Revert "Revert "Add small library for writing of DWARF data.""

Use objdump from prebuilts.

This reverts commit 1ded5beffa4bae6203e1fa03903c6ffa2766bf4c.

Change-Id: I91f61a91827406930039ccf8691359b1c2636640
diff --git a/compiler/dwarf/dwarf_test.h b/compiler/dwarf/dwarf_test.h
new file mode 100644
index 0000000..dd5e0c2
--- /dev/null
+++ b/compiler/dwarf/dwarf_test.h
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef ART_COMPILER_DWARF_DWARF_TEST_H_
+#define ART_COMPILER_DWARF_DWARF_TEST_H_
+
+#include <cstring>
+#include <dirent.h>
+#include <memory>
+#include <set>
+#include <stdio.h>
+#include <string>
+#include <sys/types.h>
+
+#include "utils.h"
+#include "base/unix_file/fd_file.h"
+#include "common_runtime_test.h"
+#include "elf_builder.h"
+#include "gtest/gtest.h"
+#include "os.h"
+
+namespace art {
+namespace dwarf {
+
+#define DW_CHECK(substring) Check(substring, false, __FILE__, __LINE__)
+#define DW_CHECK_NEXT(substring) Check(substring, true, __FILE__, __LINE__)
+
+class DwarfTest : public CommonRuntimeTest {
+ public:
+  static constexpr bool kPrintObjdumpOutput = false;  // debugging.
+
+  struct ExpectedLine {
+    std::string substring;
+    bool next;
+    const char* at_file;
+    int at_line;
+  };
+
+  // Check that the objdump output contains given output.
+  // If next is true, it must be the next line.  Otherwise lines are skipped.
+  void Check(const char* substr, bool next, const char* at_file, int at_line) {
+    expected_lines_.push_back(ExpectedLine {substr, next, at_file, at_line});
+  }
+
+  static std::string GetObjdumpPath() {
+    const char* android_build_top = getenv("ANDROID_BUILD_TOP");
+    if (android_build_top != nullptr) {
+      std::string host_prebuilts = std::string(android_build_top) +
+                                   "/prebuilts/gcc/linux-x86/host/";
+      // Read the content of the directory.
+      std::set<std::string> entries;
+      DIR* dir = opendir(host_prebuilts.c_str());
+      if (dir != nullptr) {
+        struct dirent* entry;
+        while ((entry = readdir(dir)) != nullptr) {
+          if (strstr(entry->d_name, "linux-glibc")) {
+            entries.insert(host_prebuilts + entry->d_name);
+          }
+        }
+        closedir(dir);
+      }
+      // Strings are sorted so the last one should be the most recent version.
+      if (!entries.empty()) {
+        std::string path = *entries.rbegin() + "/x86_64-linux/bin/objdump";
+        struct stat st;
+        if (stat(path.c_str(), &st) == 0) {
+          return path;  // File exists.
+        }
+      }
+    }
+    ADD_FAILURE() << "Can not find prebuild objdump.";
+    return "objdump";  // Use the system objdump as fallback.
+  }
+
+  // Pretty-print the generated DWARF data using objdump.
+  template<typename Elf_Word, typename Elf_Sword, typename Elf_Addr, typename Elf_Dyn,
+           typename Elf_Sym, typename Elf_Ehdr, typename Elf_Phdr, typename Elf_Shdr>
+  std::vector<std::string> Objdump(bool is64bit, const char* args) {
+    // Write simple elf file with just the DWARF sections.
+    class NoCode : public CodeOutput {
+      virtual void SetCodeOffset(size_t) { }
+      virtual bool Write(OutputStream*) { return true; }
+    } code;
+    ScratchFile file;
+    InstructionSet isa = is64bit ? kX86_64 : kX86;
+    ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
+               Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr> builder(
+        &code, file.GetFile(), isa, 0, 0, 0, 0, 0, 0, false, false);
+    typedef ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> Section;
+    if (!debug_info_data_.empty()) {
+      Section debug_info(".debug_info", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+      debug_info.SetBuffer(debug_info_data_);
+      builder.RegisterRawSection(debug_info);
+    }
+    if (!debug_abbrev_data_.empty()) {
+      Section debug_abbrev(".debug_abbrev", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+      debug_abbrev.SetBuffer(debug_abbrev_data_);
+      builder.RegisterRawSection(debug_abbrev);
+    }
