xref: /freebsd/contrib/llvm-project/clang/lib/AST/ExprConcepts.cpp (revision 1ac55f4cb0001fed92329746c730aa9a947c09a5)
1 //===- ExprCXX.cpp - (C++) Expression AST Node Implementation -------------===//
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 // This file implements the subclesses of Expr class declared in ExprCXX.h
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/ExprConcepts.h"
14 #include "clang/AST/ASTConcept.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ComputeDependence.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclTemplate.h"
19 #include "clang/AST/DeclarationName.h"
20 #include "clang/AST/DependenceFlags.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/AST/NestedNameSpecifier.h"
23 #include "clang/AST/TemplateBase.h"
24 #include "clang/AST/Type.h"
25 #include "clang/Basic/SourceLocation.h"
26 #include "llvm/Support/TrailingObjects.h"
27 #include <algorithm>
28 #include <string>
29 #include <utility>
30 
31 using namespace clang;
32 
33 ConceptSpecializationExpr::ConceptSpecializationExpr(
34     const ASTContext &C, NestedNameSpecifierLoc NNS,
35     SourceLocation TemplateKWLoc, DeclarationNameInfo ConceptNameInfo,
36     NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
37     const ASTTemplateArgumentListInfo *ArgsAsWritten,
38     ImplicitConceptSpecializationDecl *SpecDecl,
39     const ConstraintSatisfaction *Satisfaction)
40     : Expr(ConceptSpecializationExprClass, C.BoolTy, VK_PRValue, OK_Ordinary),
41       ConceptReference(NNS, TemplateKWLoc, ConceptNameInfo, FoundDecl,
42                        NamedConcept, ArgsAsWritten),
43       SpecDecl(SpecDecl),
44       Satisfaction(Satisfaction
45                        ? ASTConstraintSatisfaction::Create(C, *Satisfaction)
46                        : nullptr) {
47   setDependence(computeDependence(this, /*ValueDependent=*/!Satisfaction));
48 
49   // Currently guaranteed by the fact concepts can only be at namespace-scope.
50   assert(!NestedNameSpec ||
51          (!NestedNameSpec.getNestedNameSpecifier()->isInstantiationDependent() &&
52           !NestedNameSpec.getNestedNameSpecifier()
53               ->containsUnexpandedParameterPack()));
54   assert((!isValueDependent() || isInstantiationDependent()) &&
55          "should not be value-dependent");
56 }
57 
58 ConceptSpecializationExpr::ConceptSpecializationExpr(EmptyShell Empty)
59     : Expr(ConceptSpecializationExprClass, Empty) {}
60 
61 ConceptSpecializationExpr *ConceptSpecializationExpr::Create(
62     const ASTContext &C, NestedNameSpecifierLoc NNS,
63     SourceLocation TemplateKWLoc, DeclarationNameInfo ConceptNameInfo,
64     NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
65     const ASTTemplateArgumentListInfo *ArgsAsWritten,
66     ImplicitConceptSpecializationDecl *SpecDecl,
67     const ConstraintSatisfaction *Satisfaction) {
68   return new (C) ConceptSpecializationExpr(
69       C, NNS, TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
70       ArgsAsWritten, SpecDecl, Satisfaction);
71 }
72 
73 ConceptSpecializationExpr::ConceptSpecializationExpr(
74     const ASTContext &C, ConceptDecl *NamedConcept,
75     ImplicitConceptSpecializationDecl *SpecDecl,
76     const ConstraintSatisfaction *Satisfaction, bool Dependent,
77     bool ContainsUnexpandedParameterPack)
78     : Expr(ConceptSpecializationExprClass, C.BoolTy, VK_PRValue, OK_Ordinary),
79       ConceptReference(NestedNameSpecifierLoc(), SourceLocation(),
80                        DeclarationNameInfo(), NamedConcept, NamedConcept,
81                        nullptr),
82       SpecDecl(SpecDecl),
83       Satisfaction(Satisfaction
84                        ? ASTConstraintSatisfaction::Create(C, *Satisfaction)
85                        : nullptr) {
86   ExprDependence D = ExprDependence::None;
87   if (!Satisfaction)
88     D |= ExprDependence::Value;
89   if (Dependent)
90     D |= ExprDependence::Instantiation;
91   if (ContainsUnexpandedParameterPack)
92     D |= ExprDependence::UnexpandedPack;
93   setDependence(D);
94 }
95 
96 ConceptSpecializationExpr *ConceptSpecializationExpr::Create(
97     const ASTContext &C, ConceptDecl *NamedConcept,
98     ImplicitConceptSpecializationDecl *SpecDecl,
