| // 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/bit-vector.h" |
| #include "src/flags.h" |
| #include "src/handles.h" |
| #include "src/zone/zone-containers.h" |
| |
| #include "src/wasm/decoder.h" |
| #include "src/wasm/function-body-decoder.h" |
| #include "src/wasm/wasm-module.h" |
| #include "src/wasm/wasm-opcodes.h" |
| |
| #include "src/ostreams.h" |
| |
| #include "src/compiler/wasm-compiler.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace wasm { |
| |
| #if DEBUG |
| #define TRACE(...) \ |
| do { \ |
| if (FLAG_trace_wasm_decoder) PrintF(__VA_ARGS__); \ |
| } while (false) |
| #else |
| #define TRACE(...) |
| #endif |
| |
| #define CHECK_PROTOTYPE_OPCODE(flag) \ |
| if (module_ && module_->module->origin == kAsmJsOrigin) { \ |
| error("Opcode not supported for asmjs modules"); \ |
| } \ |
| if (!FLAG_##flag) { \ |
| error("Invalid opcode (enable with --" #flag ")"); \ |
| break; \ |
| } |
| // TODO(titzer): this is only for intermediate migration. |
| #define IMPLICIT_FUNCTION_END 1 |
| |
| // An SsaEnv environment carries the current local variable renaming |
| // as well as the current effect and control dependency in the TF graph. |
| // It maintains a control state that tracks whether the environment |
| // is reachable, has reached a control end, or has been merged. |
| struct SsaEnv { |
| enum State { kControlEnd, kUnreachable, kReached, kMerged }; |
| |
| State state; |
| TFNode* control; |
| TFNode* effect; |
| TFNode** locals; |
| |
| bool go() { return state >= kReached; } |
| void Kill(State new_state = kControlEnd) { |
| state = new_state; |
| locals = nullptr; |
| control = nullptr; |
| effect = nullptr; |
| } |
| void SetNotMerged() { |
| if (state == kMerged) state = kReached; |
| } |
| }; |
| |
| // An entry on the value stack. |
| struct Value { |
| const byte* pc; |
| TFNode* node; |
| ValueType type; |
| }; |
| |
| struct TryInfo : public ZoneObject { |
| SsaEnv* catch_env; |
| TFNode* exception; |
| |
| explicit TryInfo(SsaEnv* c) : catch_env(c), exception(nullptr) {} |
| }; |
| |
| struct MergeValues { |
| uint32_t arity; |
| union { |
| Value* array; |
| Value first; |
| } vals; // Either multiple values or a single value. |
| |
| Value& first() { |
| DCHECK_GT(arity, 0); |
| return arity == 1 ? vals.first : vals.array[0]; |
| } |
| }; |
| |
| static Value* NO_VALUE = nullptr; |
| |
| enum ControlKind { kControlIf, kControlBlock, kControlLoop, kControlTry }; |
| |
| // An entry on the control stack (i.e. if, block, loop). |
| struct Control { |
| const byte* pc; |
| ControlKind kind; |
| int stack_depth; // stack height at the beginning of the construct. |
| SsaEnv* end_env; // end environment for the construct. |
| SsaEnv* false_env; // false environment (only for if). |
| TryInfo* try_info; // Information used for compiling try statements. |
| int32_t previous_catch; // The previous Control (on the stack) with a catch. |
| |
| // Values merged into the end of this control construct. |
| MergeValues merge; |
| |
| inline bool is_if() const { return kind == kControlIf; } |
| inline bool is_block() const { return kind == kControlBlock; } |
| inline bool is_loop() const { return kind == kControlLoop; } |
| inline bool is_try() const { return kind == kControlTry; } |
| |
| // Named constructors. |
| static Control Block(const byte* pc, int stack_depth, SsaEnv* end_env, |
| int32_t previous_catch) { |
| return {pc, kControlBlock, stack_depth, end_env, |
| nullptr, nullptr, previous_catch, {0, {NO_VALUE}}}; |
| } |
| |
| static Control If(const byte* pc, int stack_depth, SsaEnv* end_env, |
| SsaEnv* false_env, int32_t previous_catch) { |
| return {pc, kControlIf, stack_depth, end_env, |
| false_env, nullptr, previous_catch, {0, {NO_VALUE}}}; |
| } |
| |
| static Control Loop(const byte* pc, int stack_depth, SsaEnv* end_env, |
| int32_t previous_catch) { |
| return {pc, kControlLoop, stack_depth, end_env, |
| nullptr, nullptr, previous_catch, {0, {NO_VALUE}}}; |
| } |
| |
| static Control Try(const byte* pc, int stack_depth, SsaEnv* end_env, |
| Zone* zone, SsaEnv* catch_env, int32_t previous_catch) { |
| DCHECK_NOT_NULL(catch_env); |
| TryInfo* try_info = new (zone) TryInfo(catch_env); |
| return {pc, kControlTry, stack_depth, end_env, |
| nullptr, try_info, previous_catch, {0, {NO_VALUE}}}; |
| } |
| }; |
| |
| // Macros that build nodes only if there is a graph and the current SSA |
| // environment is reachable from start. This avoids problems with malformed |
| // TF graphs when decoding inputs that have unreachable code. |
| #define BUILD(func, ...) \ |
| (build() ? CheckForException(builder_->func(__VA_ARGS__)) : nullptr) |
| #define BUILD0(func) (build() ? CheckForException(builder_->func()) : nullptr) |
| |
| struct LaneOperand { |
| uint8_t lane; |
| unsigned length; |
| |
| inline LaneOperand(Decoder* decoder, const byte* pc) { |
| lane = decoder->checked_read_u8(pc, 2, "lane"); |
| length = 1; |
| } |
| }; |
| |
| // Generic Wasm bytecode decoder with utilities for decoding operands, |
| // lengths, etc. |
| class WasmDecoder : public Decoder { |
| public: |
| WasmDecoder(ModuleEnv* module, FunctionSig* sig, const byte* start, |
| const byte* end) |
| : Decoder(start, end), |
| module_(module), |
| sig_(sig), |
| total_locals_(0), |
| local_types_(nullptr) {} |
| ModuleEnv* module_; |
| FunctionSig* sig_; |
| size_t total_locals_; |
| ZoneVector<ValueType>* local_types_; |
| |
| inline bool Validate(const byte* pc, LocalIndexOperand& operand) { |
| if (operand.index < total_locals_) { |
| if (local_types_) { |
| operand.type = local_types_->at(operand.index); |
| } else { |
| operand.type = kWasmStmt; |
| } |
| return true; |
| } |
| error(pc, pc + 1, "invalid local index: %u", operand.index); |
| return false; |
| } |
| |
| inline bool Validate(const byte* pc, GlobalIndexOperand& operand) { |
| ModuleEnv* m = module_; |
| if (m && m->module && operand.index < m->module->globals.size()) { |
| operand.global = &m->module->globals[operand.index]; |
| operand.type = operand.global->type; |
| return true; |
| } |
| error(pc, pc + 1, "invalid global index: %u", operand.index); |
| return false; |
| } |
| |
| inline bool Complete(const byte* pc, CallFunctionOperand& operand) { |
| ModuleEnv* m = module_; |
| if (m && m->module && operand.index < m->module->functions.size()) { |
| operand.sig = m->module->functions[operand.index].sig; |
| return true; |
| } |
| return false; |
| } |
| |
| inline bool Validate(const byte* pc, CallFunctionOperand& operand) { |
| if (Complete(pc, operand)) { |
| return true; |
| } |
| error(pc, pc + 1, "invalid function index: %u", operand.index); |
| return false; |
| } |
| |
| inline bool Complete(const byte* pc, CallIndirectOperand& operand) { |
| ModuleEnv* m = module_; |
| if (m && m->module && operand.index < m->module->signatures.size()) { |
| operand.sig = m->module->signatures[operand.index]; |
| return true; |
| } |
| return false; |
| } |
| |
| inline bool Validate(const byte* pc, CallIndirectOperand& operand) { |
| uint32_t table_index = 0; |
| if (!module_->IsValidTable(table_index)) { |
| error("function table has to exist to execute call_indirect"); |
| return false; |
| } |
| if (Complete(pc, operand)) { |
| return true; |
| } |
| error(pc, pc + 1, "invalid signature index: #%u", operand.index); |
| return false; |
| } |
| |
| inline bool Validate(const byte* pc, BreakDepthOperand& operand, |
| ZoneVector<Control>& control) { |
| if (operand.depth < control.size()) { |
| operand.target = &control[control.size() - operand.depth - 1]; |
