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   Line = Line.ltrim();
31 
32   if (Line.empty())
33     // Even though the Line is empty, it contains a pointer and
34     // a (zero) length. The pointer is used in the LexOrCompleteWord
35     // code completion.
36     return Line;
37 
38   if (Line.front() == '#') {
39     Line = {};
40     return StringRef();
41   }
42 
43   StringRef Word = Line.take_until(isWhitespace);
44   Line = Line.drop_front(Word.size());
45   return Word;
46 }
47 
48 // This is the StringSwitch-alike used by lexOrCompleteWord below. See that
49 // function for details.
50 template <typename T> struct QueryParser::LexOrCompleteWord {
51   StringRef Word;
52   StringSwitch<T> Switch;
53 
54   QueryParser *P;
55   // Set to the completion point offset in Word, or StringRef::npos if
56   // completion point not in Word.
57   size_t WordCompletionPos;
58 
59   // Lexes a word and stores it in Word. Returns a LexOrCompleteWord<T> object
60   // that can be used like a llvm::StringSwitch<T>, but adds cases as possible
61   // completions if the lexed word contains the completion point.
62   LexOrCompleteWord(QueryParser *P, StringRef &OutWord)
63       : Word(P->lexWord()), Switch(Word), P(P),
64         WordCompletionPos(StringRef::npos) {
65     OutWord = Word;
66     if (P->CompletionPos && P->CompletionPos <= Word.data() + Word.size()) {
67       if (P->CompletionPos < Word.data())
68         WordCompletionPos = 0;
69       else
70         WordCompletionPos = P->CompletionPos - Word.data();
71     }
72   }
73 
74   LexOrCompleteWord &Case(llvm::StringLiteral CaseStr, const T &Value,
75                           bool IsCompletion = true) {
76 
77     if (WordCompletionPos == StringRef::npos)
78       Switch.Case(CaseStr, Value);
79     else if (CaseStr.size() != 0 && IsCompletion && WordCompletionPos <= CaseStr.size() &&
80              CaseStr.substr(0, WordCompletionPos) ==
81                  Word.substr(0, WordCompletionPos))
82       P->Completions.push_back(LineEditor::Completion(
83           (CaseStr.substr(WordCompletionPos) + " ").str(), CaseStr));
84     return *this;
85   }
86 
87   T Default(T Value) { return Switch.Default(Value); }
88 };
89 
90 QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
91   StringRef ValStr;
92   unsigned Value = LexOrCompleteWord<unsigned>(this, ValStr)
93                        .Case("false", 0)
94                        .Case("true", 1)
95                        .Default(~0u);
96   if (Value == ~0u) {
97     return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
98   }
99   return new SetQuery<bool>(Var, Value);
100 }
101 
102 template <typename QueryType> QueryRef QueryParser::parseSetOutputKind() {
103   StringRef ValStr;
104   unsigned OutKind = LexOrCompleteWord<unsigned>(this, ValStr)
105                          .Case("diag", OK_Diag)
106                          .Case("print", OK_Print)
107                          .Case("detailed-ast", OK_DetailedAST)
108                          .Case("dump", OK_DetailedAST)
109                          .Default(~0u);
110   if (OutKind == ~0u) {
111     return new InvalidQuery(
112         "expected 'diag', 'print', 'detailed-ast' or 'dump', got '" + ValStr +
113         "'");
114   }
115 
116   switch (OutKind) {
117   case OK_DetailedAST:
118     return new QueryType(&QuerySession::DetailedASTOutput);
119   case OK_Diag:
120     return new QueryType(&QuerySession::DiagOutput);
121   case OK_Print:
122     return new QueryType(&QuerySession::PrintOutput);
123   }
124 
125   llvm_unreachable("Invalid output kind");
126 }
127 
128 QueryRef QueryParser::endQuery(QueryRef Q) {
129   const StringRef Extra = Line;
130   if (!lexWord().empty())
131     return new InvalidQuery("unexpected extra input: '" + Extra + "'");
132   return Q;
133 }
134 
135 namespace {
136 
137 enum ParsedQueryKind {
138   PQK_Invalid,
139   PQK_Comment,
140   PQK_NoOp,
141   PQK_Help,
142   PQK_Let,
143   PQK_Match,
144   PQK_Set,
145   PQK_Unlet,
146   PQK_Quit,
147   PQK_Enable,
148   PQK_Disable
149 };
150 
151 enum ParsedQueryVariable {
152   PQV_Invalid,
153   PQV_Output,
154   PQV_BindRoot,
155   PQV_PrintMatcher
156 };
157 
158 QueryRef makeInvalidQueryFromDiagnostics(const Diagnostics &Diag) {
159   std::string ErrStr;
160   llvm::raw_string_ostream OS(ErrStr);
161   Diag.printToStreamFull(OS);
162   return new InvalidQuery(OS.str());
163 }
164 
165 } // namespace
166 
167 QueryRef QueryParser::completeMatcherExpression() {
168   std::vector<MatcherCompletion> Comps = Parser::completeExpression(
169       Line, CompletionPos - Line.begin(), nullptr, &QS.NamedValues);
170   for (auto I = Comps.begin(), E = Comps.end(); I != E; ++I) {
171     Completions.push_back(LineEditor::Completion(I->TypedText, I->MatcherDecl));
172   }
173   return QueryRef();
174 }
175 
176 QueryRef QueryParser::doParse() {
