Fix LM_TRY_ENABLE_CFLAG to use correct environment

LM_TRY_ENABLE_CFLAG takes which environment variable should be updated
but only CFLAGS was updated. Though CFLAGS is the normally the intended
variable, others may be used. For instance CXXFLAGS.

7 files changed, 23 insertions, 29 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index 5d555a5123..918e30a886 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1861,17 +1861,16 @@ dnl Usage example LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
 dnl
 dnl
 AC_DEFUN([LM_TRY_ENABLE_CFLAG], [
-    AC_MSG_CHECKING([if we can add $1 to CFLAGS])
+    AC_MSG_CHECKING([if we can add $1 to $2 (via CFLAGS)])
     saved_CFLAGS=$CFLAGS;
-    CFLAGS="$1 $CFLAGS";
+    CFLAGS="$1 $$2";
     AC_TRY_COMPILE([],[return 0;],can_enable_flag=true,can_enable_flag=false)
     CFLAGS=$saved_CFLAGS;
     if test "X$can_enable_flag" = "Xtrue"; then
         AC_MSG_RESULT([yes])
-        AS_VAR_SET($2, "$1 $CFLAGS")
+        AS_VAR_SET($2, "$1 $$2")
     else
         AC_MSG_RESULT([no])
-        AS_VAR_SET($2, "$CFLAGS")
     fi
 ])
 
diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index 5d555a5123..918e30a886 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -1861,17 +1861,16 @@ dnl Usage example LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
 dnl
 dnl
 AC_DEFUN([LM_TRY_ENABLE_CFLAG], [
-    AC_MSG_CHECKING([if we can add $1 to CFLAGS])
+    AC_MSG_CHECKING([if we can add $1 to $2 (via CFLAGS)])
     saved_CFLAGS=$CFLAGS;
-    CFLAGS="$1 $CFLAGS";
+    CFLAGS="$1 $$2";
     AC_TRY_COMPILE([],[return 0;],can_enable_flag=true,can_enable_flag=false)
     CFLAGS=$saved_CFLAGS;
     if test "X$can_enable_flag" = "Xtrue"; then
         AC_MSG_RESULT([yes])
-        AS_VAR_SET($2, "$1 $CFLAGS")
+        AS_VAR_SET($2, "$1 $$2")
     else
         AC_MSG_RESULT([no])
-        AS_VAR_SET($2, "$CFLAGS")
     fi
 ])
 
diff --git a/lib/erl_interface/aclocal.m4 b/lib/erl_interface/aclocal.m4
index 5d555a5123..918e30a886 100644
--- a/lib/erl_interface/aclocal.m4
+++ b/lib/erl_interface/aclocal.m4
@@ -1861,17 +1861,16 @@ dnl Usage example LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
 dnl
 dnl
 AC_DEFUN([LM_TRY_ENABLE_CFLAG], [
-    AC_MSG_CHECKING([if we can add $1 to CFLAGS])
+    AC_MSG_CHECKING([if we can add $1 to $2 (via CFLAGS)])
     saved_CFLAGS=$CFLAGS;
-    CFLAGS="$1 $CFLAGS";
+    CFLAGS="$1 $$2";
     AC_TRY_COMPILE([],[return 0;],can_enable_flag=true,can_enable_flag=false)
     CFLAGS=$saved_CFLAGS;
     if test "X$can_enable_flag" = "Xtrue"; then
         AC_MSG_RESULT([yes])
-        AS_VAR_SET($2, "$1 $CFLAGS")
+        AS_VAR_SET($2, "$1 $$2")
     else
         AC_MSG_RESULT([no])
-        AS_VAR_SET($2, "$CFLAGS")
     fi
 ])
 
diff --git a/lib/megaco/aclocal.m4 b/lib/megaco/aclocal.m4
index 5d555a5123..918e30a886 100644
--- a/lib/megaco/aclocal.m4
+++ b/lib/megaco/aclocal.m4
@@ -1861,17 +1861,16 @@ dnl Usage example LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
 dnl
 dnl
 AC_DEFUN([LM_TRY_ENABLE_CFLAG], [
-    AC_MSG_CHECKING([if we can add $1 to CFLAGS])
+    AC_MSG_CHECKING([if we can add $1 to $2 (via CFLAGS)])
     saved_CFLAGS=$CFLAGS;
-    CFLAGS="$1 $CFLAGS";
+    CFLAGS="$1 $$2";
     AC_TRY_COMPILE([],[return 0;],can_enable_flag=true,can_enable_flag=false)
     CFLAGS=$saved_CFLAGS;
     if test "X$can_enable_flag" = "Xtrue"; then
         AC_MSG_RESULT([yes])
-        AS_VAR_SET($2, "$1 $CFLAGS")
+        AS_VAR_SET($2, "$1 $$2")
     else
         AC_MSG_RESULT([no])
-        AS_VAR_SET($2, "$CFLAGS")
     fi
 ])
 
