llvm-project/clang/lib/Format/NamespaceEndCommentsFixer.cpp

300 lines
12 KiB
C++

//===--- NamespaceEndCommentsFixer.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 NamespaceEndCommentsFixer, a TokenAnalyzer that
/// fixes namespace end comments.
///
//===----------------------------------------------------------------------===//
#include "NamespaceEndCommentsFixer.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Regex.h"
#define DEBUG_TYPE "namespace-end-comments-fixer"
namespace clang {
namespace format {
namespace {
// The maximal number of unwrapped lines that a short namespace spans.
// Short namespaces don't need an end comment.
static const int kShortNamespaceMaxLines = 1;
// Computes the name of a namespace given the namespace token.
// Returns "" for anonymous namespace.
std::string computeName(const FormatToken *NamespaceTok) {
assert(NamespaceTok &&
NamespaceTok->isOneOf(tok::kw_namespace, TT_NamespaceMacro) &&
"expecting a namespace token");
std::string name = "";
const FormatToken *Tok = NamespaceTok->getNextNonComment();
if (NamespaceTok->is(TT_NamespaceMacro)) {
// Collects all the non-comment tokens between opening parenthesis
// and closing parenthesis or comma.
assert(Tok && Tok->is(tok::l_paren) && "expected an opening parenthesis");
Tok = Tok->getNextNonComment();
while (Tok && !Tok->isOneOf(tok::r_paren, tok::comma)) {
name += Tok->TokenText;
Tok = Tok->getNextNonComment();
}
} else {
// For `namespace [[foo]] A::B::inline C {` or
// `namespace MACRO1 MACRO2 A::B::inline C {`, returns "A::B::inline C".
// Peek for the first '::' (or '{') and then return all tokens from one
// token before that up until the '{'.
const FormatToken *FirstNSTok = Tok;
while (Tok && !Tok->is(tok::l_brace) && !Tok->is(tok::coloncolon)) {
FirstNSTok = Tok;
Tok = Tok->getNextNonComment();
}
Tok = FirstNSTok;
while (Tok && !Tok->is(tok::l_brace)) {
name += Tok->TokenText;
if (Tok->is(tok::kw_inline))
name += " ";
Tok = Tok->getNextNonComment();
}
}
return name;
}
std::string computeEndCommentText(StringRef NamespaceName, bool AddNewline,
const FormatToken *NamespaceTok,
unsigned SpacesToAdd) {
std::string text = "//";
text.append(SpacesToAdd, ' ');
text += NamespaceTok->TokenText;
if (NamespaceTok->is(TT_NamespaceMacro))
text += "(";
else if (!NamespaceName.empty())
text += ' ';
text += NamespaceName;
if (NamespaceTok->is(TT_NamespaceMacro))
text += ")";
if (AddNewline)
text += '\n';
return text;
}
bool hasEndComment(const FormatToken *RBraceTok) {
return RBraceTok->Next && RBraceTok->Next->is(tok::comment);
}
bool validEndComment(const FormatToken *RBraceTok, StringRef NamespaceName,
const FormatToken *NamespaceTok) {
assert(hasEndComment(RBraceTok));
const FormatToken *Comment = RBraceTok->Next;
// Matches a valid namespace end comment.
// Valid namespace end comments don't need to be edited.
static const llvm::Regex NamespaceCommentPattern =
llvm::Regex("^/[/*] *(end (of )?)? *(anonymous|unnamed)? *"
"namespace( +([a-zA-Z0-9:_]+))?\\.? *(\\*/)?$",
llvm::Regex::IgnoreCase);
static const llvm::Regex NamespaceMacroCommentPattern =
llvm::Regex("^/[/*] *(end (of )?)? *(anonymous|unnamed)? *"
"([a-zA-Z0-9_]+)\\(([a-zA-Z0-9:_]*)\\)\\.? *(\\*/)?$",
llvm::Regex::IgnoreCase);
SmallVector<StringRef, 8> Groups;
if (NamespaceTok->is(TT_NamespaceMacro) &&
NamespaceMacroCommentPattern.match(Comment->TokenText, &Groups)) {
StringRef NamespaceTokenText = Groups.size() > 4 ? Groups[4] : "";
// The name of the macro must be used.
