X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=configure.ac;h=a997ba3b9e6c62d2e6148ecb09ae1b524cabaa27;hp=852c61f0e246e025849d3a63256b34977cc01b10;hb=b670b3048650a2568e1fd782843252bb237851cb;hpb=bfb025cd1038e01972c11fdf5fcad8b044b03f76

diff --git a/configure.ac b/configure.ac
index 852c61f0e..a997ba3b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -26,6 +26,31 @@ AC_PROG_CXX
 RW_PROG_CXX_WORKS
 AM_CONDITIONAL([CXX_WORKS], [test "x$rw_cv_prog_cxx_works" = "xyes"])
 
+# Detect warning flags supported by the compiler, append them to WARN_CFLAGS.
+#
+# Pass -Werror as an extra flag during the test: this is needed to make the
+# -Wunknown-warning-option diagnostic fatal with clang.
+AX_APPEND_COMPILE_FLAGS([ dnl
+		-Wall dnl
+		dnl We currently get this warning when building with Clang:
+		dnl
+		dnl /usr/include/setjmp.h:54:12: error: declaration of built-in function '__sigsetjmp' requires the declaration of the 'jmp_buf' type, commonly provided in the header <setjmp.h>. [-Werror,-Wincomplete-setjmp-declaration]
+		dnl extern int __sigsetjmp (struct __jmp_buf_tag __env[1], int __savemask) __THROWNL;
+		dnl            ^
+		-Wno-incomplete-setjmp-declaration dnl
+		-Wdiscarded-qualifiers dnl
+	],
+	[WARN_CFLAGS],
+	[-Werror])
+
+# When given, add -Werror to WARN_CFLAGS.
+AC_ARG_ENABLE([Werror],
+	[AS_HELP_STRING([--enable-Werror], [Treat compiler warnings as errors.])]
+)
+AS_IF([test "x$enable_Werror" = "xyes"],
+	[WARN_CFLAGS="${WARN_CFLAGS} -Werror"]
+)
+
 # Checks for programs.
 AC_PROG_GREP
 AC_PROG_MAKE_SET
@@ -1038,9 +1063,13 @@ AM_CONDITIONAL([BUILD_LIB_SESSIOND_COMM], [test x$build_lib_sessiond_comm = xyes
 AM_CONDITIONAL([BUILD_LIB_TESTPOINT], [test x$build_lib_testpoint = xyes])
 AM_CONDITIONAL([BUILD_LIB_UST_CONSUMER], [test x$build_lib_ust_consumer = xyes])
 
-AM_CFLAGS="-Wall -fno-strict-aliasing $PTHREAD_CFLAGS"
+AM_CFLAGS="${WARN_CFLAGS} -fno-strict-aliasing $PTHREAD_CFLAGS"
 AC_SUBST(AM_CFLAGS)
 
+# This is set even though it is empty, so Makefiles can do "AM_LDFLAGS += ...".
+AM_LDFLAGS=""
+AC_SUBST(AM_LDFLAGS)
+
 # The order in which the include folders are searched is important.
 # The top_builddir should always be searched first in the event that a build
 # time generated file is included. An example of this is the "version.i" file.