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//===--- UsingDeclarationsSorter.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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements UsingDeclarationsSorter, a TokenAnalyzer that
/// sorts consecutive using declarations.
///
//===----------------------------------------------------------------------===//
#include "UsingDeclarationsSorter.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Regex.h"
#include <algorithm>
#define DEBUG_TYPE "using-declarations-sorter"
namespace clang {
namespace format {
namespace {
// The order of using declaration is defined as follows:
// Split the strings by "::" and discard any initial empty strings. The last
// element of each list is a non-namespace name; all others are namespace
// names. Sort the lists of names lexicographically, where the sort order of
// individual names is that all non-namespace names come before all namespace
// names, and within those groups, names are in case-insensitive lexicographic
// order.
int compareLabels(StringRef A, StringRef B) {
SmallVector<StringRef, 2> NamesA;
A.split(NamesA, "::", /*MaxSplit=*/-1, /*KeepEmpty=*/false);
SmallVector<StringRef, 2> NamesB;
B.split(NamesB, "::", /*MaxSplit=*/-1, /*KeepEmpty=*/false);
size_t SizeA = NamesA.size();
size_t SizeB = NamesB.size();
for (size_t I = 0, E = std::min(SizeA, SizeB); I < E; ++I) {
if (I + 1 == SizeA) {
// I is the last index of NamesA and NamesA[I] is a non-namespace name.
// Non-namespace names come before all namespace names.
if (SizeB > SizeA)
return -1;
// Two names within a group compare case-insensitively.
return NamesA[I].compare_lower(NamesB[I]);
}
// I is the last index of NamesB and NamesB[I] is a non-namespace name.
// Non-namespace names come before all namespace names.
if (I + 1 == SizeB)
return 1;
// Two namespaces names within a group compare case-insensitively.
int C = NamesA[I].compare_lower(NamesB[I]);
if (C != 0)
return C;
}
return 0;
}
struct UsingDeclaration {
const AnnotatedLine *Line;
std::string Label;
UsingDeclaration(const AnnotatedLine *Line, const std::string &Label)
: Line(Line), Label(Label) {}
bool operator<(const UsingDeclaration &Other) const {
return compareLabels(Label, Other.Label) < 0;
}
};
/// Computes the label of a using declaration starting at tthe using token
/// \p UsingTok.
/// If \p UsingTok doesn't begin a using declaration, returns the empty string.
/// Note that this detects specifically using declarations, as in:
/// using A::B::C;
/// and not type aliases, as in:
/// using A = B::C;
/// Type aliases are in general not safe to permute.
std::string computeUsingDeclarationLabel(const FormatToken *UsingTok) {
assert(UsingTok && UsingTok->is(tok::kw_using) && "Expecting a using token");
std::string Label;
const FormatToken *Tok = UsingTok->Next;
if (Tok && Tok->is(tok::kw_typename)) {
Label.append("typename ");
Tok = Tok->Next;
}
if (Tok && Tok->is(tok::coloncolon)) {
Label.append("::");
Tok = Tok->Next;
}
bool HasIdentifier = false;
while (Tok && Tok->is(tok::identifier)) {
HasIdentifier = true;
Label.append(Tok->TokenText.str());
Tok = Tok->Next;
if (!Tok || Tok->isNot(tok::coloncolon))
break;
Label.append("::");
Tok = Tok->Next;
}
if (HasIdentifier && Tok && Tok->isOneOf(tok::semi, tok::comma))
return Label;
return "";
}
void endUsingDeclarationBlock(
SmallVectorImpl<UsingDeclaration> *UsingDeclarations,
const SourceManager &SourceMgr, tooling::Replacements *Fixes) {
bool BlockAffected = false;
for (const UsingDeclaration &Declaration : *UsingDeclarations) {
if (Declaration.Line->Affected) {
BlockAffected = true;
break;
}
}
if (!BlockAffected) {
UsingDeclarations->clear();
return;
}
SmallVector<UsingDeclaration, 4> SortedUsingDeclarations(
UsingDeclarations->begin(), UsingDeclarations->end());
llvm::stable_sort(SortedUsingDeclarations);
SortedUsingDeclarations.erase(
std::unique(SortedUsingDeclarations.begin(),
SortedUsingDeclarations.end(),
[](const UsingDeclaration &a, const UsingDeclaration &b) {
return a.Label == b.Label;
}),
SortedUsingDeclarations.end());
for (size_t I = 0, E = UsingDeclarations->size(); I < E; ++I) {
if (I >= SortedUsingDeclarations.size()) {
// This using declaration has been deduplicated, delete it.
