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-rw-r--r--lib/AST/Interp/ByteCodeExprGen.cpp580
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diff --git a/lib/AST/Interp/ByteCodeExprGen.cpp b/lib/AST/Interp/ByteCodeExprGen.cpp
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+++ b/lib/AST/Interp/ByteCodeExprGen.cpp
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+//===--- ByteCodeExprGen.cpp - Code generator for expressions ---*- 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 "ByteCodeExprGen.h"
+#include "ByteCodeEmitter.h"
+#include "ByteCodeGenError.h"
+#include "Context.h"
+#include "Function.h"
+#include "PrimType.h"
+#include "Program.h"
+#include "State.h"
+
+using namespace clang;
+using namespace clang::interp;
+
+using APSInt = llvm::APSInt;
+template <typename T> using Expected = llvm::Expected<T>;
+template <typename T> using Optional = llvm::Optional<T>;
+
+namespace clang {
+namespace interp {
+
+/// Scope used to handle temporaries in toplevel variable declarations.
+template <class Emitter> class DeclScope final : public LocalScope<Emitter> {
+public:
+ DeclScope(ByteCodeExprGen<Emitter> *Ctx, const VarDecl *VD)
+ : LocalScope<Emitter>(Ctx), Scope(Ctx->P, VD) {}
+
+ void addExtended(const Scope::Local &Local) override {
+ return this->addLocal(Local);
+ }
+
+private:
+ Program::DeclScope Scope;
+};
+
+/// Scope used to handle initialization methods.
+template <class Emitter> class OptionScope {
+public:
+ using InitFnRef = typename ByteCodeExprGen<Emitter>::InitFnRef;
+ using ChainedInitFnRef = std::function<bool(InitFnRef)>;
+
+ /// Root constructor, compiling or discarding primitives.
+ OptionScope(ByteCodeExprGen<Emitter> *Ctx, bool NewDiscardResult)
+ : Ctx(Ctx), OldDiscardResult(Ctx->DiscardResult),
+ OldInitFn(std::move(Ctx->InitFn)) {
+ Ctx->DiscardResult = NewDiscardResult;
+ Ctx->InitFn = llvm::Optional<InitFnRef>{};
+ }
+
+ /// Root constructor, setting up compilation state.
+ OptionScope(ByteCodeExprGen<Emitter> *Ctx, InitFnRef NewInitFn)
+ : Ctx(Ctx), OldDiscardResult(Ctx->DiscardResult),
+ OldInitFn(std::move(Ctx->InitFn)) {
+ Ctx->DiscardResult = true;
+ Ctx->InitFn = NewInitFn;
+ }
+
+ /// Extends the chain of initialisation pointers.
+ OptionScope(ByteCodeExprGen<Emitter> *Ctx, ChainedInitFnRef NewInitFn)
+ : Ctx(Ctx), OldDiscardResult(Ctx->DiscardResult),
+ OldInitFn(std::move(Ctx->InitFn)) {
+ assert(OldInitFn && "missing initializer");
+ Ctx->InitFn = [this, NewInitFn] { return NewInitFn(*OldInitFn); };
+ }
+
+ ~OptionScope() {
+ Ctx->DiscardResult = OldDiscardResult;
+ Ctx->InitFn = std::move(OldInitFn);
+ }
+
+private:
+ /// Parent context.
+ ByteCodeExprGen<Emitter> *Ctx;
+ /// Old discard flag to restore.
+ bool OldDiscardResult;
+ /// Old pointer emitter to restore.
+ llvm::Optional<InitFnRef> OldInitFn;
+};
+
+} // namespace interp
+} // namespace clang
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitCastExpr(const CastExpr *CE) {
+ auto *SubExpr = CE->getSubExpr();
+ switch (CE->getCastKind()) {
+
+ case CK_LValueToRValue: {
+ return dereference(
+ CE->getSubExpr(), DerefKind::Read,
+ [](PrimType) {
+ // Value loaded - nothing to do here.
+ return true;
+ },
+ [this, CE](PrimType T) {
+ // Pointer on stack - dereference it.
