llvm-project/clang-tools-extra/clangd/XRefs.cpp

665 lines
23 KiB
C++
Raw Normal View History

//===--- XRefs.cpp ----------------------------------------------*- C++-*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===---------------------------------------------------------------------===//
#include "XRefs.h"
#include "AST.h"
#include "Logger.h"
#include "SourceCode.h"
#include "URI.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Index/IndexDataConsumer.h"
#include "clang/Index/IndexingAction.h"
#include "clang/Index/USRGeneration.h"
#include "llvm/Support/Path.h"
namespace clang {
namespace clangd {
using namespace llvm;
namespace {
// Get the definition from a given declaration `D`.
// Return nullptr if no definition is found, or the declaration type of `D` is
// not supported.
const Decl *getDefinition(const Decl *D) {
assert(D);
if (const auto *TD = dyn_cast<TagDecl>(D))
return TD->getDefinition();
else if (const auto *VD = dyn_cast<VarDecl>(D))
return VD->getDefinition();
else if (const auto *FD = dyn_cast<FunctionDecl>(D))
return FD->getDefinition();
return nullptr;
}
// Convert a SymbolLocation to LSP's Location.
// HintPath is used to resolve the path of URI.
// FIXME: figure out a good home for it, and share the implementation with
// FindSymbols.
llvm::Optional<Location> toLSPLocation(const SymbolLocation &Loc,
llvm::StringRef HintPath) {
if (!Loc)
return llvm::None;
auto Uri = URI::parse(Loc.FileURI);
if (!Uri) {
log("Could not parse URI: {0}", Loc.FileURI);
return llvm::None;
}
auto Path = URI::resolve(*Uri, HintPath);
if (!Path) {
log("Could not resolve URI: {0}", Loc.FileURI);
return llvm::None;
}
Location LSPLoc;
LSPLoc.uri = URIForFile(*Path);
LSPLoc.range.start.line = Loc.Start.Line;
LSPLoc.range.start.character = Loc.Start.Column;
LSPLoc.range.end.line = Loc.End.Line;
LSPLoc.range.end.character = Loc.End.Column;
return LSPLoc;
}
struct MacroDecl {
StringRef Name;
const MacroInfo *Info;
};
/// Finds declarations locations that a given source location refers to.
class DeclarationAndMacrosFinder : public index::IndexDataConsumer {
std::vector<const Decl *> Decls;
std::vector<MacroDecl> MacroInfos;
const SourceLocation &SearchedLocation;
const ASTContext &AST;
Preprocessor &PP;
public:
DeclarationAndMacrosFinder(raw_ostream &OS,
const SourceLocation &SearchedLocation,
ASTContext &AST, Preprocessor &PP)
: SearchedLocation(SearchedLocation), AST(AST), PP(PP) {}
std::vector<const Decl *> takeDecls() {
// Don't keep the same declaration multiple times.
// This can happen when nodes in the AST are visited twice.
std::sort(Decls.begin(), Decls.end());
auto Last = std::unique(Decls.begin(), Decls.end());
Decls.erase(Last, Decls.end());
return std::move(Decls);
}
std::vector<MacroDecl> takeMacroInfos() {
// Don't keep the same Macro info multiple times.
std::sort(MacroInfos.begin(), MacroInfos.end(),
[](const MacroDecl &Left, const MacroDecl &Right) {
return Left.Info < Right.Info;
});
auto Last = std::unique(MacroInfos.begin(), MacroInfos.end(),
[](const MacroDecl &Left, const MacroDecl &Right) {
return Left.Info == Right.Info;
});
MacroInfos.erase(Last, MacroInfos.end());
return std::move(MacroInfos);
}
bool
handleDeclOccurence(const Decl *D, index::SymbolRoleSet Roles,
ArrayRef<index::SymbolRelation> Relations,
SourceLocation Loc,
index::IndexDataConsumer::ASTNodeInfo ASTNode) override {
if (Loc == SearchedLocation) {
// Find and add definition declarations (for GoToDefinition).
