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 
18 #include <set>
19 
20 using namespace llvm;
21 using namespace clang::ast_matchers::dynamic;
22 
23 namespace clang {
24 namespace query {
25 
26 // Lex any amount of whitespace followed by a "word" (any sequence of
27 // non-whitespace characters) from the start of region [Begin,End).  If no word
28 // is found before End, return StringRef().  Begin is adjusted to exclude the
29 // lexed region.
30 StringRef QueryParser::lexWord() {
31   while (true) {
32     if (Begin == End)
33       return StringRef(Begin, 0);
34 
35     if (!isWhitespace(*Begin))
36       break;
37 
38     ++Begin;
39   }
40 
41   const char *WordBegin = Begin;
42 
43   while (true) {
44     ++Begin;
45 
46     if (Begin == End || isWhitespace(*Begin))
47       return StringRef(WordBegin, Begin - WordBegin);
48   }
49 }
50 
51 // This is the StringSwitch-alike used by lexOrCompleteWord below. See that
52 // function for details.
53 template <typename T> struct QueryParser::LexOrCompleteWord {
54   StringSwitch<T> Switch;
55 
56   QueryParser *P;
57   StringRef Word;
58   // Set to the completion point offset in Word, or StringRef::npos if
59   // completion point not in Word.
60   size_t WordCompletionPos;
61 
62   LexOrCompleteWord(QueryParser *P, StringRef Word, size_t WCP)
63       : Switch(Word), P(P), Word(Word), WordCompletionPos(WCP) {}
64 
65   template <unsigned N>
66   LexOrCompleteWord &Case(const char (&S)[N], const T &Value,
67                           bool IsCompletion = true) {
68     StringRef CaseStr(S, N - 1);
69 
70     if (WordCompletionPos == StringRef::npos)
71       Switch.Case(S, Value);
72     else if (N != 1 && IsCompletion && WordCompletionPos <= CaseStr.size() &&
73              CaseStr.substr(0, WordCompletionPos) ==
74                  Word.substr(0, WordCompletionPos))
75       P->Completions.push_back(LineEditor::Completion(
76           (CaseStr.substr(WordCompletionPos) + " ").str(), CaseStr));
77     return *this;
78   }
79 
80   T Default(const T& Value) const {
81     return Switch.Default(Value);
82   }
83 };
84 
85 // Lexes a word and stores it in Word. Returns a LexOrCompleteWord<T> object
86 // that can be used like a llvm::StringSwitch<T>, but adds cases as possible
87 // completions if the lexed word contains the completion point.
88 template <typename T>
89 QueryParser::LexOrCompleteWord<T>
90 QueryParser::lexOrCompleteWord(StringRef &Word) {
91   Word = lexWord();
92   size_t WordCompletionPos = StringRef::npos;
93   if (CompletionPos && CompletionPos <= Word.data() + Word.size()) {
94     if (CompletionPos < Word.data())
95       WordCompletionPos = 0;
96     else
97       WordCompletionPos = CompletionPos - Word.data();
98   }
99   return LexOrCompleteWord<T>(this, Word, WordCompletionPos);
100 }
101 
102 QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
103   StringRef ValStr;
104   unsigned Value = lexOrCompleteWord<unsigned>(ValStr)
105                       .Case("false", 0)
106                       .Case("true", 1)
107                       .Default(~0u);
108   if (Value == ~0u) {
109     return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
110   }
111   return new SetQuery<bool>(Var, Value);
112 }
113 
114 QueryRef QueryParser::parseSetOutputKind() {
115   StringRef ValStr;
116   unsigned OutKind = lexOrCompleteWord<unsigned>(ValStr)
117                          .Case("diag", OK_Diag)
118                          .Case("print", OK_Print)
119                          .Case("dump", OK_Dump)
120                          .Default(~0u);
121   if (OutKind == ~0u) {
122     return new InvalidQuery("expected 'diag', 'print' or 'dump', got '" +
123                             ValStr + "'");
