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//===--- FormatTokenLexer.cpp - Lex FormatTokens -------------*- 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 FormatTokenLexer, which tokenizes a source file
/// into a FormatToken stream suitable for ClangFormat.
///
//===----------------------------------------------------------------------===//
#include "FormatTokenLexer.h"
#include "FormatToken.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Format/Format.h"
#include "llvm/Support/Regex.h"
namespace clang {
namespace format {
FormatTokenLexer::FormatTokenLexer(
const SourceManager &SourceMgr, FileID ID, unsigned Column,
const FormatStyle &Style, encoding::Encoding Encoding,
llvm::SpecificBumpPtrAllocator<FormatToken> &Allocator,
IdentifierTable &IdentTable)
: FormatTok(nullptr), IsFirstToken(true), StateStack({LexerState::NORMAL}),
Column(Column), TrailingWhitespace(0),
LangOpts(getFormattingLangOpts(Style)), SourceMgr(SourceMgr), ID(ID),
Style(Style), IdentTable(IdentTable), Keywords(IdentTable),
Encoding(Encoding), Allocator(Allocator), FirstInLineIndex(0),
FormattingDisabled(false), MacroBlockBeginRegex(Style.MacroBlockBegin),
MacroBlockEndRegex(Style.MacroBlockEnd) {
Lex.reset(new Lexer(ID, SourceMgr.getBufferOrFake(ID), SourceMgr, LangOpts));
Lex->SetKeepWhitespaceMode(true);
for (const std::string &ForEachMacro : Style.ForEachMacros) {
auto Identifier = &IdentTable.get(ForEachMacro);
Macros.insert({Identifier, TT_ForEachMacro});
}
for (const std::string &IfMacro : Style.IfMacros) {
auto Identifier = &IdentTable.get(IfMacro);
Macros.insert({Identifier, TT_IfMacro});
}
for (const std::string &AttributeMacro : Style.AttributeMacros) {
auto Identifier = &IdentTable.get(AttributeMacro);
Macros.insert({Identifier, TT_AttributeMacro});
}
for (const std::string &StatementMacro : Style.StatementMacros) {
auto Identifier = &IdentTable.get(StatementMacro);
Macros.insert({Identifier, TT_StatementMacro});
}
for (const std::string &TypenameMacro : Style.TypenameMacros) {
auto Identifier = &IdentTable.get(TypenameMacro);
Macros.insert({Identifier, TT_TypenameMacro});
}
for (const std::string &NamespaceMacro : Style.NamespaceMacros) {
auto Identifier = &IdentTable.get(NamespaceMacro);
Macros.insert({Identifier, TT_NamespaceMacro});
}
for (const std::string &WhitespaceSensitiveMacro :
Style.WhitespaceSensitiveMacros) {
auto Identifier = &IdentTable.get(WhitespaceSensitiveMacro);
Macros.insert({Identifier, TT_UntouchableMacroFunc});
}
for (const std::string &StatementAttributeLikeMacro :
Style.StatementAttributeLikeMacros) {
auto Identifier = &IdentTable.get(StatementAttributeLikeMacro);
Macros.insert({Identifier, TT_StatementAttributeLikeMacro});
}
}
ArrayRef<FormatToken *> FormatTokenLexer::lex() {
assert(Tokens.empty());
assert(FirstInLineIndex == 0);
do {
Tokens.push_back(getNextToken());
if (Style.isJavaScript()) {
tryParseJSRegexLiteral();
handleTemplateStrings();
}
if (Style.Language == FormatStyle::LK_TextProto)
tryParsePythonComment();
tryMergePreviousTokens();
if (Style.isCSharp()) {
// This needs to come after tokens have been merged so that C#
// string literals are correctly identified.
handleCSharpVerbatimAndInterpolatedStrings();
}
if (Tokens.back()->NewlinesBefore > 0 || Tokens.back()->IsMultiline)
FirstInLineIndex = Tokens.size() - 1;
} while (Tokens.back()->isNot(tok::eof));
return Tokens;
}
void FormatTokenLexer::tryMergePreviousTokens() {
if (tryMerge_TMacro())
return;
if (tryMergeConflictMarkers())
return;
if (tryMergeLessLess())
return;
if (tryMergeForEach())
return;
if (Style.isCpp() && tryTransformTryUsageForC())
return;
if (Style.isJavaScript() || Style.isCSharp()) {
static const tok::TokenKind NullishCoalescingOperator[] = {tok::question,
tok::question};
static const tok::TokenKind NullPropagatingOperator[] = {tok::question,
tok::period};
static const tok::TokenKind FatArrow[] = {tok::equal, tok::greater};
if (tryMergeTokens(FatArrow, TT_FatArrow))
return;
if (tryMergeTokens(NullishCoalescingOperator, TT_NullCoalescingOperator)) {
// Treat like the "||" operator (as opposed to the ternary ?).
Tokens.back()->Tok.setKind(tok::pipepipe);
return;
}
if (tryMergeTokens(NullPropagatingOperator, TT_NullPropagatingOperator)) {
// Treat like a regular "." access.
Tokens.back()->Tok.setKind(tok::period);
return;
}
if (tryMergeNullishCoalescingEqual())
return;
}
if (Style.isCSharp()) {
static const tok::TokenKind CSharpNullConditionalLSquare[] = {
tok::question, tok::l_square};
if (tryMergeCSharpKeywordVariables())
return;
if (tryMergeCSharpStringLiteral())
return;
if (tryTransformCSharpForEach())
return;
if (tryMergeTokens(CSharpNullConditionalLSquare,
TT_CSharpNullConditionalLSquare)) {
// Treat like a regular "[" operator.
