From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: [PATCH 1/2] vreportf: report to arbitrary filehandles Date: Tue, 11 Aug 2015 14:06:15 -0400 Message-ID: <20150811180614.GA18002@sigill.intra.peff.net> References: <20150811180524.GB15521@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: git@vger.kernel.org To: Junio C Hamano X-From: git-owner@vger.kernel.org Tue Aug 11 20:06:26 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZPDwP-0005pg-17 for gcvg-git-2@plane.gmane.org; Tue, 11 Aug 2015 20:06:25 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752594AbbHKSGU (ORCPT ); Tue, 11 Aug 2015 14:06:20 -0400 Received: from cloud.peff.net ([50.56.180.127]:43745 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751751AbbHKSGU (ORCPT ); Tue, 11 Aug 2015 14:06:20 -0400 Received: (qmail 26921 invoked by uid 102); 11 Aug 2015 18:06:19 -0000 Received: from Unknown (HELO peff.net) (10.0.1.1) by cloud.peff.net (qpsmtpd/0.84) with SMTP; Tue, 11 Aug 2015 13:06:19 -0500 Received: (qmail 17569 invoked by uid 107); 11 Aug 2015 18:06:30 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.84) with SMTP; Tue, 11 Aug 2015 14:06:30 -0400 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 11 Aug 2015 14:06:15 -0400 Content-Disposition: inline In-Reply-To: <20150811180524.GB15521@sigill.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: The vreportf function always goes to stderr, but run-command wants child errors to go to the parent's original stderr. To solve this, commit a5487dd duplicates the stderr fd and installs die and error handlers to direct the output appropriately (which later turned into the vwritef function). This has two downsides, though: - we make multiple calls to write(), which contradicts the "write at once" logic from d048a96 (print warning/error/fatal messages in one shot, 2007-11-09). - the custom handlers basically duplicate the normal handlers. They're only a few lines of code, but we should not have to repeat the magic "exit(128)", for example. We can solve the first by using fdopen() on the duplicated descriptor. We can't pass this to vreportf, but we could introduce a new vreportf_to to handle it. However, to fix the second problem, we instead introduce a new "set_error_handle" function, which lets the normal vreportf calls output to a handle besides stderr. Thus we can get rid of our custom handlers entirely, and just ask the regular handlers to output to our new descriptor. And as vwritef has no more callers, it can just go away. Signed-off-by: Jeff King --- git-compat-util.h | 2 +- run-command.c | 17 ++--------------- usage.c | 22 +++++++++------------- 3 files changed, 12 insertions(+), 29 deletions(-) diff --git a/git-compat-util.h b/git-compat-util.h index c6d391f..076461e 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -389,7 +389,6 @@ struct strbuf; /* General helper functions */ extern void vreportf(const char *prefix, const char *err, va_list params); -extern void vwritef(int fd, const char *prefix, const char *err, va_list params); extern NORETURN void usage(const char *err); extern NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2))); extern NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2))); @@ -425,6 +424,7 @@ static inline int const_error(void) 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)); extern void set_die_is_recursing_routine(int (*routine)(void)); +extern void set_error_handle(FILE *); extern int starts_with(const char *str, const char *prefix); diff --git a/run-command.c b/run-command.c index 4d73e90..0d01671 100644 --- a/run-command.c +++ b/run-command.c @@ -200,7 +200,6 @@ static int execv_shell_cmd(const char **argv) #endif #ifndef GIT_WINDOWS_NATIVE -static int child_err = 2; static int child_notifier = -1; static void notify_parent(void) @@ -212,17 +211,6 @@ static void notify_parent(void) */ xwrite(child_notifier, "", 1); } - -static NORETURN void die_child(const char *err, va_list params) -{ - vwritef(child_err, "fatal: ", err, params); - exit(128); -} - -static void error_child(const char *err, va_list params) -{ - vwritef(child_err, "error: ", err, params); -} #endif static inline void set_cloexec(int fd) @@ -362,11 +350,10 @@ fail_pipe: * in subsequent call paths use the parent's stderr. */ if (cmd->no_stderr || need_err) { - child_err = dup(2); + int child_err = dup(2); set_cloexec(child_err); + set_error_handle(fdopen(child_err, "w")); } - set_die_routine(die_child); - set_error_routine(error_child); close(notify_pipe[0]); set_cloexec(notify_pipe[1]); diff --git a/usage.c b/usage.c index ed14645..e4fa6d2 100644 --- a/usage.c +++ b/usage.c @@ -6,23 +6,14 @@ #include "git-compat-util.h" #include "cache.h" +static FILE *error_handle; + void vreportf(const char *prefix, const char *err, va_list params) { char msg[4096]; + FILE *fh = error_handle ? error_handle : stderr; vsnprintf(msg, sizeof(msg), err, params); - fprintf(stderr, "%s%s\n", prefix, msg); -} - -void vwritef(int fd, const char *prefix, const char *err, va_list params) -{ - char msg[4096]; - int len = vsnprintf(msg, sizeof(msg), err, params); - if (len > sizeof(msg)) - len = sizeof(msg); - - write_in_full(fd, prefix, strlen(prefix)); - write_in_full(fd, msg, len); - write_in_full(fd, "\n", 1); + fprintf(fh, "%s%s\n", prefix, msg); } static NORETURN void usage_builtin(const char *err, va_list params) @@ -76,6 +67,11 @@ void set_die_is_recursing_routine(int (*routine)(void)) die_is_recursing = routine; } +void set_error_handle(FILE *fh) +{ + error_handle = fh; +} + void NORETURN usagef(const char *err, ...) { va_list params; -- 2.5.0.417.g2db689c