1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
#pragma once
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif
//===--- LexicallyOrderedRecursiveASTVisitor.h - ----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the LexicallyOrderedRecursiveASTVisitor interface, which
// recursively traverses the entire AST in a lexical order.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_LEXICALLYORDEREDRECURSIVEASTVISITOR_H
#define LLVM_CLANG_AST_LEXICALLYORDEREDRECURSIVEASTVISITOR_H
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/Support/SaveAndRestore.h"
namespace clang {
/// A RecursiveASTVisitor subclass that guarantees that AST traversal is
/// performed in a lexical order (i.e. the order in which declarations are
/// written in the source).
///
/// RecursiveASTVisitor doesn't guarantee lexical ordering because there are
/// some declarations, like Objective-C @implementation declarations
/// that might be represented in the AST differently to how they were written
/// in the source.
/// In particular, Objective-C @implementation declarations may contain
/// non-Objective-C declarations, like functions:
///
/// @implementation MyClass
///
/// - (void) method { }
/// void normalFunction() { }
///
/// @end
///
/// Clang's AST stores these declarations outside of the @implementation
/// declaration, so the example above would be represented using the following
/// AST:
/// |-ObjCImplementationDecl ... MyClass
/// | `-ObjCMethodDecl ... method
/// | ...
/// `-FunctionDecl ... normalFunction
/// ...
///
/// This class ensures that these declarations are traversed before the
/// corresponding TraverseDecl for the @implementation returns. This ensures
/// that the lexical parent relationship between these declarations and the
/// @implementation is preserved while traversing the AST. Note that the
/// current implementation doesn't mix these declarations with the declarations
/// contained in the @implementation, so the traversal of all of the
/// declarations in the @implementation still doesn't follow the lexical order.
template <typename Derived>
class LexicallyOrderedRecursiveASTVisitor
: public RecursiveASTVisitor<Derived> {
using BaseType = RecursiveASTVisitor<Derived>;
public:
LexicallyOrderedRecursiveASTVisitor(const SourceManager &SM) : SM(SM) {}
bool TraverseObjCImplementationDecl(ObjCImplementationDecl *D) {
// Objective-C @implementation declarations should not trigger early exit
// until the additional decls are traversed as their children are not
// lexically ordered.
bool Result = BaseType::TraverseObjCImplementationDecl(D);
return TraverseAdditionalLexicallyNestedDeclarations() ? Result : false;
}
bool TraverseObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
bool Result = BaseType::TraverseObjCCategoryImplDecl(D);
return TraverseAdditionalLexicallyNestedDeclarations() ? Result : false;
}
bool TraverseDeclContextHelper(DeclContext *DC) {
if (!DC)
return true;
for (auto I = DC->decls_begin(), E = DC->decls_end(); I != E;) {
Decl *Child = *I;
if (BaseType::canIgnoreChildDeclWhileTraversingDeclContext(Child)) {
++I;
continue;
}
if (!isa<ObjCImplementationDecl>(Child) &&
!isa<ObjCCategoryImplDecl>(Child)) {
if (!BaseType::getDerived().TraverseDecl(Child))
return false;
++I;
continue;
}
// Gather declarations that follow the Objective-C implementation
// declarations but are lexically contained in the implementation.
LexicallyNestedDeclarations.clear();
for (++I; I != E; ++I) {
Decl *Sibling = *I;
if (!SM.isBeforeInTranslationUnit(Sibling->getBeginLoc(),
Child->getEndLoc()))
break;
if (!BaseType::canIgnoreChildDeclWhileTraversingDeclContext(Sibling))
LexicallyNestedDeclarations.push_back(Sibling);
}
if (!BaseType::getDerived().TraverseDecl(Child))
return false;
}
return true;
}
Stmt::child_range getStmtChildren(Stmt *S) { return S->children(); }
SmallVector<Stmt *, 8> getStmtChildren(CXXOperatorCallExpr *CE) {
SmallVector<Stmt *, 8> Children(CE->children());
bool Swap;
// Switch the operator and the first operand for all infix and postfix
// operations.
switch (CE->getOperator()) {
case OO_Arrow:
case OO_Call:
case OO_Subscript:
Swap = true;
break;
case OO_PlusPlus:
case OO_MinusMinus:
// These are postfix unless there is exactly one argument.
Swap = Children.size() != 2;
break;
default:
Swap = CE->isInfixBinaryOp();
break;
}
if (Swap && Children.size() > 1)
std::swap(Children[0], Children[1]);
return Children;
}
private:
bool TraverseAdditionalLexicallyNestedDeclarations() {
// FIXME: Ideally the gathered declarations and the declarations in the
// @implementation should be mixed and sorted to get a true lexical order,
// but right now we only care about getting the correct lexical parent, so
// we can traverse the gathered nested declarations after the declarations
// in the decl context.
assert(!BaseType::getDerived().shouldTraversePostOrder() &&
"post-order traversal is not supported for lexically ordered "
"recursive ast visitor");
for (Decl *D : LexicallyNestedDeclarations) {
if (!BaseType::getDerived().TraverseDecl(D))
return false;
}
return true;
}
const SourceManager &SM;
llvm::SmallVector<Decl *, 8> LexicallyNestedDeclarations;
};
} // end namespace clang
#endif // LLVM_CLANG_AST_LEXICALLYORDEREDRECURSIVEASTVISITOR_H
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
|
