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

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//===--- XRefs.cpp -----------------------------------------------*- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "XRefs.h"
#include "AST.h"
#include "CodeCompletionStrings.h"
#include "FindSymbols.h"
#include "FindTarget.h"
#include "ParsedAST.h"
#include "Protocol.h"
#include "Quality.h"
#include "Selection.h"
#include "SourceCode.h"
#include "URI.h"
#include "index/Index.h"
#include "index/Merge.h"
#include "index/Relation.h"
#include "index/SymbolLocation.h"
#include "support/Logger.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTTypeTraits.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Attrs.inc"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/Type.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Index/IndexDataConsumer.h"
#include "clang/Index/IndexSymbol.h"
#include "clang/Index/IndexingAction.h"
#include "clang/Index/IndexingOptions.h"
#include "clang/Index/USRGeneration.h"
#include "clang/Tooling/Syntax/Tokens.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
namespace clang {
namespace clangd {
namespace {
// Returns the single definition of the entity declared by D, if visible.
// In particular:
// - for non-redeclarable kinds (e.g. local vars), return D
// - for kinds that allow multiple definitions (e.g. namespaces), return nullptr
// Kinds of nodes that always return nullptr here will not have definitions
// reported by locateSymbolAt().
const NamedDecl *getDefinition(const NamedDecl *D) {
assert(D);
// Decl has one definition that we can find.
if (const auto *TD = dyn_cast<TagDecl>(D))
return TD->getDefinition();
if (const auto *VD = dyn_cast<VarDecl>(D))
return VD->getDefinition();
if (const auto *FD = dyn_cast<FunctionDecl>(D))
return FD->getDefinition();
// Objective-C classes can have three types of declarations:
//
// - forward declaration: @class MyClass;
// - true declaration (interface definition): @interface MyClass ... @end
// - true definition (implementation): @implementation MyClass ... @end
//
// Objective-C categories are extensions are on classes:
//
// - declaration: @interface MyClass (Ext) ... @end
// - definition: @implementation MyClass (Ext) ... @end
//
// With one special case, a class extension, which is normally used to keep
// some declarations internal to a file without exposing them in a header.
//
// - class extension declaration: @interface MyClass () ... @end
// - which really links to class definition: @implementation MyClass ... @end
if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(D))
return ID->getImplementation();
if (const auto *CD = dyn_cast<ObjCCategoryDecl>(D)) {
if (CD->IsClassExtension()) {
if (const auto *ID = CD->getClassInterface())
return ID->getImplementation();
return nullptr;
}
return CD->getImplementation();
}
// Only a single declaration is allowed.
if (isa<ValueDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
isa<TemplateTemplateParmDecl>(D)) // except cases above
return D;
// Multiple definitions are allowed.
return nullptr; // except cases above
}
void logIfOverflow(const SymbolLocation &Loc) {
if (Loc.Start.hasOverflow() || Loc.End.hasOverflow())
log("Possible overflow in symbol location: {0}", Loc);
}
// Convert a SymbolLocation to LSP's Location.
// TUPath 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 TUPath) {
if (!Loc)
return None;
auto Uri = URI::parse(Loc.FileURI);
if (!Uri) {
elog("Could not parse URI {0}: {1}", Loc.FileURI, Uri.takeError());
return None;
}
auto U = URIForFile::fromURI(*Uri, TUPath);
if (!U) {
elog("Could not resolve URI {0}: {1}", Loc.FileURI, U.takeError());
return None;
}
Location LSPLoc;
LSPLoc.uri = std::move(*U);
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();
logIfOverflow(Loc);
return LSPLoc;
}
SymbolLocation toIndexLocation(const Location &Loc, std::string &URIStorage) {
SymbolLocation SymLoc;
URIStorage = Loc.uri.uri();
SymLoc.FileURI = URIStorage.c_str();
SymLoc.Start.setLine(Loc.range.start.line);
SymLoc.Start.setColumn(Loc.range.start.character);
SymLoc.End.setLine(Loc.range.end.line);
SymLoc.End.setColumn(Loc.range.end.character);
return SymLoc;
}
// Returns the preferred location between an AST location and an index location.
SymbolLocation getPreferredLocation(const Location &ASTLoc,
const SymbolLocation &IdxLoc,
std::string &Scratch) {
// Also use a dummy symbol for the index location so that other fields (e.g.
// definition) are not factored into the preference.
Symbol ASTSym, IdxSym;
ASTSym.ID = IdxSym.ID = SymbolID("dummy_id");
ASTSym.CanonicalDeclaration = toIndexLocation(ASTLoc, Scratch);
IdxSym.CanonicalDeclaration = IdxLoc;
auto Merged = mergeSymbol(ASTSym, IdxSym);
return Merged.CanonicalDeclaration;
}
std::vector<std::pair<const NamedDecl *, DeclRelationSet>>
getDeclAtPositionWithRelations(ParsedAST &AST, SourceLocation Pos,
DeclRelationSet Relations,
ASTNodeKind *NodeKind = nullptr) {
unsigned Offset = AST.getSourceManager().getDecomposedSpellingLoc(Pos).second;
std::vector<std::pair<const NamedDecl *, DeclRelationSet>> Result;
auto ResultFromTree = [&](SelectionTree ST) {
if (const SelectionTree::Node *N = ST.commonAncestor()) {
if (NodeKind)
*NodeKind = N->ASTNode.getNodeKind();
llvm::copy_if(allTargetDecls(N->ASTNode), std::back_inserter(Result),
[&](auto &Entry) { return !(Entry.second & ~Relations); });
}
return !Result.empty();
};
SelectionTree::createEach(AST.getASTContext(), AST.getTokens(), Offset,
Offset, ResultFromTree);
return Result;
}
std::vector<const NamedDecl *>
getDeclAtPosition(ParsedAST &AST, SourceLocation Pos, DeclRelationSet Relations,
ASTNodeKind *NodeKind = nullptr) {
std::vector<const NamedDecl *> Result;
for (auto &Entry :
getDeclAtPositionWithRelations(AST, Pos, Relations, NodeKind))
Result.push_back(Entry.first);
return Result;
}
// Expects Loc to be a SpellingLocation, will bail out otherwise as it can't
// figure out a filename.
llvm::Optional<Location> makeLocation(const ASTContext &AST, SourceLocation Loc,
llvm::StringRef TUPath) {
const auto &SM = AST.getSourceManager();
const FileEntry *F = SM.getFileEntryForID(SM.getFileID(Loc));
if (!F)
return None;
auto FilePath = getCanonicalPath(F, SM);
if (!FilePath) {
log("failed to get path!");
return None;
}
Location L;
L.uri = URIForFile::canonicalize(*FilePath, TUPath);
// We call MeasureTokenLength here as TokenBuffer doesn't store spelled tokens
// outside the main file.
auto TokLen = Lexer::MeasureTokenLength(Loc, SM, AST.getLangOpts());
L.range = halfOpenToRange(
SM, CharSourceRange::getCharRange(Loc, Loc.getLocWithOffset(TokLen)));
return L;
}
// Treat #included files as symbols, to enable go-to-definition on them.
llvm::Optional<LocatedSymbol> locateFileReferent(const Position &Pos,
ParsedAST &AST,
llvm::StringRef MainFilePath) {
for (auto &Inc : AST.getIncludeStructure().MainFileIncludes) {
if (!Inc.Resolved.empty() && Inc.HashLine == Pos.line) {
LocatedSymbol File;
File.Name = std::string(llvm::sys::path::filename(Inc.Resolved));
File.PreferredDeclaration = {
URIForFile::canonicalize(Inc.Resolved, MainFilePath), Range{}};
File.Definition = File.PreferredDeclaration;
// We're not going to find any further symbols on #include lines.
return File;
}
}
return llvm::None;
}
// Macros are simple: there's no declaration/definition distinction.
