v8/src/wasm/wasm-module-builder.h

274 lines
7.3 KiB
C
Raw Normal View History

// 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.
#ifndef V8_WASM_WASM_MODULE_BUILDER_H_
#define V8_WASM_WASM_MODULE_BUILDER_H_
#include "src/signature.h"
#include "src/zone/zone-containers.h"
#include "src/wasm/leb-helper.h"
#include "src/wasm/wasm-macro-gen.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-opcodes.h"
#include "src/wasm/wasm-result.h"
namespace v8 {
namespace internal {
namespace wasm {
class ZoneBuffer : public ZoneObject {
public:
static const uint32_t kInitialSize = 4096;
explicit ZoneBuffer(Zone* zone, size_t initial = kInitialSize)
: zone_(zone), buffer_(reinterpret_cast<byte*>(zone->New(initial))) {
pos_ = buffer_;
end_ = buffer_ + initial;
}
void write_u8(uint8_t x) {
EnsureSpace(1);
*(pos_++) = x;
}
void write_u16(uint16_t x) {
EnsureSpace(2);
WriteLittleEndianValue<uint16_t>(pos_, x);
pos_ += 2;
}
void write_u32(uint32_t x) {
EnsureSpace(4);
WriteLittleEndianValue<uint32_t>(pos_, x);
pos_ += 4;
}
void write_u32v(uint32_t val) {
EnsureSpace(kMaxVarInt32Size);
LEBHelper::write_u32v(&pos_, val);
}
void write_size(size_t val) {
EnsureSpace(kMaxVarInt32Size);
DCHECK_EQ(val, static_cast<uint32_t>(val));
LEBHelper::write_u32v(&pos_, static_cast<uint32_t>(val));
}
void write(const byte* data, size_t size) {
EnsureSpace(size);
memcpy(pos_, data, size);
pos_ += size;
}
size_t reserve_u32v() {
size_t off = offset();
EnsureSpace(kMaxVarInt32Size);
pos_ += kMaxVarInt32Size;
return off;
}
// Patch a (padded) u32v at the given offset to be the given value.
void patch_u32v(size_t offset, uint32_t val) {
byte* ptr = buffer_ + offset;
for (size_t pos = 0; pos != kPaddedVarInt32Size; ++pos) {
uint32_t next = val >> 7;
byte out = static_cast<byte>(val & 0x7f);
if (pos != kPaddedVarInt32Size - 1) {
*(ptr++) = 0x80 | out;
val = next;
} else {
*(ptr++) = out;
}
}
}
size_t offset() { return static_cast<size_t>(pos_ - buffer_); }
size_t size() { return static_cast<size_t>(pos_ - buffer_); }
const byte* begin() { return buffer_; }
const byte* end() { return pos_; }
void EnsureSpace(size_t size) {
if ((pos_ + size) > end_) {
size_t new_size = 4096 + size + (end_ - buffer_) * 3;
byte* new_buffer = reinterpret_cast<byte*>(zone_->New(new_size));
memcpy(new_buffer, buffer_, (pos_ - buffer_));
pos_ = new_buffer + (pos_ - buffer_);
buffer_ = new_buffer;
end_ = new_buffer + new_size;
}
DCHECK(pos_ + size <= end_);
}
byte** pos_ptr() { return &pos_; }
private:
Zone* zone_;
byte* buffer_;
byte* pos_;
byte* end_;
};
class WasmModuleBuilder;
class V8_EXPORT_PRIVATE WasmFunctionBuilder : public ZoneObject {
public:
// Building methods.