Tokens.back()->Tok.setKind(tok::l_square);
return;
}
}
if (tryMergeNSStringLiteral())
return;
if (Style.isJavaScript()) {
static const tok::TokenKind JSIdentity[] = {tok::equalequal, tok::equal};
static const tok::TokenKind JSNotIdentity[] = {tok::exclaimequal,
tok::equal};
static const tok::TokenKind JSShiftEqual[] = {tok::greater, tok::greater,
tok::greaterequal};
static const tok::TokenKind JSExponentiation[] = {tok::star, tok::star};
static const tok::TokenKind JSExponentiationEqual[] = {tok::star,
tok::starequal};
static const tok::TokenKind JSPipePipeEqual[] = {tok::pipepipe, tok::equal};
static const tok::TokenKind JSAndAndEqual[] = {tok::ampamp, tok::equal};
// FIXME: Investigate what token type gives the correct operator priority.
if (tryMergeTokens(JSIdentity, TT_BinaryOperator))
return;
if (tryMergeTokens(JSNotIdentity, TT_BinaryOperator))
return;
if (tryMergeTokens(JSShiftEqual, TT_BinaryOperator))
return;
if (tryMergeTokens(JSExponentiation, TT_JsExponentiation))
return;
if (tryMergeTokens(JSExponentiationEqual, TT_JsExponentiationEqual)) {
Tokens.back()->Tok.setKind(tok::starequal);
return;
}
if (tryMergeTokens(JSAndAndEqual, TT_JsAndAndEqual) ||
tryMergeTokens(JSPipePipeEqual, TT_JsPipePipeEqual)) {
// Treat like the "=" assignment operator.
Tokens.back()->Tok.setKind(tok::equal);
return;
}
if (tryMergeJSPrivateIdentifier())
return;
}
if (Style.Language == FormatStyle::LK_Java) {
static const tok::TokenKind JavaRightLogicalShiftAssign[] = {
tok::greater, tok::greater, tok::greaterequal};
if (tryMergeTokens(JavaRightLogicalShiftAssign, TT_BinaryOperator))
return;
}
}
bool FormatTokenLexer::tryMergeNSStringLiteral() {
if (Tokens.size() < 2)
return false;
auto &At = *(Tokens.end() - 2);
auto &String = *(Tokens.end() - 1);
if (!At->is(tok::at) || !String->is(tok::string_literal))
return false;
At->Tok.setKind(tok::string_literal);
At->TokenText = StringRef(At->TokenText.begin(),
String->TokenText.end() - At->TokenText.begin());
At->ColumnWidth += String->ColumnWidth;
At->setType(TT_ObjCStringLiteral);
Tokens.erase(Tokens.end() - 1);
return true;
}
bool FormatTokenLexer::tryMergeJSPrivateIdentifier() {
// Merges #idenfier into a single identifier with the text #identifier
// but the token tok::identifier.
if (Tokens.size() < 2)
return false;
auto &Hash = *(Tokens.end() - 2);
auto &Identifier = *(Tokens.end() - 1);
if (!Hash->is(tok::hash) || !Identifier->is(tok::identifier))
return false;
Hash->Tok.setKind(tok::identifier);
Hash->TokenText =
StringRef(Hash->TokenText.begin(),
Identifier->TokenText.end() - Hash->TokenText.begin());
Hash->ColumnWidth += Identifier->ColumnWidth;
Hash->setType(TT_JsPrivateIdentifier);
Tokens.erase(Tokens.end() - 1);
return true;
}
// Search for verbatim or interpolated string literals @"ABC" or
// $"aaaaa{abc}aaaaa" i and mark the token as TT_CSharpStringLiteral, and to
// prevent splitting of @, $ and ".
// Merging of multiline verbatim strings with embedded '"' is handled in
// handleCSharpVerbatimAndInterpolatedStrings with lower-level lexing.
bool FormatTokenLexer::tryMergeCSharpStringLiteral() {
if (Tokens.size() < 2)
return false;
// Interpolated strings could contain { } with " characters inside.
// $"{x ?? "null"}"
// should not be split into $"{x ?? ", null, "}" but should treated as a
// single string-literal.
//
// We opt not to try and format expressions inside {} within a C#
// interpolated string. Formatting expressions within an interpolated string
// would require similar work as that done for JavaScript template strings
// in `handleTemplateStrings()`.
auto &CSharpInterpolatedString = *(Tokens.end() - 2);
if (CSharpInterpolatedString->getType() == TT_CSharpStringLiteral &&
(CSharpInterpolatedString->TokenText.startswith(R"($")") ||
CSharpInterpolatedString->TokenText.startswith(R"($@")"))) {
int UnmatchedOpeningBraceCount = 0;
auto TokenTextSize = CSharpInterpolatedString->TokenText.size();
for (size_t Index = 0; Index < TokenTextSize; ++Index) {
char C = CSharpInterpolatedString->TokenText[Index];
if (C == '{') {
// "{{" inside an interpolated string is an escaped '{' so skip it.
if (Index + 1 < TokenTextSize &&
CSharpInterpolatedString->TokenText[Index + 1] == '{') {
++Index;
continue;
}
++UnmatchedOpeningBraceCount;
} else if (C == '}') {
// "}}" inside an interpolated string is an escaped '}' so skip it.
if (Index + 1 < TokenTextSize &&
CSharpInterpolatedString->TokenText[Index + 1] == '}') {
++Index;
continue;
}
--UnmatchedOpeningBraceCount;
}
}
if (UnmatchedOpeningBraceCount > 0) {
auto &NextToken = *(Tokens.end() - 1);
CSharpInterpolatedString->TokenText =
StringRef(CSharpInterpolatedString->TokenText.begin(),
NextToken->TokenText.end() -
CSharpInterpolatedString->TokenText.begin());
CSharpInterpolatedString->ColumnWidth += NextToken->ColumnWidth;
Tokens.erase(Tokens.end() - 1);
return true;
}
}
// Look for @"aaaaaa" or $"aaaaaa".
auto &String = *(Tokens.end() - 1);
if (!String->is(tok::string_literal))
return false;
auto &At = *(Tokens.end() - 2);
if (!(At->is(tok::at) || At->TokenText == "$"))
return false;
if (Tokens.size() > 2 && At->is(tok::at)) {
auto &Dollar = *(Tokens.end() - 3);
if (Dollar->TokenText == "$") {
// This looks like $@"aaaaa" so we need to combine all 3 tokens.
