| // Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include "vm/dwarf.h" |
| |
| #include "vm/code_comments.h" |
| #include "vm/code_descriptors.h" |
| #include "vm/elf.h" |
| #include "vm/image_snapshot.h" |
| #include "vm/object_store.h" |
| |
| namespace dart { |
| |
| #if defined(DART_PRECOMPILER) |
| |
| DEFINE_FLAG(bool, |
| resolve_dwarf_paths, |
| false, |
| "Resolve script URIs to absolute or relative file paths in DWARF"); |
| |
| DEFINE_FLAG(charp, |
| write_code_comments_as_synthetic_source_to, |
| nullptr, |
| "Print comments associated with instructions into the given file"); |
| |
| class DwarfPosition { |
| public: |
| DwarfPosition(int32_t line, int32_t column) : line_(line), column_(column) { |
| // Should only have no line information if also no column information. |
| ASSERT(line_ > kNoLine || column_ <= kNoColumn); |
| } |
| // CodeSourceMaps start the line and column registers at -1, not at 0, and |
| // the arguments passed to ChangePosition are retrieved from CodeSourceMaps. |
| explicit DwarfPosition(int32_t line) : DwarfPosition(line, -1) {} |
| constexpr DwarfPosition() : line_(-1), column_(-1) {} |
| |
| // The DWARF standard uses 0 to denote missing line or column |
| // information. |
| static constexpr int32_t kNoLine = 0; |
| static constexpr int32_t kNoColumn = 0; |
| |
| int32_t line() const { return line_ > kNoLine ? line_ : kNoLine; } |
| int32_t column() const { return column_ > kNoColumn ? column_ : kNoColumn; } |
| |
| // Adjusts the contents given the arguments to a ChangePosition instruction |
| // from CodeSourceMaps. |
| void ChangePosition(int32_t line_delta, int32_t new_column) { |
| line_ = Utils::AddWithWrapAround(line_, line_delta); |
| column_ = new_column; |
| } |
| |
| private: |
| int32_t line_; |
| int32_t column_; |
| }; |
| |
| static constexpr auto kNoDwarfPositionInfo = DwarfPosition(); |
| |
| class InliningNode : public ZoneAllocated { |
| public: |
| InliningNode(const Function& function, |
| const DwarfPosition& position, |
| int32_t start_pc_offset) |
| : function(function), |
| position(position), |
| start_pc_offset(start_pc_offset), |
| end_pc_offset(-1), |
| children_head(NULL), |
| children_tail(NULL), |
| children_next(NULL) { |
| RELEASE_ASSERT(!function.IsNull()); |
| RELEASE_ASSERT(function.IsNotTemporaryScopedHandle()); |
| } |
| |
| void AppendChild(InliningNode* child) { |
| if (children_tail == NULL) { |
| children_head = children_tail = child; |
| } else { |
| children_tail->children_next = child; |
| children_tail = child; |
| } |
| } |
| |
| const Function& function; |
| DwarfPosition position; |
| int32_t start_pc_offset; |
| int32_t end_pc_offset; |
| InliningNode* children_head; |
| InliningNode* children_tail; |
| InliningNode* children_next; |
| }; |
| |
| template <typename T> |
| Trie<T>* Trie<T>::AddString(Zone* zone, |
| Trie<T>* trie, |
| const char* key, |
| const T* value) { |
| ASSERT(key != nullptr); |
| if (trie == nullptr) { |
| trie = new (zone) Trie<T>(); |
| } |
| if (*key == '\0') { |
| ASSERT(trie->value_ == nullptr); |
| trie->value_ = value; |
| } else { |
| auto const index = ChildIndex(*key); |
| ASSERT(index >= 0 && index < kNumValidChars); |
| trie->children_[index] = |
| AddString(zone, trie->children_[index], key + 1, value); |
| } |
| |
| return trie; |
| } |
| |
| template <typename T> |
| const T* Trie<T>::Lookup(const Trie<T>* trie, const char* key, intptr_t* end) { |
| intptr_t i = 0; |
| for (; key[i] != '\0'; i++) { |
| auto const index = ChildIndex(key[i]); |
| ASSERT(index < kNumValidChars); |
| if (index < 0) { |
| if (end == nullptr) return nullptr; |
| break; |
| } |
| // Still find the longest valid trie prefix when no stored value. |
| if (trie == nullptr) continue; |
| trie = trie->children_[index]; |
| } |
| if (end != nullptr) { |
| *end = i; |
| } |
| if (trie == nullptr) return nullptr; |
| return trie->value_; |
| } |
| |
| Dwarf::Dwarf(Zone* zone) |
| : zone_(zone), |
| reverse_obfuscation_trie_(CreateReverseObfuscationTrie(zone)), |
| codes_(zone, 1024), |
| code_to_name_(zone), |
