[compiler-rt][profile] Accept Unicode profile names on Windows

This addresses a small FIXME: when opening a profile file
on Windows, we now use `CreateFileW` instead of `CreateFileA`.

This fixes a relatively niche scenario in which the profile
file contains Unicode codepoints that `CreateFileA` can't handle.

I've also added a small test for `lprofOpenFileEx`
that exercises the change.

Signed-off-by: William Woodruff <william@yossarian.net>

Author: woodruffw

compiler-rt/lib/profile/InstrProfilingUtil.c

@@ -237,10 +237,26 @@ COMPILER_RT_VISIBILITY FILE *lprofOpenFileEx(const char *ProfileName) {
 
   f = fdopen(fd, "r+b");
 #elif defined(_WIN32)
-  // FIXME: Use the wide variants to handle Unicode filenames.
-  HANDLE h = CreateFileA(ProfileName, GENERIC_READ | GENERIC_WRITE,
+  int WideLength = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS,
+                                       ProfileName, -1, NULL, 0);
+  if (WideLength == 0)
+    return NULL;
+
+  WCHAR *WideProfileName =
+      (WCHAR *)malloc((size_t)WideLength * sizeof(*WideProfileName));
+  if (!WideProfileName)
+    return NULL;
+
+  if (MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, ProfileName, -1,
+                          WideProfileName, WideLength) == 0) {
+    free(WideProfileName);
+    return NULL;
+  }
+
+  HANDLE h = CreateFileW(WideProfileName, GENERIC_READ | GENERIC_WRITE,
                          FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_ALWAYS,
                          FILE_ATTRIBUTE_NORMAL, 0);
+  free(WideProfileName);
   if (h == INVALID_HANDLE_VALUE)
     return NULL;
 

compiler-rt/test/profile/Windows/instrprof-file-ex-unicode.c

@@ -0,0 +1,22 @@
+// RUN: %clang_profgen -o %t.exe %s
+// RUN: rm -rf %t.dir
+// RUN: mkdir %t.dir
+// RUN: cd %t.dir
+// RUN: %run %t.exe
+
+#include <stdio.h>
+#include <windows.h>
+
+extern FILE *lprofOpenFileEx(const char *);
+
+int main(void) {
+  const char *Filename = "profile-\xe6\x97\xa5.dump";
+  FILE *File = lprofOpenFileEx(Filename);
+  if (!File)
+    return 1;
+
+  fputs("profile data", File);
+  fclose(File);
+
+  return GetFileAttributesW(L"profile-\u65e5.dump") == INVALID_FILE_ATTRIBUTES;
+}