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   if (*Begin == '#') {
41     End = Begin;
42     return StringRef();
43   }
44 
45   const char *WordBegin = Begin;
46 
47   while (true) {
48     ++Begin;
49 
50     if (Begin == End || isWhitespace(*Begin))
51       return StringRef(WordBegin, Begin - WordBegin);
52   }
53 }
54 
55 // This is the StringSwitch-alike used by lexOrCompleteWord below. See that
56 // function for details.
57 template <typename T> struct QueryParser::LexOrCompleteWord {
58   StringRef Word;
59   StringSwitch<T> Switch;
60 
61   QueryParser *P;
62   // Set to the completion point offset in Word, or StringRef::npos if
63   // completion point not in Word.
64   size_t WordCompletionPos;
65 
66   // Lexes a word and stores it in Word. Returns a LexOrCompleteWord<T> object
67   // that can be used like a llvm::StringSwitch<T>, but adds cases as possible
68   // completions if the lexed word contains the completion point.
69   LexOrCompleteWord(QueryParser *P, StringRef &OutWord)
70       : Word(P->lexWord()), Switch(Word), P(P),
71         WordCompletionPos(StringRef::npos) {
72     OutWord = Word;
73     if (P->CompletionPos && P->CompletionPos <= Word.data() + Word.size()) {
74       if (P->CompletionPos < Word.data())
75         WordCompletionPos = 0;
76       else
77         WordCompletionPos = P->CompletionPos - Word.data();
78     }
79   }
80 
81   LexOrCompleteWord &Case(llvm::StringLiteral CaseStr, const T &Value,
82                           bool IsCompletion = true) {
83 
84     if (WordCompletionPos == StringRef::npos)
85       Switch.Case(CaseStr, Value);
86     else if (CaseStr.size() != 0 && IsCompletion && WordCompletionPos <= CaseStr.size() &&
87              CaseStr.substr(0, WordCompletionPos) ==
88                  Word.substr(0, WordCompletionPos))
89       P->Completions.push_back(LineEditor::Completion(
90           (CaseStr.substr(WordCompletionPos) + " ").str(), CaseStr));
91     return *this;
92   }
93 
94   T Default(T Value) { return Switch.Default(Value); }
95 };
96 
97 QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
98   StringRef ValStr;
99   unsigned Value = LexOrCompleteWord<unsigned>(this, ValStr)
100                        .Case("false", 0)
101                        .Case("true", 1)
102                        .Default(~0u);
103   if (Value == ~0u) {
104     return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
105   }
106   return new SetQuery<bool>(Var, Value);
107 }
108 
109 template <typename QueryType> QueryRef QueryParser::parseSetOutputKind() {
110   StringRef ValStr;
111   unsigned OutKind = LexOrCompleteWord<unsigned>(this, ValStr)
112                          .Case("diag", OK_Diag)
113                          .Case("print", OK_Print)
114                          .Case("detailed-ast", OK_DetailedAST)
115                          .Case("dump", OK_DetailedAST)
116                          .Default(~0u);
117   if (OutKind == ~0u) {
118     return new InvalidQuery(
119         "expected 'diag', 'print', 'detailed-ast' or 'dump', got '" + ValStr +
120         "'");
121   }
122 
123   switch (OutKind) {
124   case OK_DetailedAST:
125     return new QueryType(&QuerySession::DetailedASTOutput);
126   case OK_Diag:
127     return new QueryType(&QuerySession::DiagOutput);
128   case OK_Print:
129     return new QueryType(&QuerySession::PrintOutput);
130   }
131 
132   llvm_unreachable("Invalid output kind");
133 }
134 
135 QueryRef QueryParser::endQuery(QueryRef Q) {
136   const char *Extra = Begin;
137   if (!lexWord().empty())
138     return new InvalidQuery("unexpected extra input: '" +
139                             StringRef(Extra, End - Extra) + "'");
140   return Q;
141 }
142 
143 namespace {
144 
145 enum ParsedQueryKind {
146   PQK_Invalid,
147   PQK_Comment,
148   PQK_NoOp,
149   PQK_Help,
150   PQK_Let,
151   PQK_Match,
152   PQK_Set,
153   PQK_Unlet,
154   PQK_Quit,
155   PQK_Enable,
156   PQK_Disable
157 };
158 
159 enum ParsedQueryVariable {
160   PQV_Invalid,
161   PQV_Output,
162   PQV_BindRoot,
163   PQV_PrintMatcher
164 };
165 
166 QueryRef makeInvalidQueryFromDiagnostics(const Diagnostics &Diag) {
167   std::string ErrStr;
168   llvm::raw_string_ostream OS(ErrStr);
169   Diag.printToStreamFull(OS);
170   return new InvalidQuery(OS.str());
171 }
172 
173 } // namespace
174 
175 QueryRef QueryParser::completeMatcherExpression() {
176   std::vector<MatcherCompletion> Comps = Parser::completeExpression(
177       StringRef(Begin, End - Begin), CompletionPos - Begin, nullptr,
178       &QS.NamedValues);
179   for (auto I = Comps.begin(), E = Comps.end(); I != E; ++I) {
180     Completions.push_back(LineEditor::Completion(I->TypedText, I->MatcherDecl));
181   }
182   return QueryRef();
183 }
184 
185 QueryRef QueryParser::doParse() {
186   StringRef CommandStr;
