ntdll: Reimplement qsort() using generic mergesort.

dlls/ntdll/misc.c

@@ -2,6 +2,7 @@
  * Helper functions for ntdll
  *
  * Copyright 2000 Juergen Schmied
+ * Copyright 2010 Marcus Meissner
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -250,3 +251,45 @@ double CDECL NTDLL_tan( double d )
 {
     return tan( d );
 }
+
+
+/* Merge Sort. Algorithm taken from http://www.linux-related.de/index.html?/coding/sort/sort_merge.htm */
+static void mergesort( void *arr, void *barr, int elemsize, int(__cdecl *compar)(const void *, const void *),
+                       int left, int right )
+{
+    if(right>left) {
+        int i, j, k, m;
+        m=(right+left)/2;
+        mergesort( arr, barr, elemsize, compar, left, m);
+        mergesort( arr, barr, elemsize, compar, m+1, right);
+
+#define X(a,i) ((char*)a+elemsize*(i))
+        for (i=m+1; i>left; i--)
+            memcpy (X(barr,(i-1)),X(arr,(i-1)),elemsize);
+        for (j=m; j<right; j++)
+            memcpy (X(barr,(right+m-j)),X(arr,(j+1)),elemsize);
+
+        for (k=left; k<=right; k++) {
+            /*arr[k]=(barr[i]<barr[j])?barr[i++]:barr[j--];*/
+            if (compar(X(barr,i),X(barr,j))<0) {
+                memcpy(X(arr,k),X(barr,i),elemsize);
+                i++;
+            } else {
+                memcpy(X(arr,k),X(barr,j),elemsize);
+                j--;
+            }
+        }
+    }
+#undef X
+}
+
+/*********************************************************************
+ *                  qsort   (NTDLL.@)
+ */
+void __cdecl NTDLL_qsort( void *base, size_t nmemb, size_t size,
+                          int(__cdecl *compar)(const void *, const void *) )
+{
+    void *secondarr = RtlAllocateHeap (GetProcessHeap(), 0, nmemb*size);
+    mergesort( base, secondarr, size, compar, 0, nmemb-1 );
+    RtlFreeHeap (GetProcessHeap(),0, secondarr);
+}

dlls/ntdll/string.c

@@ -92,16 +92,6 @@ void * __cdecl NTDLL_bsearch( const void *key, const void *base, size_t nmemb,
 }
 
 
-/*********************************************************************
- *                  qsort   (NTDLL.@)
- */
-void __cdecl NTDLL_qsort( void *base, size_t nmemb, size_t size,
-                          int(*compar)(const void *, const void *) )
-{
-    qsort( base, nmemb, size, compar );
-}
-
-
 /*********************************************************************
  *                  _lfind   (NTDLL.@)
  */

dlls/ntdll/tests/string.c

@@ -57,6 +57,9 @@ static ULONG    (WINAPIV *pwcstoul)(LPCWSTR, LPWSTR *, INT);
 static LPWSTR   (WINAPIV *p_wcschr)(LPCWSTR, WCHAR);
 static LPWSTR   (WINAPIV *p_wcsrchr)(LPCWSTR, WCHAR);
 
+static void     (__cdecl *p_qsort)(void *,size_t,size_t, int(__cdecl *compar)(const void *, const void *) );
+
+
 static void InitFunctionPtrs(void)
 {
     hntdll = LoadLibraryA("ntdll.dll");
@@ -90,6 +93,7 @@ static void InitFunctionPtrs(void)
 
 	p_wcschr= (void *)GetProcAddress(hntdll, "wcschr");
 	p_wcsrchr= (void *)GetProcAddress(hntdll, "wcsrchr");
+	p_qsort= (void *)GetProcAddress(hntdll, "qsort");
     } /* if */
 }
 
@@ -1137,6 +1141,59 @@ static void test_wcsrchr(void)
        "wcsrchr should have returned NULL\n");
 }
 
+static __cdecl int intcomparefunc(const void *a, const void*b)
+{
+	return (*(int*)a) - (*(int*)b);
+}
+
+static __cdecl int charcomparefunc(const void *a, const void*b)
+{
+	return (*(char*)a) - (*(char*)b);
+}
+
+static __cdecl int strcomparefunc(const void *a, const void*b)
+{
+	return lstrcmpA(*(char**)a,*(char**)b);
+}
+
+static void test_qsort(void)
+{
+    int arr[5] = { 23, 42, 8, 4, 16 };
+    char carr[5] = { 42, 23, 4, 8, 16 };
+    const char *strarr[7] = {
+	"Hello",
+	"Wine",
+	"World",
+	"!",
+	"Hopefully",
+	"Sorted",
+	"."
+    };
+
+    p_qsort ((void*)arr, 5, sizeof(int), intcomparefunc);
+    ok(arr[0] == 4,  "badly sorted, arr[0] is %d\n", arr[0]);
+    ok(arr[1] == 8,  "badly sorted, arr[1] is %d\n", arr[1]);
+    ok(arr[2] == 16, "badly sorted, arr[2] is %d\n", arr[2]);
+    ok(arr[3] == 23, "badly sorted, arr[3] is %d\n", arr[3]);
+    ok(arr[4] == 42, "badly sorted, arr[4] is %d\n", arr[4]);
+
+    p_qsort ((void*)carr, 5, sizeof(char), charcomparefunc);
+    ok(carr[0] == 4,  "badly sorted, carr[0] is %d\n", carr[0]);
+    ok(carr[1] == 8,  "badly sorted, carr[1] is %d\n", carr[1]);
+    ok(carr[2] == 16, "badly sorted, carr[2] is %d\n", carr[2]);
+    ok(carr[3] == 23, "badly sorted, carr[3] is %d\n", carr[3]);
+    ok(carr[4] == 42, "badly sorted, carr[4] is %d\n", carr[4]);
+
+    p_qsort ((void*)strarr, 7, sizeof(char*), strcomparefunc);
+    ok(!strcmp(strarr[0],"!"),  "badly sorted, strarr[0] is %s\n", strarr[0]);
+    ok(!strcmp(strarr[1],"."),  "badly sorted, strarr[1] is %s\n", strarr[1]);
+    ok(!strcmp(strarr[2],"Hello"),  "badly sorted, strarr[2] is %s\n", strarr[2]);
+    ok(!strcmp(strarr[3],"Hopefully"),  "badly sorted, strarr[3] is %s\n", strarr[3]);
+    ok(!strcmp(strarr[4],"Sorted"),  "badly sorted, strarr[4] is %s\n", strarr[4]);
+    ok(!strcmp(strarr[5],"Wine"),  "badly sorted, strarr[5] is %s\n", strarr[5]);
+    ok(!strcmp(strarr[6],"World"),  "badly sorted, strarr[6] is %s\n", strarr[6]);
+}
+
 START_TEST(string)
 {
     InitFunctionPtrs();
@@ -1165,4 +1222,6 @@ START_TEST(string)
         test_atoi();
     if (patol)
         test_atol();
+    if (p_qsort)
+        test_qsort();
 }