Support long paths in CoreCLR runtime on Windows

The CoreCLR runtime is updated to support long file paths on Windows.
Pending updates to mscorlib.dll, the following scenarios are supported:
* Run managed apps from a long path.
* Load CoreCLR runtime and framework from a long path.
* Load user assemblies from a long path.
* Run CrossGen from a long path, with its input/output from a long path.
* Generate debug log file at a long path.

The following scenarios are not yet supported, and will be fixed in
future commits:
* Mscorlib.dll and framework assemblies are not yet long path compatible.
  Note that until mscorlib.dll is fixed, most of the runtime changes can't
  actually be used.
* Support on non-Windows platforms.
* Support for debugging and error reporting.
* Tools such as ilasm or ildasm.

1 files changed, 12 insertions, 25 deletions

diff --git a/src/utilcode/splitpath.cpp b/src/utilcode/splitpath.cpp
index 927e8828e1..f7a35fdd97 100644
--- a/src/utilcode/splitpath.cpp
+++ b/src/utilcode/splitpath.cpp
@@ -124,7 +124,7 @@ void    SplitPathInterior(
 
     /* extract drive letter and :, if any */
 
-    if ((wcslen(wszPath) >= (_MAX_DRIVE - 2)) && (*(wszPath + _MAX_DRIVE - 2) == _T(':'))) {
+    if ((wcslen(wszPath) > (_MAX_DRIVE - 2)) && (*(wszPath + _MAX_DRIVE - 2) == _T(':'))) {
         if (pwszDrive && pcchDrive) {
             *pwszDrive = wszPath;
             *pcchDrive = _MAX_DRIVE - 1;
@@ -243,38 +243,25 @@ void    SplitPath(__in SString const &path,
                   __inout_opt SString *fname,
                   __inout_opt SString *ext)
 {
-    LPWSTR wzDrive = NULL;
-    if (drive != NULL)
-        wzDrive = drive->OpenUnicodeBuffer(_MAX_DRIVE);
-
-    LPWSTR wzDir = NULL;
-    if (dir != NULL)
-        wzDir = dir->OpenUnicodeBuffer(_MAX_DIR);
-
-    LPWSTR wzFname = NULL;
-    if (fname != NULL)
-        wzFname = fname->OpenUnicodeBuffer(_MAX_FNAME);
-
-    LPWSTR wzExt = NULL;
-    if (ext != NULL)
-        wzExt = ext->OpenUnicodeBuffer(_MAX_EXT);
+    LPCWSTR wzDrive, wzDir, wzFname, wzExt;
+    size_t cchDrive, cchDir, cchFname, cchExt;
 
-    SplitPath(path,
-            wzDrive, _MAX_DRIVE,
-            wzDir, _MAX_DIR,
-            wzFname, _MAX_FNAME,
-            wzExt, _MAX_EXT);
+    SplitPathInterior(path,
+            &wzDrive, &cchDrive,
+            &wzDir, &cchDir,
+            &wzFname, &cchFname,
+            &wzExt, &cchExt);
 
     if (drive != NULL)
-        drive->CloseBuffer(static_cast<COUNT_T>(wcslen(wzDrive)));
+        drive->Set(wzDrive, (COUNT_T)cchDrive);
 
     if (dir != NULL)
-        dir->CloseBuffer(static_cast<COUNT_T>(wcslen(wzDir)));
+        dir->Set(wzDir, (COUNT_T)cchDir);
 
     if (fname != NULL)
-        fname->CloseBuffer(static_cast<COUNT_T>(wcslen(wzFname)));
+        fname->Set(wzFname, (COUNT_T)cchFname);
 
     if (ext != NULL)
-        ext->CloseBuffer(static_cast<COUNT_T>(wcslen(wzExt)));
+        ext->Set(wzExt, (COUNT_T)cchExt);
 }