1 //===- ASTStructuralEquivalence.h -------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file defines the StructuralEquivalenceContext class which checks for
10 // structural equivalence between types.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_AST_ASTSTRUCTURALEQUIVALENCE_H
15 #define LLVM_CLANG_AST_ASTSTRUCTURALEQUIVALENCE_H
17 #include "clang/AST/DeclBase.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/DenseSet.h"
20 #include "llvm/ADT/Optional.h"
28 class DiagnosticBuilder;
33 /// \brief Whether to perform a normal or minimal equivalence check.
34 /// In case of `Minimal`, we do not perform a recursive check of decls with
36 enum class StructuralEquivalenceKind {
41 struct StructuralEquivalenceContext {
42 /// AST contexts for which we are checking structural equivalence.
43 ASTContext &FromCtx, &ToCtx;
45 // Queue of from-to Decl pairs that are to be checked to determine the final
46 // result of equivalence of a starting Decl pair.
47 std::queue<std::pair<Decl *, Decl *>> DeclsToCheck;
49 // Set of from-to Decl pairs that are already visited during the check
50 // (are in or were once in \c DeclsToCheck) of a starting Decl pair.
51 llvm::DenseSet<std::pair<Decl *, Decl *>> VisitedDecls;
53 /// Declaration (from, to) pairs that are known not to be equivalent
54 /// (which we have already complained about).
55 llvm::DenseSet<std::pair<Decl *, Decl *>> &NonEquivalentDecls;
57 StructuralEquivalenceKind EqKind;
59 /// Whether we're being strict about the spelling of types when
60 /// unifying two types.
61 bool StrictTypeSpelling;
63 /// Whether warn or error on tag type mismatches.
64 bool ErrorOnTagTypeMismatch;
66 /// Whether to complain about failures.
69 /// \c true if the last diagnostic came from ToCtx.
70 bool LastDiagFromC2 = false;
72 StructuralEquivalenceContext(
73 ASTContext &FromCtx, ASTContext &ToCtx,
74 llvm::DenseSet<std::pair<Decl *, Decl *>> &NonEquivalentDecls,
75 StructuralEquivalenceKind EqKind,
76 bool StrictTypeSpelling = false, bool Complain = true,
77 bool ErrorOnTagTypeMismatch = false)
78 : FromCtx(FromCtx), ToCtx(ToCtx), NonEquivalentDecls(NonEquivalentDecls),
79 EqKind(EqKind), StrictTypeSpelling(StrictTypeSpelling),
80 ErrorOnTagTypeMismatch(ErrorOnTagTypeMismatch), Complain(Complain) {}
82 DiagnosticBuilder Diag1(SourceLocation Loc, unsigned DiagID);
83 DiagnosticBuilder Diag2(SourceLocation Loc, unsigned DiagID);
85 /// Determine whether the two declarations are structurally
87 /// Implementation functions (all static functions in
88 /// ASTStructuralEquivalence.cpp) must never call this function because that
89 /// will wreak havoc the internal state (\c DeclsToCheck and
90 /// \c VisitedDecls members) and can cause faulty equivalent results.
91 bool IsEquivalent(Decl *D1, Decl *D2);
93 /// Determine whether the two types are structurally equivalent.
94 /// Implementation functions (all static functions in
95 /// ASTStructuralEquivalence.cpp) must never call this function because that
96 /// will wreak havoc the internal state (\c DeclsToCheck and
97 /// \c VisitedDecls members) and can cause faulty equivalent results.
98 bool IsEquivalent(QualType T1, QualType T2);
100 /// Find the index of the given anonymous struct/union within its
103 /// \returns Returns the index of this anonymous struct/union in its context,
104 /// including the next assigned index (if none of them match). Returns an
105 /// empty option if the context is not a record, i.e.. if the anonymous
106 /// struct/union is at namespace or block scope.
108 /// FIXME: This is needed by ASTImporter and ASTStructureEquivalence. It
109 /// probably makes more sense in some other common place then here.
110 static llvm::Optional<unsigned>
111 findUntaggedStructOrUnionIndex(RecordDecl *Anon);
113 // If ErrorOnTagTypeMismatch is set, return the the error, otherwise get the
114 // relevant warning for the input error diagnostic.
115 unsigned getApplicableDiagnostic(unsigned ErrorDiagnostic);
118 /// Finish checking all of the structural equivalences.
120 /// \returns true if the equivalence check failed (non-equivalence detected),
121 /// false if equivalence was detected.
124 /// Check for common properties at Finish.
125 /// \returns true if D1 and D2 may be equivalent,
126 /// false if they are for sure not.
127 bool CheckCommonEquivalence(Decl *D1, Decl *D2);
129 /// Check for class dependent properties at Finish.
130 /// \returns true if D1 and D2 may be equivalent,
131 /// false if they are for sure not.
132 bool CheckKindSpecificEquivalence(Decl *D1, Decl *D2);
137 #endif // LLVM_CLANG_AST_ASTSTRUCTURALEQUIVALENCE_H