clang 10.0.0git

EvaluatedExprVisitor.h
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1 //===--- EvaluatedExprVisitor.h - Evaluated expression visitor --*- 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 // This file defines the EvaluatedExprVisitor class template, which visits
10 // the potentially-evaluated subexpressions of a potentially-evaluated
11 // expression.
12 //
13 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
15 #define LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
16
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/StmtVisitor.h"
21 #include "llvm/ADT/STLExtras.h"
22
23 namespace clang {
24
25 class ASTContext;
26
27 /// Given a potentially-evaluated expression, this visitor visits all
28 /// of its potentially-evaluated subexpressions, recursively.
29 template<template <typename> class Ptr, typename ImplClass>
30 class EvaluatedExprVisitorBase : public StmtVisitorBase<Ptr, ImplClass, void> {
31 protected:
32 const ASTContext &Context;
33
34 public:
35 #define PTR(CLASS) typename Ptr<CLASS>::type
36
37 explicit EvaluatedExprVisitorBase(const ASTContext &Context) : Context(Context) { }
38
39 // Expressions that have no potentially-evaluated subexpressions (but may have
40 // other sub-expressions).
41 void VisitDeclRefExpr(PTR(DeclRefExpr) E) { }
42 void VisitOffsetOfExpr(PTR(OffsetOfExpr) E) { }
43 void VisitUnaryExprOrTypeTraitExpr(PTR(UnaryExprOrTypeTraitExpr) E) { }
44 void VisitExpressionTraitExpr(PTR(ExpressionTraitExpr) E) { }
45 void VisitBlockExpr(PTR(BlockExpr) E) { }
46 void VisitCXXUuidofExpr(PTR(CXXUuidofExpr) E) { }
47 void VisitCXXNoexceptExpr(PTR(CXXNoexceptExpr) E) { }
48
49 void VisitMemberExpr(PTR(MemberExpr) E) {
50 // Only the base matters.
51 return this->Visit(E->getBase());
52 }
53
54 void VisitChooseExpr(PTR(ChooseExpr) E) {
55 // Don't visit either child expression if the condition is dependent.
56 if (E->getCond()->isValueDependent())
57 return;
58 // Only the selected subexpression matters; the other one is not evaluated.
59 return this->Visit(E->getChosenSubExpr());
60 }
61
62 void VisitGenericSelectionExpr(PTR(GenericSelectionExpr) E) {
63 // The controlling expression of a generic selection is not evaluated.
64
65 // Don't visit either child expression if the condition is type-dependent.
66 if (E->isResultDependent())
67 return;
68 // Only the selected subexpression matters; the other subexpressions and the
69 // controlling expression are not evaluated.
70 return this->Visit(E->getResultExpr());
71 }
72
73 void VisitDesignatedInitExpr(PTR(DesignatedInitExpr) E) {
74 // Only the actual initializer matters; the designators are all constant
75 // expressions.
76 return this->Visit(E->getInit());
77 }
78
79 void VisitCXXTypeidExpr(PTR(CXXTypeidExpr) E) {
80 if (E->isPotentiallyEvaluated())
81 return this->Visit(E->getExprOperand());
82 }
83
84 void VisitCallExpr(PTR(CallExpr) CE) {
85 if (!CE->isUnevaluatedBuiltinCall(Context))
86 return static_cast<ImplClass*>(this)->VisitExpr(CE);
87 }
88
89 void VisitLambdaExpr(PTR(LambdaExpr) LE) {
90 // Only visit the capture initializers, and not the body.
91 for (LambdaExpr::const_capture_init_iterator I = LE->capture_init_begin(),
92 E = LE->capture_init_end();
93 I != E; ++I)
94 if (*I)
95 this->Visit(*I);
96 }
97
98 /// The basis case walks all of the children of the statement or
99 /// expression, assuming they are all potentially evaluated.
100 void VisitStmt(PTR(Stmt) S) {
101 for (auto *SubStmt : S->children())
102 if (SubStmt)
103 this->Visit(SubStmt);
104 }
105
106 #undef PTR
107 };
108
109 /// EvaluatedExprVisitor - This class visits 'Expr *'s
110 template <typename ImplClass>
111 class EvaluatedExprVisitor
112 : public EvaluatedExprVisitorBase<std::add_pointer, ImplClass> {
113 public:
114 explicit EvaluatedExprVisitor(const ASTContext &Context)
115 : EvaluatedExprVisitorBase<std::add_pointer, ImplClass>(Context) {}
116 };
117
118 /// ConstEvaluatedExprVisitor - This class visits 'const Expr *'s.