+ if (!this->emitLoadPop(T, CE))
+ return false;
+ return DiscardResult ? this->emitPop(T, CE) : true;
+ });
+ }
+
+ case CK_ArrayToPointerDecay:
+ case CK_AtomicToNonAtomic:
+ case CK_ConstructorConversion:
+ case CK_FunctionToPointerDecay:
+ case CK_NonAtomicToAtomic:
+ case CK_NoOp:
+ case CK_UserDefinedConversion:
+ return this->Visit(SubExpr);
+
+ case CK_ToVoid:
+ return discard(SubExpr);
+
+ default: {
+ // TODO: implement other casts.
+ return this->bail(CE);
+ }
+ }
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitIntegerLiteral(const IntegerLiteral *LE) {
+ if (DiscardResult)
+ return true;
+
+ auto Val = LE->getValue();
+ QualType LitTy = LE->getType();
+ if (Optional<PrimType> T = classify(LitTy))
+ return emitConst(*T, getIntWidth(LitTy), LE->getValue(), LE);
+ return this->bail(LE);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitParenExpr(const ParenExpr *PE) {
+ return this->Visit(PE->getSubExpr());
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitBinaryOperator(const BinaryOperator *BO) {
+ const Expr *LHS = BO->getLHS();
+ const Expr *RHS = BO->getRHS();
+
+ // Deal with operations which have composite or void types.
+ switch (BO->getOpcode()) {
+ case BO_Comma:
+ if (!discard(LHS))
+ return false;
+ if (!this->Visit(RHS))
+ return false;
+ return true;
+ default:
+ break;
+ }
+
+ // Typecheck the args.
+ Optional<PrimType> LT = classify(LHS->getType());
+ Optional<PrimType> RT = classify(RHS->getType());
+ if (!LT || !RT) {
+ return this->bail(BO);
+ }
+
+ if (Optional<PrimType> T = classify(BO->getType())) {
+ if (!visit(LHS))
+ return false;
+ if (!visit(RHS))
+ return false;
+
+ auto Discard = [this, T, BO](bool Result) {
+ if (!Result)
+ return false;
+ return DiscardResult ? this->emitPop(*T, BO) : true;
+ };
+
+ switch (BO->getOpcode()) {
+ case BO_EQ:
+ return Discard(this->emitEQ(*LT, BO));
+ case BO_NE:
+ return Discard(this->emitNE(*LT, BO));
+ case BO_LT:
+ return Discard(this->emitLT(*LT, BO));
+ case BO_LE:
+ return Discard(this->emitLE(*LT, BO));
+ case BO_GT:
+ return Discard(this->emitGT(*LT, BO));
+ case BO_GE:
+ return Discard(this->emitGE(*LT, BO));
+ case BO_Sub:
+ return Discard(this->emitSub(*T, BO));
+ case BO_Add:
+ return Discard(this->emitAdd(*T, BO));
+ case BO_Mul:
+ return Discard(this->emitMul(*T, BO));
+ default:
+ return this->bail(BO);
+ }
+ }
+
+ return this->bail(BO);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::discard(const Expr *E) {
+ OptionScope<Emitter> Scope(this, /*discardResult=*/true);
+ return this->Visit(E);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::visit(const Expr *E) {
+ OptionScope<Emitter> Scope(this, /*discardResult=*/false);
+ return this->Visit(E);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::visitBool(const Expr *E) {
+ if (Optional<PrimType> T = classify(E->getType())) {
+ return visit(E);
+ } else {
+ return this->bail(E);
+ }
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::visitZeroInitializer(PrimType T, const Expr *E) {
+ switch (T) {
+ case PT_Bool:
+ return this->emitZeroBool(E);
+ case PT_Sint8:
+ return this->emitZeroSint8(E);
+ case PT_Uint8:
+ return this->emitZeroUint8(E);
+ case PT_Sint16:
+ return this->emitZeroSint16(E);
+ case PT_Uint16:
+ return this->emitZeroUint16(E);
+ case PT_Sint32:
+ return this->emitZeroSint32(E);
+ case PT_Uint32:
+ return this->emitZeroUint32(E);
+ case PT_Sint64:
+ return this->emitZeroSint64(E);
+ case PT_Uint64:
+ return this->emitZeroUint64(E);
+ case PT_Ptr:
+ return this->emitNullPtr(E);
+ }
+ llvm_unreachable("unknown primitive type");
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::dereference(
+ const Expr *LV, DerefKind AK, llvm::function_ref<bool(PrimType)> Direct,
+ llvm::function_ref<bool(PrimType)> Indirect) {
+ if (Optional<PrimType> T = classify(LV->getType())) {
+ if (!LV->refersToBitField()) {
+ // Only primitive, non bit-field types can be dereferenced directly.
