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Diffstat (limited to 'lib/AST/Interp/Interp.cpp')
| -rw-r--r-- | lib/AST/Interp/Interp.cpp | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/lib/AST/Interp/Interp.cpp b/lib/AST/Interp/Interp.cpp new file mode 100644 index 000000000000..1a8109cedf76 --- /dev/null +++ b/lib/AST/Interp/Interp.cpp @@ -0,0 +1,417 @@ +//===--- InterpState.cpp - Interpreter 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 "Interp.h" +#include <limits> +#include <vector> +#include "Function.h" +#include "InterpFrame.h" +#include "InterpStack.h" +#include "Opcode.h" +#include "PrimType.h" +#include "Program.h" +#include "State.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/ASTDiagnostic.h" +#include "clang/AST/CXXInheritance.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ExprCXX.h" +#include "llvm/ADT/APSInt.h" + +using namespace clang; +using namespace clang::interp; + +//===----------------------------------------------------------------------===// +// Ret +//===----------------------------------------------------------------------===// + +template <PrimType Name, class T = typename PrimConv<Name>::T> +static bool Ret(InterpState &S, CodePtr &PC, APValue &Result) { + S.CallStackDepth--; + const T &Ret = S.Stk.pop<T>(); + + assert(S.Current->getFrameOffset() == S.Stk.size() && "Invalid frame"); + if (!S.checkingPotentialConstantExpression()) + S.Current->popArgs(); + + if (InterpFrame *Caller = S.Current->Caller) { + PC = S.Current->getRetPC(); + delete S.Current; + S.Current = Caller; + S.Stk.push<T>(Ret); + } else { + delete S.Current; + S.Current = nullptr; + if (!ReturnValue<T>(Ret, Result)) + return false; + } + return true; +} + +static bool RetVoid(InterpState &S, CodePtr &PC, APValue &Result) { + S.CallStackDepth--; + + assert(S.Current->getFrameOffset() == S.Stk.size() && "Invalid frame"); + if (!S.checkingPotentialConstantExpression()) + S.Current->popArgs(); + + if (InterpFrame *Caller = S.Current->Caller) { + PC = S.Current->getRetPC(); + delete S.Current; + S.Current = Caller; + } else { + delete S.Current; + S.Current = nullptr; + } + return true; +} + +static bool RetValue(InterpState &S, CodePtr &Pt, APValue &Result) { + llvm::report_fatal_error("Interpreter cannot return values"); +} + +//===----------------------------------------------------------------------===// +// Jmp, Jt, Jf +//===----------------------------------------------------------------------===// + +static bool Jmp(InterpState &S, CodePtr &PC, int32_t Offset) { + PC += Offset; + return true; +} + +static bool Jt(InterpState &S, CodePtr &PC, int32_t Offset) { + if (S.Stk.pop<bool>()) { + PC += Offset; + } + return true; +} + +static bool Jf(InterpState &S, CodePtr &PC, int32_t Offset) { + if (!S.Stk.pop<bool>()) { + PC += Offset; + } + return true; +} + +static bool CheckInitialized(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + AccessKinds AK) { + if (Ptr.isInitialized()) + return true; + if (!S.checkingPotentialConstantExpression()) { + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_access_uninit) << AK << false; + } + return false; +} + +static bool CheckActive(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + AccessKinds AK) { + if (Ptr.isActive()) + return true; + + // Get the inactive field descriptor. + const FieldDecl *InactiveField = Ptr.getField(); + + // Walk up the pointer chain to find the union which is not active. + Pointer U = Ptr.getBase(); + while (!U.isActive()) { + U = U.getBase(); + } + + // Find the active field of the union. + Record *R = U.getRecord(); + assert(R && R->isUnion() && "Not a union"); + const FieldDecl *ActiveField = nullptr; + for (unsigned I = 0, N = R->getNumFields(); I < N; ++I) { + const Pointer &Field = U.atField(R->getField(I)->Offset); + if (Field.isActive()) { + ActiveField = Field.getField(); + break; + } + } + + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_access_inactive_union_member) + << AK << InactiveField << !ActiveField << ActiveField; + return false; +} + +static bool CheckTemporary(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + AccessKinds AK) { + if (auto ID = Ptr.getDeclID()) { + if (!Ptr.isStaticTemporary()) + return true; + + if (Ptr.getDeclDesc()->getType().isConstQualified()) + return true; + + if (S.P.getCurrentDecl() == ID) + return true; + + const SourceInfo &E = S.Current->getSource(OpPC); + S.FFDiag(E, diag::note_constexpr_access_static_temporary, 1) << AK; + S.Note(Ptr.getDeclLoc(), diag::note_constexpr_temporary_here); + return false; + } + return true; +} + +static bool CheckGlobal(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (auto ID = Ptr.getDeclID()) { + if (!Ptr.isStatic()) + return true; + + if (S.P.getCurrentDecl() == ID) + return true; + + S.FFDiag(S.Current->getLocation(OpPC), diag::note_constexpr_modify_global); + return false; + } + return true; +} + +namespace clang { +namespace interp { + +bool CheckExtern(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (!Ptr.isExtern()) + return true; + + if (!S.checkingPotentialConstantExpression()) { + auto *VD = Ptr.getDeclDesc()->asValueDecl(); + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_ltor_non_constexpr, 1) << VD; + S.Note(VD->getLocation(), diag::note_declared_at); + } + return false; +} + +bool CheckArray(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (!Ptr.isUnknownSizeArray()) + return true; + const SourceInfo &E = S.Current->getSource(OpPC); + S.FFDiag(E, diag::note_constexpr_unsized_array_indexed); + return false; +} + +bool CheckLive(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + AccessKinds AK) { + const auto &Src = S.Current->getSource(OpPC); + if (Ptr.isZero()) { + + if (Ptr.isField()) + S.FFDiag(Src, diag::note_constexpr_null_subobject) << CSK_Field; + else + S.FFDiag(Src, diag::note_constexpr_access_null) << AK; + + return false; + } + + if (!Ptr.isLive()) { + bool IsTemp = Ptr.isTemporary(); + + S.FFDiag(Src, diag::note_constexpr_lifetime_ended, 1) << AK << !IsTemp; + + if (IsTemp) + S.Note(Ptr.getDeclLoc(), diag::note_constexpr_temporary_here); + else + S.Note(Ptr.getDeclLoc(), diag::note_declared_at); + + return false; + } + + return true; +} + +bool CheckNull(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + CheckSubobjectKind CSK) { + if (!Ptr.isZero()) + return true; + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_null_subobject) << CSK; + return false; +} + +bool CheckRange(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + AccessKinds AK) { + if (!Ptr.isOnePastEnd()) + return true; + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_access_past_end) << AK; + return false; +} + +bool CheckRange(InterpState &S, CodePtr OpPC, const Pointer &Ptr, + CheckSubobjectKind CSK) { + if (!Ptr.isElementPastEnd()) + return true; + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_past_end_subobject) << CSK; + return false; +} + +bool CheckConst(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + assert(Ptr.isLive() && "Pointer is not live"); + if (!Ptr.isConst()) { + return true; + } + + const QualType Ty = Ptr.getType(); + const SourceInfo &Loc = S.Current->getSource(OpPC); + S.FFDiag(Loc, diag::note_constexpr_modify_const_type) << Ty; + return false; +} + +bool CheckMutable(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + assert(Ptr.isLive() && "Pointer is not live"); + if (!Ptr.isMutable()) { + return true; + } + + const SourceInfo &Loc = S.Current->getSource(OpPC); + const FieldDecl *Field = Ptr.getField(); + S.FFDiag(Loc, diag::note_constexpr_access_mutable, 1) << AK_Read << Field; + S.Note(Field->getLocation(), diag::note_declared_at); + return false; +} + +bool CheckLoad(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (!CheckLive(S, OpPC, Ptr, AK_Read)) + return false; + if (!CheckExtern(S, OpPC, Ptr)) + return false; + if (!CheckRange(S, OpPC, Ptr, AK_Read)) + return false; + if (!CheckInitialized(S, OpPC, Ptr, AK_Read)) + return false; + if (!CheckActive(S, OpPC, Ptr, AK_Read)) + return false; + if (!CheckTemporary(S, OpPC, Ptr, AK_Read)) + return false; + if (!CheckMutable(S, OpPC, Ptr)) + return false; + return true; +} + +bool CheckStore(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (!CheckLive(S, OpPC, Ptr, AK_Assign)) + return false; + if (!CheckExtern(S, OpPC, Ptr)) + return false; + if (!CheckRange(S, OpPC, Ptr, AK_Assign)) + return false; + if (!CheckGlobal(S, OpPC, Ptr)) + return false; + if (!CheckConst(S, OpPC, Ptr)) + return false; + return true; +} + +bool CheckInvoke(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (!CheckLive(S, OpPC, Ptr, AK_MemberCall)) + return false; + if (!CheckExtern(S, OpPC, Ptr)) + return false; + if (!CheckRange(S, OpPC, Ptr, AK_MemberCall)) + return false; + return true; +} + +bool CheckInit(InterpState &S, CodePtr OpPC, const Pointer &Ptr) { + if (!CheckLive(S, OpPC, Ptr, AK_Assign)) + return false; + if (!CheckRange(S, OpPC, Ptr, AK_Assign)) + return false; + return true; +} + +bool CheckCallable(InterpState &S, CodePtr OpPC, Function *F) { + const SourceLocation &Loc = S.Current->getLocation(OpPC); + + if (F->isVirtual()) { + if (!S.getLangOpts().CPlusPlus2a) { + S.CCEDiag(Loc, diag::note_constexpr_virtual_call); + return false; + } + } + + if (!F->isConstexpr()) { + if (S.getLangOpts().CPlusPlus11) { + const FunctionDecl *DiagDecl = F->getDecl(); + + // If this function is not constexpr because it is an inherited + // non-constexpr constructor, diagnose that directly. + auto *CD = dyn_cast<CXXConstructorDecl>(DiagDecl); + if (CD && CD->isInheritingConstructor()) { + auto *Inherited = CD->getInheritedConstructor().getConstructor(); + if (!Inherited->isConstexpr()) + DiagDecl = CD = Inherited; + } + + // FIXME: If DiagDecl is an implicitly-declared special member function + // or an inheriting constructor, we should be much more explicit about why + // it's not constexpr. + if (CD && CD->isInheritingConstructor()) + S.FFDiag(Loc, diag::note_constexpr_invalid_inhctor, 1) + << CD->getInheritedConstructor().getConstructor()->getParent(); + else + S.FFDiag(Loc, diag::note_constexpr_invalid_function, 1) + << DiagDecl->isConstexpr() << (bool)CD << DiagDecl; + S.Note(DiagDecl->getLocation(), diag::note_declared_at); + } else { + S.FFDiag(Loc, diag::note_invalid_subexpr_in_const_expr); + } + return false; + } + + return true; +} + +bool CheckThis(InterpState &S, CodePtr OpPC, const Pointer &This) { + if (!This.isZero()) + return true; + + const SourceInfo &Loc = S.Current->getSource(OpPC); + + bool IsImplicit = false; + if (auto *E = dyn_cast_or_null<CXXThisExpr>(Loc.asExpr())) + IsImplicit = E->isImplicit(); + + if (S.getLangOpts().CPlusPlus11) + S.FFDiag(Loc, diag::note_constexpr_this) << IsImplicit; + else + S.FFDiag(Loc); + + return false; +} + +bool CheckPure(InterpState &S, CodePtr OpPC, const CXXMethodDecl *MD) { + if (!MD->isPure()) + return true; + const SourceInfo &E = S.Current->getSource(OpPC); + S.FFDiag(E, diag::note_constexpr_pure_virtual_call, 1) << MD; + S.Note(MD->getLocation(), diag::note_declared_at); + return false; +} +bool Interpret(InterpState &S, APValue &Result) { + CodePtr PC = S.Current->getPC(); + + for (;;) { + auto Op = PC.read<Opcode>(); + CodePtr OpPC = PC; + + switch (Op) { +#define GET_INTERP +#include "Opcodes.inc" +#undef GET_INTERP + } + } +} + +} // namespace interp +} // namespace clang |