-Wstring-compare in tools/perf/

[nickdesaulniers]

$ make CC=clang tools/perf
builtin-diff.c:1315:18: 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)) {
                        ^  ~~~~~~~~~~~~~~~
builtin-diff.c:1315:51: 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)) {
                                                         ^  ~~~~~~~~~~~~~~~
2 errors generated.
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)) {
                                                         ^  ~~~~~~~~~~~~~~~
2 errors generated.
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)
                            ^  ~~~~~~~~~~~~~~~
1 error generated.

[nickdesaulniers]

https://lore.kernel.org/lkml/20200223193456.25291-1-nick.desaulniers@gmail.com/T/#u

[nickdesaulniers]

https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/commit/?h=perf/urgent&id=cfd3bc752a3f5529506d279deb42e3bc8055695b

[nathanchance]

Merged into mainline: https://git.kernel.org/linus/cfd3bc752a3f5529506d279deb42e3bc8055695b