// As a consequence, there's no need to look them up in the index either.
llvm::Optional<LocatedSymbol>
locateMacroReferent(const syntax::Token &TouchedIdentifier, ParsedAST &AST,
llvm::StringRef MainFilePath) {
if (auto M = locateMacroAt(TouchedIdentifier, AST.getPreprocessor())) {
[clangd] locateMacroAt handles patched macros Summary: Depends on D79992. This patch changes locateMacroAt to perform #line directive substitution for macro identifier locations. We first check whether a location is inside a file included through built-in header. If so we check whether line directive maps it back to the main file, and afterwards use TokenBuffers to find exact location of the identifier on the line. Instead of performing the mapping in locateMacroAt, we could also store a mapping inside the ParsedAST whenever we use a patched preamble. But that would imply adding more responsibility to ParsedAST and paying for the mapping even when it is not going to be used. ==== Go-To-Definition: Later on these locations are used for serving go-to-definition requests, this enables jumping to definition inside the preamble section in presence of patched macros. ===== Go-To-Refs: Macro references in main file are collected separetely and stored as a map from macro's symbol id to reference ranges. Those ranges are computed inside PPCallbacks, hence we don't have access to TokenBuffer. In presence of preamble patch, any reference to a macro inside the preamble section will unfortunately have the wrong range. They'll point into the patch rather than the main file. Hence during findReferences, we won't get any ranges reported for those. Fixing those requires: - Lexing the preamble section to figure out "real range" of a patched macro definition - Postponing range/location calculations until a later step in which we have access to tokenbuffers. This patch trades some accuracy in favor of code complexity. We don't do any patching for references inside the preamble patch but get any reference inside the main file for free. Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, usaxena95, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D80198
2020-05-14 18:26:47 +08:00
if (auto Loc =
makeLocation(AST.getASTContext(), M->NameLoc, MainFilePath)) {
LocatedSymbol Macro;
Macro.Name = std::string(M->Name);
Macro.PreferredDeclaration = *Loc;
Macro.Definition = Loc;
return Macro;
}
}
return llvm::None;
}
// A wrapper around `Decl::getCanonicalDecl` to support cases where Clang's
// definition of a canonical declaration doesn't match up to what a programmer
// would expect. For example, Objective-C classes can have three types of
// declarations:
//
// - forward declaration(s): @class MyClass;
// - true declaration (interface definition): @interface MyClass ... @end
// - true definition (implementation): @implementation MyClass ... @end
//
// Clang will consider the forward declaration to be the canonical declaration
// because it is first. We actually want the class definition if it is
// available since that is what a programmer would consider the primary
// declaration to be.
const NamedDecl *getPreferredDecl(const NamedDecl *D) {
// FIXME: Canonical declarations of some symbols might refer to built-in
// decls with possibly-invalid source locations (e.g. global new operator).
// In such cases we should pick up a redecl with valid source location
// instead of failing.
D = llvm::cast<NamedDecl>(D->getCanonicalDecl());
// Prefer Objective-C class/protocol definitions over the forward declaration.
if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(D))
if (const auto *DefinitionID = ID->getDefinition())
return DefinitionID;
if (const auto *PD = dyn_cast<ObjCProtocolDecl>(D))
if (const auto *DefinitionID = PD->getDefinition())
return DefinitionID;
return D;
}
std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs,
RelationKind Predicate,
const SymbolIndex *Index,
llvm::StringRef MainFilePath) {
if (IDs.empty())
return {};
static constexpr trace::Metric FindImplementorsMetric(
"find_implementors", trace::Metric::Counter, "case");
switch (Predicate) {
case RelationKind::BaseOf:
FindImplementorsMetric.record(1, "find-base");
break;
case RelationKind::OverriddenBy:
FindImplementorsMetric.record(1, "find-override");
break;
}
RelationsRequest Req;
Req.Predicate = Predicate;
Req.Subjects = std::move(IDs);
std::vector<LocatedSymbol> Results;
Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) {
auto DeclLoc =
indexToLSPLocation(Object.CanonicalDeclaration, MainFilePath);
if (!DeclLoc) {
elog("Find overrides: {0}", DeclLoc.takeError());
return;
}
Results.emplace_back();
Results.back().Name = Object.Name.str();
Results.back().PreferredDeclaration = *DeclLoc;
auto DefLoc = indexToLSPLocation(Object.Definition, MainFilePath);
if (!DefLoc) {
elog("Failed to convert location: {0}", DefLoc.takeError());
return;
}
Results.back().Definition = *DefLoc;
});
return Results;
}
// Decls are more complicated.
// The AST contains at least a declaration, maybe a definition.
// These are up-to-date, and so generally preferred over index results.
// We perform a single batch index lookup to find additional definitions.
std::vector<LocatedSymbol>
locateASTReferent(SourceLocation CurLoc, const syntax::Token *TouchedIdentifier,
ParsedAST &AST, llvm::StringRef MainFilePath,
const SymbolIndex *Index, ASTNodeKind *NodeKind) {
const SourceManager &SM = AST.getSourceManager();
// Results follow the order of Symbols.Decls.
std::vector<LocatedSymbol> Result;
// Keep track of SymbolID -> index mapping, to fill in index data later.
llvm::DenseMap<SymbolID, size_t> ResultIndex;
static constexpr trace::Metric LocateASTReferentMetric(
"locate_ast_referent", trace::Metric::Counter, "case");
auto AddResultDecl = [&](const NamedDecl *D) {
D = getPreferredDecl(D);
auto Loc =
makeLocation(AST.getASTContext(), nameLocation(*D, SM), MainFilePath);
if (!Loc)
return;
Result.emplace_back();
Result.back().Name = printName(AST.getASTContext(), *D);
Result.back().PreferredDeclaration = *Loc;
if (const NamedDecl *Def = getDefinition(D))
Result.back().Definition = makeLocation(
AST.getASTContext(), nameLocation(*Def, SM), MainFilePath);
// Record SymbolID for index lookup later.
if (auto ID = getSymbolID(D))
ResultIndex[ID] = Result.size() - 1;
};
// Emit all symbol locations (declaration or definition) from AST.
DeclRelationSet Relations =
DeclRelation::TemplatePattern | DeclRelation::Alias;
auto Candidates =
getDeclAtPositionWithRelations(AST, CurLoc, Relations, NodeKind);
llvm::DenseSet<SymbolID> VirtualMethods;
for (const auto &E : Candidates) {
const NamedDecl *D = E.first;
if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(D)) {
// Special case: virtual void ^method() = 0: jump to all overrides.
// FIXME: extend it to ^virtual, unfortunately, virtual location is not
// saved in the AST.
if (CMD->isPure()) {
if (TouchedIdentifier && SM.getSpellingLoc(CMD->getLocation()) ==
TouchedIdentifier->location()) {
VirtualMethods.insert(getSymbolID(CMD));
LocateASTReferentMetric.record(1, "method-to-override");
}
}
// Special case: void foo() ^override: jump to the overridden method.
const InheritableAttr *Attr = D->getAttr<OverrideAttr>();
if (!Attr)
Attr = D->getAttr<FinalAttr>();
if (Attr && TouchedIdentifier &&
SM.getSpellingLoc(Attr->getLocation()) ==
TouchedIdentifier->location()) {
LocateASTReferentMetric.record(1, "method-to-base");
// We may be overridding multiple methods - offer them all.
for (const NamedDecl *ND : CMD->overridden_methods())
AddResultDecl(ND);
continue;
}
}
// Special case: the cursor is on an alias, prefer other results.
// This targets "using ns::^Foo", where the target is more interesting.
// This does not trigger on renaming aliases:
// `using Foo = ^Bar` already targets Bar via a TypeLoc
// `using ^Foo = Bar` has no other results, as Underlying is filtered.
if (E.second & DeclRelation::Alias && Candidates.size() > 1 &&
// beginLoc/endLoc are a token range, so rewind the identifier we're in.
SM.isPointWithin(TouchedIdentifier ? TouchedIdentifier->location()
: CurLoc,
D->getBeginLoc(), D->getEndLoc()))
continue;
// Special case: the point of declaration of a template specialization,
// it's more useful to navigate to the template declaration.
if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
if (TouchedIdentifier &&
D->getLocation() == TouchedIdentifier->location()) {
LocateASTReferentMetric.record(1, "template-specialization-to-primary");
AddResultDecl(CTSD->getSpecializedTemplate());
continue;
}
}
// Special case: if the class name is selected, also map Objective-C
// categories and category implementations back to their class interface.
//
// Since `TouchedIdentifier` might refer to the `ObjCCategoryImplDecl`
// instead of the `ObjCCategoryDecl` we intentionally check the contents
// of the locs when checking for class name equivalence.
if (const auto *CD = dyn_cast<ObjCCategoryDecl>(D))
if (const auto *ID = CD->getClassInterface())
if (TouchedIdentifier &&
(CD->getLocation() == TouchedIdentifier->location() ||
ID->getName() == TouchedIdentifier->text(SM))) {
LocateASTReferentMetric.record(1, "objc-category-to-class");
AddResultDecl(ID);
}
LocateASTReferentMetric.record(1, "regular");
// Otherwise the target declaration is the right one.
