[PATCH v2 1/2] ucrtbase/tests: Test some details about rewind's ABI.

[Victor Chiletto]

From: Victor Chiletto

More specifically: a mod for Fallout: New Vegas relies on rewind not
modifying the first argument passed to it [1].

[1]: https://github.com/jazzisparis/UIO-User-Interface-Organizer/blob/426d96391f9...
---
 dlls/ucrtbase/tests/misc.c | 42 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/dlls/ucrtbase/tests/misc.c b/dlls/ucrtbase/tests/misc.c
index 069de0787b7..1371bc79b32 100644
--- a/dlls/ucrtbase/tests/misc.c
+++ b/dlls/ucrtbase/tests/misc.c
@@ -38,6 +38,10 @@
 #include <winbase.h>
 #include "wine/test.h"

+#if defined(__i386__) && defined(__GNUC__)
+#include "wine/asm.h"
+#endif
+
 #define DEFINE_EXPECT(func) \
     static BOOL expect_ ## func = FALSE, called_ ## func = FALSE

@@ -1591,6 +1595,41 @@ static void test_fopen_exclusive( void )
     unlink(path);
 }

+#if defined(__i386__)
+#if defined(__GNUC__)
+extern CDECL FILE *test_rewind_wrapper(FILE *fp);
+__ASM_GLOBAL_FUNC(test_rewind_wrapper,
+    "pushl 4(%esp)\n\t"
+    "call " __ASM_NAME("rewind") "\n\t"
+    "popl %eax\n\t"
+    "ret")
+#else
+FILE* CDECL test_rewind_wrapper(FILE* fp);
+__declspec(naked) FILE* test_rewind_wrapper(FILE *fp)
+{
+    __asm
+    {
+        push [esp + 4];
+        call rewind;
+        pop eax;
+        ret;
+    }
+}
+#endif
+
+static void test_rewind_i386_abi(void)
+{
+    FILE *fp_in, *fp_out;
+
+    fp_in = fopen("rewind_abi.tst", "wb");
+    fp_out = test_rewind_wrapper(fp_in);
+    todo_wine ok(fp_in == fp_out, "rewind modified the first argument in the stack\n");
+
+    fclose(fp_in);
+    unlink("rewind_abi.tst");
+}
+#endif
+
 START_TEST(misc)
 {
     int arg_c;
@@ -1633,4 +1672,7 @@ START_TEST(misc)
     test_thread_storage();
     test_fenv();
     test_fopen_exclusive();
+#if defined(__i386__)
+    test_rewind_i386_abi();
+#endif
 }