1 //===--- DirectoryLookup.h - Info for searching for headers -----*- 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 DirectoryLookup interface.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LEX_DIRECTORYLOOKUP_H
14 #define LLVM_CLANG_LEX_DIRECTORYLOOKUP_H
15 
16 #include "clang/Basic/LLVM.h"
17 #include "clang/Basic/FileManager.h"
18 #include "clang/Basic/SourceManager.h"
19 #include "clang/Lex/ModuleMap.h"
20 
21 namespace clang {
22 class HeaderMap;
23 class HeaderSearch;
24 class Module;
25 
26 /// DirectoryLookup - This class represents one entry in the search list that
27 /// specifies the search order for directories in \#include directives.  It
28 /// represents either a directory, a framework, or a headermap.
29 ///
30 class DirectoryLookup {
31 public:
32   enum LookupType_t {
33     LT_NormalDir,
34     LT_Framework,
35     LT_HeaderMap
36   };
37 private:
38   union DLU { // This union is discriminated by isHeaderMap.
39     /// Dir - This is the actual directory that we're referring to for a normal
40     /// directory or a framework.
41     DirectoryEntryRef Dir;
42 
43     /// Map - This is the HeaderMap if this is a headermap lookup.
44     ///
45     const HeaderMap *Map;
46 
47     DLU(DirectoryEntryRef Dir) : Dir(Dir) {}
48     DLU(const HeaderMap *Map) : Map(Map) {}
49   } u;
50 
51   /// DirCharacteristic - The type of directory this is: this is an instance of
52   /// SrcMgr::CharacteristicKind.
53   unsigned DirCharacteristic : 3;
54 
55   /// LookupType - This indicates whether this DirectoryLookup object is a
56   /// normal directory, a framework, or a headermap.
57   unsigned LookupType : 2;
58 
59   /// Whether this is a header map used when building a framework.
60   unsigned IsIndexHeaderMap : 1;
61 
62   /// Whether we've performed an exhaustive search for module maps
63   /// within the subdirectories of this directory.
64   unsigned SearchedAllModuleMaps : 1;
65 
66 public:
67   /// This ctor *does not take ownership* of 'Dir'.
68   DirectoryLookup(DirectoryEntryRef Dir, SrcMgr::CharacteristicKind DT,
69                   bool isFramework)
70       : u(Dir), DirCharacteristic(DT),
71         LookupType(isFramework ? LT_Framework : LT_NormalDir),
72         IsIndexHeaderMap(false), SearchedAllModuleMaps(false) {}
73 
74   /// This ctor *does not take ownership* of 'Map'.
75   DirectoryLookup(const HeaderMap *Map, SrcMgr::CharacteristicKind DT,
76                   bool isIndexHeaderMap)
77       : u(Map), DirCharacteristic(DT), LookupType(LT_HeaderMap),
78         IsIndexHeaderMap(isIndexHeaderMap), SearchedAllModuleMaps(false) {}
79 
80   /// getLookupType - Return the kind of directory lookup that this is: either a
81   /// normal directory, a framework path, or a HeaderMap.
82   LookupType_t getLookupType() const { return (LookupType_t)LookupType; }
83 
84   /// getName - Return the directory or filename corresponding to this lookup
85   /// object.
86   StringRef getName() const;
87 
88   /// getDir - Return the directory that this entry refers to.
89   ///
90   const DirectoryEntry *getDir() const {
91     return isNormalDir() ? &u.Dir.getDirEntry() : nullptr;
92   }
93 
94   OptionalDirectoryEntryRef getDirRef() const {
95     return isNormalDir() ? OptionalDirectoryEntryRef(u.Dir) : std::nullopt;
96   }
97 
98   /// getFrameworkDir - Return the directory that this framework refers to.
99   ///
100   const DirectoryEntry *getFrameworkDir() const {
101     return isFramework() ? &u.Dir.getDirEntry() : nullptr;
102   }
103 
104   OptionalDirectoryEntryRef getFrameworkDirRef() const {
105     return isFramework() ? OptionalDirectoryEntryRef(u.Dir) : std::nullopt;
106   }
107 
108   /// getHeaderMap - Return the directory that this entry refers to.