AddResultDecl(D);
}
// Now query the index for all Symbol IDs we found in the AST.
if (Index && !ResultIndex.empty()) {
LookupRequest QueryRequest;
for (auto It : ResultIndex)
QueryRequest.IDs.insert(It.first);
std::string Scratch;
Index->lookup(QueryRequest, [&](const Symbol &Sym) {
auto &R = Result[ResultIndex.lookup(Sym.ID)];
if (R.Definition) { // from AST
// Special case: if the AST yielded a definition, then it may not be
// the right *declaration*. Prefer the one from the index.
if (auto Loc = toLSPLocation(Sym.CanonicalDeclaration, MainFilePath))
R.PreferredDeclaration = *Loc;
// We might still prefer the definition from the index, e.g. for
// generated symbols.
if (auto Loc = toLSPLocation(
getPreferredLocation(*R.Definition, Sym.Definition, Scratch),
MainFilePath))
R.Definition = *Loc;
} else {
R.Definition = toLSPLocation(Sym.Definition, MainFilePath);
// Use merge logic to choose AST or index declaration.
if (auto Loc = toLSPLocation(
getPreferredLocation(R.PreferredDeclaration,
Sym.CanonicalDeclaration, Scratch),
MainFilePath))
R.PreferredDeclaration = *Loc;
}
});
}
auto Overrides = findImplementors(VirtualMethods, RelationKind::OverriddenBy,
Index, MainFilePath);
Result.insert(Result.end(), Overrides.begin(), Overrides.end());
return Result;
}
std::vector<LocatedSymbol> locateSymbolForType(const ParsedAST &AST,
const QualType &Type) {
const auto &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 symbol.");
return {};
}
auto Decls = targetDecl(DynTypedNode::create(Type.getNonReferenceType()),
DeclRelation::TemplatePattern | DeclRelation::Alias);
if (Decls.empty())
return {};
std::vector<LocatedSymbol> Results;
const auto &ASTContext = AST.getASTContext();
for (const NamedDecl *D : Decls) {
D = getPreferredDecl(D);
auto Loc = makeLocation(ASTContext, nameLocation(*D, SM), *MainFilePath);
if (!Loc)
continue;
Results.emplace_back();
Results.back().Name = printName(ASTContext, *D);
Results.back().PreferredDeclaration = *Loc;
if (const NamedDecl *Def = getDefinition(D))
Results.back().Definition =
makeLocation(ASTContext, nameLocation(*Def, SM), *MainFilePath);
}
return Results;
}
bool tokenSpelledAt(SourceLocation SpellingLoc, const syntax::TokenBuffer &TB) {
auto ExpandedTokens = TB.expandedTokens(
TB.sourceManager().getMacroArgExpandedLocation(SpellingLoc));
return !ExpandedTokens.empty();
}
llvm::StringRef sourcePrefix(SourceLocation Loc, const SourceManager &SM) {
auto D = SM.getDecomposedLoc(Loc);
bool Invalid = false;
llvm::StringRef Buf = SM.getBufferData(D.first, &Invalid);
if (Invalid || D.second > Buf.size())
return "";
return Buf.substr(0, D.second);
}
bool isDependentName(ASTNodeKind NodeKind) {
return NodeKind.isSame(ASTNodeKind::getFromNodeKind<OverloadExpr>()) ||
NodeKind.isSame(
ASTNodeKind::getFromNodeKind<CXXDependentScopeMemberExpr>()) ||
NodeKind.isSame(
ASTNodeKind::getFromNodeKind<DependentScopeDeclRefExpr>());
}
} // namespace
std::vector<LocatedSymbol>
locateSymbolTextually(const SpelledWord &Word, ParsedAST &AST,
const SymbolIndex *Index, const std::string &MainFilePath,
ASTNodeKind NodeKind) {
// Don't use heuristics if this is a real identifier, or not an
// identifier.
// Exception: dependent names, because those may have useful textual
// matches that AST-based heuristics cannot find.
if ((Word.ExpandedToken && !isDependentName(NodeKind)) ||
!Word.LikelyIdentifier || !Index)
return {};
2020-09-24 16:49:32 +08:00
// We don't want to handle words in string literals. (It'd be nice to list
// *allowed* token kinds explicitly, but comment Tokens aren't retained).
if (Word.PartOfSpelledToken &&
isStringLiteral(Word.PartOfSpelledToken->kind()))
return {};
const auto &SM = AST.getSourceManager();
// Look up the selected word in the index.
FuzzyFindRequest Req;
Req.Query = Word.Text.str();
Req.ProximityPaths = {MainFilePath};
// Find the namespaces to query by lexing the file.
Req.Scopes =
visibleNamespaces(sourcePrefix(Word.Location, SM), AST.getLangOpts());
// FIXME: For extra strictness, consider AnyScope=false.
Req.AnyScope = true;
// We limit the results to 3 further below. This limit is to avoid fetching
// too much data, while still likely having enough for 3 results to remain
// after additional filtering.
Req.Limit = 10;
bool TooMany = false;
using ScoredLocatedSymbol = std::pair<float, LocatedSymbol>;
std::vector<ScoredLocatedSymbol> ScoredResults;
Index->fuzzyFind(Req, [&](const Symbol &Sym) {
// Only consider exact name matches, including case.
// This is to avoid too many false positives.
// We could relax this in the future (e.g. to allow for typos) if we make
// the query more accurate by other means.
if (Sym.Name != Word.Text)
return;
// Exclude constructor results. They have the same name as the class,
// but we don't have enough context to prefer them over the class.
if (Sym.SymInfo.Kind == index::SymbolKind::Constructor)
return;
auto MaybeDeclLoc =
indexToLSPLocation(Sym.CanonicalDeclaration, MainFilePath);
if (!MaybeDeclLoc) {
log("locateSymbolNamedTextuallyAt: {0}", MaybeDeclLoc.takeError());
return;
}
LocatedSymbol Located;
Located.PreferredDeclaration = *MaybeDeclLoc;
Located.Name = (Sym.Name + Sym.TemplateSpecializationArgs).str();
if (Sym.Definition) {
auto MaybeDefLoc = indexToLSPLocation(Sym.Definition, MainFilePath);
if (!MaybeDefLoc) {
log("locateSymbolNamedTextuallyAt: {0}", MaybeDefLoc.takeError());
return;
}
Located.PreferredDeclaration = *MaybeDefLoc;
Located.Definition = *MaybeDefLoc;
}
if (ScoredResults.size() >= 5) {
// If we have more than 5 results, don't return anything,
// as confidence is too low.
// FIXME: Alternatively, try a stricter query?
TooMany = true;
return;
}
SymbolQualitySignals Quality;
Quality.merge(Sym);
SymbolRelevanceSignals Relevance;
Relevance.Name = Sym.Name;
Relevance.Query = SymbolRelevanceSignals::Generic;
Relevance.merge(Sym);
auto Score = evaluateSymbolAndRelevance(Quality.evaluateHeuristics(),
Relevance.evaluateHeuristics());
dlog("locateSymbolNamedTextuallyAt: {0}{1} = {2}\n{3}{4}\n", Sym.Scope,
Sym.Name, Score, Quality, Relevance);
ScoredResults.push_back({Score, std::move(Located)});
});
if (TooMany) {
vlog("Heuristic index lookup for {0} returned too many candidates, ignored",
Word.Text);
return {};
}
llvm::sort(ScoredResults,
[](const ScoredLocatedSymbol &A, const ScoredLocatedSymbol &B) {
return A.first > B.first;
});
std::vector<LocatedSymbol> Results;
for (auto &Res : std::move(ScoredResults))
Results.push_back(std::move(Res.second));
if (Results.empty())
vlog("No heuristic index definition for {0}", Word.Text);
else
log("Found definition heuristically in index for {0}", Word.Text);
return Results;
}
const syntax::Token *findNearbyIdentifier(const SpelledWord &Word,
const syntax::TokenBuffer &TB) {
// Don't use heuristics if this is a real identifier.
// Unlikely identifiers are OK if they were used as identifiers nearby.
if (Word.ExpandedToken)
return nullptr;
2020-09-24 16:49:32 +08:00
// We don't want to handle words in string literals. (It'd be nice to list
// *allowed* token kinds explicitly, but comment Tokens aren't retained).
if (Word.PartOfSpelledToken &&
isStringLiteral(Word.PartOfSpelledToken->kind()))
return {};
const SourceManager &SM = TB.sourceManager();
// We prefer the closest possible token, line-wise. Backwards is penalized.
