[Qemu-devel] [PATCH v4] configure: do CC check before verifying host CPU

[Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>]

When executing 'configure' in a fresh QEMU clone, in a fresh
OS install running in a ppc64le host, this is the error
shown:

-----

../configure --enable-trace-backend=simple --enable-debug
    --target-list=ppc64-softmmu

ERROR: Unsupported CPU = ppc64le, try --enable-tcg-interpreter

-----

This isn't true, ppc64le host CPU is supported. This happens because,
in a fresh install, we don't have a C compiler to autodetect
the $cpu variable to "ppc64".

Since we need a C compiler to properly get the value of $cpu
in this and other cases, this patch changes the location of the C
compiler check right after setting the preferred CC.

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
---
 configure | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/configure b/configure
index 285d123dbf..a641bf18b6 100755
--- a/configure
+++ b/configure
@@ -467,6 +467,23 @@ else
   cc="${CC-${cross_prefix}gcc}"
 fi
 
+write_c_skeleton() {
+    cat > $TMPC <<EOF
+int main(void) { return 0; }
+EOF
+}
+
+# check that the C compiler works.
+write_c_skeleton;
+if compile_object ; then
+  : C compiler works ok
+else
+    error_exit "\"$cc\" either does not exist or does not work"
+fi
+if ! compile_prog ; then
+    error_exit "\"$cc\" cannot build an executable (is your linker broken?)"
+fi
+
 if test -z "${CXX}${cross_prefix}"; then
   cxx="c++"
 else
@@ -537,12 +554,6 @@ EOF
   compile_object
 }
 
-write_c_skeleton() {
-    cat > $TMPC <<EOF
-int main(void) { return 0; }
-EOF
-}
-
 if check_define __linux__ ; then
   targetos="Linux"
 elif check_define _WIN32 ; then
@@ -1593,17 +1604,6 @@ if test -z "$werror" ; then
     fi
 fi
 
-# check that the C compiler works.
-write_c_skeleton;
-if compile_object ; then
-  : C compiler works ok
-else
-    error_exit "\"$cc\" either does not exist or does not work"
-fi
-if ! compile_prog ; then
-    error_exit "\"$cc\" cannot build an executable (is your linker broken?)"
-fi
-
 if test "$bogus_os" = "yes"; then
     # Now that we know that we're not printing the help and that
     # the compiler works (so the results of the check_defines we used
-- 
2.13.6