Dollar->Tok.setKind(tok::string_literal);
Dollar->TokenText =
StringRef(Dollar->TokenText.begin(),
String->TokenText.end() - Dollar->TokenText.begin());
Dollar->ColumnWidth += (At->ColumnWidth + String->ColumnWidth);
Dollar->setType(TT_CSharpStringLiteral);
Tokens.erase(Tokens.end() - 2);
Tokens.erase(Tokens.end() - 1);
return true;
}
}
// Convert back into just a string_literal.
At->Tok.setKind(tok::string_literal);
At->TokenText = StringRef(At->TokenText.begin(),
String->TokenText.end() - At->TokenText.begin());
At->ColumnWidth += String->ColumnWidth;
At->setType(TT_CSharpStringLiteral);
Tokens.erase(Tokens.end() - 1);
return true;
}
// Valid C# attribute targets:
// https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/attributes/#attribute-targets
const llvm::StringSet<> FormatTokenLexer::CSharpAttributeTargets = {
"assembly", "module", "field", "event", "method",
"param", "property", "return", "type",
};
bool FormatTokenLexer::tryMergeNullishCoalescingEqual() {
if (Tokens.size() < 2)
return false;
auto &NullishCoalescing = *(Tokens.end() - 2);
auto &Equal = *(Tokens.end() - 1);
if (NullishCoalescing->getType() != TT_NullCoalescingOperator ||
!Equal->is(tok::equal)) {
return false;
}
NullishCoalescing->Tok.setKind(tok::equal); // no '??=' in clang tokens.
NullishCoalescing->TokenText =
StringRef(NullishCoalescing->TokenText.begin(),
Equal->TokenText.end() - NullishCoalescing->TokenText.begin());
NullishCoalescing->ColumnWidth += Equal->ColumnWidth;
NullishCoalescing->setType(TT_NullCoalescingEqual);
Tokens.erase(Tokens.end() - 1);
return true;
}
bool FormatTokenLexer::tryMergeCSharpKeywordVariables() {
if (Tokens.size() < 2)
return false;
auto &At = *(Tokens.end() - 2);
auto &Keyword = *(Tokens.end() - 1);
if (!At->is(tok::at))
return false;
if (!Keywords.isCSharpKeyword(*Keyword))
return false;
At->Tok.setKind(tok::identifier);
At->TokenText = StringRef(At->TokenText.begin(),
Keyword->TokenText.end() - At->TokenText.begin());
At->ColumnWidth += Keyword->ColumnWidth;
At->setType(Keyword->getType());
Tokens.erase(Tokens.end() - 1);
return true;
}
// In C# transform identifier foreach into kw_foreach
bool FormatTokenLexer::tryTransformCSharpForEach() {
if (Tokens.size() < 1)
return false;
auto &Identifier = *(Tokens.end() - 1);
if (!Identifier->is(tok::identifier))
return false;
if (Identifier->TokenText != "foreach")
return false;
Identifier->setType(TT_ForEachMacro);
Identifier->Tok.setKind(tok::kw_for);
return true;
}
bool FormatTokenLexer::tryMergeForEach() {
if (Tokens.size() < 2)
return false;
auto &For = *(Tokens.end() - 2);
auto &Each = *(Tokens.end() - 1);
if (!For->is(tok::kw_for))
return false;
if (!Each->is(tok::identifier))
return false;
if (Each->TokenText != "each")
return false;
For->setType(TT_ForEachMacro);
For->Tok.setKind(tok::kw_for);
For->TokenText = StringRef(For->TokenText.begin(),
Each->TokenText.end() - For->TokenText.begin());
For->ColumnWidth += Each->ColumnWidth;
Tokens.erase(Tokens.end() - 1);
return true;
}
bool FormatTokenLexer::tryTransformTryUsageForC() {
if (Tokens.size() < 2)
return false;
auto &Try = *(Tokens.end() - 2);
if (!Try->is(tok::kw_try))
return false;
auto &Next = *(Tokens.end() - 1);
if (Next->isOneOf(tok::l_brace, tok::colon, tok::hash, tok::comment))
return false;
if (Tokens.size() > 2) {
auto &At = *(Tokens.end() - 3);
if (At->is(tok::at))
return false;
}
Try->Tok.setKind(tok::identifier);
return true;
}
bool FormatTokenLexer::tryMergeLessLess() {
// Merge X,less,less,Y into X,lessless,Y unless X or Y is less.
if (Tokens.size() < 3)
return false;
auto First = Tokens.end() - 3;
if (First[0]->isNot(tok::less) || First[1]->isNot(tok::less))
return false;
// Only merge if there currently is no whitespace between the two "<".
if (First[1]->hasWhitespaceBefore())
return false;
auto X = Tokens.size() > 3 ? First[-1] : nullptr;
auto Y = First[2];
if ((X && X->is(tok::less)) || Y->is(tok::less))
return false;
// Do not remove a whitespace between the two "<" e.g. "operator< <>".
if (X && X->is(tok::kw_operator) && Y->is(tok::greater))
return false;
First[0]->Tok.setKind(tok::lessless);
First[0]->TokenText = "<<";
First[0]->ColumnWidth += 1;
Tokens.erase(Tokens.end() - 2);
return true;
}
bool FormatTokenLexer::tryMergeTokens(ArrayRef<tok::TokenKind> Kinds,
TokenType NewType) {
if (Tokens.size() < Kinds.size())
return false;
SmallVectorImpl<FormatToken *>::const_iterator First =
Tokens.end() - Kinds.size();
if (!First[0]->is(Kinds[0]))
return false;
unsigned AddLength = 0;
for (unsigned i = 1; i < Kinds.size(); ++i) {
if (!First[i]->is(Kinds[i]) || First[i]->hasWhitespaceBefore())
return false;
AddLength += First[i]->TokenText.size();
}
Tokens.resize(Tokens.size() - Kinds.size() + 1);
First[0]->TokenText = StringRef(First[0]->TokenText.data(),
First[0]->TokenText.size() + AddLength);
First[0]->ColumnWidth += AddLength;
First[0]->setType(NewType);
return true;
}
// Returns \c true if \p Tok can only be followed by an operand in JavaScript.
