Report DWARF debug information for JITed code.

Change-Id: Ia5b2133c54386932c76c22774cf3d2ae61e0925f

9 files changed, 184 insertions, 23 deletions

diff --git a/compiler/dwarf/method_debug_info.h b/compiler/dwarf/method_debug_info.h
index a391e4d08a..e8ba9148e8 100644
--- a/compiler/dwarf/method_debug_info.h
+++ b/compiler/dwarf/method_debug_info.h
@@ -30,8 +30,8 @@ struct MethodDebugInfo {
   uint32_t access_flags_;
   const DexFile::CodeItem* code_item_;
   bool deduped_;
-  uint32_t low_pc_;
-  uint32_t high_pc_;
+  uintptr_t low_pc_;
+  uintptr_t high_pc_;
   CompiledMethod* compiled_method_;
 };
 
diff --git a/compiler/elf_builder.h b/compiler/elf_builder.h
index bb07cc2913..a7461a5525 100644
--- a/compiler/elf_builder.h
+++ b/compiler/elf_builder.h
@@ -148,6 +148,12 @@ class ElfBuilder FINAL {
       }
     }
 
+    // Returns true if the section was written to disk.
+    // (Used to check whether we have .text when writing JIT debug info)
+    bool Exists() const {
+      return finished_;
+    }
+
     // Get the location of this section in virtual memory.
     Elf_Addr GetAddress() const {
       CHECK(started_);
@@ -247,16 +253,18 @@ class ElfBuilder FINAL {
     }
 
     // Buffer symbol for this section.  It will be written later.
+    // If the symbol's section is null, it will be considered absolute (SHN_ABS).
+    // (we use this in JIT to reference code which is stored outside the debug ELF file)
     void Add(Elf_Word name, const Section* section,
              Elf_Addr addr, bool is_relative, Elf_Word size,
              uint8_t binding, uint8_t type, uint8_t other = 0) {
-      CHECK(section != nullptr);
       Elf_Sym sym = Elf_Sym();
       sym.st_name = name;
       sym.st_value = addr + (is_relative ? section->GetAddress() : 0);
       sym.st_size = size;
       sym.st_other = other;
-      sym.st_shndx = section->GetSectionIndex();
+      sym.st_shndx = (section != nullptr ? section->GetSectionIndex()
+                                         : static_cast<Elf_Word>(SHN_ABS));
       sym.st_info = (binding << 4) + (type & 0xf);
       symbols_.push_back(sym);
     }
diff --git a/compiler/elf_writer_debug.cc b/compiler/elf_writer_debug.cc
index 2bc8c89f73..315a8334b1 100644
--- a/compiler/elf_writer_debug.cc
+++ b/compiler/elf_writer_debug.cc
@@ -22,16 +22,17 @@
 #include "base/casts.h"
 #include "base/stl_util.h"
 #include "compiled_method.h"
-#include "driver/compiler_driver.h"
 #include "dex_file-inl.h"
+#include "driver/compiler_driver.h"
 #include "dwarf/dedup_vector.h"
 #include "dwarf/headers.h"
 #include "dwarf/method_debug_info.h"
 #include "dwarf/register.h"
 #include "elf_builder.h"
+#include "linker/vector_output_stream.h"
 #include "oat_writer.h"
-#include "utils.h"
 #include "stack_map.h"
+#include "utils.h"
 
 namespace art {
 namespace dwarf {
@@ -234,7 +235,9 @@ void WriteCFISection(ElfBuilder<ElfTypes>* builder,
   {
     cfi_section->Start();
     const bool is64bit = Is64BitInstructionSet(builder->GetIsa());
-    const Elf_Addr text_address = builder->GetText()->GetAddress();
+    const Elf_Addr text_address = builder->GetText()->Exists()
+        ? builder->GetText()->GetAddress()
+        : 0;
     const Elf_Addr cfi_address = cfi_section->GetAddress();
     const Elf_Addr cie_address = cfi_address;
     Elf_Addr buffer_address = cfi_address;
@@ -305,8 +308,8 @@ namespace {
   struct CompilationUnit {
     std::vector<const MethodDebugInfo*> methods_;
     size_t debug_line_offset_ = 0;
-    uint32_t low_pc_ = 0xFFFFFFFFU;
-    uint32_t high_pc_ = 0;
+    uintptr_t low_pc_ = std::numeric_limits<uintptr_t>::max();
+    uintptr_t high_pc_ = 0;
   };
 
