clang-tools  3.8.0
QueryParser.cpp
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1 //===---- QueryParser.cpp - clang-query command parser --------------------===//
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 #include "QueryParser.h"
11 #include "Query.h"
12 #include "QuerySession.h"
13 #include "clang/ASTMatchers/Dynamic/Parser.h"
14 #include "clang/Basic/CharInfo.h"
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/ADT/StringSwitch.h"
17 #include <set>
18 
19 using namespace llvm;
20 using namespace clang::ast_matchers::dynamic;
21 
22 namespace clang {
23 namespace query {
24 
25 // Lex any amount of whitespace followed by a "word" (any sequence of
26 // non-whitespace characters) from the start of region [Begin,End). If no word
27 // is found before End, return StringRef(). Begin is adjusted to exclude the
28 // lexed region.
29 StringRef QueryParser::lexWord() {
30  while (true) {
31  if (Begin == End)
32  return StringRef(Begin, 0);
33 
34  if (!isWhitespace(*Begin))
35  break;
36 
37  ++Begin;
38  }
39 
40  const char *WordBegin = Begin;
41 
42  while (true) {
43  ++Begin;
44 
45  if (Begin == End || isWhitespace(*Begin))
46  return StringRef(WordBegin, Begin - WordBegin);
47  }
48 }
49 
50 // This is the StringSwitch-alike used by lexOrCompleteWord below. See that
51 // function for details.
52 template <typename T> struct QueryParser::LexOrCompleteWord {
53  StringSwitch<T> Switch;
54 
56  StringRef Word;
57  // Set to the completion point offset in Word, or StringRef::npos if
58  // completion point not in Word.
60 
61  LexOrCompleteWord(QueryParser *P, StringRef Word, size_t WCP)
62  : Switch(Word), P(P), Word(Word), WordCompletionPos(WCP) {}
63 
64  template <unsigned N>
65  LexOrCompleteWord &Case(const char (&S)[N], const T &Value,
66  bool IsCompletion = true) {
67  StringRef CaseStr(S, N - 1);
68 
69  if (WordCompletionPos == StringRef::npos)
70  Switch.Case(S, Value);
71  else if (N != 1 && IsCompletion && WordCompletionPos <= CaseStr.size() &&
72  CaseStr.substr(0, WordCompletionPos) ==
73  Word.substr(0, WordCompletionPos))
74  P->Completions.push_back(LineEditor::Completion(
75  (CaseStr.substr(WordCompletionPos) + " ").str(), CaseStr));
76  return *this;
77  }
78 
79  T Default(const T& Value) const {
80  return Switch.Default(Value);
81  }
82 };
83 
84 // Lexes a word and stores it in Word. Returns a LexOrCompleteWord<T> object
85 // that can be used like a llvm::StringSwitch<T>, but adds cases as possible
86 // completions if the lexed word contains the completion point.
87 template <typename T>
89 QueryParser::lexOrCompleteWord(StringRef &Word) {
90  Word = lexWord();
91  size_t WordCompletionPos = StringRef::npos;
92  if (CompletionPos && CompletionPos <= Word.data() + Word.size()) {
93  if (CompletionPos < Word.data())
94  WordCompletionPos = 0;
95  else
96  WordCompletionPos = CompletionPos - Word.data();
97  }
98  return LexOrCompleteWord<T>(this, Word, WordCompletionPos);
99 }
100 
101 QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
102  StringRef ValStr;
103  unsigned Value = lexOrCompleteWord<unsigned>(ValStr)
104  .Case("false", 0)
105  .Case("true", 1)
106  .Default(~0u);
107  if (Value == ~0u) {
108  return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
109  }
110  return new SetQuery<bool>(Var, Value);
111 }
112 
113 QueryRef QueryParser::parseSetOutputKind() {
114  StringRef ValStr;
115  unsigned OutKind = lexOrCompleteWord<unsigned>(ValStr)
116  .Case("diag", OK_Diag)
117  .Case("print", OK_Print)
118  .Case("dump", OK_Dump)
119  .Default(~0u);
120  if (OutKind == ~0u) {
121  return new InvalidQuery("expected 'diag', 'print' or 'dump', got '" +
122  ValStr + "'");
123  }
124  return new SetQuery<OutputKind>(&QuerySession::OutKind, OutputKind(OutKind));
125 }
126 
127 QueryRef QueryParser::endQuery(QueryRef Q) {
128  const char *Extra = Begin;
129  if (!lexWord().empty())
130  return new InvalidQuery("unexpected extra input: '" +
131  StringRef(Extra, End - Extra) + "'");
132  return Q;
133 }
134 
135 namespace {
136 
137 enum ParsedQueryKind {
138  PQK_Invalid,
139  PQK_NoOp,
140  PQK_Help,
141  PQK_Let,
142  PQK_Match,
143  PQK_Set,
144  PQK_Unlet,
145  PQK_Quit
146 };