177   StringRef CommandStr;
178   ParsedQueryKind QKind = LexOrCompleteWord<ParsedQueryKind>(this, CommandStr)
179                               .Case("", PQK_NoOp)
180                               .Case("#", PQK_Comment, /*IsCompletion=*/false)
181                               .Case("help", PQK_Help)
182                               .Case("l", PQK_Let, /*IsCompletion=*/false)
183                               .Case("let", PQK_Let)
184                               .Case("m", PQK_Match, /*IsCompletion=*/false)
185                               .Case("match", PQK_Match)
186                               .Case("q", PQK_Quit,  /*IsCompletion=*/false)
187                               .Case("quit", PQK_Quit)
188                               .Case("set", PQK_Set)
189                               .Case("enable", PQK_Enable)
190                               .Case("disable", PQK_Disable)
191                               .Case("unlet", PQK_Unlet)
192                               .Default(PQK_Invalid);
193 
194   switch (QKind) {
195   case PQK_Comment:
196   case PQK_NoOp:
197     return new NoOpQuery;
198 
199   case PQK_Help:
200     return endQuery(new HelpQuery);
201 
202   case PQK_Quit:
203     return endQuery(new QuitQuery);
204 
205   case PQK_Let: {
206     StringRef Name = lexWord();
207 
208     if (Name.empty())
209       return new InvalidQuery("expected variable name");
210 
211     if (CompletionPos)
212       return completeMatcherExpression();
213 
214     Diagnostics Diag;
215     ast_matchers::dynamic::VariantValue Value;
216     if (!Parser::parseExpression(Line, nullptr, &QS.NamedValues, &Value,
217                                  &Diag)) {
218       return makeInvalidQueryFromDiagnostics(Diag);
219     }
220 
221     return new LetQuery(Name, Value);
222   }
223 
224   case PQK_Match: {
225     if (CompletionPos)
226       return completeMatcherExpression();
227 
228     Diagnostics Diag;
229     auto MatcherSource = Line.trim();
230     Optional<DynTypedMatcher> Matcher = Parser::parseMatcherExpression(
231         MatcherSource, nullptr, &QS.NamedValues, &Diag);
232     if (!Matcher) {
233       return makeInvalidQueryFromDiagnostics(Diag);
234     }
235     return new MatchQuery(MatcherSource, *Matcher);
236   }
237 
238   case PQK_Set: {
239     StringRef VarStr;
240     ParsedQueryVariable Var =
241         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
242             .Case("output", PQV_Output)
243             .Case("bind-root", PQV_BindRoot)
244             .Case("print-matcher", PQV_PrintMatcher)
245             .Default(PQV_Invalid);
246     if (VarStr.empty())
247       return new InvalidQuery("expected variable name");
248     if (Var == PQV_Invalid)
249       return new InvalidQuery("unknown variable: '" + VarStr + "'");
250 
251     QueryRef Q;
252     switch (Var) {
253     case PQV_Output:
254       Q = parseSetOutputKind<SetExclusiveOutputQuery>();
255       break;
256     case PQV_BindRoot:
257       Q = parseSetBool(&QuerySession::BindRoot);
258       break;
259     case PQV_PrintMatcher:
260       Q = parseSetBool(&QuerySession::PrintMatcher);
261       break;
262     case PQV_Invalid:
263       llvm_unreachable("Invalid query kind");
264     }
265 
266     return endQuery(Q);
267   }
268   case PQK_Enable:
269   case PQK_Disable: {
270     StringRef VarStr;
271     ParsedQueryVariable Var =
272         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
273             .Case("output", PQV_Output)
274             .Default(PQV_Invalid);
275     if (VarStr.empty())
276       return new InvalidQuery("expected variable name");
277     if (Var == PQV_Invalid)
278       return new InvalidQuery("unknown variable: '" + VarStr + "'");
279 
280     QueryRef Q;
281 
282     if (QKind == PQK_Enable)
283       Q = parseSetOutputKind<EnableOutputQuery>();
284     else if (QKind == PQK_Disable)
285       Q = parseSetOutputKind<DisableOutputQuery>();
286     else
287       llvm_unreachable("Invalid query kind");
288     return endQuery(Q);
289   }
290 
291   case PQK_Unlet: {
292     StringRef Name = lexWord();
293 
294     if (Name.empty())
295       return new InvalidQuery("expected variable name");
296 
297     return endQuery(new LetQuery(Name, VariantValue()));
298   }
299 
300   case PQK_Invalid:
301     return new InvalidQuery("unknown command: " + CommandStr);
302   }
303 
304   llvm_unreachable("Invalid query kind");
305 }
306 
307 QueryRef QueryParser::parse(StringRef Line, const QuerySession &QS) {
308   return QueryParser(Line, QS).doParse();
309 }
310 
311 std::vector<LineEditor::Completion>
312 QueryParser::complete(StringRef Line, size_t Pos, const QuerySession &QS) {
313   QueryParser P(Line, QS);
314   P.CompletionPos = Line.data() + Pos;
315 
316   P.doParse();
317   return P.Completions;
318 }
319 
320 } // namespace query
321 } // namespace clang
322