// We don't use parameter `D`, as Parameter `D` is the canonical
// declaration, which is the first declaration of a redeclarable
// declaration, and it could be a forward declaration.
if (const auto *Def = getDefinition(D)) {
Decls.push_back(Def);
} else {
// Couldn't find a definition, fall back to use `D`.
Decls.push_back(D);
}
}
return true;
}
private:
void finish() override {
// Also handle possible macro at the searched location.
Token Result;
auto &Mgr = AST.getSourceManager();
if (!Lexer::getRawToken(Mgr.getSpellingLoc(SearchedLocation), Result, Mgr,
AST.getLangOpts(), false)) {
if (Result.is(tok::raw_identifier)) {
PP.LookUpIdentifierInfo(Result);
}
IdentifierInfo *IdentifierInfo = Result.getIdentifierInfo();
if (IdentifierInfo && IdentifierInfo->hadMacroDefinition()) {
std::pair<FileID, unsigned int> DecLoc =
Mgr.getDecomposedExpansionLoc(SearchedLocation);
// Get the definition just before the searched location so that a macro
// referenced in a '#undef MACRO' can still be found.
SourceLocation BeforeSearchedLocation = Mgr.getMacroArgExpandedLocation(
Mgr.getLocForStartOfFile(DecLoc.first)
.getLocWithOffset(DecLoc.second - 1));
MacroDefinition MacroDef =
PP.getMacroDefinitionAtLoc(IdentifierInfo, BeforeSearchedLocation);
MacroInfo *MacroInf = MacroDef.getMacroInfo();
if (MacroInf) {
MacroInfos.push_back(MacroDecl{IdentifierInfo->getName(), MacroInf});
assert(Decls.empty());
}
}
}
}
};
struct IdentifiedSymbol {
std::vector<const Decl *> Decls;
std::vector<MacroDecl> Macros;
};
IdentifiedSymbol getSymbolAtPosition(ParsedAST &AST, SourceLocation Pos) {
auto DeclMacrosFinder = DeclarationAndMacrosFinder(
llvm::errs(), Pos, AST.getASTContext(), AST.getPreprocessor());
index::IndexingOptions IndexOpts;
IndexOpts.SystemSymbolFilter =
index::IndexingOptions::SystemSymbolFilterKind::All;
IndexOpts.IndexFunctionLocals = true;
indexTopLevelDecls(AST.getASTContext(), AST.getLocalTopLevelDecls(),
DeclMacrosFinder, IndexOpts);
return {DeclMacrosFinder.takeDecls(), DeclMacrosFinder.takeMacroInfos()};
}
llvm::Optional<Location>
makeLocation(ParsedAST &AST, const SourceRange &ValSourceRange) {
const SourceManager &SourceMgr = AST.getASTContext().getSourceManager();
const LangOptions &LangOpts = AST.getASTContext().getLangOpts();
SourceLocation LocStart = ValSourceRange.getBegin();
const FileEntry *F =
SourceMgr.getFileEntryForID(SourceMgr.getFileID(LocStart));
if (!F)
return llvm::None;
SourceLocation LocEnd = Lexer::getLocForEndOfToken(ValSourceRange.getEnd(), 0,
SourceMgr, LangOpts);
Position Begin = sourceLocToPosition(SourceMgr, LocStart);
Position End = sourceLocToPosition(SourceMgr, LocEnd);
Range R = {Begin, End};
Location L;
auto FilePath = getAbsoluteFilePath(F, SourceMgr);
if (!FilePath) {
log("failed to get path!");
return llvm::None;
}
L.uri = URIForFile(*FilePath);
L.range = R;
return L;
}
} // namespace
std::vector<Location> findDefinitions(ParsedAST &AST, Position Pos,
const SymbolIndex *Index) {
const SourceManager &SourceMgr = AST.getASTContext().getSourceManager();
std::vector<Location> Result;
// Handle goto definition for #include.
for (auto &Inc : AST.getIncludeStructure().MainFileIncludes) {
if (!Inc.Resolved.empty() && Inc.R.contains(Pos))
Result.push_back(Location{URIForFile{Inc.Resolved}, {}});
}
if (!Result.empty())
return Result;
// Identified symbols at a specific position.
