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-rw-r--r--lib/AST/Interp/EvalEmitter.cpp253
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diff --git a/lib/AST/Interp/EvalEmitter.cpp b/lib/AST/Interp/EvalEmitter.cpp
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+//===--- EvalEmitter.cpp - 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "EvalEmitter.h"
+#include "Context.h"
+#include "Interp.h"
+#include "Opcode.h"
+#include "Program.h"
+#include "clang/AST/DeclCXX.h"
+
+using namespace clang;
+using namespace clang::interp;
+
+using APSInt = llvm::APSInt;
+template <typename T> using Expected = llvm::Expected<T>;
+
+EvalEmitter::EvalEmitter(Context &Ctx, Program &P, State &Parent,
+ InterpStack &Stk, APValue &Result)
+ : Ctx(Ctx), P(P), S(Parent, P, Stk, Ctx, this), Result(Result) {
+ // Create a dummy frame for the interpreter which does not have locals.
+ S.Current = new InterpFrame(S, nullptr, nullptr, CodePtr(), Pointer());
+}
+
+llvm::Expected<bool> EvalEmitter::interpretExpr(const Expr *E) {
+ if (this->visitExpr(E))
+ return true;
+ if (BailLocation)
+ return llvm::make_error<ByteCodeGenError>(*BailLocation);
+ return false;
+}
+
+llvm::Expected<bool> EvalEmitter::interpretDecl(const VarDecl *VD) {
+ if (this->visitDecl(VD))
+ return true;
+ if (BailLocation)
+ return llvm::make_error<ByteCodeGenError>(*BailLocation);
+ return false;
+}
+
+void EvalEmitter::emitLabel(LabelTy Label) {
+ CurrentLabel = Label;
+}
+
+EvalEmitter::LabelTy EvalEmitter::getLabel() { return NextLabel++; }
+
+Scope::Local EvalEmitter::createLocal(Descriptor *D) {
+ // Allocate memory for a local.
+ auto Memory = std::make_unique<char[]>(sizeof(Block) + D->getAllocSize());
+ auto *B = new (Memory.get()) Block(D, /*isStatic=*/false);
+ B->invokeCtor();
+
+ // Register the local.
+ unsigned Off = Locals.size();
+ Locals.insert({Off, std::move(Memory)});
+ return {Off, D};
+}
+
+bool EvalEmitter::bail(const SourceLocation &Loc) {
+ if (!BailLocation)
+ BailLocation = Loc;
+ return false;
+}
+
+bool EvalEmitter::jumpTrue(const LabelTy &Label) {
+ if (isActive()) {
+ if (S.Stk.pop<bool>())
+ ActiveLabel = Label;
+ }
+ return true;
+}
+
+bool EvalEmitter::jumpFalse(const LabelTy &Label) {
+ if (isActive()) {
+ if (!S.Stk.pop<bool>())
+ ActiveLabel = Label;
+ }
+ return true;
+}
+
+bool EvalEmitter::jump(const LabelTy &Label) {
+ if (isActive())
+ CurrentLabel = ActiveLabel = Label;
+ return true;
+}
+
+bool EvalEmitter::fallthrough(const LabelTy &Label) {
+ if (isActive())
+ ActiveLabel = Label;
+ CurrentLabel = Label;
+ return true;
+}
+
+template <PrimType OpType> bool EvalEmitter::emitRet(const SourceInfo &Info) {
+ if (!isActive())
+ return true;
+ using T = typename PrimConv<OpType>::T;
+ return ReturnValue<T>(S.Stk.pop<T>(), Result);
+}
+
+bool EvalEmitter::emitRetVoid(const SourceInfo &Info) { return true; }
+
+bool EvalEmitter::emitRetValue(const SourceInfo &Info) {
+ // Method to recursively traverse composites.
