Ramsay JonesThe POSIX standard specifies a return type of int for all six exec functions. In addition, all exec functions return -1 on error, and simply do not return on success. However, the current emulation of the exec functions on mingw are declared with a void return type.
This would cause a problem should any code attempt to call the exec function in a non-void context. In particular, if an exec function were used in a conditional it would fail to compile.
In order to improve the fidelity of the emulation, we change the return type of the mingw_execv[p] functions to int and return -1 on error.
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> ---
Hi Jeff,
Since commit b0984f82 ("run-command: treat inaccessible directories as ENOENT", 30-03-2012), the mingw build fails as follows:
CC run-command.o
run-command.c: In function 'sane_execvp':
run-command.c:124: error: invalid use of void expression
make: *** [run-command.o] Error 1My first reaction was to simply remove the conditional since, if execvp() returns at all, the result will always be -1 and so the condition will always be false. ie. the conditional is pointless.
However, I found the incorrect return type of the mingw_execv[p]() to be a gratuitous incompatibility, so ... :-P
Could you (or Junio?) add this patch prior to your patch on this branch ? Thanks in advance!
I will let you decide if you want to remove the conditional as well ...
ATB, Ramsay Jones
compat/mingw.c | 6 ++++-- compat/mingw.h | 4 ++-- 2 files changed, 6 insertions(+), 4 deletions(-)
Show changes to 2 files +6 −4
compat/mingw.c, compat/mingw.h
diff --git a/compat/mingw.c b/compat/mingw.c index a0ac487..afc892d 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1003,7 +1003,7 @@ static void mingw_execve(const char *cmd, char *const *argv, char *const *env) } } -void mingw_execvp(const char *cmd, char *const *argv) +int mingw_execvp(const char *cmd, char *const *argv) { char **path = get_path_split(); char *prog = path_lookup(cmd, path, 0); @@ -1015,11 +1015,13 @@ void mingw_execvp(const char *cmd, char *const *argv) errno = ENOENT; free_path_split(path); + return -1; } -void mingw_execv(const char *cmd, char *const *argv) +int mingw_execv(const char *cmd, char *const *argv) { mingw_execve(cmd, argv, environ); + return -1; } int mingw_kill(pid_t pid, int sig) diff --git a/compat/mingw.h b/compat/mingw.h index 0ff1e04..ef5b150 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -274,9 +274,9 @@ int mingw_utime(const char *file_name, const struct utimbuf *times); pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env, const char *dir, int fhin, int fhout, int fherr); -void mingw_execvp(const char *cmd, char *const *argv); +int mingw_execvp(const char *cmd, char *const *argv); #define execvp mingw_execvp -void mingw_execv(const char *cmd, char *const *argv); +int mingw_execv(const char *cmd, char *const *argv); #define execv mingw_execv static inline unsigned int git_ntohl(unsigned int x)
-- 1.7.9
