| // 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/base/platform/elapsed-timer.h" |
| #include "src/signature.h" |
| |
| #include "src/flags.h" |
| #include "src/handles.h" |
| #include "src/zone-containers.h" |
| |
| #include "src/wasm/ast-decoder.h" |
| #include "src/wasm/decoder.h" |
| #include "src/wasm/wasm-module.h" |
| #include "src/wasm/wasm-opcodes.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 |
| |
| // The root of a decoded tree. |
| struct Tree { |
| LocalType type; // tree type. |
| uint32_t count; // number of children. |
| const byte* pc; // start of the syntax tree. |
| TFNode* node; // node in the TurboFan graph. |
| Tree* children[1]; // pointers to children. |
| |
| WasmOpcode opcode() const { return static_cast<WasmOpcode>(*pc); } |
| }; |
| |
| |
| // A production represents an incomplete decoded tree in the LR decoder. |
| struct Production { |
| Tree* tree; // the root of the syntax tree. |
| int index; // the current index into the children of the tree. |
| |
| WasmOpcode opcode() const { return static_cast<WasmOpcode>(*pc()); } |
| const byte* pc() const { return tree->pc; } |
| bool done() const { return index >= static_cast<int>(tree->count); } |
| Tree* last() const { return index > 0 ? tree->children[index - 1] : nullptr; } |
| }; |
| |
| |
| // 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; |
| } |
| }; |
| |
| |
| // An entry in the stack of blocks during decoding. |
| struct Block { |
| SsaEnv* ssa_env; // SSA renaming environment. |
| int stack_depth; // production stack depth. |
| }; |
| |
| |
| // An entry in the stack of ifs during decoding. |
| struct IfEnv { |
| SsaEnv* false_env; |
| SsaEnv* merge_env; |
| SsaEnv** case_envs; |
| }; |
| |
| |
| // 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() ? builder_->func(__VA_ARGS__) : nullptr) |
| #define BUILD0(func) (build() ? builder_->func() : nullptr) |
| |
| |
| // A shift-reduce-parser strategy for decoding Wasm code that uses an explicit |
| // shift-reduce strategy with multiple internal stacks. |
| class LR_WasmDecoder : public Decoder { |
| public: |
| LR_WasmDecoder(Zone* zone, TFBuilder* builder) |
| : Decoder(nullptr, nullptr), |
| zone_(zone), |
| builder_(builder), |
| trees_(zone), |
| stack_(zone), |
| blocks_(zone), |
| ifs_(zone) {} |
| |
| TreeResult Decode(FunctionEnv* function_env, const byte* base, const byte* pc, |
| const byte* end) { |
| base::ElapsedTimer decode_timer; |
| if (FLAG_trace_wasm_decode_time) { |
| decode_timer.Start(); |
| } |
| trees_.clear(); |
| stack_.clear(); |
| blocks_.clear(); |
| ifs_.clear(); |
| |
| if (end < pc) { |
| error(pc, "function body end < start"); |
| return result_; |
| } |
| |
| base_ = base; |
| Reset(pc, end); |
| function_env_ = function_env; |
| |
| InitSsaEnv(); |
| DecodeFunctionBody(); |
| |
| Tree* tree = nullptr; |
| if (ok()) { |
| if (ssa_env_->go()) { |
| if (stack_.size() > 0) { |
| error(stack_.back().pc(), end, "fell off end of code"); |
| } |
| AddImplicitReturnAtEnd(); |
| } |
| if (trees_.size() == 0) { |
| if (function_env_->sig->return_count() > 0) { |
| error(start_, "no trees created"); |
| } |
| } else { |
| tree = trees_[0]; |
| } |
| } |
| |
| if (ok()) { |
| if (FLAG_trace_wasm_decode_time) { |
| double ms = decode_timer.Elapsed().InMillisecondsF(); |
| PrintF(" - decoding took %0.3f ms\n", ms); |
| } |
| TRACE("wasm-decode ok\n\n"); |
| } else { |
| TRACE("wasm-error module+%-6d func+%d: %s\n\n", baserel(error_pc_), |
| startrel(error_pc_), error_msg_.get()); |
| } |
| return toResult(tree); |
| } |
| |
| private: |
| static const size_t kErrorMsgSize = 128; |
| |
| Zone* zone_; |
| TFBuilder* builder_; |
| const byte* base_; |
| TreeResult result_; |
| |
| SsaEnv* ssa_env_; |
| FunctionEnv* function_env_; |
| |
| ZoneVector<Tree*> trees_; |
| ZoneVector<Production> stack_; |
| ZoneVector<Block> blocks_; |
| ZoneVector<IfEnv> ifs_; |
| |
| inline bool build() { return builder_ && ssa_env_->go(); } |
| |
| void InitSsaEnv() { |
| FunctionSig* sig = function_env_->sig; |
| int param_count = static_cast<int>(sig->parameter_count()); |
| 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; |
| |
| int pos = 0; |
| if (builder_) { |
| start = builder_->Start(param_count + 1); |
| // Initialize parameters. |
| for (int i = 0; i < param_count; i++) { |
| ssa_env->locals[pos++] = builder_->Param(i, sig->GetParam(i)); |
| } |
| // Initialize int32 locals. |
| if (function_env_->local_int32_count > 0) { |
| TFNode* zero = builder_->Int32Constant(0); |
| for (uint32_t i = 0; i < function_env_->local_int32_count; i++) { |
| ssa_env->locals[pos++] = zero; |
| } |
| } |
| // Initialize int64 locals. |
| if (function_env_->local_int64_count > 0) { |
| TFNode* zero = builder_->Int64Constant(0); |
| for (uint32_t i = 0; i < function_env_->local_int64_count; i++) { |
| ssa_env->locals[pos++] = zero; |
| } |
| } |
| // Initialize float32 locals. |
| if (function_env_->local_float32_count > 0) { |
| TFNode* zero = builder_->Float32Constant(0); |
| for (uint32_t i = 0; i < function_env_->local_float32_count; i++) { |
