package libffi: bugfix for build directory and add test program

src/libffi-test.c

@@ -0,0 +1,31 @@
+/* This file is part of mingw-cross-env.       */
+/* See doc/index.html for further information. */
+
+#include <stdio.h>
+#include <ffi.h>
+
+int main(int argc, char *argv[])
+{
+    ffi_cif cif;
+    ffi_type *args[1];
+    void *values[1];
+    char *s;
+    int rc;
+    
+    (void)argc;
+    (void)argv;
+
+    args[0] = &ffi_type_pointer;
+    values[0] = &s;
+
+    if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1,
+    		       &ffi_type_uint, args) == FFI_OK)
+    {
+        s = "Hello World!";
+        ffi_call(&cif, FFI_FN(puts), &rc, values);
+        s = "Goodbye!";
+        ffi_call(&cif, FFI_FN(puts), &rc, values);
+    }
+
+    return 0;
+}

src/libffi.mk

@@ -24,6 +24,11 @@ define $(PKG)_BUILD
         --host='$(TARGET)' \
         --prefix='$(PREFIX)/$(TARGET)' \
         --disable-shared
-    $(MAKE) -C '$(1)' -j '$(JOBS)'
-    $(MAKE) -C '$(1)' -j 1 install
+    $(MAKE) -C '$(1)/$(TARGET)' -j '$(JOBS)'
+    $(MAKE) -C '$(1)/$(TARGET)' -j 1 install
+
+    '$(TARGET)-gcc' \
+        -W -Wall -Werror -std=c99 -pedantic \
+        '$(2).c' -o '$(PREFIX)/$(TARGET)/bin/test-libffi.exe' \
+        `'$(TARGET)-pkg-config' libffi --cflags --libs`
 endef