blob: e3e2ab3ea86947ad6fa694d08d980056c943a0b7 [file] [log] [blame]
//===--- HeaderSourceSwitch.cpp - --------------------------------*- C++-*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "HeaderSourceSwitch.h"
#include "AST.h"
#include "SourceCode.h"
#include "index/SymbolCollector.h"
#include "support/Logger.h"
#include "clang/AST/Decl.h"
namespace clang {
namespace clangd {
llvm::Optional<Path> getCorrespondingHeaderOrSource(
PathRef OriginalFile, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
llvm::StringRef SourceExtensions[] = {".cpp", ".c", ".cc", ".cxx",
".c++", ".m", ".mm"};
llvm::StringRef HeaderExtensions[] = {".h", ".hh", ".hpp", ".hxx", ".inc"};
llvm::StringRef PathExt = llvm::sys::path::extension(OriginalFile);
// Lookup in a list of known extensions.
auto SourceIter =
llvm::find_if(SourceExtensions, [&PathExt](PathRef SourceExt) {
return SourceExt.equals_insensitive(PathExt);
bool IsSource = SourceIter != std::end(SourceExtensions);
auto HeaderIter =
llvm::find_if(HeaderExtensions, [&PathExt](PathRef HeaderExt) {
return HeaderExt.equals_insensitive(PathExt);
bool IsHeader = HeaderIter != std::end(HeaderExtensions);
// We can only switch between the known extensions.
if (!IsSource && !IsHeader)
return None;
// Array to lookup extensions for the switch. An opposite of where original
// extension was found.
llvm::ArrayRef<llvm::StringRef> NewExts;
if (IsSource)
NewExts = HeaderExtensions;
NewExts = SourceExtensions;
// Storage for the new path.
llvm::SmallString<128> NewPath = OriginalFile;
// Loop through switched extension candidates.
for (llvm::StringRef NewExt : NewExts) {
llvm::sys::path::replace_extension(NewPath, NewExt);
if (VFS->exists(NewPath))
return Path(NewPath);
// Also check NewExt in upper-case, just in case.
llvm::sys::path::replace_extension(NewPath, NewExt.upper());
if (VFS->exists(NewPath))
return Path(NewPath);
return None;
llvm::Optional<Path> getCorrespondingHeaderOrSource(PathRef OriginalFile,
ParsedAST &AST,
const SymbolIndex *Index) {
if (!Index) {
// FIXME: use the AST to do the inference.
return None;
LookupRequest Request;
// Find all symbols present in the original file.
for (const auto *D : getIndexableLocalDecls(AST)) {
if (auto ID = getSymbolID(D))
llvm::StringMap<int> Candidates; // Target path => score.
auto AwardTarget = [&](const char *TargetURI) {
if (auto TargetPath = URI::resolve(TargetURI, OriginalFile)) {
if (*TargetPath != OriginalFile) // exclude the original file.
} else {
elog("Failed to resolve URI {0}: {1}", TargetURI, TargetPath.takeError());
// If we switch from a header, we are looking for the implementation
// file, so we use the definition loc; otherwise we look for the header file,
// we use the decl loc;
// For each symbol in the original file, we get its target location (decl or
// def) from the index, then award that target file.
bool IsHeader = isHeaderFile(OriginalFile, AST.getLangOpts());
Index->lookup(Request, [&](const Symbol &Sym) {
if (IsHeader)
// FIXME: our index doesn't have any interesting information (this could be
// that the background-index is not finished), we should use the decl/def
// locations from the AST to do the inference (from .cc to .h).
if (Candidates.empty())
return None;
// Pickup the winner, who contains most of symbols.
// FIXME: should we use other signals (file proximity) to help score?
auto Best = Candidates.begin();
for (auto It = Candidates.begin(); It != Candidates.end(); ++It) {
if (It->second > Best->second)
Best = It;
else if (It->second == Best->second && It->first() < Best->first())
// Select the first one in the lexical order if we have multiple
// candidates.
Best = It;
return Path(Best->first());
std::vector<const Decl *> getIndexableLocalDecls(ParsedAST &AST) {
std::vector<const Decl *> Results;
std::function<void(Decl *)> TraverseDecl = [&](Decl *D) {
auto *ND = llvm::dyn_cast<NamedDecl>(D);
if (!ND || ND->isImplicit())
if (!SymbolCollector::shouldCollectSymbol(*ND, D->getASTContext(), {},
if (!llvm::isa<FunctionDecl>(ND)) {
// Visit the children, but we skip function decls as we are not interested
// in the function body.
if (auto *Scope = llvm::dyn_cast<DeclContext>(ND)) {
for (auto *D : Scope->decls())
if (llvm::isa<NamespaceDecl>(D))
return; // namespace is indexable, but we're not interested.
// Traverses the ParsedAST directly to collect all decls present in the main
// file.
for (auto *TopLevel : AST.getLocalTopLevelDecls())
return Results;
} // namespace clangd
} // namespace clang