SourceLocation SourceLocationBeg =
getBeginningOfIdentifier(AST, Pos, SourceMgr.getMainFileID());
auto Symbols = getSymbolAtPosition(AST, SourceLocationBeg);
for (auto Item : Symbols.Macros) {
auto Loc = Item.Info->getDefinitionLoc();
auto L = makeLocation(AST, SourceRange(Loc, Loc));
if (L)
Result.push_back(*L);
}
// Declaration and definition are different terms in C-family languages, and
// LSP only defines the "GoToDefinition" specification, so we try to perform
// the "most sensible" GoTo operation:
//
// - We use the location from AST and index (if available) to provide the
// final results. When there are duplicate results, we prefer AST over
// index because AST is more up-to-date.
//
// - For each symbol, we will return a location of the canonical declaration
// (e.g. function declaration in header), and a location of definition if
// they are available.
//
// So the work flow:
//
// 1. Identify the symbols being search for by traversing the AST.
// 2. Populate one of the locations with the AST location.
// 3. Use the AST information to query the index, and populate the index
// location (if available).
// 4. Return all populated locations for all symbols, definition first (
// which we think is the users wants most often).
struct CandidateLocation {
llvm::Optional<Location> Def;
llvm::Optional<Location> Decl;
};
llvm::DenseMap<SymbolID, CandidateLocation> ResultCandidates;
// Emit all symbol locations (declaration or definition) from AST.
for (const auto *D : Symbols.Decls) {
// Fake key for symbols don't have USR (no SymbolID).
// Ideally, there should be a USR for each identified symbols. Symbols
// without USR are rare and unimportant cases, we use the a fake holder to
// minimize the invasiveness of these cases.
SymbolID Key("");
if (auto ID = getSymbolID(D))
Key = *ID;
auto &Candidate = ResultCandidates[Key];
auto Loc = findNameLoc(D);
auto L = makeLocation(AST, SourceRange(Loc, Loc));
// The declaration in the identified symbols is a definition if possible
// otherwise it is declaration.
bool IsDef = getDefinition(D) == D;
// Populate one of the slots with location for the AST.
if (!IsDef)
Candidate.Decl = L;
else
Candidate.Def = L;
}
if (Index) {
LookupRequest QueryRequest;
// Build request for index query, using SymbolID.
for (auto It : ResultCandidates)
QueryRequest.IDs.insert(It.first);
std::string HintPath;
const FileEntry *FE =
SourceMgr.getFileEntryForID(SourceMgr.getMainFileID());
if (auto Path = getAbsoluteFilePath(FE, SourceMgr))
HintPath = *Path;
// Query the index and populate the empty slot.
Index->lookup(
QueryRequest, [&HintPath, &ResultCandidates](const Symbol &Sym) {
auto It = ResultCandidates.find(Sym.ID);
assert(It != ResultCandidates.end());
auto &Value = It->second;
if (!Value.Def)
Value.Def = toLSPLocation(Sym.Definition, HintPath);
if (!Value.Decl)
Value.Decl = toLSPLocation(Sym.CanonicalDeclaration, HintPath);
});
}
// Populate the results, definition first.
for (auto It : ResultCandidates) {
const auto &Candidate = It.second;
if (Candidate.Def)
Result.push_back(*Candidate.Def);
if (Candidate.Decl &&
Candidate.Decl != Candidate.Def) // Decl and Def might be the same
Result.push_back(*Candidate.Decl);
}
return Result;
}
namespace {
/// Finds document highlights that a given list of declarations refers to.
class DocumentHighlightsFinder : public index::IndexDataConsumer {
std::vector<const Decl *> &Decls;
std::vector<DocumentHighlight> DocumentHighlights;
const ASTContext &AST;
public:
DocumentHighlightsFinder(raw_ostream &OS, ASTContext &AST, Preprocessor &PP,
std::vector<const Decl *> &Decls)
: Decls(Decls), AST(AST) {}
std::vector<DocumentHighlight> takeHighlights() {
// Don't keep the same highlight multiple times.