| return true; |
| } |
| error(pc, pc + 1, "invalid break depth: %u", operand.depth); |
| return false; |
| } |
| |
| bool Validate(const byte* pc, BranchTableOperand& operand, |
| size_t block_depth) { |
| // TODO(titzer): add extra redundant validation for br_table here? |
| return true; |
| } |
| |
| inline bool Validate(const byte* pc, LaneOperand& operand) { |
| if (operand.lane < 0 || operand.lane > 3) { |
| error(pc_, pc_ + 2, "invalid extract lane value"); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| unsigned OpcodeLength(const byte* pc) { |
| switch (static_cast<byte>(*pc)) { |
| #define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name: |
| FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| #undef DECLARE_OPCODE_CASE |
| { |
| MemoryAccessOperand operand(this, pc, UINT32_MAX); |
| return 1 + operand.length; |
| } |
| case kExprBr: |
| case kExprBrIf: { |
| BreakDepthOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| case kExprSetGlobal: |
| case kExprGetGlobal: { |
| GlobalIndexOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| |
| case kExprCallFunction: { |
| CallFunctionOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| case kExprCallIndirect: { |
| CallIndirectOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| |
| case kExprTry: |
| case kExprIf: // fall thru |
| case kExprLoop: |
| case kExprBlock: { |
| BlockTypeOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| |
| case kExprSetLocal: |
| case kExprTeeLocal: |
| case kExprGetLocal: |
| case kExprCatch: { |
| LocalIndexOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| case kExprBrTable: { |
| BranchTableOperand operand(this, pc); |
| BranchTableIterator iterator(this, operand); |
| return 1 + iterator.length(); |
| } |
| case kExprI32Const: { |
| ImmI32Operand operand(this, pc); |
| return 1 + operand.length; |
| } |
| case kExprI64Const: { |
| ImmI64Operand operand(this, pc); |
| return 1 + operand.length; |
| } |
| case kExprGrowMemory: |
| case kExprMemorySize: { |
| MemoryIndexOperand operand(this, pc); |
| return 1 + operand.length; |
| } |
| case kExprI8Const: |
| return 2; |
| case kExprF32Const: |
| return 5; |
| case kExprF64Const: |
| return 9; |
| case kSimdPrefix: { |
| byte simd_index = checked_read_u8(pc, 1, "simd_index"); |
| WasmOpcode opcode = |
| static_cast<WasmOpcode>(kSimdPrefix << 8 | simd_index); |
| switch (opcode) { |
| #define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name: |
| FOREACH_SIMD_0_OPERAND_OPCODE(DECLARE_OPCODE_CASE) |
| #undef DECLARE_OPCODE_CASE |
| { |
| return 2; |
| } |
| #define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name: |
| FOREACH_SIMD_1_OPERAND_OPCODE(DECLARE_OPCODE_CASE) |
| #undef DECLARE_OPCODE_CASE |
| { |
| return 3; |
| } |
| default: |
| error("invalid SIMD opcode"); |
| return 2; |
| } |
| } |
| default: |
| return 1; |
| } |
| } |
| }; |
| |
| static const int32_t kNullCatch = -1; |
| |
| // The full WASM decoder for bytecode. Both verifies bytecode and generates |
| // a TurboFan IR graph. |
| class WasmFullDecoder : public WasmDecoder { |
| public: |
| WasmFullDecoder(Zone* zone, TFBuilder* builder, const FunctionBody& body) |
| : WasmDecoder(body.module, body.sig, body.start, body.end), |
| zone_(zone), |
| builder_(builder), |
| base_(body.base), |
| local_type_vec_(zone), |
| stack_(zone), |
| control_(zone), |
| last_end_found_(false), |
| current_catch_(kNullCatch) { |
| local_types_ = &local_type_vec_; |
| } |
| |
| bool Decode() { |
| if (FLAG_wasm_code_fuzzer_gen_test) { |
| PrintWasmCodeForDebugging(start_, end_); |
| } |
| base::ElapsedTimer decode_timer; |
| if (FLAG_trace_wasm_decode_time) { |
| decode_timer.Start(); |
| } |
| stack_.clear(); |
| control_.clear(); |
| |
| if (end_ < pc_) { |
| error("function body end < start"); |
| return false; |
| } |
| |
| DecodeLocalDecls(); |
| InitSsaEnv(); |
| DecodeFunctionBody(); |
| |
| if (failed()) return TraceFailed(); |
| |
| #if IMPLICIT_FUNCTION_END |
| // With implicit end support (old style), the function block |
| // remains on the stack. Other control blocks are an error. |
| if (control_.size() > 1) { |
| error(pc_, control_.back().pc, "unterminated control structure"); |
| return TraceFailed(); |
| } |
| |
| // Assume an implicit end to the function body block. |
| if (control_.size() == 1) { |
| Control* c = &control_.back(); |
| if (ssa_env_->go()) { |
| FallThruTo(c); |
| } |
| |
| if (c->end_env->go()) { |
| // Push the end values onto the stack. |
| stack_.resize(c->stack_depth); |
| if (c->merge.arity == 1) { |
| stack_.push_back(c->merge.vals.first); |
| } else { |
| for (unsigned i = 0; i < c->merge.arity; i++) { |
| stack_.push_back(c->merge.vals.array[i]); |
| } |
| } |
| |
| TRACE(" @%-8d #xx:%-20s|", startrel(pc_), "ImplicitReturn"); |
| SetEnv("function:end", c->end_env); |
| DoReturn(); |
| TRACE("\n"); |
| } |
| } |
| #else |
| if (!control_.empty()) { |
| error(pc_, control_.back().pc, "unterminated control structure"); |
| return TraceFailed(); |
| } |
| |
| if (!last_end_found_) { |
| error("function body must end with \"end\" opcode."); |
| return false; |
| } |
| #endif |
| |
| if (FLAG_trace_wasm_decode_time) { |
| double ms = decode_timer.Elapsed().InMillisecondsF(); |
| PrintF("wasm-decode %s (%0.3f ms)\n\n", ok() ? "ok" : "failed", ms); |
| } else { |
| TRACE("wasm-decode %s\n\n", ok() ? "ok" : "failed"); |
| } |
| |
| return true; |
| } |
| |
| bool TraceFailed() { |
| TRACE("wasm-error module+%-6d func+%d: %s\n\n", baserel(error_pc_), |
| startrel(error_pc_), error_msg_.get()); |
| return false; |
| } |
| |
| bool DecodeLocalDecls(BodyLocalDecls& decls) { |
| DecodeLocalDecls(); |
| if (failed()) return false; |
| decls.decls_encoded_size = pc_offset(); |
| decls.local_types.reserve(local_type_vec_.size()); |
| for (size_t pos = 0; pos < local_type_vec_.size();) { |
| uint32_t count = 0; |
| ValueType type = local_type_vec_[pos]; |
| while (pos < local_type_vec_.size() && local_type_vec_[pos] == type) { |
| pos++; |
| count++; |
| } |
| decls.local_types.push_back(std::pair<ValueType, uint32_t>(type, count)); |
| } |
| decls.total_local_count = static_cast<uint32_t>(local_type_vec_.size()); |
| return true; |
| } |
| |
| BitVector* AnalyzeLoopAssignmentForTesting(const byte* pc, |
| size_t num_locals) { |
| total_locals_ = num_locals; |
| local_type_vec_.reserve(num_locals); |
| if (num_locals > local_type_vec_.size()) { |
| local_type_vec_.insert(local_type_vec_.end(), |
| num_locals - local_type_vec_.size(), kWasmI32); |
| } |
| return AnalyzeLoopAssignment(pc); |
| } |
| |
| private: |
| static const size_t kErrorMsgSize = 128; |
| |
| Zone* zone_; |
| TFBuilder* builder_; |
| const byte* base_; |
| |
| SsaEnv* ssa_env_; |
| |
| ZoneVector<ValueType> local_type_vec_; // types of local variables. |
| ZoneVector<Value> stack_; // stack of values. |
| ZoneVector<Control> control_; // stack of blocks, loops, and ifs. |
| bool last_end_found_; |
| |
| int32_t current_catch_; |
| |
| TryInfo* current_try_info() { return control_[current_catch_].try_info; } |
| |
| inline bool build() { return builder_ && ssa_env_->go(); } |
| |
| void InitSsaEnv() { |
| TFNode* start = nullptr; |
| SsaEnv* ssa_env = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| size_t size = sizeof(TFNode*) * EnvironmentCount(); |
| ssa_env->state = SsaEnv::kReached; |
| ssa_env->locals = |
| size > 0 ? reinterpret_cast<TFNode**>(zone_->New(size)) : nullptr; |
| |
| if (builder_) { |
| start = builder_->Start(static_cast<int>(sig_->parameter_count() + 1)); |