   typedef std::vector<DexFile::LocalInfo> LocalInfos;
@@ -439,14 +442,17 @@ class DebugInfoWriter {
 
     void Write(const CompilationUnit& compilation_unit) {
       CHECK(!compilation_unit.methods_.empty());
-      const Elf_Addr text_address = owner_->builder_->GetText()->GetAddress();
+      const Elf_Addr text_address = owner_->builder_->GetText()->Exists()
+          ? owner_->builder_->GetText()->GetAddress()
+          : 0;
+      const uintptr_t cu_size = compilation_unit.high_pc_ - compilation_unit.low_pc_;
 
       info_.StartTag(DW_TAG_compile_unit);
       info_.WriteStrp(DW_AT_producer, owner_->WriteString("Android dex2oat"));
       info_.WriteData1(DW_AT_language, DW_LANG_Java);
       info_.WriteStrp(DW_AT_comp_dir, owner_->WriteString("$JAVA_SRC_ROOT"));
       info_.WriteAddr(DW_AT_low_pc, text_address + compilation_unit.low_pc_);
-      info_.WriteUdata(DW_AT_high_pc, compilation_unit.high_pc_ - compilation_unit.low_pc_);
+      info_.WriteUdata(DW_AT_high_pc, dchecked_integral_cast<uint32_t>(cu_size));
       info_.WriteSecOffset(DW_AT_stmt_list, compilation_unit.debug_line_offset_);
 
       const char* last_dex_class_desc = nullptr;
@@ -476,7 +482,7 @@ class DebugInfoWriter {
         info_.StartTag(DW_TAG_subprogram);
         WriteName(dex->GetMethodName(dex_method));
         info_.WriteAddr(DW_AT_low_pc, text_address + mi->low_pc_);
-        info_.WriteUdata(DW_AT_high_pc, mi->high_pc_ - mi->low_pc_);
+        info_.WriteUdata(DW_AT_high_pc, dchecked_integral_cast<uint32_t>(mi->high_pc_-mi->low_pc_));
         uint8_t frame_base[] = { DW_OP_call_frame_cfa };
         info_.WriteExprLoc(DW_AT_frame_base, &frame_base, sizeof(frame_base));
         WriteLazyType(dex->GetReturnTypeDescriptor(dex_proto));
@@ -924,7 +930,9 @@ class DebugLineWriter {
   // Returns the number of bytes written.
   size_t WriteCompilationUnit(CompilationUnit& compilation_unit) {
     const bool is64bit = Is64BitInstructionSet(builder_->GetIsa());
-    const Elf_Addr text_address = builder_->GetText()->GetAddress();
+    const Elf_Addr text_address = builder_->GetText()->Exists()
+        ? builder_->GetText()->GetAddress()
+        : 0;
 
     compilation_unit.debug_line_offset_ = builder_->GetDebugLine()->GetSize();
 
@@ -1173,11 +1181,13 @@ void WriteDebugSymbols(ElfBuilder<ElfTypes>* builder,
       name += " [DEDUPED]";
     }
 
+    const auto* text = builder->GetText()->Exists() ? builder->GetText() : nullptr;
+    const bool is_relative = (text != nullptr);
     uint32_t low_pc = info.low_pc_;
     // Add in code delta, e.g., thumb bit 0 for Thumb2 code.
     low_pc += info.compiled_method_->CodeDelta();
-    symtab->Add(strtab->Write(name), builder->GetText(), low_pc,
-                true, info.high_pc_ - info.low_pc_, STB_GLOBAL, STT_FUNC);
+    symtab->Add(strtab->Write(name), text, low_pc,
+                is_relative, info.high_pc_ - info.low_pc_, STB_GLOBAL, STT_FUNC);
 
     // Conforming to aaelf, add $t mapping symbol to indicate start of a sequence of thumb2
     // instructions, so that disassembler tools can correctly disassemble.
@@ -1185,8 +1195,8 @@ void WriteDebugSymbols(ElfBuilder<ElfTypes>* builder,
     // requires it to match function symbol.  Just address 0 does not work.
     if (info.compiled_method_->GetInstructionSet() == kThumb2) {
       if (!generated_mapping_symbol || !kGenerateSingleArmMappingSymbol) {
-        symtab->Add(strtab->Write("$t"), builder->GetText(), info.low_pc_ & ~1,
-                    true, 0, STB_LOCAL, STT_NOTYPE);
+        symtab->Add(strtab->Write("$t"), text, info.low_pc_ & ~1,
+                    is_relative, 0, STB_LOCAL, STT_NOTYPE);
         generated_mapping_symbol = true;
       }
     }
@@ -1214,6 +1224,36 @@ void WriteDebugInfo(ElfBuilder<ElfTypes>* builder,
   }
 }
 
