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.
---
gcc/c-family/c-indentation.c | 70 ++++++++++++++++++------------------
1 file changed, 34 insertions(+), 36 deletions(-)
diff --git a/gcc/c-family/c-indentation.c b/gcc/c-family/c-indentation.c
index 8b88a8adc7c..836a524f266 100644
--- a/gcc/c-family/c-indentation.c
+++ b/gcc/c-family/c-indentation.c
@@ -45,36 +45,11 @@ next_tab_stop (unsigned int vis_column, unsigned int
tab_width)
on the line (up to or before EXPLOC). */
static bool
-get_visual_column (expanded_location exploc, location_t loc,
+get_visual_column (expanded_location exploc,
unsigned int *out,
unsigned int *first_nws,
unsigned int tab_width)
{
- /* PR c++/68819: if the column number is zero, we presumably
- had a location_t > LINE_MAP_MAX_LOCATION_WITH_COLS, and so
- we have no column information.
- Act as if no conversion was possible, triggering the
- error-handling path in the caller. */
- if (!exploc.column)
- {
- static bool issued_note = false;
- if (!issued_note)
- {
- /* Notify the user the first time this happens. */
- issued_note = true;
- inform (loc,
- "%<-Wmisleading-indentation%> is disabled from this point"
- " onwards, since column-tracking was disabled due to"
- " the size of the code/headers");
- if (!flag_large_source_files)
- inform (loc,
- "adding %<-flarge-source-files%> will allow for more"
- " column-tracking support, at the expense of compilation"
- " time and memory");
- }
- return false;
- }
-
char_span line = location_get_source_line (exploc.file, exploc.line);
if (!line)
return false;
@@ -325,14 +300,37 @@ should_warn_for_misleading_indentation (const
token_indent_info &guard_tinfo,
NULL);
}
- /* Give up if the loci are not all distinct. */
- if (guard_loc == body_loc || body_loc == next_stmt_loc)
- return false;
-
expanded_location body_exploc = expand_location (body_loc);
expanded_location next_stmt_exploc = expand_location (next_stmt_loc);
expanded_location guard_exploc = expand_location (guard_loc);
+ /* PR c++/68819: if the column number is zero, we presumably
+ had a location_t > LINE_MAP_MAX_LOCATION_WITH_COLS, and so
+ we have no column information. */
+ if (!guard_exploc.column || !body_exploc.column || !next_stmt_exploc.column)
+ {
+ static bool issued_note = false;
+ if (!issued_note)
+ {
+ /* Notify the user the first time this happens. */
+ issued_note = true;
+ inform (guard_loc,
+ "%<-Wmisleading-indentation%> is disabled from this point"
+ " onwards, since column-tracking was disabled due to"
+ " the size of the code/headers");
+ if (!flag_large_source_files)
+ inform (guard_loc,
+ "adding %<-flarge-source-files%> will allow for more"
+ " column-tracking support, at the expense of compilation"
+ " time and memory");
+ }
+ return false;
+ }
+
+ /* Give up if the loci are not all distinct. */
+ if (guard_loc == body_loc || body_loc == next_stmt_loc)
+ return false;
+
const unsigned int tab_width = global_dc->tabstop;
/* They must be in the same file. */
@@ -378,7 +376,7 @@ should_warn_for_misleading_indentation (const
token_indent_info &guard_tinfo,
gcc_assert (guard_exploc.line == next_stmt_exploc.line);
unsigned int guard_vis_column;
unsigned int guard_line_first_nws;
- if (!get_visual_column (guard_exploc, guard_loc,
+ if (!get_visual_column (guard_exploc,
&guard_vis_column,
&guard_line_first_nws, tab_width))
return false;
@@ -438,15 +436,15 @@ should_warn_for_misleading_indentation (const
token_indent_info &guard_tinfo,
the case for input files containing #line directives, and these
are often for autogenerated sources (e.g. from .md files), where
it's not clear that it's meaningful to look at indentation. */
- if (!get_visual_column (next_stmt_exploc, next_stmt_loc,
+ if (!get_visual_column (next_stmt_exploc,
&next_stmt_vis_column,
&next_stmt_line_first_nws, tab_width))
return false;
- if (!get_visual_column (body_exploc, body_loc,
+ if (!get_visual_column (body_exploc,
&body_vis_column,
&body_line_first_nws, tab_width))
return false;
- if (!get_visual_column (guard_exploc, guard_loc,
+ if (!get_visual_column (guard_exploc,
&guard_vis_column,
&guard_line_first_nws, tab_width))
return false;
@@ -701,7 +699,7 @@ assert_get_visual_column_succeeds (const location &loc,
exploc.sysp = false;
unsigned int actual_visual_column;
unsigned int actual_first_nws;
- bool result = get_visual_column (exploc, UNKNOWN_LOCATION,
+ bool result = get_visual_column (exploc,
&actual_visual_column,
&actual_first_nws, tab_width);
ASSERT_TRUE_AT (loc, result);
@@ -739,7 +737,7 @@ assert_get_visual_column_fails (const location &loc,
exploc.sysp = false;
unsigned int actual_visual_column;
unsigned int actual_first_nws;
- bool result = get_visual_column (exploc, UNKNOWN_LOCATION,
+ bool result = get_visual_column (exploc,
&actual_visual_column,
&actual_first_nws, tab_width);
ASSERT_FALSE_AT (loc, result);
--
2.29.0.rc0
