| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/signature.h" |
| |
| #include "src/handles.h" |
| #include "src/v8.h" |
| #include "src/zone/zone-containers.h" |
| |
| #include "src/wasm/ast-decoder.h" |
| #include "src/wasm/leb-helper.h" |
| #include "src/wasm/wasm-macro-gen.h" |
| #include "src/wasm/wasm-module-builder.h" |
| #include "src/wasm/wasm-module.h" |
| #include "src/wasm/wasm-opcodes.h" |
| |
| #include "src/v8memory.h" |
| |
| #if DEBUG |
| #define TRACE(...) \ |
| do { \ |
| if (FLAG_trace_wasm_encoder) PrintF(__VA_ARGS__); \ |
| } while (false) |
| #else |
| #define TRACE(...) |
| #endif |
| |
| namespace v8 { |
| namespace internal { |
| namespace wasm { |
| |
| // Emit a section code and the size as a padded varint that can be patched |
| // later. |
| size_t EmitSection(WasmSectionCode code, ZoneBuffer& buffer) { |
| // Emit the section code. |
| buffer.write_u8(code); |
| |
| // Emit a placeholder for the length. |
| return buffer.reserve_u32v(); |
| } |
| |
| // Patch the size of a section after it's finished. |
| void FixupSection(ZoneBuffer& buffer, size_t start) { |
| buffer.patch_u32v(start, static_cast<uint32_t>(buffer.offset() - start - |
| kPaddedVarInt32Size)); |
| } |
| |
| WasmFunctionBuilder::WasmFunctionBuilder(WasmModuleBuilder* builder) |
| : builder_(builder), |
| locals_(builder->zone()), |
| signature_index_(0), |
| exported_(0), |
| func_index_(static_cast<uint32_t>(builder->functions_.size())), |
| body_(builder->zone()), |
| name_(builder->zone()), |
| exported_name_(builder->zone()), |
| i32_temps_(builder->zone()), |
| i64_temps_(builder->zone()), |
| f32_temps_(builder->zone()), |
| f64_temps_(builder->zone()), |
| direct_calls_(builder->zone()) {} |
| |
| void WasmFunctionBuilder::EmitVarInt(uint32_t val) { |
| byte buffer[8]; |
| byte* ptr = buffer; |
| LEBHelper::write_u32v(&ptr, val); |
| for (byte* p = buffer; p < ptr; p++) { |
| body_.push_back(*p); |
| } |
| } |
| |
| void WasmFunctionBuilder::SetSignature(FunctionSig* sig) { |
| DCHECK(!locals_.has_sig()); |
| locals_.set_sig(sig); |
| signature_index_ = builder_->AddSignature(sig); |
| } |
| |
| uint32_t WasmFunctionBuilder::AddLocal(LocalType type) { |
| DCHECK(locals_.has_sig()); |
| return locals_.AddLocals(1, type); |
| } |
| |
| void WasmFunctionBuilder::EmitGetLocal(uint32_t local_index) { |
| EmitWithVarInt(kExprGetLocal, local_index); |
| } |
| |
| void WasmFunctionBuilder::EmitSetLocal(uint32_t local_index) { |
| EmitWithVarInt(kExprSetLocal, local_index); |
| } |
| |
| void WasmFunctionBuilder::EmitTeeLocal(uint32_t local_index) { |
| EmitWithVarInt(kExprTeeLocal, local_index); |
| } |
| |
| void WasmFunctionBuilder::EmitCode(const byte* code, uint32_t code_size) { |
| for (size_t i = 0; i < code_size; ++i) { |
| body_.push_back(code[i]); |
| } |
| } |
| |
| void WasmFunctionBuilder::Emit(WasmOpcode opcode) { |
| body_.push_back(static_cast<byte>(opcode)); |
| } |
| |
| void WasmFunctionBuilder::EmitWithU8(WasmOpcode opcode, const byte immediate) { |
| body_.push_back(static_cast<byte>(opcode)); |
| body_.push_back(immediate); |
| } |
| |
| void WasmFunctionBuilder::EmitWithU8U8(WasmOpcode opcode, const byte imm1, |
| const byte imm2) { |
| body_.push_back(static_cast<byte>(opcode)); |
| body_.push_back(imm1); |
| body_.push_back(imm2); |
| } |
| |
| void WasmFunctionBuilder::EmitWithVarInt(WasmOpcode opcode, |
| uint32_t immediate) { |
| body_.push_back(static_cast<byte>(opcode)); |
| EmitVarInt(immediate); |
| } |
| |
| void WasmFunctionBuilder::EmitI32Const(int32_t value) { |
| // TODO(titzer): variable-length signed and unsigned i32 constants. |
| if (-128 <= value && value <= 127) { |
| EmitWithU8(kExprI8Const, static_cast<byte>(value)); |
| } else { |
| byte code[] = {WASM_I32V_5(value)}; |
| EmitCode(code, sizeof(code)); |
| } |
| } |
| |
| void WasmFunctionBuilder::EmitDirectCallIndex(uint32_t index) { |
| DirectCallIndex call; |
| call.offset = body_.size(); |
| call.direct_index = index; |
| direct_calls_.push_back(call); |
| byte code[] = {U32V_5(0)}; |
| EmitCode(code, sizeof(code)); |
