1//===--- CrossTranslationUnit.h - -------------------------------*- 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// This file provides an interface to load binary AST dumps on demand. This
11// feature can be utilized for tools that require cross translation unit
12// support.
13//
14//===----------------------------------------------------------------------===//
15#ifndef LLVM_CLANG_CROSSTU_CROSSTRANSLATIONUNIT_H
16#define LLVM_CLANG_CROSSTU_CROSSTRANSLATIONUNIT_H
17
18#include "clang/Basic/LLVM.h"
19#include "llvm/ADT/DenseMap.h"
20#include "llvm/ADT/SmallPtrSet.h"
21#include "llvm/ADT/StringMap.h"
22#include "llvm/Support/Error.h"
23
24namespace clang {
25class CompilerInstance;
26class ASTContext;
27class ASTImporter;
28class ASTUnit;
29class DeclContext;
30class FunctionDecl;
31class NamedDecl;
32class TranslationUnitDecl;
33
34namespace cross_tu {
35
36enum class index_error_code {
37 unspecified = 1,
38 missing_index_file,
39 invalid_index_format,
40 multiple_definitions,
41 missing_definition,
42 failed_import,
43 failed_to_get_external_ast,
44 failed_to_generate_usr
45};
46
47class IndexError : public llvm::ErrorInfo<IndexError> {
48public:
49 static char ID;
50 IndexError(index_error_code C) : Code(C), LineNo(0) {}
51 IndexError(index_error_code C, std::string FileName, int LineNo = 0)
52 : Code(C), FileName(std::move(FileName)), LineNo(LineNo) {}
53 void log(raw_ostream &OS) const override;
54 std::error_code convertToErrorCode() const override;
55 index_error_code getCode() const { return Code; }
56 int getLineNum() const { return LineNo; }
57 std::string getFileName() const { return FileName; }
58
59private:
60 index_error_code Code;
61 std::string FileName;
62 int LineNo;
63};
64
65/// This function parses an index file that determines which
66/// translation unit contains which definition.
67///
68/// The index file format is the following:
69/// each line consists of an USR and a filepath separated by a space.
70///
71/// \return Returns a map where the USR is the key and the filepath is the value
72/// or an error.
73llvm::Expected<llvm::StringMap<std::string>>
74parseCrossTUIndex(StringRef IndexPath, StringRef CrossTUDir);
75
76std::string createCrossTUIndexString(const llvm::StringMap<std::string> &Index);
77
78/// This class is used for tools that requires cross translation
79/// unit capability.
80///
81/// This class can load function definitions from external AST files.
82/// The loaded definition will be merged back to the original AST using the
83/// AST Importer.
84/// In order to use this class, an index file is required that describes
85/// the locations of the AST files for each function definition.
86///
87/// Note that this class also implements caching.
88class CrossTranslationUnitContext {
89public:
90 CrossTranslationUnitContext(CompilerInstance &CI);
91 ~CrossTranslationUnitContext();
92
93 /// This function loads a function definition from an external AST
94 /// file and merge it into the original AST.
95 ///
96 /// This method should only be used on functions that have no definitions in
97 /// the current translation unit. A function definition with the same
98 /// declaration will be looked up in the index file which should be in the
99 /// \p CrossTUDir directory, called \p IndexName. In case the declaration is
100 /// found in the index the corresponding AST file will be loaded and the
101 /// definition of the function will be merged into the original AST using
102 /// the AST Importer.
103 ///
104 /// \return The declaration with the definition will be returned.
105 /// If no suitable definition is found in the index file or multiple
106 /// definitions found error will be returned.
107 ///
108 /// Note that the AST files should also be in the \p CrossTUDir.
109 llvm::Expected<const FunctionDecl *>
110 getCrossTUDefinition(const FunctionDecl *FD, StringRef CrossTUDir,
111 StringRef IndexName);
112
113 /// This function loads a function definition from an external AST
114 /// file.
115 ///
116 /// A function definition with the same declaration will be looked up in the
117 /// index file which should be in the \p CrossTUDir directory, called
118 /// \p IndexName. In case the declaration is found in the index the
119 /// corresponding AST file will be loaded.
120 ///
121 /// \return Returns an ASTUnit that contains the definition of the looked up
122 /// function.
123 ///
124 /// Note that the AST files should also be in the \p CrossTUDir.
125 llvm::Expected<ASTUnit *> loadExternalAST(StringRef LookupName,
126 StringRef CrossTUDir,
127 StringRef IndexName);
128
129 /// This function merges a definition from a separate AST Unit into
130 /// the current one which was created by the compiler instance that
131 /// was passed to the constructor.
132 ///
133 /// \return Returns the resulting definition or an error.
134 llvm::Expected<const FunctionDecl *> importDefinition(const FunctionDecl *FD);
135
136 /// Get a name to identify a function.
137 static std::string getLookupName(const NamedDecl *ND);
138
139 /// Emit diagnostics for the user for potential configuration errors.
140 void emitCrossTUDiagnostics(const IndexError &IE);
141
142private:
143 ASTImporter &getOrCreateASTImporter(ASTContext &From);
144 const FunctionDecl *findFunctionInDeclContext(const DeclContext *DC,
145 StringRef LookupFnName);
146
147 llvm::StringMap<std::unique_ptr<clang::ASTUnit>> FileASTUnitMap;
148 llvm::StringMap<clang::ASTUnit *> FunctionASTUnitMap;
149 llvm::StringMap<std::string> FunctionFileMap;
150 llvm::DenseMap<TranslationUnitDecl *, std::unique_ptr<ASTImporter>>
151 ASTUnitImporterMap;
152 CompilerInstance &CI;
153 ASTContext &Context;
154};
155
156} // namespace cross_tu
157} // namespace clang
158
159#endif // LLVM_CLANG_CROSSTU_CROSSTRANSLATIONUNIT_H
160