+template <typename ElfTypes>
+static ArrayRef<const uint8_t> WriteDebugElfFileInternal(
+    const dwarf::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));
+  builder->Start();
+  WriteDebugInfo(builder.get(),
+                 ArrayRef<const MethodDebugInfo>(&method_info, 1),
+                 DW_DEBUG_FRAME_FORMAT);
+  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> WriteDebugElfFile(const dwarf::MethodDebugInfo& method_info) {
+  const InstructionSet isa = method_info.compiled_method_->GetInstructionSet();
+  if (Is64BitInstructionSet(isa)) {
+    return WriteDebugElfFileInternal<ElfTypes64>(method_info);
+  } else {
+    return WriteDebugElfFileInternal<ElfTypes32>(method_info);
+  }
+}
+
 // Explicit instantiations
 template void WriteDebugInfo<ElfTypes32>(
     ElfBuilder<ElfTypes32>* builder,
diff --git a/compiler/elf_writer_debug.h b/compiler/elf_writer_debug.h
index 7ec0be185a..94e09d7ccf 100644
--- a/compiler/elf_writer_debug.h
+++ b/compiler/elf_writer_debug.h
@@ -30,6 +30,8 @@ void WriteDebugInfo(ElfBuilder<ElfTypes>* builder,
                     const ArrayRef<const MethodDebugInfo>& method_infos,
                     CFIFormat cfi_format);
 
+ArrayRef<const uint8_t> WriteDebugElfFile(const dwarf::MethodDebugInfo& method_info);
+
 }  // namespace dwarf
 }  // namespace art
 
diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index 3eb72744ee..82f1e84454 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -17,6 +17,7 @@
 #include "optimizing_compiler.h"
 
 #include <fstream>
+#include <memory>
 #include <stdint.h>
 
 #ifdef ART_ENABLE_CODEGEN_arm64
@@ -52,6 +53,8 @@
 #include "driver/compiler_driver-inl.h"
 #include "driver/compiler_options.h"
 #include "driver/dex_compilation_unit.h"
+#include "dwarf/method_debug_info.h"
+#include "elf_writer_debug.h"
 #include "elf_writer_quick.h"
 #include "graph_checker.h"
 #include "graph_visualizer.h"
@@ -60,6 +63,7 @@
 #include "inliner.h"
 #include "instruction_simplifier.h"
 #include "intrinsics.h"
+#include "jit/debugger_interface.h"
 #include "jit/jit_code_cache.h"
 #include "licm.h"
 #include "jni/quick/jni_compiler.h"
@@ -68,6 +72,7 @@
 #include "prepare_for_register_allocation.h"
 #include "reference_type_propagation.h"
 #include "register_allocator.h"
+#include "oat_quick_method_header.h"
 #include "sharpening.h"
 #include "side_effects_analysis.h"
 #include "ssa_builder.h"
@@ -968,6 +973,39 @@ bool OptimizingCompiler::JitCompile(Thread* self,
     return false;
   }
 
+  if (GetCompilerDriver()->GetCompilerOptions().GetGenerateDebugInfo()) {
+    const auto* method_header = reinterpret_cast<const OatQuickMethodHeader*>(code);
+    const uintptr_t code_address = reinterpret_cast<uintptr_t>(method_header->GetCode());
+    CompiledMethod compiled_method(
+        GetCompilerDriver(),
+        codegen->GetInstructionSet(),
+        ArrayRef<const uint8_t>(code_allocator.GetMemory()),
+        codegen->HasEmptyFrame() ? 0 : codegen->GetFrameSize(),
+        codegen->GetCoreSpillMask(),
+        codegen->GetFpuSpillMask(),
+        ArrayRef<const SrcMapElem>(),
+        ArrayRef<const uint8_t>(),  // mapping_table.
+        ArrayRef<const uint8_t>(stack_map_data, stack_map_size),
+        ArrayRef<const uint8_t>(),  // native_gc_map.
+        ArrayRef<const uint8_t>(*codegen->GetAssembler()->cfi().data()),
+        ArrayRef<const LinkerPatch>());
+    dwarf::MethodDebugInfo method_debug_info {
+        dex_file,
+        class_def_idx,
+        method_idx,
+        access_flags,
+        code_item,
+        false,  // deduped.
+        code_address,
+        code_address + code_allocator.GetSize(),
+        &compiled_method
+    };
+    ArrayRef<const uint8_t> elf_file = dwarf::WriteDebugElfFile(method_debug_info);
+    CreateJITCodeEntryForAddress(code_address,
+                                 std::unique_ptr<const uint8_t[]>(elf_file.data()),
+                                 elf_file.size());
+  }
+
   return true;
 }
 
diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index 263f50de51..f674a6f3c8 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -75,6 +75,7 @@ enum LockLevel {
   kReferenceQueueWeakReferencesLock,
   kReferenceQueueClearedReferencesLock,
   kReferenceProcessorLock,
+  kJitDebugInterfaceLock,
   kJitCodeCacheLock,
   kAllocSpaceLock,
   kBumpPointerSpaceBlockLock,
diff --git a/runtime/jit/debugger_interface.cc b/runtime/jit/debugger_interface.cc
index 3c2898b8ac..f08a1a9d90 100644
--- a/runtime/jit/debugger_interface.cc
+++ b/runtime/jit/debugger_interface.cc
@@ -16,6 +16,13 @@
 
 #include "debugger_interface.h"
 
+#include "base/logging.h"
+#include "base/mutex.h"
+#include "thread-inl.h"
+#include "thread.h"
+
+#include <unordered_map>
+
 namespace art {
 
 // -------------------------------------------------------------------
@@ -57,13 +64,19 @@ extern "C" {
   JITDescriptor __jit_debug_descriptor = { 1, JIT_NOACTION, nullptr, nullptr };
 }
 
-JITCodeEntry* CreateJITCodeEntry(const uint8_t *symfile_addr, uintptr_t symfile_size) {
+static Mutex g_jit_debug_mutex("JIT debug interface lock", kJitDebugInterfaceLock);
+
+static JITCodeEntry* CreateJITCodeEntryInternal(
+    std::unique_ptr<const uint8_t[]> symfile_addr,
+    uintptr_t symfile_size)
+    REQUIRES(g_jit_debug_mutex) {
+  DCHECK(symfile_addr.get() != nullptr);
+
   JITCodeEntry* entry = new JITCodeEntry;
-  entry->symfile_addr_ = symfile_addr;
+  entry->symfile_addr_ = symfile_addr.release();
   entry->symfile_size_ = symfile_size;
   entry->prev_ = nullptr;
 
-  // TODO: Do we need a lock here?
   entry->next_ = __jit_debug_descriptor.first_entry_;
   if (entry->next_ != nullptr) {
     entry->next_->prev_ = entry;
@@ -76,8 +89,7 @@ JITCodeEntry* CreateJITCodeEntry(const uint8_t *symfile_addr, uintptr_t symfile_
   return entry;
 }
 
-void DeleteJITCodeEntry(JITCodeEntry* entry) {
-  // TODO: Do we need a lock here?
+static void DeleteJITCodeEntryInternal(JITCodeEntry* entry) REQUIRES(g_jit_debug_mutex) {
   if (entry->prev_ != nullptr) {
     entry->prev_->next_ = entry->next_;
   } else {
@@ -91,7 +103,48 @@ void DeleteJITCodeEntry(JITCodeEntry* entry) {
   __jit_debug_descriptor.relevant_entry_ = entry;
   __jit_debug_descriptor.action_flag_ = JIT_UNREGISTER_FN;
   __jit_debug_register_code();
+  delete[] entry->symfile_addr_;
   delete entry;
 }
 