| functions_(zone, 1024), |
| function_to_index_(zone), |
| scripts_(zone, 1024), |
| script_to_index_(zone), |
| temp_(0) {} |
| |
| void Dwarf::AddCode(const Code& orig_code, const char* name) { |
| ASSERT(!orig_code.IsNull()); |
| ASSERT(name != nullptr); |
| |
| if (auto const old_pair = code_to_name_.Lookup(&orig_code)) { |
| // Dwarf objects can be shared, so we may get the same information for a |
| // given code object in different calls. In DEBUG mode, make sure the |
| // information is the same before returning. |
| ASSERT(old_pair->value != nullptr); |
| ASSERT_EQUAL(strcmp(old_pair->value, name), 0); |
| return; |
| } |
| |
| // Generate an appropriately zoned ZoneHandle for storing. |
| const auto& code = Code::ZoneHandle(zone_, orig_code.ptr()); |
| codes_.Add(&code); |
| // Currently assumes the name has the same lifetime as the Zone of the |
| // Dwarf object (which is currently true). Otherwise, need to copy. |
| code_to_name_.Insert({&code, name}); |
| |
| if (code.IsFunctionCode() && !code.IsUnknownDartCode()) { |
| const Function& function = Function::Handle(zone_, code.function()); |
| AddFunction(function); |
| } |
| const Array& inline_functions = |
| Array::Handle(zone_, code.inlined_id_to_function()); |
| if (!inline_functions.IsNull()) { |
| Function& function = Function::Handle(zone_); |
| for (intptr_t i = 0; i < inline_functions.Length(); i++) { |
| function ^= inline_functions.At(i); |
| AddFunction(function); |
| } |
| } |
| } |
| |
| intptr_t Dwarf::AddFunction(const Function& function) { |
| RELEASE_ASSERT(!function.IsNull()); |
| FunctionIndexPair* pair = function_to_index_.Lookup(&function); |
| if (pair != NULL) { |
| return pair->index_; |
| } |
| intptr_t index = functions_.length(); |
| const Function& zone_func = Function::ZoneHandle(zone_, function.ptr()); |
| function_to_index_.Insert(FunctionIndexPair(&zone_func, index)); |
| functions_.Add(&zone_func); |
| const Script& script = Script::Handle(zone_, function.script()); |
| AddScript(script); |
| return index; |
| } |
| |
| intptr_t Dwarf::AddScript(const Script& script) { |
| RELEASE_ASSERT(!script.IsNull()); |
| ScriptIndexPair* pair = script_to_index_.Lookup(&script); |
| if (pair != NULL) { |
| return pair->index_; |
| } |
| // DWARF file numbers start from 1. |
| intptr_t index = scripts_.length() + 1; |
| const Script& zone_script = Script::ZoneHandle(zone_, script.ptr()); |
| script_to_index_.Insert(ScriptIndexPair(&zone_script, index)); |
| scripts_.Add(&zone_script); |
| return index; |
| } |
| |
| intptr_t Dwarf::LookupFunction(const Function& function) { |
| RELEASE_ASSERT(!function.IsNull()); |
| FunctionIndexPair* pair = function_to_index_.Lookup(&function); |
| if (pair == NULL) { |
| FATAL1("Function detected too late during DWARF generation: %s", |
| function.ToCString()); |
| } |
| return pair->index_; |
| } |
| |
| intptr_t Dwarf::LookupScript(const Script& script) { |
| RELEASE_ASSERT(!script.IsNull()); |
| ScriptIndexPair* pair = script_to_index_.Lookup(&script); |
| if (pair == NULL) { |
| FATAL1("Script detected too late during DWARF generation: %s", |
| script.ToCString()); |
| } |
| return pair->index_; |
| } |
| |
| void Dwarf::WriteAbbreviations(DwarfWriteStream* stream) { |
| // Dwarf data mostly takes the form of a tree, whose nodes are called |
| // DIEs. Each DIE begins with an abbreviation code, and the abbreviation |
| // describes the attributes of that DIE and their representation. |
| |
| stream->uleb128(kCompilationUnit); // Abbrev code. |
| stream->uleb128(DW_TAG_compile_unit); // Type. |
| stream->u1(DW_CHILDREN_yes); |
| stream->uleb128(DW_AT_name); // Start of attributes. |
| stream->uleb128(DW_FORM_string); |
| stream->uleb128(DW_AT_producer); |
| stream->uleb128(DW_FORM_string); |
| stream->uleb128(DW_AT_comp_dir); |
| stream->uleb128(DW_FORM_string); |
| stream->uleb128(DW_AT_low_pc); |
| stream->uleb128(DW_FORM_addr); |
| stream->uleb128(DW_AT_high_pc); |
| stream->uleb128(DW_FORM_addr); |
| stream->uleb128(DW_AT_stmt_list); |
| stream->uleb128(DW_FORM_sec_offset); |
| stream->uleb128(0); |