// This can happen when nodes in the AST are visited twice.
std::sort(DocumentHighlights.begin(), DocumentHighlights.end());
auto Last =
std::unique(DocumentHighlights.begin(), DocumentHighlights.end());
DocumentHighlights.erase(Last, DocumentHighlights.end());
return std::move(DocumentHighlights);
}
bool
handleDeclOccurence(const Decl *D, index::SymbolRoleSet Roles,
ArrayRef<index::SymbolRelation> Relations,
SourceLocation Loc,
index::IndexDataConsumer::ASTNodeInfo ASTNode) override {
const SourceManager &SourceMgr = AST.getSourceManager();
SourceLocation HighlightStartLoc = SourceMgr.getFileLoc(Loc);
if (SourceMgr.getMainFileID() != SourceMgr.getFileID(HighlightStartLoc) ||
std::find(Decls.begin(), Decls.end(), D) == Decls.end()) {
return true;
}
SourceLocation End;
const LangOptions &LangOpts = AST.getLangOpts();
End = Lexer::getLocForEndOfToken(HighlightStartLoc, 0, SourceMgr, LangOpts);
SourceRange SR(HighlightStartLoc, End);
DocumentHighlightKind Kind = DocumentHighlightKind::Text;
if (static_cast<index::SymbolRoleSet>(index::SymbolRole::Write) & Roles)
Kind = DocumentHighlightKind::Write;
else if (static_cast<index::SymbolRoleSet>(index::SymbolRole::Read) & Roles)
Kind = DocumentHighlightKind::Read;
DocumentHighlights.push_back(getDocumentHighlight(SR, Kind));
return true;
}
private:
DocumentHighlight getDocumentHighlight(SourceRange SR,
DocumentHighlightKind Kind) {
const SourceManager &SourceMgr = AST.getSourceManager();
Position Begin = sourceLocToPosition(SourceMgr, SR.getBegin());
Position End = sourceLocToPosition(SourceMgr, SR.getEnd());
Range R = {Begin, End};
DocumentHighlight DH;
DH.range = R;
DH.kind = Kind;
return DH;
}
};
} // namespace
std::vector<DocumentHighlight> findDocumentHighlights(ParsedAST &AST,
Position Pos) {
const SourceManager &SourceMgr = AST.getASTContext().getSourceManager();
[clangd] Fix unicode handling, using UTF-16 where LSP requires it. Summary: The Language Server Protocol unfortunately mandates that locations in files be represented by line/column pairs, where the "column" is actually an index into the UTF-16-encoded text of the line. (This is because VSCode is written in JavaScript, which is UTF-16-native). Internally clangd treats source files at UTF-8, the One True Encoding, and generally deals with byte offsets (though there are exceptions). Before this patch, conversions between offsets and LSP Position pretended that Position.character was UTF-8 bytes, which is only true for ASCII lines. Now we examine the text to convert correctly (but don't actually need to transcode it, due to some nice details of the encodings). The updated functions in SourceCode are the blessed way to interact with the Position.character field, and anything else is likely to be wrong. So I also updated the other accesses: - CodeComplete needs a "clang-style" line/column, with column in utf-8 bytes. This is now converted via Position -> offset -> clang line/column (a new function is added to SourceCode.h for the second conversion). - getBeginningOfIdentifier skipped backwards in UTF-16 space, which is will behave badly when it splits a surrogate pair. Skipping backwards in UTF-8 coordinates gives the lexer a fighting chance of getting this right. While here, I clarified(?) the logic comments, fixed a bug with identifiers containing digits, simplified the signature slightly and added a test. This seems likely to cause problems with editors that have the same bug, and treat the protocol as if columns are UTF-8 bytes. But we can find and fix those. Reviewers: hokein Subscribers: klimek, ilya-biryukov, ioeric, MaskRay, jkorous, cfe-commits Differential Revision: https://reviews.llvm.org/D46035 llvm-svn: 331029
2018-04-27 19:59:28 +08:00
SourceLocation SourceLocationBeg =
getBeginningOfIdentifier(AST, Pos, SourceMgr.getMainFileID());
