clang-tools  4.0.0
QueryParser.cpp
Go to the documentation of this file.
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 { return Switch.Default(Value); }
80 };
81 
82 // Lexes a word and stores it in Word. Returns a LexOrCompleteWord<T> object
83 // that can be used like a llvm::StringSwitch<T>, but adds cases as possible
84 // completions if the lexed word contains the completion point.
85 template <typename T>
87 QueryParser::lexOrCompleteWord(StringRef &Word) {
88  Word = lexWord();
89  size_t WordCompletionPos = StringRef::npos;
90  if (CompletionPos && CompletionPos <= Word.data() + Word.size()) {
91  if (CompletionPos < Word.data())
92  WordCompletionPos = 0;
93  else
94  WordCompletionPos = CompletionPos - Word.data();
95  }
96  return LexOrCompleteWord<T>(this, Word, WordCompletionPos);
97 }
98 
99 QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
100  StringRef ValStr;
101  unsigned Value = lexOrCompleteWord<unsigned>(ValStr)
102  .Case("false", 0)
103  .Case("true", 1)
104  .Default(~0u);
105  if (Value == ~0u) {
106  return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
107  }
108  return new SetQuery<bool>(Var, Value);
109 }
110 
111 QueryRef QueryParser::parseSetOutputKind() {
112  StringRef ValStr;
113  unsigned OutKind = lexOrCompleteWord<unsigned>(ValStr)
114  .Case("diag", OK_Diag)
115  .Case("print", OK_Print)
116  .Case("dump", OK_Dump)
117  .Default(~0u);
118  if (OutKind == ~0u) {
119  return new InvalidQuery("expected 'diag', 'print' or 'dump', got '" +
120  ValStr + "'");
121  }
122  return new SetQuery<OutputKind>(&QuerySession::OutKind, OutputKind(OutKind));
123 }
124 
125 QueryRef QueryParser::endQuery(QueryRef Q) {
126  const char *Extra = Begin;
127  if (!lexWord().empty())
128  return new InvalidQuery("unexpected extra input: '" +
129  StringRef(Extra, End - Extra) + "'");
130  return Q;
131 }
132 
133 namespace {
134 
135 enum ParsedQueryKind {
136  PQK_Invalid,
137  PQK_NoOp,
138  PQK_Help,
139  PQK_Let,
140  PQK_Match,
141  PQK_Set,
142  PQK_Unlet,
143  PQK_Quit
144 };
145 
146 enum ParsedQueryVariable { PQV_Invalid, PQV_Output, PQV_BindRoot };
147 
148 QueryRef makeInvalidQueryFromDiagnostics(const Diagnostics &Diag) {
149  std::string ErrStr;
150  llvm::raw_string_ostream OS(ErrStr);
151  Diag.printToStreamFull(OS);
152  return new InvalidQuery(OS.str());
153 }
154 
155 } // namespace
156 
157 QueryRef QueryParser::completeMatcherExpression() {
158  std::vector<MatcherCompletion> Comps = Parser::completeExpression(
159  StringRef(Begin, End - Begin), CompletionPos - Begin, nullptr,
160  &QS.NamedValues);
161  for (auto I = Comps.begin(), E = Comps.end(); I != E; ++I) {
162  Completions.push_back(LineEditor::Completion(I->TypedText, I->MatcherDecl));
163  }
164  return QueryRef();
165 }
166 
167 QueryRef QueryParser::doParse() {
168  StringRef CommandStr;
169  ParsedQueryKind QKind = lexOrCompleteWord<ParsedQueryKind>(CommandStr)
170  .Case("", PQK_NoOp)
171  .Case("help", PQK_Help)
172  .Case("m", PQK_Match, /*IsCompletion=*/false)
173  .Case("let", PQK_Let)
174  .Case("match", PQK_Match)
175  .Case("set", PQK_Set)
176  .Case("unlet", PQK_Unlet)
177  .Case("quit", PQK_Quit)
178  .Default(PQK_Invalid);
179 
180  switch (QKind) {
181  case PQK_NoOp:
182  return new NoOpQuery;
183 
184  case PQK_Help:
185  return endQuery(new HelpQuery);
186 
187  case PQK_Quit:
188  return endQuery(new QuitQuery);
189 
190  case PQK_Let: {
191  StringRef Name = lexWord();
192 
193  if (Name.empty())
194  return new InvalidQuery("expected variable name");
195 
196  if (CompletionPos)
197  return completeMatcherExpression();
198 
199  Diagnostics Diag;
200  ast_matchers::dynamic::VariantValue Value;
201  if (!Parser::parseExpression(StringRef(Begin, End - Begin), nullptr,
202  &QS.NamedValues, &Value, &Diag)) {
203  return makeInvalidQueryFromDiagnostics(Diag);
204  }
205 
206  return new LetQuery(Name, Value);
207  }
208 
209  case PQK_Match: {
210  if (CompletionPos)
211  return completeMatcherExpression();
212 
213  Diagnostics Diag;
214  Optional<DynTypedMatcher> Matcher = Parser::parseMatcherExpression(
215  StringRef(Begin, End - Begin), nullptr, &QS.NamedValues, &Diag);
216  if (!Matcher) {
217  return makeInvalidQueryFromDiagnostics(Diag);
218  }
219  return new MatchQuery(*Matcher);
220  }
221 
222  case PQK_Set: {
223  StringRef VarStr;
224  ParsedQueryVariable Var = lexOrCompleteWord<ParsedQueryVariable>(VarStr)
225  .Case("output", PQV_Output)
226  .Case("bind-root", PQV_BindRoot)
227  .Default(PQV_Invalid);
228  if (VarStr.empty())
229  return new InvalidQuery("expected variable name");
230  if (Var == PQV_Invalid)
231  return new InvalidQuery("unknown variable: '" + VarStr + "'");
232 
233  QueryRef Q;
234  switch (Var) {
235  case PQV_Output:
236  Q = parseSetOutputKind();
237  break;
238  case PQV_BindRoot:
239  Q = parseSetBool(&QuerySession::BindRoot);
240  break;
241  case PQV_Invalid:
242  llvm_unreachable("Invalid query kind");
243  }
244 
245  return endQuery(Q);
246  }
247 
248  case PQK_Unlet: {
249  StringRef Name = lexWord();
250 
251  if (Name.empty())
252  return new InvalidQuery("expected variable name");
253 
254  return endQuery(new LetQuery(Name, VariantValue()));
255  }
256 
257  case PQK_Invalid:
258  return new InvalidQuery("unknown command: " + CommandStr);
259  }
260 
261  llvm_unreachable("Invalid query kind");
262 }
263 
264 QueryRef QueryParser::parse(StringRef Line, const QuerySession &QS) {
265  return QueryParser(Line, QS).doParse();
266 }
267 
268 std::vector<LineEditor::Completion>
269 QueryParser::complete(StringRef Line, size_t Pos, const QuerySession &QS) {
270  QueryParser P(Line, QS);
271  P.CompletionPos = Line.data() + Pos;
272 
273  P.doParse();
274  return P.Completions;
275 }
276 
277 } // namespace query
278 } // namespace clang
const std::string Name
Definition: USRFinder.cpp:164
Represents the state for a particular clang-query session.
Definition: QuerySession.h:25
llvm::IntrusiveRefCntPtr< Query > QueryRef
Definition: Query.h:48
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