Fixed cross compilation with mingw.

src/ports/SkOSFile_win.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkOSFile.h"
 
 #include "SkTFitsIn.h"
@@ skipping 32 matching lines @@
 }
 
 bool sk_fidentical(SkFILE* a, SkFILE* b) {
     SkFILEID aID, bID;
     return sk_ino(a, &aID) && sk_ino(b, &bID)
            && aID.fLsbSize == bID.fLsbSize
            && aID.fMsbSize == bID.fMsbSize
            && aID.fVolume == bID.fVolume;
 }
 
-template <typename HandleType, HandleType InvalidValue, BOOL (WINAPI * Close)(HandleType)>
+template <typename HandleType, LONG_PTR InvalidValue, BOOL (WINAPI * Close)(HandleType)>

[bungeman-skia, 2014/03/14 17:50:18]

So I thought maybe I could replace this with some traits, but that means that
the static const <trait>::InvalidValue would need to be initialized in a
translation unit, which I'd like to avoid (I just want to compare directly,
avoiding any possible loads).

Since we're not actually using SkAutoWinFile anyway (anymore), the only user is
actually SkAutoWinMMap, so it would be preferred at this time to just write that
one explicitly.

class SkAutoNullKernelHandle : SkNoncopyable {
public:
    SkAutoNullKernelHandle(const HANDLE handle) : fHandle(handle) { }
    ~SkAutoNullKernelHandle() { CloseHandle(fHandle); }
    operator HANDLE() const { return fHandle; }
    bool isValid() const { return NULL != fHandle; }
private:
    HANDLE fHandle;
};
typedef SkAutoNullKernelHandle SkAutoWinMMap;

Frankly, specializing isn't much more code that the traiting anyway.

 class SkAutoTHandle : SkNoncopyable {
 public:
     SkAutoTHandle(HandleType handle) : fHandle(handle) { }
     ~SkAutoTHandle() { Close(fHandle); }
     operator HandleType() { return fHandle; }
-    bool isValid() { return InvalidValue != fHandle; }
+    bool isValid() { return HandleType(InvalidValue) != fHandle; }
 private:
     HandleType fHandle;
 };
-typedef SkAutoTHandle<HANDLE, INVALID_HANDLE_VALUE, CloseHandle> SkAutoWinFile;
-typedef SkAutoTHandle<HANDLE, NULL, CloseHandle> SkAutoWinMMap;
+typedef SkAutoTHandle<HANDLE, -1 /* INVALID_HANDLE_VALUE */, CloseHandle> SkAutoWinFile;
+typedef SkAutoTHandle<HANDLE, 0 /* NULL */, CloseHandle> SkAutoWinMMap;
 
 void sk_fmunmap(const void* addr, size_t) {
     UnmapViewOfFile(addr);
 }
 
 void* sk_fdmmap(int fileno, size_t* length) {
     HANDLE file = (HANDLE)_get_osfhandle(fileno);
     if (INVALID_HANDLE_VALUE == file) {
         return NULL;
     }
@@ skipping 29 matching lines @@
 }
 
 void* sk_fmmap(SkFILE* f, size_t* length) {
     int fileno = sk_fileno(f);
     if (fileno < 0) {
         return NULL;
     }
 
     return sk_fdmmap(fileno, length);
 }