// Ties are implicitly broken by traversal order (first-one-wins).
auto File = SM.getFileID(Word.Location);
unsigned WordLine = SM.getSpellingLineNumber(Word.Location);
auto Cost = [&](SourceLocation Loc) -> unsigned {
assert(SM.getFileID(Loc) == File && "spelled token in wrong file?");
unsigned Line = SM.getSpellingLineNumber(Loc);
return Line >= WordLine ? Line - WordLine : 2 * (WordLine - Line);
};
const syntax::Token *BestTok = nullptr;
unsigned BestCost = -1;
// Search bounds are based on word length:
// - forward: 2^N lines
// - backward: 2^(N-1) lines.
unsigned MaxDistance =
1U << std::min<unsigned>(Word.Text.size(),
std::numeric_limits<unsigned>::digits - 1);
// Line number for SM.translateLineCol() should be one-based, also
// SM.translateLineCol() can handle line number greater than
// number of lines in the file.
// - LineMin = max(1, WordLine + 1 - 2^(N-1))
// - LineMax = WordLine + 1 + 2^N
unsigned LineMin =
WordLine + 1 <= MaxDistance / 2 ? 1 : WordLine + 1 - MaxDistance / 2;
unsigned LineMax = WordLine + 1 + MaxDistance;
SourceLocation LocMin = SM.translateLineCol(File, LineMin, 1);
assert(LocMin.isValid());
SourceLocation LocMax = SM.translateLineCol(File, LineMax, 1);
assert(LocMax.isValid());
// Updates BestTok and BestCost if Tok is a good candidate.
// May return true if the cost is too high for this token.
auto Consider = [&](const syntax::Token &Tok) {
if (Tok.location() < LocMin || Tok.location() > LocMax)
return true; // we are too far from the word, break the outer loop.
if (!(Tok.kind() == tok::identifier && Tok.text(SM) == Word.Text))
return false;
// No point guessing the same location we started with.
if (Tok.location() == Word.Location)
return false;
// We've done cheap checks, compute cost so we can break the caller's loop.
unsigned TokCost = Cost(Tok.location());
if (TokCost >= BestCost)
return true; // causes the outer loop to break.
// Allow locations that might be part of the AST, and macros (even if empty)
// but not things like disabled preprocessor sections.
if (!(tokenSpelledAt(Tok.location(), TB) || TB.expansionStartingAt(&Tok)))
return false;
// We already verified this token is an improvement.
BestCost = TokCost;
BestTok = &Tok;
return false;
};
auto SpelledTokens = TB.spelledTokens(File);
// Find where the word occurred in the token stream, to search forward & back.
auto *I = llvm::partition_point(SpelledTokens, [&](const syntax::Token &T) {
assert(SM.getFileID(T.location()) == SM.getFileID(Word.Location));
return T.location() < Word.Location; // Comparison OK: same file.
});
// Search for matches after the cursor.
for (const syntax::Token &Tok : llvm::makeArrayRef(I, SpelledTokens.end()))
if (Consider(Tok))
break; // costs of later tokens are greater...
// Search for matches before the cursor.
for (const syntax::Token &Tok :
llvm::reverse(llvm::makeArrayRef(SpelledTokens.begin(), I)))
if (Consider(Tok))
break;
if (BestTok)
vlog(
"Word {0} under cursor {1} isn't a token (after PP), trying nearby {2}",
Word.Text, Word.Location.printToString(SM),
BestTok->location().printToString(SM));
return BestTok;
}
std::vector<LocatedSymbol> locateSymbolAt(ParsedAST &AST, Position Pos,
const SymbolIndex *Index) {
const auto &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 {};
}
if (auto File = locateFileReferent(Pos, AST, *MainFilePath))
return {std::move(*File)};
auto CurLoc = sourceLocationInMainFile(SM, Pos);
if (!CurLoc) {
elog("locateSymbolAt failed to convert position to source location: {0}",
CurLoc.takeError());
return {};
}
const syntax::Token *TouchedIdentifier = nullptr;
auto TokensTouchingCursor =
syntax::spelledTokensTouching(*CurLoc, AST.getTokens());
for (const syntax::Token &Tok : TokensTouchingCursor) {
if (Tok.kind() == tok::identifier) {
if (auto Macro = locateMacroReferent(Tok, AST, *MainFilePath))
// Don't look at the AST or index if we have a macro result.
// (We'd just return declarations referenced from the macro's
// expansion.)
return {*std::move(Macro)};
TouchedIdentifier = &Tok;
break;
}
if (Tok.kind() == tok::kw_auto || Tok.kind() == tok::kw_decltype) {
// go-to-definition on auto should find the definition of the deduced
// type, if possible
if (auto Deduced = getDeducedType(AST.getASTContext(), Tok.location())) {
auto LocSym = locateSymbolForType(AST, *Deduced);
if (!LocSym.empty())
return LocSym;
}
}
}
ASTNodeKind NodeKind;
auto ASTResults = locateASTReferent(*CurLoc, TouchedIdentifier, AST,
*MainFilePath, Index, &NodeKind);
if (!ASTResults.empty())
return ASTResults;
// If the cursor can't be resolved directly, try fallback strategies.
auto Word =
SpelledWord::touching(*CurLoc, AST.getTokens(), AST.getLangOpts());
if (Word) {
// Is the same word nearby a real identifier that might refer to something?
if (const syntax::Token *NearbyIdent =
findNearbyIdentifier(*Word, AST.getTokens())) {
if (auto Macro = locateMacroReferent(*NearbyIdent, AST, *MainFilePath)) {
log("Found macro definition heuristically using nearby identifier {0}",
Word->Text);
return {*std::move(Macro)};
}
ASTResults =
locateASTReferent(NearbyIdent->location(), NearbyIdent, AST,
*MainFilePath, Index, /*NodeKind=*/nullptr);
if (!ASTResults.empty()) {
log("Found definition heuristically using nearby identifier {0}",
NearbyIdent->text(SM));
return ASTResults;
} else {
vlog("No definition found using nearby identifier {0} at {1}",
Word->Text, Word->Location.printToString(SM));
}
}
// No nearby word, or it didn't refer to anything either. Try the index.
auto TextualResults =
locateSymbolTextually(*Word, AST, Index, *MainFilePath, NodeKind);
if (!TextualResults.empty())
return TextualResults;
}
return {};
}
std::vector<DocumentLink> getDocumentLinks(ParsedAST &AST) {
const auto &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 links");
return {};
}
std::vector<DocumentLink> Result;
for (auto &Inc : AST.getIncludeStructure().MainFileIncludes) {
if (Inc.Resolved.empty())
continue;
auto HashLoc = SM.getComposedLoc(SM.getMainFileID(), Inc.HashOffset);
const auto *HashTok = AST.getTokens().spelledTokenAt(HashLoc);
assert(HashTok && "got inclusion at wrong offset");
const auto *IncludeTok = std::next(HashTok);
const auto *FileTok = std::next(IncludeTok);
// FileTok->range is not sufficient here, as raw lexing wouldn't yield
// correct tokens for angled filenames. Hence we explicitly use
// Inc.Written's length.
auto FileRange =
syntax::FileRange(SM, FileTok->location(), Inc.Written.length())
.toCharRange(SM);
Result.push_back(
DocumentLink({halfOpenToRange(SM, FileRange),
URIForFile::canonicalize(Inc.Resolved, *MainFilePath)}));
}
return Result;
}
namespace {
/// Collects references to symbols within the main file.
class ReferenceFinder : public index::IndexDataConsumer {
public:
struct Reference {
syntax::Token SpelledTok;
index::SymbolRoleSet Role;
Range range(const SourceManager &SM) const {
return halfOpenToRange(SM, SpelledTok.range(SM).toCharRange(SM));
}
};
ReferenceFinder(const ParsedAST &AST,
const std::vector<const NamedDecl *> &TargetDecls)
: AST(AST) {
for (const NamedDecl *D : TargetDecls)
CanonicalTargets.insert(D->getCanonicalDecl());
}
std::vector<Reference> take() && {
llvm::sort(References, [](const Reference &L, const Reference &R) {
auto LTok = L.SpelledTok.location();
auto RTok = R.SpelledTok.location();
return std::tie(LTok, L.Role) < std::tie(RTok, R.Role);
});
// We sometimes see duplicates when parts of the AST get traversed twice.