auto Begin =
(*UsingDeclarations)[I].Line->First->WhitespaceRange.getBegin();
auto End = (*UsingDeclarations)[I].Line->Last->Tok.getEndLoc();
auto Range = CharSourceRange::getCharRange(Begin, End);
auto Err = Fixes->add(tooling::Replacement(SourceMgr, Range, ""));
if (Err) {
llvm::errs() << "Error while sorting using declarations: "
<< llvm::toString(std::move(Err)) << "\n";
}
continue;
}
if ((*UsingDeclarations)[I].Line == SortedUsingDeclarations[I].Line)
continue;
auto Begin = (*UsingDeclarations)[I].Line->First->Tok.getLocation();
auto End = (*UsingDeclarations)[I].Line->Last->Tok.getEndLoc();
auto SortedBegin =
SortedUsingDeclarations[I].Line->First->Tok.getLocation();
auto SortedEnd = SortedUsingDeclarations[I].Line->Last->Tok.getEndLoc();
StringRef Text(SourceMgr.getCharacterData(SortedBegin),
SourceMgr.getCharacterData(SortedEnd) -
SourceMgr.getCharacterData(SortedBegin));
LLVM_DEBUG({
StringRef OldText(SourceMgr.getCharacterData(Begin),
SourceMgr.getCharacterData(End) -
SourceMgr.getCharacterData(Begin));
llvm::dbgs() << "Replacing '" << OldText << "' with '" << Text << "'\n";
});
auto Range = CharSourceRange::getCharRange(Begin, End);
auto Err = Fixes->add(tooling::Replacement(SourceMgr, Range, Text));
if (Err) {
llvm::errs() << "Error while sorting using declarations: "
<< llvm::toString(std::move(Err)) << "\n";
}
}
UsingDeclarations->clear();
}
} // namespace
UsingDeclarationsSorter::UsingDeclarationsSorter(const Environment &Env,
const FormatStyle &Style)
: TokenAnalyzer(Env, Style) {}
std::pair<tooling::Replacements, unsigned> UsingDeclarationsSorter::analyze(
TokenAnnotator &Annotator, SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
FormatTokenLexer &Tokens) {
const SourceManager &SourceMgr = Env.getSourceManager();
AffectedRangeMgr.computeAffectedLines(AnnotatedLines);
tooling::Replacements Fixes;
SmallVector<UsingDeclaration, 4> UsingDeclarations;
for (size_t I = 0, E = AnnotatedLines.size(); I != E; ++I) {
const auto *FirstTok = AnnotatedLines[I]->First;
if (AnnotatedLines[I]->InPPDirective ||
!AnnotatedLines[I]->startsWith(tok::kw_using) || FirstTok->Finalized) {
endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
continue;
}
if (FirstTok->NewlinesBefore > 1)
endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
const auto *UsingTok =
FirstTok->is(tok::comment) ? FirstTok->getNextNonComment() : FirstTok;
std::string Label = computeUsingDeclarationLabel(UsingTok);
if (Label.empty()) {
endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
continue;
}
UsingDeclarations.push_back(UsingDeclaration(AnnotatedLines[I], Label));
}
endUsingDeclarationBlock(&UsingDeclarations, SourceMgr, &Fixes);
return {Fixes, 0};
}
} // namespace format
} // namespace clang