diff --git a/src/basic/util.h b/src/basic/util.h index 9699d22..27b5a09 100644 --- a/src/basic/util.h +++ b/src/basic/util.h @@ -134,11 +134,20 @@ static inline void *mempset(void *s, int c, size_t n) { } static inline void _reset_errno_(int *saved_errno) { + if (*saved_errno < 0) /* Invalidated by UNPROTECT_ERRNO? */ + return; + errno = *saved_errno; } #define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno +#define UNPROTECT_ERRNO \ + do { \ + errno = _saved_errno_; \ + _saved_errno_ = -1; \ + } while (false) + static inline int negative_errno(void) { /* This helper should be used to shut up gcc if you know 'errno' is * negative. Instead of "return -errno;", use "return negative_errno();" diff --git a/src/test/test-fs-util.c b/src/test/test-fs-util.c index fc650b5..7b7990b 100644 --- a/src/test/test-fs-util.c +++ b/src/test/test-fs-util.c @@ -322,11 +322,11 @@ static void test_unlink_noerrno(void) { { PROTECT_ERRNO; - errno = -42; + errno = 42; assert_se(unlink_noerrno(name) >= 0); - assert_se(errno == -42); + assert_se(errno == 42); assert_se(unlink_noerrno(name) < 0); - assert_se(errno == -42); + assert_se(errno == 42); } } diff --git a/src/test/test-util.c b/src/test/test-util.c index 4d3e5c5..df60d89 100644 --- a/src/test/test-util.c +++ b/src/test/test-util.c @@ -164,6 +164,30 @@ static void test_protect_errno(void) { assert_se(errno == 12); } +static void test_unprotect_errno_inner_function(void) { + PROTECT_ERRNO; + + errno = 2222; +} + +static void test_unprotect_errno(void) { + log_info("/* %s */", __func__); + + errno = 4711; + + PROTECT_ERRNO; + + errno = 815; + + UNPROTECT_ERRNO; + + assert_se(errno == 4711); + + test_unprotect_errno_inner_function(); + + assert_se(errno == 4711); +} + static void test_in_set(void) { assert_se(IN_SET(1, 1)); assert_se(IN_SET(1, 1, 2, 3, 4)); @@ -307,6 +331,7 @@ int main(int argc, char *argv[]) { test_div_round_up(); test_u64log2(); test_protect_errno(); + test_unprotect_errno(); test_in_set(); test_log2i(); test_raw_clone();