References.erase(std::unique(References.begin(), References.end(),
[](const Reference &L, const Reference &R) {
auto LTok = L.SpelledTok.location();
auto RTok = R.SpelledTok.location();
return std::tie(LTok, L.Role) ==
std::tie(RTok, R.Role);
}),
References.end());
return std::move(References);
}
bool
handleDeclOccurrence(const Decl *D, index::SymbolRoleSet Roles,
llvm::ArrayRef<index::SymbolRelation> Relations,
SourceLocation Loc,
index::IndexDataConsumer::ASTNodeInfo ASTNode) override {
assert(D->isCanonicalDecl() && "expect D to be a canonical declaration");
const SourceManager &SM = AST.getSourceManager();
if (!CanonicalTargets.count(D) || !isInsideMainFile(Loc, SM))
return true;
const auto &TB = AST.getTokens();
Loc = SM.getFileLoc(Loc);
if (const auto *Tok = TB.spelledTokenAt(Loc))
References.push_back({*Tok, Roles});
return true;
}
private:
llvm::SmallSet<const Decl *, 4> CanonicalTargets;
std::vector<Reference> References;
const ParsedAST &AST;
};
std::vector<ReferenceFinder::Reference>
findRefs(const std::vector<const NamedDecl *> &Decls, ParsedAST &AST) {
ReferenceFinder RefFinder(AST, Decls);
index::IndexingOptions IndexOpts;
IndexOpts.SystemSymbolFilter =
index::IndexingOptions::SystemSymbolFilterKind::All;
IndexOpts.IndexFunctionLocals = true;
IndexOpts.IndexParametersInDeclarations = true;
IndexOpts.IndexTemplateParameters = true;
indexTopLevelDecls(AST.getASTContext(), AST.getPreprocessor(),
AST.getLocalTopLevelDecls(), RefFinder, IndexOpts);
return std::move(RefFinder).take();
}
const Stmt *getFunctionBody(DynTypedNode N) {
if (const auto *FD = N.get<FunctionDecl>())
return FD->getBody();
if (const auto *FD = N.get<BlockDecl>())
return FD->getBody();
if (const auto *FD = N.get<LambdaExpr>())
return FD->getBody();
if (const auto *FD = N.get<ObjCMethodDecl>())
return FD->getBody();
return nullptr;
}
const Stmt *getLoopBody(DynTypedNode N) {
if (const auto *LS = N.get<ForStmt>())
return LS->getBody();
if (const auto *LS = N.get<CXXForRangeStmt>())
return LS->getBody();
if (const auto *LS = N.get<WhileStmt>())
return LS->getBody();
if (const auto *LS = N.get<DoStmt>())
return LS->getBody();
return nullptr;
}
// AST traversal to highlight control flow statements under some root.
// Once we hit further control flow we prune the tree (or at least restrict
// what we highlight) so we capture e.g. breaks from the outer loop only.
class FindControlFlow : public RecursiveASTVisitor<FindControlFlow> {
// Types of control-flow statements we might highlight.
enum Target {
Break = 1,
Continue = 2,
Return = 4,
Case = 8,
Throw = 16,
Goto = 32,
All = Break | Continue | Return | Case | Throw | Goto,
};
int Ignore = 0; // bitmask of Target - what are we *not* highlighting?
SourceRange Bounds; // Half-open, restricts reported targets.
std::vector<SourceLocation> &Result;
const SourceManager &SM;
// Masks out targets for a traversal into D.
// Traverses the subtree using Delegate() if any targets remain.
template <typename Func>
bool filterAndTraverse(DynTypedNode D, const Func &Delegate) {
auto RestoreIgnore = llvm::make_scope_exit(
[OldIgnore(Ignore), this] { Ignore = OldIgnore; });
if (getFunctionBody(D))
Ignore = All;
else if (getLoopBody(D))
Ignore |= Continue | Break;
else if (D.get<SwitchStmt>())
Ignore |= Break | Case;
// Prune tree if we're not looking for anything.
return (Ignore == All) ? true : Delegate();
}
void found(Target T, SourceLocation Loc) {
if (T & Ignore)
return;
if (SM.isBeforeInTranslationUnit(Loc, Bounds.getBegin()) ||
SM.isBeforeInTranslationUnit(Bounds.getEnd(), Loc))
return;
Result.push_back(Loc);
}
public:
FindControlFlow(SourceRange Bounds, std::vector<SourceLocation> &Result,
const SourceManager &SM)
: Bounds(Bounds), Result(Result), SM(SM) {}
// When traversing function or loops, limit targets to those that still
// refer to the original root.
bool TraverseDecl(Decl *D) {
return !D || filterAndTraverse(DynTypedNode::create(*D), [&] {
return RecursiveASTVisitor::TraverseDecl(D);
});
}
bool TraverseStmt(Stmt *S) {
return !S || filterAndTraverse(DynTypedNode::create(*S), [&] {
return RecursiveASTVisitor::TraverseStmt(S);
});
}
// Add leaves that we found and want.
bool VisitReturnStmt(ReturnStmt *R) {
found(Return, R->getReturnLoc());
return true;
}
bool VisitBreakStmt(BreakStmt *B) {
found(Break, B->getBreakLoc());
return true;
}
bool VisitContinueStmt(ContinueStmt *C) {
found(Continue, C->getContinueLoc());
return true;
}
bool VisitSwitchCase(SwitchCase *C) {
found(Case, C->getKeywordLoc());
return true;
}
bool VisitCXXThrowExpr(CXXThrowExpr *T) {
found(Throw, T->getThrowLoc());
return true;
}
bool VisitGotoStmt(GotoStmt *G) {
// Goto is interesting if its target is outside the root.
if (const auto *LD = G->getLabel()) {
if (SM.isBeforeInTranslationUnit(LD->getLocation(), Bounds.getBegin()) ||
SM.isBeforeInTranslationUnit(Bounds.getEnd(), LD->getLocation()))
found(Goto, G->getGotoLoc());
}
return true;
}
};
// Given a location within a switch statement, return the half-open range that
// covers the case it's contained in.
// We treat `case X: case Y: ...` as one case, and assume no other fallthrough.
SourceRange findCaseBounds(const SwitchStmt &Switch, SourceLocation Loc,
const SourceManager &SM) {
// Cases are not stored in order, sort them first.
// (In fact they seem to be stored in reverse order, don't rely on this)
std::vector<const SwitchCase *> Cases;
for (const SwitchCase *Case = Switch.getSwitchCaseList(); Case;
Case = Case->getNextSwitchCase())
Cases.push_back(Case);
llvm::sort(Cases, [&](const SwitchCase *L, const SwitchCase *R) {
return SM.isBeforeInTranslationUnit(L->getKeywordLoc(), R->getKeywordLoc());
});
// Find the first case after the target location, the end of our range.
auto CaseAfter = llvm::partition_point(Cases, [&](const SwitchCase *C) {
return !SM.isBeforeInTranslationUnit(Loc, C->getKeywordLoc());
});
SourceLocation End = CaseAfter == Cases.end() ? Switch.getEndLoc()
: (*CaseAfter)->getKeywordLoc();
// Our target can be before the first case - cases are optional!
if (CaseAfter == Cases.begin())
return SourceRange(Switch.getBeginLoc(), End);
// The start of our range is usually the previous case, but...
auto CaseBefore = std::prev(CaseAfter);
// ... rewind CaseBefore to the first in a `case A: case B: ...` sequence.
while (CaseBefore != Cases.begin() &&
(*std::prev(CaseBefore))->getSubStmt() == *CaseBefore)
--CaseBefore;
return SourceRange((*CaseBefore)->getKeywordLoc(), End);
}
// Returns the locations of control flow statements related to N. e.g.:
// for => branches: break/continue/return/throw
// break => controlling loop (forwhile/do), and its related control flow
// return => all returns/throws from the same function
// When an inner block is selected, we include branches bound to outer blocks
// as these are exits from the inner block. e.g. return in a for loop.
// FIXME: We don't analyze catch blocks, throw is treated the same as return.
std::vector<SourceLocation> relatedControlFlow(const SelectionTree::Node &N) {
const SourceManager &SM =
N.getDeclContext().getParentASTContext().getSourceManager();
std::vector<SourceLocation> Result;
// First, check if we're at a node that can resolve to a root.
enum class Cur { None, Break, Continue, Return, Case, Throw } Cursor;
if (N.ASTNode.get<BreakStmt>()) {
Cursor = Cur::Break;
} else if (N.ASTNode.get<ContinueStmt>()) {
Cursor = Cur::Continue;
} else if (N.ASTNode.get<ReturnStmt>()) {
Cursor = Cur::Return;
} else if (N.ASTNode.get<CXXThrowExpr>()) {
Cursor = Cur::Throw;
} else if (N.ASTNode.get<SwitchCase>()) {
Cursor = Cur::Case;
} else if (const GotoStmt *GS = N.ASTNode.get<GotoStmt>()) {
// We don't know what root to associate with, but highlight the goto/label.
Result.push_back(GS->getGotoLoc());
if (const auto *LD = GS->getLabel())
Result.push_back(LD->getLocation());
Cursor = Cur::None;
} else {
Cursor = Cur::None;
}
const Stmt *Root = nullptr; // Loop or function body to traverse.