| // Initialize local variables. |
| uint32_t index = 0; |
| while (index < sig_->parameter_count()) { |
| ssa_env->locals[index] = builder_->Param(index); |
| index++; |
| } |
| while (index < local_type_vec_.size()) { |
| ValueType type = local_type_vec_[index]; |
| TFNode* node = DefaultValue(type); |
| while (index < local_type_vec_.size() && |
| local_type_vec_[index] == type) { |
| // Do a whole run of like-typed locals at a time. |
| ssa_env->locals[index++] = node; |
| } |
| } |
| builder_->set_module(module_); |
| } |
| ssa_env->control = start; |
| ssa_env->effect = start; |
| SetEnv("initial", ssa_env); |
| if (builder_) { |
| builder_->StackCheck(position()); |
| } |
| } |
| |
| TFNode* DefaultValue(ValueType type) { |
| switch (type) { |
| case kWasmI32: |
| return builder_->Int32Constant(0); |
| case kWasmI64: |
| return builder_->Int64Constant(0); |
| case kWasmF32: |
| return builder_->Float32Constant(0); |
| case kWasmF64: |
| return builder_->Float64Constant(0); |
| case kWasmS128: |
| return builder_->CreateS128Value(0); |
| default: |
| UNREACHABLE(); |
| return nullptr; |
| } |
| } |
| |
| char* indentation() { |
| static const int kMaxIndent = 64; |
| static char bytes[kMaxIndent + 1]; |
| for (int i = 0; i < kMaxIndent; ++i) bytes[i] = ' '; |
| bytes[kMaxIndent] = 0; |
| if (stack_.size() < kMaxIndent / 2) { |
| bytes[stack_.size() * 2] = 0; |
| } |
| return bytes; |
| } |
| |
| // Decodes the locals declarations, if any, populating {local_type_vec_}. |
| void DecodeLocalDecls() { |
| DCHECK_EQ(0, local_type_vec_.size()); |
| // Initialize {local_type_vec} from signature. |
| if (sig_) { |
| local_type_vec_.reserve(sig_->parameter_count()); |
| for (size_t i = 0; i < sig_->parameter_count(); ++i) { |
| local_type_vec_.push_back(sig_->GetParam(i)); |
| } |
| } |
| // Decode local declarations, if any. |
| uint32_t entries = consume_u32v("local decls count"); |
| TRACE("local decls count: %u\n", entries); |
| while (entries-- > 0 && pc_ < limit_) { |
| uint32_t count = consume_u32v("local count"); |
| if ((count + local_type_vec_.size()) > kMaxNumWasmLocals) { |
| error(pc_ - 1, "local count too large"); |
| return; |
| } |
| byte code = consume_u8("local type"); |
| ValueType type; |
| switch (code) { |
| case kLocalI32: |
| type = kWasmI32; |
| break; |
| case kLocalI64: |
| type = kWasmI64; |
| break; |
| case kLocalF32: |
| type = kWasmF32; |
| break; |
| case kLocalF64: |
| type = kWasmF64; |
| break; |
| case kLocalS128: |
| type = kWasmS128; |
| break; |
| default: |
| error(pc_ - 1, "invalid local type"); |
| return; |
| } |
| local_type_vec_.insert(local_type_vec_.end(), count, type); |
| } |
| total_locals_ = local_type_vec_.size(); |
| } |
| |
| // Decodes the body of a function. |
| void DecodeFunctionBody() { |
| TRACE("wasm-decode %p...%p (module+%d, %d bytes) %s\n", |
| reinterpret_cast<const void*>(start_), |
| reinterpret_cast<const void*>(limit_), baserel(pc_), |
| static_cast<int>(limit_ - start_), builder_ ? "graph building" : ""); |
| |
| { |
| // Set up initial function block. |
| SsaEnv* break_env = ssa_env_; |
| SetEnv("initial env", Steal(break_env)); |
| PushBlock(break_env); |
| Control* c = &control_.back(); |
| c->merge.arity = static_cast<uint32_t>(sig_->return_count()); |
| |
| if (c->merge.arity == 1) { |
| c->merge.vals.first = {pc_, nullptr, sig_->GetReturn(0)}; |
| } else if (c->merge.arity > 1) { |
| c->merge.vals.array = zone_->NewArray<Value>(c->merge.arity); |
| for (unsigned i = 0; i < c->merge.arity; i++) { |
| c->merge.vals.array[i] = {pc_, nullptr, sig_->GetReturn(i)}; |
| } |
| } |
| } |
| |
| if (pc_ >= limit_) return; // Nothing to do. |
| |
| while (true) { // decoding loop. |
| unsigned len = 1; |
| WasmOpcode opcode = static_cast<WasmOpcode>(*pc_); |
| if (!WasmOpcodes::IsPrefixOpcode(opcode)) { |
| TRACE(" @%-8d #%02x:%-20s|", startrel(pc_), opcode, |
| WasmOpcodes::ShortOpcodeName(opcode)); |
| } |
| |
| FunctionSig* sig = WasmOpcodes::Signature(opcode); |
| if (sig) { |
| BuildSimpleOperator(opcode, sig); |
| } else { |
| // Complex bytecode. |
| switch (opcode) { |
| case kExprNop: |
| break; |
| case kExprBlock: { |
| // The break environment is the outer environment. |
| BlockTypeOperand operand(this, pc_); |
| SsaEnv* break_env = ssa_env_; |
| PushBlock(break_env); |
| SetEnv("block:start", Steal(break_env)); |
| SetBlockType(&control_.back(), operand); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprThrow: { |
| CHECK_PROTOTYPE_OPCODE(wasm_eh_prototype); |
| Value value = Pop(0, kWasmI32); |
| BUILD(Throw, value.node); |
| break; |
| } |
| case kExprTry: { |
| CHECK_PROTOTYPE_OPCODE(wasm_eh_prototype); |
| BlockTypeOperand operand(this, pc_); |
| SsaEnv* outer_env = ssa_env_; |
| SsaEnv* try_env = Steal(outer_env); |
| SsaEnv* catch_env = UnreachableEnv(); |
| PushTry(outer_env, catch_env); |
| SetEnv("try_catch:start", try_env); |
| SetBlockType(&control_.back(), operand); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprCatch: { |
| CHECK_PROTOTYPE_OPCODE(wasm_eh_prototype); |
| LocalIndexOperand operand(this, pc_); |
| len = 1 + operand.length; |
| |
| if (control_.empty()) { |
| error("catch does not match any try"); |
| break; |
| } |
| |
| Control* c = &control_.back(); |
| if (!c->is_try()) { |
| error("catch does not match any try"); |
| break; |
| } |
| |
| if (c->try_info->catch_env == nullptr) { |
| error(pc_, "catch already present for try with catch"); |
| break; |
| } |
| |
| if (ssa_env_->go()) { |
| MergeValuesInto(c); |
| } |
| stack_.resize(c->stack_depth); |
| |
| DCHECK_NOT_NULL(c->try_info); |
| SsaEnv* catch_env = c->try_info->catch_env; |
| c->try_info->catch_env = nullptr; |
| SetEnv("catch:begin", catch_env); |
| current_catch_ = c->previous_catch; |
| |
| if (Validate(pc_, operand)) { |
| if (ssa_env_->locals) { |
| TFNode* exception_as_i32 = |
| BUILD(Catch, c->try_info->exception, position()); |
| ssa_env_->locals[operand.index] = exception_as_i32; |
| } |
| } |
| |
| break; |
| } |
| case kExprLoop: { |
| BlockTypeOperand operand(this, pc_); |
| SsaEnv* finish_try_env = Steal(ssa_env_); |
| // The continue environment is the inner environment. |
| SsaEnv* loop_body_env = PrepareForLoop(pc_, finish_try_env); |
| SetEnv("loop:start", loop_body_env); |
| ssa_env_->SetNotMerged(); |
| PushLoop(finish_try_env); |
| SetBlockType(&control_.back(), operand); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprIf: { |
| // Condition on top of stack. Split environments for branches. |
| BlockTypeOperand operand(this, pc_); |
| Value cond = Pop(0, kWasmI32); |
| TFNode* if_true = nullptr; |
| TFNode* if_false = nullptr; |
| BUILD(BranchNoHint, cond.node, &if_true, &if_false); |
| SsaEnv* end_env = ssa_env_; |
| SsaEnv* false_env = Split(ssa_env_); |
| false_env->control = if_false; |
| SsaEnv* true_env = Steal(ssa_env_); |
| true_env->control = if_true; |
| PushIf(end_env, false_env); |
| SetEnv("if:true", true_env); |
| SetBlockType(&control_.back(), operand); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprElse: { |
| if (control_.empty()) { |
| error("else does not match any if"); |
| break; |
| } |
| Control* c = &control_.back(); |
| if (!c->is_if()) { |
| error(pc_, c->pc, "else does not match an if"); |
| break; |
| } |
| if (c->false_env == nullptr) { |
| error(pc_, c->pc, "else already present for if"); |
| break; |
| } |
| FallThruTo(c); |
| // Switch to environment for false branch. |
| stack_.resize(c->stack_depth); |
| SetEnv("if_else:false", c->false_env); |
