configure: Suppress Clang warning on carg()

[empserver] / configure.ac

diff --git a/configure.ac b/configure.ac
index e49eb3b3080997d7783a06ddf756d001d00b03f8..a80a95af70c15c3068715f49264838080dfa35f2 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -50,7 +50,6 @@ AC_PROG_AWK
 AC_PROG_INSTALL
 AC_PROG_RANLIB
 AC_PROG_CC
-AC_SUBST(GCC)
 AM_PROG_CC_C_O
 # Private automake macro, tsk, tsk, tsk...
 _AM_DEPENDENCIES(CC)
@@ -81,6 +80,40 @@ LIBS_server="$LIBS"
 
 ### Checks for typedefs, structures, and compiler characteristics
 
+# Enable useful warnings
+# Some of them are commented out because the code needs cleanup first
+# Clang needs to be tested with -Werror=unknown-warning-option
+AX_CHECK_COMPILE_FLAG([-Werror=unknown-warning-option],
+[cflags_test="-Werror=unknown-warning-option"],
+[cflags_test=""])
+MY_APPEND_COMPILE_FLAGS([-Wall -Wextra dnl
+dnl -Wcast-align dnl
+dnl -Wconversion dnl
+-Wdeclaration-after-statement dnl
+dnl -Wformat-nonliteral dnl
+-Wformat-security dnl
+-Winit-self dnl
+-Wlogical-op dnl
+-Wmissing-prototypes dnl
+-Wnested-externs dnl
+-Wold-style-definition dnl
+-Wpacked dnl
+-Wpointer-arith dnl
+-Wredundant-decls dnl
+dnl -Wshadow dnl
+-Wstrict-prototypes dnl
+dnl too prone to false positives: -Wsuggest-attribute=format dnl
+dnl -Wswitch-default dnl
+-Wundef dnl
+-Wno-unused-parameter dnl
+], [], [$cflags_test])
+
+# Our carg() conflicts with libm's TODO clean that up
+MY_APPEND_COMPILE_FLAGS([-fno-builtin-carg -Wno-incompatible-library-redeclaration])
+
+# No multiple definitions of uninitialized global variables
+MY_APPEND_COMPILE_FLAGS([-fno-common])
+
 
 ### Checks for library functions