llvm-project/clang-tools-extra/clangd/index/Merge.cpp

131 lines
4.7 KiB
C++

//===--- Merge.h ------------------------------------------------*- C++-*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===---------------------------------------------------------------------===//
#include "Merge.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/raw_ostream.h"
namespace clang {
namespace clangd {
namespace {
using namespace llvm;
class MergedIndex : public SymbolIndex {
public:
MergedIndex(const SymbolIndex *Dynamic, const SymbolIndex *Static)
: Dynamic(Dynamic), Static(Static) {}
// FIXME: Deleted symbols in dirty files are still returned (from Static).
// To identify these eliminate these, we should:
// - find the generating file from each Symbol which is Static-only
// - ask Dynamic if it has that file (needs new SymbolIndex method)
// - if so, drop the Symbol.
bool fuzzyFind(const FuzzyFindRequest &Req,
function_ref<void(const Symbol &)> Callback) const override {
// We can't step through both sources in parallel. So:
// 1) query all dynamic symbols, slurping results into a slab
// 2) query the static symbols, for each one:
// a) if it's not in the dynamic slab, yield it directly
// b) if it's in the dynamic slab, merge it and yield the result
// 3) now yield all the dynamic symbols we haven't processed.
bool More = false; // We'll be incomplete if either source was.
SymbolSlab::Builder DynB;
More |= Dynamic->fuzzyFind(Req, [&](const Symbol &S) { DynB.insert(S); });
SymbolSlab Dyn = std::move(DynB).build();
DenseSet<SymbolID> SeenDynamicSymbols;
Symbol::Details Scratch;
More |= Static->fuzzyFind(Req, [&](const Symbol &S) {
auto DynS = Dyn.find(S.ID);
if (DynS == Dyn.end())
return Callback(S);
SeenDynamicSymbols.insert(S.ID);
Callback(mergeSymbol(*DynS, S, &Scratch));
});
for (const Symbol &S : Dyn)
if (!SeenDynamicSymbols.count(S.ID))
Callback(S);
return More;
}
void
lookup(const LookupRequest &Req,
llvm::function_ref<void(const Symbol &)> Callback) const override {
SymbolSlab::Builder B;
Dynamic->lookup(Req, [&](const Symbol &S) { B.insert(S); });
auto RemainingIDs = Req.IDs;
Symbol::Details Scratch;
Static->lookup(Req, [&](const Symbol &S) {
const Symbol *Sym = B.find(S.ID);
RemainingIDs.erase(S.ID);
if (!Sym)
Callback(S);
else
Callback(mergeSymbol(*Sym, S, &Scratch));
});
for (const auto &ID : RemainingIDs)
if (const Symbol *Sym = B.find(ID))
Callback(*Sym);
}
private:
const SymbolIndex *Dynamic, *Static;
};
}
Symbol
mergeSymbol(const Symbol &L, const Symbol &R, Symbol::Details *Scratch) {
assert(L.ID == R.ID);
// We prefer information from TUs that saw the definition.
// Classes: this is the def itself. Functions: hopefully the header decl.
// If both did (or both didn't), continue to prefer L over R.
bool PreferR = R.Definition && !L.Definition;
Symbol S = PreferR ? R : L; // The target symbol we're merging into.
const Symbol &O = PreferR ? L : R; // The "other" less-preferred symbol.
// For each optional field, fill it from O if missing in S.
// (It might be missing in O too, but that's a no-op).
if (!S.Definition)
S.Definition = O.Definition;
if (!S.CanonicalDeclaration)
S.CanonicalDeclaration = O.CanonicalDeclaration;
S.References += O.References;
if (S.CompletionLabel == "")
S.CompletionLabel = O.CompletionLabel;
if (S.CompletionFilterText == "")
S.CompletionFilterText = O.CompletionFilterText;
if (S.CompletionPlainInsertText == "")
S.CompletionPlainInsertText = O.CompletionPlainInsertText;
if (S.CompletionSnippetInsertText == "")
S.CompletionSnippetInsertText = O.CompletionSnippetInsertText;
if (O.Detail) {
if (S.Detail) {
// Copy into scratch space so we can merge.
*Scratch = *S.Detail;
if (Scratch->Documentation == "")
Scratch->Documentation = O.Detail->Documentation;
if (Scratch->CompletionDetail == "")
Scratch->CompletionDetail = O.Detail->CompletionDetail;
if (Scratch->IncludeHeader == "")
Scratch->IncludeHeader = O.Detail->IncludeHeader;
S.Detail = Scratch;
} else
S.Detail = O.Detail;
}
return S;
}
std::unique_ptr<SymbolIndex> mergeIndex(const SymbolIndex *Dynamic,
const SymbolIndex *Static) {
return llvm::make_unique<MergedIndex>(Dynamic, Static);
}
} // namespace clangd
} // namespace clang