnostic-test-expressions-1.c (foo): New decl.
(test_multiple_ordinary_maps): New test function.
libcpp/ChangeLog:
PR c/68473
PR c++/70105
* line-map.c (linemap_macro_map_loc_unwind_toward_spelling): Move
decl...
* include/line-map.h
(linemap_macro_map_loc_unwind_toward_spelling): ...here,
converting from static to extern.
From-SVN: r234088
b4f3232d69