clang-tools-extra/clang-query/QueryParser.cpp

   1 //===---- QueryParser.cpp - clang-query command parser --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "QueryParser.h"
  10 #include "Query.h"
  11 #include "QuerySession.h"
  12 #include "clang/ASTMatchers/Dynamic/Parser.h"
  13 #include "clang/Basic/CharInfo.h"
  14 #include "llvm/ADT/StringRef.h"
  15 #include "llvm/ADT/StringSwitch.h"
  16 #include <optional>
  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   // Don't trim newlines.
  31   Line = Line.ltrim(" \t\v\f\r");
  32
  33   if (Line.empty())
  34     // Even though the Line is empty, it contains a pointer and
  35     // a (zero) length. The pointer is used in the LexOrCompleteWord
  36     // code completion.
  37     return Line;
  38
  39   StringRef Word;
  40   if (Line.front() == '#')
  41     Word = Line.substr(0, 1);
  42   else
  43     Word = Line.take_until(isWhitespace);
  44
  45   Line = Line.drop_front(Word.size());
  46   return Word;
  47 }
  48
  49 // This is the StringSwitch-alike used by lexOrCompleteWord below. See that
  50 // function for details.
  51 template <typename T> struct QueryParser::LexOrCompleteWord {
  52   StringRef Word;
  53   StringSwitch<T> Switch;
  54
  55   QueryParser *P;
  56   // Set to the completion point offset in Word, or StringRef::npos if
  57   // completion point not in Word.
  58   size_t WordCompletionPos;
  59
  60   // Lexes a word and stores it in Word. Returns a LexOrCompleteWord<T> object
  61   // that can be used like a llvm::StringSwitch<T>, but adds cases as possible
  62   // completions if the lexed word contains the completion point.
  63   LexOrCompleteWord(QueryParser *P, StringRef &OutWord)
  64       : Word(P->lexWord()), Switch(Word), P(P),
  65         WordCompletionPos(StringRef::npos) {
  66     OutWord = Word;
  67     if (P->CompletionPos && P->CompletionPos <= Word.data() + Word.size()) {
  68       if (P->CompletionPos < Word.data())
  69         WordCompletionPos = 0;
  70       else
  71         WordCompletionPos = P->CompletionPos - Word.data();
  72     }
  73   }
  74
  75   LexOrCompleteWord &Case(llvm::StringLiteral CaseStr, const T &Value,
  76                           bool IsCompletion = true) {
  77
  78     if (WordCompletionPos == StringRef::npos)
  79       Switch.Case(CaseStr, Value);
  80     else if (CaseStr.size() != 0 && IsCompletion && WordCompletionPos <= CaseStr.size() &&
  81              CaseStr.substr(0, WordCompletionPos) ==
  82                  Word.substr(0, WordCompletionPos))
  83       P->Completions.push_back(LineEditor::Completion(
  84           (CaseStr.substr(WordCompletionPos) + " ").str(),
  85           std::string(CaseStr)));
  86     return *this;
  87   }
  88
  89   T Default(T Value) { return Switch.Default(Value); }
  90 };
  91
  92 QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
  93   StringRef ValStr;
  94   unsigned Value = LexOrCompleteWord<unsigned>(this, ValStr)
  95                        .Case("false", 0)
  96                        .Case("true", 1)
  97                        .Default(~0u);
  98   if (Value == ~0u) {
  99     return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
 100   }
 101   return new SetQuery<bool>(Var, Value);
 102 }
 103
 104 template <typename QueryType> QueryRef QueryParser::parseSetOutputKind() {
 105   StringRef ValStr;
 106   unsigned OutKind = LexOrCompleteWord<unsigned>(this, ValStr)
 107                          .Case("diag", OK_Diag)
 108                          .Case("print", OK_Print)
 109                          .Case("detailed-ast", OK_DetailedAST)
 110                          .Case("dump", OK_DetailedAST)
 111                          .Default(~0u);
 112   if (OutKind == ~0u) {
 113     return new InvalidQuery("expected 'diag', 'print', 'detailed-ast' or "
 114                             "'dump', got '" +
 115                             ValStr + "'");
 116   }
 117
 118   switch (OutKind) {
 119   case OK_DetailedAST:
 120     return new QueryType(&QuerySession::DetailedASTOutput);
 121   case OK_Diag:
 122     return new QueryType(&QuerySession::DiagOutput);
 123   case OK_Print:
 124     return new QueryType(&QuerySession::PrintOutput);
 125   }
 126