109   ///
110   const HeaderMap *getHeaderMap() const {
111     return isHeaderMap() ? u.Map : nullptr;
112   }
113 
114   /// isNormalDir - Return true if this is a normal directory, not a header map.
115   bool isNormalDir() const { return getLookupType() == LT_NormalDir; }
116 
117   /// isFramework - True if this is a framework directory.
118   ///
119   bool isFramework() const { return getLookupType() == LT_Framework; }
120 
121   /// isHeaderMap - Return true if this is a header map, not a normal directory.
122   bool isHeaderMap() const { return getLookupType() == LT_HeaderMap; }
123 
124   /// Determine whether we have already searched this entire
125   /// directory for module maps.
126   bool haveSearchedAllModuleMaps() const { return SearchedAllModuleMaps; }
127 
128   /// Specify whether we have already searched all of the subdirectories
129   /// for module maps.
130   void setSearchedAllModuleMaps(bool SAMM) {
131     SearchedAllModuleMaps = SAMM;
132   }
133 
134   /// DirCharacteristic - The type of directory this is, one of the DirType enum
135   /// values.
136   SrcMgr::CharacteristicKind getDirCharacteristic() const {
137     return (SrcMgr::CharacteristicKind)DirCharacteristic;
138   }
139 
140   /// Whether this describes a system header directory.
141   bool isSystemHeaderDirectory() const {
142     return getDirCharacteristic() != SrcMgr::C_User;
143   }
144 
145   /// Whether this header map is building a framework or not.
146   bool isIndexHeaderMap() const {
147     return isHeaderMap() && IsIndexHeaderMap;
148   }
149 
150   /// LookupFile - Lookup the specified file in this search path, returning it
151   /// if it exists or returning null if not.
152   ///
153   /// \param Filename The file to look up relative to the search paths.
154   ///
155   /// \param HS The header search instance to search with.
156   ///
157   /// \param IncludeLoc the source location of the #include or #import
158   /// directive.
159   ///
160   /// \param SearchPath If not NULL, will be set to the search path relative
161   /// to which the file was found.
162   ///
163   /// \param RelativePath If not NULL, will be set to the path relative to
164   /// SearchPath at which the file was found. This only differs from the
165   /// Filename for framework includes.
166   ///
167   /// \param RequestingModule The module in which the lookup was performed.
168   ///
169   /// \param SuggestedModule If non-null, and the file found is semantically
170   /// part of a known module, this will be set to the module that should
171   /// be imported instead of preprocessing/parsing the file found.
172   ///
173   /// \param [out] InUserSpecifiedSystemFramework If the file is found,
174   /// set to true if the file is located in a framework that has been
175   /// user-specified to be treated as a system framework.
176   ///
177   /// \param [out] IsFrameworkFound For a framework directory set to true if
178   /// specified '.framework' directory is found.
179   ///
180   /// \param [out] MappedName if this is a headermap which maps the filename to
181   /// a framework include ("Foo.h" -> "Foo/Foo.h"), set the new name to this
182   /// vector and point Filename to it.
183   OptionalFileEntryRef
184   LookupFile(StringRef &Filename, HeaderSearch &HS, SourceLocation IncludeLoc,
185              SmallVectorImpl<char> *SearchPath,
186              SmallVectorImpl<char> *RelativePath, Module *RequestingModule,
187              ModuleMap::KnownHeader *SuggestedModule,
188              bool &InUserSpecifiedSystemFramework, bool &IsFrameworkFound,
189              bool &IsInHeaderMap, SmallVectorImpl<char> &MappedName,
190              bool OpenFile = true) const;
191 
192 private:
193   OptionalFileEntryRef DoFrameworkLookup(
194       StringRef Filename, HeaderSearch &HS, SmallVectorImpl<char> *SearchPath,
195       SmallVectorImpl<char> *RelativePath, Module *RequestingModule,
196       ModuleMap::KnownHeader *SuggestedModule,
197       bool &InUserSpecifiedSystemFramework, bool &IsFrameworkFound) const;
198 };
199 
200 }  // end namespace clang
201 
202 #endif
203