From 88f1a8fe4697b0921f39fcd9c7efc4a0486cf91b Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Thu, 12 Jul 2018 18:13:24 +0200 Subject: [PATCH 2/3] apps: Disable -Wstringop-truncation warning on false positives The GCC v8.1.0 warns: In function 'paste', inlined from 'get_hmac_file' at apps/kcapi-hasher.c:395:11: apps/kcapi-hasher.c:346:2: error: 'strncpy' destination unchanged after copying no bytes [-Werror=stringop-truncation] strncpy(dst, src, size); ^~~~~~~~~~~~~~~~~~~~~~~ These are false positives because at the end of paste() calls, the buffer is NULL terminated. Signed-off-by: Krzysztof Kozlowski Upstream-Status: Submitted --- apps/kcapi-hasher.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/apps/kcapi-hasher.c b/apps/kcapi-hasher.c index ae88211ff4dd..4052260bf871 100644 --- a/apps/kcapi-hasher.c +++ b/apps/kcapi-hasher.c @@ -61,6 +61,10 @@ #include "app-internal.h" +#define GCC_VERSION (__GNUC__ * 10000 \ + + __GNUC_MINOR__ * 100 \ + + __GNUC_PATCHLEVEL__) + struct hash_name { const char *kcapiname; const char *bsdname; @@ -341,6 +345,17 @@ out: return ret; } +/* + * GCC v8.1.0 introduced -Wstringop-truncation but it is not smart enough to + * find that cursor string will be NULL-terminated after all paste() calls and + * warns with: + * error: 'strncpy' destination unchanged after copying no bytes [-Werror=stringop-truncation] + * error: 'strncpy' output truncated before terminating nul copying 5 bytes from a string of the same length [-Werror=stringop-truncation] + */ +#pragma GCC diagnostic push +#if GCC_VERSION >= 80100 +#pragma GCC diagnostic ignored "-Wstringop-truncation" +#endif static char *paste(char *dst, const char *src, size_t size) { strncpy(dst, src, size); @@ -398,6 +413,7 @@ static char *get_hmac_file(const char *filename, const char *subdir) strncpy(cursor, "\0", 1); return checkfile; } +#pragma GCC diagnostic pop /* -Wstringop-truncation */ static int hash_files(const struct hash_params *params, char *filenames[], uint32_t files, -- 2.7.4