| } |
| |
| void WasmFunctionBuilder::Export() { exported_ = true; } |
| |
| void WasmFunctionBuilder::ExportAs(Vector<const char> name) { |
| exported_ = true; |
| exported_name_.resize(name.length()); |
| memcpy(exported_name_.data(), name.start(), name.length()); |
| } |
| |
| void WasmFunctionBuilder::SetName(Vector<const char> name) { |
| name_.resize(name.length()); |
| memcpy(name_.data(), name.start(), name.length()); |
| } |
| |
| void WasmFunctionBuilder::WriteSignature(ZoneBuffer& buffer) const { |
| buffer.write_u32v(signature_index_); |
| } |
| |
| void WasmFunctionBuilder::WriteExport(ZoneBuffer& buffer) const { |
| if (exported_) { |
| const ZoneVector<char>* exported_name = |
| exported_name_.size() == 0 ? &name_ : &exported_name_; |
| buffer.write_size(exported_name->size()); |
| buffer.write(reinterpret_cast<const byte*>(exported_name->data()), |
| exported_name->size()); |
| buffer.write_u8(kExternalFunction); |
| buffer.write_u32v(func_index_ + |
| static_cast<uint32_t>(builder_->imports_.size())); |
| } |
| } |
| |
| void WasmFunctionBuilder::WriteBody(ZoneBuffer& buffer) const { |
| size_t locals_size = locals_.Size(); |
| buffer.write_size(locals_size + body_.size()); |
| buffer.EnsureSpace(locals_size); |
| byte** ptr = buffer.pos_ptr(); |
| locals_.Emit(*ptr); |
| (*ptr) += locals_size; // UGLY: manual bump of position pointer |
| if (body_.size() > 0) { |
| size_t base = buffer.offset(); |
| buffer.write(&body_[0], body_.size()); |
| for (DirectCallIndex call : direct_calls_) { |
| buffer.patch_u32v( |
| base + call.offset, |
| call.direct_index + static_cast<uint32_t>(builder_->imports_.size())); |
| } |
| } |
| } |
| |
| WasmModuleBuilder::WasmModuleBuilder(Zone* zone) |
| : zone_(zone), |
| signatures_(zone), |
| imports_(zone), |
| functions_(zone), |
| data_segments_(zone), |
| indirect_functions_(zone), |
| globals_(zone), |
| signature_map_(zone), |
| start_function_index_(-1) {} |
| |
| WasmFunctionBuilder* WasmModuleBuilder::AddFunction(FunctionSig* sig) { |
| functions_.push_back(new (zone_) WasmFunctionBuilder(this)); |
| // Add the signature if one was provided here. |
| if (sig) functions_.back()->SetSignature(sig); |
| return functions_.back(); |
| } |
| |
| void WasmModuleBuilder::AddDataSegment(const byte* data, uint32_t size, |
| uint32_t dest) { |
| data_segments_.push_back({ZoneVector<byte>(zone()), dest}); |
| ZoneVector<byte>& vec = data_segments_.back().data; |
| for (uint32_t i = 0; i < size; i++) { |
| vec.push_back(data[i]); |
| } |
| } |
| |
| bool WasmModuleBuilder::CompareFunctionSigs::operator()(FunctionSig* a, |
| FunctionSig* b) const { |
| if (a->return_count() < b->return_count()) return true; |
| if (a->return_count() > b->return_count()) return false; |
| if (a->parameter_count() < b->parameter_count()) return true; |
| if (a->parameter_count() > b->parameter_count()) return false; |
| for (size_t r = 0; r < a->return_count(); r++) { |
| if (a->GetReturn(r) < b->GetReturn(r)) return true; |
| if (a->GetReturn(r) > b->GetReturn(r)) return false; |
| } |
| for (size_t p = 0; p < a->parameter_count(); p++) { |
| if (a->GetParam(p) < b->GetParam(p)) return true; |
| if (a->GetParam(p) > b->GetParam(p)) return false; |
| } |
| return false; |
| } |
| |
| uint32_t WasmModuleBuilder::AddSignature(FunctionSig* sig) { |
| SignatureMap::iterator pos = signature_map_.find(sig); |
| if (pos != signature_map_.end()) { |
| return pos->second; |
| } else { |
| uint32_t index = static_cast<uint32_t>(signatures_.size()); |
| signature_map_[sig] = index; |
| signatures_.push_back(sig); |
| return index; |
| } |
| } |
| |
| void WasmModuleBuilder::AddIndirectFunction(uint32_t index) { |
| indirect_functions_.push_back(index); |
| } |
| |
| uint32_t WasmModuleBuilder::AddImport(const char* name, int name_length, |
| FunctionSig* sig) { |
| imports_.push_back({AddSignature(sig), name, name_length}); |
| return static_cast<uint32_t>(imports_.size() - 1); |
| } |
| |
| void WasmModuleBuilder::MarkStartFunction(WasmFunctionBuilder* function) { |
