[Qemu-devel] [PATCH v2 03/43] configure: add support for --cross-cc-FOO

["Alex Bennée" <alex.bennee@linaro.org>]

This allows us to specify cross compilers for our guests. This is
useful for building test images/programs. Currently we re-run the
compile test for each target. I couldn't think of a way to cache the
value for a given arch without getting messier configure code.

The cross compiler for the guest is visible to each target as
CROSS_CC_GUEST in config-target.mak.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 configure | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/configure b/configure
index b0ae632ee4..0dca341f2a 100755
--- a/configure
+++ b/configure
@@ -453,6 +453,13 @@ vxhs=""
 libxml2=""
 docker="no"
 
+# cross compilers defaults, can be overridden with --cross-cc-ARCH
+cross_cc_aarch64="aarch64-linux-gnu-gcc"
+cross_cc_arm="arm-linux-gnueabihf-gcc"
+cross_cc_powerpc="powerpc-linux-gnu-gcc"
+
+enabled_cross_compilers=""
+
 supported_cpu="no"
 supported_os="no"
 bogus_os="no"
@@ -483,6 +490,11 @@ for opt do
   ;;
   --disable-debug-info) debug_info="no"
   ;;
+  --cross-cc-*[!a-zA-Z0-9_0]=*) error_exit "Passed bad --cross-cc-FOO option"
+  ;;
+  --cross-cc-*) cc_arch=${opt#--cross-cc-}
+                eval "cross_cc_${cc_arch}=\$optarg"
+  ;;
   esac
 done
 # OS specific
@@ -675,10 +687,12 @@ case "$cpu" in
   i386|i486|i586|i686|i86pc|BePC)
     cpu="i386"
     supported_cpu="yes"
+    cross_cc_i386=gcc
   ;;
   x86_64|amd64)
     cpu="x86_64"
     supported_cpu="yes"
+    cross_cc_x86_64=gcc
   ;;
   armv*b|armv*l|arm)
     cpu="arm"
@@ -912,6 +926,8 @@ for opt do
   ;;
   --disable-debug-info)
   ;;
+  --cross-cc-*)
+  ;;
   --enable-modules)
       modules="yes"
   ;;
@@ -6777,6 +6793,8 @@ case "$target" in
     ;;
 esac
 
+target_compiler=""
+
 mkdir -p $target_dir
 echo "# Automatically generated by configure - do not modify" > $config_target_mak
 
@@ -6805,6 +6823,7 @@ case "$target_name" in
     bflt="yes"
     mttcg="yes"
     gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
+    target_compiler=$cross_cc_arm
   ;;
   aarch64|aarch64_be)
     TARGET_ARCH=aarch64
@@ -6812,6 +6831,7 @@ case "$target_name" in
     bflt="yes"
     mttcg="yes"
     gdb_xml_files="aarch64-core.xml aarch64-fpu.xml arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
+    target_compiler=$cross_cc_aarch64
   ;;
   cris)
   ;;
@@ -6853,6 +6873,7 @@ case "$target_name" in
   ;;
   ppc)
     gdb_xml_files="power-core.xml power-fpu.xml power-altivec.xml power-spe.xml"
+    target_compiler=$cross_cc_powerpc
   ;;
   ppcemb)
     TARGET_BASE_ARCH=ppc
@@ -6927,6 +6948,25 @@ if [ "$TARGET_BASE_ARCH" = "" ]; then
   TARGET_BASE_ARCH=$TARGET_ARCH
 fi
 
+# Do we have a cross compiler for this target?
+if has $target_compiler; then
+
+    cat > $TMPC << EOF
+#include <stdio.h>
+int main(void) {
+    printf("Hello World!\n");
+}
+EOF
+
+    if ! do_compiler $target_compiler -o $TMPE $TMPC -static ; then
+        target_compiler=""
+    else
+        enabled_cross_compilers="${enabled_cross_compilers} ${target_compiler}"
+    fi
+else
+    target_compiler=""
+fi
+
 symlink "$source_path/Makefile.target" "$target_dir/Makefile"
 
 upper() {
@@ -7000,6 +7040,10 @@ if test "$target_bsd_user" = "yes" ; then
   echo "CONFIG_BSD_USER=y" >> $config_target_mak
 fi
 
+if test -n "$target_compiler"; then
+  echo "CROSS_CC_GUEST=$target_compiler" >> $config_target_mak
+fi
+
 # generate QEMU_CFLAGS/LDFLAGS for targets
 
 cflags=""
@@ -7122,6 +7166,12 @@ echo "QEMU_CFLAGS+=$cflags" >> $config_target_mak
 
 done # for target in $targets
 
+if test -n "$enabled_cross_compilers"; then
+    echo
+    echo "NOTE: cross-compilers enabled:"
+    printf '%s\n' $enabled_cross_compilers | sort -u
+fi
+
 if [ "$dtc_internal" = "yes" ]; then
   echo "config-host.h: subdir-dtc" >> $config_host_mak
 fi
-- 
2.17.0