[clangd] Cleanup the duplicated getTokenRange.

[hokein]

Summary

Also lift it to SourceCode.h, so that it can be used in other places
(semantic code highlighting).

[kadircet]

clang-tools-extra/clangd/XRefs.cpp

926

nit: move declaration into if body?

[hokein]

Address review comments.

clang-tools-extra/clangd/SourceCode.h

 /// Turn an offset in Code into a [line, column] pair.
 /// The offset must be in range [0, Code.size()].
 Position offsetToPosition(llvm::StringRef Code, size_t Offset);
 
 /// Turn a SourceLocation into a [line, column] pair.
 /// FIXME: This should return an error if the location is invalid.
 Position sourceLocToPosition(const SourceManager &SM, SourceLocation Loc);
 
+/// Returns the taken range at \p TokLoc.
+llvm::Optional<Range> getTokenRange(const SourceManager &SM,
+                                    const LangOptions &LangOpts,
+                                    SourceLocation TokLoc);
+
 /// Return the file location, corresponding to \p P. Note that one should take
 /// care to avoid comparing the result with expansion locations.
 llvm::Expected<SourceLocation> sourceLocationInMainFile(const SourceManager &SM,
                                                         Position P);
 
 /// Turns a token range into a half-open range and checks its correctness.
 /// The resulting range will have only valid source location on both sides, both
 /// of which are file locations.

clang-tools-extra/clangd/SourceCode.cpp

Position sourceLocToPosition(const SourceManager &SM, SourceLocation Loc) {
   if (!Invalid) {
     auto ColumnInBytes = SM.getColumnNumber(FID, Offset) - 1;
     auto LineSoFar = Code.substr(Offset - ColumnInBytes, ColumnInBytes);
     P.character = lspLength(LineSoFar);
   }
   return P;
 }
 
+llvm::Optional<Range> getTokenRange(const SourceManager &SM,
+                                    const LangOptions &LangOpts,
+                                    SourceLocation TokLoc) {
+  if (!TokLoc.isValid())
+    return llvm::None;
+  SourceLocation End = Lexer::getLocForEndOfToken(TokLoc, 0, SM, LangOpts);
+  if (!End.isValid())
+    return llvm::None;
+  return halfOpenToRange(SM, CharSourceRange::getCharRange(TokLoc, End));
+}
+
 bool isValidFileRange(const SourceManager &Mgr, SourceRange R) {
   if (!R.getBegin().isValid() || !R.getEnd().isValid())
     return false;
 
   FileID BeginFID;
   size_t BeginOffset = 0;
   std::tie(BeginFID, BeginOffset) = Mgr.getDecomposedLoc(R.getBegin());
 

clang-tools-extra/clangd/XRefs.cpp

IdentifiedSymbol getSymbolAtPosition(ParsedAST &AST, SourceLocation Pos) {
   IndexOpts.IndexParametersInDeclarations = true;
   IndexOpts.IndexTemplateParameters = true;
   indexTopLevelDecls(AST.getASTContext(), AST.getPreprocessor(),
                      AST.getLocalTopLevelDecls(), DeclMacrosFinder, IndexOpts);
 
   return {DeclMacrosFinder.getFoundDecls(), DeclMacrosFinder.takeMacroInfos()};
 }
 
-Range getTokenRange(ASTContext &AST, SourceLocation TokLoc) {
-  const SourceManager &SourceMgr = AST.getSourceManager();
-  SourceLocation LocEnd =
-      Lexer::getLocForEndOfToken(TokLoc, 0, SourceMgr, AST.getLangOpts());
-  return {sourceLocToPosition(SourceMgr, TokLoc),
-          sourceLocToPosition(SourceMgr, LocEnd)};
-}
-
 llvm::Optional<Location> makeLocation(ASTContext &AST, SourceLocation TokLoc,
                                       llvm::StringRef TUPath) {
   const SourceManager &SourceMgr = AST.getSourceManager();
   const FileEntry *F = SourceMgr.getFileEntryForID(SourceMgr.getFileID(TokLoc));
   if (!F)
     return None;
   auto FilePath = getCanonicalPath(F, SourceMgr);
   if (!FilePath) {
     log("failed to get path!");
     return None;
   }
+  if (auto Range =
+          getTokenRange(AST.getSourceManager(), AST.getLangOpts(), TokLoc)) {
     Location L;
     L.uri = URIForFile::canonicalize(*FilePath, TUPath);
-  L.range = getTokenRange(AST, TokLoc);
+    L.range = *Range;
     return L;
   }
+  return None;
+}
 