SourceRange Bounds;
// Look up the tree for a root (or just at this node if we didn't find a leaf)
for (const auto *P = &N; P; P = P->Parent) {
// return associates with enclosing function
if (const Stmt *FunctionBody = getFunctionBody(P->ASTNode)) {
if (Cursor == Cur::Return || Cursor == Cur::Throw) {
Root = FunctionBody;
}
break; // other leaves don't cross functions.
}
// break/continue associate with enclosing loop.
if (const Stmt *LoopBody = getLoopBody(P->ASTNode)) {
if (Cursor == Cur::None || Cursor == Cur::Break ||
Cursor == Cur::Continue) {
Root = LoopBody;
// Highlight the loop keyword itself.
// FIXME: for do-while, this only covers the `do`..
Result.push_back(P->ASTNode.getSourceRange().getBegin());
break;
}
}
// For switches, users think of case statements as control flow blocks.
// We highlight only occurrences surrounded by the same case.
// We don't detect fallthrough (other than 'case X, case Y').
if (const auto *SS = P->ASTNode.get<SwitchStmt>()) {
if (Cursor == Cur::Break || Cursor == Cur::Case) {
Result.push_back(SS->getSwitchLoc()); // Highlight the switch.
Root = SS->getBody();
// Limit to enclosing case, if there is one.
Bounds = findCaseBounds(*SS, N.ASTNode.getSourceRange().getBegin(), SM);
break;
}
}
// If we didn't start at some interesting node, we're done.
if (Cursor == Cur::None)
break;
}
if (Root) {
if (!Bounds.isValid())
Bounds = Root->getSourceRange();
FindControlFlow(Bounds, Result, SM).TraverseStmt(const_cast<Stmt *>(Root));
}
return Result;
}
DocumentHighlight toHighlight(const ReferenceFinder::Reference &Ref,
const SourceManager &SM) {
DocumentHighlight DH;
DH.range = Ref.range(SM);
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;
return DH;
}
llvm::Optional<DocumentHighlight> toHighlight(SourceLocation Loc,
const syntax::TokenBuffer &TB) {
Loc = TB.sourceManager().getFileLoc(Loc);
if (const auto *Tok = TB.spelledTokenAt(Loc)) {
DocumentHighlight Result;
Result.range = halfOpenToRange(
TB.sourceManager(),
CharSourceRange::getCharRange(Tok->location(), Tok->endLocation()));
return Result;
}
return llvm::None;
}
} // namespace
std::vector<DocumentHighlight> findDocumentHighlights(ParsedAST &AST,
Position Pos) {
const SourceManager &SM = AST.getSourceManager();
// FIXME: show references to macro within file?
auto CurLoc = sourceLocationInMainFile(SM, Pos);
if (!CurLoc) {
llvm::consumeError(CurLoc.takeError());
return {};
}
std::vector<DocumentHighlight> Result;
auto TryTree = [&](SelectionTree ST) {
if (const SelectionTree::Node *N = ST.commonAncestor()) {
DeclRelationSet Relations =
DeclRelation::TemplatePattern | DeclRelation::Alias;
auto Decls = targetDecl(N->ASTNode, Relations);
if (!Decls.empty()) {
// FIXME: we may get multiple DocumentHighlights with the same location
// and different kinds, deduplicate them.
for (const auto &Ref : findRefs({Decls.begin(), Decls.end()}, AST))
Result.push_back(toHighlight(Ref, SM));
return true;
}
auto ControlFlow = relatedControlFlow(*N);
if (!ControlFlow.empty()) {
for (SourceLocation Loc : ControlFlow)
if (auto Highlight = toHighlight(Loc, AST.getTokens()))
Result.push_back(std::move(*Highlight));
return true;
}
}
return false;
};
unsigned Offset =
AST.getSourceManager().getDecomposedSpellingLoc(*CurLoc).second;
SelectionTree::createEach(AST.getASTContext(), AST.getTokens(), Offset,
Offset, TryTree);
return Result;
}
std::vector<LocatedSymbol> findImplementations(ParsedAST &AST, Position Pos,
const SymbolIndex *Index) {
// We rely on index to find the implementations in subclasses.
// FIXME: Index can be stale, so we may loose some latest results from the
// main file.
if (!Index)
return {};
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 implementations.");
return {};
}
auto CurLoc = sourceLocationInMainFile(SM, Pos);
if (!CurLoc) {
elog("Failed to convert position to source location: {0}",
CurLoc.takeError());
return {};
}
DeclRelationSet Relations =
DeclRelation::TemplatePattern | DeclRelation::Alias;
llvm::DenseSet<SymbolID> IDs;
RelationKind QueryKind;
for (const NamedDecl *ND : getDeclAtPosition(AST, *CurLoc, Relations)) {
if (const auto *CXXMD = llvm::dyn_cast<CXXMethodDecl>(ND)) {
if (CXXMD->isVirtual()) {
IDs.insert(getSymbolID(ND));
QueryKind = RelationKind::OverriddenBy;
}
} else if (const auto *RD = dyn_cast<CXXRecordDecl>(ND)) {
IDs.insert(getSymbolID(RD));
QueryKind = RelationKind::BaseOf;
}
}
return findImplementors(std::move(IDs), QueryKind, Index, *MainFilePath);
}
ReferencesResult findReferences(ParsedAST &AST, Position Pos, uint32_t Limit,
const SymbolIndex *Index) {
if (!Limit)
Limit = std::numeric_limits<uint32_t>::max();
ReferencesResult 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 URIMainFile = URIForFile::canonicalize(*MainFilePath, *MainFilePath);
auto CurLoc = sourceLocationInMainFile(SM, Pos);
if (!CurLoc) {
llvm::consumeError(CurLoc.takeError());
return {};
}
llvm::Optional<DefinedMacro> Macro;
if (const auto *IdentifierAtCursor =
syntax::spelledIdentifierTouching(*CurLoc, AST.getTokens())) {
Macro = locateMacroAt(*IdentifierAtCursor, AST.getPreprocessor());
}
RefsRequest Req;
if (Macro) {
// Handle references to macro.
if (auto MacroSID = getSymbolID(Macro->Name, Macro->Info, SM)) {
// Collect macro references from main file.
const auto &IDToRefs = AST.getMacros().MacroRefs;
auto Refs = IDToRefs.find(MacroSID);
if (Refs != IDToRefs.end()) {
for (const auto &Ref : Refs->second) {
Location Result;
Result.range = Ref;
Result.uri = URIMainFile;
Results.References.push_back(std::move(Result));
}
}
Req.IDs.insert(MacroSID);
}
} else {
// Handle references to Decls.
DeclRelationSet Relations =
DeclRelation::TemplatePattern | DeclRelation::Alias;
std::vector<const NamedDecl *> Decls =
getDeclAtPosition(AST, *CurLoc, Relations);
// We traverse the AST to find references in the main file.
auto MainFileRefs = findRefs(Decls, AST);
// We may get multiple refs with the same location and different Roles, as
// cross-reference is only interested in locations, we deduplicate them
// by the location to avoid emitting duplicated locations.
MainFileRefs.erase(std::unique(MainFileRefs.begin(), MainFileRefs.end(),
[](const ReferenceFinder::Reference &L,
const ReferenceFinder::Reference &R) {
return L.SpelledTok.location() ==
R.SpelledTok.location();
}),
MainFileRefs.end());
for (const auto &Ref : MainFileRefs) {
Location Result;
Result.range = Ref.range(SM);
Result.uri = URIMainFile;
Results.References.push_back(std::move(Result));
}
if (Index && Results.References.size() <= Limit) {
for (const Decl *D : Decls) {
// Not all symbols can be referenced from outside (e.g.
// function-locals).
// TODO: we could skip TU-scoped symbols here (e.g. static functions) if
// we know this file isn't a header. The details might be tricky.
if (D->getParentFunctionOrMethod())
continue;
if (auto ID = getSymbolID(D))
Req.IDs.insert(ID);
}
}
}
// Now query the index for references from other files.
if (!Req.IDs.empty() && Index && Results.References.size() <= Limit) {
Req.Limit = Limit;
Results.HasMore |= Index->refs(Req, [&](const Ref &R) {
// No need to continue process if we reach the limit.
if (Results.References.size() > Limit)
return;
auto LSPLoc = toLSPLocation(R.Location, *MainFilePath);
// Avoid indexed results for the main file - the AST is authoritative.
if (!LSPLoc || LSPLoc->uri.file() == *MainFilePath)
return;
Results.References.push_back(std::move(*LSPLoc));
});
}
if (Results.References.size() > Limit) {
Results.HasMore = true;
Results.References.resize(Limit);
}
return Results;
}
std::vector<SymbolDetails> getSymbolInfo(ParsedAST &AST, Position Pos) {
const SourceManager &SM = AST.getSourceManager();
auto CurLoc = sourceLocationInMainFile(SM, Pos);
if (!CurLoc) {
llvm::consumeError(CurLoc.takeError());
return {};
}
std::vector<SymbolDetails> Results;
// We also want the targets of using-decls, so we include
// DeclRelation::Underlying.
