From 81fe13eeed91d5c973db63d2f662ae766a8832c4 Mon Sep 17 00:00:00 2001 From: Corey Farrell Date: Sat, 14 Jul 2018 13:24:55 -0400 Subject: [PATCH] Deal with warnings under gcc 8. Recent versions of gcc have introduced compiler warnings for string operations that could be truncated. This caused problems with -Werror. src/error.c used strncpy to write "..." to a string, but skipped writing the NUL terminator. Switch this to use memcpy. src/load.c produced warnings from snprintf writing error strings that could be truncated. Added code to autotools build to detect `-Wno-format-truncation', add it to AM_CFLAGS if supported. --- configure.ac | 9 ++++++++- src/error.c | 2 +- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/configure.ac b/configure.ac index 4ab9d3d..ca12b59 100644 --- a/configure.ac +++ b/configure.ac @@ -108,7 +108,14 @@ AC_DEFINE_UNQUOTED([INITIAL_HASHTABLE_ORDER], [$initial_hashtable_order], [Number of buckets new object hashtables contain is 2 raised to this power. E.g. 3 -> 2^3 = 8.]) if test x$GCC = xyes; then - AM_CFLAGS="-Wall -Wextra -Wdeclaration-after-statement" + AC_MSG_CHECKING(for -Wno-format-truncation) + wnoformat_truncation="-Wno-format-truncation" + AS_IF([${CC} -Wno-format-truncation -Werror -S -o /dev/null -xc /dev/null > /dev/null 2>&1], + [AC_MSG_RESULT(yes)], + [AC_MSG_RESULT(no) + wnoformat_truncation=""]) + + AM_CFLAGS="-Wall -Wextra -Wdeclaration-after-statement ${wnoformat_truncation}" fi AC_SUBST([AM_CFLAGS]) diff --git a/src/error.c b/src/error.c index cbd50d7..f5da6b9 100644 --- a/src/error.c +++ b/src/error.c @@ -28,7 +28,7 @@ void jsonp_error_set_source(json_error_t *error, const char *source) strncpy(error->source, source, length + 1); else { size_t extra = length - JSON_ERROR_SOURCE_LENGTH + 4; - strncpy(error->source, "...", 3); + memcpy(error->source, "...", 3); strncpy(error->source + 3, source + extra, length - extra + 1); } }