| stream->uleb128(0); // End of attributes. |
| |
| stream->uleb128(kAbstractFunction); // Abbrev code. |
| stream->uleb128(DW_TAG_subprogram); // Type. |
| stream->u1(DW_CHILDREN_yes); |
| stream->uleb128(DW_AT_name); // Start of attributes. |
| stream->uleb128(DW_FORM_string); |
| stream->uleb128(DW_AT_decl_file); |
| stream->uleb128(DW_FORM_udata); |
| stream->uleb128(DW_AT_inline); |
| stream->uleb128(DW_FORM_udata); |
| stream->uleb128(0); |
| stream->uleb128(0); // End of attributes. |
| |
| stream->uleb128(kConcreteFunction); // Abbrev code. |
| stream->uleb128(DW_TAG_subprogram); // Type. |
| stream->u1(DW_CHILDREN_yes); |
| stream->uleb128(DW_AT_abstract_origin); // Start of attributes. |
| stream->uleb128(DW_FORM_ref4); |
| stream->uleb128(DW_AT_low_pc); |
| stream->uleb128(DW_FORM_addr); |
| stream->uleb128(DW_AT_high_pc); |
| stream->uleb128(DW_FORM_addr); |
| stream->uleb128(DW_AT_artificial); |
| stream->uleb128(DW_FORM_flag); |
| stream->uleb128(0); |
| stream->uleb128(0); // End of attributes. |
| |
| stream->uleb128(kInlinedFunction); // Abbrev code. |
| stream->uleb128(DW_TAG_inlined_subroutine); // Type. |
| stream->u1(DW_CHILDREN_yes); |
| stream->uleb128(DW_AT_abstract_origin); // Start of attributes. |
| stream->uleb128(DW_FORM_ref4); |
| stream->uleb128(DW_AT_low_pc); |
| stream->uleb128(DW_FORM_addr); |
| stream->uleb128(DW_AT_high_pc); |
| stream->uleb128(DW_FORM_addr); |
| stream->uleb128(DW_AT_call_file); |
| stream->uleb128(DW_FORM_udata); |
| stream->uleb128(DW_AT_call_line); |
| stream->uleb128(DW_FORM_udata); |
| stream->uleb128(DW_AT_call_column); |
| stream->uleb128(DW_FORM_udata); |
| stream->uleb128(0); |
| stream->uleb128(0); // End of attributes. |
| |
| stream->uleb128(0); // End of abbreviations. |
| } |
| |
| void Dwarf::WriteDebugInfo(DwarfWriteStream* stream) { |
| // 7.5.1.1 Compilation Unit Header |
| |
| // Unit length. |
| stream->WritePrefixedLength("cu", [&]() { |
| stream->u2(2); // DWARF version 2 |
| stream->u4(0); // debug_abbrev_offset |
| stream->u1(compiler::target::kWordSize); // address_size |
| |
| // Compilation Unit DIE. We describe the entire Dart program as a single |
| // compilation unit. Note we write attributes in the same order we declared |
| // them in our abbreviation above in WriteAbbreviations. |
| stream->uleb128(kCompilationUnit); |
| const Library& root_library = Library::Handle( |
| zone_, IsolateGroup::Current()->object_store()->root_library()); |
| const String& root_uri = String::Handle(zone_, root_library.url()); |
| stream->string(root_uri.ToCString()); // DW_AT_name |
| stream->string("Dart VM"); // DW_AT_producer |
| stream->string(""); // DW_AT_comp_dir |
| |
| // DW_AT_low_pc |
| // The lowest instruction address in this object file that is part of our |
| // compilation unit. Dwarf consumers use this to quickly decide which |
| // compilation unit DIE to consult for a given pc. |
| stream->OffsetFromSymbol(kIsolateSnapshotInstructionsAsmSymbol, 0); |
| |
| // DW_AT_high_pc |
| // The highest instruction address in this object file that is part of our |
| // compilation unit. Dwarf consumers use this to quickly decide which |
| // compilation unit DIE to consult for a given pc. |
| if (codes_.is_empty()) { |
| // No code objects in this program, so set high_pc to same as low_pc. |
| stream->OffsetFromSymbol(kIsolateSnapshotInstructionsAsmSymbol, 0); |
| } else { |
| const Code& last_code = *codes_.Last(); |
| auto const last_code_name = code_to_name_.LookupValue(&last_code); |
| ASSERT(last_code_name != nullptr); |
| stream->OffsetFromSymbol(last_code_name, last_code.Size()); |
| } |
| |
| // DW_AT_stmt_list (offset into .debug_line) |
| // Indicates which line number program is associated with this compilation |
| // unit. We only emit a single line number program. |
| stream->u4(0); |
| |
| WriteAbstractFunctions(stream); |
| WriteConcreteFunctions(stream); |
| |
| stream->uleb128(0); // End of children. |
| |
| stream->uleb128(0); // End of entries. |
| }); |
| } |
| |
| void Dwarf::WriteAbstractFunctions(DwarfWriteStream* stream) { |
