summaryrefslogtreecommitdiffstats
path: root/lib/Format/UsingDeclarationsSorter.cpp
blob: d6753b545e255753265539a45d680ad90aa8a7ce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
//===--- UsingDeclarationsSorter.cpp ----------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file implements UsingDeclarationsSorter, a TokenAnalyzer that
/// sorts consecutive using declarations.
///
//===----------------------------------------------------------------------===//

#include "UsingDeclarationsSorter.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Regex.h"

#include <algorithm>

#define DEBUG_TYPE "using-declarations-sorter"

namespace clang {
namespace format {

namespace {

struct UsingDeclaration {
  const AnnotatedLine *Line;
  std::string Label;

  UsingDeclaration(const AnnotatedLine *Line, const std::string &Label)
      : Line(Line), Label(Label) {}

  bool operator<(const UsingDeclaration &Other) const {
    return StringRef(Label).compare_lower(Other.Label) < 0;
  }
};

/// Computes the label of a using declaration starting at tthe using token
/// \p UsingTok.
/// If \p UsingTok doesn't begin a using declaration, returns the empty string.
/// Note that this detects specifically using declarations, as in:
/// using A::B::C;
/// and not type aliases, as in:
/// using A = B::C;
/// Type aliases are in general not safe to permute.
std::string computeUsingDeclarationLabel(const FormatToken *UsingTok) {
  assert(UsingTok && UsingTok->is(tok::kw_using) && "Expecting a using token");
  std::string Label;
  const FormatToken *Tok = UsingTok->Next;
  if (Tok && Tok->is(tok::kw_typename)) {
    Label.append("typename ");
    Tok = Tok->Next;
  }
  if (Tok && Tok->is(tok::coloncolon)) {
    Label.append("::");
    Tok = Tok->Next;
  }
  bool HasIdentifier = false;
  while (Tok && Tok->is(tok::identifier)) {
    HasIdentifier = true;
    Label.append(Tok->TokenText.str());
    Tok = Tok->Next;
    if (!Tok || Tok->isNot(tok::coloncolon))
      break;
    Label.append("::");
    Tok = Tok->Next;
  }
  if (HasIdentifier && Tok && Tok->isOneOf(tok::semi, tok::comma))
    return Label;
  return "";
}

void endUsingDeclarationBlock(
    SmallVectorImpl<UsingDeclaration> *UsingDeclarations,
    const SourceManager &SourceMgr, tooling::Replacements *Fixes) {
  bool BlockAffected = false;
  for (const UsingDeclaration& Declaration : *UsingDeclarations) {
    if (Declaration.Line->Affected) {
      BlockAffected = true;
      break;
    }
  }
  if (!BlockAffected) {
    UsingDeclarations->clear();
    return;
  }
  SmallVector<UsingDeclaration, 4> SortedUsingDeclarations(
      UsingDeclarations->begin(), UsingDeclarations->end());
  std::stable_sort(SortedUsingDeclarations.begin(),
                   SortedUsingDeclarations.end());
  for (size_t I = 0, E = UsingDeclarations->size(); I < E; ++I) {
    if ((*UsingDeclarations)[I].Line == SortedUsingDeclarations[I].Line)
      continue;
    auto Begin = (*UsingDeclarations)[I].Line->First->Tok.getLocation();
    auto End = (*UsingDeclarations)[I].Line->Last->Tok.getEndLoc();
    auto SortedBegin =
        SortedUsingDeclarations[I].Line->First->Tok.getLocation();
    auto SortedEnd = SortedUsingDeclarations[I].Line->Last->Tok.getEndLoc();
    StringRef Text(SourceMgr.getCharacterData(SortedBegin),
                   SourceMgr.getCharacterData(SortedEnd) -
                       SourceMgr.getCharacterData(SortedBegin));
    DEBUG({
      StringRef OldText(SourceMgr.getCharacterData(Begin),
                        SourceMgr.getCharacterData(End) -
                            SourceMgr.getCharacterData(Begin));
      llvm::dbgs() << "Replacing '" << OldText << "' with '" << Text << "'\n";
    });
    auto Range = CharSourceRange::getCharRange(Begin, End);
    auto Err = Fixes->add(tooling::Replacement(SourceMgr, Range, Text));
    if (Err) {
      llvm::errs() << "Error while sorting using declarations: "
                   << llvm::toString(std::move(Err)) << "\n";
    }
  }
  UsingDeclarations->clear();
}

} // namespace

UsingDeclarationsSorter::UsingDeclarationsSorter(const Environment &Env,
                                                 const FormatStyle &Style)
    : TokenAnalyzer(Env, Style) {}

std::pair<tooling::Replacements, unsigned> UsingDeclarationsSorter::analyze(
    TokenAnnotator &Annotator, SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
    FormatTokenLexer &Tokens) {
  const SourceManager &SourceMgr = Env.getSourceManager();
  AffectedRangeMgr.computeAffectedLines(AnnotatedLines.begin(),
                                        AnnotatedLines.end());
  tooling::Replacements Fixes;
  SmallVector<UsingDeclaration, 4> UsingDeclarations;
  for (size_t I = 0, E = AnnotatedLines.size(); I != E; ++I) {
    if (AnnotatedLines[I]->InPPDirective ||
        !AnnotatedLines[I]->startsWith(tok::kw_using) ||
        AnnotatedLines[I]->First->Finalized) {
      endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
      continue;
    }
    if (AnnotatedLines[I]->First->NewlinesBefore > 1)
      endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
    std::string Label = computeUsingDeclarationLabel(AnnotatedLines[I]->First);
    if (Label.empty()) {
      endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
      continue;
    }
    UsingDeclarations.push_back(UsingDeclaration(AnnotatedLines[I], Label));
  }
  endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
  return {Fixes, 0};
}

} // namespace format
} // namespace clang