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Unified Diff: src/wasm/ast-decoder.cc

Issue 2594973003: [wasm] Rename ast-decoder.* to function-body-decoder.* (Closed)
Patch Set: Created 4 years ago
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Index: src/wasm/ast-decoder.cc
diff --git a/src/wasm/ast-decoder.cc b/src/wasm/ast-decoder.cc
deleted file mode 100644
index 320b086a8c8865dc4d9d468689bd661e4a89ffc7..0000000000000000000000000000000000000000
--- a/src/wasm/ast-decoder.cc
+++ /dev/null
@@ -1,2068 +0,0 @@
-// 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/ast-decoder.h"
-#include "src/wasm/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;
- LocalType 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<LocalType>* 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 = kAstStmt;
- }
- 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) {
- PrintAstForDebugging(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(AstLocalDecls& 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;
- LocalType 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<LocalType, 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(), kAstI32);
- }
- return AnalyzeLoopAssignment(pc);
- }
-
- private:
- static const size_t kErrorMsgSize = 128;
-
- Zone* zone_;
- TFBuilder* builder_;
- const byte* base_;
-
- SsaEnv* ssa_env_;
-
- ZoneVector<LocalType> 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, local_type_vec_[index]);
- index++;
- }
- while (index < local_type_vec_.size()) {
- LocalType 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(LocalType type) {
- switch (type) {
- case kAstI32:
- return builder_->Int32Constant(0);
- case kAstI64:
- return builder_->Int64Constant(0);
- case kAstF32:
- return builder_->Float32Constant(0);
- case kAstF64:
- return builder_->Float64Constant(0);
- case kAstS128:
- 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");
- LocalType type;
- switch (code) {
- case kLocalI32:
- type = kAstI32;
- break;
- case kLocalI64:
- type = kAstI64;
- break;
- case kLocalF32:
- type = kAstF32;
- break;
- case kLocalF64:
- type = kAstF64;
- break;
- case kLocalS128:
- type = kAstS128;
- 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, kAstI32);
- 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, kAstI32);
- 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, kAstI32);
- Value fval = Pop();
- Value tval = Pop();
- if (tval.type == kAstStmt || tval.type != fval.type) {
- if (tval.type != kAstEnd && fval.type != kAstEnd) {
- error("type mismatch in select");
- break;
- }
- }
- if (build()) {
- DCHECK(tval.type != kAstEnd);
- DCHECK(fval.type != kAstEnd);
- DCHECK(cond.type != kAstEnd);
- 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, kAstI32);
- 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, kAstI32);
- 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(kAstI32, BUILD(Int32Constant, operand.value));
- len = 1 + operand.length;
- break;
- }
- case kExprI32Const: {
- ImmI32Operand operand(this, pc_);
- Push(kAstI32, BUILD(Int32Constant, operand.value));
- len = 1 + operand.length;
- break;
- }
- case kExprI64Const: {
- ImmI64Operand operand(this, pc_);
- Push(kAstI64, BUILD(Int64Constant, operand.value));
- len = 1 + operand.length;
- break;
- }
- case kExprF32Const: {
- ImmF32Operand operand(this, pc_);
- Push(kAstF32, BUILD(Float32Constant, operand.value));
- len = 1 + operand.length;
- break;
- }
- case kExprF64Const: {
- ImmF64Operand operand(this, pc_);
- Push(kAstF64, 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(kAstI32, MachineType::Int8());
- break;
- case kExprI32LoadMem8U:
- len = DecodeLoadMem(kAstI32, MachineType::Uint8());
- break;
- case kExprI32LoadMem16S:
- len = DecodeLoadMem(kAstI32, MachineType::Int16());
- break;
- case kExprI32LoadMem16U:
- len = DecodeLoadMem(kAstI32, MachineType::Uint16());
- break;
- case kExprI32LoadMem:
- len = DecodeLoadMem(kAstI32, MachineType::Int32());
- break;
- case kExprI64LoadMem8S:
- len = DecodeLoadMem(kAstI64, MachineType::Int8());
- break;
- case kExprI64LoadMem8U:
- len = DecodeLoadMem(kAstI64, MachineType::Uint8());
- break;
- case kExprI64LoadMem16S:
- len = DecodeLoadMem(kAstI64, MachineType::Int16());
- break;
- case kExprI64LoadMem16U:
- len = DecodeLoadMem(kAstI64, MachineType::Uint16());
- break;
- case kExprI64LoadMem32S:
- len = DecodeLoadMem(kAstI64, MachineType::Int32());
- break;
- case kExprI64LoadMem32U:
- len = DecodeLoadMem(kAstI64, MachineType::Uint32());
- break;
- case kExprI64LoadMem:
- len = DecodeLoadMem(kAstI64, MachineType::Int64());
- break;
- case kExprF32LoadMem:
- len = DecodeLoadMem(kAstF32, MachineType::Float32());
