1 //===--- TokenAnalyzer.cpp - Analyze Token Streams --------------*- 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 /// \file
11 /// \brief This file implements an abstract TokenAnalyzer and associated helper
12 /// classes. TokenAnalyzer can be extended to generate replacements based on
13 /// an annotated and pre-processed token stream.
14 ///
15 //===----------------------------------------------------------------------===//
16 
17 #include "TokenAnalyzer.h"
18 #include "AffectedRangeManager.h"
19 #include "Encoding.h"
20 #include "FormatToken.h"
21 #include "FormatTokenLexer.h"
22 #include "TokenAnnotator.h"
23 #include "UnwrappedLineParser.h"
24 #include "clang/Basic/Diagnostic.h"
25 #include "clang/Basic/DiagnosticOptions.h"
26 #include "clang/Basic/FileManager.h"
27 #include "clang/Basic/SourceManager.h"
28 #include "clang/Format/Format.h"
29 #include "llvm/ADT/STLExtras.h"
30 #include "llvm/Support/Debug.h"
31 
32 #define DEBUG_TYPE "format-formatter"
33 
34 namespace clang {
35 namespace format {
36 
37 // This sets up an virtual file system with file \p FileName containing \p
38 // Code.
39 std::unique_ptr<Environment>
40 Environment::CreateVirtualEnvironment(StringRef Code, StringRef FileName,
41                                       ArrayRef<tooling::Range> Ranges,
42                                       unsigned FirstStartColumn,
43                                       unsigned NextStartColumn,
44                                       unsigned LastStartColumn) {
45   // This is referenced by `FileMgr` and will be released by `FileMgr` when it
46   // is deleted.
47   IntrusiveRefCntPtr<vfs::InMemoryFileSystem> InMemoryFileSystem(
48       new vfs::InMemoryFileSystem);
49   // This is passed to `SM` as reference, so the pointer has to be referenced
50   // in `Environment` so that `FileMgr` can out-live this function scope.
51   std::unique_ptr<FileManager> FileMgr(
52       new FileManager(FileSystemOptions(), InMemoryFileSystem));
53   // This is passed to `SM` as reference, so the pointer has to be referenced
54   // by `Environment` due to the same reason above.
55   std::unique_ptr<DiagnosticsEngine> Diagnostics(new DiagnosticsEngine(
56       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
57       new DiagnosticOptions));
58   // This will be stored as reference, so the pointer has to be stored in
59   // due to the same reason above.
60   std::unique_ptr<SourceManager> VirtualSM(
61       new SourceManager(*Diagnostics, *FileMgr));
62   InMemoryFileSystem->addFile(
63       FileName, 0,
64       llvm::MemoryBuffer::getMemBuffer(Code, FileName,
65                                        /*RequiresNullTerminator=*/false));
66   FileID ID = VirtualSM->createFileID(FileMgr->getFile(FileName),
67                                       SourceLocation(), clang::SrcMgr::C_User);
68   assert(ID.isValid());
69   SourceLocation StartOfFile = VirtualSM->getLocForStartOfFile(ID);
70   std::vector<CharSourceRange> CharRanges;
71   for (const tooling::Range &Range : Ranges) {
72     SourceLocation Start = StartOfFile.getLocWithOffset(Range.getOffset());
73     SourceLocation End = Start.getLocWithOffset(Range.getLength());
74     CharRanges.push_back(CharSourceRange::getCharRange(Start, End));
75   }
76   return llvm::make_unique<Environment>(
77       ID, std::move(FileMgr), std::move(VirtualSM), std::move(Diagnostics),
78       CharRanges, FirstStartColumn, NextStartColumn, LastStartColumn);
79 }
80 
81 TokenAnalyzer::TokenAnalyzer(const Environment &Env, const FormatStyle &Style)
82     : Style(Style), Env(Env),
83       AffectedRangeMgr(Env.getSourceManager(), Env.getCharRanges()),
84       UnwrappedLines(1),
85       Encoding(encoding::detectEncoding(
86           Env.getSourceManager().getBufferData(Env.getFileID()))) {
87   DEBUG(
88       llvm::dbgs() << "File encoding: "
89                    << (Encoding == encoding::Encoding_UTF8 ? "UTF8" : "unknown")
90                    << "\n");
91   DEBUG(llvm::dbgs() << "Language: " << getLanguageName(Style.Language)
92                      << "\n");
93 }
94 
95 std::pair<tooling::Replacements, unsigned> TokenAnalyzer::process() {
96   tooling::Replacements Result;
97   FormatTokenLexer Tokens(Env.getSourceManager(), Env.getFileID(),
98                           Env.getFirstStartColumn(), Style, Encoding);
99 
100   UnwrappedLineParser Parser(Style, Tokens.getKeywords(),
101                              Env.getFirstStartColumn(), Tokens.lex(), *this);
102   Parser.parse();
103   assert(UnwrappedLines.rbegin()->empty());
104   unsigned Penalty = 0;
105   for (unsigned Run = 0, RunE = UnwrappedLines.size(); Run + 1 != RunE; ++Run) {
106     DEBUG(llvm::dbgs() << "Run " << Run << "...\n");
107     SmallVector<AnnotatedLine *, 16> AnnotatedLines;
108 
109     TokenAnnotator Annotator(Style, Tokens.getKeywords());
110     for (unsigned i = 0, e = UnwrappedLines[Run].size(); i != e; ++i) {
111       AnnotatedLines.push_back(new AnnotatedLine(UnwrappedLines[Run][i]));
112       Annotator.annotate(*AnnotatedLines.back());
113     }
114 
115     std::pair<tooling::Replacements, unsigned> RunResult =
116         analyze(Annotator, AnnotatedLines, Tokens);
117 
118     DEBUG({
119       llvm::dbgs() << "Replacements for run " << Run << ":\n";
120       for (tooling::Replacements::const_iterator I = RunResult.first.begin(),
121                                                  E = RunResult.first.end();
122            I != E; ++I) {
123         llvm::dbgs() << I->toString() << "\n";
124       }
125     });
126     for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
127       delete AnnotatedLines[i];
128     }
129 
130     Penalty += RunResult.second;
131     for (const auto &R : RunResult.first) {
132       auto Err = Result.add(R);
133       // FIXME: better error handling here. For now, simply return an empty
134       // Replacements to indicate failure.
135       if (Err) {
136         llvm::errs() << llvm::toString(std::move(Err)) << "\n";
137         return {tooling::Replacements(), 0};
138       }
139     }
140   }
141   return {Result, Penalty};
142 }
143 
144 void TokenAnalyzer::consumeUnwrappedLine(const UnwrappedLine &TheLine) {
145   assert(!UnwrappedLines.empty());
146   UnwrappedLines.back().push_back(TheLine);
147 }
148 
149 void TokenAnalyzer::finishRun() {
150   UnwrappedLines.push_back(SmallVector<UnwrappedLine, 16>());
151 }
152 
153 } // end namespace format
154 } // end namespace clang
155