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Diffstat (limited to 'lib/Format/FormatTokenLexer.cpp')
| -rw-r--r-- | lib/Format/FormatTokenLexer.cpp | 597 |
1 files changed, 597 insertions, 0 deletions
diff --git a/lib/Format/FormatTokenLexer.cpp b/lib/Format/FormatTokenLexer.cpp new file mode 100644 index 0000000000000..9778f84732d64 --- /dev/null +++ b/lib/Format/FormatTokenLexer.cpp @@ -0,0 +1,597 @@ +//===--- FormatTokenLexer.cpp - Lex FormatTokens -------------*- C++ ----*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// \brief 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, + const FormatStyle &Style, + encoding::Encoding Encoding) + : FormatTok(nullptr), IsFirstToken(true), GreaterStashed(false), + LessStashed(false), Column(0), TrailingWhitespace(0), + SourceMgr(SourceMgr), ID(ID), Style(Style), + IdentTable(getFormattingLangOpts(Style)), Keywords(IdentTable), + Encoding(Encoding), FirstInLineIndex(0), FormattingDisabled(false), + MacroBlockBeginRegex(Style.MacroBlockBegin), + MacroBlockEndRegex(Style.MacroBlockEnd) { + Lex.reset(new Lexer(ID, SourceMgr.getBuffer(ID), SourceMgr, + getFormattingLangOpts(Style))); + Lex->SetKeepWhitespaceMode(true); + + for (const std::string &ForEachMacro : Style.ForEachMacros) + ForEachMacros.push_back(&IdentTable.get(ForEachMacro)); + std::sort(ForEachMacros.begin(), ForEachMacros.end()); +} + +ArrayRef<FormatToken *> FormatTokenLexer::lex() { + assert(Tokens.empty()); + assert(FirstInLineIndex == 0); + do { + Tokens.push_back(getNextToken()); + if (Style.Language == FormatStyle::LK_JavaScript) { + tryParseJSRegexLiteral(); + tryParseTemplateString(); + } + tryMergePreviousTokens(); + if (Tokens.back()->NewlinesBefore > 0 || Tokens.back()->IsMultiline) + FirstInLineIndex = Tokens.size() - 1; + } while (Tokens.back()->Tok.isNot(tok::eof)); + return Tokens; +} + +void FormatTokenLexer::tryMergePreviousTokens() { + if (tryMerge_TMacro()) + return; + if (tryMergeConflictMarkers()) + return; + if (tryMergeLessLess()) + return; + + if (Style.Language == FormatStyle::LK_JavaScript) { + 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 JSRightArrow[] = {tok::equal, tok::greater}; + // 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(JSRightArrow, TT_JsFatArrow)) + return; + } +} + +bool FormatTokenLexer::tryMergeLessLess() { + // Merge X,less,less,Y into X,lessless,Y unless X or Y is less. + if (Tokens.size() < 3) + return false; + + bool FourthTokenIsLess = false; + if (Tokens.size() > 3) + FourthTokenIsLess = (Tokens.end() - 4)[0]->is(tok::less); + + auto First = Tokens.end() - 3; + if (First[2]->is(tok::less) || First[1]->isNot(tok::less) || + First[0]->isNot(tok::less) || FourthTokenIsLess) + return false; + + // Only merge if there currently is no whitespace between the two "<". + if (First[1]->WhitespaceRange.getBegin() != + First[1]->WhitespaceRange.getEnd()) + 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]->WhitespaceRange.getBegin() != + First[i]->WhitespaceRange.getEnd()) + 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]->Type = 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. + if (Prev->isOneOf(tok::plusplus, tok::minusminus)) + 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 (auto I = Tokens.rbegin() + 1, E = Tokens.rend(); I != E; ++I) { + // NB: Because previous pointers are not initialized yet, this cannot use + // Token.getPreviousNonComment. + if ((*I)->isNot(tok::comment)) { + Prev = *I; + 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->Type = 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::tryParseTemplateString() { + FormatToken *BacktickToken = Tokens.back(); + if (!BacktickToken->is(tok::unknown) || BacktickToken->TokenText != "`") + return; + + // '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 != '`'; ++Offset) { + if (*Offset == '\\') + ++Offset; // Skip the escaped character. + } + + StringRef LiteralText(TmplBegin, Offset - TmplBegin + 1); + BacktickToken->Type = 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, LiteralText.size()), StartColumn, + Style.TabWidth, Encoding); + } + + resetLexer(SourceMgr.getFileOffset(Lex->getSourceLocation(Offset + 1))); +} + +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; + 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.getBuffer(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()->Type = 