| ssa_env->locals[pos++] = zero; |
| } |
| } |
| // Initialize float64 locals. |
| if (function_env_->local_float64_count > 0) { |
| TFNode* zero = builder_->Float64Constant(0); |
| for (uint32_t i = 0; i < function_env_->local_float64_count; i++) { |
| ssa_env->locals[pos++] = zero; |
| } |
| } |
| DCHECK_EQ(function_env_->total_locals, pos); |
| DCHECK_EQ(EnvironmentCount(), pos); |
| builder_->set_module(function_env_->module); |
| } |
| ssa_env->control = start; |
| ssa_env->effect = start; |
| SetEnv("initial", ssa_env); |
| } |
| |
| void Leaf(LocalType type, TFNode* node = nullptr) { |
| size_t size = sizeof(Tree); |
| Tree* tree = reinterpret_cast<Tree*>(zone_->New(size)); |
| tree->type = type; |
| tree->count = 0; |
| tree->pc = pc_; |
| tree->node = node; |
| tree->children[0] = nullptr; |
| Reduce(tree); |
| } |
| |
| void Shift(LocalType type, uint32_t count) { |
| size_t size = |
| sizeof(Tree) + (count == 0 ? 0 : ((count - 1) * sizeof(Tree*))); |
| Tree* tree = reinterpret_cast<Tree*>(zone_->New(size)); |
| tree->type = type; |
| tree->count = count; |
| tree->pc = pc_; |
| tree->node = nullptr; |
| for (uint32_t i = 0; i < count; i++) tree->children[i] = nullptr; |
| if (count == 0) { |
| Production p = {tree, 0}; |
| Reduce(&p); |
| Reduce(tree); |
| } else { |
| stack_.push_back({tree, 0}); |
| } |
| } |
| |
| void Reduce(Tree* tree) { |
| while (true) { |
| if (stack_.size() == 0) { |
| trees_.push_back(tree); |
| break; |
| } |
| Production* p = &stack_.back(); |
| p->tree->children[p->index++] = tree; |
| Reduce(p); |
| if (p->done()) { |
| tree = p->tree; |
| stack_.pop_back(); |
| } else { |
| break; |
| } |
| } |
| } |
| |
| 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 body of a function, producing reduced trees into {result}. |
| void DecodeFunctionBody() { |
| TRACE("wasm-decode %p...%p (%d bytes) %s\n", |
| reinterpret_cast<const void*>(start_), |
| reinterpret_cast<const void*>(limit_), |
| static_cast<int>(limit_ - start_), builder_ ? "graph building" : ""); |
| |
| if (pc_ >= limit_) return; // Nothing to do. |
| |
| while (true) { // decoding loop. |
| int len = 1; |
| WasmOpcode opcode = static_cast<WasmOpcode>(*pc_); |
| TRACE("wasm-decode module+%-6d %s func+%d: 0x%02x %s\n", baserel(pc_), |
| indentation(), startrel(pc_), opcode, |
| WasmOpcodes::OpcodeName(opcode)); |
| |
| FunctionSig* sig = WasmOpcodes::Signature(opcode); |
| if (sig) { |
| // A simple expression with a fixed signature. |
| Shift(sig->GetReturn(), static_cast<uint32_t>(sig->parameter_count())); |
| pc_ += len; |
| if (pc_ >= limit_) { |
| // End of code reached or exceeded. |
| if (pc_ > limit_ && ok()) { |
| error("Beyond end of code"); |
| } |
| return; |
| } |
| continue; // back to decoding loop. |
| } |
| |
| switch (opcode) { |
| case kExprNop: |
| Leaf(kAstStmt); |
| break; |
| case kExprBlock: { |
| int length = Operand<uint8_t>(pc_); |
| if (length < 1) { |
| Leaf(kAstStmt); |
| } else { |
| Shift(kAstEnd, length); |
| // The break environment is the outer environment. |
| SsaEnv* break_env = ssa_env_; |
| PushBlock(break_env); |
| SetEnv("block:start", Steal(break_env)); |
| } |
| len = 2; |
| break; |
| } |
| case kExprLoop: { |
| int length = Operand<uint8_t>(pc_); |
| if (length < 1) { |
| Leaf(kAstStmt); |
| } else { |
| Shift(kAstEnd, length); |
| // The break environment is the outer environment. |
| SsaEnv* break_env = ssa_env_; |
| PushBlock(break_env); |
| SsaEnv* cont_env = Steal(break_env); |
| // The continue environment is the inner environment. |
| PrepareForLoop(cont_env); |
| SetEnv("loop:start", Split(cont_env)); |
| if (ssa_env_->go()) ssa_env_->state = SsaEnv::kReached; |
| PushBlock(cont_env); |
| blocks_.back().stack_depth = -1; // no production for inner block. |
| } |
| len = 2; |
| break; |
| } |
| case kExprIf: |
| Shift(kAstStmt, 2); |
| break; |
| case kExprIfElse: |
| Shift(kAstEnd, 3); // Result type is typeof(x) in {c ? x : y}. |
| break; |
| case kExprSelect: |
| Shift(kAstStmt, 3); // Result type is typeof(x) in {c ? x : y}. |
| break; |
| case kExprBr: { |
| uint32_t depth = Operand<uint8_t>(pc_); |
| Shift(kAstEnd, 1); |
| if (depth >= blocks_.size()) { |
| error("improperly nested branch"); |
| } |
| len = 2; |
| break; |
| } |
| case kExprBrIf: { |
| uint32_t depth = Operand<uint8_t>(pc_); |
| Shift(kAstStmt, 2); |
| if (depth >= blocks_.size()) { |
| error("improperly nested conditional branch"); |
| } |
| len = 2; |
| break; |
| } |
| case kExprTableSwitch: { |
| if (!checkAvailable(5)) { |
| error("expected #tableswitch <cases> <table>, fell off end"); |
| break; |
| } |
| uint16_t case_count = *reinterpret_cast<const uint16_t*>(pc_ + 1); |
| uint16_t table_count = *reinterpret_cast<const uint16_t*>(pc_ + 3); |
| len = 5 + table_count * 2; |
| |
| if (table_count == 0) { |
| error("tableswitch with 0 entries"); |
| break; |
| } |
| |
| if (!checkAvailable(len)) { |
| error("expected #tableswitch <cases> <table>, fell off end"); |
| break; |
| } |
| |
| Shift(kAstEnd, 1 + case_count); |
| |
| // Verify table. |
| for (int i = 0; i < table_count; i++) { |