bool FormatTokenLexer::precedesOperand(FormatToken *Tok) {
// NB: This is not entirely correct, as an r_paren can introduce an operand
// location in e.g. `if (foo) /bar/.exec(...);`. That is a rare enough
// corner case to not matter in practice, though.
return Tok->isOneOf(tok::period, tok::l_paren, tok::comma, tok::l_brace,
tok::r_brace, tok::l_square, tok::semi, tok::exclaim,
tok::colon, tok::question, tok::tilde) ||
Tok->isOneOf(tok::kw_return, tok::kw_do, tok::kw_case, tok::kw_throw,
tok::kw_else, tok::kw_new, tok::kw_delete, tok::kw_void,
tok::kw_typeof, Keywords.kw_instanceof, Keywords.kw_in) ||
Tok->isBinaryOperator();
}
bool FormatTokenLexer::canPrecedeRegexLiteral(FormatToken *Prev) {
if (!Prev)
return true;
// Regex literals can only follow after prefix unary operators, not after
// postfix unary operators. If the '++' is followed by a non-operand
// introducing token, the slash here is the operand and not the start of a
// regex.
// `!` is an unary prefix operator, but also a post-fix operator that casts
// away nullability, so the same check applies.
if (Prev->isOneOf(tok::plusplus, tok::minusminus, tok::exclaim))
return Tokens.size() < 3 || precedesOperand(Tokens[Tokens.size() - 3]);
// The previous token must introduce an operand location where regex
// literals can occur.
if (!precedesOperand(Prev))
return false;
return true;
}
// Tries to parse a JavaScript Regex literal starting at the current token,
// if that begins with a slash and is in a location where JavaScript allows
// regex literals. Changes the current token to a regex literal and updates
// its text if successful.
void FormatTokenLexer::tryParseJSRegexLiteral() {
FormatToken *RegexToken = Tokens.back();
if (!RegexToken->isOneOf(tok::slash, tok::slashequal))
return;
FormatToken *Prev = nullptr;
for (FormatToken *FT : llvm::drop_begin(llvm::reverse(Tokens))) {
// NB: Because previous pointers are not initialized yet, this cannot use
// Token.getPreviousNonComment.
if (FT->isNot(tok::comment)) {
Prev = FT;
break;
}
}
if (!canPrecedeRegexLiteral(Prev))
return;
// 'Manually' lex ahead in the current file buffer.
const char *Offset = Lex->getBufferLocation();
const char *RegexBegin = Offset - RegexToken->TokenText.size();
StringRef Buffer = Lex->getBuffer();
bool InCharacterClass = false;
bool HaveClosingSlash = false;
for (; !HaveClosingSlash && Offset != Buffer.end(); ++Offset) {
// Regular expressions are terminated with a '/', which can only be
// escaped using '\' or a character class between '[' and ']'.
// See http://www.ecma-international.org/ecma-262/5.1/#sec-7.8.5.
switch (*Offset) {
case '\\':
// Skip the escaped character.
++Offset;
break;
case '[':
InCharacterClass = true;
break;
case ']':
InCharacterClass = false;
break;
case '/':
if (!InCharacterClass)
HaveClosingSlash = true;
break;
}
}
RegexToken->setType(TT_RegexLiteral);
// Treat regex literals like other string_literals.
RegexToken->Tok.setKind(tok::string_literal);
RegexToken->TokenText = StringRef(RegexBegin, Offset - RegexBegin);
RegexToken->ColumnWidth = RegexToken->TokenText.size();
resetLexer(SourceMgr.getFileOffset(Lex->getSourceLocation(Offset)));
}
void FormatTokenLexer::handleCSharpVerbatimAndInterpolatedStrings() {
FormatToken *CSharpStringLiteral = Tokens.back();
if (CSharpStringLiteral->getType() != TT_CSharpStringLiteral)
return;
// Deal with multiline strings.
if (!(CSharpStringLiteral->TokenText.startswith(R"(@")") ||
CSharpStringLiteral->TokenText.startswith(R"($@")"))) {
return;
}
const char *StrBegin =
Lex->getBufferLocation() - CSharpStringLiteral->TokenText.size();
const char *Offset = StrBegin;
if (CSharpStringLiteral->TokenText.startswith(R"(@")"))
Offset += 2;
else // CSharpStringLiteral->TokenText.startswith(R"($@")")
Offset += 3;
// Look for a terminating '"' in the current file buffer.
// Make no effort to format code within an interpolated or verbatim string.
for (; Offset != Lex->getBuffer().end(); ++Offset) {
if (Offset[0] == '"') {
// "" within a verbatim string is an escaped double quote: skip it.
if (Offset + 1 < Lex->getBuffer().end() && Offset[1] == '"')
++Offset;
else
break;
}
}
// Make no attempt to format code properly if a verbatim string is
// unterminated.
if (Offset == Lex->getBuffer().end())
return;
StringRef LiteralText(StrBegin, Offset - StrBegin + 1);
CSharpStringLiteral->TokenText = LiteralText;
// Adjust width for potentially multiline string literals.
