//===--- Context.cpp - Context for the constexpr 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 "Context.h"
#include "ByteCodeEmitter.h"
#include "ByteCodeExprGen.h"
#include "ByteCodeStmtGen.h"
#include "EvalEmitter.h"
#include "Interp.h"
#include "InterpFrame.h"
#include "InterpStack.h"
#include "PrimType.h"
#include "Program.h"
#include "clang/AST/Expr.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
using namespace clang::interp;
Context::Context(ASTContext &Ctx) : Ctx(Ctx), P(new Program(*this)) {}
Context::~Context() {}
bool Context::isPotentialConstantExpr(State &Parent, const FunctionDecl *FD) {
Function *Func = P->getFunction(FD);
if (!Func) {
if (auto R = ByteCodeStmtGen<ByteCodeEmitter>(*this, *P).compileFunc(FD)) {
Func = *R;
} else {
handleAllErrors(R.takeError(), [&Parent](ByteCodeGenError &Err) {
Parent.FFDiag(Err.getLoc(), diag::err_experimental_clang_interp_failed);
});
return false;
}
}
if (!Func->isConstexpr())
return false;
APValue Dummy;
return Run(Parent, Func, Dummy);
}
bool Context::evaluateAsRValue(State &Parent, const Expr *E, APValue &Result) {
ByteCodeExprGen<EvalEmitter> C(*this, *P, Parent, Stk, Result);
return Check(Parent, C.interpretExpr(E));
}
bool Context::evaluateAsInitializer(State &Parent, const VarDecl *VD,
APValue &Result) {
ByteCodeExprGen<EvalEmitter> C(*this, *P, Parent, Stk, Result);
return Check(Parent, C.interpretDecl(VD));
}
const LangOptions &Context::getLangOpts() const { return Ctx.getLangOpts(); }
llvm::Optional<PrimType> Context::classify(QualType T) {
if (T->isReferenceType() || T->isPointerType()) {
return PT_Ptr;
}
if (T->isBooleanType())
return PT_Bool;
if (T->isSignedIntegerOrEnumerationType()) {
switch (Ctx.getIntWidth(T)) {
case 64:
return PT_Sint64;
case 32:
return PT_Sint32;
case 16:
return PT_Sint16;
case 8:
return PT_Sint8;
default:
return {};
}
}
if (T->isUnsignedIntegerOrEnumerationType()) {
switch (Ctx.getIntWidth(T)) {
case 64:
return PT_Uint64;
case 32:
return PT_Uint32;
case 16:
return PT_Uint16;
case 8:
return PT_Uint8;
default:
return {};
}
}
if (T->isNullPtrType())
return PT_Ptr;
if (auto *AT = dyn_cast<AtomicType>(T))
return classify(AT->getValueType());
return {};
}
unsigned Context::getCharBit() const {
return Ctx.getTargetInfo().getCharWidth();
}
bool Context::Run(State &Parent, Function *Func, APValue &Result) {
InterpState State(Parent, *P, Stk, *this);
State.Current = new InterpFrame(State, Func, nullptr, {}, {});
if (Interpret(State, Result))
return true;
Stk.clear();
return false;
}
bool Context::Check(State &Parent, llvm::Expected<bool> &&Flag) {
if (Flag)
return *Flag;
handleAllErrors(Flag.takeError(), [&Parent](ByteCodeGenError &Err) {
Parent.FFDiag(Err.getLoc(), diag::err_experimental_clang_interp_failed);
});
return false;
}