| c->false_env = nullptr; // record that an else is already seen |
| break; |
| } |
| case kExprEnd: { |
| if (control_.empty()) { |
| error("end does not match any if, try, or block"); |
| return; |
| } |
| const char* name = "block:end"; |
| Control* c = &control_.back(); |
| if (c->is_loop()) { |
| // A loop just leaves the values on the stack. |
| TypeCheckLoopFallThru(c); |
| PopControl(); |
| SetEnv("loop:end", ssa_env_); |
| break; |
| } |
| if (c->is_if()) { |
| if (c->false_env != nullptr) { |
| // End the true branch of a one-armed if. |
| Goto(c->false_env, c->end_env); |
| if (ssa_env_->go() && |
| static_cast<int>(stack_.size()) != c->stack_depth) { |
| error("end of if expected empty stack"); |
| stack_.resize(c->stack_depth); |
| } |
| if (c->merge.arity > 0) { |
| error("non-void one-armed if"); |
| } |
| name = "if:merge"; |
| } else { |
| // End the false branch of a two-armed if. |
| name = "if_else:merge"; |
| } |
| } else if (c->is_try()) { |
| name = "try:end"; |
| |
| // validate that catch was seen. |
| if (c->try_info->catch_env != nullptr) { |
| error(pc_, "missing catch in try"); |
| break; |
| } |
| } |
| FallThruTo(c); |
| SetEnv(name, c->end_env); |
| |
| // Push the end values onto the stack. |
| stack_.resize(c->stack_depth); |
| if (c->merge.arity == 1) { |
| stack_.push_back(c->merge.vals.first); |
| } else { |
| for (unsigned i = 0; i < c->merge.arity; i++) { |
| stack_.push_back(c->merge.vals.array[i]); |
| } |
| } |
| |
| PopControl(); |
| |
| if (control_.empty()) { |
| // If the last (implicit) control was popped, check we are at end. |
| if (pc_ + 1 != end_) { |
| error(pc_, pc_ + 1, "trailing code after function end"); |
| } |
| last_end_found_ = true; |
| if (ssa_env_->go()) { |
| // The result of the block is the return value. |
| TRACE(" @%-8d #xx:%-20s|", startrel(pc_), "ImplicitReturn"); |
| DoReturn(); |
| TRACE("\n"); |
| } |
| return; |
| } |
| break; |
| } |
| case kExprSelect: { |
| Value cond = Pop(2, kWasmI32); |
| Value fval = Pop(); |
| Value tval = Pop(); |
| if (tval.type == kWasmStmt || tval.type != fval.type) { |
| if (tval.type != kWasmEnd && fval.type != kWasmEnd) { |
| error("type mismatch in select"); |
| break; |
| } |
| } |
| if (build()) { |
| DCHECK(tval.type != kWasmEnd); |
| DCHECK(fval.type != kWasmEnd); |
| DCHECK(cond.type != kWasmEnd); |
| TFNode* controls[2]; |
| builder_->BranchNoHint(cond.node, &controls[0], &controls[1]); |
| TFNode* merge = builder_->Merge(2, controls); |
| TFNode* vals[2] = {tval.node, fval.node}; |
| TFNode* phi = builder_->Phi(tval.type, 2, vals, merge); |
| Push(tval.type, phi); |
| ssa_env_->control = merge; |
| } else { |
| Push(tval.type, nullptr); |
| } |
| break; |
| } |
| case kExprBr: { |
| BreakDepthOperand operand(this, pc_); |
| if (Validate(pc_, operand, control_)) { |
| BreakTo(operand.depth); |
| } |
| len = 1 + operand.length; |
| EndControl(); |
| break; |
| } |
| case kExprBrIf: { |
| BreakDepthOperand operand(this, pc_); |
| Value cond = Pop(0, kWasmI32); |
| if (ok() && Validate(pc_, operand, control_)) { |
| SsaEnv* fenv = ssa_env_; |
| SsaEnv* tenv = Split(fenv); |
| fenv->SetNotMerged(); |
| BUILD(BranchNoHint, cond.node, &tenv->control, &fenv->control); |
| ssa_env_ = tenv; |
| BreakTo(operand.depth); |
| ssa_env_ = fenv; |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprBrTable: { |
| BranchTableOperand operand(this, pc_); |
| BranchTableIterator iterator(this, operand); |
| if (Validate(pc_, operand, control_.size())) { |
| Value key = Pop(0, kWasmI32); |
| if (failed()) break; |
| |
| SsaEnv* break_env = ssa_env_; |
| if (operand.table_count > 0) { |
| // Build branches to the various blocks based on the table. |
| TFNode* sw = BUILD(Switch, operand.table_count + 1, key.node); |
| |
| SsaEnv* copy = Steal(break_env); |
| ssa_env_ = copy; |
| while (ok() && iterator.has_next()) { |
| uint32_t i = iterator.cur_index(); |
| const byte* pos = iterator.pc(); |
| uint32_t target = iterator.next(); |
| if (target >= control_.size()) { |
| error(pos, "improper branch in br_table"); |
| break; |
| } |
| ssa_env_ = Split(copy); |
| ssa_env_->control = (i == operand.table_count) |
| ? BUILD(IfDefault, sw) |
| : BUILD(IfValue, i, sw); |
| BreakTo(target); |
| } |
| if (failed()) break; |
| } else { |
| // Only a default target. Do the equivalent of br. |
| const byte* pos = iterator.pc(); |
| uint32_t target = iterator.next(); |
| if (target >= control_.size()) { |
| error(pos, "improper branch in br_table"); |
| break; |
| } |
| BreakTo(target); |
| } |
| // br_table ends the control flow like br. |
| ssa_env_ = break_env; |
| } |
| len = 1 + iterator.length(); |
| break; |
| } |
| case kExprReturn: { |
| DoReturn(); |
| break; |
| } |
| case kExprUnreachable: { |
| BUILD(Unreachable, position()); |
| EndControl(); |
| break; |
| } |
| case kExprI8Const: { |
| ImmI8Operand operand(this, pc_); |
| Push(kWasmI32, BUILD(Int32Constant, operand.value)); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprI32Const: { |
| ImmI32Operand operand(this, pc_); |
| Push(kWasmI32, BUILD(Int32Constant, operand.value)); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprI64Const: { |
| ImmI64Operand operand(this, pc_); |
| Push(kWasmI64, BUILD(Int64Constant, operand.value)); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprF32Const: { |
| ImmF32Operand operand(this, pc_); |
| Push(kWasmF32, BUILD(Float32Constant, operand.value)); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprF64Const: { |
| ImmF64Operand operand(this, pc_); |
| Push(kWasmF64, BUILD(Float64Constant, operand.value)); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprGetLocal: { |
| LocalIndexOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| if (build()) { |
| Push(operand.type, ssa_env_->locals[operand.index]); |
| } else { |
| Push(operand.type, nullptr); |
| } |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprSetLocal: { |
| LocalIndexOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| Value val = Pop(0, local_type_vec_[operand.index]); |
| if (ssa_env_->locals) ssa_env_->locals[operand.index] = val.node; |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprTeeLocal: { |
| LocalIndexOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| Value val = Pop(0, local_type_vec_[operand.index]); |
| if (ssa_env_->locals) ssa_env_->locals[operand.index] = val.node; |
| Push(val.type, val.node); |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprDrop: { |
| Pop(); |
| break; |
| } |
| case kExprGetGlobal: { |
| GlobalIndexOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| Push(operand.type, BUILD(GetGlobal, operand.index)); |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprSetGlobal: { |
| GlobalIndexOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| if (operand.global->mutability) { |
| Value val = Pop(0, operand.type); |
| BUILD(SetGlobal, operand.index, val.node); |
| } else { |
| error(pc_, pc_ + 1, "immutable global #%u cannot be assigned", |
| operand.index); |
| } |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprI32LoadMem8S: |
| len = DecodeLoadMem(kWasmI32, MachineType::Int8()); |
| break; |
| case kExprI32LoadMem8U: |
| len = DecodeLoadMem(kWasmI32, MachineType::Uint8()); |
| break; |
| case kExprI32LoadMem16S: |
| len = DecodeLoadMem(kWasmI32, MachineType::Int16()); |
| break; |
| case kExprI32LoadMem16U: |
| len = DecodeLoadMem(kWasmI32, MachineType::Uint16()); |
| break; |
| case kExprI32LoadMem: |
| len = DecodeLoadMem(kWasmI32, MachineType::Int32()); |