+ if (auto *DE = dyn_cast<DeclRefExpr>(LV)) {
+ if (!DE->getDecl()->getType()->isReferenceType()) {
+ if (auto *PD = dyn_cast<ParmVarDecl>(DE->getDecl()))
+ return dereferenceParam(LV, *T, PD, AK, Direct, Indirect);
+ if (auto *VD = dyn_cast<VarDecl>(DE->getDecl()))
+ return dereferenceVar(LV, *T, VD, AK, Direct, Indirect);
+ }
+ }
+ }
+
+ if (!visit(LV))
+ return false;
+ return Indirect(*T);
+ }
+
+ return false;
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::dereferenceParam(
+ const Expr *LV, PrimType T, const ParmVarDecl *PD, DerefKind AK,
+ llvm::function_ref<bool(PrimType)> Direct,
+ llvm::function_ref<bool(PrimType)> Indirect) {
+ auto It = this->Params.find(PD);
+ if (It != this->Params.end()) {
+ unsigned Idx = It->second;
+ switch (AK) {
+ case DerefKind::Read:
+ return DiscardResult ? true : this->emitGetParam(T, Idx, LV);
+
+ case DerefKind::Write:
+ if (!Direct(T))
+ return false;
+ if (!this->emitSetParam(T, Idx, LV))
+ return false;
+ return DiscardResult ? true : this->emitGetPtrParam(Idx, LV);
+
+ case DerefKind::ReadWrite:
+ if (!this->emitGetParam(T, Idx, LV))
+ return false;
+ if (!Direct(T))
+ return false;
+ if (!this->emitSetParam(T, Idx, LV))
+ return false;
+ return DiscardResult ? true : this->emitGetPtrParam(Idx, LV);
+ }
+ return true;
+ }
+
+ // If the param is a pointer, we can dereference a dummy value.
+ if (!DiscardResult && T == PT_Ptr && AK == DerefKind::Read) {
+ if (auto Idx = P.getOrCreateDummy(PD))
+ return this->emitGetPtrGlobal(*Idx, PD);
+ return false;
+ }
+
+ // Value cannot be produced - try to emit pointer and do stuff with it.
+ return visit(LV) && Indirect(T);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::dereferenceVar(
+ const Expr *LV, PrimType T, const VarDecl *VD, DerefKind AK,
+ llvm::function_ref<bool(PrimType)> Direct,
+ llvm::function_ref<bool(PrimType)> Indirect) {
+ auto It = Locals.find(VD);
+ if (It != Locals.end()) {
+ const auto &L = It->second;
+ switch (AK) {
+ case DerefKind::Read:
+ if (!this->emitGetLocal(T, L.Offset, LV))
+ return false;
+ return DiscardResult ? this->emitPop(T, LV) : true;
+
+ case DerefKind::Write:
+ if (!Direct(T))
+ return false;
+ if (!this->emitSetLocal(T, L.Offset, LV))
+ return false;
+ return DiscardResult ? true : this->emitGetPtrLocal(L.Offset, LV);
+
+ case DerefKind::ReadWrite:
+ if (!this->emitGetLocal(T, L.Offset, LV))
+ return false;
+ if (!Direct(T))
+ return false;
+ if (!this->emitSetLocal(T, L.Offset, LV))
+ return false;
+ return DiscardResult ? true : this->emitGetPtrLocal(L.Offset, LV);
+ }
+ } else if (auto Idx = getGlobalIdx(VD)) {
+ switch (AK) {
+ case DerefKind::Read:
+ if (!this->emitGetGlobal(T, *Idx, LV))
+ return false;
+ return DiscardResult ? this->emitPop(T, LV) : true;
+
+ case DerefKind::Write:
+ if (!Direct(T))
+ return false;
+ if (!this->emitSetGlobal(T, *Idx, LV))
+ return false;
+ return DiscardResult ? true : this->emitGetPtrGlobal(*Idx, LV);
+
+ case DerefKind::ReadWrite:
+ if (!this->emitGetGlobal(T, *Idx, LV))
+ return false;
+ if (!Direct(T))
+ return false;
+ if (!this->emitSetGlobal(T, *Idx, LV))
+ return false;
+ return DiscardResult ? true : this->emitGetPtrGlobal(*Idx, LV);
+ }
+ }
+
+ // If the declaration is a constant value, emit it here even
+ // though the declaration was not evaluated in the current scope.