if (NamespaceTokenText != NamespaceTok->TokenText)
return false;
} else if (NamespaceTok->isNot(tok::kw_namespace) ||
!NamespaceCommentPattern.match(Comment->TokenText, &Groups)) {
// Comment does not match regex.
return false;
}
StringRef NamespaceNameInComment = Groups.size() > 5 ? Groups[5] : "";
// Anonymous namespace comments must not mention a namespace name.
if (NamespaceName.empty() && !NamespaceNameInComment.empty())
return false;
StringRef AnonymousInComment = Groups.size() > 3 ? Groups[3] : "";
// Named namespace comments must not mention anonymous namespace.
if (!NamespaceName.empty() && !AnonymousInComment.empty())
return false;
if (NamespaceNameInComment == NamespaceName)
return true;
// Has namespace comment flowed onto the next line.
// } // namespace
// // verylongnamespacenamethatdidnotfitonthepreviouscommentline
if (!(Comment->Next && Comment->Next->is(TT_LineComment)))
return false;
static const llvm::Regex CommentPattern = llvm::Regex(
"^/[/*] *( +([a-zA-Z0-9:_]+))?\\.? *(\\*/)?$", llvm::Regex::IgnoreCase);
// Pull out just the comment text.
if (!CommentPattern.match(Comment->Next->TokenText, &Groups)) {
return false;
}
NamespaceNameInComment = Groups.size() > 2 ? Groups[2] : "";
return (NamespaceNameInComment == NamespaceName);
}
void addEndComment(const FormatToken *RBraceTok, StringRef EndCommentText,
const SourceManager &SourceMgr,
tooling::Replacements *Fixes) {
auto EndLoc = RBraceTok->Tok.getEndLoc();
auto Range = CharSourceRange::getCharRange(EndLoc, EndLoc);
auto Err = Fixes->add(tooling::Replacement(SourceMgr, Range, EndCommentText));
if (Err) {
llvm::errs() << "Error while adding namespace end comment: "
<< llvm::toString(std::move(Err)) << "\n";
}
}
void updateEndComment(const FormatToken *RBraceTok, StringRef EndCommentText,
const SourceManager &SourceMgr,
tooling::Replacements *Fixes) {
assert(hasEndComment(RBraceTok));
const FormatToken *Comment = RBraceTok->Next;
auto Range = CharSourceRange::getCharRange(Comment->getStartOfNonWhitespace(),
Comment->Tok.getEndLoc());
auto Err = Fixes->add(tooling::Replacement(SourceMgr, Range, EndCommentText));
if (Err) {
llvm::errs() << "Error while updating namespace end comment: "
<< llvm::toString(std::move(Err)) << "\n";
}
}
} // namespace
const FormatToken *
getNamespaceToken(const AnnotatedLine *Line,
const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
if (!Line->Affected || Line->InPPDirective || !Line->startsWith(tok::r_brace))
return nullptr;
size_t StartLineIndex = Line->MatchingOpeningBlockLineIndex;
if (StartLineIndex == UnwrappedLine::kInvalidIndex)
return nullptr;
assert(StartLineIndex < AnnotatedLines.size());
const FormatToken *NamespaceTok = AnnotatedLines[StartLineIndex]->First;
if (NamespaceTok->is(tok::l_brace)) {
// "namespace" keyword can be on the line preceding '{', e.g. in styles
// where BraceWrapping.AfterNamespace is true.
if (StartLineIndex > 0)
NamespaceTok = AnnotatedLines[StartLineIndex - 1]->First;
}
return NamespaceTok->getNamespaceToken();
}
StringRef
getNamespaceTokenText(const AnnotatedLine *Line,
const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
const FormatToken *NamespaceTok = getNamespaceToken(Line, AnnotatedLines);
return NamespaceTok ? NamespaceTok->TokenText : StringRef();
}
NamespaceEndCommentsFixer::NamespaceEndCommentsFixer(const Environment &Env,
const FormatStyle &Style)
: TokenAnalyzer(Env, Style) {}
std::pair<tooling::Replacements, unsigned> NamespaceEndCommentsFixer::analyze(
TokenAnnotator &Annotator, SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
FormatTokenLexer &Tokens) {
const SourceManager &SourceMgr = Env.getSourceManager();
AffectedRangeMgr.computeAffectedLines(AnnotatedLines);
tooling::Replacements Fixes;
// Spin through the lines and ensure we have balanced braces.
