From: Simon Marchi Date: Tue, 18 Feb 2020 18:14:22 +0000 (-0500) Subject: configure: simplify warning flags detection X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=28ba44ad9ca14153e96c94a9100423ea224c1af3;hp=28ba44ad9ca14153e96c94a9100423ea224c1af3;p=babeltrace.git configure: simplify warning flags detection We currently use the AX_COMPILER_FLAGS macro to detect the warning flags that the current compiler supports. It works, but is quite invasive. It unconditionally enables a bunch of warnings we don't want, which forces us to disable them with many -Wno-foo switches. Instead of using AX_COMPILER_FLAGS, we can use the slightly lower lever macro AX_APPEND_COMPILE_FLAGS to achieve our goal of detecting which warning flags are supported. This is what we ended up using in lttng-tools (a completely unrelated project, but that has a suspiciously high ratio of contributors in common with Babeltrace). I looked in our git history to see which warning flags were mentioned in commit messages. I have added the flags that did find actual problems and are not enabled by default to the AX_APPEND_COMPILE_FLAGS invocation. I have also added the flags that AX_COMPILER_FLAGS did provide, which we didn't need to disable. The --{enable,disable}-Werror flag is added using an explicit AC_ARG_ENABLE. In lttng-tools, it was decided to _not_ have -Werror by default, so I suggest we do the same in Babeltrace, for consistency (although it saddens me very much). Developers who want to build with -Werror will need to pass --enable-Werror. Note that with this patch, we lose the following configure switch, that is provided by AX_COMPILER_FLAGS: --enable-compile-warnings=[no/yes/error] Change-Id: If968f7385a7f5c48d27f402c76bc26241a8f505a Signed-off-by: Simon Marchi Reviewed-on: https://review.lttng.org/c/babeltrace/+/3209 Tested-by: jenkins Reviewed-by: Michael Jeanson ---