clang
20.0.0git
include
clang
AST
ASTImporterLookupTable.h
Go to the documentation of this file.
1
//===- ASTImporterLookupTable.h - ASTImporter specific lookup--*- 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 ASTImporterLookupTable class which implements a
10
// lookup procedure for the import mechanism.
11
//
12
//===----------------------------------------------------------------------===//
13
14
#ifndef LLVM_CLANG_AST_ASTIMPORTERLOOKUPTABLE_H
15
#define LLVM_CLANG_AST_ASTIMPORTERLOOKUPTABLE_H
16
17
#include "
clang/AST/DeclBase.h
"
// lookup_result
18
#include "
clang/AST/DeclarationName.h
"
19
#include "llvm/ADT/DenseMap.h"
20
#include "llvm/ADT/SetVector.h"
21
22
namespace
clang
{
23
24
class
NamedDecl;
25
class
DeclContext;
26
27
// There are certain cases when normal C/C++ lookup (localUncachedLookup)
28
// does not find AST nodes. E.g.:
29
// Example 1:
30
// template <class T>
31
// struct X {
32
// friend void foo(); // this is never found in the DC of the TU.
33
// };
34
// Example 2:
35
// // The fwd decl to Foo is not found in the lookupPtr of the DC of the
36
// // translation unit decl.
37
// // Here we could find the node by doing a traverse throught the list of
38
// // the Decls in the DC, but that would not scale.
39
// struct A { struct Foo *p; };
40
// This is a severe problem because the importer decides if it has to create a
41
// new Decl or not based on the lookup results.
42
// To overcome these cases we need an importer specific lookup table which
43
// holds every node and we are not interested in any C/C++ specific visibility
44
// considerations. Simply, we must know if there is an existing Decl in a
45
// given DC. Once we found it then we can handle any visibility related tasks.
46
class
ASTImporterLookupTable
{
47
48
// We store a list of declarations for each name.
49
// And we collect these lists for each DeclContext.
50
// We could have a flat map with (DeclContext, Name) tuple as key, but a two
51
// level map seems easier to handle.
52
using
DeclList
=
llvm::SmallSetVector<NamedDecl *, 2>
;
53
using
NameMap = llvm::SmallDenseMap<DeclarationName, DeclList, 4>;
54
using
DCMap = llvm::DenseMap<DeclContext *, NameMap>;
55
56
void
add(
DeclContext
*DC,
NamedDecl
*ND);
57
void
remove(
DeclContext
*DC,
NamedDecl
*ND);
58
59
DCMap LookupTable;
60
61
public
:
62
ASTImporterLookupTable
(
TranslationUnitDecl
&TU);
63
void
add(
NamedDecl
*ND);
64
void
remove(
NamedDecl
*ND);
65
// Sometimes a declaration is created first with a temporarily value of decl
66
// context (often the translation unit) and later moved to the final context.
67
// This happens for declarations that are created before the final declaration
68
// context. In such cases the lookup table needs to be updated.
69
// (The declaration is in these cases not added to the temporary decl context,
70
// only its parent is set.)
71
// FIXME: It would be better to not add the declaration to the temporary
72
// context at all in the lookup table, but this requires big change in
73
// ASTImporter.
74
// The function should be called when the old context is definitely different
75
// from the new.
76
void
update
(
NamedDecl
*ND,
DeclContext
*OldDC);
77
// Same as 'update' but allow if 'ND' is not in the table or the old context
78
// is the same as the new.
79
// FIXME: The old redeclaration context is not handled.
80
void
updateForced
(
NamedDecl
*ND,
DeclContext
*OldDC);
81
using
LookupResult
=
DeclList
;
82
LookupResult
lookup
(
DeclContext
*DC,
DeclarationName
Name)
const
;
83
// Check if the `ND` is within the lookup table (with its current name) in
84
// context `DC`. This is intended for debug purposes when the DeclContext of a
85
// NamedDecl is changed.
86
bool
contains
(
DeclContext
*DC,
NamedDecl
*ND)
const
;
87
void
dump
(
DeclContext
*DC)
const
;
88
void
dump
()
const
;
89
};
90
91
}
// namespace clang
92
93
#endif
// LLVM_CLANG_AST_ASTIMPORTERLOOKUPTABLE_H
DeclBase.h
DeclarationName.h
clang::ASTImporterLookupTable
Definition:
ASTImporterLookupTable.h:46
clang::ASTImporterLookupTable::dump
void dump() const
Definition:
ASTImporterLookupTable.cpp:196
clang::ASTImporterLookupTable::update
void update(NamedDecl *ND, DeclContext *OldDC)
Definition:
ASTImporterLookupTable.cpp:144
clang::ASTImporterLookupTable::lookup
LookupResult lookup(DeclContext *DC, DeclarationName Name) const
Definition:
ASTImporterLookupTable.cpp:163
clang::ASTImporterLookupTable::updateForced
void updateForced(NamedDecl *ND, DeclContext *OldDC)
Definition:
ASTImporterLookupTable.cpp:157
clang::ASTImporterLookupTable::contains
bool contains(DeclContext *DC, NamedDecl *ND) const
Definition:
ASTImporterLookupTable.cpp:176
clang::DeclContext
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition:
DeclBase.h:1436
clang::DeclarationName
The name of a declaration.
Definition:
DeclarationName.h:144
clang::NamedDecl
This represents a decl that may have a name.
Definition:
Decl.h:249
clang::TranslationUnitDecl
The top declaration context.
Definition:
Decl.h:84
llvm::SmallSetVector
Definition:
ExternalSemaSource.h:23
clang
The JSON file list parser is used to communicate input to InstallAPI.
Definition:
CalledOnceCheck.h:17
Generated on Thu Oct 3 2024 12:15:27 for clang by
1.9.6