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; +} + +FormatToken *FormatTokenLexer::getNextToken() { + if (GreaterStashed) { + GreaterStashed = false; + return getStashedToken(); + } + if (LessStashed) { + LessStashed = false; + 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. + unsigned WhitespaceLength = TrailingWhitespace; + while (FormatTok->Tok.is(tok::unknown)) { + StringRef Text = FormatTok->TokenText; + auto EscapesNewline = [&](int pos) { + // A '\r' here is just part of '\r\n'. Skip it. + if (pos >= 0 && Text[pos] == '\r') + --pos; + // See whether there is an odd number of '\' before this. + unsigned count = 0; + for (; pos >= 0; --pos, ++count) + if (Text[pos] != '\\') + break; + return count & 1; + }; + // FIXME: This miscounts tok:unknown tokens that are not just + // whitespace, e.g. a '`' character. + for (int i = 0, e = Text.size(); i != e; ++i) { + switch (Text[i]) { + case '\n': + ++FormatTok->NewlinesBefore; + FormatTok->HasUnescapedNewline = !EscapesNewline(i - 1); + FormatTok->LastNewlineOffset = WhitespaceLength + i + 1; + Column = 0; + break; + case '\r': + FormatTok->LastNewlineOffset = WhitespaceLength + i + 1; + Column = 0; + break; + case '\f': + case '\v': + Column = 0; + break; + case ' ': + ++Column; + break; + case '\t': + Column += Style.TabWidth - Column % Style.TabWidth; + break; + case '\\': + if (i + 1 == e || (Text[i + 1] != '\r' && Text[i + 1] != '\n')) + FormatTok->Type = TT_ImplicitStringLiteral; + break; + default: + FormatTok->Type = TT_ImplicitStringLiteral; + break; + } + if (FormatTok->Type == TT_ImplicitStringLiteral) + break; + } + + if (FormatTok->is(TT_ImplicitStringLiteral)) + break; + WhitespaceLength += FormatTok->Tok.getLength(); + + readRawToken(*FormatTok); + } + + // In case the token starts with escaped newlines, we want to + // take them into account as whitespace - this pattern is quite frequent + // in macro definitions. + // FIXME: Add a more explicit test. + while (FormatTok->TokenText.size() > 1 && FormatTok->TokenText[0] == '\\' && + FormatTok->TokenText[1] == '\n') { + ++FormatTok->NewlinesBefore; + WhitespaceLength += 2; + FormatTok->LastNewlineOffset = 2; + Column = 0; + FormatTok->TokenText = FormatTok->TokenText.substr(2); + } + + FormatTok->WhitespaceRange = SourceRange( + WhitespaceStart, WhitespaceStart.getLocWithOffset(WhitespaceLength)); + + FormatTok->OriginalColumn = Column; + + TrailingWhitespace = 0; + if (FormatTok->Tok.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->Tok.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.Language == FormatStyle::LK_JavaScript && + FormatTok->isOneOf(tok::kw_struct, tok::kw_union, + tok::kw_operator)) { + FormatTok->Tok.setKind(tok::identifier); + FormatTok->Tok.setIdentifierInfo(nullptr); + } + } else if (FormatTok->Tok.is(tok::greatergreater)) { + FormatTok->Tok.setKind(tok::greater); + FormatTok->TokenText = FormatTok->TokenText.substr(0, 1); + GreaterStashed = true; + } else if (FormatTok->Tok.is(tok::lessless)) { + FormatTok->Tok.setKind(tok::less); + FormatTok->TokenText = FormatTok->TokenText.substr(0, 1); + LessStashed = true; + } + + // 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.Language == FormatStyle::LK_Cpp) { + if (!(Tokens.size() > 0 && Tokens.back()->Tok.getIdentifierInfo() && + Tokens.back()->Tok.getIdentifierInfo()->getPPKeywordID() == + tok::pp_define) && + std::find(ForEachMacros.begin(), ForEachMacros.end(), + FormatTok->Tok.getIdentifierInfo()) != ForEachMacros.end()) { + FormatTok->Type = TT_ForEachMacro; + } else if (FormatTok->is(tok::identifier)) { + if (MacroBlockBeginRegex.match(Text)) { + FormatTok->Type = TT_MacroBlockBegin; + } else if (MacroBlockEndRegex.match(Text)) { + FormatTok->Type = TT_MacroBlockEnd; + } + } + } + + return FormatTok; +} + +void FormatTokenLexer::readRawToken(FormatToken &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.Language == FormatStyle::LK_JavaScript && + Tok.TokenText == "''") { + Tok.Tok.setKind(tok::string_literal); + } + } + + if (Style.Language == FormatStyle::LK_JavaScript && + 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); + Lex.reset(new Lexer(SourceMgr.getLocForStartOfFile(ID), + getFormattingLangOpts(Style), Buffer.begin(), + Buffer.begin() + Offset, Buffer.end())); + Lex->SetKeepWhitespaceMode(true); + TrailingWhitespace = 0; +} + +} // namespace format +} // namespace clang |