This patch fixes the false positive seen from -Wmisleading-indentation
on this code:
if (v == 2)
{
res = 27;
} else
{
res = 18;
}
return res;
^ FALSE POSITIVE HERE
along with similar code seen when I tested it with linux-4.0.3.
The patch adds a reject for the case where the guard ("else" in
the above example) is more indented than the things it guards.
Doing so uncovered an issue with this testcase:
#define FOR_EACH(VAR, START, STOP) for ((VAR) = (START); (VAR) < (STOP);
(VAR++)) /* { dg-message "36: ...this 'for' clause, but it is not" } */
void fn_15 (void)
{
int i;
FOR_EACH (i, 0, 10) /* { dg-message "3: in expansion of macro" } */
foo (i);
bar (i, i); /* { dg-warning "statement is indented as if it were guarded
by..." } */
}
#undef FOR_EACH
which would then fail to report the warning, due to it using the
location of the "for" in the definition of macro FOR_EACH, rather than
the location of the FOR_EACH (i, 0, 10). The fix for this is to use
expand_location to get file/line/col of each thing, rather than
expand_location_to_spelling_point.
With that, all testcases in Wmisleading-indentation.c pass (including
the new ones posted in
https://gcc.gnu.org/ml/gcc-patches/2015-05/msg01846.html ).
OK for trunk if it passes bootstrap®rest? (only tested with
make check-gcc RUNTESTFLAGS="dg.exp=Wmisleading-indentation.c"
make check-g++ RUNTESTFLAGS="dg.exp=Wmisleading-indentation.c"
so far)
gcc/c-family/ChangeLog:
PR c/66220:
* c-indentation.c (should_warn_for_misleading_indentation): Use
expand_location rather than expand_location_to_spelling_point.
Don't warn if the guarding statement is more indented than the
next/body stmts.
gcc/testsuite/ChangeLog:
PR c/66220:
* c-c++-common/Wmisleading-indentation.c (fn_35): New.
(fn_36): New.
---
gcc/c-family/c-indentation.c | 26 ++++++++++-----
.../c-c++-common/Wmisleading-indentation.c | 38 ++++++++++++++++++++++
2 files changed, 56 insertions(+), 8 deletions(-)
diff --git a/gcc/c-family/c-indentation.c b/gcc/c-family/c-indentation.c
index 9aeebae..1e3a6d8 100644
--- a/gcc/c-family/c-indentation.c
+++ b/gcc/c-family/c-indentation.c
@@ -230,10 +230,8 @@ should_warn_for_misleading_indentation (location_t
guard_loc,
if (next_tok_type == CPP_SEMICOLON)
return false;
- expanded_location body_exploc
- = expand_location_to_spelling_point (body_loc);
- expanded_location next_stmt_exploc
- = expand_location_to_spelling_point (next_stmt_loc);
+ expanded_location body_exploc = expand_location (body_loc);
+ expanded_location next_stmt_exploc = expand_location (next_stmt_loc);
/* They must be in the same file. */
if (next_stmt_exploc.file != body_exploc.file)
@@ -257,8 +255,7 @@ should_warn_for_misleading_indentation (location_t
guard_loc,
^ DON'T WARN HERE. */
if (next_stmt_exploc.line == body_exploc.line)
{
- expanded_location guard_exploc
- = expand_location_to_spelling_point (guard_loc);
+ expanded_location guard_exploc = expand_location (guard_loc);
if (guard_exploc.file != body_exploc.file)
return true;
if (guard_exploc.line < body_exploc.line)
@@ -299,6 +296,15 @@ should_warn_for_misleading_indentation (location_t
guard_loc,
#endif
bar ();
^ DON'T WARN HERE
+
+ if (flag) {
+ foo ();
+ } else
+ {
+ bar ();
+ }
+ baz ();
+ ^ DON'T WARN HERE
*/
if (next_stmt_exploc.line > body_exploc.line)
{
@@ -319,14 +325,18 @@ should_warn_for_misleading_indentation (location_t
guard_loc,
/* Don't warn if they aren't aligned on the same column
as the guard itself (suggesting autogenerated code that
doesn't bother indenting at all). */
- expanded_location guard_exploc
- = expand_location_to_spelling_point (guard_loc);
+ expanded_location guard_exploc = expand_location (guard_loc);
unsigned int guard_vis_column;
if (!get_visual_column (guard_exploc, &guard_vis_column))
return false;
if (guard_vis_column == body_vis_column)
return false;
+ /* PR 66220: Don't warn if the guarding statement is more
+ indented than the next/body stmts. */
+ if (guard_vis_column > body_vis_column)
+ return false;
+
/* Don't warn if there is multiline preprocessor logic between
the two statements. */
if (detect_preprocessor_logic (body_exploc, next_stmt_exploc))
diff --git a/gcc/testsuite/c-c++-common/Wmisleading-indentation.c
b/gcc/testsuite/c-c++-common/Wmisleading-indentation.c
index 6363d71..443e3dd 100644
--- a/gcc/testsuite/c-c++-common/Wmisleading-indentation.c
+++ b/gcc/testsuite/c-c++-common/Wmisleading-indentation.c
@@ -653,3 +653,41 @@ void fn_34_indent_linux_style(void)
}
foo(5);
}
+
+/* PR 66220. */
+int fn_35 (int v)
+{
+ int res = 28;
+
+ if (v == 2)
+ {
+ res = 27;
+ } else
+ {
+ res = 18;
+ }
+ return res;
+}
+
+/* This variant of K&R-style formatting (in the presence of conditional
+ compilation) shouldn't lead to a warning.
+
+ Based on false positive seen with r223098 when compiling
+ linux-4.0.3:arch/x86/crypto/aesni-intel_glue.c:aesni_init. */
+void
+fn_36 (void)
+{
+#if 1 /* e.g. some configuration variable. */
+ if (flagA) {
+ foo(0);
+ foo(1);
+ foo(2);
+ } else
+#endif
+ {
+ foo(3);
+ foo(4);
+ foo(5);
+ }
+ foo(6); /* We shouldn't warn here. */
+}
--
1.8.5.3