auto Symbols = getSymbolAtPosition(AST, SourceLocationBeg);
std::vector<const Decl *> SelectedDecls = Symbols.Decls;
DocumentHighlightsFinder DocHighlightsFinder(
llvm::errs(), AST.getASTContext(), AST.getPreprocessor(), SelectedDecls);
index::IndexingOptions IndexOpts;
IndexOpts.SystemSymbolFilter =
index::IndexingOptions::SystemSymbolFilterKind::All;
IndexOpts.IndexFunctionLocals = true;
indexTopLevelDecls(AST.getASTContext(), AST.getLocalTopLevelDecls(),
DocHighlightsFinder, IndexOpts);
return DocHighlightsFinder.takeHighlights();
}
static PrintingPolicy printingPolicyForDecls(PrintingPolicy Base) {
PrintingPolicy Policy(Base);
Policy.AnonymousTagLocations = false;
Policy.TerseOutput = true;
Policy.PolishForDeclaration = true;
Policy.ConstantsAsWritten = true;
Policy.SuppressTagKeyword = false;
return Policy;
}
/// Return a string representation (e.g. "class MyNamespace::MyClass") of
/// the type declaration \p TD.
static std::string typeDeclToString(const TypeDecl *TD) {
QualType Type = TD->getASTContext().getTypeDeclType(TD);
PrintingPolicy Policy =
printingPolicyForDecls(TD->getASTContext().getPrintingPolicy());
std::string Name;
llvm::raw_string_ostream Stream(Name);
Type.print(Stream, Policy);
return Stream.str();
}
/// Return a string representation (e.g. "namespace ns1::ns2") of
/// the named declaration \p ND.
static std::string namedDeclQualifiedName(const NamedDecl *ND,
StringRef Prefix) {
PrintingPolicy Policy =
printingPolicyForDecls(ND->getASTContext().getPrintingPolicy());
std::string Name;
llvm::raw_string_ostream Stream(Name);
Stream << Prefix << ' ';
ND->printQualifiedName(Stream, Policy);
return Stream.str();
}
/// Given a declaration \p D, return a human-readable string representing the
/// scope in which it is declared. If the declaration is in the global scope,
/// return the string "global namespace".
static llvm::Optional<std::string> getScopeName(const Decl *D) {
const DeclContext *DC = D->getDeclContext();
if (isa<TranslationUnitDecl>(DC))
return std::string("global namespace");
if (const TypeDecl *TD = dyn_cast<TypeDecl>(DC))
return typeDeclToString(TD);
else if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC))
return namedDeclQualifiedName(ND, "namespace");
else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
return namedDeclQualifiedName(FD, "function");
return llvm::None;
}
/// Generate a \p Hover object given the declaration \p D.
static Hover getHoverContents(const Decl *D) {
Hover H;
llvm::Optional<std::string> NamedScope = getScopeName(D);
// Generate the "Declared in" section.
if (NamedScope) {
assert(!NamedScope->empty());
H.contents.value += "Declared in ";
H.contents.value += *NamedScope;
H.contents.value += "\n\n";
}
// We want to include the template in the Hover.
if (TemplateDecl *TD = D->getDescribedTemplate())
D = TD;
std::string DeclText;
llvm::raw_string_ostream OS(DeclText);
PrintingPolicy Policy =
printingPolicyForDecls(D->getASTContext().getPrintingPolicy());
D->print(OS, Policy);
OS.flush();
H.contents.value += DeclText;
return H;
}
/// Generate a \p Hover object given the type \p T.
static Hover getHoverContents(QualType T, ASTContext &ASTCtx) {
Hover H;
std::string TypeText;
llvm::raw_string_ostream OS(TypeText);
PrintingPolicy Policy = printingPolicyForDecls(ASTCtx.getPrintingPolicy());
T.print(OS, Policy);
OS.flush();
H.contents.value += TypeText;
return H;
}
/// Generate a \p Hover object given the macro \p MacroInf.
static Hover getHoverContents(StringRef MacroName) {
Hover H;
H.contents.value = "#define ";
H.contents.value += MacroName;
return H;
}
namespace {
/// Computes the deduced type at a given location by visiting the relevant
/// nodes. We use this to display the actual type when hovering over an "auto"
/// keyword or "decltype()" expression.
