diff options
| author | Nick Desaulniers <nick.desaulniers@gmail.com> | 2020-02-23 11:34:49 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-03-04 10:28:08 -0300 |
| commit | c395c3553d6870541f1c283479aea2a6f26364d5 (patch) | |
| tree | 1e02ad87d273396c99079ec276634f1e95b21777 /tools/perf/builtin-diff.c | |
| parent | b95b4d5ef061806fde07a6a3255e6c07f4fed0d3 (diff) | |
perf diff: Fix undefined string comparison spotted by clang's -Wstring-compare
clang warns:
util/block-info.c:298:18: error: result of comparison against a string
literal is unspecified (use an explicit string comparison function
instead) [-Werror,-Wstring-compare]
if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) {
^ ~~~~~~~~~~~~~~~
util/block-info.c:298:51: error: result of comparison against a string
literal is unspecified (use an explicit string comparison function
instead) [-Werror,-Wstring-compare]
if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) {
^ ~~~~~~~~~~~~~~~
util/block-info.c:298:18: error: result of comparison against a string
literal is unspecified (use an explicit string
comparison function instead) [-Werror,-Wstring-compare]
if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) {
^ ~~~~~~~~~~~~~~~
util/block-info.c:298:51: error: result of comparison against a string
literal is unspecified (use an explicit string comparison function
instead) [-Werror,-Wstring-compare]
if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) {
^ ~~~~~~~~~~~~~~~
util/map.c:434:15: error: result of comparison against a string literal
is unspecified (use an explicit string comparison function instead)
[-Werror,-Wstring-compare]
if (srcline != SRCLINE_UNKNOWN)
^ ~~~~~~~~~~~~~~~
Reviewer Notes:
Looks good to me. Some more context:
https://clang.llvm.org/docs/DiagnosticsReference.html#wstring-compare
The spec says:
J.1 Unspecified behavior
The following are unspecified:
.. Whether two string literals result in distinct arrays (6.4.5).
Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Keeping <john@metanate.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: clang-built-linux@googlegroups.com
Link: https://github.com/ClangBuiltLinux/linux/issues/900
Link: http://lore.kernel.org/lkml/20200223193456.25291-1-nick.desaulniers@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/builtin-diff.c')
| -rw-r--r-- | tools/perf/builtin-diff.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c index f8b6ae557d8b..c03c36fde7e2 100644 --- a/tools/perf/builtin-diff.c +++ b/tools/perf/builtin-diff.c @@ -1312,7 +1312,8 @@ static int cycles_printf(struct hist_entry *he, struct hist_entry *pair, end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, he->ms.sym); - if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { + if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && + (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { scnprintf(buf, sizeof(buf), "[%s -> %s] %4ld", start_line, end_line, block_he->diff.cycles); } else { |