+    if (!debug_str_data_.empty()) {
+      Section debug_str(".debug_str", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+      debug_str.SetBuffer(debug_str_data_);
+      builder.RegisterRawSection(debug_str);
+    }
+    if (!debug_line_data_.empty()) {
+      Section debug_line(".debug_line", SHT_PROGBITS, 0, nullptr, 0, 1, 0);
+      debug_line.SetBuffer(debug_line_data_);
+      builder.RegisterRawSection(debug_line);
+    }
+    if (!eh_frame_data_.empty()) {
+      Section eh_frame(".eh_frame", SHT_PROGBITS, SHF_ALLOC, nullptr, 0, 4, 0);
+      eh_frame.SetBuffer(eh_frame_data_);
+      builder.RegisterRawSection(eh_frame);
+    }
+    builder.Init();
+    builder.Write();
+
+    // Read the elf file back using objdump.
+    std::vector<std::string> lines;
+    std::string cmd = GetObjdumpPath();
+    cmd = cmd + " " + args + " " + file.GetFilename() + " 2>&1";
+    FILE* output = popen(cmd.data(), "r");
+    char buffer[1024];
+    const char* line;
+    while ((line = fgets(buffer, sizeof(buffer), output)) != nullptr) {
+      if (kPrintObjdumpOutput) {
+        printf("%s", line);
+      }
+      if (line[0] != '\0' && line[0] != '\n') {
+        EXPECT_TRUE(strstr(line, "objdump: Error:") == nullptr) << line;
+        EXPECT_TRUE(strstr(line, "objdump: Warning:") == nullptr) << line;
+        std::string str(line);
+        if (str.back() == '\n') {
+          str.pop_back();
+        }
+        lines.push_back(str);
+      }
+    }
+    pclose(output);
+    return lines;
+  }
+
+  std::vector<std::string> Objdump(bool is64bit, const char* args) {
+    if (is64bit) {
+      return Objdump<Elf64_Word, Elf64_Sword, Elf64_Addr, Elf64_Dyn,
+          Elf64_Sym, Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr>(is64bit, args);
+    } else {
+      return Objdump<Elf32_Word, Elf32_Sword, Elf32_Addr, Elf32_Dyn,
+          Elf32_Sym, Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr>(is64bit, args);
+    }
+  }
+
+  // Compare objdump output to the recorded checks.
+  void CheckObjdumpOutput(bool is64bit, const char* args) {
+    std::vector<std::string> actual_lines = Objdump(is64bit, args);
+    auto actual_line = actual_lines.begin();
+    for (const ExpectedLine& expected_line : expected_lines_) {
+      const std::string& substring = expected_line.substring;
+      if (actual_line == actual_lines.end()) {
+        ADD_FAILURE_AT(expected_line.at_file, expected_line.at_line) <<
+            "Expected '" << substring << "'.\n" <<
+            "Seen end of output.";
+      } else if (expected_line.next) {
+        if (actual_line->find(substring) == std::string::npos) {
+          ADD_FAILURE_AT(expected_line.at_file, expected_line.at_line) <<
+            "Expected '" << substring << "'.\n" <<
+            "Seen '" << actual_line->data() << "'.";
+        } else {
+          // printf("Found '%s' in '%s'.\n", substring.data(), actual_line->data());
+        }
+        actual_line++;
+      } else {
+        bool found = false;
+        for (auto it = actual_line; it < actual_lines.end(); it++) {
+          if (it->find(substring) != std::string::npos) {
+            actual_line = it;
+            found = true;
+            break;
+          }
+        }
+        if (!found) {
+          ADD_FAILURE_AT(expected_line.at_file, expected_line.at_line) <<
+            "Expected '" << substring << "'.\n" <<
+            "Not found anywhere in the rest of the output.";
+        } else {
+          // printf("Found '%s' in '%s'.\n", substring.data(), actual_line->data());
+          actual_line++;
+        }
+      }
+    }
+  }
+
+  // Buffers which are going to assembled into ELF file and passed to objdump.
+  std::vector<uint8_t> eh_frame_data_;
+  std::vector<uint8_t> debug_info_data_;
+  std::vector<uint8_t> debug_abbrev_data_;
+  std::vector<uint8_t> debug_str_data_;
+  std::vector<uint8_t> debug_line_data_;
+
+  // The expected output of objdump.
+  std::vector<ExpectedLine> expected_lines_;
+};
+
+}  // namespace dwarf
+}  // namespace art
+
+#endif  // ART_COMPILER_DWARF_DWARF_TEST_H_