diff mbox series

[3/4] configure: do not clobber environment CFLAGS/CXXFLAGS/LDFLAGS

Message ID 20200920093016.1150346-4-pbonzini@redhat.com
State New
Headers show
Series configure: bugfixes and cleanups for CFLAGS | expand

Commit Message

Paolo Bonzini Sept. 20, 2020, 9:30 a.m. UTC 
If the CFLAGS, CXXFLAGS or LDFLAGS variables are present in the environment,
any modification made within the configure script is passed down to Meson.
This is particularly undesirable for the "-pie" option, since it overrides
"-shared" and thus messes up the linker flags for shared modules.

Using a separate variable therefore fixes the bug, while clarifying that
the scope of these CFLAGS is just the configure script.

Reported-by: Frederic Bezies
Analyzed-by: Toolybird
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 configure | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

Comments

Richard Henderson Sept. 20, 2020, 11:20 p.m. UTC | #1 
On 9/20/20 2:30 AM, Paolo Bonzini wrote:
> If the CFLAGS, CXXFLAGS or LDFLAGS variables are present in the environment,
> any modification made within the configure script is passed down to Meson.
> This is particularly undesirable for the "-pie" option, since it overrides
> "-shared" and thus messes up the linker flags for shared modules.
> 
> Using a separate variable therefore fixes the bug, while clarifying that
> the scope of these CFLAGS is just the configure script.
> 
> Reported-by: Frederic Bezies
> Analyzed-by: Toolybird
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/configure b/configure
index 5fabc77fb3..9a0bbd2a69 100755
--- a/configure
+++ b/configure
@@ -155,7 +155,7 @@  update_cxxflags() {
     # options which some versions of GCC's C++ compiler complain about
     # because they only make sense for C programs.
     QEMU_CXXFLAGS="$QEMU_CXXFLAGS -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS"
-    CXXFLAGS=$(echo "$CFLAGS" | sed s/-std=gnu99/-std=gnu++11/)
+    CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed s/-std=gnu99/-std=gnu++11/)
     for arg in $QEMU_CFLAGS; do
         case $arg in
             -Wstrict-prototypes|-Wmissing-prototypes|-Wnested-externs|\
@@ -170,13 +170,14 @@  update_cxxflags() {
 
 compile_object() {
   local_cflags="$1"
-  do_cc $CFLAGS $QEMU_CFLAGS $local_cflags -c -o $TMPO $TMPC
+  do_cc $CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags -c -o $TMPO $TMPC
 }
 
 compile_prog() {
   local_cflags="$1"
   local_ldflags="$2"
-  do_cc $CFLAGS $QEMU_CFLAGS $local_cflags -o $TMPE $TMPC $LDFLAGS $QEMU_LDFLAGS $local_ldflags
+  do_cc $CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags -o $TMPE $TMPC \
+      $LDFLAGS $CONFIGURE_LDFLAGS $QEMU_LDFLAGS $local_ldflags
 }
 
 # symbolically link $1 to $2.  Portable version of "ln -sf".
@@ -632,7 +633,10 @@  QEMU_CFLAGS="-Wstrict-prototypes -Wredundant-decls $QEMU_CFLAGS"
 QEMU_CFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $QEMU_CFLAGS"
 QEMU_INCLUDES="-iquote . -iquote ${source_path} -iquote ${source_path}/accel/tcg -iquote ${source_path}/include"
 QEMU_INCLUDES="$QEMU_INCLUDES -iquote ${source_path}/disas/libvixl"
-CFLAGS="-std=gnu99 -Wall"
+
+# Flags that are needed during configure but later taken care of by Meson
+CONFIGURE_CFLAGS="-std=gnu99 -Wall"
+CONFIGURE_LDFLAGS=
 
 
 check_define() {
@@ -960,7 +964,7 @@  if test "$mingw32" = "yes" ; then
   EXESUF=".exe"
   HOST_DSOSUF=".dll"
   # MinGW needs -mthreads for TLS and macro _MT.
-  CFLAGS="-mthreads $CFLAGS"
+  CONFIGURE_CFLAGS="-mthreads $CONFIGURE_CFLAGS"
   write_c_skeleton;
   prefix="/qemu"
   qemu_suffix=""
@@ -2230,7 +2234,7 @@  fi
 
 if test "$static" = "yes"; then
   if test "$pie" != "no" && compile_prog "-Werror -fPIE -DPIE" "-static-pie"; then
-    CFLAGS="-fPIE -DPIE $CFLAGS"
+    CONFIGURE_CFLAGS="-fPIE -DPIE $CONFIGURE_CFLAGS"
     QEMU_LDFLAGS="-static-pie $QEMU_LDFLAGS"
     pie="yes"
   elif test "$pie" = "yes"; then
@@ -2240,11 +2244,11 @@  if test "$static" = "yes"; then
     pie="no"
   fi
 elif test "$pie" = "no"; then
-  CFLAGS="$CFLAGS_NOPIE $CFLAGS"
-  LDFLAGS="$LDFLAGS_NOPIE $LDFLAGS"
+  CONFIGURE_CFLAGS="$CFLAGS_NOPIE $CONFIGURE_CFLAGS"
+  CONFIGURE_LDFLAGS="$LDFLAGS_NOPIE $CONFIGURE_LDFLAGS"
 elif compile_prog "-Werror -fPIE -DPIE" "-pie"; then
-  CFLAGS="-fPIE -DPIE $CFLAGS"
-  LDFLAGS="-pie $LDFLAGS"
+  CONFIGURE_CFLAGS="-fPIE -DPIE $CONFIGURE_CFLAGS"
+  CONFIGURE_LDFLAGS="-pie $CONFIGURE_LDFLAGS"
   pie="yes"
 elif test "$pie" = "yes"; then
   error_exit "PIE not available due to missing toolchain support"
@@ -3808,7 +3812,7 @@  EOF
 if ! compile_prog "$glib_cflags -Werror" "$glib_libs" ; then
     if cc_has_warning_flag "-Wno-unknown-attributes"; then
         glib_cflags="-Wno-unknown-attributes $glib_cflags"
-        CFLAGS="-Wno-unknown-attributes $CFLAGS"
+        CONFIGURE_CFLAGS="-Wno-unknown-attributes $CONFIGURE_CFLAGS"
     fi
 fi
 
@@ -3828,7 +3832,7 @@  EOF
 if ! compile_prog "$glib_cflags -Werror" "$glib_libs" ; then
     if cc_has_warning_flag "-Wno-unused-function"; then
         glib_cflags="$glib_cflags -Wno-unused-function"
-        CFLAGS="$CFLAGS -Wno-unused-function"
+        CONFIGURE_CFLAGS="$CONFIGURE_CFLAGS -Wno-unused-function"
     fi
 fi
 
@@ -6359,7 +6363,7 @@  EOF
 
     update_cxxflags
 
-    if do_cxx $CXXFLAGS $QEMU_CXXFLAGS -o $TMPE $TMPCXX $TMPO $QEMU_LDFLAGS; then
+    if do_cxx $CONFIGURE_CXXFLAGS $QEMU_CXXFLAGS -o $TMPE $TMPCXX $TMPO $QEMU_LDFLAGS; then
         # C++ compiler $cxx works ok with C compiler $cc
         :
     else