size_t FirstBreak = LiteralText.find('\n');
StringRef FirstLineText = FirstBreak == StringRef::npos
? LiteralText
: LiteralText.substr(0, FirstBreak);
CSharpStringLiteral->ColumnWidth = encoding::columnWidthWithTabs(
FirstLineText, CSharpStringLiteral->OriginalColumn, Style.TabWidth,
Encoding);
size_t LastBreak = LiteralText.rfind('\n');
if (LastBreak != StringRef::npos) {
CSharpStringLiteral->IsMultiline = true;
unsigned StartColumn = 0;
CSharpStringLiteral->LastLineColumnWidth =
encoding::columnWidthWithTabs(LiteralText.substr(LastBreak + 1),
StartColumn, Style.TabWidth, Encoding);
}
SourceLocation loc = Offset < Lex->getBuffer().end()
? Lex->getSourceLocation(Offset + 1)
: SourceMgr.getLocForEndOfFile(ID);
resetLexer(SourceMgr.getFileOffset(loc));
}
void FormatTokenLexer::handleTemplateStrings() {
FormatToken *BacktickToken = Tokens.back();
if (BacktickToken->is(tok::l_brace)) {
StateStack.push(LexerState::NORMAL);
return;
}
if (BacktickToken->is(tok::r_brace)) {
if (StateStack.size() == 1)
return;
StateStack.pop();
if (StateStack.top() != LexerState::TEMPLATE_STRING)
return;
// If back in TEMPLATE_STRING, fallthrough and continue parsing the
} else if (BacktickToken->is(tok::unknown) &&
BacktickToken->TokenText == "`") {
StateStack.push(LexerState::TEMPLATE_STRING);
} else {
return; // Not actually a template
}
// 'Manually' lex ahead in the current file buffer.
const char *Offset = Lex->getBufferLocation();
const char *TmplBegin = Offset - BacktickToken->TokenText.size(); // at "`"
for (; Offset != Lex->getBuffer().end(); ++Offset) {
if (Offset[0] == '`') {
StateStack.pop();
break;
}
if (Offset[0] == '\\') {
++Offset; // Skip the escaped character.
} else if (Offset + 1 < Lex->getBuffer().end() && Offset[0] == '$' &&
Offset[1] == '{') {
// '${' introduces an expression interpolation in the template string.
StateStack.push(LexerState::NORMAL);
++Offset;
break;
}
}
StringRef LiteralText(TmplBegin, Offset - TmplBegin + 1);
BacktickToken->setType(TT_TemplateString);
BacktickToken->Tok.setKind(tok::string_literal);
BacktickToken->TokenText = LiteralText;
// Adjust width for potentially multiline string literals.
size_t FirstBreak = LiteralText.find('\n');
StringRef FirstLineText = FirstBreak == StringRef::npos
? LiteralText
: LiteralText.substr(0, FirstBreak);
BacktickToken->ColumnWidth = encoding::columnWidthWithTabs(
FirstLineText, BacktickToken->OriginalColumn, Style.TabWidth, Encoding);
size_t LastBreak = LiteralText.rfind('\n');
if (LastBreak != StringRef::npos) {
BacktickToken->IsMultiline = true;
unsigned StartColumn = 0; // The template tail spans the entire line.
BacktickToken->LastLineColumnWidth =
encoding::columnWidthWithTabs(LiteralText.substr(LastBreak + 1),
StartColumn, Style.TabWidth, Encoding);
}
SourceLocation loc = Offset < Lex->getBuffer().end()
? Lex->getSourceLocation(Offset + 1)
: SourceMgr.getLocForEndOfFile(ID);
resetLexer(SourceMgr.getFileOffset(loc));
}
void FormatTokenLexer::tryParsePythonComment() {
FormatToken *HashToken = Tokens.back();
if (!HashToken->isOneOf(tok::hash, tok::hashhash))
return;
// Turn the remainder of this line into a comment.
const char *CommentBegin =
Lex->getBufferLocation() - HashToken->TokenText.size(); // at "#"
size_t From = CommentBegin - Lex->getBuffer().begin();
size_t To = Lex->getBuffer().find_first_of('\n', From);
if (To == StringRef::npos)
To = Lex->getBuffer().size();
size_t Len = To - From;
HashToken->setType(TT_LineComment);
HashToken->Tok.setKind(tok::comment);
HashToken->TokenText = Lex->getBuffer().substr(From, Len);
SourceLocation Loc = To < Lex->getBuffer().size()
? Lex->getSourceLocation(CommentBegin + Len)
: SourceMgr.getLocForEndOfFile(ID);
resetLexer(SourceMgr.getFileOffset(Loc));
}
bool FormatTokenLexer::tryMerge_TMacro() {
if (Tokens.size() < 4)
return false;
FormatToken *Last = Tokens.back();
if (!Last->is(tok::r_paren))
return false;
FormatToken *String = Tokens[Tokens.size() - 2];
if (!String->is(tok::string_literal) || String->IsMultiline)
return false;
if (!Tokens[Tokens.size() - 3]->is(tok::l_paren))
return false;
FormatToken *Macro = Tokens[Tokens.size() - 4];
if (Macro->TokenText != "_T")
return false;
const char *Start = Macro->TokenText.data();
const char *End = Last->TokenText.data() + Last->TokenText.size();
String->TokenText = StringRef(Start, End - Start);
String->IsFirst = Macro->IsFirst;
String->LastNewlineOffset = Macro->LastNewlineOffset;
String->WhitespaceRange = Macro->WhitespaceRange;
String->OriginalColumn = Macro->OriginalColumn;
String->ColumnWidth = encoding::columnWidthWithTabs(
String->TokenText, String->OriginalColumn, Style.TabWidth, Encoding);
String->NewlinesBefore = Macro->NewlinesBefore;
String->HasUnescapedNewline = Macro->HasUnescapedNewline;
Tokens.pop_back();
Tokens.pop_back();
Tokens.pop_back();
Tokens.back() = String;
if (FirstInLineIndex >= Tokens.size())
FirstInLineIndex = Tokens.size() - 1;
return true;
}
bool FormatTokenLexer::tryMergeConflictMarkers() {
if (Tokens.back()->NewlinesBefore == 0 && Tokens.back()->isNot(tok::eof))
return false;
// Conflict lines look like:
// <marker> <text from the vcs>
// For example:
// >>>>>>> /file/in/file/system at revision 1234
//
// We merge all tokens in a line that starts with a conflict marker
// into a single token with a special token type that the unwrapped line
// parser will use to correctly rebuild the underlying code.
