llvm-project/clang/lib/AST/ByteCode/ByteCodeEmitter.h
Timm Baeder 83356f3b62
[clang][bytecode] Compile functions lazily (#131596)
Create the Function* handles for all functions we see, but delay the
actual compilation until we really call the function. This speeds up
compile times with the new interpreter a bit.
2025-03-17 15:58:35 +01:00

111 lines
3.2 KiB
C++

//===--- ByteCodeEmitter.h - Instruction emitter for the VM -----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Defines the instruction emitters.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_INTERP_LINKEMITTER_H
#define LLVM_CLANG_AST_INTERP_LINKEMITTER_H
#include "Context.h"
#include "PrimType.h"
#include "Program.h"
#include "Source.h"
namespace clang {
namespace interp {
enum Opcode : uint32_t;
/// An emitter which links the program to bytecode for later use.
class ByteCodeEmitter {
protected:
using LabelTy = uint32_t;
using AddrTy = uintptr_t;
using Local = Scope::Local;
public:
/// Compiles the function into the module.
void compileFunc(const FunctionDecl *FuncDecl, Function *Func = nullptr);
protected:
ByteCodeEmitter(Context &Ctx, Program &P) : Ctx(Ctx), P(P) {}
virtual ~ByteCodeEmitter() {}
/// Define a label.
void emitLabel(LabelTy Label);
/// Create a label.
LabelTy getLabel() { return ++NextLabel; }
/// Methods implemented by the compiler.
virtual bool visitFunc(const FunctionDecl *E) = 0;
virtual bool visitExpr(const Expr *E, bool DestroyToplevelScope) = 0;
virtual bool visitDeclAndReturn(const VarDecl *E, bool ConstantContext) = 0;
virtual bool visit(const Expr *E) = 0;
virtual bool emitBool(bool V, const Expr *E) = 0;
/// Emits jumps.
bool jumpTrue(const LabelTy &Label);
bool jumpFalse(const LabelTy &Label);
bool jump(const LabelTy &Label);
bool fallthrough(const LabelTy &Label);
/// Speculative execution.
bool speculate(const CallExpr *E, const LabelTy &EndLabel);
/// We're always emitting bytecode.
bool isActive() const { return true; }
/// Callback for local registration.
Local createLocal(Descriptor *D);
/// Parameter indices.
llvm::DenseMap<const ParmVarDecl *, ParamOffset> Params;
/// Lambda captures.
llvm::DenseMap<const ValueDecl *, ParamOffset> LambdaCaptures;
/// Offset of the This parameter in a lambda record.
ParamOffset LambdaThisCapture{0, false};
/// Local descriptors.
llvm::SmallVector<SmallVector<Local, 8>, 2> Descriptors;
private:
/// Current compilation context.
Context &Ctx;
/// Program to link to.
Program &P;
/// Index of the next available label.
LabelTy NextLabel = 0;
/// Offset of the next local variable.
unsigned NextLocalOffset = 0;
/// Label information for linker.
llvm::DenseMap<LabelTy, unsigned> LabelOffsets;
/// Location of label relocations.
llvm::DenseMap<LabelTy, llvm::SmallVector<unsigned, 5>> LabelRelocs;
/// Program code.
std::vector<std::byte> Code;
/// Opcode to expression mapping.
SourceMap SrcMap;
/// Returns the offset for a jump or records a relocation.
int32_t getOffset(LabelTy Label);
/// Emits an opcode.
template <typename... Tys>
bool emitOp(Opcode Op, const Tys &...Args, const SourceInfo &L);
protected:
#define GET_LINK_PROTO
#include "Opcodes.inc"
#undef GET_LINK_PROTO
};
} // namespace interp
} // namespace clang
#endif