+ std::function<bool(QualType, const Pointer &, APValue &)> Composite;
+ Composite = [this, &Composite](QualType Ty, const Pointer &Ptr, APValue &R) {
+ if (auto *AT = Ty->getAs<AtomicType>())
+ Ty = AT->getValueType();
+
+ if (auto *RT = Ty->getAs<RecordType>()) {
+ auto *Record = Ptr.getRecord();
+ assert(Record && "Missing record descriptor");
+
+ bool Ok = true;
+ if (RT->getDecl()->isUnion()) {
+ const FieldDecl *ActiveField = nullptr;
+ APValue Value;
+ for (auto &F : Record->fields()) {
+ const Pointer &FP = Ptr.atField(F.Offset);
+ QualType FieldTy = F.Decl->getType();
+ if (FP.isActive()) {
+ if (llvm::Optional<PrimType> T = Ctx.classify(FieldTy)) {
+ TYPE_SWITCH(*T, Ok &= ReturnValue<T>(FP.deref<T>(), Value));
+ } else {
+ Ok &= Composite(FieldTy, FP, Value);
+ }
+ break;
+ }
+ }
+ R = APValue(ActiveField, Value);
+ } else {
+ unsigned NF = Record->getNumFields();
+ unsigned NB = Record->getNumBases();
+ unsigned NV = Ptr.isBaseClass() ? 0 : Record->getNumVirtualBases();
+
+ R = APValue(APValue::UninitStruct(), NB, NF);
+
+ for (unsigned I = 0; I < NF; ++I) {
+ const Record::Field *FD = Record->getField(I);
+ QualType FieldTy = FD->Decl->getType();
+ const Pointer &FP = Ptr.atField(FD->Offset);
+ APValue &Value = R.getStructField(I);
+
+ if (llvm::Optional<PrimType> T = Ctx.classify(FieldTy)) {
+ TYPE_SWITCH(*T, Ok &= ReturnValue<T>(FP.deref<T>(), Value));
+ } else {
+ Ok &= Composite(FieldTy, FP, Value);
+ }
+ }
+
+ for (unsigned I = 0; I < NB; ++I) {
+ const Record::Base *BD = Record->getBase(I);
+ QualType BaseTy = Ctx.getASTContext().getRecordType(BD->Decl);
+ const Pointer &BP = Ptr.atField(BD->Offset);
+ Ok &= Composite(BaseTy, BP, R.getStructBase(I));
+ }
+
+ for (unsigned I = 0; I < NV; ++I) {
+ const Record::Base *VD = Record->getVirtualBase(I);
+ QualType VirtBaseTy = Ctx.getASTContext().getRecordType(VD->Decl);
+ const Pointer &VP = Ptr.atField(VD->Offset);
+ Ok &= Composite(VirtBaseTy, VP, R.getStructBase(NB + I));
+ }
+ }
+ return Ok;
+ }
+ if (auto *AT = Ty->getAsArrayTypeUnsafe()) {
+ const size_t NumElems = Ptr.getNumElems();
+ QualType ElemTy = AT->getElementType();
+ R = APValue(APValue::UninitArray{}, NumElems, NumElems);
+
+ bool Ok = true;
+ for (unsigned I = 0; I < NumElems; ++I) {
+ APValue &Slot = R.getArrayInitializedElt(I);
+ const Pointer &EP = Ptr.atIndex(I);
+ if (llvm::Optional<PrimType> T = Ctx.classify(ElemTy)) {
+ TYPE_SWITCH(*T, Ok &= ReturnValue<T>(EP.deref<T>(), Slot));
+ } else {
+ Ok &= Composite(ElemTy, EP.narrow(), Slot);
+ }
+ }
+ return Ok;
+ }
+ llvm_unreachable("invalid value to return");
+ };
+
+ // Return the composite type.
+ const auto &Ptr = S.Stk.pop<Pointer>();
+ return Composite(Ptr.getType(), Ptr, Result);
+}
+
+bool EvalEmitter::emitGetPtrLocal(uint32_t I, const SourceInfo &Info) {
+ if (!isActive())
+ return true;
+
+ auto It = Locals.find(I);
+ assert(It != Locals.end() && "Missing local variable");
+ S.Stk.push<Pointer>(reinterpret_cast<Block *>(It->second.get()));
+ return true;
+}
+
+template <PrimType OpType>
+bool EvalEmitter::emitGetLocal(uint32_t I, const SourceInfo &Info) {
+ if (!isActive())
+ return true;
+
+ using T = typename PrimConv<OpType>::T;
+
+ auto It = Locals.find(I);
+ assert(It != Locals.end() && "Missing local variable");
+ auto *B = reinterpret_cast<Block *>(It->second.get());
+ S.Stk.push<T>(*reinterpret_cast<T *>(B + 1));
+ return true;
+}
+
+template <PrimType OpType>
+bool EvalEmitter::emitSetLocal(uint32_t I, const SourceInfo &Info) {
+ if (!isActive())
+ return true;
+
+ using T = typename PrimConv<OpType>::T;
+
+ auto It = Locals.find(I);
+ assert(It != Locals.end() && "Missing local variable");
+ auto *B = reinterpret_cast<Block *>(It->second.get());
+ *reinterpret_cast<T *>(B + 1) = S.Stk.pop<T>();
+ return true;
+}
+
+bool EvalEmitter::emitDestroy(uint32_t I, const SourceInfo &Info) {
+ if (!isActive())
+ return true;
+
+ for (auto &Local : Descriptors[I]) {
+ auto It = Locals.find(Local.Offset);
+ assert(It != Locals.end() && "Missing local variable");
+ S.deallocate(reinterpret_cast<Block *>(It->second.get()));
+ }
+
+ return true;
+}
+
+//===----------------------------------------------------------------------===//
+// Opcode evaluators
+//===----------------------------------------------------------------------===//
+
+#define GET_EVAL_IMPL
+#include "Opcodes.inc"
+#undef GET_EVAL_IMPL