blob: 0beae76513b4e89ea73579fedb5a2c969695bb62 [file] [log] [blame]
// 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/local-decl-encoder.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 constexpr size_t kInitialSize = 1024;
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_u64(uint64_t x) {
EnsureSpace(8);
WriteLittleEndianValue<uint64_t>(pos_, x);
pos_ += 8;
}
void write_u32v(uint32_t val) {
EnsureSpace(kMaxVarInt32Size);
LEBHelper::write_u32v(&pos_, val);
}
void write_i32v(int32_t val) {
EnsureSpace(kMaxVarInt32Size);
LEBHelper::write_i32v(&pos_, val);
}
void write_u64v(uint64_t val) {
EnsureSpace(kMaxVarInt64Size);
LEBHelper::write_u64v(&pos_, val);
}
void write_i64v(int64_t val) {
EnsureSpace(kMaxVarInt64Size);
LEBHelper::write_i64v(&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_f32(float val) { write_u32(bit_cast<uint32_t>(val)); }
void write_f64(double val) { write_u64(bit_cast<uint64_t>(val)); }
void write(const byte* data, size_t size) {
EnsureSpace(size);
memcpy(pos_, data, size);
pos_ += size;
}
void write_string(Vector<const char> name) {
write_size(name.length());
write(reinterpret_cast<const byte*>(name.start()), name.length());
}
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;
}
}
}
void patch_u8(size_t offset, byte val) {
DCHECK_GE(size(), offset);
buffer_[offset] = val;
}
size_t offset() const { return static_cast<size_t>(pos_ - buffer_); }
size_t size() const { return static_cast<size_t>(pos_ - buffer_); }
const byte* begin() const { return buffer_; }
const byte* end() const { return pos_; }
void EnsureSpace(size_t size) {
if ((pos_ + size) > end_) {
size_t new_size = size + (end_ - buffer_) * 2;
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_);
}
void Truncate(size_t size) {
DCHECK_GE(offset(), size);
pos_ = buffer_ + size;
}
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(ValueType type);
void EmitI32V(int32_t val);
void EmitU32V(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 EmitI64Const(int64_t val);
void EmitF32Const(float val);
void EmitF64Const(double val);
void EmitWithU8(WasmOpcode opcode, const byte immediate);
void EmitWithU8U8(WasmOpcode opcode, const byte imm1, const byte imm2);
void EmitWithI32V(WasmOpcode opcode, int32_t immediate);
void EmitWithU32V(WasmOpcode opcode, uint32_t immediate);
void EmitDirectCallIndex(uint32_t index);
void SetName(Vector<const char> name);
void AddAsmWasmOffset(size_t call_position, size_t to_number_position);
void SetAsmFunctionStartPosition(size_t function_position);
size_t GetPosition() const { return body_.size(); }
void FixupByte(size_t position, byte value) {
body_.patch_u8(position, value);
}
void DeleteCodeAfter(size_t position);
void WriteSignature(ZoneBuffer& buffer) const;
void WriteBody(ZoneBuffer& buffer) const;
void WriteAsmWasmOffsetTable(ZoneBuffer& buffer) const;
WasmModuleBuilder* builder() const { return builder_; }
uint32_t func_index() { return func_index_; }
FunctionSig* signature();
private:
explicit WasmFunctionBuilder(WasmModuleBuilder* builder);
friend class WasmModuleBuilder;
struct DirectCallIndex {
size_t offset;
uint32_t direct_index;
};
WasmModuleBuilder* builder_;
LocalDeclEncoder locals_;
uint32_t signature_index_;
uint32_t func_index_;
ZoneBuffer body_;
Vector<const 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_;
// Delta-encoded mapping from wasm bytes to asm.js source positions.
ZoneBuffer asm_offsets_;
uint32_t last_asm_byte_offset_ = 0;
uint32_t last_asm_source_position_ = 0;
uint32_t asm_func_start_source_position_ = 0;
};
class V8_EXPORT_PRIVATE WasmModuleBuilder : public ZoneObject {
public:
explicit WasmModuleBuilder(Zone* zone);
// Building methods.
uint32_t AddImport(Vector<const char> name, FunctionSig* sig);
WasmFunctionBuilder* AddFunction(FunctionSig* sig = nullptr);
uint32_t AddGlobal(ValueType type, bool exported, bool mutability = true,
const WasmInitExpr& init = WasmInitExpr());
uint32_t AddGlobalImport(Vector<const char> name, ValueType type);
void AddDataSegment(const byte* data, uint32_t size, uint32_t dest);
uint32_t AddSignature(FunctionSig* sig);
uint32_t AllocateIndirectFunctions(uint32_t count);
void SetIndirectFunction(uint32_t indirect, uint32_t direct);
void MarkStartFunction(WasmFunctionBuilder* builder);
void AddExport(Vector<const char> name, WasmFunctionBuilder* builder);
void SetMinMemorySize(uint32_t value);
void SetMaxMemorySize(uint32_t value);
void SetHasSharedMemory();
// Writing methods.
void WriteTo(ZoneBuffer& buffer) const;
void WriteAsmJsOffsetTable(ZoneBuffer& buffer) const;
// TODO(titzer): use SignatureMap from signature-map.h here.
// This signature map is zone-allocated, but the other is heap allocated.
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 {
Vector<const char> name;
uint32_t sig_index;
};
struct WasmFunctionExport {
Vector<const char> name;
uint32_t function_index;
};
struct WasmGlobalImport {
Vector<const char> name;
ValueTypeCode type_code;
};
struct WasmGlobal {
ValueType 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> function_imports_;
ZoneVector<WasmFunctionExport> function_exports_;
ZoneVector<WasmGlobalImport> global_imports_;
ZoneVector<WasmFunctionBuilder*> functions_;
ZoneVector<WasmDataSegment> data_segments_;
ZoneVector<uint32_t> indirect_functions_;
ZoneVector<WasmGlobal> globals_;
SignatureMap signature_map_;
int start_function_index_;
uint32_t min_memory_size_;
uint32_t max_memory_size_;
bool has_max_memory_size_;
bool has_shared_memory_;
};
inline FunctionSig* WasmFunctionBuilder::signature() {
return builder_->signatures_[signature_index_];
}
} // namespace wasm
} // namespace internal
} // namespace v8
#endif // V8_WASM_WASM_MODULE_BUILDER_H_