| uint16_t target = |
| *reinterpret_cast<const uint16_t*>(pc_ + 5 + i * 2); |
| if (target >= 0x8000) { |
| size_t depth = target - 0x8000; |
| if (depth > blocks_.size()) { |
| error(pc_ + 5 + i * 2, "improper branch in tableswitch"); |
| } |
| } else { |
| if (target >= case_count) { |
| error(pc_ + 5 + i * 2, "invalid case target in tableswitch"); |
| } |
| } |
| } |
| break; |
| } |
| case kExprReturn: { |
| int count = static_cast<int>(function_env_->sig->return_count()); |
| if (count == 0) { |
| BUILD(Return, 0, builder_->Buffer(0)); |
| ssa_env_->Kill(); |
| Leaf(kAstEnd); |
| } else { |
| Shift(kAstEnd, count); |
| } |
| break; |
| } |
| case kExprUnreachable: { |
| BUILD0(Unreachable); |
| ssa_env_->Kill(SsaEnv::kControlEnd); |
| Leaf(kAstEnd, nullptr); |
| break; |
| } |
| case kExprI8Const: { |
| int32_t value = Operand<int8_t>(pc_); |
| Leaf(kAstI32, BUILD(Int32Constant, value)); |
| len = 2; |
| break; |
| } |
| case kExprI32Const: { |
| int32_t value = Operand<int32_t>(pc_); |
| Leaf(kAstI32, BUILD(Int32Constant, value)); |
| len = 5; |
| break; |
| } |
| case kExprI64Const: { |
| int64_t value = Operand<int64_t>(pc_); |
| Leaf(kAstI64, BUILD(Int64Constant, value)); |
| len = 9; |
| break; |
| } |
| case kExprF32Const: { |
| float value = Operand<float>(pc_); |
| Leaf(kAstF32, BUILD(Float32Constant, value)); |
| len = 5; |
| break; |
| } |
| case kExprF64Const: { |
| double value = Operand<double>(pc_); |
| Leaf(kAstF64, BUILD(Float64Constant, value)); |
| len = 9; |
| break; |
| } |
| case kExprGetLocal: { |
| uint32_t index; |
| LocalType type = LocalOperand(pc_, &index, &len); |
| TFNode* val = |
| build() && type != kAstStmt ? ssa_env_->locals[index] : nullptr; |
| Leaf(type, val); |
| break; |
| } |
| case kExprSetLocal: { |
| uint32_t index; |
| LocalType type = LocalOperand(pc_, &index, &len); |
| Shift(type, 1); |
| break; |
| } |
| case kExprLoadGlobal: { |
| uint32_t index; |
| LocalType type = GlobalOperand(pc_, &index, &len); |
| Leaf(type, BUILD(LoadGlobal, index)); |
| break; |
| } |
| case kExprStoreGlobal: { |
| uint32_t index; |
| LocalType type = GlobalOperand(pc_, &index, &len); |
| Shift(type, 1); |
| break; |
| } |
| case kExprI32LoadMem8S: |
| case kExprI32LoadMem8U: |
| case kExprI32LoadMem16S: |
| case kExprI32LoadMem16U: |
| case kExprI32LoadMem: |
| len = DecodeLoadMem(pc_, kAstI32); |
| break; |
| case kExprI64LoadMem8S: |
| case kExprI64LoadMem8U: |
| case kExprI64LoadMem16S: |
| case kExprI64LoadMem16U: |
| case kExprI64LoadMem32S: |
| case kExprI64LoadMem32U: |
| case kExprI64LoadMem: |
| len = DecodeLoadMem(pc_, kAstI64); |
| break; |
| case kExprF32LoadMem: |
| len = DecodeLoadMem(pc_, kAstF32); |
| break; |
| case kExprF64LoadMem: |
| len = DecodeLoadMem(pc_, kAstF64); |
| break; |
| case kExprI32StoreMem8: |
| case kExprI32StoreMem16: |
| case kExprI32StoreMem: |
| len = DecodeStoreMem(pc_, kAstI32); |
| break; |
| case kExprI64StoreMem8: |
| case kExprI64StoreMem16: |
| case kExprI64StoreMem32: |
| case kExprI64StoreMem: |
| len = DecodeStoreMem(pc_, kAstI64); |
| break; |
| case kExprF32StoreMem: |
| len = DecodeStoreMem(pc_, kAstF32); |
| break; |
| case kExprF64StoreMem: |
| len = DecodeStoreMem(pc_, kAstF64); |
| break; |
| case kExprMemorySize: |
| Leaf(kAstI32, BUILD(MemSize, 0)); |
| break; |
| case kExprGrowMemory: |
| Shift(kAstI32, 1); |
| break; |
| case kExprCallFunction: { |
| uint32_t unused; |
| FunctionSig* sig = FunctionSigOperand(pc_, &unused, &len); |
| if (sig) { |
| LocalType type = |
| sig->return_count() == 0 ? kAstStmt : sig->GetReturn(); |
| Shift(type, static_cast<int>(sig->parameter_count())); |
| } else { |
| Leaf(kAstI32); // error |
| } |
| break; |
| } |
| case kExprCallIndirect: { |
| uint32_t unused; |
| FunctionSig* sig = SigOperand(pc_, &unused, &len); |
| if (sig) { |
| LocalType type = |
| sig->return_count() == 0 ? kAstStmt : sig->GetReturn(); |
| Shift(type, static_cast<int>(1 + sig->parameter_count())); |
| } else { |
| Leaf(kAstI32); // error |
| } |
| break; |
| } |
| default: |
| error("Invalid opcode"); |
| return; |
| } |
| pc_ += len; |
| if (pc_ >= limit_) { |
| // End of code reached or exceeded. |
| if (pc_ > limit_ && ok()) { |
| error("Beyond end of code"); |
| } |
| return; |
| } |
| } |
| } |
| |
| void PushBlock(SsaEnv* ssa_env) { |
| blocks_.push_back({ssa_env, static_cast<int>(stack_.size() - 1)}); |
| } |
| |
| int DecodeLoadMem(const byte* pc, LocalType type) { |
| int length = 2; |
| uint32_t offset; |
| MemoryAccessOperand(pc, &length, &offset); |
| Shift(type, 1); |
| return length; |
| } |
| |
| int DecodeStoreMem(const byte* pc, LocalType type) { |
| int length = 2; |
| uint32_t offset; |
| MemoryAccessOperand(pc, &length, &offset); |
| Shift(type, 2); |
| return length; |
| } |
| |
| void AddImplicitReturnAtEnd() { |
| int retcount = static_cast<int>(function_env_->sig->return_count()); |
| if (retcount == 0) { |
| BUILD0(ReturnVoid); |
| return; |
| } |
| |
| if (static_cast<int>(trees_.size()) < retcount) { |
| error(limit_, nullptr, |