| break; |
| case kExprI64LoadMem8S: |
| len = DecodeLoadMem(kWasmI64, MachineType::Int8()); |
| break; |
| case kExprI64LoadMem8U: |
| len = DecodeLoadMem(kWasmI64, MachineType::Uint8()); |
| break; |
| case kExprI64LoadMem16S: |
| len = DecodeLoadMem(kWasmI64, MachineType::Int16()); |
| break; |
| case kExprI64LoadMem16U: |
| len = DecodeLoadMem(kWasmI64, MachineType::Uint16()); |
| break; |
| case kExprI64LoadMem32S: |
| len = DecodeLoadMem(kWasmI64, MachineType::Int32()); |
| break; |
| case kExprI64LoadMem32U: |
| len = DecodeLoadMem(kWasmI64, MachineType::Uint32()); |
| break; |
| case kExprI64LoadMem: |
| len = DecodeLoadMem(kWasmI64, MachineType::Int64()); |
| break; |
| case kExprF32LoadMem: |
| len = DecodeLoadMem(kWasmF32, MachineType::Float32()); |
| break; |
| case kExprF64LoadMem: |
| len = DecodeLoadMem(kWasmF64, MachineType::Float64()); |
| break; |
| case kExprI32StoreMem8: |
| len = DecodeStoreMem(kWasmI32, MachineType::Int8()); |
| break; |
| case kExprI32StoreMem16: |
| len = DecodeStoreMem(kWasmI32, MachineType::Int16()); |
| break; |
| case kExprI32StoreMem: |
| len = DecodeStoreMem(kWasmI32, MachineType::Int32()); |
| break; |
| case kExprI64StoreMem8: |
| len = DecodeStoreMem(kWasmI64, MachineType::Int8()); |
| break; |
| case kExprI64StoreMem16: |
| len = DecodeStoreMem(kWasmI64, MachineType::Int16()); |
| break; |
| case kExprI64StoreMem32: |
| len = DecodeStoreMem(kWasmI64, MachineType::Int32()); |
| break; |
| case kExprI64StoreMem: |
| len = DecodeStoreMem(kWasmI64, MachineType::Int64()); |
| break; |
| case kExprF32StoreMem: |
| len = DecodeStoreMem(kWasmF32, MachineType::Float32()); |
| break; |
| case kExprF64StoreMem: |
| len = DecodeStoreMem(kWasmF64, MachineType::Float64()); |
| break; |
| case kExprGrowMemory: { |
| MemoryIndexOperand operand(this, pc_); |
| if (module_->module->origin != kAsmJsOrigin) { |
| Value val = Pop(0, kWasmI32); |
| Push(kWasmI32, BUILD(GrowMemory, val.node)); |
| } else { |
| error("grow_memory is not supported for asmjs modules"); |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprMemorySize: { |
| MemoryIndexOperand operand(this, pc_); |
| Push(kWasmI32, BUILD(CurrentMemoryPages)); |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprCallFunction: { |
| CallFunctionOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| TFNode** buffer = PopArgs(operand.sig); |
| TFNode** rets = nullptr; |
| BUILD(CallDirect, operand.index, buffer, &rets, position()); |
| PushReturns(operand.sig, rets); |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kExprCallIndirect: { |
| CallIndirectOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| Value index = Pop(0, kWasmI32); |
| TFNode** buffer = PopArgs(operand.sig); |
| if (buffer) buffer[0] = index.node; |
| TFNode** rets = nullptr; |
| BUILD(CallIndirect, operand.index, buffer, &rets, position()); |
| PushReturns(operand.sig, rets); |
| } |
| len = 1 + operand.length; |
| break; |
| } |
| case kSimdPrefix: { |
| CHECK_PROTOTYPE_OPCODE(wasm_simd_prototype); |
| len++; |
| byte simd_index = checked_read_u8(pc_, 1, "simd index"); |
| opcode = static_cast<WasmOpcode>(opcode << 8 | simd_index); |
| TRACE(" @%-4d #%02x #%02x:%-20s|", startrel(pc_), kSimdPrefix, |
| simd_index, WasmOpcodes::ShortOpcodeName(opcode)); |
| len += DecodeSimdOpcode(opcode); |
| break; |
| } |
| case kAtomicPrefix: { |
| if (!module_ || module_->module->origin != kAsmJsOrigin) { |
| error("Atomics are allowed only in AsmJs modules"); |
| break; |
| } |
| if (!FLAG_wasm_atomics_prototype) { |
| error("Invalid opcode (enable with --wasm_atomics_prototype)"); |
| break; |
| } |
| len = 2; |
| byte atomic_opcode = checked_read_u8(pc_, 1, "atomic index"); |
| opcode = static_cast<WasmOpcode>(opcode << 8 | atomic_opcode); |
| sig = WasmOpcodes::AtomicSignature(opcode); |
| if (sig) { |
| BuildAtomicOperator(opcode); |
| } |
| break; |
| } |
| default: { |
| // Deal with special asmjs opcodes. |
| if (module_ && module_->module->origin == kAsmJsOrigin) { |
| sig = WasmOpcodes::AsmjsSignature(opcode); |
| if (sig) { |
| BuildSimpleOperator(opcode, sig); |
| } |
| } else { |
| error("Invalid opcode"); |
| return; |
| } |
| } |
| } |
| } |
| |
| #if DEBUG |
| if (FLAG_trace_wasm_decoder) { |
| for (size_t i = 0; i < stack_.size(); ++i) { |
| Value& val = stack_[i]; |
| WasmOpcode opcode = static_cast<WasmOpcode>(*val.pc); |
| if (WasmOpcodes::IsPrefixOpcode(opcode)) { |
| opcode = static_cast<WasmOpcode>(opcode << 8 | *(val.pc + 1)); |
| } |
| PrintF(" %c@%d:%s", WasmOpcodes::ShortNameOf(val.type), |
| static_cast<int>(val.pc - start_), |
| WasmOpcodes::ShortOpcodeName(opcode)); |
| switch (opcode) { |
| case kExprI32Const: { |
| ImmI32Operand operand(this, val.pc); |
| PrintF("[%d]", operand.value); |
| break; |
| } |
| case kExprGetLocal: { |
| LocalIndexOperand operand(this, val.pc); |
| PrintF("[%u]", operand.index); |
| break; |
| } |
| case kExprSetLocal: // fallthru |
| case kExprTeeLocal: { |
| LocalIndexOperand operand(this, val.pc); |
| PrintF("[%u]", operand.index); |
| break; |
| } |
| default: |
| break; |
| } |
| } |
| PrintF("\n"); |
| } |
| #endif |
| pc_ += len; |
| if (pc_ >= limit_) { |
| // End of code reached or exceeded. |
| if (pc_ > limit_ && ok()) error("Beyond end of code"); |
| return; |
| } |
| } // end decode loop |
| } |
| |
| void EndControl() { ssa_env_->Kill(SsaEnv::kControlEnd); } |
| |
| void SetBlockType(Control* c, BlockTypeOperand& operand) { |
| c->merge.arity = operand.arity; |
| if (c->merge.arity == 1) { |
| c->merge.vals.first = {pc_, nullptr, operand.read_entry(0)}; |
| } else if (c->merge.arity > 1) { |
| c->merge.vals.array = zone_->NewArray<Value>(c->merge.arity); |
| for (unsigned i = 0; i < c->merge.arity; i++) { |
| c->merge.vals.array[i] = {pc_, nullptr, operand.read_entry(i)}; |
| } |
| } |
| } |
| |
| TFNode** PopArgs(FunctionSig* sig) { |
| if (build()) { |
| int count = static_cast<int>(sig->parameter_count()); |
| TFNode** buffer = builder_->Buffer(count + 1); |
| buffer[0] = nullptr; // reserved for code object or function index. |
| for (int i = count - 1; i >= 0; i--) { |
| buffer[i + 1] = Pop(i, sig->GetParam(i)).node; |
| } |
| return buffer; |
| } else { |
| int count = static_cast<int>(sig->parameter_count()); |
| for (int i = count - 1; i >= 0; i--) { |
| Pop(i, sig->GetParam(i)); |
| } |
| return nullptr; |
| } |
| } |
| |
| ValueType GetReturnType(FunctionSig* sig) { |
| return sig->return_count() == 0 ? kWasmStmt : sig->GetReturn(); |
| } |
| |
| void PushBlock(SsaEnv* end_env) { |
| const int stack_depth = static_cast<int>(stack_.size()); |
| control_.emplace_back( |
| Control::Block(pc_, stack_depth, end_env, current_catch_)); |
| } |
| |
| void PushLoop(SsaEnv* end_env) { |
| const int stack_depth = static_cast<int>(stack_.size()); |
| control_.emplace_back( |
| Control::Loop(pc_, stack_depth, end_env, current_catch_)); |
| } |
| |
| void PushIf(SsaEnv* end_env, SsaEnv* false_env) { |
| const int stack_depth = static_cast<int>(stack_.size()); |
| control_.emplace_back( |
| Control::If(pc_, stack_depth, end_env, false_env, current_catch_)); |
| } |
| |
| void PushTry(SsaEnv* end_env, SsaEnv* catch_env) { |
| const int stack_depth = static_cast<int>(stack_.size()); |
| control_.emplace_back(Control::Try(pc_, stack_depth, end_env, zone_, |
| catch_env, current_catch_)); |
| current_catch_ = static_cast<int32_t>(control_.size() - 1); |
| } |
| |
| void PopControl() { control_.pop_back(); } |
| |
| int DecodeLoadMem(ValueType type, MachineType mem_type) { |
