Bootstrap the build system for C++ as well.

That is, check CXX support for strict compiler flags.

Also, use all configured strict flags when checking for other strict flags.
This way, we detect problems when using flags that are not supported in C++
mode.

diff --git a/configure.ac b/configure.ac
index e395d5f1b0408e600e8f483277a6fff0c81bdf23..10c18c9add8aa80b8e2ff60fb132958722242d50 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -44,6 +44,7 @@ AC_LANG(C)
 AC_SYS_LARGEFILE
 
 AC_PROG_CC
+AC_PROG_CXX
 AC_PROG_CPP
 AC_PROG_INSTALL
 AC_PROG_LN_S
@@ -72,14 +73,25 @@ m4_ifdef([LT_INIT],
 )
 
 test_cc_flags() {
-       AC_LANG_CONFTEST([AC_LANG_PROGRAM([[ ]], [[ ]])])
-       $CC -c conftest.c $CFLAGS $@ > /dev/null 2> /dev/null
+       AC_LANG_CONFTEST([int main(void){}])
+       $CC -c conftest.c $CFLAGS $STRICT_CFLAGS $@ > /dev/null 2> /dev/null
        ret=$?
        rm -f conftest.o
        return $ret
 }
 
+test_cxx_flags() {
+       AC_LANG_PUSH(C++)
+       AC_LANG_CONFTEST([int main(void){}])
+       $CXX -c conftest.c $CXXFLAGS $STRICT_CXXFLAGS $@ > /dev/null 2> /dev/null
+       ret=$?
+       rm -f conftest.o
+       AC_LANG_POP(C++)
+       return $ret
+}
+
 STRICT_CFLAGS=""
+STRICT_CXXFLAGS=""
 
 m4_divert_once([HELP_ENABLE], [
 Build options:])
@@ -130,23 +142,37 @@ AC_ARG_ENABLE([hardening],
                [enable_hardening="yes"])
 
 if test "x$enable_hardening" = "xyes"; then
-       hardening=0
+       hardening_cc=0
+       hardening_cxx=0
        hardening_tests=0
        for flag in -Wformat -Wformat-security; do
                hardening_tests=$(($hardening_tests + 1))
-               AC_MSG_CHECKING([whether $CC accepts $flag])
 
+               AC_MSG_CHECKING([whether $CC accepts $flag])
                if test_cc_flags $flag; then
                        STRICT_CFLAGS="$STRICT_CFLAGS $flag"
-                       hardening=$(($hardening + 1))
+                       hardening_cc=$(($hardening_cc + 1))
+                       AC_MSG_RESULT([yes])
+               else
+                       AC_MSG_RESULT([no])
+               fi
+
+               AC_MSG_CHECKING([whether $CXX accepts $flag])
+               if test_cxx_flags $flag; then
+                       STRICT_CXXFLAGS="$STRICT_CXXFLAGS $flag"
+                       hardening_cxx=$(($hardening_cxx + 1))
                        AC_MSG_RESULT([yes])
                else
                        AC_MSG_RESULT([no])
                fi
        done
-       if test $hardening -ne $hardening_tests; then
+       if test $hardening_cc -ne $hardening_tests; then
                AC_MSG_WARN(
-                               [Some hardening options are not supported by your compiler!])
+                               [Some hardening options are not supported by your C compiler!])
+       fi
+       if test $hardening_cxx -ne $hardening_tests; then
+               AC_MSG_WARN(
+                               [Some hardening options are not supported by your C++ compiler!])
        fi
 fi
 
@@ -159,13 +185,20 @@ AC_ARG_ENABLE([strict-checks],
 
 for flag in -Wall -Werror; do
        AC_MSG_CHECKING([whether $CC accepts $flag])
-
        if test_cc_flags $flag; then
                STRICT_CFLAGS="$STRICT_CFLAGS $flag"
                AC_MSG_RESULT([yes])
        else
                AC_MSG_RESULT([no])
        fi
+
+       AC_MSG_CHECKING([whether $CXX accepts $flag])
+       if test_cxx_flags $flag; then
+               STRICT_CXXFLAGS="$STRICT_CXXFLAGS $flag"
+               AC_MSG_RESULT([yes])
+       else
+               AC_MSG_RESULT([no])
+       fi
 done
 
 if test "x$enable_strict_checks" = "xyes"; then
@@ -182,16 +215,28 @@ if test "x$enable_strict_checks" = "xyes"; then
                        -Wshadow \
                        -Wstrict-prototypes; do
                AC_MSG_CHECKING([whether $CC accepts $flag])
-
                if test_cc_flags $flag; then
                        STRICT_CFLAGS="$STRICT_CFLAGS $flag"
                        AC_MSG_RESULT([yes])
                else
                        AC_MSG_RESULT([no])
                fi
+
+               dnl -Wshadow produces unnecessary warnings/errors in case a
+               dnl C function name "shadows" a struct constructor.
+               if test "x$flag" != "x-Wshadow"; then
+                       AC_MSG_CHECKING([whether $CXX accepts $flag])
+                       if test_cxx_flags $flag; then
+                               STRICT_CXXFLAGS="$STRICT_CXXFLAGS $flag"
+                               AC_MSG_RESULT([yes])
+                       else
+                               AC_MSG_RESULT([no])
+                       fi
+               fi
        done
 fi
 AC_SUBST([STRICT_CFLAGS])
+AC_SUBST([STRICT_CXXFLAGS])
 
 AC_ARG_ENABLE([gcov],
                AS_HELP_STRING([--enable-gcov],

diff --git a/src/Makefile.am b/src/Makefile.am
index 64b6ec46c41a4639879357c846e3089f21d6f269..1583217d9d79c8ca0c61827be20daf6449922da6 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -2,6 +2,7 @@ SUBDIRS = liboconfig
 
 # coverage related flags are only set when gcov is enabled
 AM_CFLAGS = @STRICT_CFLAGS@ @COVERAGE_CFLAGS@ @PROFILING_CFLAGS@
+AM_CXXFLAGS = @STRICT_CXXFLAGS@ @COVERAGE_CFLAGS@ @PROFILING_CFLAGS@
 AM_LDFLAGS = @COVERAGE_LDFLAGS@ @PROFILING_LDFLAGS@
 AM_CPPFLAGS  = -I"${top_srcdir}/src/include"
 AM_CPPFLAGS += -DSYSCONFDIR='"${sysconfdir}"'