diff --git a/lib/megaco/configure.in b/lib/megaco/configure.in
index 9c3858f562..643267a154 100644
--- a/lib/megaco/configure.in
+++ b/lib/megaco/configure.in
@@ -162,6 +162,11 @@ else
 fi
 AC_SUBST(OTP_EXTRA_FLAGS)
 
+if test "x$GCC" = xyes; then
+  # Treat certain GCC warnings as errors
+  LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
+fi
+
 dnl
 dnl If ${ERL_TOP}/make/otp_ded.mk.in exists and contains DED_MK_VSN > 0,
 dnl every thing releted to compiling Dynamic Erlang Drivers can be found
@@ -273,11 +278,6 @@ if test "$PERL" = no_perl; then
   AC_MSG_ERROR([Perl is required to build the flex scanner!])
 fi
 
-if test "x$GCC" = xyes; then
-  # Treat certain GCC warnings as errors
-  LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
-fi
-
 AC_OUTPUT(examples/meas/Makefile:examples/meas/Makefile.in)
 AC_OUTPUT(src/flex/$host/Makefile:src/flex/Makefile.in)
 
diff --git a/lib/odbc/aclocal.m4 b/lib/odbc/aclocal.m4
index 5d555a5123..918e30a886 100644
--- a/lib/odbc/aclocal.m4
+++ b/lib/odbc/aclocal.m4
@@ -1861,17 +1861,16 @@ dnl Usage example LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
 dnl
 dnl
 AC_DEFUN([LM_TRY_ENABLE_CFLAG], [
-    AC_MSG_CHECKING([if we can add $1 to CFLAGS])
+    AC_MSG_CHECKING([if we can add $1 to $2 (via CFLAGS)])
     saved_CFLAGS=$CFLAGS;
-    CFLAGS="$1 $CFLAGS";
+    CFLAGS="$1 $$2";
     AC_TRY_COMPILE([],[return 0;],can_enable_flag=true,can_enable_flag=false)
     CFLAGS=$saved_CFLAGS;
     if test "X$can_enable_flag" = "Xtrue"; then
         AC_MSG_RESULT([yes])
-        AS_VAR_SET($2, "$1 $CFLAGS")
+        AS_VAR_SET($2, "$1 $$2")
     else
         AC_MSG_RESULT([no])
-        AS_VAR_SET($2, "$CFLAGS")
     fi
 ])
 
diff --git a/lib/wx/aclocal.m4 b/lib/wx/aclocal.m4
index 5d555a5123..918e30a886 100644
--- a/lib/wx/aclocal.m4
+++ b/lib/wx/aclocal.m4
@@ -1861,17 +1861,16 @@ dnl Usage example LM_TRY_ENABLE_CFLAG([-Werror=return-type], [CFLAGS])
 dnl
 dnl
 AC_DEFUN([LM_TRY_ENABLE_CFLAG], [
-    AC_MSG_CHECKING([if we can add $1 to CFLAGS])
+    AC_MSG_CHECKING([if we can add $1 to $2 (via CFLAGS)])
     saved_CFLAGS=$CFLAGS;
-    CFLAGS="$1 $CFLAGS";
+    CFLAGS="$1 $$2";
     AC_TRY_COMPILE([],[return 0;],can_enable_flag=true,can_enable_flag=false)
     CFLAGS=$saved_CFLAGS;
     if test "X$can_enable_flag" = "Xtrue"; then
         AC_MSG_RESULT([yes])
-        AS_VAR_SET($2, "$1 $CFLAGS")
+        AS_VAR_SET($2, "$1 $$2")
     else
         AC_MSG_RESULT([no])
-        AS_VAR_SET($2, "$CFLAGS")
     fi
 ])