FileID ID;
// Get the position of the first token in the line.
unsigned FirstInLineOffset;
std::tie(ID, FirstInLineOffset) = SourceMgr.getDecomposedLoc(
Tokens[FirstInLineIndex]->getStartOfNonWhitespace());
StringRef Buffer = SourceMgr.getBufferOrFake(ID).getBuffer();
// Calculate the offset of the start of the current line.
auto LineOffset = Buffer.rfind('\n', FirstInLineOffset);
if (LineOffset == StringRef::npos)
LineOffset = 0;
else
++LineOffset;
auto FirstSpace = Buffer.find_first_of(" \n", LineOffset);
StringRef LineStart;
if (FirstSpace == StringRef::npos)
LineStart = Buffer.substr(LineOffset);
else
LineStart = Buffer.substr(LineOffset, FirstSpace - LineOffset);
TokenType Type = TT_Unknown;
if (LineStart == "<<<<<<<" || LineStart == ">>>>") {
Type = TT_ConflictStart;
} else if (LineStart == "|||||||" || LineStart == "=======" ||
LineStart == "====") {
Type = TT_ConflictAlternative;
} else if (LineStart == ">>>>>>>" || LineStart == "<<<<") {
Type = TT_ConflictEnd;
}
if (Type != TT_Unknown) {
FormatToken *Next = Tokens.back();
Tokens.resize(FirstInLineIndex + 1);
// We do not need to build a complete token here, as we will skip it
// during parsing anyway (as we must not touch whitespace around conflict
// markers).
Tokens.back()->setType(Type);
Tokens.back()->Tok.setKind(tok::kw___unknown_anytype);
Tokens.push_back(Next);
return true;
}
return false;
}
FormatToken *FormatTokenLexer::getStashedToken() {
// Create a synthesized second '>' or '<' token.
Token Tok = FormatTok->Tok;
StringRef TokenText = FormatTok->TokenText;
unsigned OriginalColumn = FormatTok->OriginalColumn;
FormatTok = new (Allocator.Allocate()) FormatToken;
FormatTok->Tok = Tok;
SourceLocation TokLocation =
FormatTok->Tok.getLocation().getLocWithOffset(Tok.getLength() - 1);
FormatTok->Tok.setLocation(TokLocation);
FormatTok->WhitespaceRange = SourceRange(TokLocation, TokLocation);
FormatTok->TokenText = TokenText;
FormatTok->ColumnWidth = 1;
FormatTok->OriginalColumn = OriginalColumn + 1;
return FormatTok;
}
/// Truncate the current token to the new length and make the lexer continue
/// from the end of the truncated token. Used for other languages that have
/// different token boundaries, like JavaScript in which a comment ends at a
/// line break regardless of whether the line break follows a backslash. Also
/// used to set the lexer to the end of whitespace if the lexer regards
/// whitespace and an unrecognized symbol as one token.
void FormatTokenLexer::truncateToken(size_t NewLen) {
assert(NewLen <= FormatTok->TokenText.size());
resetLexer(SourceMgr.getFileOffset(Lex->getSourceLocation(
Lex->getBufferLocation() - FormatTok->TokenText.size() + NewLen)));
FormatTok->TokenText = FormatTok->TokenText.substr(0, NewLen);
FormatTok->ColumnWidth = encoding::columnWidthWithTabs(
FormatTok->TokenText, FormatTok->OriginalColumn, Style.TabWidth,
Encoding);
FormatTok->Tok.setLength(NewLen);
}
/// Count the length of leading whitespace in a token.
static size_t countLeadingWhitespace(StringRef Text) {
// Basically counting the length matched by this regex.
// "^([\n\r\f\v \t]|(\\\\|\\?\\?/)[\n\r])+"
// Directly using the regex turned out to be slow. With the regex
// version formatting all files in this directory took about 1.25
// seconds. This version took about 0.5 seconds.
const char *Cur = Text.begin();
while (Cur < Text.end()) {
if (isspace(Cur[0])) {
++Cur;
} else if (Cur[0] == '\\' && (Cur[1] == '\n' || Cur[1] == '\r')) {
// A '\' followed by a newline always escapes the newline, regardless
// of whether there is another '\' before it.
// The source has a null byte at the end. So the end of the entire input
// isn't reached yet. Also the lexer doesn't break apart an escaped
// newline.
assert(Text.end() - Cur >= 2);
Cur += 2;
} else if (Cur[0] == '?' && Cur[1] == '?' && Cur[2] == '/' &&
(Cur[3] == '\n' || Cur[3] == '\r')) {
// Newlines can also be escaped by a '?' '?' '/' trigraph. By the way, the
// characters are quoted individually in this comment because if we write
// them together some compilers warn that we have a trigraph in the code.
assert(Text.end() - Cur >= 4);
Cur += 4;
} else {
break;
}
}
return Cur - Text.begin();
}
FormatToken *FormatTokenLexer::getNextToken() {
if (StateStack.top() == LexerState::TOKEN_STASHED) {
StateStack.pop();
return getStashedToken();
}
FormatTok = new (Allocator.Allocate()) FormatToken;
readRawToken(*FormatTok);
SourceLocation WhitespaceStart =
FormatTok->Tok.getLocation().getLocWithOffset(-TrailingWhitespace);
FormatTok->IsFirst = IsFirstToken;
IsFirstToken = false;
// Consume and record whitespace until we find a significant token.
