Clang Project

clang_source_code/include/clang/AST/DeclContextInternals.h
1//===- DeclContextInternals.h - DeclContext Representation ------*- 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 data structures used in the implementation
10//  of DeclContext.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_DECLCONTEXTINTERNALS_H
15#define LLVM_CLANG_AST_DECLCONTEXTINTERNALS_H
16
17#include "clang/AST/Decl.h"
18#include "clang/AST/DeclBase.h"
19#include "clang/AST/DeclCXX.h"
20#include "clang/AST/DeclarationName.h"
21#include "llvm/ADT/DenseMap.h"
22#include "llvm/ADT/PointerIntPair.h"
23#include "llvm/ADT/PointerUnion.h"
24#include "llvm/ADT/SmallVector.h"
25#include <algorithm>
26#include <cassert>
27
28namespace clang {
29
30class DependentDiagnostic;
31
32/// An array of decls optimized for the common case of only containing
33/// one entry.
34struct StoredDeclsList {
35  /// When in vector form, this is what the Data pointer points to.
36  using DeclsTy = SmallVector<NamedDecl *, 4>;
37
38  /// A collection of declarations, with a flag to indicate if we have
39  /// further external declarations.
40  using DeclsAndHasExternalTy = llvm::PointerIntPair<DeclsTy *, 1, bool>;
41
42  /// The stored data, which will be either a pointer to a NamedDecl,
43  /// or a pointer to a vector with a flag to indicate if there are further
44  /// external declarations.
45  llvm::PointerUnion<NamedDecl *, DeclsAndHasExternalTy> Data;
46
47public:
48  StoredDeclsList() = default;
49
50  StoredDeclsList(StoredDeclsList &&RHS) : Data(RHS.Data) {
51    RHS.Data = (NamedDecl *)nullptr;
52  }
53
54  ~StoredDeclsList() {
55    // If this is a vector-form, free the vector.
56    if (DeclsTy *Vector = getAsVector())
57      delete Vector;
58  }
59
60  StoredDeclsList &operator=(StoredDeclsList &&RHS) {
61    if (DeclsTy *Vector = getAsVector())
62      delete Vector;
63    Data = RHS.Data;
64    RHS.Data = (NamedDecl *)nullptr;
65    return *this;
66  }
67
68  bool isNull() const { return Data.isNull(); }
69
70  NamedDecl *getAsDecl() const {
71    return Data.dyn_cast<NamedDecl *>();
72  }
73
74  DeclsAndHasExternalTy getAsVectorAndHasExternal() const {
75    return Data.dyn_cast<DeclsAndHasExternalTy>();
76  }
77
78  DeclsTy *getAsVector() const {
79    return getAsVectorAndHasExternal().getPointer();
80  }
81
82  bool hasExternalDecls() const {
83    return getAsVectorAndHasExternal().getInt();
84  }
85
86  void setHasExternalDecls() {
87    if (DeclsTy *Vec = getAsVector())
88      Data = DeclsAndHasExternalTy(Vec, true);
89    else {
90      DeclsTy *VT = new DeclsTy();
91      if (NamedDecl *OldD = getAsDecl())
92        VT->push_back(OldD);
93      Data = DeclsAndHasExternalTy(VT, true);
94    }
95  }
96
97  void setOnlyValue(NamedDecl *ND) {
98     (0) . __assert_fail ("!getAsVector() && \"Not inline\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 98, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!getAsVector() && "Not inline");
99    Data = ND;
100    // Make sure that Data is a plain NamedDecl* so we can use its address
101    // at getLookupResult.