void SetSignature(FunctionSig* sig);
uint32_t AddLocal(LocalType type);
void EmitVarInt(uint32_t val);
void EmitCode(const byte* code, uint32_t code_size);
void Emit(WasmOpcode opcode);
void EmitGetLocal(uint32_t index);
void EmitSetLocal(uint32_t index);
void EmitTeeLocal(uint32_t index);
void EmitI32Const(int32_t val);
void EmitWithU8(WasmOpcode opcode, const byte immediate);
void EmitWithU8U8(WasmOpcode opcode, const byte imm1, const byte imm2);
void EmitWithVarInt(WasmOpcode opcode, uint32_t immediate);
void EmitDirectCallIndex(uint32_t index);
void SetExported();
void SetName(const char* name, int name_length);
void WriteSignature(ZoneBuffer& buffer) const;
void WriteExport(ZoneBuffer& buffer) const;
void WriteBody(ZoneBuffer& buffer) const;
bool exported() { return exported_; }
uint32_t func_index() { return func_index_; }
FunctionSig* signature();
private:
explicit WasmFunctionBuilder(WasmModuleBuilder* builder);
friend class WasmModuleBuilder;
friend class WasmTemporary;
struct DirectCallIndex {
size_t offset;
uint32_t direct_index;
};
WasmModuleBuilder* builder_;
LocalDeclEncoder locals_;
uint32_t signature_index_;
bool exported_;
uint32_t func_index_;
ZoneVector<uint8_t> body_;
ZoneVector<char> name_;
ZoneVector<uint32_t> i32_temps_;
ZoneVector<uint32_t> i64_temps_;
ZoneVector<uint32_t> f32_temps_;
ZoneVector<uint32_t> f64_temps_;
ZoneVector<DirectCallIndex> direct_calls_;
};
class WasmTemporary {
public:
WasmTemporary(WasmFunctionBuilder* builder, LocalType type) {
switch (type) {
case kAstI32:
temporary_ = &builder->i32_temps_;
break;
case kAstI64:
temporary_ = &builder->i64_temps_;
break;
case kAstF32:
temporary_ = &builder->f32_temps_;
break;
case kAstF64:
temporary_ = &builder->f64_temps_;
break;
default:
UNREACHABLE();
temporary_ = nullptr;
}
if (temporary_->size() == 0) {
// Allocate a new temporary.
index_ = builder->AddLocal(type);
} else {
// Reuse a previous temporary.
index_ = temporary_->back();
temporary_->pop_back();
}
}
~WasmTemporary() {
temporary_->push_back(index_); // return the temporary to the list.
}
uint32_t index() { return index_; }
private:
ZoneVector<uint32_t>* temporary_;
uint32_t index_;
};
class V8_EXPORT_PRIVATE WasmModuleBuilder : public ZoneObject {
public:
explicit WasmModuleBuilder(Zone* zone);
// Building methods.
uint32_t AddImport(const char* name, int name_length, FunctionSig* sig);
void SetImportName(uint32_t index, const char* name, int name_length) {
imports_[index].name = name;
imports_[index].name_length = name_length;
}
WasmFunctionBuilder* AddFunction(FunctionSig* sig = nullptr);
uint32_t AddGlobal(LocalType type, bool exported, bool mutability = true,
const WasmInitExpr& init = WasmInitExpr());
void AddDataSegment(const byte* data, uint32_t size, uint32_t dest);
uint32_t AddSignature(FunctionSig* sig);
void AddIndirectFunction(uint32_t index);
void MarkStartFunction(WasmFunctionBuilder* builder);
// Writing methods.
void WriteTo(ZoneBuffer& buffer) const;
struct CompareFunctionSigs {
bool operator()(FunctionSig* a, FunctionSig* b) const;
};
typedef ZoneMap<FunctionSig*, uint32_t, CompareFunctionSigs> SignatureMap;
Zone* zone() { return zone_; }
FunctionSig* GetSignature(uint32_t index) { return signatures_[index]; }
private:
struct WasmFunctionImport {
uint32_t sig_index;
const char* name;
int name_length;
};
struct WasmGlobal {
LocalType type;
bool exported;
bool mutability;
WasmInitExpr init;
};
struct WasmDataSegment {
ZoneVector<byte> data;
uint32_t dest;
};
friend class WasmFunctionBuilder;
Zone* zone_;
ZoneVector<FunctionSig*> signatures_;
ZoneVector<WasmFunctionImport> imports_;
ZoneVector<WasmFunctionBuilder*> functions_;
ZoneVector<WasmDataSegment> data_segments_;
ZoneVector<uint32_t> indirect_functions_;
ZoneVector<WasmGlobal> globals_;
SignatureMap signature_map_;
int start_function_index_;
};
inline FunctionSig* WasmFunctionBuilder::signature() {
return builder_->signatures_[signature_index_];
}
} // namespace wasm
} // namespace internal
} // namespace v8
#endif // V8_WASM_WASM_MODULE_BUILDER_H_