| start_function_index_ = function->func_index(); |
| } |
| |
| uint32_t WasmModuleBuilder::AddGlobal(LocalType type, bool exported, |
| bool mutability, |
| const WasmInitExpr& init) { |
| globals_.push_back({type, exported, mutability, init}); |
| return static_cast<uint32_t>(globals_.size() - 1); |
| } |
| |
| void WasmModuleBuilder::WriteTo(ZoneBuffer& buffer) const { |
| uint32_t exports = 0; |
| |
| // == Emit magic ============================================================= |
| TRACE("emit magic\n"); |
| buffer.write_u32(kWasmMagic); |
| buffer.write_u32(kWasmVersion); |
| |
| // == Emit signatures ======================================================== |
| if (signatures_.size() > 0) { |
| size_t start = EmitSection(kTypeSectionCode, buffer); |
| buffer.write_size(signatures_.size()); |
| |
| for (FunctionSig* sig : signatures_) { |
| buffer.write_u8(kWasmFunctionTypeForm); |
| buffer.write_size(sig->parameter_count()); |
| for (size_t j = 0; j < sig->parameter_count(); j++) { |
| buffer.write_u8(WasmOpcodes::LocalTypeCodeFor(sig->GetParam(j))); |
| } |
| buffer.write_size(sig->return_count()); |
| for (size_t j = 0; j < sig->return_count(); j++) { |
| buffer.write_u8(WasmOpcodes::LocalTypeCodeFor(sig->GetReturn(j))); |
| } |
| } |
| FixupSection(buffer, start); |
| } |
| |
| // == Emit imports =========================================================== |
| if (imports_.size() > 0) { |
| size_t start = EmitSection(kImportSectionCode, buffer); |
| buffer.write_size(imports_.size()); |
| for (auto import : imports_) { |
| buffer.write_u32v(import.name_length); // module name length |
| buffer.write(reinterpret_cast<const byte*>(import.name), // module name |
| import.name_length); |
| buffer.write_u32v(0); // field name length |
| buffer.write_u8(kExternalFunction); |
| buffer.write_u32v(import.sig_index); |
| } |
| FixupSection(buffer, start); |
| } |
| |
| // == Emit function signatures =============================================== |
| bool has_names = false; |
| if (functions_.size() > 0) { |
| size_t start = EmitSection(kFunctionSectionCode, buffer); |
| buffer.write_size(functions_.size()); |
| for (auto function : functions_) { |
| function->WriteSignature(buffer); |
| if (function->exported()) exports++; |
| if (function->name_.size() > 0) has_names = true; |
| } |
| FixupSection(buffer, start); |
| } |
| |
| // == emit function table ==================================================== |
| if (indirect_functions_.size() > 0) { |
| size_t start = EmitSection(kTableSectionCode, buffer); |
| buffer.write_u8(1); // table count |
| buffer.write_u8(kWasmAnyFunctionTypeForm); |
| buffer.write_u8(kResizableMaximumFlag); |
| buffer.write_size(indirect_functions_.size()); |
| buffer.write_size(indirect_functions_.size()); |
| FixupSection(buffer, start); |
| } |
| |
| // == emit memory declaration ================================================ |
| { |
| size_t start = EmitSection(kMemorySectionCode, buffer); |
| buffer.write_u8(1); // memory count |
| buffer.write_u32v(kResizableMaximumFlag); |
| buffer.write_u32v(16); // min memory size |
| buffer.write_u32v(16); // max memory size |
| FixupSection(buffer, start); |
| } |
| |
| // == Emit globals =========================================================== |
| if (globals_.size() > 0) { |
| size_t start = EmitSection(kGlobalSectionCode, buffer); |
| buffer.write_size(globals_.size()); |
| |
| for (auto global : globals_) { |
| buffer.write_u8(WasmOpcodes::LocalTypeCodeFor(global.type)); |
| buffer.write_u8(global.mutability ? 1 : 0); |
| switch (global.init.kind) { |
| case WasmInitExpr::kI32Const: { |
| DCHECK_EQ(kAstI32, global.type); |
| const byte code[] = {WASM_I32V_5(global.init.val.i32_const)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case WasmInitExpr::kI64Const: { |
| DCHECK_EQ(kAstI64, global.type); |
| const byte code[] = {WASM_I64V_10(global.init.val.i64_const)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case WasmInitExpr::kF32Const: { |
| DCHECK_EQ(kAstF32, global.type); |