| Script& script = Script::Handle(zone_); |
| String& name = String::Handle(zone_); |
| stream->InitializeAbstractOrigins(functions_.length()); |
| // By the point we're creating DWARF information, scripts have already lost |
| // their token stream and we can't look up their line number or column |
| // information, hence the lack of DW_AT_decl_line and DW_AT_decl_column. |
| for (intptr_t i = 0; i < functions_.length(); i++) { |
| const Function& function = *(functions_[i]); |
| name = function.QualifiedUserVisibleName(); |
| script = function.script(); |
| const intptr_t file = LookupScript(script); |
| auto const name_cstr = Deobfuscate(name.ToCString()); |
| |
| stream->RegisterAbstractOrigin(i); |
| stream->uleb128(kAbstractFunction); |
| stream->string(name_cstr); // DW_AT_name |
| stream->uleb128(file); // DW_AT_decl_file |
| stream->uleb128(DW_INL_inlined); // DW_AT_inline |
| stream->uleb128(0); // End of children. |
| } |
| } |
| |
| void Dwarf::WriteConcreteFunctions(DwarfWriteStream* stream) { |
| Function& function = Function::Handle(zone_); |
| Script& script = Script::Handle(zone_); |
| for (intptr_t i = 0; i < codes_.length(); i++) { |
| const Code& code = *(codes_[i]); |
| RELEASE_ASSERT(!code.IsNull()); |
| if (!code.IsFunctionCode() || code.IsUnknownDartCode()) { |
| continue; |
| } |
| |
| function = code.function(); |
| intptr_t function_index = LookupFunction(function); |
| script = function.script(); |
| const char* asm_name = code_to_name_.LookupValue(&code); |
| ASSERT(asm_name != nullptr); |
| |
| stream->uleb128(kConcreteFunction); |
| // DW_AT_abstract_origin |
| // References a node written above in WriteAbstractFunctions. |
| stream->AbstractOrigin(function_index); |
| |
| // DW_AT_low_pc |
| stream->OffsetFromSymbol(asm_name, 0); |
| // DW_AT_high_pc |
| stream->OffsetFromSymbol(asm_name, code.Size()); |
| // DW_AT_artificial |
| stream->u1(function.is_visible() ? 0 : 1); |
| |
| InliningNode* node = ExpandInliningTree(code); |
| if (node != NULL) { |
| for (InliningNode* child = node->children_head; child != NULL; |
| child = child->children_next) { |
| WriteInliningNode(stream, child, asm_name, script); |
| } |
| } |
| |
| stream->uleb128(0); // End of children. |
| } |
| } |
| |
| // Our state machine encodes position metadata such that we don't know the |
| // end pc for an inlined function until it is popped, but DWARF DIEs encode |
| // it where the function is pushed. We expand the state transitions into |
| // an in-memory tree to do the conversion. |
| InliningNode* Dwarf::ExpandInliningTree(const Code& code) { |
| const CodeSourceMap& map = |
| CodeSourceMap::Handle(zone_, code.code_source_map()); |
| if (map.IsNull()) { |
| return NULL; |
| } |
| const Array& functions = Array::Handle(zone_, code.inlined_id_to_function()); |
| const Function& root_function = Function::ZoneHandle(zone_, code.function()); |
| if (root_function.IsNull()) { |
| FATAL1("Wherefore art thou functionless code, %s?\n", code.ToCString()); |
| } |
| |
| GrowableArray<InliningNode*> node_stack(zone_, 4); |
| GrowableArray<DwarfPosition> token_positions(zone_, 4); |
| |
| NoSafepointScope no_safepoint; |
| ReadStream stream(map.Data(), map.Length()); |
| |
| int32_t current_pc_offset = 0; |
| token_positions.Add(kNoDwarfPositionInfo); |
| InliningNode* root_node = |
| new (zone_) InliningNode(root_function, token_positions.Last(), 0); |
| root_node->end_pc_offset = code.Size(); |
| node_stack.Add(root_node); |
| |
| while (stream.PendingBytes() > 0) { |
| int32_t arg1; |
| int32_t arg2 = -1; |
| const uint8_t opcode = CodeSourceMapOps::Read(&stream, &arg1, &arg2); |
| switch (opcode) { |
| case CodeSourceMapOps::kChangePosition: { |
| DwarfPosition& pos = token_positions[token_positions.length() - 1]; |
| pos.ChangePosition(arg1, arg2); |
| break; |
| } |
| case CodeSourceMapOps::kAdvancePC: { |
| current_pc_offset += arg1; |
| break; |
| } |
| case CodeSourceMapOps::kPushFunction: { |
| const Function& child_func = |
| Function::ZoneHandle(zone_, Function::RawCast(functions.At(arg1))); |