int Braces = 0;
for (size_t I = 0, E = AnnotatedLines.size(); I != E; ++I) {
FormatToken *Tok = AnnotatedLines[I]->First;
while (Tok) {
Braces += Tok->is(tok::l_brace) ? 1 : Tok->is(tok::r_brace) ? -1 : 0;
Tok = Tok->Next;
}
}
// Don't attempt to comment unbalanced braces or this can
// lead to comments being placed on the closing brace which isn't
// the matching brace of the namespace. (occurs during incomplete editing).
if (Braces != 0) {
return {Fixes, 0};
}
std::string AllNamespaceNames = "";
size_t StartLineIndex = SIZE_MAX;
StringRef NamespaceTokenText;
unsigned int CompactedNamespacesCount = 0;
for (size_t I = 0, E = AnnotatedLines.size(); I != E; ++I) {
const AnnotatedLine *EndLine = AnnotatedLines[I];
const FormatToken *NamespaceTok =
getNamespaceToken(EndLine, AnnotatedLines);
if (!NamespaceTok)
continue;
FormatToken *RBraceTok = EndLine->First;
if (RBraceTok->Finalized)
continue;
RBraceTok->Finalized = true;
const FormatToken *EndCommentPrevTok = RBraceTok;
// Namespaces often end with '};'. In that case, attach namespace end
// comments to the semicolon tokens.
if (RBraceTok->Next && RBraceTok->Next->is(tok::semi)) {
EndCommentPrevTok = RBraceTok->Next;
}
if (StartLineIndex == SIZE_MAX)
StartLineIndex = EndLine->MatchingOpeningBlockLineIndex;
std::string NamespaceName = computeName(NamespaceTok);
if (Style.CompactNamespaces) {
if (CompactedNamespacesCount == 0)
NamespaceTokenText = NamespaceTok->TokenText;
if ((I + 1 < E) &&
NamespaceTokenText ==
getNamespaceTokenText(AnnotatedLines[I + 1], AnnotatedLines) &&
StartLineIndex - CompactedNamespacesCount - 1 ==
AnnotatedLines[I + 1]->MatchingOpeningBlockLineIndex &&
!AnnotatedLines[I + 1]->First->Finalized) {
if (hasEndComment(EndCommentPrevTok)) {
// remove end comment, it will be merged in next one
updateEndComment(EndCommentPrevTok, std::string(), SourceMgr, &Fixes);
}
CompactedNamespacesCount++;
AllNamespaceNames = "::" + NamespaceName + AllNamespaceNames;
continue;
}
NamespaceName += AllNamespaceNames;
CompactedNamespacesCount = 0;
AllNamespaceNames = std::string();
}
// The next token in the token stream after the place where the end comment
// token must be. This is either the next token on the current line or the
// first token on the next line.
const FormatToken *EndCommentNextTok = EndCommentPrevTok->Next;
if (EndCommentNextTok && EndCommentNextTok->is(tok::comment))
EndCommentNextTok = EndCommentNextTok->Next;
if (!EndCommentNextTok && I + 1 < E)
EndCommentNextTok = AnnotatedLines[I + 1]->First;
bool AddNewline = EndCommentNextTok &&
EndCommentNextTok->NewlinesBefore == 0 &&
EndCommentNextTok->isNot(tok::eof);
const std::string EndCommentText =
computeEndCommentText(NamespaceName, AddNewline, NamespaceTok,
Style.SpacesInLineCommentPrefix.Minimum);
if (!hasEndComment(EndCommentPrevTok)) {
bool isShort = I - StartLineIndex <= kShortNamespaceMaxLines + 1;
if (!isShort)
addEndComment(EndCommentPrevTok, EndCommentText, SourceMgr, &Fixes);
} else if (!validEndComment(EndCommentPrevTok, NamespaceName,
NamespaceTok)) {
updateEndComment(EndCommentPrevTok, EndCommentText, SourceMgr, &Fixes);
}
StartLineIndex = SIZE_MAX;
}
return {Fixes, 0};
}
} // namespace format
} // namespace clang