[PATCH 3/4] configure: propagate --extra-cflags and --extra-ldflags to meson compile tests

[Paolo Bonzini]

Meson (intentionally) does not add QEMU_CFLAGS to cc.compiles/cc.links
tests, as they are supposed to be independent of the specific sets of
compilation flags used to build the programs.  However, the user can
still use CFLAGS or the toolchain file's LANG_args/LANG_link_args option
to specify -I or -L options that apply to cc.compiles/cc.links as well.

This is also the intended use of configure's --extra-cflags,
--extra-cxxflags and --extra-ldflags options.  For example, if
one has netmap's header in a nonstandard directory, up to commit
837b84b1c078bf3e909 it used to work fine to do:

.../configure --enable-netmap \
     --extra-cflags=-I/path/to/netmap/sys

but since the test was converted to meson, this does not work anymore.

Pass these options to meson via the toolchain file instead of via
config-host.mak, since the toolchain file's variables have the
same purpose as configure's --extra-*flags arguments.

Reported-by: Owen LaGarde
Reported-by: Thomas Huth <thuth@redhat.com>
Fixes: 47b30835e4 ("configure: consistently pass CFLAGS/CXXFLAGS/LDFLAGS to 
meson", 2020-10-06)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 configure | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/configure b/configure
index d268f59246..1ea26c67e5 100755
--- a/configure
+++ b/configure
@@ -174,14 +174,14 @@ update_cxxflags() {
 
 compile_object() {
   local_cflags="$1"
-  do_cc $CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags -c -o $TMPO $TMPC
+  do_cc $CFLAGS $EXTRA_CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags -c 
-o $TMPO $TMPC
 }
 
 compile_prog() {
   local_cflags="$1"
   local_ldflags="$2"
-  do_cc $CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags -o $TMPE $TMPC \
-      $LDFLAGS $CONFIGURE_LDFLAGS $QEMU_LDFLAGS $local_ldflags
+  do_cc $CFLAGS $EXTRA_CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags -o 
$TMPE $TMPC \
+      $LDFLAGS $EXTRA_LDFLAGS $CONFIGURE_LDFLAGS $QEMU_LDFLAGS $local_ldflags
 }
 
 # symbolically link $1 to $2.  Portable version of "ln -sf".
@@ -286,6 +286,10 @@ for opt do
   esac
 done
 
+EXTRA_CFLAGS=""
+EXTRA_CXXFLAGS=""
+EXTRA_LDFLAGS=""
+
 xen_ctrl_version="$default_feature"
 xfs="$default_feature"
 membarrier="$default_feature"
@@ -394,13 +398,13 @@ for opt do
   ;;
   --cpu=*) cpu="$optarg"
   ;;
-  --extra-cflags=*) QEMU_CFLAGS="$QEMU_CFLAGS $optarg"
-                    QEMU_LDFLAGS="$QEMU_LDFLAGS $optarg"
+  --extra-cflags=*)
+    EXTRA_CFLAGS="$EXTRA_CFLAGS $optarg"
+    EXTRA_CXXFLAGS="$EXTRA_CXXFLAGS $optarg"
+    ;;
+  --extra-cxxflags=*) EXTRA_CXXFLAGS="$EXTRA_CXXFLAGS $optarg"
   ;;
-  --extra-cxxflags=*) QEMU_CXXFLAGS="$QEMU_CXXFLAGS $optarg"
-  ;;
-  --extra-ldflags=*) QEMU_LDFLAGS="$QEMU_LDFLAGS $optarg"
-                     EXTRA_LDFLAGS="$optarg"
+  --extra-ldflags=*) EXTRA_LDFLAGS="$EXTRA_LDFLAGS $optarg"
   ;;
   --enable-debug-info) debug_info="yes"
   ;;
@@ -1346,8 +1350,8 @@ Advanced options (experts only):
                            build time
   --cxx=CXX                use C++ compiler CXX [$cxx]
   --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]
-  --extra-cflags=CFLAGS    append extra C compiler flags QEMU_CFLAGS
-  --extra-cxxflags=CXXFLAGS append extra C++ compiler flags QEMU_CXXFLAGS
+  --extra-cflags=CFLAGS    append extra C compiler flags CFLAGS
+  --extra-cxxflags=CXXFLAGS append extra C++ compiler flags CXXFLAGS
   --extra-ldflags=LDFLAGS  append extra linker flags LDFLAGS
   --cross-cc-ARCH=CC       use compiler when building ARCH guest test cases
   --cross-cc-flags-ARCH=   use compiler flags when building ARCH guest tests
@@ -3402,7 +3406,7 @@ EOF
 
     update_cxxflags
 
-    if do_cxx $CXXFLAGS $CONFIGURE_CXXFLAGS $QEMU_CXXFLAGS -o $TMPE $TMPCXX 
$TMPO $QEMU_LDFLAGS; then
+    if do_cxx $CXXFLAGS $EXTRA_CXXFLAGS $CONFIGURE_CXXFLAGS $QEMU_CXXFLAGS -o 
$TMPE $TMPCXX $TMPO $QEMU_LDFLAGS; then
         # C++ compiler $cxx works ok with C compiler $cc
         :
     else
@@ -3909,10 +3913,10 @@ if test "$skip_meson" = no; then
 
   test -z "$cxx" && echo "link_language = 'c'" >> $cross
   echo "[built-in options]" >> $cross
-  echo "c_args = [$(meson_quote $CFLAGS)]" >> $cross
-  echo "cpp_args = [$(meson_quote $CXXFLAGS)]" >> $cross
-  echo "c_link_args = [$(meson_quote $LDFLAGS)]" >> $cross
-  echo "cpp_link_args = [$(meson_quote $LDFLAGS)]" >> $cross
+  echo "c_args = [$(meson_quote $CFLAGS $EXTRA_CFLAGS)]" >> $cross
+  echo "cpp_args = [$(meson_quote $CXXFLAGS $EXTRA_CXXFLAGS)]" >> $cross
+  echo "c_link_args = [$(meson_quote $LDFLAGS $EXTRA_LDFLAGS)]" >> $cross
+  echo "cpp_link_args = [$(meson_quote $LDFLAGS $EXTRA_LDFLAGS)]" >> $cross
   echo "[binaries]" >> $cross
   echo "c = [$(meson_quote $cc $CPU_CFLAGS)]" >> $cross
   test -n "$cxx" && echo "cpp = [$(meson_quote $cxx $CPU_CFLAGS)]" >> $cross
-- 
2.33.1