| const byte code[] = {WASM_F32(global.init.val.f32_const)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case WasmInitExpr::kF64Const: { |
| DCHECK_EQ(kAstF64, global.type); |
| const byte code[] = {WASM_F64(global.init.val.f64_const)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case WasmInitExpr::kGlobalIndex: { |
| const byte code[] = {kExprGetGlobal, |
| U32V_5(global.init.val.global_index)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| default: { |
| // No initializer, emit a default value. |
| switch (global.type) { |
| case kAstI32: { |
| const byte code[] = {WASM_I32V_1(0)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case kAstI64: { |
| const byte code[] = {WASM_I64V_1(0)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case kAstF32: { |
| const byte code[] = {WASM_F32(0.0)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| case kAstF64: { |
| const byte code[] = {WASM_F64(0.0)}; |
| buffer.write(code, sizeof(code)); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| } |
| } |
| buffer.write_u8(kExprEnd); |
| } |
| FixupSection(buffer, start); |
| } |
| |
| // == emit exports =========================================================== |
| if (exports > 0) { |
| size_t start = EmitSection(kExportSectionCode, buffer); |
| buffer.write_u32v(exports); |
| for (auto function : functions_) function->WriteExport(buffer); |
| FixupSection(buffer, start); |
| } |
| |
| // == emit start function index ============================================== |
| if (start_function_index_ >= 0) { |
| size_t start = EmitSection(kStartSectionCode, buffer); |
| buffer.write_u32v(start_function_index_ + |
| static_cast<uint32_t>(imports_.size())); |
| FixupSection(buffer, start); |
| } |
| |
| // == emit function table elements =========================================== |
| if (indirect_functions_.size() > 0) { |
| size_t start = EmitSection(kElementSectionCode, buffer); |
| buffer.write_u8(1); // count of entries |
| buffer.write_u8(0); // table index |
| buffer.write_u8(kExprI32Const); // offset |
| buffer.write_u32v(0); |
| buffer.write_u8(kExprEnd); |
| buffer.write_size(indirect_functions_.size()); // element count |
| |
| for (auto index : indirect_functions_) { |
| buffer.write_u32v(index + static_cast<uint32_t>(imports_.size())); |
| } |
| |
| FixupSection(buffer, start); |
| } |
| |
| // == emit code ============================================================== |
| if (functions_.size() > 0) { |
| size_t start = EmitSection(kCodeSectionCode, buffer); |
| buffer.write_size(functions_.size()); |
| for (auto function : functions_) { |
| function->WriteBody(buffer); |
| } |
| FixupSection(buffer, start); |
| } |
| |
| // == emit data segments ===================================================== |
| if (data_segments_.size() > 0) { |
| size_t start = EmitSection(kDataSectionCode, buffer); |
| buffer.write_size(data_segments_.size()); |
| |
| for (auto segment : data_segments_) { |
| buffer.write_u8(0); // linear memory segment |
| buffer.write_u8(kExprI32Const); // initializer expression for dest |
| buffer.write_u32v(segment.dest); |
| buffer.write_u8(kExprEnd); |
| buffer.write_u32v(static_cast<uint32_t>(segment.data.size())); |
| buffer.write(&segment.data[0], segment.data.size()); |
| } |
| FixupSection(buffer, start); |
| } |
| |
| // == Emit names ============================================================= |
| if (has_names) { |
| // Emit the section code. |
| buffer.write_u8(kUnknownSectionCode); |
| // Emit a placeholder for the length. |
| size_t start = buffer.reserve_u32v(); |
| // Emit the section string. |
| buffer.write_size(4); |
| buffer.write(reinterpret_cast<const byte*>("name"), 4); |
| // Emit the names. |
| buffer.write_size(functions_.size()); |
| for (auto function : functions_) { |
| buffer.write_size(function->name_.size()); |
| if (function->name_.size() > 0) { |
| buffer.write(reinterpret_cast<const byte*>(&function->name_[0]), |
| function->name_.size()); |
| } |
| buffer.write_u8(0); |
| } |
| FixupSection(buffer, start); |
| } |
| } |
| } // namespace wasm |
| } // namespace internal |
| } // namespace v8 |