| InliningNode* child_node = new (zone_) |
| InliningNode(child_func, token_positions.Last(), current_pc_offset); |
| node_stack.Last()->AppendChild(child_node); |
| node_stack.Add(child_node); |
| token_positions.Add(kNoDwarfPositionInfo); |
| break; |
| } |
| case CodeSourceMapOps::kPopFunction: { |
| // We never pop the root function. |
| ASSERT(node_stack.length() > 1); |
| ASSERT(token_positions.length() > 1); |
| node_stack.Last()->end_pc_offset = current_pc_offset; |
| node_stack.RemoveLast(); |
| token_positions.RemoveLast(); |
| break; |
| } |
| case CodeSourceMapOps::kNullCheck: { |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| while (node_stack.length() > 1) { |
| node_stack.Last()->end_pc_offset = current_pc_offset; |
| node_stack.RemoveLast(); |
| token_positions.RemoveLast(); |
| } |
| ASSERT(node_stack[0] == root_node); |
| return root_node; |
| } |
| |
| void Dwarf::WriteInliningNode(DwarfWriteStream* stream, |
| InliningNode* node, |
| const char* root_asm_name, |
| const Script& parent_script) { |
| intptr_t file = LookupScript(parent_script); |
| intptr_t function_index = LookupFunction(node->function); |
| const Script& script = Script::Handle(zone_, node->function.script()); |
| |
| stream->uleb128(kInlinedFunction); |
| // DW_AT_abstract_origin |
| // References a node written above in WriteAbstractFunctions. |
| stream->AbstractOrigin(function_index); |
| |
| // DW_AT_low_pc |
| stream->OffsetFromSymbol(root_asm_name, node->start_pc_offset); |
| // DW_AT_high_pc |
| stream->OffsetFromSymbol(root_asm_name, node->end_pc_offset); |
| // DW_AT_call_file |
| stream->uleb128(file); |
| |
| // DW_AT_call_line |
| stream->uleb128(node->position.line()); |
| // DW_at_call_column |
| stream->uleb128(node->position.column()); |
| |
| for (InliningNode* child = node->children_head; child != NULL; |
| child = child->children_next) { |
| WriteInliningNode(stream, child, root_asm_name, script); |
| } |
| |
| stream->uleb128(0); // End of children. |
| } |
| |
| // Helper class for tracking state of DWARF registers and emitting |
| // line number program commands to set these registers to the right |
| // state. |
| class LineNumberProgramWriter { |
| public: |
| explicit LineNumberProgramWriter(DwarfWriteStream* stream) |
| : stream_(stream) {} |
| |
| void EmitRow(intptr_t file, |
| intptr_t line, |
| intptr_t column, |
| const char* asm_name, |
| intptr_t pc_offset) { |
| if (AddRow(file, line, column, asm_name, pc_offset)) { |
| // Address register must be updated from 0 before emitting an LNP row |
| // (dartbug.com/41756). |
| stream_->u1(Dwarf::DW_LNS_copy); |
| } |
| } |
| |
| // Associates the given file, line, and column information for the instruction |
| // at the pc_offset into the instructions payload of the Code object with the |
| // symbol asm_name. Returns whether any changes were made to the stream. |
| bool AddRow(intptr_t file, |
| intptr_t line, |
| intptr_t column, |
| const char* asm_name, |
| intptr_t pc_offset) { |
| ASSERT_EQUAL(end_sequence_, false); |
| bool source_info_changed = false; |
| // Note that files are 1-indexed. |
| ASSERT(file >= 1); |
| if (file != file_) { |
| stream_->u1(Dwarf::DW_LNS_set_file); |
| stream_->uleb128(file); |
| file_ = file; |
| source_info_changed = true; |
| } |
| ASSERT(line >= DwarfPosition::kNoLine); |
| if (line != line_) { |
| stream_->u1(Dwarf::DW_LNS_advance_line); |
| stream_->sleb128(line - line_); |
| line_ = line; |
| source_info_changed = true; |
| } |
| ASSERT(column >= DwarfPosition::kNoColumn); |
| if (column != column_) { |
| stream_->u1(Dwarf::DW_LNS_set_column); |
| stream_->uleb128(column); |
| column_ = column; |
| source_info_changed = true; |
| } |
| // If the file, line, and column information match that for the previous |
| // AddRow call, no change is made to the stream. This is because all |
| // addresses between two line number program rows inherit the source |
| // information from the first. |
| if (source_info_changed) { |
| SetCurrentPosition(asm_name, pc_offset); |
| } |
| return source_info_changed; |
