On 10/14/20 9:56 AM, Patrick Palka via Gcc-patches wrote: > The r11-3266 patch that added macro support to -Wmisleading-indentation > accidentally suppressed the column-tracking diagnostic in > get_visual_column in some cases, e.g. in the location-overflow-test-1.c > testcase. > > More generally, when all three tokens are on the same line and we've run > out of locations with column info, then their location_t values will be > equal, and we exit early from should_warn_for_misleading_indentation due > to the new check > > /* Give up if the loci are not all distinct. */ > if (guard_loc == body_loc || body_loc == next_stmt_loc) > return false; > > before we ever call get_visual_column. > > [ This new check is needed to detect and give up on analyzing code > fragments where exactly two out of the three tokens come from the same > macro expansion, e.g. > > #define MACRO \ > if (a) \ > foo (); > > MACRO; bar (); > > Here, guard_loc and body_loc will be equal and point to the macro > expansion point. The heuristics the warning uses are not really valid > in scenarios like these. ] > > In order to restore the column-tracking diagnostic, this patch moves the > the diagnostic code out from get_visual_column to earlier in > should_warn_for_misleading_indentation. Moreover, it tests the three > location_t values for a zero column all at once, which I suppose should > make us issue the diagnostic more consistently. > > Tested on x86_64-pc-linux-gnu, does this look OK to commit? > > gcc/c-family/ChangeLog: > > PR testsuite/97117 > * c-indentation.c (get_visual_column): Remove location_t > parameter. Move the column-tracking diagnostic code from here > to ... > (should_warn_for_misleading_indentation): ... here, before the > early exit for when the loci are not all distinct. Don't pass a > location_t argument to get_visual_column. > (assert_get_visual_column_succeeds): Don't pass a location_t > argument to get_visual_column. > (assert_get_visual_column_fails): Likewise.
OK. jeff