 } // namespace
 
 std::vector<LocatedSymbol> locateSymbolAt(ParsedAST &AST, Position Pos,
                                           const SymbolIndex *Index) {
   const auto &SM = AST.getSourceManager();
   auto MainFilePath =
       getCanonicalPath(SM.getFileEntryForID(SM.getMainFileID()), SM);
std::vector<DocumentHighlight> findDocumentHighlights(ParsedAST &AST,
   const SourceManager &SM = AST.getSourceManager();
   auto Symbols = getSymbolAtPosition(
       AST, getBeginningOfIdentifier(AST, Pos, SM.getMainFileID()));
   auto References = findRefs(Symbols.Decls, AST);
 
   std::vector<DocumentHighlight> Result;
   for (const auto &Ref : References) {
     DocumentHighlight DH;
-    DH.range = getTokenRange(AST.getASTContext(), Ref.Loc);
+    if (auto Range =
+            getTokenRange(AST.getASTContext().getSourceManager(),
+                          AST.getASTContext().getLangOpts(), Ref.Loc)) {
+      DH.range = *Range;
       if (Ref.Role & index::SymbolRoleSet(index::SymbolRole::Write))
         DH.kind = DocumentHighlightKind::Write;
       else if (Ref.Role & index::SymbolRoleSet(index::SymbolRole::Read))
         DH.kind = DocumentHighlightKind::Read;
       else
         DH.kind = DocumentHighlightKind::Text;
       Result.push_back(std::move(DH));
     }
+  }
   return Result;
 }
 
 static PrintingPolicy printingPolicyForDecls(PrintingPolicy Base) {
   PrintingPolicy Policy(Base);
 
   Policy.AnonymousTagLocations = false;
   Policy.TerseOutput = true;
if (const auto TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
       }
     }
     TempParameters.push_back(std::move(P));
   }
 
   return TempParameters;
 }
 
-static llvm::Optional<Range> getTokenRange(SourceLocation Loc,
-                                           const ASTContext &Ctx) {
-  if (!Loc.isValid())
-    return llvm::None;
-  SourceLocation End = Lexer::getLocForEndOfToken(
-      Loc, 0, Ctx.getSourceManager(), Ctx.getLangOpts());
-  if (!End.isValid())
-    return llvm::None;
-  return halfOpenToRange(Ctx.getSourceManager(),
-                         CharSourceRange::getCharRange(Loc, End));
-}
-
 static const FunctionDecl *getUnderlyingFunction(const Decl *D) {
   // Extract lambda from variables.
   if (const VarDecl *VD = llvm::dyn_cast<VarDecl>(D)) {
     auto QT = VD->getType();
     if (!QT.isNull()) {
       while (!QT->getPointeeType().isNull())
         QT = QT->getPointeeType();
 
llvm::Optional<HoverInfo> getHover(ParsedAST &AST, Position Pos,
   }
 
   auto Replacements = format::reformat(
       Style, HI->Definition, tooling::Range(0, HI->Definition.size()));
   if (auto Formatted =
           tooling::applyAllReplacements(HI->Definition, Replacements))
     HI->Definition = *Formatted;
 
-  HI->SymRange = getTokenRange(SourceLocationBeg, AST.getASTContext());
+  HI->SymRange =
+      getTokenRange(AST.getASTContext().getSourceManager(),
+                    AST.getASTContext().getLangOpts(), SourceLocationBeg);
   return HI;
 }
 
 std::vector<Location> findReferences(ParsedAST &AST, Position Pos,
                                      uint32_t Limit, const SymbolIndex *Index) {
   if (!Limit)
     Limit = std::numeric_limits<uint32_t>::max();
   std::vector<Location> Results;
   const SourceManager &SM = AST.getSourceManager();
   auto MainFilePath =
       getCanonicalPath(SM.getFileEntryForID(SM.getMainFileID()), SM);
   if (!MainFilePath) {
     elog("Failed to get a path for the main file, so no references");
     return Results;
   }
   auto Loc = getBeginningOfIdentifier(AST, Pos, SM.getMainFileID());
   auto Symbols = getSymbolAtPosition(AST, Loc);
 
   // We traverse the AST to find references in the main file.
   // TODO: should we handle macros, too?
   auto MainFileRefs = findRefs(Symbols.Decls, AST);
   for (const auto &Ref : MainFileRefs) {
     Location Result;
-    Result.range = getTokenRange(AST.getASTContext(), Ref.Loc);
+    if (auto Range =
+            getTokenRange(AST.getASTContext().getSourceManager(),
+                          AST.getASTContext().getLangOpts(), Ref.Loc)) {
+      Result.range = *Range;
       Result.uri = URIForFile::canonicalize(*MainFilePath, *MainFilePath);
       Results.push_back(std::move(Result));
     }
+  }
 
   // Now query the index for references from other files.
   if (Index && Results.size() < Limit) {
     RefsRequest Req;
     Req.Limit = Limit;
 
     for (const Decl *D : Symbols.Decls) {
       // Not all symbols can be referenced from outside (e.g. function-locals).