Re: [PATCH 0/5] consistent setup code for external commands

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 6, 2016, 15:17 UTC
Message-ID: <xmqq60sivlrt.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20160701223912.GB32545@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 22 quoted lines

> On Fri, Jul 01, 2016 at 03:19:37PM -0700, Junio C Hamano wrote:
>
>> > Here they are:
>> >
>> >   [1/5]: add an extra level of indirection to main()
>> >   [2/5]: common-main: call git_extract_argv0_path()
>> >   [3/5]: common-main: call sanitize_stdfds()
>> >   [4/5]: common-main: call restore_sigpipe_to_default()
>> >   [5/5]: common-main: call git_setup_gettext()
>> 
>> As this is also a fix to maint-2.8 track, I tweaked them to ensure
>> that they apply there, and queued the result as jk/common-main.  I
>> double checked the result by comparing the result of applying these
>> five patches directly on top of master, and the result of merging
>> that jk/common-main (based on maint-2.8) into master, and they seem
>> to match.
>
> Thanks, this obviously is a regression in v2.8, but I didn't even think
> about that and just built it on top of master.
>
> I think the cleanup that Dscho suggested elsewhere in the thread is a
> good idea on top, but that can also just wait and come separately.

OK.

I think that amounts to the following single patch, which I cherry picked from the topic in Dscho's repository he mentioned earlier.

With this applied on top of jk/common-main-2.8, when I merge it to his b764cdf, the result matches his common-main topic, so we three are on the same page, I'd think, and the result can be fed to the 2.8.x maintenance track.

-- >8 --
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 1 Jul 2016 15:01:28 +0200
Subject: [PATCH] mingw: declare main()'s argv as const

In 84d32bf (sparse: Fix mingw_main() argument number/type errors, 2013-04-27), we addressed problems identified by the 'sparse' tool where argv was declared inconsistently. The way we addressed it was by casting from the non-const version to the const-version.

This patch is long overdue, fixing compat/mingw.h's declaration to make the "argv" parameter const. This also allows us to lose the "const" trickery introduced earlier to common-main.c:main().

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 common-main.c  | 8 +-------
 compat/mingw.h | 2 +-
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/common-main.c b/common-main.c
index 3be5ad1..44a29e8 100644
--- a/common-main.c
+++ b/common-main.c
@@ -22,15 +22,9 @@ static void restore_sigpipe_to_default(void)
 	signal(SIGPIPE, SIG_DFL);
 }
 
-int main(int argc, char **av)
+int main(int argc, const char **argv)
 {
 	/*
-	 * This const trickery is explained in
-	 * 84d32bf7678259c08406571cd6ce4b7a6724dcba
-	 */
-	const char **argv = (const char **)av;
-
-	/*
 	 * Always open file descriptors 0/1/2 to avoid clobbering files
 	 * in die().  It also avoids messing up when the pipes are dup'ed
 	 * onto stdin/stdout/stderr in the child processes we spawn.
diff --git a/compat/mingw.h b/compat/mingw.h
index 69bb43d..1ac9086 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -535,7 +535,7 @@ extern CRITICAL_SECTION pinfo_cs;
 void mingw_startup();
 #define main(c,v) dummy_decl_mingw_main(); \
 static int mingw_main(c,v); \
-int main(int argc, char **argv) \
+int main(int argc, const char **argv) \
 { \
 	mingw_startup(); \
 	return mingw_main(__argc, (void *)__argv); \

-- 
2.9.0-457-ge524329