8001942: build-infra: General permission problems on Windows/cygwin

Summary: Added sanity check for file permissions in configure
Reviewed-by: tbell, ohair

common/autoconf/basics.m4

@@ -633,6 +633,18 @@ AC_DEFUN([BASIC_CHECK_DIR_ON_LOCAL_DISK],
   fi
 ])
 
+# Check that source files have basic read permissions set. This might
+# not be the case in cygwin in certain conditions.
+AC_DEFUN_ONCE([BASIC_CHECK_SRC_PERMS],
+[
+  if test x"$OPENJDK_BUILD_OS" = xwindows; then
+    file_to_test="$SRC_ROOT/LICENSE"
+    if test `$STAT -c '%a' "$file_to_test"` -lt 400; then
+      AC_MSG_ERROR([Bad file permissions on src files. This is usually caused by cloning the repositories with a non cygwin hg in a directory not created in cygwin.])
+    fi
+  fi
+])
+
 AC_DEFUN_ONCE([BASIC_TEST_USABILITY_ISSUES],
 [
 
@@ -642,6 +654,8 @@ BASIC_CHECK_DIR_ON_LOCAL_DISK($OUTPUT_ROOT,
   [OUTPUT_DIR_IS_LOCAL="no"])
 AC_MSG_RESULT($OUTPUT_DIR_IS_LOCAL)
 
+BASIC_CHECK_SRC_PERMS
+
 # Check if the user has any old-style ALT_ variables set.
 FOUND_ALT_VARIABLES=`env | grep ^ALT_`