text: /*
   * Copyright (c) Facebook, Inc. and its affiliates.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <folly/FileUtil.h>
  #include <folly/experimental/TestUtil.h>
  #include <folly/experimental/symbolizer/Elf.h>
  #include <folly/portability/GTest.h>
  
  using folly::symbolizer::ElfFile;
  
  // Add some symbols for testing. Note that we have to be careful with type
  // signatures here to prevent name mangling
  uint64_t kIntegerValue = 1234567890UL;
  const char* kStringValue = "coconuts";
  const char* const kDefaultElf = "/proc/self/exe";
  class ElfTest : public ::testing::Test {
   protected:
    ElfFile elfFile_{kDefaultElf};
  };
  
  TEST_F(ElfTest, IntegerValue) {
    auto sym = elfFile_.getSymbolByName("kIntegerValue");
    EXPECT_NE(nullptr, sym.first) << "Failed to look up symbol kIntegerValue";
    EXPECT_EQ(kIntegerValue, elfFile_.getSymbolValue<uint64_t>(sym.second));
  }
  
  TEST_F(ElfTest, PointerValue) {
    auto sym = elfFile_.getSymbolByName("kStringValue");
    EXPECT_NE(nullptr, sym.first) << "Failed to look up symbol kStringValue";
    ElfW(Addr) addr = elfFile_.getSymbolValue<ElfW(Addr)>(sym.second);
    const char* str = &elfFile_.getAddressValue<const char>(addr);
    EXPECT_STREQ(kStringValue, str);
  }
  
  TEST_F(ElfTest, iterateProgramHeaders) {
    auto phdr = elfFile_.iterateProgramHeaders(
        [](auto& h) { return h.p_type == PT_LOAD; });
    EXPECT_NE(nullptr, phdr);
    EXPECT_GE(phdr->p_filesz, 0);
  }
  
  TEST_F(ElfTest, TinyNonElfFile) {
    folly::test::TemporaryFile tmpFile;
    const static folly::StringPiece contents = "!";
    folly::writeFull(tmpFile.fd(), contents.data(), contents.size());
  
    ElfFile elfFile;
    auto res = elfFile.openNoThrow(tmpFile.path().c_str(), true);
    EXPECT_EQ(ElfFile::kInvalidElfFile, res.code);
    EXPECT_STREQ("not an ELF file (too short)", res.msg);
  }
  
  TEST_F(ElfTest, NonElfScript) {
    folly::test::TemporaryFile tmpFile;
    const static folly::StringPiece contents =
        "#!/bin/sh\necho I'm small non-ELF executable\n";
    folly::writeFull(tmpFile.fd(), contents.data(), contents.size());
  
    ElfFile elfFile;
    auto res = elfFile.openNoThrow(tmpFile.path().c_str(), true);
    EXPECT_EQ(ElfFile::kInvalidElfFile, res.code);
    EXPECT_STREQ("invalid ELF magic", res.msg);
  }
  
  TEST_F(ElfTest, FailToOpenLargeFilename) {
    // ElfFile used to segfault if it failed to open large filenames
    folly::test::TemporaryDirectory tmpDir;
    auto elfFile = std::make_unique<ElfFile>(); // on the heap so asan can see it
    auto const largeNonExistingName = (tmpDir.path() / std::string(1000, 'x'));
    ASSERT_EQ(
        ElfFile::kSystemError,
        elfFile->openNoThrow(largeNonExistingName.c_str()));
    ASSERT_EQ(
        ElfFile::kSystemError,
        elfFile->openNoThrow(largeNonExistingName.c_str()));
    EXPECT_EQ(ElfFile::kSuccess, elfFile->openNoThrow(kDefaultElf));
  }
  