Split elf_writer_debug.cc to several files.

Refactoring only. The file has grown significantly over time,
and it is time to split it so it can be better managed.

Change-Id: Idce0231718add722292f4701df353d5baf31de5f
diff --git a/compiler/debug/elf_debug_writer.cc b/compiler/debug/elf_debug_writer.cc
new file mode 100644
index 0000000..01bd679
--- /dev/null
+++ b/compiler/debug/elf_debug_writer.cc
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#include "elf_debug_writer.h"
+
+#include <vector>
+
+#include "debug/dwarf/dwarf_constants.h"
+#include "debug/elf_compilation_unit.h"
+#include "debug/elf_debug_frame_writer.h"
+#include "debug/elf_debug_info_writer.h"
+#include "debug/elf_debug_line_writer.h"
+#include "debug/elf_debug_loc_writer.h"
+#include "debug/elf_gnu_debugdata_writer.h"
+#include "debug/elf_symtab_writer.h"
+#include "debug/method_debug_info.h"
+#include "elf_builder.h"
+#include "linker/vector_output_stream.h"
+#include "utils/array_ref.h"
+
+namespace art {
+namespace debug {
+
+template <typename ElfTypes>
+void WriteDebugInfo(ElfBuilder<ElfTypes>* builder,
+                    const ArrayRef<const MethodDebugInfo>& method_infos,
+                    dwarf::CFIFormat cfi_format,
+                    bool write_oat_patches) {
+  // Add methods to .symtab.
+  WriteDebugSymbols(builder, method_infos, true /* with_signature */);
+  // Generate CFI (stack unwinding information).
+  WriteCFISection(builder, method_infos, cfi_format, write_oat_patches);
+  // Write DWARF .debug_* sections.
+  WriteDebugSections(builder, method_infos, write_oat_patches);
+}
+
+template<typename ElfTypes>
+static void WriteDebugSections(ElfBuilder<ElfTypes>* builder,
+                               const ArrayRef<const MethodDebugInfo>& method_infos,
+                               bool write_oat_patches) {
+  // Group the methods into compilation units based on source file.
+  std::vector<ElfCompilationUnit> compilation_units;
+  const char* last_source_file = nullptr;
+  for (const MethodDebugInfo& mi : method_infos) {
+    auto& dex_class_def = mi.dex_file->GetClassDef(mi.class_def_index);
+    const char* source_file = mi.dex_file->GetSourceFile(dex_class_def);
+    if (compilation_units.empty() || source_file != last_source_file) {
+      compilation_units.push_back(ElfCompilationUnit());
+    }
+    ElfCompilationUnit& cu = compilation_units.back();
+    cu.methods.push_back(&mi);
+    cu.low_pc = std::min(cu.low_pc, mi.low_pc);
+    cu.high_pc = std::max(cu.high_pc, mi.high_pc);
+    last_source_file = source_file;
+  }
+
+  // Write .debug_line section.
+  if (!compilation_units.empty()) {
+    ElfDebugLineWriter<ElfTypes> line_writer(builder);
+    line_writer.Start();
+    for (auto& compilation_unit : compilation_units) {
+      line_writer.WriteCompilationUnit(compilation_unit);
+    }
+    line_writer.End(write_oat_patches);
+  }
+
+  // Write .debug_info section.
+  if (!compilation_units.empty()) {
+    ElfDebugInfoWriter<ElfTypes> info_writer(builder);
+    info_writer.Start();
+    for (const auto& compilation_unit : compilation_units) {
+      ElfCompilationUnitWriter<ElfTypes> cu_writer(&info_writer);
+      cu_writer.Write(compilation_unit);
+    }
+    info_writer.End(write_oat_patches);
+  }
+}
+
+std::vector<uint8_t> MakeMiniDebugInfo(
+    InstructionSet isa,
+    size_t rodata_size,
+    size_t text_size,
+    const ArrayRef<const MethodDebugInfo>& method_infos) {
+  if (Is64BitInstructionSet(isa)) {
+    return MakeMiniDebugInfoInternal<ElfTypes64>(isa, rodata_size, text_size, method_infos);
+  } else {
+    return MakeMiniDebugInfoInternal<ElfTypes32>(isa, rodata_size, text_size, method_infos);
+  }
+}
+
+template <typename ElfTypes>
+static ArrayRef<const uint8_t> WriteDebugElfFileForMethodInternal(
+    const MethodDebugInfo& method_info) {
+  const InstructionSet isa = method_info.compiled_method->GetInstructionSet();
+  std::vector<uint8_t> buffer;
+  buffer.reserve(KB);
+  VectorOutputStream out("Debug ELF file", &buffer);
+  std::unique_ptr<ElfBuilder<ElfTypes>> builder(new ElfBuilder<ElfTypes>(isa, &out));
+  // No program headers since the ELF file is not linked and has no allocated sections.
