Jonathan Nieder <jrnieder@xxxxxxxxx> writes:
> In October, Thomas Gummerer wrote:
>> On 10/12, Jonathan Nieder wrote:
>>> Jeff King wrote:
>>> ...
>>>> -Wformat is part of -Wall, which we already turn on by default (even for
>>>> non-developer builds).
> ...
> As discussed in [1], autoconf appears to not put -Wall in CFLAGS:
>
> $ make configure
> GEN configure
> $ ./configure
> [...]
> config.status: creating config.mak.autogen
> config.status: executing config.mak.autogen commands
> $ grep CFLAGS config.mak.autogen
> CFLAGS = -g -O2
> PTHREAD_CFLAGS=-pthread
>
> So this trap for the unwary is still around.
>
> Can we revive this patch? Does it just need a clearer commit message,
> or were there other objections?
I think it is a good idea to give fallback/redundancy for this
case. I do not have strong opinion between -Wall and -Wformat,
but I'd probably vote for the former if pressed.
-- >8 --
From: Thomas Gummerer <t.gummerer@xxxxxxxxx>
Date: Fri, 12 Oct 2018 19:40:37 +0100
Subject: [PATCH] config.mak.dev: add -Wformat
801fa63a90 ("config.mak.dev: add -Wformat-security", 2018-09-08)
added the "-Wformat-security" to the flags set in config.mak.dev.
In the gcc man page this is documented as:
If -Wformat is specified, also warn about uses of format
functions that represent possible security problems. [...]
The commit did however not add the "-Wformat" flag, but instead
relied on the fact that "-Wall" is set in the Makefile by default
and that "-Wformat" is part of "-Wall".
Unfortunately, those who use config.mak.autogen generated with the
autoconf to configure toolchain do *not* get "-Wall" in their CFLAGS
and the added -Wformat-security had no effect. Worse yet, newer
versions of gcc (gcc 8.2.1 in this particular case) warn about the
lack of "-Wformat" and thus compilation fails only with this option
set.
We could fix it by adding "-Wformat", but in general we do want all
checks included in "-Wall", so let's add it to config.mak.dev to
cover more cases.
Signed-off-by: Thomas Gummerer <t.gummerer@xxxxxxxxx>
Helped-by: Jeff King <peff@xxxxxxxx>
Helped-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
[jc: s/-Wformat/-Wall/]
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
config.mak.dev | 1 +
1 file changed, 1 insertion(+)
diff --git a/config.mak.dev b/config.mak.dev
index bfbd3df4e8..74337f1f92 100644
--- a/config.mak.dev
+++ b/config.mak.dev
@@ -1,6 +1,7 @@
ifeq ($(filter no-error,$(DEVOPTS)),)
CFLAGS += -Werror
endif
+CFLAGS += -Wall
CFLAGS += -Wdeclaration-after-statement
CFLAGS += -Wformat-security
CFLAGS += -Wno-format-zero-length
--
2.20.1-2-gb21ebb671b