- break;
- case kExprF64LoadMem:
- len = DecodeLoadMem(kAstF64, MachineType::Float64());
- break;
- case kExprI32StoreMem8:
- len = DecodeStoreMem(kAstI32, MachineType::Int8());
- break;
- case kExprI32StoreMem16:
- len = DecodeStoreMem(kAstI32, MachineType::Int16());
- break;
- case kExprI32StoreMem:
- len = DecodeStoreMem(kAstI32, MachineType::Int32());
- break;
- case kExprI64StoreMem8:
- len = DecodeStoreMem(kAstI64, MachineType::Int8());
- break;
- case kExprI64StoreMem16:
- len = DecodeStoreMem(kAstI64, MachineType::Int16());
- break;
- case kExprI64StoreMem32:
- len = DecodeStoreMem(kAstI64, MachineType::Int32());
- break;
- case kExprI64StoreMem:
- len = DecodeStoreMem(kAstI64, MachineType::Int64());
- break;
- case kExprF32StoreMem:
- len = DecodeStoreMem(kAstF32, MachineType::Float32());
- break;
- case kExprF64StoreMem:
- len = DecodeStoreMem(kAstF64, MachineType::Float64());
- break;
- case kExprGrowMemory: {
- MemoryIndexOperand operand(this, pc_);
- if (module_->module->origin != kAsmJsOrigin) {
- Value val = Pop(0, kAstI32);
- Push(kAstI32, 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(kAstI32, 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, kAstI32);
- 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;
- }
- }
-
- LocalType GetReturnType(FunctionSig* sig) {
- return sig->return_count() == 0 ? kAstStmt : 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(LocalType type, MachineType mem_type) {
- MemoryAccessOperand operand(this, pc_,
- ElementSizeLog2Of(mem_type.representation()));
-
- Value index = Pop(0, kAstI32);
- TFNode* node = BUILD(LoadMem, type, mem_type, index.node, operand.offset,
- operand.alignment, position());
- Push(type, node);
- return 1 + operand.length;
- }
-
- int DecodeStoreMem(LocalType type, MachineType mem_type) {
- MemoryAccessOperand operand(this, pc_,
- ElementSizeLog2Of(mem_type.representation()));
- Value val = Pop(1, type);
- Value index = Pop(0, kAstI32);
- BUILD(StoreMem, mem_type, index.node, operand.offset, operand.alignment,
- val.node, position());
- return 1 + operand.length;
- }
-
- unsigned ExtractLane(WasmOpcode opcode, LocalType type) {
- LaneOperand operand(this, pc_);
- if (Validate(pc_, operand)) {
- compiler::NodeVector inputs(1, zone_);
- inputs[0] = Pop(0, LocalType::kSimd128).node;
- TFNode* node = BUILD(SimdLaneOp, opcode, operand.lane, inputs);
- Push(type, node);
- }
- return operand.length;
- }
-
- unsigned ReplaceLane(WasmOpcode opcode, LocalType type) {
- LaneOperand operand(this, pc_);
- if (Validate(pc_, operand)) {
- compiler::NodeVector inputs(2, zone_);
- inputs[1] = Pop(1, type).node;
- inputs[0] = Pop(0, LocalType::kSimd128).node;
- TFNode* node = BUILD(SimdLaneOp, opcode, operand.lane, inputs);
- Push(LocalType::kSimd128, node);
- }
- return operand.length;
- }
-
- unsigned DecodeSimdOpcode(WasmOpcode opcode) {
- unsigned len = 0;
- switch (opcode) {
- case kExprI32x4ExtractLane: {
- len = ExtractLane(opcode, LocalType::kWord32);
- break;
- }
- case kExprF32x4ExtractLane: {
- len = ExtractLane(opcode, LocalType::kFloat32);
- break;
- }
- case kExprI32x4ReplaceLane: {
- len = ReplaceLane(opcode, LocalType::kWord32);
- break;
- }
- case kExprF32x4ReplaceLane: {
- len = ReplaceLane(opcode, LocalType::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(LocalType type, TFNode* node) {
- if (type != kAstStmt && type != kAstEnd) {
- 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, LocalType 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 != kAstEnd) {
- 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, kAstEnd};
- }
- size_t limit = control_.empty() ? 0 : control_.back().stack_depth;
- if (stack_.size() <= limit) {
- Value val = {pc_, nullptr, kAstStmt};
- 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, kAstEnd};
- }
- if (stack_depth == static_cast<int>(stack_.size())) {
- Value val = {pc_, nullptr, kAstStmt};
- 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(kAstI32, 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(LocalType 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(AstLocalDecls& 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,
- AstLocalDecls* 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 PrintAstForDebugging(const byte* start, const byte* end) {
- AccountingAllocator allocator;
- OFStream os(stdout);
- PrintAst(&allocator, FunctionBodyForTesting(start, end), os, nullptr);
-}
-
-bool PrintAst(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.
- AstLocalDecls 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) {
- LocalType 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
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