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
19namespace clang {
20class 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.
26enum 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.
40enum CheckSubobjectKind {
41 CSK_Base,
42 CSK_Derived,
43 CSK_Field,
44 CSK_ArrayToPointer,
45 CSK_ArrayIndex,
46 CSK_Real,
47 CSK_Imag
48};
49
50namespace interp {
51class Frame;
52class SourceInfo;
53
54/// Interface for the VM to interact with the AST walker's context.
55class State {
56public:
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
73public:
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
126private:
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
139

source code of clang/lib/AST/Interp/State.h