| MemoryAccessOperand operand(this, pc_, |
| ElementSizeLog2Of(mem_type.representation())); |
| |
| Value index = Pop(0, kWasmI32); |
| TFNode* node = BUILD(LoadMem, type, mem_type, index.node, operand.offset, |
| operand.alignment, position()); |
| Push(type, node); |
| return 1 + operand.length; |
| } |
| |
| int DecodeStoreMem(ValueType type, MachineType mem_type) { |
| MemoryAccessOperand operand(this, pc_, |
| ElementSizeLog2Of(mem_type.representation())); |
| Value val = Pop(1, type); |
| Value index = Pop(0, kWasmI32); |
| BUILD(StoreMem, mem_type, index.node, operand.offset, operand.alignment, |
| val.node, position()); |
| return 1 + operand.length; |
| } |
| |
| unsigned ExtractLane(WasmOpcode opcode, ValueType type) { |
| LaneOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| compiler::NodeVector inputs(1, zone_); |
| inputs[0] = Pop(0, ValueType::kSimd128).node; |
| TFNode* node = BUILD(SimdLaneOp, opcode, operand.lane, inputs); |
| Push(type, node); |
| } |
| return operand.length; |
| } |
| |
| unsigned ReplaceLane(WasmOpcode opcode, ValueType type) { |
| LaneOperand operand(this, pc_); |
| if (Validate(pc_, operand)) { |
| compiler::NodeVector inputs(2, zone_); |
| inputs[1] = Pop(1, type).node; |
| inputs[0] = Pop(0, ValueType::kSimd128).node; |
| TFNode* node = BUILD(SimdLaneOp, opcode, operand.lane, inputs); |
| Push(ValueType::kSimd128, node); |
| } |
| return operand.length; |
| } |
| |
| unsigned DecodeSimdOpcode(WasmOpcode opcode) { |
| unsigned len = 0; |
| switch (opcode) { |
| case kExprI32x4ExtractLane: { |
| len = ExtractLane(opcode, ValueType::kWord32); |
| break; |
| } |
| case kExprF32x4ExtractLane: { |
| len = ExtractLane(opcode, ValueType::kFloat32); |
| break; |
| } |
| case kExprI32x4ReplaceLane: { |
| len = ReplaceLane(opcode, ValueType::kWord32); |
| break; |
| } |
| case kExprF32x4ReplaceLane: { |
| len = ReplaceLane(opcode, ValueType::kFloat32); |
| break; |
| } |
| default: { |
| FunctionSig* sig = WasmOpcodes::Signature(opcode); |
| if (sig != nullptr) { |
| compiler::NodeVector inputs(sig->parameter_count(), zone_); |
| for (size_t i = sig->parameter_count(); i > 0; i--) { |
| Value val = Pop(static_cast<int>(i - 1), sig->GetParam(i - 1)); |
| inputs[i - 1] = val.node; |
| } |
| TFNode* node = BUILD(SimdOp, opcode, inputs); |
| Push(GetReturnType(sig), node); |
| } else { |
| error("invalid simd opcode"); |
| } |
| } |
| } |
| return len; |
| } |
| |
| void BuildAtomicOperator(WasmOpcode opcode) { UNIMPLEMENTED(); } |
| |
| void DoReturn() { |
| int count = static_cast<int>(sig_->return_count()); |
| TFNode** buffer = nullptr; |
| if (build()) buffer = builder_->Buffer(count); |
| |
| // Pop return values off the stack in reverse order. |
| for (int i = count - 1; i >= 0; i--) { |
| Value val = Pop(i, sig_->GetReturn(i)); |
| if (buffer) buffer[i] = val.node; |
| } |
| |
| BUILD(Return, count, buffer); |
| EndControl(); |
| } |
| |
| void Push(ValueType type, TFNode* node) { |
| if (type != kWasmStmt && type != kWasmEnd) { |
| stack_.push_back({pc_, node, type}); |
| } |
| } |
| |
| void PushReturns(FunctionSig* sig, TFNode** rets) { |
| for (size_t i = 0; i < sig->return_count(); i++) { |
| // When verifying only, then {rets} will be null, so push null. |
| Push(sig->GetReturn(i), rets ? rets[i] : nullptr); |
| } |
| } |
| |
| const char* SafeOpcodeNameAt(const byte* pc) { |
| if (pc >= end_) return "<end>"; |
| return WasmOpcodes::ShortOpcodeName(static_cast<WasmOpcode>(*pc)); |
| } |
| |
| Value Pop(int index, ValueType expected) { |
| if (!ssa_env_->go()) { |
| // Unreachable code is essentially not typechecked. |
| return {pc_, nullptr, expected}; |
| } |
| Value val = Pop(); |
| if (val.type != expected) { |
| if (val.type != kWasmEnd) { |
| error(pc_, val.pc, "%s[%d] expected type %s, found %s of type %s", |
| SafeOpcodeNameAt(pc_), index, WasmOpcodes::TypeName(expected), |
| SafeOpcodeNameAt(val.pc), WasmOpcodes::TypeName(val.type)); |
| } |
| } |
| return val; |
| } |
| |
| Value Pop() { |
| if (!ssa_env_->go()) { |
| // Unreachable code is essentially not typechecked. |
| return {pc_, nullptr, kWasmEnd}; |
| } |
| size_t limit = control_.empty() ? 0 : control_.back().stack_depth; |
| if (stack_.size() <= limit) { |
| Value val = {pc_, nullptr, kWasmStmt}; |
| error(pc_, pc_, "%s found empty stack", SafeOpcodeNameAt(pc_)); |
| return val; |
| } |
| Value val = stack_.back(); |
| stack_.pop_back(); |
| return val; |
| } |
| |
| Value PopUpTo(int stack_depth) { |
| if (!ssa_env_->go()) { |
| // Unreachable code is essentially not typechecked. |
| return {pc_, nullptr, kWasmEnd}; |
| } |
| if (stack_depth == static_cast<int>(stack_.size())) { |
| Value val = {pc_, nullptr, kWasmStmt}; |
| return val; |
| } else { |
| DCHECK_LE(stack_depth, stack_.size()); |
| Value val = Pop(); |
| stack_.resize(stack_depth); |
| return val; |
| } |
| } |
| |
| int baserel(const byte* ptr) { |
| return base_ ? static_cast<int>(ptr - base_) : 0; |
| } |
| |
| int startrel(const byte* ptr) { return static_cast<int>(ptr - start_); } |
| |
| void BreakTo(unsigned depth) { |
| if (!ssa_env_->go()) return; |
| Control* c = &control_[control_.size() - depth - 1]; |
| if (c->is_loop()) { |
| // This is the inner loop block, which does not have a value. |
| Goto(ssa_env_, c->end_env); |
| } else { |
| // Merge the value(s) into the end of the block. |
| if (c->stack_depth + c->merge.arity > stack_.size()) { |
| error( |
| pc_, pc_, |
| "expected at least %d values on the stack for br to @%d, found %d", |
| c->merge.arity, startrel(c->pc), |
| static_cast<int>(stack_.size() - c->stack_depth)); |
| return; |
| } |
| MergeValuesInto(c); |
| } |
| } |
| |
| void FallThruTo(Control* c) { |
| if (!ssa_env_->go()) return; |
| // Merge the value(s) into the end of the block. |
| int arity = static_cast<int>(c->merge.arity); |
| if (c->stack_depth + arity != static_cast<int>(stack_.size())) { |
| error(pc_, pc_, "expected %d elements on the stack for fallthru to @%d", |
| arity, startrel(c->pc)); |
| return; |
| } |
| MergeValuesInto(c); |
| } |
| |
| inline Value& GetMergeValueFromStack(Control* c, int i) { |
| return stack_[stack_.size() - c->merge.arity + i]; |
| } |
| |
| void TypeCheckLoopFallThru(Control* c) { |
| if (!ssa_env_->go()) return; |
| // Fallthru must match arity exactly. |
| int arity = static_cast<int>(c->merge.arity); |
| if (c->stack_depth + arity != static_cast<int>(stack_.size())) { |
| error(pc_, pc_, "expected %d elements on the stack for fallthru to @%d", |
| arity, startrel(c->pc)); |
| return; |
| } |
| // Typecheck the values left on the stack. |
| for (unsigned i = 0; i < c->merge.arity; i++) { |
| Value& val = GetMergeValueFromStack(c, i); |
| Value& old = |
| c->merge.arity == 1 ? c->merge.vals.first : c->merge.vals.array[i]; |
| if (val.type != old.type) { |
| error(pc_, pc_, "type error in merge[%d] (expected %s, got %s)", i, |
| WasmOpcodes::TypeName(old.type), WasmOpcodes::TypeName(val.type)); |
| return; |
| } |
| } |
| } |
| |
| void MergeValuesInto(Control* c) { |
| SsaEnv* target = c->end_env; |
| bool first = target->state == SsaEnv::kUnreachable; |
| Goto(ssa_env_, target); |
| |
| for (unsigned i = 0; i < c->merge.arity; i++) { |
| Value& val = GetMergeValueFromStack(c, i); |
| Value& old = |
| c->merge.arity == 1 ? c->merge.vals.first : c->merge.vals.array[i]; |
| if (val.type != old.type) { |
| error(pc_, pc_, "type error in merge[%d] (expected %s, got %s)", i, |
| WasmOpcodes::TypeName(old.type), WasmOpcodes::TypeName(val.type)); |
| return; |
| } |
| if (builder_) { |
