Identifying call sites that need to handle out of memory situations in Courgette.

courgette/memory_allocator.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COURGETTE_MEMORY_ALLOCATOR_H_
 #define COURGETTE_MEMORY_ALLOCATOR_H_
 
 #include <memory>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/platform_file.h"
 
+#ifndef NDEBUG
+
+// A helper class to track down call sites that are not handling error cases.
+template<class T>
+class CheckReturnValue {
+ public:
+  // Not marked explicit on purpose.
+  CheckReturnValue(T value) : value_(value), checked_(false) {  // NOLINT
+  }
+  CheckReturnValue(const CheckReturnValue& other)
+      : value_(other.value_), checked_(other.checked_) {
+    other.checked_ = true;
+  }
+
+  CheckReturnValue& operator=(const CheckReturnValue& other) {
+    if (this != &other) {
+      DCHECK(checked_);
+      value_ = other.value_;
+      checked_ = other.checked_;
+      other.checked_ = true;
+    }
+  }
+
+  ~CheckReturnValue() {
+    DCHECK(checked_);
+  }
+
+  operator const T&() const {
+    checked_ = true;
+    return value_;
+  }
+
+ private:
+  T value_;
+  mutable bool checked_;
+};
+typedef CheckReturnValue<bool> CheckBool;
+#else
+typedef bool CheckBool;
+#endif
+
 namespace courgette {
 
 #ifdef OS_WIN
 
 // Manages a temporary file.  The file is created in the %TEMP% folder and
 // is deleted when the file handle is closed.
 // NOTE: Since the file will be used as backing for a memory allocation,
 // it will never be so big that size_t cannot represent its size.
 class TempFile {
  public:
@@ skipping 190 matching lines @@
 template<class T>
 class MemoryAllocator : public std::allocator<T> {
  public:
 };
 
 #endif  // OS_WIN
 
 }  // namespace courgette
 
 #endif  // COURGETTE_MEMORY_ALLOCATOR_H_