+ // The access mode can only be read in this case.
+ if (!DiscardResult && AK == DerefKind::Read) {
+ if (VD->hasLocalStorage() && VD->hasInit() && !VD->isConstexpr()) {
+ QualType VT = VD->getType();
+ if (VT.isConstQualified() && VT->isFundamentalType())
+ return this->Visit(VD->getInit());
+ }
+ }
+
+ // Value cannot be produced - try to emit pointer.
+ return visit(LV) && Indirect(T);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::emitConst(PrimType T, unsigned NumBits,
+ const APInt &Value, const Expr *E) {
+ switch (T) {
+ case PT_Sint8:
+ return this->emitConstSint8(Value.getSExtValue(), E);
+ case PT_Uint8:
+ return this->emitConstUint8(Value.getZExtValue(), E);
+ case PT_Sint16:
+ return this->emitConstSint16(Value.getSExtValue(), E);
+ case PT_Uint16:
+ return this->emitConstUint16(Value.getZExtValue(), E);
+ case PT_Sint32:
+ return this->emitConstSint32(Value.getSExtValue(), E);
+ case PT_Uint32:
+ return this->emitConstUint32(Value.getZExtValue(), E);
+ case PT_Sint64:
+ return this->emitConstSint64(Value.getSExtValue(), E);
+ case PT_Uint64:
+ return this->emitConstUint64(Value.getZExtValue(), E);
+ case PT_Bool:
+ return this->emitConstBool(Value.getBoolValue(), E);
+ case PT_Ptr:
+ llvm_unreachable("Invalid integral type");
+ break;
+ }
+ llvm_unreachable("unknown primitive type");
+}
+
+template <class Emitter>
+unsigned ByteCodeExprGen<Emitter>::allocateLocalPrimitive(DeclTy &&Src,
+ PrimType Ty,
+ bool IsConst,
+ bool IsExtended) {
+ Descriptor *D = P.createDescriptor(Src, Ty, IsConst, Src.is<const Expr *>());
+ Scope::Local Local = this->createLocal(D);
+ if (auto *VD = dyn_cast_or_null<ValueDecl>(Src.dyn_cast<const Decl *>()))
+ Locals.insert({VD, Local});
+ VarScope->add(Local, IsExtended);
+ return Local.Offset;
+}
+
+template <class Emitter>
+llvm::Optional<unsigned>
+ByteCodeExprGen<Emitter>::allocateLocal(DeclTy &&Src, bool IsExtended) {
+ QualType Ty;
+
+ const ValueDecl *Key = nullptr;
+ bool IsTemporary = false;
+ if (auto *VD = dyn_cast_or_null<ValueDecl>(Src.dyn_cast<const Decl *>())) {
+ Key = VD;
+ Ty = VD->getType();
+ }
+ if (auto *E = Src.dyn_cast<const Expr *>()) {
+ IsTemporary = true;
+ Ty = E->getType();
+ }
+
+ Descriptor *D = P.createDescriptor(Src, Ty.getTypePtr(),
+ Ty.isConstQualified(), IsTemporary);
+ if (!D)
+ return {};
+
+ Scope::Local Local = this->createLocal(D);
+ if (Key)
+ Locals.insert({Key, Local});
+ VarScope->add(Local, IsExtended);
+ return Local.Offset;
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::visitInitializer(
+ const Expr *Init, InitFnRef InitFn) {
+ OptionScope<Emitter> Scope(this, InitFn);
+ return this->Visit(Init);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::getPtrVarDecl(const VarDecl *VD, const Expr *E) {
+ // Generate a pointer to the local, loading refs.