/// FIXME: This could have been a lot simpler by visiting AutoTypeLocs but it
/// seems that the AutoTypeLocs that can be visited along with their AutoType do
/// not have the deduced type set. Instead, we have to go to the appropriate
/// DeclaratorDecl/FunctionDecl and work our back to the AutoType that does have
/// a deduced type set. The AST should be improved to simplify this scenario.
class DeducedTypeVisitor : public RecursiveASTVisitor<DeducedTypeVisitor> {
SourceLocation SearchedLocation;
llvm::Optional<QualType> DeducedType;
public:
DeducedTypeVisitor(SourceLocation SearchedLocation)
: SearchedLocation(SearchedLocation) {}
llvm::Optional<QualType> getDeducedType() { return DeducedType; }
// Handle auto initializers:
//- auto i = 1;
//- decltype(auto) i = 1;
//- auto& i = 1;
bool VisitDeclaratorDecl(DeclaratorDecl *D) {
if (!D->getTypeSourceInfo() ||
D->getTypeSourceInfo()->getTypeLoc().getBeginLoc() != SearchedLocation)
return true;
auto DeclT = D->getType();
// "auto &" is represented as a ReferenceType containing an AutoType
if (const ReferenceType *RT = dyn_cast<ReferenceType>(DeclT.getTypePtr()))
DeclT = RT->getPointeeType();
const AutoType *AT = dyn_cast<AutoType>(DeclT.getTypePtr());
if (AT && !AT->getDeducedType().isNull()) {
// For auto, use the underlying type because the const& would be
// represented twice: written in the code and in the hover.
// Example: "const auto I = 1", we only want "int" when hovering on auto,
// not "const int".
//
// For decltype(auto), take the type as is because it cannot be written
// with qualifiers or references but its decuded type can be const-ref.
DeducedType = AT->isDecltypeAuto() ? DeclT : DeclT.getUnqualifiedType();
}
return true;
}
// Handle auto return types:
//- auto foo() {}
//- auto& foo() {}
//- auto foo() -> decltype(1+1) {}
//- operator auto() const { return 10; }
bool VisitFunctionDecl(FunctionDecl *D) {
if (!D->getTypeSourceInfo())
return true;
// Loc of auto in return type (c++14).
auto CurLoc = D->getReturnTypeSourceRange().getBegin();
// Loc of "auto" in operator auto()
if (CurLoc.isInvalid() && dyn_cast<CXXConversionDecl>(D))
CurLoc = D->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
// Loc of "auto" in function with traling return type (c++11).
if (CurLoc.isInvalid())
CurLoc = D->getSourceRange().getBegin();
if (CurLoc != SearchedLocation)
return true;
auto T = D->getReturnType();
// "auto &" is represented as a ReferenceType containing an AutoType.
if (const ReferenceType *RT = dyn_cast<ReferenceType>(T.getTypePtr()))
T = RT->getPointeeType();
const AutoType *AT = dyn_cast<AutoType>(T.getTypePtr());
if (AT && !AT->getDeducedType().isNull()) {
DeducedType = T.getUnqualifiedType();
} else { // auto in a trailing return type just points to a DecltypeType.
const DecltypeType *DT = dyn_cast<DecltypeType>(T.getTypePtr());
if (!DT->getUnderlyingType().isNull())
DeducedType = DT->getUnderlyingType();
}
return true;
}
// Handle non-auto decltype, e.g.:
// - auto foo() -> decltype(expr) {}
// - decltype(expr);
bool VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
if (TL.getBeginLoc() != SearchedLocation)
return true;
// A DecltypeType's underlying type can be another DecltypeType! E.g.