| } |
| |
| void MarkEnd() { |
| ASSERT_EQUAL(end_sequence_, false); |
| // End of contiguous machine code. |
| stream_->u1(0); // This is an extended opcode |
| stream_->u1(1); // that is 1 byte long |
| stream_->u1(Dwarf::DW_LNE_end_sequence); |
| end_sequence_ = true; |
| } |
| |
| void MarkEnd(const char* asm_name, intptr_t pc_offset) { |
| ASSERT_EQUAL(end_sequence_, false); |
| SetCurrentPosition(asm_name, pc_offset); |
| MarkEnd(); |
| } |
| |
| private: |
| void SetCurrentPosition(const char* asm_name, intptr_t pc_offset) { |
| // Each LNP row is either in a different function from the previous row |
| // or is at an increasing PC offset into the same function. |
| ASSERT(asm_name != nullptr); |
| ASSERT(pc_offset >= 0); |
| ASSERT(asm_name_ != asm_name || pc_offset > pc_offset_); |
| if (asm_name_ != asm_name) { |
| // Set the address register to the given offset into the new code payload. |
| auto const instr_size = 1 + compiler::target::kWordSize; |
| stream_->u1(0); // This is an extended opcode |
| stream_->u1(instr_size); // that is 5 or 9 bytes long |
| stream_->u1(Dwarf::DW_LNE_set_address); |
| stream_->OffsetFromSymbol(asm_name, pc_offset); |
| } else { |
| // Change the address register by the difference in the two offsets. |
| stream_->u1(Dwarf::DW_LNS_advance_pc); |
| stream_->uleb128(pc_offset - pc_offset_); |
| } |
| asm_name_ = asm_name; |
| pc_offset_ = pc_offset; |
| } |
| |
| DwarfWriteStream* const stream_; |
| // The initial values for the line number program state machine registers |
| // according to the DWARF standard. |
| intptr_t pc_offset_ = 0; |
| intptr_t file_ = 1; |
| intptr_t line_ = 1; |
| intptr_t column_ = 0; |
| intptr_t end_sequence_ = false; |
| |
| // Other info not stored in the state machine registers. |
| const char* asm_name_ = nullptr; |
| }; |
| |
| void Dwarf::WriteSyntheticLineNumberProgram(LineNumberProgramWriter* writer) { |
| // We emit it last after all other scripts. |
| const intptr_t comments_file_index = scripts_.length() + 1; |
| |
| auto file_open = Dart::file_open_callback(); |
| auto file_write = Dart::file_write_callback(); |
| auto file_close = Dart::file_close_callback(); |
| if ((file_open == nullptr) || (file_write == nullptr) || |
| (file_close == nullptr)) { |
| return; |
| } |
| |
| TextBuffer comments_buffer(128 * KB); |
| |
| auto comments_file = file_open( |
| FLAG_write_code_comments_as_synthetic_source_to, /*write=*/true); |
| if (comments_file == nullptr) { |
| OS::PrintErr("Failed to open file %s\n", |
| FLAG_write_code_comments_as_synthetic_source_to); |
| return; |
| } |
| |
| // Lines in DWARF are 1-indexed. |
| intptr_t current_line = 1; |
| |
| for (intptr_t i = 0; i < codes_.length(); i++) { |
| const Code& code = *(codes_[i]); |
| auto const asm_name = code_to_name_.LookupValue(&code); |
| ASSERT(asm_name != nullptr); |
| |
| auto& comments = code.comments(); |
| for (intptr_t i = 0, len = comments.Length(); i < len;) { |
| intptr_t current_pc_offset = comments.PCOffsetAt(i); |
| writer->AddRow(comments_file_index, current_line, |
| DwarfPosition::kNoColumn, asm_name, current_pc_offset); |
| while (i < len && current_pc_offset == comments.PCOffsetAt(i)) { |
| comments_buffer.AddString(comments.CommentAt(i)); |
| comments_buffer.AddChar('\n'); |
| current_line++; |
| i++; |
| } |
| } |
| } |
| |
| file_write(comments_buffer.buffer(), comments_buffer.length(), comments_file); |
| file_close(comments_file); |
| } |
| |
| void Dwarf::WriteLineNumberProgramFromCodeSourceMaps( |
| LineNumberProgramWriter* writer) { |
| Function& root_function = Function::Handle(zone_); |
| Script& script = Script::Handle(zone_); |
| CodeSourceMap& map = CodeSourceMap::Handle(zone_); |
| Array& functions = Array::Handle(zone_); |
| GrowableArray<const Function*> function_stack(zone_, 8); |
| GrowableArray<DwarfPosition> token_positions(zone_, 8); |
| |
| for (intptr_t i = 0; i < codes_.length(); i++) { |
| const Code& code = *(codes_[i]); |
| auto const asm_name = code_to_name_.LookupValue(&code); |
| ASSERT(asm_name != nullptr); |
| |