119 template <typename ImplClass>
120 class ConstEvaluatedExprVisitor
121 : public EvaluatedExprVisitorBase<llvm::make_const_ptr, ImplClass> {
122 public:
123 explicit ConstEvaluatedExprVisitor(const ASTContext &Context)
124 : EvaluatedExprVisitorBase<llvm::make_const_ptr, ImplClass>(Context) {}
125 };
126 }
127
128 #endif // LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
clang::EvaluatedExprVisitorBase::Context
const ASTContext & Context
Definition: EvaluatedExprVisitor.h:32
clang::ChooseExpr::getChosenSubExpr
Expr * getChosenSubExpr() const
getChosenSubExpr - Return the subexpression chosen according to the condition.
Definition: Expr.h:4171
clang::EvaluatedExprVisitor
EvaluatedExprVisitor - This class visits &#39;Expr *&#39;s.
Definition: EvaluatedExprVisitor.h:111
clang::ChooseExpr::getCond
Expr * getCond() const
Definition: Expr.h:4175
clang::GenericSelectionExpr::getResultExpr
Expr * getResultExpr()
Return the result expression of this controlling expression.
Definition: Expr.h:5426
llvm
Specialize PointerLikeTypeTraits to allow LazyGenerationalUpdatePtr to be placed into a PointerUnion...
Definition: Dominators.h:30
clang::Stmt
Stmt - This represents one statement.
Definition: Stmt.h:66
clang::MemberExpr::getBase
Expr * getBase() const
Definition: Expr.h:2913
PTR
#define PTR(CLASS)
Definition: EvaluatedExprVisitor.h:35
clang::CXXTypeidExpr::getExprOperand
Expr * getExprOperand() const
Definition: ExprCXX.h:821
ExprCXX.h
Defines the clang::Expr interface and subclasses for C++ expressions.
clang::EvaluatedExprVisitorBase::VisitDesignatedInitExpr
void VisitDesignatedInitExpr(PTR(DesignatedInitExpr) E)
Definition: EvaluatedExprVisitor.h:73
clang::DesignatedInitExpr
Represents a C99 designated initializer expression.
Definition: Expr.h:4639
clang::ASTContext
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:168
clang::DesignatedInitExpr::getInit
Expr * getInit() const
Retrieve the initializer value.
Definition: Expr.h:4877
std
Definition: Format.h:2445
clang::CXXTypeidExpr
A C++ typeid expression (C++ [expr.typeid]), which gets the type_info that corresponds to the supplie...
Definition: ExprCXX.h:764
clang::EvaluatedExprVisitorBase::VisitBlockExpr
void VisitBlockExpr(PTR(BlockExpr) E)
Definition: EvaluatedExprVisitor.h:45
clang::LambdaExpr::capture_init_begin
capture_init_iterator capture_init_begin()
Retrieve the first initialization argument for this lambda expression (which initializes the first ca...
Definition: ExprCXX.h:1963
clang::Stmt::children
child_range children()
Definition: Stmt.cpp:224
clang::LambdaExpr
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1818
clang::CallExpr::isUnevaluatedBuiltinCall
bool isUnevaluatedBuiltinCall(const ASTContext &Ctx) const
Returns true if this is a call to a builtin which does not evaluate side-effects within its arguments...
Definition: Expr.cpp:1493
clang::EvaluatedExprVisitor::EvaluatedExprVisitor
EvaluatedExprVisitor(const ASTContext &Context)
Definition: EvaluatedExprVisitor.h:114
clang::UnaryExprOrTypeTraitExpr
UnaryExprOrTypeTraitExpr - expression with either a type or (unevaluated) expression operand...
Definition: Expr.h:2372
clang::EvaluatedExprVisitorBase::EvaluatedExprVisitorBase
EvaluatedExprVisitorBase(const ASTContext &Context)
Definition: EvaluatedExprVisitor.h:37
clang::EvaluatedExprVisitorBase::VisitGenericSelectionExpr
void VisitGenericSelectionExpr(PTR(GenericSelectionExpr) E)
Definition: EvaluatedExprVisitor.h:62
clang::BlockExpr
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5579
clang::ConstEvaluatedExprVisitor::ConstEvaluatedExprVisitor
ConstEvaluatedExprVisitor(const ASTContext &Context)
Definition: EvaluatedExprVisitor.h:123
StmtVisitor.h
clang::EvaluatedExprVisitorBase::VisitCXXTypeidExpr
void VisitCXXTypeidExpr(PTR(CXXTypeidExpr) E)
Definition: EvaluatedExprVisitor.h:79
clang::EvaluatedExprVisitorBase::VisitCallExpr
void VisitCallExpr(PTR(CallExpr) CE)
Definition: EvaluatedExprVisitor.h:84
clang::EvaluatedExprVisitorBase::VisitDeclRefExpr
void VisitDeclRefExpr(PTR(DeclRefExpr) E)
Definition: EvaluatedExprVisitor.h:41
clang::EvaluatedExprVisitorBase::VisitExpressionTraitExpr
void VisitExpressionTraitExpr(PTR(ExpressionTraitExpr) E)
Definition: EvaluatedExprVisitor.h:44
clang::EvaluatedExprVisitorBase::VisitLambdaExpr
void VisitLambdaExpr(PTR(LambdaExpr) LE)
Definition: EvaluatedExprVisitor.h:89
clang::Expr::isValueDependent
bool isValueDependent() const
isValueDependent - Determines whether this expression is value-dependent (C++ [temp.dep.constexpr]).