| "ImplicitReturn expects %d arguments, only %d remain", retcount, |
| static_cast<int>(trees_.size())); |
| return; |
| } |
| |
| TRACE("wasm-decode implicit return of %d args\n", retcount); |
| |
| TFNode** buffer = BUILD(Buffer, retcount); |
| for (int index = 0; index < retcount; index++) { |
| Tree* tree = trees_[trees_.size() - 1 - index]; |
| if (buffer) buffer[index] = tree->node; |
| LocalType expected = function_env_->sig->GetReturn(index); |
| if (tree->type != expected) { |
| error(limit_, tree->pc, |
| "ImplicitReturn[%d] expected type %s, found %s of type %s", index, |
| WasmOpcodes::TypeName(expected), |
| WasmOpcodes::OpcodeName(tree->opcode()), |
| WasmOpcodes::TypeName(tree->type)); |
| return; |
| } |
| } |
| |
| BUILD(Return, retcount, buffer); |
| } |
| |
| 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 Reduce(Production* p) { |
| WasmOpcode opcode = p->opcode(); |
| TRACE("-----reduce module+%-6d %s func+%d: 0x%02x %s\n", baserel(p->pc()), |
| indentation(), startrel(p->pc()), opcode, |
| WasmOpcodes::OpcodeName(opcode)); |
| FunctionSig* sig = WasmOpcodes::Signature(opcode); |
| if (sig) { |
| // A simple expression with a fixed signature. |
| TypeCheckLast(p, sig->GetParam(p->index - 1)); |
| if (p->done() && build()) { |
| if (sig->parameter_count() == 2) { |
| p->tree->node = builder_->Binop(opcode, p->tree->children[0]->node, |
| p->tree->children[1]->node); |
| } else if (sig->parameter_count() == 1) { |
| p->tree->node = builder_->Unop(opcode, p->tree->children[0]->node); |
| } else { |
| UNREACHABLE(); |
| } |
| } |
| return; |
| } |
| |
| switch (opcode) { |
| case kExprBlock: { |
| if (p->done()) { |
| Block* last = &blocks_.back(); |
| DCHECK_EQ(stack_.size() - 1, last->stack_depth); |
| // fallthrough with the last expression. |
| ReduceBreakToExprBlock(p, last); |
| SetEnv("block:end", last->ssa_env); |
| blocks_.pop_back(); |
| } |
| break; |
| } |
| case kExprLoop: { |
| if (p->done()) { |
| // Pop the continue environment. |
| blocks_.pop_back(); |
| // Get the break environment. |
| Block* last = &blocks_.back(); |
| DCHECK_EQ(stack_.size() - 1, last->stack_depth); |
| // fallthrough with the last expression. |
| ReduceBreakToExprBlock(p, last); |
| SetEnv("loop:end", last->ssa_env); |
| blocks_.pop_back(); |
| } |
| break; |
| } |
| case kExprIf: { |
| if (p->index == 1) { |
| // Condition done. Split environment for true branch. |
| TypeCheckLast(p, kAstI32); |
| SsaEnv* false_env = ssa_env_; |
| SsaEnv* true_env = Split(ssa_env_); |
| ifs_.push_back({nullptr, false_env, nullptr}); |
| BUILD(Branch, p->last()->node, &true_env->control, |
| &false_env->control); |
| SetEnv("if:true", true_env); |
| } else if (p->index == 2) { |
| // True block done. Merge true and false environments. |
| IfEnv* env = &ifs_.back(); |
| SsaEnv* merge = env->merge_env; |
| if (merge->go()) { |
| merge->state = SsaEnv::kReached; |
| Goto(ssa_env_, merge); |
| } |
| SetEnv("if:merge", merge); |
| ifs_.pop_back(); |
| } |
| break; |
| } |
| case kExprIfElse: { |
| if (p->index == 1) { |
| // Condition done. Split environment for true and false branches. |
| TypeCheckLast(p, kAstI32); |
| SsaEnv* merge_env = ssa_env_; |
| TFNode* if_true = nullptr; |
| TFNode* if_false = nullptr; |
| BUILD(Branch, p->last()->node, &if_true, &if_false); |
| SsaEnv* false_env = Split(ssa_env_); |
| SsaEnv* true_env = Steal(ssa_env_); |
| false_env->control = if_false; |
| true_env->control = if_true; |
| ifs_.push_back({false_env, merge_env, nullptr}); |
| SetEnv("if_else:true", true_env); |
| } else if (p->index == 2) { |
| // True expr done. |
| IfEnv* env = &ifs_.back(); |
| MergeIntoProduction(p, env->merge_env, p->last()); |
| // Switch to environment for false branch. |
| SsaEnv* false_env = ifs_.back().false_env; |
| SetEnv("if_else:false", false_env); |
| } else if (p->index == 3) { |
| // False expr done. |
| IfEnv* env = &ifs_.back(); |
| MergeIntoProduction(p, env->merge_env, p->last()); |
| SetEnv("if_else:merge", env->merge_env); |
| ifs_.pop_back(); |
| } |
| break; |
| } |
| case kExprSelect: { |
| if (p->index == 1) { |
| // Condition done. |
| TypeCheckLast(p, kAstI32); |
| } else if (p->index == 2) { |
| // True expression done. |
| p->tree->type = p->last()->type; |
| if (p->tree->type == kAstStmt) { |
| error(p->pc(), p->tree->children[1]->pc, |
| "select operand should be expression"); |
| } |
| } else { |
| // False expression done. |
| DCHECK(p->done()); |
| TypeCheckLast(p, p->tree->type); |
| if (build()) { |
| TFNode* controls[2]; |
| builder_->Branch(p->tree->children[0]->node, &controls[0], |
| &controls[1]); |
| TFNode* merge = builder_->Merge(2, controls); |
| TFNode* vals[2] = {p->tree->children[1]->node, |
| p->tree->children[2]->node}; |
| TFNode* phi = builder_->Phi(p->tree->type, 2, vals, merge); |
| p->tree->node = phi; |
| ssa_env_->control = merge; |
| } |
| } |
| break; |
| } |
| case kExprBr: { |
| uint32_t depth = Operand<uint8_t>(p->pc()); |
| if (depth >= blocks_.size()) { |
| error("improperly nested branch"); |
| break; |
| } |
| Block* block = &blocks_[blocks_.size() - depth - 1]; |
