Refactor code in preparation of merging with the fork in Chromium OS.

This patch is part of a bigger patch that helps merging the breakpad code
with the modified version in Chromium OS.

Specifically, this patch makes the following changes:
1. Add a MemoryRange class for encapsulating and checking read access
   to a contiguous range of memory.
2. Add a MemoryMappedFile class for mapping a file into memory for
   read-only access.
3. Refactor other source code to use MemoryMappedFile.

BUG=455
TEST=Tested the following:
1. Build on 32-bit and 64-bit Linux with gcc 4.4.3 and gcc 4.6.
2. Build on Mac OS X 10.6.8 with gcc 4.2 and clang 3.0 (with latest gmock).
3. All unit tests pass.
4. Run minidump-2-core to covnert a minidump file to a core file.
Review URL: http://breakpad.appspot.com/332001

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@895 4c0a9323-5329-0410-9bdc-e9ce6186880e

1 files changed, 193 insertions, 0 deletions

diff --git a/src/common/memory_range_unittest.cc b/src/common/memory_range_unittest.cc
new file mode 100644
index 00000000..f0831e85
--- /dev/null
+++ b/src/common/memory_range_unittest.cc
@@ -0,0 +1,193 @@
+// Copyright (c) 2011, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// memory_range_unittest.cc: Unit tests for google_breakpad::MemoryRange.
+
+#include "breakpad_googletest_includes.h"
+#include "common/memory_range.h"
+
+using google_breakpad::MemoryRange;
+using testing::Message;
+
+namespace {
+
+const u_int32_t kBuffer[10] = { 0 };
+const size_t kBufferSize = sizeof(kBuffer);
+const u_int8_t* kBufferPointer = reinterpret_cast<const u_int8_t*>(kBuffer);
+
+// Test vectors for verifying Covers, GetData, and Subrange.
+const struct {
+  bool valid;
+  size_t offset;
+  size_t length;
+} kSubranges[] = {
+  { true, 0, 0 },
+  { true, 0, 2 },
+  { true, 0, kBufferSize },
+  { true, 2, 0 },
+  { true, 2, 4 },
+  { true, 2, kBufferSize - 2 },
+  { true, kBufferSize - 1, 1 },
+  { false, kBufferSize, 0 },
+  { false, kBufferSize, -1 },
+  { false, kBufferSize + 1, 0 },
+  { false, -1, 2 },
+  { false, 1, kBufferSize },
+  { false, kBufferSize - 1, 2 },
+  { false, 0, -1 },
+  { false, 1, -1 },
+};
+const size_t kNumSubranges = sizeof(kSubranges) / sizeof(kSubranges[0]);
+
+// Test vectors for verifying GetArrayElement.
+const struct {
+  size_t offset;
+  size_t size;
+  size_t index;
+  const void* const pointer;
+} kElements[] = {
+  // Valid array elemenets
+  { 0, 1, 0, kBufferPointer },
+  { 0, 1, 1, kBufferPointer + 1 },
+  { 0, 1, kBufferSize - 1, kBufferPointer + kBufferSize - 1 },
+  { 0, 2, 1, kBufferPointer + 2 },
+  { 0, 4, 2, kBufferPointer + 8 },
+  { 0, 4, 9, kBufferPointer + 36 },
+  { kBufferSize - 1, 1, 0, kBufferPointer + kBufferSize - 1 },
+  // Invalid array elemenets
+  { 0, 1, kBufferSize, NULL },
+  { 0, 4, 10, NULL },
+  { kBufferSize - 1, 1, 1, NULL },
+  { kBufferSize - 1, 2, 0, NULL },
+  { kBufferSize, 1, 0, NULL },
+};
+const size_t kNumElements = sizeof(kElements) / sizeof(kElements[0]);
+
+}  // namespace
+
+TEST(MemoryRangeTest, DefaultConstructor) {
+  MemoryRange range;
+  EXPECT_EQ(NULL, range.data());
+  EXPECT_EQ(0, range.length());
+}
+
+TEST(MemoryRangeTest, ConstructorWithDataAndLength) {
+  MemoryRange range(kBuffer, kBufferSize);
