Re: [PATCH 4/4] configure: ignore preexisting QEMU_*FLAGS envvars

[Paolo Bonzini]

On 11/8/21 10:17, Philippe Mathieu-Daudé wrote:
-    QEMU_CXXFLAGS="$QEMU_CXXFLAGS -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS 
-D__STDC_FORMAT_MACROS"
+    QEMU_CXXFLAGS="-D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS 
-D__STDC_FORMAT_MACROS"
      CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed 
s/-std=gnu11/-std=gnu++11/)
      for arg in $QEMU_CFLAGS; do
          case $arg in
update_cxxflags() should keep previous QEMU_CXXFLAGS. But since
we call it only once, we don't use it to update. IMHO we should
inline this code where it is called, then overwriting QEMU_CXXFLAGS
makes sense.

With Meson 0.60 it's possible to link-test a C source with a C++ 
compiler and then all this stuff (including the link_language detection) 
can be moved to the proper place.

Paolo