 127   llvm_unreachable("Invalid output kind");
 128 }
 129
 130 QueryRef QueryParser::parseSetTraversalKind(TraversalKind QuerySession::*Var) {
 131   StringRef ValStr;
 132   unsigned Value =
 133       LexOrCompleteWord<unsigned>(this, ValStr)
 134           .Case("AsIs", TK_AsIs)
 135           .Case("IgnoreUnlessSpelledInSource", TK_IgnoreUnlessSpelledInSource)
 136           .Default(~0u);
 137   if (Value == ~0u) {
 138     return new InvalidQuery("expected traversal kind, got '" + ValStr + "'");
 139   }
 140   return new SetQuery<TraversalKind>(Var, static_cast<TraversalKind>(Value));
 141 }
 142
 143 QueryRef QueryParser::endQuery(QueryRef Q) {
 144   StringRef Extra = Line;
 145   StringRef ExtraTrimmed = Extra.ltrim(" \t\v\f\r");
 146
 147   if (ExtraTrimmed.starts_with('\n') || ExtraTrimmed.starts_with("\r\n"))
 148     Q->RemainingContent = Extra;
 149   else {
 150     StringRef TrailingWord = lexWord();
 151     if (TrailingWord.starts_with('#')) {
 152       Line = Line.drop_until([](char c) { return c == '\n'; });
 153       Line = Line.drop_while([](char c) { return c == '\n'; });
 154       return endQuery(Q);
 155     }
 156     if (!TrailingWord.empty()) {
 157       return new InvalidQuery("unexpected extra input: '" + Extra + "'");
 158     }
 159   }
 160   return Q;
 161 }
 162
 163 namespace {
 164
 165 enum ParsedQueryKind {
 166   PQK_Invalid,
 167   PQK_Comment,
 168   PQK_NoOp,
 169   PQK_Help,
 170   PQK_Let,
 171   PQK_Match,
 172   PQK_Set,
 173   PQK_Unlet,
 174   PQK_Quit,
 175   PQK_Enable,
 176   PQK_Disable,
 177   PQK_File
 178 };
 179
 180 enum ParsedQueryVariable {
 181   PQV_Invalid,
 182   PQV_Output,
 183   PQV_BindRoot,
 184   PQV_PrintMatcher,
 185   PQV_EnableProfile,
 186   PQV_Traversal
 187 };
 188
 189 QueryRef makeInvalidQueryFromDiagnostics(const Diagnostics &Diag) {
 190   std::string ErrStr;
 191   llvm::raw_string_ostream OS(ErrStr);
 192   Diag.printToStreamFull(OS);
 193   return new InvalidQuery(OS.str());
 194 }
 195
 196 } // namespace
 197
 198 QueryRef QueryParser::completeMatcherExpression() {
 199   std::vector<MatcherCompletion> Comps = Parser::completeExpression(
 200       Line, CompletionPos - Line.begin(), nullptr, &QS.NamedValues);
 201   for (auto I = Comps.begin(), E = Comps.end(); I != E; ++I) {
 202     Completions.push_back(LineEditor::Completion(I->TypedText, I->MatcherDecl));
 203   }
 204   return QueryRef();
 205 }
 206
 207 QueryRef QueryParser::doParse() {
 208   StringRef CommandStr;
 209   ParsedQueryKind QKind = LexOrCompleteWord<ParsedQueryKind>(this, CommandStr)
 210                               .Case("", PQK_NoOp)
 211                               .Case("#", PQK_Comment, /*IsCompletion=*/false)
 212                               .Case("help", PQK_Help)
 213                               .Case("l", PQK_Let, /*IsCompletion=*/false)
 214                               .Case("let", PQK_Let)
 215                               .Case("m", PQK_Match, /*IsCompletion=*/false)
 216                               .Case("match", PQK_Match)
 217                               .Case("q", PQK_Quit, /*IsCompletion=*/false)
 218                               .Case("quit", PQK_Quit)
 219                               .Case("set", PQK_Set)
 220                               .Case("enable", PQK_Enable)
 221                               .Case("disable", PQK_Disable)
 222                               .Case("unlet", PQK_Unlet)
 223                               .Case("f", PQK_File, /*IsCompletion=*/false)
 224                               .Case("file", PQK_File)
 225                               .Default(PQK_Invalid);
 226
 227   switch (QKind) {
 228   case PQK_Comment:
 229   case PQK_NoOp:
 230     Line = Line.drop_until([](char c) { return c == '\n'; });
 231     Line = Line.drop_while([](char c) { return c == '\n'; });
 232     if (Line.empty())
 233       return new NoOpQuery;
 234     return doParse();
 235
 236   case PQK_Help:
 237     return endQuery(new HelpQuery);
 238
 239   case PQK_Quit:
 240     return endQuery(new QuitQuery);
 241
 242   case PQK_Let: {
 243     StringRef Name = lexWord();
 244
 245     if (Name.empty())
 246       return new InvalidQuery("expected variable name");
 247
 248     if (CompletionPos)