+ if (Optional<unsigned> Idx = getGlobalIdx(VD)) {
+ if (VD->getType()->isReferenceType())
+ return this->emitGetGlobalPtr(*Idx, E);
+ else
+ return this->emitGetPtrGlobal(*Idx, E);
+ }
+ return this->bail(VD);
+}
+
+template <class Emitter>
+llvm::Optional<unsigned>
+ByteCodeExprGen<Emitter>::getGlobalIdx(const VarDecl *VD) {
+ if (VD->isConstexpr()) {
+ // Constexpr decl - it must have already been defined.
+ return P.getGlobal(VD);
+ }
+ if (!VD->hasLocalStorage()) {
+ // Not constexpr, but a global var - can have pointer taken.
+ Program::DeclScope Scope(P, VD);
+ return P.getOrCreateGlobal(VD);
+ }
+ return {};
+}
+
+template <class Emitter>
+const RecordType *ByteCodeExprGen<Emitter>::getRecordTy(QualType Ty) {
+ if (auto *PT = dyn_cast<PointerType>(Ty))
+ return PT->getPointeeType()->getAs<RecordType>();
+ else
+ return Ty->getAs<RecordType>();
+}
+
+template <class Emitter>
+Record *ByteCodeExprGen<Emitter>::getRecord(QualType Ty) {
+ if (auto *RecordTy = getRecordTy(Ty)) {
+ return getRecord(RecordTy->getDecl());
+ }
+ return nullptr;
+}
+
+template <class Emitter>
+Record *ByteCodeExprGen<Emitter>::getRecord(const RecordDecl *RD) {
+ return P.getOrCreateRecord(RD);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::visitExpr(const Expr *Exp) {
+ ExprScope<Emitter> RootScope(this);
+ if (!visit(Exp))
+ return false;
+
+ if (Optional<PrimType> T = classify(Exp))
+ return this->emitRet(*T, Exp);
+ else
+ return this->emitRetValue(Exp);
+}
+
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::visitDecl(const VarDecl *VD) {
+ const Expr *Init = VD->getInit();
+
+ if (Optional<unsigned> I = P.createGlobal(VD)) {
+ if (Optional<PrimType> T = classify(VD->getType())) {
+ {
+ // Primitive declarations - compute the value and set it.
+ DeclScope<Emitter> LocalScope(this, VD);
+ if (!visit(Init))
+ return false;
+ }
+
+ // If the declaration is global, save the value for later use.
+ if (!this->emitDup(*T, VD))
+ return false;
+ if (!this->emitInitGlobal(*T, *I, VD))
+ return false;
+ return this->emitRet(*T, VD);
+ } else {
+ {
+ // Composite declarations - allocate storage and initialize it.
+ DeclScope<Emitter> LocalScope(this, VD);
+ if (!visitGlobalInitializer(Init, *I))
+ return false;
+ }
+
+ // Return a pointer to the global.
+ if (!this->emitGetPtrGlobal(*I, VD))
+ return false;
+ return this->emitRetValue(VD);
+ }
+ }
+
+ return this->bail(VD);
+}
+
+template <class Emitter>
+void ByteCodeExprGen<Emitter>::emitCleanup() {
+ for (VariableScope<Emitter> *C = VarScope; C; C = C->getParent())
+ C->emitDestruction();
+}
+
+namespace clang {
+namespace interp {
+
+template class ByteCodeExprGen<ByteCodeEmitter>;
+template class ByteCodeExprGen<EvalEmitter>;
+
+} // namespace interp
+} // namespace clang