| map = code.code_source_map(); |
| if (map.IsNull()) { |
| continue; |
| } |
| root_function = code.function(); |
| functions = code.inlined_id_to_function(); |
| |
| NoSafepointScope no_safepoint; |
| ReadStream code_map_stream(map.Data(), map.Length()); |
| |
| function_stack.Clear(); |
| token_positions.Clear(); |
| |
| int32_t current_pc_offset = 0; |
| function_stack.Add(&root_function); |
| token_positions.Add(kNoDwarfPositionInfo); |
| |
| while (code_map_stream.PendingBytes() > 0) { |
| int32_t arg1; |
| int32_t arg2 = -1; |
| const uint8_t opcode = |
| CodeSourceMapOps::Read(&code_map_stream, &arg1, &arg2); |
| switch (opcode) { |
| case CodeSourceMapOps::kChangePosition: { |
| DwarfPosition& pos = token_positions[token_positions.length() - 1]; |
| pos.ChangePosition(arg1, arg2); |
| break; |
| } |
| case CodeSourceMapOps::kAdvancePC: { |
| // Emit a row for the previous PC value if the source location |
| // changed since the last row was emitted. |
| const Function& function = *(function_stack.Last()); |
| script = function.script(); |
| const intptr_t file = LookupScript(script); |
| const intptr_t line = token_positions.Last().line(); |
| const intptr_t column = token_positions.Last().column(); |
| writer->EmitRow(file, line, column, asm_name, current_pc_offset); |
| |
| current_pc_offset += arg1; |
| break; |
| } |
| case CodeSourceMapOps::kPushFunction: { |
| auto child_func = |
| &Function::Handle(zone_, Function::RawCast(functions.At(arg1))); |
| function_stack.Add(child_func); |
| token_positions.Add(kNoDwarfPositionInfo); |
| break; |
| } |
| case CodeSourceMapOps::kPopFunction: { |
| // We never pop the root function. |
| ASSERT(function_stack.length() > 1); |
| ASSERT(token_positions.length() > 1); |
| function_stack.RemoveLast(); |
| token_positions.RemoveLast(); |
| break; |
| } |
| case CodeSourceMapOps::kNullCheck: { |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| } |
| } |
| |
| static constexpr char kResolvedFileRoot[] = "file:///"; |
| static constexpr intptr_t kResolvedFileRootLen = sizeof(kResolvedFileRoot) - 1; |
| static constexpr char kResolvedSdkRoot[] = "org-dartlang-sdk:///sdk/"; |
| static constexpr intptr_t kResolvedSdkRootLen = sizeof(kResolvedSdkRoot) - 1; |
| |
| static const char* ConvertResolvedURI(const char* str) { |
| const intptr_t len = strlen(str); |
| if (len > kResolvedFileRootLen && |
| strncmp(str, kResolvedFileRoot, kResolvedFileRootLen) == 0) { |
| #if defined(DART_HOST_OS_WINDOWS) |
| return str + kResolvedFileRootLen; // Strip off the entire prefix. |
| #else |
| return str + kResolvedFileRootLen - 1; // Leave a '/' on the front. |
| #endif |
| } |
| if (len > kResolvedSdkRootLen && |
| strncmp(str, kResolvedSdkRoot, kResolvedSdkRootLen) == 0) { |
| // Leave "sdk/" as a prefix in the returned path. |
| return str + (kResolvedSdkRootLen - 4); |
| } |
| return nullptr; |
| } |
| |
| void Dwarf::WriteLineNumberProgram(DwarfWriteStream* stream) { |
| // 6.2.4 The Line Number Program Header |
| |
| // 1. unit_length. This encoding implies 32-bit DWARF. |
| stream->WritePrefixedLength("line", [&]() { |
| stream->u2(2); // 2. DWARF version 2 |
| |
| // 3. header_length |
| stream->WritePrefixedLength("lineheader", [&]() { |
| stream->u1(1); // 4. minimum_instruction_length |
| stream->u1(1); // 5. default_is_stmt (true for dsymutil compatibility). |
| stream->u1(0); // 6. line_base |
| stream->u1(1); // 7. line_range |
| stream->u1(13); // 8. opcode_base (12 standard opcodes in Dwarf 2) |
| |
| // 9. standard_opcode_lengths |
| stream->u1(0); // DW_LNS_copy, 0 operands |
| stream->u1(1); // DW_LNS_advance_pc, 1 operands |
| stream->u1(1); // DW_LNS_advance_list, 1 operands |
| stream->u1(1); // DW_LNS_set_file, 1 operands |
| stream->u1(1); // DW_LNS_set_column, 1 operands |
| stream->u1(0); // DW_LNS_negate_stmt, 0 operands |
| stream->u1(0); // DW_LNS_set_basic_block, 0 operands |
| stream->u1(0); // DW_LNS_const_add_pc, 0 operands |
| stream->u1(1); // DW_LNS_fixed_advance_pc, 1 operands |
| stream->u1(0); // DW_LNS_set_prolog_end, 0 operands |