 249       return completeMatcherExpression();
 250
 251     Diagnostics Diag;
 252     ast_matchers::dynamic::VariantValue Value;
 253     if (!Parser::parseExpression(Line, nullptr, &QS.NamedValues, &Value,
 254                                  &Diag)) {
 255       return makeInvalidQueryFromDiagnostics(Diag);
 256     }
 257
 258     auto *Q = new LetQuery(Name, Value);
 259     Q->RemainingContent = Line;
 260     return Q;
 261   }
 262
 263   case PQK_Match: {
 264     if (CompletionPos)
 265       return completeMatcherExpression();
 266
 267     Diagnostics Diag;
 268     auto MatcherSource = Line.ltrim();
 269     auto OrigMatcherSource = MatcherSource;
 270     std::optional<DynTypedMatcher> Matcher = Parser::parseMatcherExpression(
 271         MatcherSource, nullptr, &QS.NamedValues, &Diag);
 272     if (!Matcher) {
 273       return makeInvalidQueryFromDiagnostics(Diag);
 274     }
 275     auto ActualSource = OrigMatcherSource.slice(0, OrigMatcherSource.size() -
 276                                                        MatcherSource.size());
 277     auto *Q = new MatchQuery(ActualSource, *Matcher);
 278     Q->RemainingContent = MatcherSource;
 279     return Q;
 280   }
 281
 282   case PQK_Set: {
 283     StringRef VarStr;
 284     ParsedQueryVariable Var =
 285         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
 286             .Case("output", PQV_Output)
 287             .Case("bind-root", PQV_BindRoot)
 288             .Case("print-matcher", PQV_PrintMatcher)
 289             .Case("enable-profile", PQV_EnableProfile)
 290             .Case("traversal", PQV_Traversal)
 291             .Default(PQV_Invalid);
 292     if (VarStr.empty())
 293       return new InvalidQuery("expected variable name");
 294     if (Var == PQV_Invalid)
 295       return new InvalidQuery("unknown variable: '" + VarStr + "'");
 296
 297     QueryRef Q;
 298     switch (Var) {
 299     case PQV_Output:
 300       Q = parseSetOutputKind<SetExclusiveOutputQuery>();
 301       break;
 302     case PQV_BindRoot:
 303       Q = parseSetBool(&QuerySession::BindRoot);
 304       break;
 305     case PQV_PrintMatcher:
 306       Q = parseSetBool(&QuerySession::PrintMatcher);
 307       break;
 308     case PQV_EnableProfile:
 309       Q = parseSetBool(&QuerySession::EnableProfile);
 310       break;
 311     case PQV_Traversal:
 312       Q = parseSetTraversalKind(&QuerySession::TK);
 313       break;
 314     case PQV_Invalid:
 315       llvm_unreachable("Invalid query kind");
 316     }
 317
 318     return endQuery(Q);
 319   }
 320   case PQK_Enable:
 321   case PQK_Disable: {
 322     StringRef VarStr;
 323     ParsedQueryVariable Var =
 324         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
 325             .Case("output", PQV_Output)
 326             .Default(PQV_Invalid);
 327     if (VarStr.empty())
 328       return new InvalidQuery("expected variable name");
 329     if (Var == PQV_Invalid)
 330       return new InvalidQuery("unknown variable: '" + VarStr + "'");
 331
 332     QueryRef Q;
 333
 334     if (QKind == PQK_Enable)
 335       Q = parseSetOutputKind<EnableOutputQuery>();
 336     else if (QKind == PQK_Disable)
 337       Q = parseSetOutputKind<DisableOutputQuery>();
 338     else
 339       llvm_unreachable("Invalid query kind");
 340     return endQuery(Q);
 341   }
 342
 343   case PQK_Unlet: {
 344     StringRef Name = lexWord();
 345
 346     if (Name.empty())
 347       return new InvalidQuery("expected variable name");
 348
 349     return endQuery(new LetQuery(Name, VariantValue()));
 350   }
 351
 352   case PQK_File:
 353     return new FileQuery(Line);
 354
 355   case PQK_Invalid:
 356     return new InvalidQuery("unknown command: " + CommandStr);
 357   }
 358
 359   llvm_unreachable("Invalid query kind");
 360 }
 361
 362 QueryRef QueryParser::parse(StringRef Line, const QuerySession &QS) {
 363   return QueryParser(Line, QS).doParse();
 364 }
 365
 366 std::vector<LineEditor::Completion>
 367 QueryParser::complete(StringRef Line, size_t Pos, const QuerySession &QS) {
 368   QueryParser P(Line, QS);
 369   P.CompletionPos = Line.data() + Pos;
 370
 371   P.doParse();
 372   return P.Completions;
 373 }
 374
 375 } // namespace query
 376 } // namespace clang