| ReduceBreakToExprBlock(p, block); |
| break; |
| } |
| case kExprBrIf: { |
| if (p->index == 1) { |
| TypeCheckLast(p, kAstI32); |
| } else if (p->done()) { |
| uint32_t depth = Operand<uint8_t>(p->pc()); |
| if (depth >= blocks_.size()) { |
| error("improperly nested branch"); |
| break; |
| } |
| Block* block = &blocks_[blocks_.size() - depth - 1]; |
| SsaEnv* fenv = ssa_env_; |
| SsaEnv* tenv = Split(fenv); |
| BUILD(Branch, p->tree->children[0]->node, &tenv->control, |
| &fenv->control); |
| ssa_env_ = tenv; |
| ReduceBreakToExprBlock(p, block); |
| ssa_env_ = fenv; |
| } |
| break; |
| } |
| case kExprTableSwitch: { |
| uint16_t table_count = *reinterpret_cast<const uint16_t*>(p->pc() + 3); |
| if (table_count == 1) { |
| // Degenerate switch with only a default target. |
| if (p->index == 1) { |
| SsaEnv* break_env = ssa_env_; |
| PushBlock(break_env); |
| SetEnv("switch:default", Steal(break_env)); |
| } |
| if (p->done()) { |
| Block* block = &blocks_.back(); |
| // fall through to the end. |
| ReduceBreakToExprBlock(p, block); |
| SetEnv("switch:end", block->ssa_env); |
| blocks_.pop_back(); |
| } |
| break; |
| } |
| |
| if (p->index == 1) { |
| // Switch key finished. |
| TypeCheckLast(p, kAstI32); |
| |
| TFNode* sw = BUILD(Switch, table_count, p->last()->node); |
| |
| // Allocate environments for each case. |
| uint16_t case_count = *reinterpret_cast<const uint16_t*>(p->pc() + 1); |
| SsaEnv** case_envs = zone_->NewArray<SsaEnv*>(case_count); |
| for (int i = 0; i < case_count; i++) { |
| case_envs[i] = UnreachableEnv(); |
| } |
| |
| ifs_.push_back({nullptr, nullptr, case_envs}); |
| SsaEnv* break_env = ssa_env_; |
| PushBlock(break_env); |
| SsaEnv* copy = Steal(break_env); |
| ssa_env_ = copy; |
| |
| // Build the environments for each case based on the table. |
| const uint16_t* table = |
| reinterpret_cast<const uint16_t*>(p->pc() + 5); |
| for (int i = 0; i < table_count; i++) { |
| uint16_t target = table[i]; |
| SsaEnv* env = Split(copy); |
| env->control = (i == table_count - 1) ? BUILD(IfDefault, sw) |
| : BUILD(IfValue, i, sw); |
| if (target >= 0x8000) { |
| // Targets an outer block. |
| int depth = target - 0x8000; |
| SsaEnv* tenv = blocks_[blocks_.size() - depth - 1].ssa_env; |
| Goto(env, tenv); |
| } else { |
| // Targets a case. |
| Goto(env, case_envs[target]); |
| } |
| } |
| |
| // Switch to the environment for the first case. |
| SetEnv("switch:case", case_envs[0]); |
| } else { |
| // Switch case finished. |
| if (p->done()) { |
| // Last case. Fall through to the end. |
| Block* block = &blocks_.back(); |
| ReduceBreakToExprBlock(p, block); |
| SsaEnv* next = block->ssa_env; |
| blocks_.pop_back(); |
| ifs_.pop_back(); |
| SetEnv("switch:end", next); |
| } else { |
| // Interior case. Maybe fall through to the next case. |
| SsaEnv* next = ifs_.back().case_envs[p->index - 1]; |
| if (ssa_env_->go()) Goto(ssa_env_, next); |
| SetEnv("switch:case", next); |
| } |
| } |
| break; |
| } |
| case kExprReturn: { |
| TypeCheckLast(p, function_env_->sig->GetReturn(p->index - 1)); |
| if (p->done()) { |
| if (build()) { |
| int count = p->tree->count; |
| TFNode** buffer = builder_->Buffer(count); |
| for (int i = 0; i < count; i++) { |
| buffer[i] = p->tree->children[i]->node; |
| } |
| BUILD(Return, count, buffer); |
| } |
| ssa_env_->Kill(SsaEnv::kControlEnd); |
| } |
| break; |
| } |
| case kExprSetLocal: { |
| int unused = 0; |
| uint32_t index; |
| LocalType type = LocalOperand(p->pc(), &index, &unused); |
| Tree* val = p->last(); |
| if (type == val->type) { |
| if (build()) ssa_env_->locals[index] = val->node; |
| p->tree->node = val->node; |
| } else { |
| error(p->pc(), val->pc, "Typecheck failed in SetLocal"); |
| } |
| break; |
| } |
| case kExprStoreGlobal: { |
| int unused = 0; |
| uint32_t index; |
| LocalType type = GlobalOperand(p->pc(), &index, &unused); |
| Tree* val = p->last(); |
| if (type == val->type) { |
| BUILD(StoreGlobal, index, val->node); |
| p->tree->node = val->node; |
| } else { |
| error(p->pc(), val->pc, "Typecheck failed in StoreGlobal"); |
| } |
| break; |
| } |
| |
| case kExprI32LoadMem8S: |
| return ReduceLoadMem(p, kAstI32, MachineType::Int8()); |
| case kExprI32LoadMem8U: |
| return ReduceLoadMem(p, kAstI32, MachineType::Uint8()); |
| case kExprI32LoadMem16S: |
| return ReduceLoadMem(p, kAstI32, MachineType::Int16()); |
| case kExprI32LoadMem16U: |
| return ReduceLoadMem(p, kAstI32, MachineType::Uint16()); |
| case kExprI32LoadMem: |
| return ReduceLoadMem(p, kAstI32, MachineType::Int32()); |
| |
| case kExprI64LoadMem8S: |
| return ReduceLoadMem(p, kAstI64, MachineType::Int8()); |
| case kExprI64LoadMem8U: |
| return ReduceLoadMem(p, kAstI64, MachineType::Uint8()); |
| case kExprI64LoadMem16S: |
| return ReduceLoadMem(p, kAstI64, MachineType::Int16()); |
| case kExprI64LoadMem16U: |
| return ReduceLoadMem(p, kAstI64, MachineType::Uint16()); |
| case kExprI64LoadMem32S: |
| return ReduceLoadMem(p, kAstI64, MachineType::Int32()); |
| case kExprI64LoadMem32U: |
| return ReduceLoadMem(p, kAstI64, MachineType::Uint32()); |