Definition: Expr.h:158
clang::EvaluatedExprVisitorBase::VisitCXXNoexceptExpr
void VisitCXXNoexceptExpr(PTR(CXXNoexceptExpr) E)
Definition: EvaluatedExprVisitor.h:47
clang::ExpressionTraitExpr
An expression trait intrinsic.
Definition: ExprCXX.h:2785
clang::GenericSelectionExpr
Represents a C11 generic selection.
Definition: Expr.h:5234
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:21
clang::EvaluatedExprVisitorBase::VisitUnaryExprOrTypeTraitExpr
void VisitUnaryExprOrTypeTraitExpr(PTR(UnaryExprOrTypeTraitExpr) E)
Definition: EvaluatedExprVisitor.h:43
clang::GenericSelectionExpr::isResultDependent
bool isResultDependent() const
Whether this generic selection is result-dependent.
Definition: Expr.h:5414
clang::ConstEvaluatedExprVisitor
ConstEvaluatedExprVisitor - This class visits &#39;const Expr *&#39;s.
Definition: EvaluatedExprVisitor.h:120
clang::EvaluatedExprVisitorBase::VisitCXXUuidofExpr
void VisitCXXUuidofExpr(PTR(CXXUuidofExpr) E)
Definition: EvaluatedExprVisitor.h:46
clang::CXXNoexceptExpr
Represents a C++11 noexcept expression (C++ [expr.unary.noexcept]).
Definition: ExprCXX.h:3958
clang::StmtVisitorBase
StmtVisitorBase - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:36
clang::EvaluatedExprVisitorBase
Given a potentially-evaluated expression, this visitor visits all of its potentially-evaluated subexp...
Definition: EvaluatedExprVisitor.h:30
DeclCXX.h
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
clang::MemberExpr
MemberExpr - [C99 6.5.2.3] Structure and Union Members.
Definition: Expr.h:2836
clang::ChooseExpr
ChooseExpr - GNU builtin-in function __builtin_choose_expr.
Definition: Expr.h:4130
clang::interp::LE
bool LE(InterpState &S, CodePtr OpPC)
Definition: Interp.h:237
clang::EvaluatedExprVisitorBase::VisitMemberExpr
void VisitMemberExpr(PTR(MemberExpr) E)
Definition: EvaluatedExprVisitor.h:49
Expr.h
clang::CallExpr
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2546
clang::StmtVisitorBase< Ptr, ImplClass, void >::Visit
void Visit(PTR(Stmt) S, ParamTys... P)
Definition: StmtVisitor.h:43
clang::EvaluatedExprVisitorBase::VisitChooseExpr
void VisitChooseExpr(PTR(ChooseExpr) E)
Definition: EvaluatedExprVisitor.h:54
clang::LambdaExpr::capture_init_end
capture_init_iterator capture_init_end()
Retrieve the iterator pointing one past the last initialization argument for this lambda expression...
Definition: ExprCXX.h:1975
clang::DeclRefExpr
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1171
clang::LambdaExpr::const_capture_init_iterator
Expr *const * const_capture_init_iterator
Const iterator that walks over the capture initialization arguments.
Definition: ExprCXX.h:1949
clang::OffsetOfExpr
OffsetOfExpr - [C99 7.17] - This represents an expression of the form offsetof(record-type, member-designator).
Definition: Expr.h:2267
clang::CXXUuidofExpr
A Microsoft C++ __uuidof expression, which gets the _GUID that corresponds to the supplied type or ex...
Definition: ExprCXX.h:1000
clang::CXXTypeidExpr::isPotentiallyEvaluated
bool isPotentiallyEvaluated() const
Determine whether this typeid has a type operand which is potentially evaluated, per C++11 [expr...
Definition: ExprCXX.cpp:132
clang::EvaluatedExprVisitorBase::VisitOffsetOfExpr
void VisitOffsetOfExpr(PTR(OffsetOfExpr) E)
Definition: EvaluatedExprVisitor.h:42
clang::EvaluatedExprVisitorBase::VisitStmt
void VisitStmt(PTR(Stmt) S)
The basis case walks all of the children of the statement or expression, assuming they are all potent...
Definition: EvaluatedExprVisitor.h:100