| old.node = |
| first ? val.node : CreateOrMergeIntoPhi(old.type, target->control, |
| old.node, val.node); |
| } else { |
| old.node = nullptr; |
| } |
| } |
| } |
| |
| void SetEnv(const char* reason, SsaEnv* env) { |
| #if DEBUG |
| if (FLAG_trace_wasm_decoder) { |
| char state = 'X'; |
| if (env) { |
| switch (env->state) { |
| case SsaEnv::kReached: |
| state = 'R'; |
| break; |
| case SsaEnv::kUnreachable: |
| state = 'U'; |
| break; |
| case SsaEnv::kMerged: |
| state = 'M'; |
| break; |
| case SsaEnv::kControlEnd: |
| state = 'E'; |
| break; |
| } |
| } |
| PrintF(" env = %p, state = %c, reason = %s", static_cast<void*>(env), |
| state, reason); |
| if (env && env->control) { |
| PrintF(", control = "); |
| compiler::WasmGraphBuilder::PrintDebugName(env->control); |
| } |
| PrintF("\n"); |
| } |
| #endif |
| ssa_env_ = env; |
| if (builder_) { |
| builder_->set_control_ptr(&env->control); |
| builder_->set_effect_ptr(&env->effect); |
| } |
| } |
| |
| TFNode* CheckForException(TFNode* node) { |
| if (node == nullptr) { |
| return nullptr; |
| } |
| |
| const bool inside_try_scope = current_catch_ != kNullCatch; |
| |
| if (!inside_try_scope) { |
| return node; |
| } |
| |
| TFNode* if_success = nullptr; |
| TFNode* if_exception = nullptr; |
| if (!builder_->ThrowsException(node, &if_success, &if_exception)) { |
| return node; |
| } |
| |
| SsaEnv* success_env = Steal(ssa_env_); |
| success_env->control = if_success; |
| |
| SsaEnv* exception_env = Split(success_env); |
| exception_env->control = if_exception; |
| TryInfo* try_info = current_try_info(); |
| Goto(exception_env, try_info->catch_env); |
| TFNode* exception = try_info->exception; |
| if (exception == nullptr) { |
| DCHECK_EQ(SsaEnv::kReached, try_info->catch_env->state); |
| try_info->exception = if_exception; |
| } else { |
| DCHECK_EQ(SsaEnv::kMerged, try_info->catch_env->state); |
| try_info->exception = |
| CreateOrMergeIntoPhi(kWasmI32, try_info->catch_env->control, |
| try_info->exception, if_exception); |
| } |
| |
| SetEnv("if_success", success_env); |
| return node; |
| } |
| |
| void Goto(SsaEnv* from, SsaEnv* to) { |
| DCHECK_NOT_NULL(to); |
| if (!from->go()) return; |
| switch (to->state) { |
| case SsaEnv::kUnreachable: { // Overwrite destination. |
| to->state = SsaEnv::kReached; |
| to->locals = from->locals; |
| to->control = from->control; |
| to->effect = from->effect; |
| break; |
| } |
| case SsaEnv::kReached: { // Create a new merge. |
| to->state = SsaEnv::kMerged; |
| if (!builder_) break; |
| // Merge control. |
| TFNode* controls[] = {to->control, from->control}; |
| TFNode* merge = builder_->Merge(2, controls); |
| to->control = merge; |
| // Merge effects. |
| if (from->effect != to->effect) { |
| TFNode* effects[] = {to->effect, from->effect, merge}; |
| to->effect = builder_->EffectPhi(2, effects, merge); |
| } |
| // Merge SSA values. |
| for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| TFNode* a = to->locals[i]; |
| TFNode* b = from->locals[i]; |
| if (a != b) { |
| TFNode* vals[] = {a, b}; |
| to->locals[i] = builder_->Phi(local_type_vec_[i], 2, vals, merge); |
| } |
| } |
| break; |
| } |
| case SsaEnv::kMerged: { |
| if (!builder_) break; |
| TFNode* merge = to->control; |
| // Extend the existing merge. |
| builder_->AppendToMerge(merge, from->control); |
| // Merge effects. |
| if (builder_->IsPhiWithMerge(to->effect, merge)) { |
| builder_->AppendToPhi(to->effect, from->effect); |
| } else if (to->effect != from->effect) { |
| uint32_t count = builder_->InputCount(merge); |
| TFNode** effects = builder_->Buffer(count); |
| for (uint32_t j = 0; j < count - 1; j++) { |
| effects[j] = to->effect; |
| } |
| effects[count - 1] = from->effect; |
| to->effect = builder_->EffectPhi(count, effects, merge); |
| } |
| // Merge locals. |
| for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| TFNode* tnode = to->locals[i]; |
| TFNode* fnode = from->locals[i]; |
| if (builder_->IsPhiWithMerge(tnode, merge)) { |
| builder_->AppendToPhi(tnode, fnode); |
| } else if (tnode != fnode) { |
| uint32_t count = builder_->InputCount(merge); |
| TFNode** vals = builder_->Buffer(count); |
| for (uint32_t j = 0; j < count - 1; j++) { |
| vals[j] = tnode; |
| } |
| vals[count - 1] = fnode; |
| to->locals[i] = |
| builder_->Phi(local_type_vec_[i], count, vals, merge); |
| } |
| } |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| return from->Kill(); |
| } |
| |
| TFNode* CreateOrMergeIntoPhi(ValueType type, TFNode* merge, TFNode* tnode, |
| TFNode* fnode) { |
| DCHECK_NOT_NULL(builder_); |
| if (builder_->IsPhiWithMerge(tnode, merge)) { |
| builder_->AppendToPhi(tnode, fnode); |
| } else if (tnode != fnode) { |
| uint32_t count = builder_->InputCount(merge); |
| TFNode** vals = builder_->Buffer(count); |
| for (uint32_t j = 0; j < count - 1; j++) vals[j] = tnode; |
| vals[count - 1] = fnode; |
| return builder_->Phi(type, count, vals, merge); |
| } |
| return tnode; |
| } |
| |
| SsaEnv* PrepareForLoop(const byte* pc, SsaEnv* env) { |
| if (!builder_) return Split(env); |
| if (!env->go()) return Split(env); |
| env->state = SsaEnv::kMerged; |
| |
| env->control = builder_->Loop(env->control); |
| env->effect = builder_->EffectPhi(1, &env->effect, env->control); |
| builder_->Terminate(env->effect, env->control); |
| if (FLAG_wasm_loop_assignment_analysis) { |
| BitVector* assigned = AnalyzeLoopAssignment(pc); |
| if (failed()) return env; |
| if (assigned != nullptr) { |
| // Only introduce phis for variables assigned in this loop. |
| for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| if (!assigned->Contains(i)) continue; |
| env->locals[i] = builder_->Phi(local_type_vec_[i], 1, &env->locals[i], |
| env->control); |
| } |
| SsaEnv* loop_body_env = Split(env); |
| builder_->StackCheck(position(), &(loop_body_env->effect), |
| &(loop_body_env->control)); |
| return loop_body_env; |
| } |
| } |
| |
| // Conservatively introduce phis for all local variables. |
| for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| env->locals[i] = |
| builder_->Phi(local_type_vec_[i], 1, &env->locals[i], env->control); |
| } |
| |
| SsaEnv* loop_body_env = Split(env); |
| builder_->StackCheck(position(), &(loop_body_env->effect), |
| &(loop_body_env->control)); |
| return loop_body_env; |
| } |
| |
| // Create a complete copy of the {from}. |
| SsaEnv* Split(SsaEnv* from) { |
| DCHECK_NOT_NULL(from); |
| SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| size_t size = sizeof(TFNode*) * EnvironmentCount(); |
| result->control = from->control; |
| result->effect = from->effect; |
| |
| if (from->go()) { |
| result->state = SsaEnv::kReached; |
| result->locals = |
| size > 0 ? reinterpret_cast<TFNode**>(zone_->New(size)) : nullptr; |
| memcpy(result->locals, from->locals, size); |
| } else { |
| result->state = SsaEnv::kUnreachable; |
| result->locals = nullptr; |
| } |
| |
| return result; |
| } |
| |
| // Create a copy of {from} that steals its state and leaves {from} |
| // unreachable. |
| SsaEnv* Steal(SsaEnv* from) { |
| DCHECK_NOT_NULL(from); |
| if (!from->go()) return UnreachableEnv(); |
| SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| result->state = SsaEnv::kReached; |
| result->locals = from->locals; |
| result->control = from->control; |
| result->effect = from->effect; |
| from->Kill(SsaEnv::kUnreachable); |
| return result; |
| } |
| |
| // Create an unreachable environment. |
| SsaEnv* UnreachableEnv() { |
| SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| result->state = SsaEnv::kUnreachable; |