// Some tok::unknown tokens are not just whitespace, e.g. whitespace
// followed by a symbol such as backtick. Those symbols may be
// significant in other languages.
unsigned WhitespaceLength = TrailingWhitespace;
while (FormatTok->isNot(tok::eof)) {
auto LeadingWhitespace = countLeadingWhitespace(FormatTok->TokenText);
if (LeadingWhitespace == 0)
break;
if (LeadingWhitespace < FormatTok->TokenText.size())
truncateToken(LeadingWhitespace);
StringRef Text = FormatTok->TokenText;
bool InEscape = false;
for (int i = 0, e = Text.size(); i != e; ++i) {
switch (Text[i]) {
case '\r':
// If this is a CRLF sequence, break here and the LF will be handled on
// the next loop iteration. Otherwise, this is a single Mac CR, treat it
// the same as a single LF.
if (i + 1 < e && Text[i + 1] == '\n')
break;
LLVM_FALLTHROUGH;
case '\n':
++FormatTok->NewlinesBefore;
if (!InEscape)
FormatTok->HasUnescapedNewline = true;
else
InEscape = false;
FormatTok->LastNewlineOffset = WhitespaceLength + i + 1;
Column = 0;
break;
case '\f':
case '\v':
Column = 0;
break;
case ' ':
++Column;
break;
case '\t':
Column +=
Style.TabWidth - (Style.TabWidth ? Column % Style.TabWidth : 0);
break;
case '\\':
case '?':
case '/':
// The text was entirely whitespace when this loop was entered. Thus
// this has to be an escape sequence.
assert(Text.substr(i, 2) == "\\\r" || Text.substr(i, 2) == "\\\n" ||
Text.substr(i, 4) == "\?\?/\r" ||
Text.substr(i, 4) == "\?\?/\n" ||
(i >= 1 && (Text.substr(i - 1, 4) == "\?\?/\r" ||
Text.substr(i - 1, 4) == "\?\?/\n")) ||
(i >= 2 && (Text.substr(i - 2, 4) == "\?\?/\r" ||
Text.substr(i - 2, 4) == "\?\?/\n")));
InEscape = true;
break;
default:
// This shouldn't happen.
assert(false);
break;
}
}
WhitespaceLength += Text.size();
readRawToken(*FormatTok);
}
if (FormatTok->is(tok::unknown))
FormatTok->setType(TT_ImplicitStringLiteral);
// JavaScript and Java do not allow to escape the end of the line with a
// backslash. Backslashes are syntax errors in plain source, but can occur in
// comments. When a single line comment ends with a \, it'll cause the next
// line of code to be lexed as a comment, breaking formatting. The code below
// finds comments that contain a backslash followed by a line break, truncates
// the comment token at the backslash, and resets the lexer to restart behind
// the backslash.
if ((Style.isJavaScript() || Style.Language == FormatStyle::LK_Java) &&
FormatTok->is(tok::comment) && FormatTok->TokenText.startswith("//")) {
size_t BackslashPos = FormatTok->TokenText.find('\\');
while (BackslashPos != StringRef::npos) {
if (BackslashPos + 1 < FormatTok->TokenText.size() &&
FormatTok->TokenText[BackslashPos + 1] == '\n') {
truncateToken(BackslashPos + 1);
break;
}
BackslashPos = FormatTok->TokenText.find('\\', BackslashPos + 1);
}
}
if (Style.isVerilog()) {
// Verilog uses the backtick instead of the hash for preprocessor stuff.
// And it uses the hash for delays and parameter lists. In order to continue
// using `tok::hash` in other places, the backtick gets marked as the hash
// here. And in order to tell the backtick and hash apart for
// Verilog-specific stuff, the hash becomes an identifier.
if (FormatTok->isOneOf(tok::hash, tok::hashhash)) {
FormatTok->Tok.setKind(tok::raw_identifier);
} else if (FormatTok->is(tok::raw_identifier)) {
if (FormatTok->TokenText == "`") {
FormatTok->Tok.setIdentifierInfo(nullptr);
FormatTok->Tok.setKind(tok::hash);
} else if (FormatTok->TokenText == "``") {
FormatTok->Tok.setIdentifierInfo(nullptr);
FormatTok->Tok.setKind(tok::hashhash);
}
}
}
FormatTok->WhitespaceRange = SourceRange(
WhitespaceStart, WhitespaceStart.getLocWithOffset(WhitespaceLength));
FormatTok->OriginalColumn = Column;
TrailingWhitespace = 0;
if (FormatTok->is(tok::comment)) {
// FIXME: Add the trimmed whitespace to Column.
StringRef UntrimmedText = FormatTok->TokenText;
FormatTok->TokenText = FormatTok->TokenText.rtrim(" \t\v\f");
TrailingWhitespace = UntrimmedText.size() - FormatTok->TokenText.size();
} else if (FormatTok->is(tok::raw_identifier)) {
IdentifierInfo &Info = IdentTable.get(FormatTok->TokenText);
FormatTok->Tok.setIdentifierInfo(&Info);
FormatTok->Tok.setKind(Info.getTokenID());
if (Style.Language == FormatStyle::LK_Java &&
FormatTok->isOneOf(tok::kw_struct, tok::kw_union, tok::kw_delete,
tok::kw_operator)) {
FormatTok->Tok.setKind(tok::identifier);
FormatTok->Tok.setIdentifierInfo(nullptr);
} else if (Style.isJavaScript() &&
FormatTok->isOneOf(tok::kw_struct, tok::kw_union,
tok::kw_operator)) {
FormatTok->Tok.setKind(tok::identifier);
FormatTok->Tok.setIdentifierInfo(nullptr);
}
} else if (FormatTok->is(tok::greatergreater)) {
FormatTok->Tok.setKind(tok::greater);
FormatTok->TokenText = FormatTok->TokenText.substr(0, 1);
++Column;
StateStack.push(LexerState::TOKEN_STASHED);
} else if (FormatTok->is(tok::lessless)) {
FormatTok->Tok.setKind(tok::less);
FormatTok->TokenText = FormatTok->TokenText.substr(0, 1);
++Column;
StateStack.push(LexerState::TOKEN_STASHED);
}
// Now FormatTok is the next non-whitespace token.