+  builder->Start(false /* write_program_headers */);
+  WriteDebugInfo(builder.get(),
+                 ArrayRef<const MethodDebugInfo>(&method_info, 1),
+                 dwarf::DW_DEBUG_FRAME_FORMAT,
+                 false /* write_oat_patches */);
+  builder->End();
+  CHECK(builder->Good());
+  // Make a copy of the buffer.  We want to shrink it anyway.
+  uint8_t* result = new uint8_t[buffer.size()];
+  CHECK(result != nullptr);
+  memcpy(result, buffer.data(), buffer.size());
+  return ArrayRef<const uint8_t>(result, buffer.size());
+}
+
+ArrayRef<const uint8_t> WriteDebugElfFileForMethod(const MethodDebugInfo& method_info) {
+  const InstructionSet isa = method_info.compiled_method->GetInstructionSet();
+  if (Is64BitInstructionSet(isa)) {
+    return WriteDebugElfFileForMethodInternal<ElfTypes64>(method_info);
+  } else {
+    return WriteDebugElfFileForMethodInternal<ElfTypes32>(method_info);
+  }
+}
+
+template <typename ElfTypes>
+static ArrayRef<const uint8_t> WriteDebugElfFileForClassesInternal(
+    const InstructionSet isa, const ArrayRef<mirror::Class*>& types)
+    SHARED_REQUIRES(Locks::mutator_lock_) {
+  std::vector<uint8_t> buffer;
+  buffer.reserve(KB);
+  VectorOutputStream out("Debug ELF file", &buffer);
+  std::unique_ptr<ElfBuilder<ElfTypes>> builder(new ElfBuilder<ElfTypes>(isa, &out));
+  // No program headers since the ELF file is not linked and has no allocated sections.
+  builder->Start(false /* write_program_headers */);
+  ElfDebugInfoWriter<ElfTypes> info_writer(builder.get());
+  info_writer.Start();
+  ElfCompilationUnitWriter<ElfTypes> cu_writer(&info_writer);
+  cu_writer.Write(types);
+  info_writer.End(false /* write_oat_patches */);
+
+  builder->End();
+  CHECK(builder->Good());
+  // Make a copy of the buffer.  We want to shrink it anyway.
+  uint8_t* result = new uint8_t[buffer.size()];
+  CHECK(result != nullptr);
+  memcpy(result, buffer.data(), buffer.size());
+  return ArrayRef<const uint8_t>(result, buffer.size());
+}
+
+ArrayRef<const uint8_t> WriteDebugElfFileForClasses(const InstructionSet isa,
+                                                    const ArrayRef<mirror::Class*>& types) {
+  if (Is64BitInstructionSet(isa)) {
+    return WriteDebugElfFileForClassesInternal<ElfTypes64>(isa, types);
+  } else {
+    return WriteDebugElfFileForClassesInternal<ElfTypes32>(isa, types);
+  }
+}
+
+// Explicit instantiations
+template void WriteDebugInfo<ElfTypes32>(
+    ElfBuilder<ElfTypes32>* builder,
+    const ArrayRef<const MethodDebugInfo>& method_infos,
+    dwarf::CFIFormat cfi_format,
+    bool write_oat_patches);
+template void WriteDebugInfo<ElfTypes64>(
+    ElfBuilder<ElfTypes64>* builder,
+    const ArrayRef<const MethodDebugInfo>& method_infos,
+    dwarf::CFIFormat cfi_format,
+    bool write_oat_patches);
+
+}  // namespace debug
+}  // namespace art