| result->control = nullptr; |
| result->effect = nullptr; |
| result->locals = nullptr; |
| return result; |
| } |
| |
| int EnvironmentCount() { |
| if (builder_) return static_cast<int>(local_type_vec_.size()); |
| return 0; // if we aren't building a graph, don't bother with SSA renaming. |
| } |
| |
| virtual void onFirstError() { |
| limit_ = start_; // Terminate decoding loop. |
| builder_ = nullptr; // Don't build any more nodes. |
| TRACE(" !%s\n", error_msg_.get()); |
| } |
| BitVector* AnalyzeLoopAssignment(const byte* pc) { |
| if (pc >= limit_) return nullptr; |
| if (*pc != kExprLoop) return nullptr; |
| |
| BitVector* assigned = |
| new (zone_) BitVector(static_cast<int>(local_type_vec_.size()), zone_); |
| int depth = 0; |
| // Iteratively process all AST nodes nested inside the loop. |
| while (pc < limit_ && ok()) { |
| WasmOpcode opcode = static_cast<WasmOpcode>(*pc); |
| unsigned length = 1; |
| switch (opcode) { |
| case kExprLoop: |
| case kExprIf: |
| case kExprBlock: |
| case kExprTry: |
| length = OpcodeLength(pc); |
| depth++; |
| break; |
| case kExprSetLocal: // fallthru |
| case kExprTeeLocal: { |
| LocalIndexOperand operand(this, pc); |
| if (assigned->length() > 0 && |
| operand.index < static_cast<uint32_t>(assigned->length())) { |
| // Unverified code might have an out-of-bounds index. |
| assigned->Add(operand.index); |
| } |
| length = 1 + operand.length; |
| break; |
| } |
| case kExprEnd: |
| depth--; |
| break; |
| default: |
| length = OpcodeLength(pc); |
| break; |
| } |
| if (depth <= 0) break; |
| pc += length; |
| } |
| return ok() ? assigned : nullptr; |
| } |
| |
| inline wasm::WasmCodePosition position() { |
| int offset = static_cast<int>(pc_ - start_); |
| DCHECK_EQ(pc_ - start_, offset); // overflows cannot happen |
| return offset; |
| } |
| |
| inline void BuildSimpleOperator(WasmOpcode opcode, FunctionSig* sig) { |
| TFNode* node; |
| switch (sig->parameter_count()) { |
| case 1: { |
| Value val = Pop(0, sig->GetParam(0)); |
| node = BUILD(Unop, opcode, val.node, position()); |
| break; |
| } |
| case 2: { |
| Value rval = Pop(1, sig->GetParam(1)); |
| Value lval = Pop(0, sig->GetParam(0)); |
| node = BUILD(Binop, opcode, lval.node, rval.node, position()); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| node = nullptr; |
| break; |
| } |
| Push(GetReturnType(sig), node); |
| } |
| }; |
| |
| bool DecodeLocalDecls(BodyLocalDecls& decls, const byte* start, |
| const byte* end) { |
| AccountingAllocator allocator; |
| Zone tmp(&allocator, ZONE_NAME); |
| FunctionBody body = {nullptr, nullptr, nullptr, start, end}; |
| WasmFullDecoder decoder(&tmp, nullptr, body); |
| return decoder.DecodeLocalDecls(decls); |
| } |
| |
| BytecodeIterator::BytecodeIterator(const byte* start, const byte* end, |
| BodyLocalDecls* decls) |
| : Decoder(start, end) { |
| if (decls != nullptr) { |
| if (DecodeLocalDecls(*decls, start, end)) { |
| pc_ += decls->decls_encoded_size; |
| if (pc_ > end_) pc_ = end_; |
| } |
| } |
| } |
| |
| DecodeResult VerifyWasmCode(AccountingAllocator* allocator, |
| FunctionBody& body) { |
| Zone zone(allocator, ZONE_NAME); |
| WasmFullDecoder decoder(&zone, nullptr, body); |
| decoder.Decode(); |
| return decoder.toResult<DecodeStruct*>(nullptr); |
| } |
| |
| DecodeResult BuildTFGraph(AccountingAllocator* allocator, TFBuilder* builder, |
| FunctionBody& body) { |
| Zone zone(allocator, ZONE_NAME); |
| WasmFullDecoder decoder(&zone, builder, body); |
| decoder.Decode(); |
| return decoder.toResult<DecodeStruct*>(nullptr); |
| } |
| |
| unsigned OpcodeLength(const byte* pc, const byte* end) { |
| WasmDecoder decoder(nullptr, nullptr, pc, end); |
| return decoder.OpcodeLength(pc); |
| } |
| |
| void PrintWasmCodeForDebugging(const byte* start, const byte* end) { |
| AccountingAllocator allocator; |
| OFStream os(stdout); |
| PrintWasmCode(&allocator, FunctionBodyForTesting(start, end), os, nullptr); |
| } |
| |
| bool PrintWasmCode(AccountingAllocator* allocator, const FunctionBody& body, |
| std::ostream& os, |
| std::vector<std::tuple<uint32_t, int, int>>* offset_table) { |
| Zone zone(allocator, ZONE_NAME); |
| WasmFullDecoder decoder(&zone, nullptr, body); |
| int line_nr = 0; |
| |
| // Print the function signature. |
| if (body.sig) { |
| os << "// signature: " << *body.sig << std::endl; |
| ++line_nr; |
| } |
| |
| // Print the local declarations. |
| BodyLocalDecls decls(&zone); |
| BytecodeIterator i(body.start, body.end, &decls); |
| if (body.start != i.pc() && !FLAG_wasm_code_fuzzer_gen_test) { |
| os << "// locals: "; |
| for (auto p : decls.local_types) { |
| ValueType type = p.first; |
| uint32_t count = p.second; |
| os << " " << count << " " << WasmOpcodes::TypeName(type); |
| } |
| os << std::endl; |
| ++line_nr; |
| |
| for (const byte* locals = body.start; locals < i.pc(); locals++) { |
| os << (locals == body.start ? "0x" : " 0x") << AsHex(*locals, 2) << ","; |
| } |
| os << std::endl; |
| ++line_nr; |
| } |
| |
| os << "// body: " << std::endl; |
| ++line_nr; |
| unsigned control_depth = 0; |
| for (; i.has_next(); i.next()) { |
| unsigned length = decoder.OpcodeLength(i.pc()); |
| |
| WasmOpcode opcode = i.current(); |
| if (opcode == kExprElse) control_depth--; |
| |
| int num_whitespaces = control_depth < 32 ? 2 * control_depth : 64; |
| if (offset_table) { |
| offset_table->push_back( |
| std::make_tuple(i.pc_offset(), line_nr, num_whitespaces)); |
| } |
| |
| // 64 whitespaces |
| const char* padding = |
| " "; |
| os.write(padding, num_whitespaces); |
| os << "k" << WasmOpcodes::OpcodeName(opcode) << ","; |
| |
| for (size_t j = 1; j < length; ++j) { |
| os << " 0x" << AsHex(i.pc()[j], 2) << ","; |
| } |
| |
| switch (opcode) { |
| case kExprElse: |
| os << " // @" << i.pc_offset(); |
| control_depth++; |
| break; |
| case kExprLoop: |
| case kExprIf: |
| case kExprBlock: |
| case kExprTry: { |
| BlockTypeOperand operand(&i, i.pc()); |
| os << " // @" << i.pc_offset(); |
| for (unsigned i = 0; i < operand.arity; i++) { |
| os << " " << WasmOpcodes::TypeName(operand.read_entry(i)); |
| } |
| control_depth++; |
| break; |
| } |
| case kExprEnd: |
| os << " // @" << i.pc_offset(); |
| control_depth--; |
| break; |
| case kExprBr: { |
| BreakDepthOperand operand(&i, i.pc()); |
| os << " // depth=" << operand.depth; |
| break; |
| } |
| case kExprBrIf: { |
| BreakDepthOperand operand(&i, i.pc()); |
| os << " // depth=" << operand.depth; |
| break; |
| } |
| case kExprBrTable: { |
| BranchTableOperand operand(&i, i.pc()); |
| os << " // entries=" << operand.table_count; |
| break; |
| } |
| case kExprCallIndirect: { |
| CallIndirectOperand operand(&i, i.pc()); |
| os << " // sig #" << operand.index; |
| if (decoder.Complete(i.pc(), operand)) { |
| os << ": " << *operand.sig; |
| } |
| break; |
| } |
| case kExprCallFunction: { |
| CallFunctionOperand operand(&i, i.pc()); |
| os << " // function #" << operand.index; |
| if (decoder.Complete(i.pc(), operand)) { |
| os << ": " << *operand.sig; |
| } |
| break; |
| } |
| default: |
| break; |
| } |
| os << std::endl; |
| ++line_nr; |
| } |
| |
| return decoder.ok(); |
| } |
| |
| BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, size_t num_locals, |
| const byte* start, const byte* end) { |
| FunctionBody body = {nullptr, nullptr, nullptr, start, end}; |
| WasmFullDecoder decoder(zone, nullptr, body); |
| return decoder.AnalyzeLoopAssignmentForTesting(start, num_locals); |
| } |
| |
| } // namespace wasm |
| } // namespace internal |
| } // namespace v8 |