| case kExprI64LoadMem: |
| return ReduceLoadMem(p, kAstI64, MachineType::Int64()); |
| |
| case kExprF32LoadMem: |
| return ReduceLoadMem(p, kAstF32, MachineType::Float32()); |
| |
| case kExprF64LoadMem: |
| return ReduceLoadMem(p, kAstF64, MachineType::Float64()); |
| |
| case kExprI32StoreMem8: |
| return ReduceStoreMem(p, kAstI32, MachineType::Int8()); |
| case kExprI32StoreMem16: |
| return ReduceStoreMem(p, kAstI32, MachineType::Int16()); |
| case kExprI32StoreMem: |
| return ReduceStoreMem(p, kAstI32, MachineType::Int32()); |
| |
| case kExprI64StoreMem8: |
| return ReduceStoreMem(p, kAstI64, MachineType::Int8()); |
| case kExprI64StoreMem16: |
| return ReduceStoreMem(p, kAstI64, MachineType::Int16()); |
| case kExprI64StoreMem32: |
| return ReduceStoreMem(p, kAstI64, MachineType::Int32()); |
| case kExprI64StoreMem: |
| return ReduceStoreMem(p, kAstI64, MachineType::Int64()); |
| |
| case kExprF32StoreMem: |
| return ReduceStoreMem(p, kAstF32, MachineType::Float32()); |
| |
| case kExprF64StoreMem: |
| return ReduceStoreMem(p, kAstF64, MachineType::Float64()); |
| |
| case kExprGrowMemory: |
| TypeCheckLast(p, kAstI32); |
| // TODO(titzer): build node for GrowMemory |
| p->tree->node = BUILD(Int32Constant, 0); |
| return; |
| |
| case kExprCallFunction: { |
| int len; |
| uint32_t index; |
| FunctionSig* sig = FunctionSigOperand(p->pc(), &index, &len); |
| if (!sig) break; |
| if (p->index > 0) { |
| TypeCheckLast(p, sig->GetParam(p->index - 1)); |
| } |
| if (p->done() && build()) { |
| uint32_t count = p->tree->count + 1; |
| TFNode** buffer = builder_->Buffer(count); |
| FunctionSig* sig = FunctionSigOperand(p->pc(), &index, &len); |
| USE(sig); |
| buffer[0] = nullptr; // reserved for code object. |
| for (uint32_t i = 1; i < count; i++) { |
| buffer[i] = p->tree->children[i - 1]->node; |
| } |
| p->tree->node = builder_->CallDirect(index, buffer); |
| } |
| break; |
| } |
| case kExprCallIndirect: { |
| int len; |
| uint32_t index; |
| FunctionSig* sig = SigOperand(p->pc(), &index, &len); |
| if (p->index == 1) { |
| TypeCheckLast(p, kAstI32); |
| } else { |
| TypeCheckLast(p, sig->GetParam(p->index - 2)); |
| } |
| if (p->done() && build()) { |
| uint32_t count = p->tree->count; |
| TFNode** buffer = builder_->Buffer(count); |
| for (uint32_t i = 0; i < count; i++) { |
| buffer[i] = p->tree->children[i]->node; |
| } |
| p->tree->node = builder_->CallIndirect(index, buffer); |
| } |
| break; |
| } |
| default: |
| break; |
| } |
| } |
| |
| void ReduceBreakToExprBlock(Production* p, Block* block) { |
| if (block->stack_depth < 0) { |
| // This is the inner loop block, which does not have a value. |
| Goto(ssa_env_, block->ssa_env); |
| } else { |
| // Merge the value into the production for the block. |
| Production* bp = &stack_[block->stack_depth]; |
| MergeIntoProduction(bp, block->ssa_env, p->last()); |
| } |
| } |
| |
| void MergeIntoProduction(Production* p, SsaEnv* target, Tree* expr) { |
| if (!ssa_env_->go()) return; |
| |
| bool first = target->state == SsaEnv::kUnreachable; |
| Goto(ssa_env_, target); |
| if (expr->type == kAstEnd) return; |
| |
| if (first) { |
| // first merge to this environment; set the type and the node. |
| p->tree->type = expr->type; |
| p->tree->node = expr->node; |
| } else { |
| // merge with the existing value for this block. |
| LocalType type = p->tree->type; |
| if (expr->type != type) { |
| type = kAstStmt; |
| p->tree->type = kAstStmt; |
| p->tree->node = nullptr; |
| } else if (type != kAstStmt) { |
| p->tree->node = CreateOrMergeIntoPhi(type, target->control, |
| p->tree->node, expr->node); |
| } |
| } |
| } |
| |
| void ReduceLoadMem(Production* p, LocalType type, MachineType mem_type) { |
| DCHECK_EQ(1, p->index); |
| TypeCheckLast(p, kAstI32); // index |
| if (build()) { |
| int length = 0; |
| uint32_t offset = 0; |
| MemoryAccessOperand(p->pc(), &length, &offset); |
| p->tree->node = |
| builder_->LoadMem(type, mem_type, p->last()->node, offset); |
| } |
| } |
| |
| void ReduceStoreMem(Production* p, LocalType type, MachineType mem_type) { |
| if (p->index == 1) { |
| TypeCheckLast(p, kAstI32); // index |
| } else { |
| DCHECK_EQ(2, p->index); |
| TypeCheckLast(p, type); |
| if (build()) { |
| int length = 0; |
| uint32_t offset = 0; |
| MemoryAccessOperand(p->pc(), &length, &offset); |
| TFNode* val = p->tree->children[1]->node; |
| builder_->StoreMem(mem_type, p->tree->children[0]->node, offset, val); |
| p->tree->node = val; |
| } |
| } |
| } |
| |
| void TypeCheckLast(Production* p, LocalType expected) { |
| LocalType result = p->last()->type; |
| if (result == expected) return; |
| if (result == kAstEnd) return; |
| if (expected != kAstStmt) { |
| error(p->pc(), p->last()->pc, |
| "%s[%d] expected type %s, found %s of type %s", |
| WasmOpcodes::OpcodeName(p->opcode()), p->index - 1, |
| WasmOpcodes::TypeName(expected), |
| WasmOpcodes::OpcodeName(p->last()->opcode()), |
| WasmOpcodes::TypeName(p->last()->type)); |
| } |
| } |
| |
| void SetEnv(const char* reason, SsaEnv* env) { |
| TRACE(" env = %p, block depth = %d, reason = %s", static_cast<void*>(env), |
