[PATCH 1 of 4 v2] auto/type/sizeof: rework autotest to be cross-compilation friendly

[Samuel Martin]

# HG changeset patch
# User Samuel Martin <s.martin49 at gmail.com>
# Date 1401633266 -7200
#      Sun Jun 01 16:34:26 2014 +0200
# Branch sma/cross-compilation
# Node ID e52b6d1510a8ce2570d29c56738189485e9c9a1e
# Parent  b9553b4b8e670a0231afc0484f23953c0d8b5f22
auto/type/sizeof: rework autotest to be cross-compilation friendly
Rework the sizeof test to do the checks at compile time instead of at
runtime. This way, it does not break when cross-compiling for a
different CPU architecture.

diff -r b9553b4b8e67 -r e52b6d1510a8 auto/types/sizeof
--- a/auto/types/sizeof	Tue Apr 29 22:22:38 2014 +0200
+++ b/auto/types/sizeof	Sun Jun 01 16:34:26 2014 +0200
@@ -14,7 +14,7 @@
 
 ngx_size=
 
-cat << END > $NGX_AUTOTEST.c
+cat << _EOF > $NGX_AUTOTEST.c
 
 #include <sys/types.h>
 #include <sys/time.h>
@@ -25,28 +25,42 @@
 $NGX_INCLUDE_INTTYPES_H
 $NGX_INCLUDE_AUTO_CONFIG_H
 
-int main() {
-    printf("%d", (int) sizeof($ngx_type));
+#if !defined( PASTE)
+#define PASTE2( x, y) x##y
+#define PASTE( x, y)  PASTE2( x, y)
+#endif /* PASTE */
+
+#define SAY_IF_SIZEOF( typename, type, size)   \\
+    static char PASTE( PASTE( PASTE( sizeof_, typename), _is_), size) \\
+    [(sizeof(type) == (size)) ? 1 : -1]
+
+SAY_IF_SIZEOF(TEST_TYPENAME, TEST_TYPE, TEST_SIZE);
+
+int main(void)
+{
     return 0;
 }
 
-END
+_EOF
 
-
-ngx_test="$CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
-          -o $NGX_AUTOTEST $NGX_AUTOTEST.c $NGX_LD_OPT $ngx_feature_libs"
-
-eval "$ngx_test >> $NGX_AUTOCONF_ERR 2>&1"
-
-
-if [ -x $NGX_AUTOTEST ]; then
-    ngx_size=`$NGX_AUTOTEST`
-    echo " $ngx_size bytes"
-fi
-
+_ngx_typename=`echo "$ngx_type" | sed 's/ /_/g;s/\*/p/'`
+ngx_size="-1"
+ngx_size=`for i in 1 2 4 8 16 ; do \
+    $CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
+    -DTEST_TYPENAME="$_ngx_typename" -DTEST_TYPE="$ngx_type" -DTEST_SIZE="$i" \
+    $NGX_AUTOTEST.c -o $NGX_AUTOTEST \
+    $NGX_LD_OPT $ngx_feature_libs &>/dev/null || continue ;\
+    echo $i ; break ; done`
 
 rm -rf $NGX_AUTOTEST*
 
+if test -z $ngx_size ; then
+    ngx_size=-1
+fi
+
+if [ $ngx_size -gt 0 ]; then
+    echo " $ngx_size bytes"
+fi
 
 case $ngx_size in
     4)