Merge pull request #5783 from keszybz/compiler-warning-fixes

shared/extract-word: replace enum with int to avoid undefined behaviour

2 files changed, 7 insertions, 2 deletions

diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c
index f8cac3e911..804f14c44c 100644
--- a/src/basic/extract-word.c
+++ b/src/basic/extract-word.c
@@ -241,7 +241,12 @@ int extract_first_word_and_warn(
         return log_syntax(unit, LOG_ERR, filename, line, r, "Unable to decode word \"%s\", ignoring: %m", rvalue);
 }
 
-int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) {
+/* We pass ExtractFlags as unsigned int (to avoid undefined behaviour when passing
+ * an object that undergoes default argument promotion as an argument to va_start).
+ * Let's make sure that ExtractFlags fits into an unsigned int. */
+assert_cc(sizeof(enum ExtractFlags) <= sizeof(unsigned));
+
+int extract_many_words(const char **p, const char *separators, unsigned flags, ...) {
         va_list ap;
         char **l;
         int n = 0, i, c, r;
diff --git a/src/basic/extract-word.h b/src/basic/extract-word.h
index 21db5ef33f..04746c6d08 100644
--- a/src/basic/extract-word.h
+++ b/src/basic/extract-word.h
@@ -32,4 +32,4 @@ typedef enum ExtractFlags {
 
 int extract_first_word(const char **p, char **ret, const char *separators, ExtractFlags flags);
 int extract_first_word_and_warn(const char **p, char **ret, const char *separators, ExtractFlags flags, const char *unit, const char *filename, unsigned line, const char *rvalue);
-int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) _sentinel_;
+int extract_many_words(const char **p, const char *separators, unsigned flags, ...) _sentinel_;