| static_cast<int>(blocks_.size()), reason); |
| if (env->control != nullptr && FLAG_trace_wasm_decoder) { |
| TRACE(", control = "); |
| compiler::WasmGraphBuilder::PrintDebugName(env->control); |
| } |
| TRACE("\n"); |
| ssa_env_ = env; |
| if (builder_) { |
| builder_->set_control_ptr(&env->control); |
| builder_->set_effect_ptr(&env->effect); |
| } |
| } |
| |
| 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(function_env_->GetLocalType(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(merge, 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(merge, 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(function_env_->GetLocalType(i), count, |
| vals, merge); |
| } |
| } |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| return from->Kill(); |
| } |
| |
| TFNode* CreateOrMergeIntoPhi(LocalType type, TFNode* merge, TFNode* tnode, |
| TFNode* fnode) { |
| if (builder_->IsPhiWithMerge(tnode, merge)) { |
| builder_->AppendToPhi(merge, 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; |
| } |
| |
| void BuildInfiniteLoop() { |
| if (ssa_env_->go()) { |
| PrepareForLoop(ssa_env_); |
| SsaEnv* cont_env = ssa_env_; |
| ssa_env_ = Split(ssa_env_); |
| ssa_env_->state = SsaEnv::kReached; |
| Goto(ssa_env_, cont_env); |
| } |
| } |
| |
| void PrepareForLoop(SsaEnv* env) { |
| if (env->go()) { |
| env->state = SsaEnv::kMerged; |
| if (builder_) { |
| env->control = builder_->Loop(env->control); |
| env->effect = builder_->EffectPhi(1, &env->effect, env->control); |
| builder_->Terminate(env->effect, env->control); |
| for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| env->locals[i] = builder_->Phi(function_env_->GetLocalType(i), 1, |
| &env->locals[i], env->control); |
| } |
| } |
| } |
| } |
| |
| // 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; |
| result->state = from->state == SsaEnv::kUnreachable ? SsaEnv::kUnreachable |
| : SsaEnv::kReached; |
| |
| 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; |
| } |
| |
| // Load an operand at [pc + 1]. |
| template <typename V> |
| V Operand(const byte* pc) { |
| if ((limit_ - pc) < static_cast<int>(1 + sizeof(V))) { |
| const char* msg = "Expected operand following opcode"; |
| switch (sizeof(V)) { |
| case 1: |
| msg = "Expected 1-byte operand following opcode"; |
| break; |
| case 2: |
| msg = "Expected 2-byte operand following opcode"; |
| break; |
| case 4: |
| msg = "Expected 4-byte operand following opcode"; |
| break; |
| default: |
| break; |
| } |
| error(pc, msg); |
| return -1; |
| } |
| return *reinterpret_cast<const V*>(pc + 1); |
| } |
| |
| int EnvironmentCount() { |
| if (builder_) return static_cast<int>(function_env_->GetLocalCount()); |
| return 0; // if we aren't building a graph, don't bother with SSA renaming. |
| } |
| |
| LocalType LocalOperand(const byte* pc, uint32_t* index, int* length) { |
| *index = UnsignedLEB128Operand(pc, length); |
| if (function_env_->IsValidLocal(*index)) { |
| return function_env_->GetLocalType(*index); |
| } |
| error(pc, "invalid local variable index"); |
| return kAstStmt; |
| } |
| |
| LocalType GlobalOperand(const byte* pc, uint32_t* index, int* length) { |
| *index = UnsignedLEB128Operand(pc, length); |
| if (function_env_->module->IsValidGlobal(*index)) { |
| return WasmOpcodes::LocalTypeFor( |
| function_env_->module->GetGlobalType(*index)); |
| } |
| error(pc, "invalid global variable index"); |
| return kAstStmt; |
| } |
| |
| FunctionSig* FunctionSigOperand(const byte* pc, uint32_t* index, |
| int* length) { |
| *index = UnsignedLEB128Operand(pc, length); |
| if (function_env_->module->IsValidFunction(*index)) { |
| return function_env_->module->GetFunctionSignature(*index); |
| } |
| error(pc, "invalid function index"); |
| return nullptr; |
| } |
| |
| FunctionSig* SigOperand(const byte* pc, uint32_t* index, int* length) { |
| *index = UnsignedLEB128Operand(pc, length); |
| if (function_env_->module->IsValidSignature(*index)) { |
| return function_env_->module->GetSignature(*index); |
| } |
| error(pc, "invalid signature index"); |
| return nullptr; |
| } |
| |
| uint32_t UnsignedLEB128Operand(const byte* pc, int* length) { |
| uint32_t result = 0; |
| ReadUnsignedLEB128ErrorCode error_code = |
| ReadUnsignedLEB128Operand(pc + 1, limit_, length, &result); |
| if (error_code == kInvalidLEB128) error(pc, "invalid LEB128 varint"); |
| if (error_code == kMissingLEB128) error(pc, "expected LEB128 varint"); |
| (*length)++; |
| return result; |
| } |
| |
| void MemoryAccessOperand(const byte* pc, int* length, uint32_t* offset) { |
| byte bitfield = Operand<uint8_t>(pc); |
| if (MemoryAccess::OffsetField::decode(bitfield)) { |
| *offset = UnsignedLEB128Operand(pc + 1, length); |
| (*length)++; // to account for the memory access byte |
| } else { |
| *offset = 0; |
| *length = 2; |
| } |
| } |
| |
| virtual void onFirstError() { |
| limit_ = start_; // Terminate decoding loop. |
| builder_ = nullptr; // Don't build any more nodes. |
| #if DEBUG |
| PrintStackForDebugging(); |
| #endif |
| } |
| |
| #if DEBUG |
