Timm Baeder f838d6b1b2
[clang][bytecode] Implement __noop (#106714)
This does nothing and returns 0.
2024-09-02 13:50:22 +02:00

71 lines
2.7 KiB
C++

//===--- Function.h - Bytecode function 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
//
//===----------------------------------------------------------------------===//
#include "Function.h"
#include "Opcode.h"
#include "Program.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/Basic/Builtins.h"
using namespace clang;
using namespace clang::interp;
Function::Function(Program &P, FunctionDeclTy Source, unsigned ArgSize,
llvm::SmallVectorImpl<PrimType> &&ParamTypes,
llvm::DenseMap<unsigned, ParamDescriptor> &&Params,
llvm::SmallVectorImpl<unsigned> &&ParamOffsets,
bool HasThisPointer, bool HasRVO, unsigned BuiltinID)
: P(P), Source(Source), ArgSize(ArgSize), ParamTypes(std::move(ParamTypes)),
Params(std::move(Params)), ParamOffsets(std::move(ParamOffsets)),
HasThisPointer(HasThisPointer), HasRVO(HasRVO), BuiltinID(BuiltinID) {
if (const auto *F = Source.dyn_cast<const FunctionDecl *>())
Variadic = F->isVariadic();
}
Function::ParamDescriptor Function::getParamDescriptor(unsigned Offset) const {
auto It = Params.find(Offset);
assert(It != Params.end() && "Invalid parameter offset");
return It->second;
}
SourceInfo Function::getSource(CodePtr PC) const {
assert(PC >= getCodeBegin() && "PC does not belong to this function");
assert(PC <= getCodeEnd() && "PC Does not belong to this function");
assert(hasBody() && "Function has no body");
unsigned Offset = PC - getCodeBegin();
using Elem = std::pair<unsigned, SourceInfo>;
auto It = llvm::lower_bound(SrcMap, Elem{Offset, {}}, llvm::less_first());
if (It == SrcMap.end())
return SrcMap.back().second;
return It->second;
}
bool Function::isVirtual() const {
if (const auto *M = dyn_cast_if_present<CXXMethodDecl>(
Source.dyn_cast<const FunctionDecl *>()))
return M->isVirtual();
return false;
}
/// Unevaluated builtins don't get their arguments put on the stack
/// automatically. They instead operate on the AST of their Call
/// Expression.
/// Similar information is available via ASTContext::BuiltinInfo,
/// but that is not correct for our use cases.
static bool isUnevaluatedBuiltin(unsigned BuiltinID) {
return BuiltinID == Builtin::BI__builtin_classify_type ||
BuiltinID == Builtin::BI__builtin_os_log_format_buffer_size ||
BuiltinID == Builtin::BI__builtin_constant_p ||
BuiltinID == Builtin::BI__noop;
}
bool Function::isUnevaluatedBuiltin() const {
return ::isUnevaluatedBuiltin(BuiltinID);
}