+JITCodeEntry* CreateJITCodeEntry(std::unique_ptr<const uint8_t[]> symfile_addr,
+                                 uintptr_t symfile_size) {
+  Thread* self = Thread::Current();
+  MutexLock mu(self, g_jit_debug_mutex);
+  return CreateJITCodeEntryInternal(std::move(symfile_addr), symfile_size);
+}
+
+void DeleteJITCodeEntry(JITCodeEntry* entry) {
+  Thread* self = Thread::Current();
+  MutexLock mu(self, g_jit_debug_mutex);
+  DeleteJITCodeEntryInternal(entry);
+}
+
+// Mapping from address to entry.  It takes ownership of the entries
+// so that the user of the JIT interface does not have to store them.
+static std::unordered_map<uintptr_t, JITCodeEntry*> g_jit_code_entries;
+
+void CreateJITCodeEntryForAddress(uintptr_t address,
+                                  std::unique_ptr<const uint8_t[]> symfile_addr,
+                                  uintptr_t symfile_size) {
+  Thread* self = Thread::Current();
+  MutexLock mu(self, g_jit_debug_mutex);
+  DCHECK_NE(address, 0u);
+  DCHECK(g_jit_code_entries.find(address) == g_jit_code_entries.end());
+  JITCodeEntry* entry = CreateJITCodeEntryInternal(std::move(symfile_addr), symfile_size);
+  g_jit_code_entries.emplace(address, entry);
+}
+
+bool DeleteJITCodeEntryForAddress(uintptr_t address) {
+  Thread* self = Thread::Current();
+  MutexLock mu(self, g_jit_debug_mutex);
+  const auto& it = g_jit_code_entries.find(address);
+  if (it == g_jit_code_entries.end()) {
+    return false;
+  }
+  DeleteJITCodeEntryInternal(it->second);
+  g_jit_code_entries.erase(it);
+  return true;
+}
+
 }  // namespace art
diff --git a/runtime/jit/debugger_interface.h b/runtime/jit/debugger_interface.h
index a784ef5990..74469a98d0 100644
--- a/runtime/jit/debugger_interface.h
+++ b/runtime/jit/debugger_interface.h
@@ -18,6 +18,7 @@
 #define ART_RUNTIME_JIT_DEBUGGER_INTERFACE_H_
 
 #include <inttypes.h>
+#include <memory>
 
 namespace art {
 
@@ -26,11 +27,25 @@ extern "C" {
 }
 
 // Notify native debugger about new JITed code by passing in-memory ELF.
-JITCodeEntry* CreateJITCodeEntry(const uint8_t *symfile_addr, uintptr_t symfile_size);
+// It takes ownership of the in-memory ELF file.
+JITCodeEntry* CreateJITCodeEntry(std::unique_ptr<const uint8_t[]> symfile_addr,
+                                 uintptr_t symfile_size);
 
 // Notify native debugger that JITed code has been removed.
+// It also releases the associated in-memory ELF file.
 void DeleteJITCodeEntry(JITCodeEntry* entry);
 
+// Notify native debugger about new JITed code by passing in-memory ELF.
+// The address is used only to uniquely identify the entry.
+// It takes ownership of the in-memory ELF file.
+void CreateJITCodeEntryForAddress(uintptr_t address,
+                                  std::unique_ptr<const uint8_t[]> symfile_addr,
+                                  uintptr_t symfile_size);
+
+// Notify native debugger that JITed code has been removed.
+// Returns false if entry for the given address was not found.
+bool DeleteJITCodeEntryForAddress(uintptr_t address);
+
 }  // namespace art
 
 #endif  // ART_RUNTIME_JIT_DEBUGGER_INTERFACE_H_
diff --git a/runtime/jit/jit_code_cache.cc b/runtime/jit/jit_code_cache.cc
index c260ca4629..1ac57b1d84 100644
--- a/runtime/jit/jit_code_cache.cc
+++ b/runtime/jit/jit_code_cache.cc
@@ -21,6 +21,7 @@
 #include "art_method-inl.h"
 #include "base/stl_util.h"
 #include "base/time_utils.h"
+#include "debugger_interface.h"
 #include "entrypoints/runtime_asm_entrypoints.h"
 #include "gc/accounting/bitmap-inl.h"
 #include "jit/profiling_info.h"
@@ -215,6 +216,9 @@ void JitCodeCache::FreeCode(const void* code_ptr, ArtMethod* method ATTRIBUTE_UN
   uintptr_t allocation = FromCodeToAllocation(code_ptr);
   const OatQuickMethodHeader* method_header = OatQuickMethodHeader::FromCodePointer(code_ptr);
   const uint8_t* data = method_header->GetNativeGcMap();
+  // Notify native debugger that we are about to remove the code.
+  // It does nothing if we are not using native debugger.
+  DeleteJITCodeEntryForAddress(reinterpret_cast<uintptr_t>(code_ptr));
   if (data != nullptr) {
     mspace_free(data_mspace_, const_cast<uint8_t*>(data));
   }