clang-tools 8.0.0

CanonicalIncludes.h
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1 //===-- CanonicalIncludes.h - remap #include header -------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // At indexing time, we decide which file to #included for a symbol.
11 // Usually this is the file with the canonical decl, but there are exceptions:
12 // - private headers may have pragmas pointing to the matching public header.
13 // (These are "IWYU" pragmas, named after the include-what-you-use tool).
14 // - the standard library is implemented in many files, without any pragmas.
15 // We have a lookup table for common standard library implementations.
16 // libstdc++ puts char_traits in bits/char_traits.h, but we #include <string>.
17 //
18 //===----------------------------------------------------------------------===//
19
20 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_CANONICALINCLUDES_H
21 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_CANONICALINCLUDES_H
22
23 #include "clang/Lex/Preprocessor.h"
24 #include "llvm/ADT/StringMap.h"
25 #include "llvm/Support/Regex.h"
26 #include <mutex>
27 #include <string>
28 #include <vector>
29
30 namespace clang {
31 namespace clangd {
32
33 /// Maps a definition location onto an #include file, based on a set of filename
34 /// rules.
35 /// Only const methods (i.e. mapHeader) in this class are thread safe.
36 class CanonicalIncludes {
37 public:
38 CanonicalIncludes() = default;
39
40 /// Adds a string-to-string mapping from \p Path to \p CanonicalPath.
41 void addMapping(llvm::StringRef Path, llvm::StringRef CanonicalPath);
42
43 /// Maps files with last path components matching \p Suffix to \p
44 /// CanonicalPath.
45 void addPathSuffixMapping(llvm::StringRef Suffix,
46 llvm::StringRef CanonicalPath);
47
48 /// Sets the canonical include for any symbol with \p QualifiedName.
49 /// Symbol mappings take precedence over header mappings.
50 void addSymbolMapping(llvm::StringRef QualifiedName,
51 llvm::StringRef CanonicalPath);
52
53 /// Returns the canonical include for symbol with \p QualifiedName.
54 /// \p Headers is the include stack: Headers.front() is the file declaring the
55 /// symbol, and Headers.back() is the main file.
56 llvm::StringRef mapHeader(llvm::ArrayRef<std::string> Headers,
57 llvm::StringRef QualifiedName) const;
58
59 private:
60 /// A map from full include path to a canonical path.
61 llvm::StringMap<std::string> FullPathMapping;
62 /// A map from a suffix (one or components of a path) to a canonical path.
63 llvm::StringMap<std::string> SuffixHeaderMapping;
64 /// Maximum number of path components stored in a key of SuffixHeaderMapping.
65 /// Used to reduce the number of lookups into SuffixHeaderMapping.
66 int MaxSuffixComponents = 0;
67 /// A map from fully qualified symbol names to header names.
68 llvm::StringMap<std::string> SymbolMapping;
69 };
70
71 /// Returns a CommentHandler that parses pragma comment on include files to
72 /// determine when we should include a different header from the header that
73 /// directly defines a symbol. Mappinps are registered with \p Includes.
74 ///
75 /// Currently it only supports IWYU private pragma:
76 /// https://github.com/include-what-you-use/include-what-you-use/blob/master/docs/IWYUPragmas.md#iwyu-pragma-private
77 std::unique_ptr<CommentHandler>
78 collectIWYUHeaderMaps(CanonicalIncludes *Includes);
79
80 /// Adds mapping for system headers and some special symbols (e.g. STL symbols
81 /// in <iosfwd> need to be mapped individually). Approximately, the following
82 /// system headers are handled:
83 /// - C++ standard library e.g. bits/basic_string.h$ -> <string>
84 /// - Posix library e.g. bits/pthreadtypes.h$ -> <pthread.h>
85 /// - Compiler extensions, e.g. include/avx512bwintrin.h$ -> <immintrin.h>
86 /// The mapping is hardcoded and hand-maintained, so it might not cover all
87 /// headers.
88 void addSystemHeadersMapping(CanonicalIncludes *Includes);
89
90 } // namespace clangd
91 } // namespace clang
92
93 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_HEADERMAPCOLLECTOR_H
clang::clangd::collectIWYUHeaderMaps
std::unique_ptr< CommentHandler > collectIWYUHeaderMaps(CanonicalIncludes *Includes)
Returns a CommentHandler that parses pragma comment on include files to determine when we should incl...
Definition: CanonicalIncludes.cpp:84
clang::clangd::CanonicalIncludes::addSymbolMapping
void addSymbolMapping(llvm::StringRef QualifiedName, llvm::StringRef CanonicalPath)
Sets the canonical include for any symbol with QualifiedName.
Definition: CanonicalIncludes.cpp:35
clang::clangd::CanonicalIncludes
Maps a definition location onto an #include file, based on a set of filename rules.
Definition: CanonicalIncludes.h:36
clang::clangd::CanonicalIncludes::addMapping
void addMapping(llvm::StringRef Path, llvm::StringRef CanonicalPath)
Adds a string-to-string mapping from Path to CanonicalPath.
Definition: CanonicalIncludes.cpp:30
clang::clangd::Path
std::string Path
A typedef to represent a file path.
Definition: Path.h:21
clang::clangd::CanonicalIncludes::CanonicalIncludes
CanonicalIncludes()=default
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ChangeNamespace.cpp:18
clang::clangd::CanonicalIncludes::mapHeader
llvm::StringRef mapHeader(llvm::ArrayRef< std::string > Headers, llvm::StringRef QualifiedName) const
Returns the canonical include for symbol with QualifiedName.
Definition: CanonicalIncludes.cpp:41
clang::clangd::addSystemHeadersMapping
void addSystemHeadersMapping(CanonicalIncludes *Includes)
Adds mapping for system headers and some special symbols (e.g.
Definition: CanonicalIncludes.cpp:109
clang::clangd::CanonicalIncludes::addPathSuffixMapping
void addPathSuffixMapping(llvm::StringRef Suffix, llvm::StringRef CanonicalPath)
Maps files with last path components matching Suffix to CanonicalPath.
Definition: CanonicalIncludes.cpp:22