147 
148 enum ParsedQueryVariable {
149  PQV_Invalid,
150  PQV_Output,
151  PQV_BindRoot
152 };
153 
154 QueryRef makeInvalidQueryFromDiagnostics(const Diagnostics &Diag) {
155  std::string ErrStr;
156  llvm::raw_string_ostream OS(ErrStr);
157  Diag.printToStreamFull(OS);
158  return new InvalidQuery(OS.str());
159 }
160 
161 } // namespace
162 
163 QueryRef QueryParser::completeMatcherExpression() {
164  std::vector<MatcherCompletion> Comps = Parser::completeExpression(
165  StringRef(Begin, End - Begin), CompletionPos - Begin, nullptr,
166  &QS.NamedValues);
167  for (std::vector<MatcherCompletion>::iterator I = Comps.begin(),
168  E = Comps.end();
169  I != E; ++I) {
170  Completions.push_back(LineEditor::Completion(I->TypedText, I->MatcherDecl));
171  }
172  return QueryRef();
173 }
174 
175 QueryRef QueryParser::doParse() {
176  StringRef CommandStr;
177  ParsedQueryKind QKind = lexOrCompleteWord<ParsedQueryKind>(CommandStr)
178  .Case("", PQK_NoOp)
179  .Case("help", PQK_Help)
180  .Case("m", PQK_Match, /*IsCompletion=*/false)
181  .Case("let", PQK_Let)
182  .Case("match", PQK_Match)
183  .Case("set", PQK_Set)
184  .Case("unlet", PQK_Unlet)
185  .Case("quit", PQK_Quit)
186  .Default(PQK_Invalid);
187 
188  switch (QKind) {
189  case PQK_NoOp:
190  return new NoOpQuery;
191 
192  case PQK_Help:
193  return endQuery(new HelpQuery);
194 
195  case PQK_Quit:
196  return endQuery(new QuitQuery);
197 
198  case PQK_Let: {
199  StringRef Name = lexWord();
200 
201  if (Name.empty())
202  return new InvalidQuery("expected variable name");
203 
204  if (CompletionPos)
205  return completeMatcherExpression();
206 
207  Diagnostics Diag;
208  ast_matchers::dynamic::VariantValue Value;
209  if (!Parser::parseExpression(StringRef(Begin, End - Begin), nullptr,
210  &QS.NamedValues, &Value, &Diag)) {
211  return makeInvalidQueryFromDiagnostics(Diag);
212  }
213 
214  return new LetQuery(Name, Value);
215  }
216 
217  case PQK_Match: {
218  if (CompletionPos)
219  return completeMatcherExpression();
220 
221  Diagnostics Diag;
222  Optional<DynTypedMatcher> Matcher = Parser::parseMatcherExpression(
223  StringRef(Begin, End - Begin), nullptr, &QS.NamedValues, &Diag);
224  if (!Matcher) {
225  return makeInvalidQueryFromDiagnostics(Diag);
226  }
227  return new MatchQuery(*Matcher);
228  }
229 
230  case PQK_Set: {
231  StringRef VarStr;
232  ParsedQueryVariable Var = lexOrCompleteWord<ParsedQueryVariable>(VarStr)
233  .Case("output", PQV_Output)
234  .Case("bind-root", PQV_BindRoot)
235  .Default(PQV_Invalid);
236  if (VarStr.empty())
237  return new InvalidQuery("expected variable name");
238  if (Var == PQV_Invalid)
239  return new InvalidQuery("unknown variable: '" + VarStr + "'");
240 
241  QueryRef Q;
242  switch (Var) {
243  case PQV_Output:
244  Q = parseSetOutputKind();
245  break;
246  case PQV_BindRoot:
247  Q = parseSetBool(&QuerySession::BindRoot);
248  break;
249  case PQV_Invalid:
250  llvm_unreachable("Invalid query kind");
251  }
252 
253  return endQuery(Q);
254  }
255 
256  case PQK_Unlet: {
257  StringRef Name = lexWord();
258 
259  if (Name.empty())
260  return new InvalidQuery("expected variable name");
261 
262  return endQuery(new LetQuery(Name, VariantValue()));
263  }
264 
265  case PQK_Invalid:
266  return new InvalidQuery("unknown command: " + CommandStr);
267  }
268 
269  llvm_unreachable("Invalid query kind");
270 }
271 
272 QueryRef QueryParser::parse(StringRef Line, const QuerySession &QS) {
273  return QueryParser(Line, QS).doParse();
274 }
275 
276 std::vector<LineEditor::Completion>
277 QueryParser::complete(StringRef Line, size_t Pos, const QuerySession &QS) {
278  QueryParser P(Line, QS);
279  P.CompletionPos = Line.data() + Pos;
280 
281  P.doParse();
282  return P.Completions;
283 }
284 
285 } // namespace query
286 } // namespace clang
StringHandle Name
Represents the state for a particular clang-query session.
Definition: QuerySession.h:25
llvm::IntrusiveRefCntPtr< Query > QueryRef
Definition: Query.h:52
LexOrCompleteWord & Case(const char(&S)[N], const T &Value, bool IsCompletion=true)
Definition: QueryParser.cpp:65
LexOrCompleteWord(QueryParser *P, StringRef Word, size_t WCP)
Definition: QueryParser.cpp:61