124   }
125   return new SetQuery<OutputKind>(&QuerySession::OutKind, OutputKind(OutKind));
126 }
127 
128 QueryRef QueryParser::endQuery(QueryRef Q) {
129   const char *Extra = Begin;
130   if (!lexWord().empty())
131     return new InvalidQuery("unexpected extra input: '" +
132                             StringRef(Extra, End - Extra) + "'");
133   return Q;
134 }
135 
136 enum ParsedQueryKind {
137   PQK_Invalid,
138   PQK_NoOp,
139   PQK_Help,
140   PQK_Match,
141   PQK_Set
142 };
143 
144 enum ParsedQueryVariable {
145   PQV_Invalid,
146   PQV_Output,
147   PQV_BindRoot
148 };
149 
150 QueryRef QueryParser::doParse() {
151   StringRef CommandStr;
152   ParsedQueryKind QKind = lexOrCompleteWord<ParsedQueryKind>(CommandStr)
153                               .Case("", PQK_NoOp)
154                               .Case("help", PQK_Help)
155                               .Case("m", PQK_Match, /*IsCompletion=*/false)
156                               .Case("match", PQK_Match)
157                               .Case("set", PQK_Set)
158                               .Default(PQK_Invalid);
159 
160   switch (QKind) {
161   case PQK_NoOp:
162     return new NoOpQuery;
163 
164   case PQK_Help:
165     return endQuery(new HelpQuery);
166 
167   case PQK_Match: {
168     if (CompletionPos) {
169       std::vector<MatcherCompletion> Comps = Parser::completeExpression(
170           StringRef(Begin, End - Begin), CompletionPos - Begin);
171       for (std::vector<MatcherCompletion>::iterator I = Comps.begin(),
172                                                     E = Comps.end();
173            I != E; ++I) {
174         Completions.push_back(
175             LineEditor::Completion(I->TypedText, I->MatcherDecl));
176       }
177       return QueryRef();
178     } else {
179       Diagnostics Diag;
180       Optional<DynTypedMatcher> Matcher =
181           Parser::parseMatcherExpression(StringRef(Begin, End - Begin), &Diag);
182       if (!Matcher) {
183         std::string ErrStr;
184         llvm::raw_string_ostream OS(ErrStr);
185         Diag.printToStreamFull(OS);
186         return new InvalidQuery(OS.str());
187       }
188       return new MatchQuery(*Matcher);
189     }
190   }
191 
192   case PQK_Set: {
193     StringRef VarStr;
194     ParsedQueryVariable Var = lexOrCompleteWord<ParsedQueryVariable>(VarStr)
195                                   .Case("output", PQV_Output)
196                                   .Case("bind-root", PQV_BindRoot)
197                                   .Default(PQV_Invalid);
198     if (VarStr.empty())
199       return new InvalidQuery("expected variable name");
200     if (Var == PQV_Invalid)
201       return new InvalidQuery("unknown variable: '" + VarStr + "'");
202 
203     QueryRef Q;
204     switch (Var) {
205     case PQV_Output:
206       Q = parseSetOutputKind();
207       break;
208     case PQV_BindRoot:
209       Q = parseSetBool(&QuerySession::BindRoot);
210       break;
211     case PQV_Invalid:
212       llvm_unreachable("Invalid query kind");
213     }
214 
215     return endQuery(Q);
216   }
217 
218   case PQK_Invalid:
219     return new InvalidQuery("unknown command: " + CommandStr);
220   }
221 
222   llvm_unreachable("Invalid query kind");
223 }
224 
225 QueryRef QueryParser::parse(StringRef Line) {
226   return QueryParser(Line).doParse();
227 }
228 
229 std::vector<LineEditor::Completion> QueryParser::complete(StringRef Line,
230                                                           size_t Pos) {
231   QueryParser P(Line);
232   P.CompletionPos = Line.data() + Pos;
233 
234   P.doParse();
235   return P.Completions;
236 }
237 
238 } // namespace query
239 } // namespace clang
240