llvm-project/clang/lib/AST/Interp/Source.h

119 lines
3.3 KiB
C++

//===--- Source.h - Source location provider 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 a program which organises and links multiple bytecode functions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_INTERP_SOURCE_H
#define LLVM_CLANG_AST_INTERP_SOURCE_H
#include "clang/AST/Decl.h"
#include "clang/AST/Stmt.h"
#include "llvm/Support/Endian.h"
namespace clang {
namespace interp {
class Function;
/// Pointer into the code segment.
class CodePtr {
public:
CodePtr() : Ptr(nullptr) {}
CodePtr &operator+=(int32_t Offset) {
Ptr += Offset;
return *this;
}
int32_t operator-(const CodePtr &RHS) const {
assert(Ptr != nullptr && RHS.Ptr != nullptr && "Invalid code pointer");
return Ptr - RHS.Ptr;
}
CodePtr operator-(size_t RHS) const {
assert(Ptr != nullptr && "Invalid code pointer");
return CodePtr(Ptr - RHS);
}
bool operator!=(const CodePtr &RHS) const { return Ptr != RHS.Ptr; }
/// Reads data and advances the pointer.
template <typename T> T read() {
T Value = ReadHelper<T>(Ptr);
Ptr += sizeof(T);
return Value;
}
private:
/// Constructor used by Function to generate pointers.
CodePtr(const char *Ptr) : Ptr(Ptr) {}
/// Helper to decode a value or a pointer.
template <typename T>
static typename std::enable_if<!std::is_pointer<T>::value, T>::type
ReadHelper(const char *Ptr) {
using namespace llvm::support;
return endian::read<T, endianness::native, 1>(Ptr);
}
template <typename T>
static typename std::enable_if<std::is_pointer<T>::value, T>::type
ReadHelper(const char *Ptr) {
using namespace llvm::support;
auto Punned = endian::read<uintptr_t, endianness::native, 1>(Ptr);
return reinterpret_cast<T>(Punned);
}
private:
friend class Function;
/// Pointer into the code owned by a function.
const char *Ptr;
};
/// Describes the statement/declaration an opcode was generated from.
class SourceInfo {
public:
SourceInfo() {}
SourceInfo(const Stmt *E) : Source(E) {}
SourceInfo(const Decl *D) : Source(D) {}
SourceLocation getLoc() const;
const Stmt *asStmt() const { return Source.dyn_cast<const Stmt *>(); }
const Decl *asDecl() const { return Source.dyn_cast<const Decl *>(); }
const Expr *asExpr() const;
operator bool() const { return !Source.isNull(); }
private:
llvm::PointerUnion<const Decl *, const Stmt *> Source;
};
using SourceMap = std::vector<std::pair<unsigned, SourceInfo>>;
/// Interface for classes which map locations to sources.
class SourceMapper {
public:
virtual ~SourceMapper() {}
/// Returns source information for a given PC in a function.
virtual SourceInfo getSource(Function *F, CodePtr PC) const = 0;
/// Returns the expression if an opcode belongs to one, null otherwise.
const Expr *getExpr(Function *F, CodePtr PC) const;
/// Returns the location from which an opcode originates.
SourceLocation getLocation(Function *F, CodePtr PC) const;
};
} // namespace interp
} // namespace clang
#endif