Merge branch 'jk/error-const-return'

Help compilers' flow analysis by making it more explicit that
error() always returns -1, to reduce false "variable used
uninitialized" warnings.  Looks somewhat ugly but not too much.

* jk/error-const-return:
  silence some -Wuninitialized false positives
  make error()'s constant return value more visible

1 files changed, 11 insertions, 0 deletions

diff --git a/git-compat-util.h b/git-compat-util.h
index 610e6b7..9661bc9 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -290,6 +290,17 @@ extern NORETURN void die_errno(const char *err, ...) __attribute__((format (prin
 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
+/*
+ * Let callers be aware of the constant return value; this can help
+ * gcc with -Wuninitialized analysis. We have to restrict this trick to
+ * gcc, though, because of the variadic macro and the magic ## comma pasting
+ * behavior. But since we're only trying to help gcc, anyway, it's OK; other
+ * compilers will fall back to using the function as usual.
+ */
+#ifdef __GNUC__
+#define error(fmt, ...) (error((fmt), ##__VA_ARGS__), -1)
+#endif
+
 extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
 extern void set_error_routine(void (*routine)(const char *err, va_list params));