DeclRelationSet Relations = DeclRelation::TemplatePattern |
DeclRelation::Alias | DeclRelation::Underlying;
for (const NamedDecl *D : getDeclAtPosition(AST, *CurLoc, Relations)) {
SymbolDetails NewSymbol;
std::string QName = printQualifiedName(*D);
auto SplitQName = splitQualifiedName(QName);
NewSymbol.containerName = std::string(SplitQName.first);
NewSymbol.name = std::string(SplitQName.second);
if (NewSymbol.containerName.empty()) {
if (const auto *ParentND =
dyn_cast_or_null<NamedDecl>(D->getDeclContext()))
NewSymbol.containerName = printQualifiedName(*ParentND);
}
llvm::SmallString<32> USR;
if (!index::generateUSRForDecl(D, USR)) {
NewSymbol.USR = std::string(USR.str());
NewSymbol.ID = SymbolID(NewSymbol.USR);
}
Results.push_back(std::move(NewSymbol));
}
const auto *IdentifierAtCursor =
syntax::spelledIdentifierTouching(*CurLoc, AST.getTokens());
if (!IdentifierAtCursor)
return Results;
if (auto M = locateMacroAt(*IdentifierAtCursor, AST.getPreprocessor())) {
SymbolDetails NewMacro;
NewMacro.name = std::string(M->Name);
llvm::SmallString<32> USR;
if (!index::generateUSRForMacro(NewMacro.name, M->Info->getDefinitionLoc(),
SM, USR)) {
NewMacro.USR = std::string(USR.str());
NewMacro.ID = SymbolID(NewMacro.USR);
}
Results.push_back(std::move(NewMacro));
}
return Results;
}
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const LocatedSymbol &S) {
OS << S.Name << ": " << S.PreferredDeclaration;
if (S.Definition)
OS << " def=" << *S.Definition;
return OS;
}
template <typename HierarchyItem>
static llvm::Optional<HierarchyItem> declToHierarchyItem(const NamedDecl &ND) {
ASTContext &Ctx = ND.getASTContext();
auto &SM = Ctx.getSourceManager();
SourceLocation NameLoc = nameLocation(ND, Ctx.getSourceManager());
SourceLocation BeginLoc = SM.getSpellingLoc(SM.getFileLoc(ND.getBeginLoc()));
SourceLocation EndLoc = SM.getSpellingLoc(SM.getFileLoc(ND.getEndLoc()));
const auto DeclRange =
toHalfOpenFileRange(SM, Ctx.getLangOpts(), {BeginLoc, EndLoc});
if (!DeclRange)
return llvm::None;
auto FilePath =
getCanonicalPath(SM.getFileEntryForID(SM.getFileID(NameLoc)), SM);
auto TUPath = getCanonicalPath(SM.getFileEntryForID(SM.getMainFileID()), SM);
if (!FilePath || !TUPath)
return llvm::None; // Not useful without a uri.
Position NameBegin = sourceLocToPosition(SM, NameLoc);
Position NameEnd = sourceLocToPosition(
SM, Lexer::getLocForEndOfToken(NameLoc, 0, SM, Ctx.getLangOpts()));
index::SymbolInfo SymInfo = index::getSymbolInfo(&ND);
// FIXME: This is not classifying constructors, destructors and operators
// correctly.
SymbolKind SK = indexSymbolKindToSymbolKind(SymInfo.Kind);
HierarchyItem HI;
HI.name = printName(Ctx, ND);
HI.kind = SK;
HI.range = Range{sourceLocToPosition(SM, DeclRange->getBegin()),
sourceLocToPosition(SM, DeclRange->getEnd())};
HI.selectionRange = Range{NameBegin, NameEnd};
if (!HI.range.contains(HI.selectionRange)) {
// 'selectionRange' must be contained in 'range', so in cases where clang
// reports unrelated ranges we need to reconcile somehow.
HI.range = HI.selectionRange;
}
HI.uri = URIForFile::canonicalize(*FilePath, *TUPath);
// Compute the SymbolID and store it in the 'data' field.
// This allows typeHierarchy/resolve to be used to
// resolve children of items returned in a previous request
// for parents.
if (auto ID = getSymbolID(&ND))
HI.data = ID.str();
return HI;
}
static llvm::Optional<TypeHierarchyItem>
declToTypeHierarchyItem(const NamedDecl &ND) {
auto Result = declToHierarchyItem<TypeHierarchyItem>(ND);
if (Result)
Result->deprecated = ND.isDeprecated();
return Result;
}
static llvm::Optional<CallHierarchyItem>
declToCallHierarchyItem(const NamedDecl &ND) {
auto Result = declToHierarchyItem<CallHierarchyItem>(ND);
if (Result && ND.isDeprecated())
Result->tags.push_back(SymbolTag::Deprecated);
return Result;
}
template <typename HierarchyItem>
static llvm::Optional<HierarchyItem> symbolToHierarchyItem(const Symbol &S,
PathRef TUPath) {
auto Loc = symbolToLocation(S, TUPath);
if (!Loc) {
elog("Failed to convert symbol to hierarchy item: {0}", Loc.takeError());
return llvm::None;
}
HierarchyItem HI;
HI.name = std::string(S.Name);
HI.kind = indexSymbolKindToSymbolKind(S.SymInfo.Kind);
HI.selectionRange = Loc->range;
// FIXME: Populate 'range' correctly
// (https://github.com/clangd/clangd/issues/59).
HI.range = HI.selectionRange;
HI.uri = Loc->uri;
// Store the SymbolID in the 'data' field. The client will
// send this back in requests to resolve additional levels
// of the hierarchy.
HI.data = S.ID.str();
return HI;
}
static llvm::Optional<TypeHierarchyItem>
symbolToTypeHierarchyItem(const Symbol &S, PathRef TUPath) {
auto Result = symbolToHierarchyItem<TypeHierarchyItem>(S, TUPath);
if (Result)
Result->deprecated = (S.Flags & Symbol::Deprecated);
return Result;
}
static llvm::Optional<CallHierarchyItem>
symbolToCallHierarchyItem(const Symbol &S, PathRef TUPath) {
auto Result = symbolToHierarchyItem<CallHierarchyItem>(S, TUPath);
if (Result && (S.Flags & Symbol::Deprecated))
Result->tags.push_back(SymbolTag::Deprecated);
return Result;
}
static void fillSubTypes(const SymbolID &ID,
std::vector<TypeHierarchyItem> &SubTypes,
const SymbolIndex *Index, int Levels, PathRef TUPath) {
RelationsRequest Req;
Req.Subjects.insert(ID);
Req.Predicate = RelationKind::BaseOf;
Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) {
if (Optional<TypeHierarchyItem> ChildSym =
symbolToTypeHierarchyItem(Object, TUPath)) {
if (Levels > 1) {
ChildSym->children.emplace();
fillSubTypes(Object.ID, *ChildSym->children, Index, Levels - 1, TUPath);
}
SubTypes.emplace_back(std::move(*ChildSym));
}
});
}
using RecursionProtectionSet = llvm::SmallSet<const CXXRecordDecl *, 4>;
static void fillSuperTypes(const CXXRecordDecl &CXXRD, ASTContext &ASTCtx,
std::vector<TypeHierarchyItem> &SuperTypes,
RecursionProtectionSet &RPSet) {
// typeParents() will replace dependent template specializations
// with their class template, so to avoid infinite recursion for
// certain types of hierarchies, keep the templates encountered
// along the parent chain in a set, and stop the recursion if one
// starts to repeat.
auto *Pattern = CXXRD.getDescribedTemplate() ? &CXXRD : nullptr;
if (Pattern) {
if (!RPSet.insert(Pattern).second) {
return;
}
}
for (const CXXRecordDecl *ParentDecl : typeParents(&CXXRD)) {
if (Optional<TypeHierarchyItem> ParentSym =
declToTypeHierarchyItem(*ParentDecl)) {
ParentSym->parents.emplace();
fillSuperTypes(*ParentDecl, ASTCtx, *ParentSym->parents, RPSet);
SuperTypes.emplace_back(std::move(*ParentSym));
}
}
if (Pattern) {
RPSet.erase(Pattern);
}
}
const CXXRecordDecl *findRecordTypeAt(ParsedAST &AST, Position Pos) {
auto RecordFromNode =
[](const SelectionTree::Node *N) -> const CXXRecordDecl * {
if (!N)
return nullptr;
// Note: explicitReferenceTargets() will search for both template
// instantiations and template patterns, and prefer the former if available
// (generally, one will be available for non-dependent specializations of a
// class template).
