[Courgette] Make ELF section header sorting less intrusive.

courgette/disassembler_elf_32_x86_unittest.cc

 // 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.
 
 #include "courgette/disassembler_elf_32_x86.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "courgette/assembly_program.h"
 #include "courgette/base_test_unittest.h"
 #include "courgette/image_utils.h"
 
 namespace courgette {
 
 namespace {
 
+class TestDisassemblerElf32X86 : public DisassemblerElf32X86 {
+ public:
+  TestDisassemblerElf32X86(const void* start, size_t length)
+    : DisassemblerElf32X86(start, length) { }
+  ~TestDisassemblerElf32X86() override { }
+
+  void TestSectionHeaderFileOffsetOrder() {
+    std::vector<FileOffset> file_offsets;
+    for (Elf32_Half section_id : section_header_file_offset_order_) {
+      const Elf32_Shdr* section_header = SectionHeader(section_id);
+      file_offsets.push_back(section_header->sh_offset);
+    }
+    EXPECT_EQ(static_cast<size_t>(SectionHeaderCount()), file_offsets.size());

[Will Harris, 2016/04/19 18:36:35]

brackets in wrong place?

[huangs, 2016/04/19 19:02:53]

I looked carefully, looks alright.  static_cast<>() makes it look weird.

[Will Harris, 2016/04/19 19:44:25]

ah yes you're right I was missing the close bracket.

[huangs, 2016/04/19 19:59:52]

Acknowledged.

+    EXPECT_TRUE(std::is_sorted(file_offsets.begin(), file_offsets.end()));
+  }
+};
+
 class DisassemblerElf32X86Test : public BaseTest {
  public:
   void TestExe(const char* file_name,
                size_t expected_abs_count,
                size_t expected_rel_count) const;
 };
 
 void DisassemblerElf32X86Test::TestExe(const char* file_name,
                                        size_t expected_abs_count,
                                        size_t expected_rel_count) const {
   using TypedRVA = DisassemblerElf32::TypedRVA;
   std::string file1 = FileContents(file_name);
 
-  std::unique_ptr<DisassemblerElf32X86> disassembler(
-      new DisassemblerElf32X86(file1.c_str(), file1.length()));
+  std::unique_ptr<TestDisassemblerElf32X86> disassembler(
+      new TestDisassemblerElf32X86(file1.c_str(), file1.length()));
 
   bool can_parse_header = disassembler->ParseHeader();
   EXPECT_TRUE(can_parse_header);
   EXPECT_TRUE(disassembler->ok());
 
   // The length of the disassembled value will be slightly smaller than the
   // real file, since trailing debug info is not included
   EXPECT_EQ(file1.length(), disassembler->length());
 
   const uint8_t* offset_p = disassembler->FileOffsetToPointer(0);
@@ skipping 30 matching lines @@
   while (abs32_it != abs32_list.end() && rel32_it != rel32_list.end()) {
     if (*abs32_it < *rel32_it) {
       ++abs32_it;
     } else if (*abs32_it > *rel32_it) {
       ++rel32_it;
     } else {
       found_match = true;
     }
   }
   EXPECT_FALSE(found_match);
+
+  disassembler->TestSectionHeaderFileOffsetOrder();
 }
 
 }  // namespace
 
 TEST_F(DisassemblerElf32X86Test, All) {
   TestExe("elf-32-1", 200, 3441);
+  TestExe("elf-32-high-bss", 0, 13);
 }
 
 }  // namespace courgette