| void PrintStackForDebugging() { PrintProduction(0); } |
| |
| void PrintProduction(size_t depth) { |
| if (depth >= stack_.size()) return; |
| Production* p = &stack_[depth]; |
| for (size_t d = 0; d < depth; d++) PrintF(" "); |
| |
| PrintF("@%d %s [%d]\n", static_cast<int>(p->tree->pc - start_), |
| WasmOpcodes::OpcodeName(p->opcode()), p->tree->count); |
| for (int i = 0; i < p->index; i++) { |
| Tree* child = p->tree->children[i]; |
| for (size_t d = 0; d <= depth; d++) PrintF(" "); |
| PrintF("@%d %s [%d]", static_cast<int>(child->pc - start_), |
| WasmOpcodes::OpcodeName(child->opcode()), child->count); |
| if (child->node) { |
| PrintF(" => TF"); |
| compiler::WasmGraphBuilder::PrintDebugName(child->node); |
| } |
| PrintF("\n"); |
| } |
| PrintProduction(depth + 1); |
| } |
| #endif |
| }; |
| |
| |
| TreeResult VerifyWasmCode(FunctionEnv* env, const byte* base, const byte* start, |
| const byte* end) { |
| Zone zone; |
| LR_WasmDecoder decoder(&zone, nullptr); |
| TreeResult result = decoder.Decode(env, base, start, end); |
| return result; |
| } |
| |
| |
| TreeResult BuildTFGraph(TFBuilder* builder, FunctionEnv* env, const byte* base, |
| const byte* start, const byte* end) { |
| Zone zone; |
| LR_WasmDecoder decoder(&zone, builder); |
| TreeResult result = decoder.Decode(env, base, start, end); |
| return result; |
| } |
| |
| |
| std::ostream& operator<<(std::ostream& os, const Tree& tree) { |
| if (tree.pc == nullptr) { |
| os << "null"; |
| return os; |
| } |
| PrintF("%s", WasmOpcodes::OpcodeName(tree.opcode())); |
| if (tree.count > 0) os << "("; |
| for (uint32_t i = 0; i < tree.count; i++) { |
| if (i > 0) os << ", "; |
| os << *tree.children[i]; |
| } |
| if (tree.count > 0) os << ")"; |
| return os; |
| } |
| |
| |
| ReadUnsignedLEB128ErrorCode ReadUnsignedLEB128Operand(const byte* pc, |
| const byte* limit, |
| int* length, |
| uint32_t* result) { |
| *result = 0; |
| const byte* ptr = pc; |
| const byte* end = pc + 5; // maximum 5 bytes. |
| if (end > limit) end = limit; |
| int shift = 0; |
| byte b = 0; |
| while (ptr < end) { |
| b = *ptr++; |
| *result = *result | ((b & 0x7F) << shift); |
| if ((b & 0x80) == 0) break; |
| shift += 7; |
| } |
| DCHECK_LE(ptr - pc, 5); |
| *length = static_cast<int>(ptr - pc); |
| if (ptr == end && (b & 0x80)) { |
| return kInvalidLEB128; |
| } else if (*length == 0) { |
| return kMissingLEB128; |
| } else { |
| return kNoError; |
| } |
| } |
| |
| |
| int OpcodeLength(const byte* pc) { |
| switch (static_cast<WasmOpcode>(*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 |
| |
| case kExprI8Const: |
| case kExprBlock: |
| case kExprLoop: |
| case kExprBr: |
| case kExprBrIf: |
| return 2; |
| case kExprI32Const: |
| case kExprF32Const: |
| return 5; |
| case kExprI64Const: |
| case kExprF64Const: |
| return 9; |
| case kExprStoreGlobal: |
| case kExprSetLocal: |
| case kExprLoadGlobal: |
| case kExprCallFunction: |
| case kExprCallIndirect: |
| case kExprGetLocal: { |
| int length; |
| uint32_t result = 0; |
| ReadUnsignedLEB128Operand(pc + 1, pc + 6, &length, &result); |
| return 1 + length; |
| } |
| case kExprTableSwitch: { |
| uint16_t table_count = *reinterpret_cast<const uint16_t*>(pc + 3); |
| return 5 + table_count * 2; |
| } |
| |
| default: |
| return 1; |
| } |
| } |
| |
| |
| int OpcodeArity(FunctionEnv* env, const byte* pc) { |
| #define DECLARE_ARITY(name, ...) \ |
| static const LocalType kTypes_##name[] = {__VA_ARGS__}; \ |
| static const int kArity_##name = \ |
| static_cast<int>(arraysize(kTypes_##name) - 1); |
| |
| FOREACH_SIGNATURE(DECLARE_ARITY); |
| #undef DECLARE_ARITY |
| |
| switch (static_cast<WasmOpcode>(*pc)) { |
| case kExprI8Const: |
| case kExprI32Const: |
| case kExprI64Const: |
| case kExprF64Const: |
| case kExprF32Const: |
| case kExprGetLocal: |
| case kExprLoadGlobal: |
| case kExprNop: |
| case kExprUnreachable: |
| return 0; |
| |
| case kExprBr: |
| case kExprStoreGlobal: |
| case kExprSetLocal: |
| return 1; |
| |
| case kExprIf: |
| case kExprBrIf: |
| return 2; |
| case kExprIfElse: |
| case kExprSelect: |
| return 3; |
| case kExprBlock: |
| case kExprLoop: |
| return *(pc + 1); |
| |
| case kExprCallFunction: { |
| int index = *(pc + 1); |
| return static_cast<int>( |
| env->module->GetFunctionSignature(index)->parameter_count()); |
| } |
| case kExprCallIndirect: { |
| int index = *(pc + 1); |
| return 1 + static_cast<int>( |
| env->module->GetSignature(index)->parameter_count()); |
| } |
| case kExprReturn: |
| return static_cast<int>(env->sig->return_count()); |
| case kExprTableSwitch: { |
| uint16_t case_count = *reinterpret_cast<const uint16_t*>(pc + 1); |
| return 1 + case_count; |
| } |
| |
| #define DECLARE_OPCODE_CASE(name, opcode, sig) \ |
| case kExpr##name: \ |
| return kArity_##sig; |
| |
| FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| FOREACH_MISC_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| FOREACH_SIMPLE_OPCODE(DECLARE_OPCODE_CASE) |
| #undef DECLARE_OPCODE_CASE |
| } |
| UNREACHABLE(); |
| return 0; |
| } |
| } // namespace wasm |
| } // namespace internal |
| } // namespace v8 |