99     const ConstraintSatisfaction *Satisfaction, bool Dependent,
100     bool ContainsUnexpandedParameterPack) {
101   return new (C)
102       ConceptSpecializationExpr(C, NamedConcept, SpecDecl, Satisfaction,
103                                 Dependent, ContainsUnexpandedParameterPack);
104 }
105 
106 const TypeConstraint *
107 concepts::ExprRequirement::ReturnTypeRequirement::getTypeConstraint() const {
108   assert(isTypeConstraint());
109   auto TPL =
110       TypeConstraintInfo.getPointer().get<TemplateParameterList *>();
111   return cast<TemplateTypeParmDecl>(TPL->getParam(0))
112       ->getTypeConstraint();
113 }
114 
115 RequiresExpr::RequiresExpr(ASTContext &C, SourceLocation RequiresKWLoc,
116                            RequiresExprBodyDecl *Body,
117                            ArrayRef<ParmVarDecl *> LocalParameters,
118                            ArrayRef<concepts::Requirement *> Requirements,
119                            SourceLocation RBraceLoc)
120     : Expr(RequiresExprClass, C.BoolTy, VK_PRValue, OK_Ordinary),
121       NumLocalParameters(LocalParameters.size()),
122       NumRequirements(Requirements.size()), Body(Body), RBraceLoc(RBraceLoc) {
123   RequiresExprBits.IsSatisfied = false;
124   RequiresExprBits.RequiresKWLoc = RequiresKWLoc;
125   bool Dependent = false;
126   bool ContainsUnexpandedParameterPack = false;
127   for (ParmVarDecl *P : LocalParameters) {
128     Dependent |= P->getType()->isInstantiationDependentType();
129     ContainsUnexpandedParameterPack |=
130         P->getType()->containsUnexpandedParameterPack();
131   }
132   RequiresExprBits.IsSatisfied = true;
133   for (concepts::Requirement *R : Requirements) {
134     Dependent |= R->isDependent();
135     ContainsUnexpandedParameterPack |= R->containsUnexpandedParameterPack();
136     if (!Dependent) {
137       RequiresExprBits.IsSatisfied = R->isSatisfied();
138       if (!RequiresExprBits.IsSatisfied)
139         break;
140     }
141   }
142   std::copy(LocalParameters.begin(), LocalParameters.end(),
143             getTrailingObjects<ParmVarDecl *>());
144   std::copy(Requirements.begin(), Requirements.end(),
145             getTrailingObjects<concepts::Requirement *>());
146   RequiresExprBits.IsSatisfied |= Dependent;
147   // FIXME: move the computing dependency logic to ComputeDependence.h
148   if (ContainsUnexpandedParameterPack)
149     setDependence(getDependence() | ExprDependence::UnexpandedPack);
150   // FIXME: this is incorrect for cases where we have a non-dependent
151   // requirement, but its parameters are instantiation-dependent. RequiresExpr
152   // should be instantiation-dependent if it has instantiation-dependent
153   // parameters.
154   if (Dependent)
155     setDependence(getDependence() | ExprDependence::ValueInstantiation);
156 }
157 
158 RequiresExpr::RequiresExpr(ASTContext &C, EmptyShell Empty,
159                            unsigned NumLocalParameters,
160                            unsigned NumRequirements)
161   : Expr(RequiresExprClass, Empty), NumLocalParameters(NumLocalParameters),
162     NumRequirements(NumRequirements) { }
163 
164 RequiresExpr *
165 RequiresExpr::Create(ASTContext &C, SourceLocation RequiresKWLoc,
166                      RequiresExprBodyDecl *Body,
167                      ArrayRef<ParmVarDecl *> LocalParameters,
168                      ArrayRef<concepts::Requirement *> Requirements,
169                      SourceLocation RBraceLoc) {
170   void *Mem =
171       C.Allocate(totalSizeToAlloc<ParmVarDecl *, concepts::Requirement *>(
172                      LocalParameters.size(), Requirements.size()),
173                  alignof(RequiresExpr));
174   return new (Mem) RequiresExpr(C, RequiresKWLoc, Body, LocalParameters,
175                                 Requirements, RBraceLoc);
176 }
177 
178 RequiresExpr *
179 RequiresExpr::Create(ASTContext &C, EmptyShell Empty,
180                      unsigned NumLocalParameters, unsigned NumRequirements) {
181   void *Mem =
182       C.Allocate(totalSizeToAlloc<ParmVarDecl *, concepts::Requirement *>(
183                      NumLocalParameters, NumRequirements),
184                  alignof(RequiresExpr));
185   return new (Mem) RequiresExpr(C, Empty, NumLocalParameters, NumRequirements);
186 }
187