Add support for invariant casing in PAL (#24597)

unicodedata.cpp based on UnicodeData.txt v11.0.

Author: MichalStrehovsky

src/pal/inc/pal.h

@@ -4618,6 +4618,9 @@ PALIMPORT DLLEXPORT int __cdecl _putenv(const char *);
 
 #define ERANGE          34
 
+PALIMPORT WCHAR __cdecl PAL_ToUpperInvariant(WCHAR);
+PALIMPORT WCHAR __cdecl PAL_ToLowerInvariant(WCHAR);
+
 /******************* PAL-specific I/O completion port *****************/
 
 typedef struct _PAL_IOCP_CPU_INFORMATION {

src/pal/src/CMakeLists.txt

@@ -212,6 +212,7 @@ set(SOURCES
   loader/module.cpp
   loader/modulename.cpp
   locale/unicode.cpp
+  locale/unicodedata.cpp
   locale/utf8.cpp
   map/common.cpp
   map/map.cpp

src/pal/src/include/pal/unicodedata.h

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#ifndef _PAL_UNICODEDATA_H_
+#define _PAL_UNICODEDATA_H_
+
+#include "pal/palinternal.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif // __cplusplus
+
+#define UPPER_CASE 1
+#define LOWER_CASE 2
+
+typedef struct
+{
+  WCHAR nUnicodeValue;
+  WORD  nFlag;
+  WCHAR nOpposingCase;
+} UnicodeDataRec;
+
+extern CONST UnicodeDataRec UnicodeData[];
+extern CONST UINT UNICODE_DATA_SIZE;
+
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
+#endif  /* _UNICODE_DATA_H_ */

src/pal/src/locale/unicode.cpp

@@ -29,6 +29,7 @@ Revision History:
 #include "pal/locale.h"
 #include "pal/cruntime.h"
 #include "pal/stackstring.hpp"
+#include "pal/unicodedata.h"
 
 #if !(HAVE_PTHREAD_RWLOCK_T || HAVE_COREFOUNDATION)
 #error Either pthread rwlocks or Core Foundation are required for Unicode support
@@ -79,6 +80,138 @@ static const CP_MAPPING CP_TO_NATIVE_TABLE[] = {
 // - We want Ansi marshalling to mean marshal to UTF-8 on Mac and Linux
 static const UINT PAL_ACP = 65001;
 
+/*++
+Function:
+UnicodeDataComp
+This is the comparison function used by the bsearch function to search
+for unicode characters in the UnicodeData array.
+
+Parameter:
+pnKey
+The unicode character value to search for.
+elem
+A pointer to a UnicodeDataRec.
+
+Return value:
+<0 if pnKey < elem->nUnicodeValue
+0 if pnKey == elem->nUnicodeValue
+>0 if pnKey > elem->nUnicodeValue
+--*/
+static int UnicodeDataComp(const void *pnKey, const void *elem)
+{
+    WCHAR uValue = ((UnicodeDataRec*)elem)->nUnicodeValue;
+
+    if (*((INT*)pnKey) < uValue)
+    {
+        return -1;
+    }
+    else if (*((INT*)pnKey) > uValue)
+    {
+        return 1;
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+/*++
+Function:
+GetUnicodeData
+This function is used to get information about a Unicode character.
+
+Parameters:
+nUnicodeValue
+The numeric value of the Unicode character to get information about.
+pDataRec
+The UnicodeDataRec to fill in with the data for the Unicode character.
+
+Return value:
+TRUE if the Unicode character was found.
+
+--*/
+BOOL GetUnicodeData(INT nUnicodeValue, UnicodeDataRec *pDataRec)
+{ 
+    BOOL bRet; 
+
+    UnicodeDataRec *dataRec;
+    INT nNumOfChars = UNICODE_DATA_SIZE;
+    dataRec = (UnicodeDataRec *) bsearch(&nUnicodeValue, UnicodeData, nNumOfChars,
+                   sizeof(UnicodeDataRec), UnicodeDataComp);
+    if (dataRec == NULL)
+    {
+        bRet = FALSE;
+    }
+    else
+    {
+        bRet = TRUE;
+        *pDataRec = *dataRec;
+    }
+    return bRet;
+}
+
+wchar_16
+__cdecl
+PAL_ToUpperInvariant( wchar_16 c )
+{
+    UnicodeDataRec dataRec;
+
+    PERF_ENTRY(PAL_ToUpperInvariant);
+    ENTRY("PAL_ToUpperInvariant (c=%d)\n", c);
+
+    if (!GetUnicodeData(c, &dataRec))
+    {
+        TRACE( "Unable to retrieve unicode data for the character %c.\n", c );
+        LOGEXIT("PAL_ToUpperInvariant returns int %d\n", c );
+        PERF_EXIT(PAL_ToUpperInvariant);
+        return c;
+    }
+
+    if ( dataRec.nFlag != LOWER_CASE )
+    {
+        LOGEXIT("PAL_ToUpperInvariant returns int %d\n", c );
+        PERF_EXIT(PAL_ToUpperInvariant);
+        return c;
+    }
+    else
+    {
+        LOGEXIT("PAL_ToUpperInvariant returns int %d\n", dataRec.nOpposingCase );
+        PERF_EXIT(PAL_ToUpperInvariant);
+        return dataRec.nOpposingCase;
+    }
+}
+
+wchar_16
+__cdecl
+PAL_ToLowerInvariant( wchar_16 c )
+{
+    UnicodeDataRec dataRec;
+
+    PERF_ENTRY(PAL_ToLowerInvariant);
+    ENTRY("PAL_ToLowerInvariant (c=%d)\n", c);
+
+    if (!GetUnicodeData(c, &dataRec))
+    {
+        TRACE( "Unable to retrieve unicode data for the character %c.\n", c );
+        LOGEXIT("PAL_ToLowerInvariant returns int %d\n", c );
+        PERF_EXIT(PAL_ToLowerInvariant);
+        return c;
+    }
+
+    if ( dataRec.nFlag != UPPER_CASE )
+    {
+        LOGEXIT("PAL_ToLowerInvariant returns int %d\n", c );
+        PERF_EXIT(PAL_ToLowerInvariant);
+        return c;
+    }
+    else
+    {
+        LOGEXIT("PAL_ToLowerInvariant returns int %d\n", dataRec.nOpposingCase );
+        PERF_EXIT(PAL_ToLowerInvariant);
+        return dataRec.nOpposingCase;
+    }
+}
+
 /*++
 Function:
 CODEPAGEGetData