From 09ecbb76745b4189f07e339131c1df4f46a03531 Mon Sep 17 00:00:00 2001
From: Neels Hofmeyr <neels@hofmeyr.de>
Date: Mon, 5 Mar 2018 20:40:05 +0100
Subject: configure: add --enable-werror

Provide a sane means of adding the -Werror compiler flag.

Currently, some of our jenkins.sh add -Werror by passing 'CFLAGS="-Werror"',
but that actually *overwrites* all the other CFLAGS we might want to have set.

Maintain these exceptions from -Werror:
a) deprecation (allow upstream to mark deprecation without breaking builds);
b) "#warning" pragmas (allow to remind ourselves of errors without breaking
   builds)

As a last configure step before generating the output files, print the complete
CFLAGS and CPPFLAGS by means of AC_MSG_RESULT.

Change-Id: Ic5c8e68b64cd890b3309b4b26c7f22bde1edba83
---
 configure.ac | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

(limited to 'configure.ac')

diff --git a/configure.ac b/configure.ac
index 60c177f8..7f2aabd1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -272,6 +272,24 @@ then
 	CPPFLAGS="$CPPFLAGS -fsanitize=address -fsanitize=undefined"
 fi
 
+AC_ARG_ENABLE(werror,
+	[AS_HELP_STRING(
+		[--enable-werror],
+		[Turn all compiler warnings into errors, with exceptions:
+		 a) deprecation (allow upstream to mark deprecation without breaking builds);
+		 b) "#warning" pragmas (allow to remind ourselves of errors without breaking builds)
+		]
+	)],
+	[werror=$enableval], [werror="no"])
+if test x"$werror" = x"yes"
+then
+	WERROR_FLAGS="-Werror"
+	WERROR_FLAGS+=" -Wno-error=deprecated -Wno-error=deprecated-declarations"
+	WERROR_FLAGS+=" -Wno-error=cpp" # "#warning"
+	CFLAGS="$CFLAGS $WERROR_FLAGS"
+	CPPFLAGS="$CPPFLAGS $WERROR_FLAGS"
+fi
+
 CFLAGS="$CFLAGS -DBUILDING_LIBOSMOCORE -Wall"
 CPPFLAGS="$CPPFLAGS -DBUILDING_LIBOSMOCORE -Wall"
 
@@ -318,6 +336,9 @@ dnl Check if the compiler supports runtime SIMD detection
 CHECK_BUILTIN_SUPPORT([__builtin_cpu_supports],
   [Runtime SIMD detection will be disabled])
 
+AC_MSG_RESULT([CFLAGS="$CFLAGS"])
+AC_MSG_RESULT([CPPFLAGS="$CPPFLAGS"])
+
 AC_OUTPUT(
 	libosmocore.pc
 	libosmocodec.pc
-- 
cgit v1.2.3