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Diffstat (limited to 'clang-tools-extra/clang-tidy/misc/MacroParenthesesCheck.cpp')
| -rw-r--r-- | clang-tools-extra/clang-tidy/misc/MacroParenthesesCheck.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/clang-tools-extra/clang-tidy/misc/MacroParenthesesCheck.cpp b/clang-tools-extra/clang-tidy/misc/MacroParenthesesCheck.cpp new file mode 100644 index 00000000000..1649d3fee64 --- /dev/null +++ b/clang-tools-extra/clang-tidy/misc/MacroParenthesesCheck.cpp @@ -0,0 +1,192 @@ +//===--- MacroParenthesesCheck.cpp - clang-tidy----------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "MacroParenthesesCheck.h" +#include "clang/Frontend/CompilerInstance.h" +#include "clang/Lex/PPCallbacks.h" +#include "clang/Lex/Preprocessor.h" + +namespace clang { +namespace tidy { + +namespace { +class MacroParenthesesPPCallbacks : public PPCallbacks { +public: + explicit MacroParenthesesPPCallbacks(Preprocessor *PP, + MacroParenthesesCheck *Check) + : PP(PP), Check(Check) {} + + void MacroDefined(const Token &MacroNameTok, + const MacroDirective *MD) override { + replacementList(MacroNameTok, MD->getMacroInfo()); + argument(MacroNameTok, MD->getMacroInfo()); + } + +private: + /// Replacement list with calculations should be enclosed in parentheses. + void replacementList(const Token &MacroNameTok, const MacroInfo *MI); + + /// Arguments should be enclosed in parentheses. + void argument(const Token &MacroNameTok, const MacroInfo *MI); + + Preprocessor *PP; + MacroParenthesesCheck *Check; +}; + +/// Is argument surrounded properly with parentheses/braces/squares/commas? +bool isSurroundedLeft(const Token &T) { + return T.isOneOf(tok::l_paren, tok::l_brace, tok::l_square, tok::comma, + tok::semi); +} + +/// Is argument surrounded properly with parentheses/braces/squares/commas? +bool isSurroundedRight(const Token &T) { + return T.isOneOf(tok::r_paren, tok::r_brace, tok::r_square, tok::comma, + tok::semi); +} + +/// Is given TokenKind a keyword? +bool isKeyword(const Token &T) { + /// \TODO better matching of keywords to avoid false positives + return T.isOneOf(tok::kw_case, tok::kw_const, tok::kw_struct); +} + +/// Warning is written when one of these operators are not within parentheses. +bool isWarnOp(const Token &T) { + /// \TODO This is an initial list of operators. It can be tweaked later to + /// get more positives or perhaps avoid some false positive. + return T.isOneOf(tok::plus, tok::minus, tok::star, tok::slash, tok::percent, + tok::amp, tok::pipe, tok::caret); +} +} + +void MacroParenthesesPPCallbacks::replacementList(const Token &MacroNameTok, + const MacroInfo *MI) { + // Count how deep we are in parentheses/braces/squares. + int Count = 0; + + // SourceLocation for error + SourceLocation Loc; + + for (auto TI = MI->tokens_begin(), TE = MI->tokens_end(); TI != TE; ++TI) { + const Token &Tok = *TI; + // Replacement list contains keywords, don't warn about it. + if (isKeyword(Tok)) + return; + // When replacement list contains comma/semi don't warn about it. + if (Count == 0 && Tok.isOneOf(tok::comma, tok::semi)) + return; + if (Tok.isOneOf(tok::l_paren, tok::l_brace, tok::l_square)) { + ++Count; + } else if (Tok.isOneOf(tok::r_paren, tok::r_brace, tok::r_square)) { + --Count; + // If there are unbalanced parentheses don't write any warning + if (Count < 0) + return; + } else if (Count == 0 && isWarnOp(Tok)) { + // Heuristic for macros that are clearly not intended to be enclosed in + // parentheses, macro starts with operator. For example: + // #define X *10 + if (TI == MI->tokens_begin() && (TI + 1) != TE && + !Tok.isOneOf(tok::plus, tok::minus)) + return; + // Don't warn about this macro if the last token is a star. For example: + // #define X void * + if ((TE - 1)->is(tok::star)) + return; + + Loc = Tok.getLocation(); + } + } + if (Loc.isValid()) { + const Token &Last = *(MI->tokens_end() - 1); + Check->diag(Loc, "macro replacement list should be enclosed in parentheses") + << FixItHint::CreateInsertion(MI->tokens_begin()->getLocation(), "(") + << FixItHint::CreateInsertion(Last.getLocation().getLocWithOffset( + PP->getSpelling(Last).length()), + ")"); + } +} + +void MacroParenthesesPPCallbacks::argument(const Token &MacroNameTok, + const MacroInfo *MI) { + + for (auto TI = MI->tokens_begin(), TE = MI->tokens_end(); TI != TE; ++TI) { + // First token. + if (TI == MI->tokens_begin()) + continue; + + // Last token. + if ((TI + 1) == MI->tokens_end()) + continue; + + const Token &Prev = *(TI - 1); + const Token &Next = *(TI + 1); + + const Token &Tok = *TI; + + // Only interested in identifiers. + if (!Tok.isOneOf(tok::identifier, tok::raw_identifier)) + continue; + + // Only interested in macro arguments. + if (MI->getArgumentNum(Tok.getIdentifierInfo()) < 0) + continue; + + // Argument is surrounded with parentheses/squares/braces/commas. + if (isSurroundedLeft(Prev) && isSurroundedRight(Next)) + continue; + + // Don't warn after hash/hashhash or before hashhash. + if (Prev.isOneOf(tok::hash, tok::hashhash) || Next.is(tok::hashhash)) + continue; + + // Argument is a struct member. + if (Prev.isOneOf(tok::period, tok::arrow)) + continue; + + // String concatenation. + if (isStringLiteral(Prev.getKind()) || isStringLiteral(Next.getKind())) + continue; + + // Type/Var. + if (isAnyIdentifier(Prev.getKind()) || isKeyword(Prev) || + isAnyIdentifier(Next.getKind()) || isKeyword(Next)) + continue; + + // Initialization. + if (Next.is(tok::l_paren)) + continue; + + // Cast. + if (Prev.is(tok::l_paren) && Next.is(tok::star) && + TI + 2 != MI->tokens_end() && (TI + 2)->is(tok::r_paren)) + continue; + + // Assignment. + if (Prev.is(tok::equal) && Next.is(tok::semi)) + continue; + + Check->diag(Tok.getLocation(), "macro argument should be enclosed in " + "parentheses") + << FixItHint::CreateInsertion(Tok.getLocation(), "(") + << FixItHint::CreateInsertion(Tok.getLocation().getLocWithOffset( + PP->getSpelling(Tok).length()), + ")"); + } +} + +void MacroParenthesesCheck::registerPPCallbacks(CompilerInstance &Compiler) { + Compiler.getPreprocessor().addPPCallbacks( + llvm::make_unique<MacroParenthesesPPCallbacks>( + &Compiler.getPreprocessor(), this)); +} + +} // namespace tidy +} // namespace clang |