187   ParsedQueryKind QKind = LexOrCompleteWord<ParsedQueryKind>(this, CommandStr)
188                               .Case("", PQK_NoOp)
189                               .Case("#", PQK_Comment, /*IsCompletion=*/false)
190                               .Case("help", PQK_Help)
191                               .Case("l", PQK_Let, /*IsCompletion=*/false)
192                               .Case("let", PQK_Let)
193                               .Case("m", PQK_Match, /*IsCompletion=*/false)
194                               .Case("match", PQK_Match)
195                               .Case("q", PQK_Quit,  /*IsCompletion=*/false)
196                               .Case("quit", PQK_Quit)
197                               .Case("set", PQK_Set)
198                               .Case("enable", PQK_Enable)
199                               .Case("disable", PQK_Disable)
200                               .Case("unlet", PQK_Unlet)
201                               .Default(PQK_Invalid);
202 
203   switch (QKind) {
204   case PQK_Comment:
205   case PQK_NoOp:
206     return new NoOpQuery;
207 
208   case PQK_Help:
209     return endQuery(new HelpQuery);
210 
211   case PQK_Quit:
212     return endQuery(new QuitQuery);
213 
214   case PQK_Let: {
215     StringRef Name = lexWord();
216 
217     if (Name.empty())
218       return new InvalidQuery("expected variable name");
219 
220     if (CompletionPos)
221       return completeMatcherExpression();
222 
223     Diagnostics Diag;
224     ast_matchers::dynamic::VariantValue Value;
225     if (!Parser::parseExpression(StringRef(Begin, End - Begin), nullptr,
226                                  &QS.NamedValues, &Value, &Diag)) {
227       return makeInvalidQueryFromDiagnostics(Diag);
228     }
229 
230     return new LetQuery(Name, Value);
231   }
232 
233   case PQK_Match: {
234     if (CompletionPos)
235       return completeMatcherExpression();
236 
237     Diagnostics Diag;
238     auto MatcherSource = StringRef(Begin, End - Begin).trim();
239     Optional<DynTypedMatcher> Matcher = Parser::parseMatcherExpression(
240         MatcherSource, nullptr, &QS.NamedValues, &Diag);
241     if (!Matcher) {
242       return makeInvalidQueryFromDiagnostics(Diag);
243     }
244     return new MatchQuery(MatcherSource, *Matcher);
245   }
246 
247   case PQK_Set: {
248     StringRef VarStr;
249     ParsedQueryVariable Var =
250         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
251             .Case("output", PQV_Output)
252             .Case("bind-root", PQV_BindRoot)
253             .Case("print-matcher", PQV_PrintMatcher)
254             .Default(PQV_Invalid);
255     if (VarStr.empty())
256       return new InvalidQuery("expected variable name");
257     if (Var == PQV_Invalid)
258       return new InvalidQuery("unknown variable: '" + VarStr + "'");
259 
260     QueryRef Q;
261     switch (Var) {
262     case PQV_Output:
263       Q = parseSetOutputKind<SetExclusiveOutputQuery>();
264       break;
265     case PQV_BindRoot:
266       Q = parseSetBool(&QuerySession::BindRoot);
267       break;
268     case PQV_PrintMatcher:
269       Q = parseSetBool(&QuerySession::PrintMatcher);
270       break;
271     case PQV_Invalid:
272       llvm_unreachable("Invalid query kind");
273     }
274 
275     return endQuery(Q);
276   }
277   case PQK_Enable:
278   case PQK_Disable: {
279     StringRef VarStr;
280     ParsedQueryVariable Var =
281         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
282             .Case("output", PQV_Output)
283             .Default(PQV_Invalid);
284     if (VarStr.empty())
285       return new InvalidQuery("expected variable name");
286     if (Var == PQV_Invalid)
287       return new InvalidQuery("unknown variable: '" + VarStr + "'");
288 
289     QueryRef Q;
290 
291     if (QKind == PQK_Enable)
292       Q = parseSetOutputKind<EnableOutputQuery>();
293     else if (QKind == PQK_Disable)
294       Q = parseSetOutputKind<DisableOutputQuery>();
295     else
296       llvm_unreachable("Invalid query kind");
297     return endQuery(Q);
298   }
299 
300   case PQK_Unlet: {
301     StringRef Name = lexWord();
302 
303     if (Name.empty())
304       return new InvalidQuery("expected variable name");
305 
306     return endQuery(new LetQuery(Name, VariantValue()));
307   }
308 
309   case PQK_Invalid:
310     return new InvalidQuery("unknown command: " + CommandStr);
311   }
312 
313   llvm_unreachable("Invalid query kind");
314 }
315 
316 QueryRef QueryParser::parse(StringRef Line, const QuerySession &QS) {
317   return QueryParser(Line, QS).doParse();
318 }
319 
320 std::vector<LineEditor::Completion>
321 QueryParser::complete(StringRef Line, size_t Pos, const QuerySession &QS) {
322   QueryParser P(Line, QS);
323   P.CompletionPos = Line.data() + Pos;
324 
325   P.doParse();
326   return P.Completions;
327 }
328 
329 } // namespace query
330 } // namespace clang
331