[tkreuzer] 70429: [CRT_APITEST] Add another test for strlen, that tests, whether the direction flag in ELFAGS has been modified. While clearing it is legitimate to do according to the ABI, the nati...

Author: tkreuzer
Date: Sat Dec 26 20:32:31 2015
New Revision: 70429

URL: http://svn.reactos.org/svn/reactos?rev=70429&view=rev
Log:
[CRT_APITEST]
Add another test for strlen, that tests, whether the direction flag in ELFAGS has been
modified. While clearing it is legitimate to do according to the ABI, the native
implementation does not change it, so we don't want to do it either.

Modified:
    trunk/rostests/apitests/crt/strlen.c

Modified: trunk/rostests/apitests/crt/strlen.c
URL:
http://svn.reactos.org/svn/reactos/trunk/rostests/apitests/crt/strlen.c?rev…
==============================================================================
--- trunk/rostests/apitests/crt/strlen.c	[iso-8859-1] (original)
+++ trunk/rostests/apitests/crt/strlen.c	[iso-8859-1] Sat Dec 26 20:32:31 2015
@@ -23,12 +23,18 @@
 }
 #endif
 
+#define EFLAGS_DF 0x400L
+
 typedef size_t (*PFN_STRLEN)(const char *);
 
 void
 Test_strlen(PFN_STRLEN pstrlen)
 {
     size_t len;
+#if defined(_M_IX86) || defined(_M_AMD64)
+    volatile uintptr_t eflags;
+    char *teststr = "a\0bcdefghijk";
+#endif
 
     /* basic parameter tests */
     StartSeh()
@@ -37,6 +43,21 @@
     (void)len;
 
     ok_int((int)pstrlen("test"), 4);
+
+#if defined(_M_IX86) || defined(_M_AMD64)
+    eflags = __readeflags();
+    __writeeflags(eflags | EFLAGS_DF);
+    len = pstrlen(teststr + 4);
+    eflags = __readeflags();
+    ok((eflags & EFLAGS_DF) != 0, "Direction flag in ELFAGS was
changed.");
+
+    /* Only test this for the exported versions, intrinsics might do it
+       differently. It's up to us to not do fishy stuff! */
+    if (pstrlen == strlen)
+    {
+        ok(len == 8, "Should not have gone backwards (got len %i)", (int)len);
+    }
+#endif
 }
 
 START_TEST(strlen)