+  EXPECT_EQ(kBufferPointer, range.data());
+  EXPECT_EQ(kBufferSize, range.length());
+}
+
+TEST(MemoryRangeTest, Reset) {
+  MemoryRange range;
+  range.Reset();
+  EXPECT_EQ(NULL, range.data());
+  EXPECT_EQ(0, range.length());
+
+  range.Set(kBuffer, kBufferSize);
+  EXPECT_EQ(kBufferPointer, range.data());
+  EXPECT_EQ(kBufferSize, range.length());
+
+  range.Reset();
+  EXPECT_EQ(NULL, range.data());
+  EXPECT_EQ(0, range.length());
+}
+
+TEST(MemoryRangeTest, Set) {
+  MemoryRange range;
+  range.Set(kBuffer, kBufferSize);
+  EXPECT_EQ(kBufferPointer, range.data());
+  EXPECT_EQ(kBufferSize, range.length());
+
+  range.Set(NULL, 0);
+  EXPECT_EQ(NULL, range.data());
+  EXPECT_EQ(0, range.length());
+}
+
+TEST(MemoryRangeTest, SubrangeOfEmptyMemoryRange) {
+  MemoryRange range;
+  MemoryRange subrange = range.Subrange(0, 10);
+  EXPECT_EQ(NULL, subrange.data());
+  EXPECT_EQ(0, subrange.length());
+}
+
+TEST(MemoryRangeTest, SubrangeAndGetData) {
+  MemoryRange range(kBuffer, kBufferSize);
+  for (size_t i = 0; i < kNumSubranges; ++i) {
+    bool valid = kSubranges[i].valid;
+    size_t sub_offset = kSubranges[i].offset;
+    size_t sub_length = kSubranges[i].length;
+    SCOPED_TRACE(Message() << "offset=" << sub_offset
+                 << ", length=" << sub_length);
+
+    MemoryRange subrange = range.Subrange(sub_offset, sub_length);
+    if (valid) {
+      EXPECT_TRUE(range.Covers(sub_offset, sub_length));
+      EXPECT_EQ(kBufferPointer + sub_offset,
+                range.GetData(sub_offset, sub_length));
+      EXPECT_EQ(kBufferPointer + sub_offset, subrange.data());
+      EXPECT_EQ(sub_length, subrange.length());
+    } else {
+      EXPECT_FALSE(range.Covers(sub_offset, sub_length));
+      EXPECT_EQ(NULL, range.GetData(sub_offset, sub_length));
+      EXPECT_EQ(NULL, subrange.data());
+      EXPECT_EQ(0, subrange.length());
+    }
+  }
+}
+
+TEST(MemoryRangeTest, GetDataWithTemplateType) {
+  MemoryRange range(kBuffer, kBufferSize);
+  const char* char_pointer = range.GetData<char>(0);
+  EXPECT_EQ(reinterpret_cast<const char*>(kBufferPointer), char_pointer);
+  const int* int_pointer = range.GetData<int>(0);
+  EXPECT_EQ(reinterpret_cast<const int*>(kBufferPointer), int_pointer);
+}
+
+TEST(MemoryRangeTest, GetArrayElement) {
+  MemoryRange range(kBuffer, kBufferSize);
+  for (size_t i = 0; i < kNumElements; ++i) {
+    size_t element_offset = kElements[i].offset;
+    size_t element_size = kElements[i].size;
+    unsigned element_index = kElements[i].index;
+    const void* const element_pointer = kElements[i].pointer;
+    SCOPED_TRACE(Message() << "offset=" << element_offset
+                 << ", size=" << element_size
+                 << ", index=" << element_index);
+    EXPECT_EQ(element_pointer, range.GetArrayElement(
+        element_offset, element_size, element_index));
+  }
+}
+
+TEST(MemoryRangeTest, GetArrayElmentWithTemplateType) {
+  MemoryRange range(kBuffer, kBufferSize);
+  const char* char_pointer = range.GetArrayElement<char>(0, 0);
+  EXPECT_EQ(reinterpret_cast<const char*>(kBufferPointer), char_pointer);
+  const int* int_pointer = range.GetArrayElement<int>(0, 0);
+  EXPECT_EQ(reinterpret_cast<const int*>(kBufferPointer), int_pointer);
+}