StringRef Text = FormatTok->TokenText;
size_t FirstNewlinePos = Text.find('\n');
if (FirstNewlinePos == StringRef::npos) {
// FIXME: ColumnWidth actually depends on the start column, we need to
// take this into account when the token is moved.
FormatTok->ColumnWidth =
encoding::columnWidthWithTabs(Text, Column, Style.TabWidth, Encoding);
Column += FormatTok->ColumnWidth;
} else {
FormatTok->IsMultiline = true;
// FIXME: ColumnWidth actually depends on the start column, we need to
// take this into account when the token is moved.
FormatTok->ColumnWidth = encoding::columnWidthWithTabs(
Text.substr(0, FirstNewlinePos), Column, Style.TabWidth, Encoding);
// The last line of the token always starts in column 0.
// Thus, the length can be precomputed even in the presence of tabs.
FormatTok->LastLineColumnWidth = encoding::columnWidthWithTabs(
Text.substr(Text.find_last_of('\n') + 1), 0, Style.TabWidth, Encoding);
Column = FormatTok->LastLineColumnWidth;
}
if (Style.isCpp()) {
auto it = Macros.find(FormatTok->Tok.getIdentifierInfo());
if (!(Tokens.size() > 0 && Tokens.back()->Tok.getIdentifierInfo() &&
Tokens.back()->Tok.getIdentifierInfo()->getPPKeywordID() ==
tok::pp_define) &&
it != Macros.end()) {
FormatTok->setType(it->second);
if (it->second == TT_IfMacro) {
// The lexer token currently has type tok::kw_unknown. However, for this
// substitution to be treated correctly in the TokenAnnotator, faking
// the tok value seems to be needed. Not sure if there's a more elegant
// way.
FormatTok->Tok.setKind(tok::kw_if);
}
} else if (FormatTok->is(tok::identifier)) {
if (MacroBlockBeginRegex.match(Text))
FormatTok->setType(TT_MacroBlockBegin);
else if (MacroBlockEndRegex.match(Text))
FormatTok->setType(TT_MacroBlockEnd);
}
}
return FormatTok;
}
bool FormatTokenLexer::readRawTokenVerilogSpecific(Token &Tok) {
// In Verilog the quote is not a character literal.
//
// Make the backtick and double backtick identifiers to match against them
// more easily.
//
// In Verilog an escaped identifier starts with backslash and ends with
// whitespace. Unless that whitespace is an escaped newline. A backslash can
// also begin an escaped newline outside of an escaped identifier. We check
// for that outside of the Regex since we can't use negative lookhead
// assertions. Simply changing the '*' to '+' breaks stuff as the escaped
// identifier may have a length of 0 according to Section A.9.3.
// FIXME: If there is an escaped newline in the middle of an escaped
// identifier, allow for pasting the two lines together, But escaped
// identifiers usually occur only in generated code anyway.
static const llvm::Regex VerilogToken(R"re(^('|``?|\\(\\)re"
"(\r?\n|\r)|[^[:space:]])*)");
SmallVector<StringRef, 4> Matches;
const char *Start = Lex->getBufferLocation();
if (!VerilogToken.match(StringRef(Start, Lex->getBuffer().end() - Start),
&Matches)) {
return false;
}
// There is a null byte at the end of the buffer, so we don't have to check
// Start[1] is within the buffer.
if (Start[0] == '\\' && (Start[1] == '\r' || Start[1] == '\n'))
return false;
size_t Len = Matches[0].size();
// The kind has to be an identifier so we can match it against those defined
// in Keywords. The kind has to be set before the length because the setLength
// function checks that the kind is not an annotation.
Tok.setKind(tok::raw_identifier);
Tok.setLength(Len);
Tok.setLocation(Lex->getSourceLocation(Start, Len));
Tok.setRawIdentifierData(Start);
Lex->seek(Lex->getCurrentBufferOffset() + Len, /*IsAtStartofline=*/false);
return true;
}
void FormatTokenLexer::readRawToken(FormatToken &Tok) {
// For Verilog, first see if there is a special token, and fall back to the
// normal lexer if there isn't one.
if (!Style.isVerilog() || !readRawTokenVerilogSpecific(Tok.Tok))
Lex->LexFromRawLexer(Tok.Tok);
Tok.TokenText = StringRef(SourceMgr.getCharacterData(Tok.Tok.getLocation()),
Tok.Tok.getLength());
// For formatting, treat unterminated string literals like normal string
// literals.
if (Tok.is(tok::unknown)) {
if (!Tok.TokenText.empty() && Tok.TokenText[0] == '"') {
Tok.Tok.setKind(tok::string_literal);
Tok.IsUnterminatedLiteral = true;
} else if (Style.isJavaScript() && Tok.TokenText == "''") {
Tok.Tok.setKind(tok::string_literal);
}
}
if ((Style.isJavaScript() || Style.Language == FormatStyle::LK_Proto ||
Style.Language == FormatStyle::LK_TextProto) &&
Tok.is(tok::char_constant)) {
Tok.Tok.setKind(tok::string_literal);
}
if (Tok.is(tok::comment) && (Tok.TokenText == "// clang-format on" ||
Tok.TokenText == "/* clang-format on */")) {
FormattingDisabled = false;
}
Tok.Finalized = FormattingDisabled;
if (Tok.is(tok::comment) && (Tok.TokenText == "// clang-format off" ||
Tok.TokenText == "/* clang-format off */")) {
FormattingDisabled = true;
}
}
void FormatTokenLexer::resetLexer(unsigned Offset) {
StringRef Buffer = SourceMgr.getBufferData(ID);
LangOpts = getFormattingLangOpts(Style);
Lex.reset(new Lexer(SourceMgr.getLocForStartOfFile(ID), LangOpts,
Buffer.begin(), Buffer.begin() + Offset, Buffer.end()));
Lex->SetKeepWhitespaceMode(true);
TrailingWhitespace = 0;
}
} // namespace format
} // namespace clang