auto Decls = explicitReferenceTargets(N->ASTNode, DeclRelation::Underlying);
if (Decls.empty())
return nullptr;
const NamedDecl *D = Decls[0];
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
// If this is a variable, use the type of the variable.
return VD->getType().getTypePtr()->getAsCXXRecordDecl();
}
if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
// If this is a method, use the type of the class.
return Method->getParent();
}
// We don't handle FieldDecl because it's not clear what behaviour
// the user would expect: the enclosing class type (as with a
// method), or the field's type (as with a variable).
return dyn_cast<CXXRecordDecl>(D);
};
const SourceManager &SM = AST.getSourceManager();
const CXXRecordDecl *Result = nullptr;
auto Offset = positionToOffset(SM.getBufferData(SM.getMainFileID()), Pos);
if (!Offset) {
llvm::consumeError(Offset.takeError());
return Result;
}
SelectionTree::createEach(AST.getASTContext(), AST.getTokens(), *Offset,
*Offset, [&](SelectionTree ST) {
Result = RecordFromNode(ST.commonAncestor());
return Result != nullptr;
});
return Result;
}
std::vector<const CXXRecordDecl *> typeParents(const CXXRecordDecl *CXXRD) {
std::vector<const CXXRecordDecl *> Result;
// If this is an invalid instantiation, instantiation of the bases
// may not have succeeded, so fall back to the template pattern.
if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(CXXRD)) {
if (CTSD->isInvalidDecl())
CXXRD = CTSD->getSpecializedTemplate()->getTemplatedDecl();
}
// Can't query bases without a definition.
if (!CXXRD->hasDefinition())
return Result;
for (auto Base : CXXRD->bases()) {
const CXXRecordDecl *ParentDecl = nullptr;
const Type *Type = Base.getType().getTypePtr();
if (const RecordType *RT = Type->getAs<RecordType>()) {
ParentDecl = RT->getAsCXXRecordDecl();
}
if (!ParentDecl) {
// Handle a dependent base such as "Base<T>" by using the primary
// template.
if (const TemplateSpecializationType *TS =
Type->getAs<TemplateSpecializationType>()) {
TemplateName TN = TS->getTemplateName();
if (TemplateDecl *TD = TN.getAsTemplateDecl()) {
ParentDecl = dyn_cast<CXXRecordDecl>(TD->getTemplatedDecl());
}
}
}
if (ParentDecl)
Result.push_back(ParentDecl);
}
return Result;
}
llvm::Optional<TypeHierarchyItem>
getTypeHierarchy(ParsedAST &AST, Position Pos, int ResolveLevels,
TypeHierarchyDirection Direction, const SymbolIndex *Index,
PathRef TUPath) {
const CXXRecordDecl *CXXRD = findRecordTypeAt(AST, Pos);
if (!CXXRD)
return llvm::None;
bool WantParents = Direction == TypeHierarchyDirection::Parents ||
Direction == TypeHierarchyDirection::Both;
bool WantChildren = Direction == TypeHierarchyDirection::Children ||
Direction == TypeHierarchyDirection::Both;
// If we're looking for children, we're doing the lookup in the index.
// The index does not store relationships between implicit
// specializations, so if we have one, use the template pattern instead.
// Note that this needs to be done before the declToTypeHierarchyItem(),
// otherwise the type hierarchy item would misleadingly contain the
// specialization parameters, while the children would involve classes
// that derive from other specializations of the template.
if (WantChildren) {
if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(CXXRD))
CXXRD = CTSD->getTemplateInstantiationPattern();
}
Optional<TypeHierarchyItem> Result = declToTypeHierarchyItem(*CXXRD);
if (!Result)
return Result;
if (WantParents) {
Result->parents.emplace();
RecursionProtectionSet RPSet;
fillSuperTypes(*CXXRD, AST.getASTContext(), *Result->parents, RPSet);
}
if (WantChildren && ResolveLevels > 0) {
Result->children.emplace();
if (Index) {
if (auto ID = getSymbolID(CXXRD))
fillSubTypes(ID, *Result->children, Index, ResolveLevels, TUPath);
}
}
return Result;
}
void resolveTypeHierarchy(TypeHierarchyItem &Item, int ResolveLevels,
TypeHierarchyDirection Direction,
const SymbolIndex *Index) {
// We only support typeHierarchy/resolve for children, because for parents
// we ignore ResolveLevels and return all levels of parents eagerly.
if (Direction == TypeHierarchyDirection::Parents || ResolveLevels == 0)
return;
Item.children.emplace();
if (Index && Item.data) {
// We store the item's SymbolID in the 'data' field, and the client
// passes it back to us in typeHierarchy/resolve.
if (Expected<SymbolID> ID = SymbolID::fromStr(*Item.data)) {
fillSubTypes(*ID, *Item.children, Index, ResolveLevels, Item.uri.file());
}
}
}
std::vector<CallHierarchyItem>
prepareCallHierarchy(ParsedAST &AST, Position Pos, PathRef TUPath) {
std::vector<CallHierarchyItem> Result;
const auto &SM = AST.getSourceManager();
auto Loc = sourceLocationInMainFile(SM, Pos);
if (!Loc) {
elog("prepareCallHierarchy failed to convert position to source location: "
"{0}",
Loc.takeError());
return Result;
}
for (const NamedDecl *Decl : getDeclAtPosition(AST, *Loc, {})) {
if (!Decl->isFunctionOrFunctionTemplate())
continue;
if (auto CHI = declToCallHierarchyItem(*Decl))
Result.emplace_back(std::move(*CHI));
}
return Result;
}
std::vector<CallHierarchyIncomingCall>
incomingCalls(const CallHierarchyItem &Item, const SymbolIndex *Index) {
std::vector<CallHierarchyIncomingCall> Results;
if (!Index || Item.data.empty())
return Results;
auto ID = SymbolID::fromStr(Item.data);
if (!ID) {
elog("incomingCalls failed to find symbol: {0}", ID.takeError());
return Results;
}
// In this function, we find incoming calls based on the index only.
// In principle, the AST could have more up-to-date information about
// occurrences within the current file. However, going from a SymbolID
// to an AST node isn't cheap, particularly when the declaration isn't
// in the main file.
// FIXME: Consider also using AST information when feasible.
RefsRequest Request;
Request.IDs.insert(*ID);
// We could restrict more specifically to calls by introducing a new RefKind,
// but non-call references (such as address-of-function) can still be
// interesting as they can indicate indirect calls.
Request.Filter = RefKind::Reference;
// Initially store the ranges in a map keyed by SymbolID of the caller.
// This allows us to group different calls with the same caller
// into the same CallHierarchyIncomingCall.
llvm::DenseMap<SymbolID, std::vector<Range>> CallsIn;
// We can populate the ranges based on a refs request only. As we do so, we
// also accumulate the container IDs into a lookup request.
LookupRequest ContainerLookup;
Index->refs(Request, [&](const Ref &R) {
auto Loc = indexToLSPLocation(R.Location, Item.uri.file());
if (!Loc) {
elog("incomingCalls failed to convert location: {0}", Loc.takeError());
return;
}
auto It = CallsIn.try_emplace(R.Container, std::vector<Range>{}).first;
It->second.push_back(Loc->range);
ContainerLookup.IDs.insert(R.Container);
});
// Perform the lookup request and combine its results with CallsIn to
// get complete CallHierarchyIncomingCall objects.
Index->lookup(ContainerLookup, [&](const Symbol &Caller) {
auto It = CallsIn.find(Caller.ID);
assert(It != CallsIn.end());
if (auto CHI = symbolToCallHierarchyItem(Caller, Item.uri.file()))
Results.push_back(
CallHierarchyIncomingCall{std::move(*CHI), std::move(It->second)});
});
// Sort results by name of container.
llvm::sort(Results, [](const CallHierarchyIncomingCall &A,
const CallHierarchyIncomingCall &B) {
return A.from.name < B.from.name;
});
return Results;
}
llvm::DenseSet<const Decl *> getNonLocalDeclRefs(ParsedAST &AST,
const FunctionDecl *FD) {
if (!FD->hasBody())
return {};
llvm::DenseSet<const Decl *> DeclRefs;
findExplicitReferences(FD, [&](ReferenceLoc Ref) {
for (const Decl *D : Ref.Targets) {
if (!index::isFunctionLocalSymbol(D) && !D->isTemplateParameter() &&
!Ref.IsDecl)
DeclRefs.insert(D);
}
});
return DeclRefs;
}
} // namespace clangd
} // namespace clang