102     (0) . __assert_fail ("*(NamedDecl **)&Data == ND && \"PointerUnion mangles the NamedDecl pointer!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 103, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(*(NamedDecl **)&Data == ND &&
103 (0) . __assert_fail ("*(NamedDecl **)&Data == ND && \"PointerUnion mangles the NamedDecl pointer!\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 103, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">           "PointerUnion mangles the NamedDecl pointer!");
104  }
105
106  void remove(NamedDecl *D) {
107     (0) . __assert_fail ("!isNull() && \"removing from empty list\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 107, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isNull() && "removing from empty list");
108    if (NamedDecl *Singleton = getAsDecl()) {
109       (0) . __assert_fail ("Singleton == D && \"list is different singleton\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 109, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(Singleton == D && "list is different singleton");
110      (void)Singleton;
111      Data = (NamedDecl *)nullptr;
112      return;
113    }
114
115    DeclsTy &Vec = *getAsVector();
116    DeclsTy::iterator I = std::find(Vec.begin(), Vec.end(), D);
117     (0) . __assert_fail ("I != Vec.end() && \"list does not contain decl\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 117, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(I != Vec.end() && "list does not contain decl");
118    Vec.erase(I);
119
120     (0) . __assert_fail ("std..find(Vec.begin(), Vec.end(), D) == Vec.end() && \"list still contains decl\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 121, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(std::find(Vec.begin(), Vec.end(), D)
121 (0) . __assert_fail ("std..find(Vec.begin(), Vec.end(), D) == Vec.end() && \"list still contains decl\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 121, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">             == Vec.end() && "list still contains decl");
122  }
123
124  /// Remove any declarations which were imported from an external
125  /// AST source.
126  void removeExternalDecls() {
127    if (isNull()) {
128      // Nothing to do.
129    } else if (NamedDecl *Singleton = getAsDecl()) {
130      if (Singleton->isFromASTFile())
131        *this = StoredDeclsList();
132    } else {
133      DeclsTy &Vec = *getAsVector();
134      Vec.erase(std::remove_if(Vec.begin(), Vec.end(),
135                               [](Decl *D) { return D->isFromASTFile(); }),
136                Vec.end());
137      // Don't have any external decls any more.
138      Data = DeclsAndHasExternalTy(&Vec, false);
139    }
140  }
141
142  /// getLookupResult - Return an array of all the decls that this list
143  /// represents.
144  DeclContext::lookup_result getLookupResult() {
145    if (isNull())
146      return DeclContext::lookup_result();
147
148    // If we have a single NamedDecl, return it.
149    if (NamedDecl *ND = getAsDecl()) {
150       (0) . __assert_fail ("!isNull() && \"Empty list isn't allowed\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 150, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isNull() && "Empty list isn't allowed");
151
152      // Data is a raw pointer to a NamedDecl*, return it.
153      return DeclContext::lookup_result(ND);
154    }
155
156     (0) . __assert_fail ("getAsVector() && \"Must have a vector at this point\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 156, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(getAsVector() && "Must have a vector at this point");
157    DeclsTy &Vector = *getAsVector();
158
159    // Otherwise, we have a range result.
160    return DeclContext::lookup_result(Vector);
161  }
162
163  /// HandleRedeclaration - If this is a redeclaration of an existing decl,
164  /// replace the old one with D and return true.  Otherwise return false.
165  bool HandleRedeclaration(NamedDecl *D, bool IsKnownNewer) {
166    // Most decls only have one entry in their list, special case it.
167    if (NamedDecl *OldD = getAsDecl()) {
168      if (!D->declarationReplaces(OldD, IsKnownNewer))
169        return false;
170      setOnlyValue(D);
171      return true;
172    }
173
174    // Determine if this declaration is actually a redeclaration.
175    DeclsTy &Vec = *getAsVector();
176    for (DeclsTy::iterator OD = Vec.begin(), ODEnd = Vec.end();
177         OD != ODEnd; ++OD) {
178      NamedDecl *OldD = *OD;
179      if (D->declarationReplaces(OldD, IsKnownNewer)) {
180        *OD = D;
181        return true;
182      }
183    }
184
185    return false;
186  }
187
188  /// AddSubsequentDecl - This is called on the second and later decl when it is
189  /// not a redeclaration to merge it into the appropriate place in our list.