| stream->u1(0); // DW_LNS_set_epligoue_begin, 0 operands |
| stream->u1(1); // DW_LNS_set_isa, 1 operands |
| |
| // 10. include_directories (sequence of path names) |
| // We don't emit any because we use full paths below. |
| stream->u1(0); |
| |
| // 11. file_names (sequence of file entries) |
| String& uri = String::Handle(zone_); |
| for (intptr_t i = 0; i < scripts_.length(); i++) { |
| const Script& script = *(scripts_[i]); |
| if (FLAG_resolve_dwarf_paths) { |
| uri = script.resolved_url(); |
| // Strictly enforce this to catch unresolvable cases. |
| if (uri.IsNull()) { |
| FATAL("no resolved URI for Script %s available", |
| script.ToCString()); |
| } |
| } else { |
| uri = script.url(); |
| } |
| ASSERT(!uri.IsNull()); |
| auto uri_cstr = Deobfuscate(uri.ToCString()); |
| if (FLAG_resolve_dwarf_paths) { |
| auto const converted_cstr = ConvertResolvedURI(uri_cstr); |
| // Strictly enforce this to catch inconvertable cases. |
| if (converted_cstr == nullptr) { |
| FATAL("cannot convert resolved URI %s", uri_cstr); |
| } |
| uri_cstr = converted_cstr; |
| } |
| RELEASE_ASSERT(strlen(uri_cstr) != 0); |
| |
| stream->string(uri_cstr); // NOLINT |
| stream->uleb128(0); // Include directory index. |
| stream->uleb128(0); // File modification time. |
| stream->uleb128(0); // File length. |
| } |
| if (FLAG_write_code_comments_as_synthetic_source_to != nullptr) { |
| stream->string( // NOLINT |
| FLAG_write_code_comments_as_synthetic_source_to); |
| stream->uleb128(0); // Include directory index. |
| stream->uleb128(0); // File modification time. |
| stream->uleb128(0); // File length. |
| } |
| stream->u1(0); // End of file names. |
| }); |
| |
| // 6.2.5 The Line Number Program |
| LineNumberProgramWriter lnp_writer(stream); |
| if (FLAG_write_code_comments_as_synthetic_source_to != nullptr) { |
| WriteSyntheticLineNumberProgram(&lnp_writer); |
| } else { |
| WriteLineNumberProgramFromCodeSourceMaps(&lnp_writer); |
| } |
| |
| // Advance pc to end of the compilation unit if not already there. |
| if (codes_.length() != 0) { |
| const intptr_t last_code_index = codes_.length() - 1; |
| const Code& last_code = *(codes_[last_code_index]); |
| const intptr_t last_pc_offset = last_code.Size(); |
| const char* last_asm_name = code_to_name_.LookupValue(&last_code); |
| ASSERT(last_asm_name != nullptr); |
| lnp_writer.MarkEnd(last_asm_name, last_pc_offset); |
| } else { |
| lnp_writer.MarkEnd(); |
| } |
| }); |
| } |
| |
| const char* Dwarf::Deobfuscate(const char* cstr) { |
| if (reverse_obfuscation_trie_ == nullptr) return cstr; |
| TextBuffer buffer(256); |
| // Used to avoid Zone-allocating strings if no deobfuscation was performed. |
| bool changed = false; |
| intptr_t i = 0; |
| while (cstr[i] != '\0') { |
| intptr_t offset; |
| auto const value = reverse_obfuscation_trie_->Lookup(cstr + i, &offset); |
| if (offset == 0) { |
| // The first character was an invalid key element (that isn't the null |
| // terminator due to the while condition), copy it and skip to the next. |
| buffer.AddChar(cstr[i++]); |
| } else if (value != nullptr) { |
| changed = true; |
| buffer.AddString(value); |
| } else { |
| buffer.AddRaw(reinterpret_cast<const uint8_t*>(cstr + i), offset); |
| } |
| i += offset; |
| } |
| if (!changed) return cstr; |
| return OS::SCreate(zone_, "%s", buffer.buffer()); |
| } |
| |
| Trie<const char>* Dwarf::CreateReverseObfuscationTrie(Zone* zone) { |
| auto const map_array = IsolateGroup::Current()->obfuscation_map(); |
| if (map_array == nullptr) return nullptr; |
| |
| Trie<const char>* trie = nullptr; |
| for (intptr_t i = 0; map_array[i] != nullptr; i += 2) { |
| auto const key = map_array[i]; |
| auto const value = map_array[i + 1]; |
| ASSERT(value != nullptr); |
| // Don't include identity mappings. |
| if (strcmp(key, value) == 0) continue; |
| // Otherwise, any value in the obfuscation map should be a valid key. |
| ASSERT(Trie<const char>::IsValidKey(value)); |
| trie = Trie<const char>::AddString(zone, trie, value, key); |
| } |
| return trie; |
| } |
| |
| #endif // DART_PRECOMPILER |
| |
| } // namespace dart |