From: Rob Browning <rlb@defaultvalue.org>
Date: Sat, 30 Oct 2021 19:07:55 +0000 (-0500)
Subject: configure: support optional cc arguments
X-Git-Url: https://arthur.barton.de/gitweb/?p=bup.git;a=commitdiff_plain;h=9118aca5f232cc9a4da573a367da31ea8bee2fd5;hp=7e054ad95acda596469c40159867f936c1a8f851

configure: support optional cc arguments

I noticed in some unrelated reports that older compilers were
rejecting -Wno-unsed-command-line-argument, so add
bup-add-cflag-if-supported to configure and use it for that argument.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>
Tested-by: Rob Browning <rlb@defaultvalue.org>
---

diff --git a/GNUmakefile b/GNUmakefile
index f3245f5..83d141d 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -40,9 +40,9 @@ LDFLAGS ?=
 TARGET_ARCH ?=
 
 bup_shared_cflags := -O2 -Wall -Werror -Wformat=2
-bup_shared_cflags := -Wno-unused-command-line-argument $(bup_shared_cflags)
 bup_shared_cflags := -Wno-unknown-pragmas -Wsign-compare $(bup_shared_cflags)
 bup_shared_cflags := -D_FILE_OFFSET_BITS=64 $(bup_shared_cflags)
+bup_shared_cflags := $(bup_config_cflags) $(bup_shared_cflags)
 
 bup_shared_ldflags :=
 
diff --git a/config/config.vars.in b/config/config.vars.in
index 627f995..4101ed3 100644
--- a/config/config.vars.in
+++ b/config/config.vars.in
@@ -2,6 +2,7 @@ CONFIGURE_FILES=@CONFIGURE_FILES@
 GENERATED_FILES=@GENERATED_FILES@
 
 CC = @CC@
+bup_config_cflags = @bup_config_cflags@
 bup_make=@bup_make@
 
 bup_python_config=@bup_python_config@
diff --git a/config/configure b/config/configure
index 85495ae..b27a419 100755
--- a/config/configure
+++ b/config/configure
@@ -35,6 +35,27 @@ bup_try_c_code()
     return $rc
 }
 
+bup_config_cflags=()
+
+bup-add-cflag-if-supported()
+{
+    local opt="$1"
+    if test -z "$opt"; then
+        AC_FAIL 'No option to check'
+    fi
+    TLOGN "checking for $AC_CC $opt support"
+    if bup_try_c_code \
+           "int main(int argc, char**argv) { return 0; }" \
+           "$opt";
+    then
+        bup_config_cflags+="$opt"
+        TLOG ' (found)'
+    else
+        TLOG ' (not found)'
+    fi
+}
+
+
 TARGET=bup
 
 argv=()
@@ -63,6 +84,8 @@ if ! AC_PROG_CC; then
     exit 1
 fi
 
+bup-add-cflag-if-supported -Wno-unused-command-line-argument
+
 for make_candidate in make gmake; do
     found_make="$(bup_find_prog "$make_candidate" "$MAKE")"
     if test "$found_make" \
@@ -331,6 +354,8 @@ AC_SUB bup_have_libacl "$bup_have_libacl"
 AC_CC="$orig_ac_cc"
 LIBS="$orig_libs"
 
+AC_SUB bup_config_cflags "$bup_config_cflags"
+
 AC_OUTPUT config.vars
 
 set -euo pipefail