190  void AddSubsequentDecl(NamedDecl *D) {
191     (0) . __assert_fail ("!isNull() && \"don't AddSubsequentDecl when we have no decls\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclContextInternals.h", 191, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!isNull() && "don't AddSubsequentDecl when we have no decls");
192
193    // If this is the second decl added to the list, convert this to vector
194    // form.
195    if (NamedDecl *OldD = getAsDecl()) {
196      DeclsTy *VT = new DeclsTy();
197      VT->push_back(OldD);
198      Data = DeclsAndHasExternalTy(VT, false);
199    }
200
201    DeclsTy &Vec = *getAsVector();
202
203    // Using directives end up in a special entry which contains only
204    // other using directives, so all this logic is wasted for them.
205    // But avoiding the logic wastes time in the far-more-common case
206    // that we're *not* adding a new using directive.
207
208    // Tag declarations always go at the end of the list so that an
209    // iterator which points at the first tag will start a span of
210    // decls that only contains tags.
211    if (D->hasTagIdentifierNamespace())
212      Vec.push_back(D);
213
214    // Resolved using declarations go at the front of the list so that
215    // they won't show up in other lookup results.  Unresolved using
216    // declarations (which are always in IDNS_Using | IDNS_Ordinary)
217    // follow that so that the using declarations will be contiguous.
218    else if (D->getIdentifierNamespace() & Decl::IDNS_Using) {
219      DeclsTy::iterator I = Vec.begin();
220      if (D->getIdentifierNamespace() != Decl::IDNS_Using) {
221        while (I != Vec.end() &&
222               (*I)->getIdentifierNamespace() == Decl::IDNS_Using)
223          ++I;
224      }
225      Vec.insert(I, D);
226
227    // All other declarations go at the end of the list, but before any
228    // tag declarations.  But we can be clever about tag declarations
229    // because there can only ever be one in a scope.
230    } else if (!Vec.empty() && Vec.back()->hasTagIdentifierNamespace()) {
231      NamedDecl *TagD = Vec.back();
232      Vec.back() = D;
233      Vec.push_back(TagD);
234    } else
235      Vec.push_back(D);
236  }
237};
238
239class StoredDeclsMap
240    : public llvm::SmallDenseMap<DeclarationName, StoredDeclsList, 4> {
241public:
242  static void DestroyAll(StoredDeclsMap *Map, bool Dependent);
243
244private:
245  friend class ASTContext; // walks the chain deleting these
246  friend class DeclContext;
247
248  llvm::PointerIntPair<StoredDeclsMap*, 1> Previous;
249};
250
251class DependentStoredDeclsMap : public StoredDeclsMap {
252public:
253  DependentStoredDeclsMap() = default;
254
255private:
256  friend class DeclContext; // iterates over diagnostics
257  friend class DependentDiagnostic;
258
259  DependentDiagnostic *FirstDiagnostic = nullptr;
260};
261
262} // namespace clang
263
264#endif // LLVM_CLANG_AST_DECLCONTEXTINTERNALS_H
265
clang::StoredDeclsList::Data
clang::StoredDeclsList::isNull
clang::StoredDeclsList::getAsDecl
clang::StoredDeclsList::getAsVectorAndHasExternal
clang::StoredDeclsList::getAsVector
clang::StoredDeclsList::hasExternalDecls
clang::StoredDeclsList::setHasExternalDecls
clang::StoredDeclsList::setOnlyValue
clang::StoredDeclsList::remove
clang::StoredDeclsList::removeExternalDecls
clang::StoredDeclsList::getLookupResult
clang::StoredDeclsList::HandleRedeclaration
clang::StoredDeclsList::AddSubsequentDecl
clang::StoredDeclsMap::DestroyAll
clang::StoredDeclsMap::Previous
clang::DependentStoredDeclsMap::FirstDiagnostic
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