clang/lib/AST/Interp/State.h

   1 //===--- State.h - State chain for the VM and AST Walker --------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Defines the base class of the interpreter and evaluator state.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_CLANG_AST_INTERP_STATE_H
  14 #define LLVM_CLANG_AST_INTERP_STATE_H
  15
  16 #include "clang/AST/ASTDiagnostic.h"
  17 #include "clang/AST/Expr.h"
  18
  19 namespace clang {
  20 class OptionalDiagnostic;
  21
  22 /// Kinds of access we can perform on an object, for diagnostics. Note that
  23 /// we consider a member function call to be a kind of access, even though
  24 /// it is not formally an access of the object, because it has (largely) the
  25 /// same set of semantic restrictions.
  26 enum AccessKinds {
  27   AK_Read,
  28   AK_ReadObjectRepresentation,
  29   AK_Assign,
  30   AK_Increment,
  31   AK_Decrement,
  32   AK_MemberCall,
  33   AK_DynamicCast,
  34   AK_TypeId,
  35   AK_Construct,
  36   AK_Destroy,
  37 };
  38
  39 /// The order of this enum is important for diagnostics.
  40 enum CheckSubobjectKind {
  41   CSK_Base,
  42   CSK_Derived,
  43   CSK_Field,
  44   CSK_ArrayToPointer,
  45   CSK_ArrayIndex,
  46   CSK_Real,
  47   CSK_Imag
  48 };
  49
  50 namespace interp {
  51 class Frame;
  52 class SourceInfo;
  53
  54 /// Interface for the VM to interact with the AST walker's context.
  55 class State {
  56 public:
  57   virtual ~State();
  58
  59   virtual bool checkingForUndefinedBehavior() const = 0;
  60   virtual bool checkingPotentialConstantExpression() const = 0;
  61   virtual bool noteUndefinedBehavior() = 0;
  62   virtual bool keepEvaluatingAfterFailure() const = 0;
  63   virtual Frame *getCurrentFrame() = 0;
  64   virtual const Frame *getBottomFrame() const = 0;
  65   virtual bool hasActiveDiagnostic() = 0;
  66   virtual void setActiveDiagnostic(bool Flag) = 0;
  67   virtual void setFoldFailureDiagnostic(bool Flag) = 0;
  68   virtual Expr::EvalStatus &getEvalStatus() const = 0;
  69   virtual ASTContext &getCtx() const = 0;
  70   virtual bool hasPriorDiagnostic() = 0;
  71   virtual unsigned getCallStackDepth() = 0;
  72
  73 public:
  74   State() = default;
  75   /// Diagnose that the evaluation could not be folded (FF => FoldFailure)
  76   OptionalDiagnostic
  77   FFDiag(SourceLocation Loc,
  78          diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
  79          unsigned ExtraNotes = 0);
  80
  81   OptionalDiagnostic
  82   FFDiag(const Expr *E,
  83          diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
  84          unsigned ExtraNotes = 0);
  85
  86   OptionalDiagnostic
  87   FFDiag(const SourceInfo &SI,
  88          diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
  89          unsigned ExtraNotes = 0);
  90
  91   /// Diagnose that the evaluation does not produce a C++11 core constant
  92   /// expression.
  93   ///
  94   /// FIXME: Stop evaluating if we're in EM_ConstantExpression or
  95   /// EM_PotentialConstantExpression mode and we produce one of these.
  96   OptionalDiagnostic
  97   CCEDiag(SourceLocation Loc,
  98           diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
  99           unsigned ExtraNotes = 0);
 100
 101   OptionalDiagnostic
 102   CCEDiag(const Expr *E,
 103           diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
 104           unsigned ExtraNotes = 0);
 105
 106   OptionalDiagnostic
 107   CCEDiag(const SourceInfo &SI,
 108           diag::kind DiagId = diag::note_invalid_subexpr_in_const_expr,
 109           unsigned ExtraNotes = 0);
 110
 111   /// Add a note to a prior diagnostic.
 112   OptionalDiagnostic Note(SourceLocation Loc, diag::kind DiagId);
 113
 114   /// Add a stack of notes to a prior diagnostic.
 115   void addNotes(ArrayRef<PartialDiagnosticAt> Diags);
 116
 117   /// Directly reports a diagnostic message.
 118   DiagnosticBuilder report(SourceLocation Loc, diag::kind DiagId);
 119
 120   const LangOptions &getLangOpts() const;
 121
 122   /// Whether or not we're in a context where the front end requires a
 123   /// constant value.
 124   bool InConstantContext = false;
 125
 126 private:
 127   void addCallStack(unsigned Limit);
 128
 129   PartialDiagnostic &addDiag(SourceLocation Loc, diag::kind DiagId);
 130
 131   OptionalDiagnostic diag(SourceLocation Loc, diag::kind DiagId,
 132                           unsigned ExtraNotes, bool IsCCEDiag);
 133 };
 134
 135 } // namespace interp
 136 } // namespace clang
 137
 138 #endif