// int I = 0;
// decltype(I) J = I;
// decltype(J) K = J;
const DecltypeType *DT = dyn_cast<DecltypeType>(TL.getTypePtr());
while (DT && !DT->getUnderlyingType().isNull()) {
DeducedType = DT->getUnderlyingType();
DT = dyn_cast<DecltypeType>(DeducedType->getTypePtr());
}
return true;
}
};
} // namespace
/// Retrieves the deduced type at a given location (auto, decltype).
llvm::Optional<QualType> getDeducedType(ParsedAST &AST,
SourceLocation SourceLocationBeg) {
Token Tok;
auto &ASTCtx = AST.getASTContext();
// Only try to find a deduced type if the token is auto or decltype.
if (!SourceLocationBeg.isValid() ||
Lexer::getRawToken(SourceLocationBeg, Tok, ASTCtx.getSourceManager(),
ASTCtx.getLangOpts(), false) ||
!Tok.is(tok::raw_identifier)) {
return {};
}
AST.getPreprocessor().LookUpIdentifierInfo(Tok);
if (!(Tok.is(tok::kw_auto) || Tok.is(tok::kw_decltype)))
return {};
DeducedTypeVisitor V(SourceLocationBeg);
for (Decl *D : AST.getLocalTopLevelDecls())
V.TraverseDecl(D);
return V.getDeducedType();
}
Optional<Hover> getHover(ParsedAST &AST, Position Pos) {
const SourceManager &SourceMgr = AST.getASTContext().getSourceManager();
[clangd] Fix unicode handling, using UTF-16 where LSP requires it. Summary: The Language Server Protocol unfortunately mandates that locations in files be represented by line/column pairs, where the "column" is actually an index into the UTF-16-encoded text of the line. (This is because VSCode is written in JavaScript, which is UTF-16-native). Internally clangd treats source files at UTF-8, the One True Encoding, and generally deals with byte offsets (though there are exceptions). Before this patch, conversions between offsets and LSP Position pretended that Position.character was UTF-8 bytes, which is only true for ASCII lines. Now we examine the text to convert correctly (but don't actually need to transcode it, due to some nice details of the encodings). The updated functions in SourceCode are the blessed way to interact with the Position.character field, and anything else is likely to be wrong. So I also updated the other accesses: - CodeComplete needs a "clang-style" line/column, with column in utf-8 bytes. This is now converted via Position -> offset -> clang line/column (a new function is added to SourceCode.h for the second conversion). - getBeginningOfIdentifier skipped backwards in UTF-16 space, which is will behave badly when it splits a surrogate pair. Skipping backwards in UTF-8 coordinates gives the lexer a fighting chance of getting this right. While here, I clarified(?) the logic comments, fixed a bug with identifiers containing digits, simplified the signature slightly and added a test. This seems likely to cause problems with editors that have the same bug, and treat the protocol as if columns are UTF-8 bytes. But we can find and fix those. Reviewers: hokein Subscribers: klimek, ilya-biryukov, ioeric, MaskRay, jkorous, cfe-commits Differential Revision: https://reviews.llvm.org/D46035 llvm-svn: 331029
2018-04-27 19:59:28 +08:00
SourceLocation SourceLocationBeg =
getBeginningOfIdentifier(AST, Pos, SourceMgr.getMainFileID());
// Identified symbols at a specific position.
auto Symbols = getSymbolAtPosition(AST, SourceLocationBeg);
if (!Symbols.Macros.empty())
return getHoverContents(Symbols.Macros[0].Name);
if (!Symbols.Decls.empty())
return getHoverContents(Symbols.Decls[0]);
auto DeducedType = getDeducedType(AST, SourceLocationBeg);
if (DeducedType && !DeducedType->isNull())
return getHoverContents(*DeducedType, AST.getASTContext());
return None;
}
} // namespace clangd
} // namespace clang