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Diffstat (limited to 'compilerplugins/clang/literaltoboolconversion.cxx')
| -rw-r--r-- | compilerplugins/clang/literaltoboolconversion.cxx | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/compilerplugins/clang/literaltoboolconversion.cxx b/compilerplugins/clang/literaltoboolconversion.cxx new file mode 100644 index 0000000000..9894daec51 --- /dev/null +++ b/compilerplugins/clang/literaltoboolconversion.cxx @@ -0,0 +1,232 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ +#ifndef LO_CLANG_SHARED_PLUGINS + +#include <cassert> +#include <limits> + +#include "clang/Lex/Lexer.h" + +#include "compat.hxx" +#include "plugin.hxx" + +namespace { + +class LiteralToBoolConversion: + public loplugin::FilteringRewritePlugin<LiteralToBoolConversion> +{ +public: + explicit LiteralToBoolConversion(loplugin::InstantiationData const & data): + FilteringRewritePlugin(data) {} + + virtual void run() override + { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); } + + bool VisitImplicitCastExpr(ImplicitCastExpr const * expr); + + bool PreTraverseLinkageSpecDecl(LinkageSpecDecl * decl); + bool PostTraverseLinkageSpecDecl(LinkageSpecDecl * decl, bool); + bool TraverseLinkageSpecDecl(LinkageSpecDecl * decl); + +private: + bool isFromCIncludeFile(SourceLocation spellingLocation) const; + + bool isSharedCAndCppCode(SourceLocation location) const; + + void handleImplicitCastSubExpr( + ImplicitCastExpr const * castExpr, Expr const * subExpr); + + unsigned int externCContexts_ = 0; +}; + +bool LiteralToBoolConversion::VisitImplicitCastExpr( + ImplicitCastExpr const * expr) +{ + if (ignoreLocation(expr)) { + return true; + } + if (!expr->getType()->isBooleanType()) { + return true; + } + handleImplicitCastSubExpr(expr, expr->getSubExpr()); + return true; +} + +bool LiteralToBoolConversion::PreTraverseLinkageSpecDecl(LinkageSpecDecl *) { + assert(externCContexts_ != std::numeric_limits<unsigned int>::max()); //TODO + ++externCContexts_; + return true; +} + +bool LiteralToBoolConversion::PostTraverseLinkageSpecDecl(LinkageSpecDecl *, bool) { + assert(externCContexts_ != 0); + --externCContexts_; + return true; +} + +bool LiteralToBoolConversion::TraverseLinkageSpecDecl(LinkageSpecDecl * decl) { + PreTraverseLinkageSpecDecl(decl); + bool ret = RecursiveASTVisitor::TraverseLinkageSpecDecl(decl); + PostTraverseLinkageSpecDecl(decl, ret); + return ret; +} + +bool LiteralToBoolConversion::isFromCIncludeFile( + SourceLocation spellingLocation) const +{ + return !compiler.getSourceManager().isInMainFile(spellingLocation) + && (StringRef( + compiler.getSourceManager().getPresumedLoc(spellingLocation) + .getFilename()) + .endswith(".h")); +} + +bool LiteralToBoolConversion::isSharedCAndCppCode(SourceLocation location) const +{ + // Assume that code is intended to be shared between C and C++ if it comes + // from an include file ending in .h, and is either in an extern "C" context + // or the body of a macro definition: + return + isFromCIncludeFile(compiler.getSourceManager().getSpellingLoc(location)) + && (externCContexts_ != 0 + || compiler.getSourceManager().isMacroBodyExpansion(location)); +} + +void LiteralToBoolConversion::handleImplicitCastSubExpr( + ImplicitCastExpr const * castExpr, Expr const * subExpr) +{ + Expr const * expr2 = subExpr; + // track sub-expr with potential parens, to e.g. rewrite all of expanded + // + // #define sal_False ((sal_Bool)0) + // + // including the parens + subExpr = expr2->IgnoreParenCasts(); + for (;;) { + BinaryOperator const * op = dyn_cast<BinaryOperator>(subExpr); + if (op == nullptr || op->getOpcode() != BO_Comma) { + break; + } + expr2 = op->getRHS(); + subExpr = expr2->IgnoreParenCasts(); + } + if (subExpr->getType()->isBooleanType()) { + return; + } + ConditionalOperator const * op = dyn_cast<ConditionalOperator>(subExpr); + if (op != nullptr) { + handleImplicitCastSubExpr(castExpr, op->getTrueExpr()); + handleImplicitCastSubExpr(castExpr, op->getFalseExpr()); + return; + } + if (!subExpr->isValueDependent()) { + if (auto const res = subExpr->getIntegerConstantExpr(compiler.getASTContext())) { + if (res->getLimitedValue() <= 1) + { + SourceLocation loc { subExpr->getBeginLoc() }; + while (compiler.getSourceManager().isMacroArgExpansion(loc)) { + loc = compiler.getSourceManager().getImmediateMacroCallerLoc(loc); + } + if (compiler.getSourceManager().isMacroBodyExpansion(loc)) { + StringRef name { Lexer::getImmediateMacroName( + loc, compiler.getSourceManager(), compiler.getLangOpts()) }; + if (name == "sal_False" || name == "sal_True") { + loc = compat::getImmediateExpansionRange(compiler.getSourceManager(), loc) + .first; + } + if (isSharedCAndCppCode(loc)) { + return; + } + } + } + } + } + if (isa<clang::StringLiteral>(subExpr)) { + SourceLocation loc { subExpr->getBeginLoc() }; + if (compiler.getSourceManager().isMacroArgExpansion(loc) + && (Lexer::getImmediateMacroName( + loc, compiler.getSourceManager(), compiler.getLangOpts()) + == "assert")) + { + return; + } + } + if (isa<IntegerLiteral>(subExpr) || isa<CharacterLiteral>(subExpr) + || isa<FloatingLiteral>(subExpr) || isa<ImaginaryLiteral>(subExpr) + || isa<clang::StringLiteral>(subExpr)) + { + bool bRewritten = false; + if (rewriter != nullptr) { + SourceLocation loc { compiler.getSourceManager().getExpansionLoc( + expr2->getBeginLoc()) }; + if (compiler.getSourceManager().getExpansionLoc(expr2->getEndLoc()) + == loc) + { + char const * s = compiler.getSourceManager().getCharacterData( + loc); + unsigned n = Lexer::MeasureTokenLength( + expr2->getEndLoc(), compiler.getSourceManager(), + compiler.getLangOpts()); + std::string tok { s, n }; + if (tok == "sal_False" || tok == "0") { + bRewritten = replaceText( + compiler.getSourceManager().getExpansionLoc( + expr2->getBeginLoc()), + n, "false"); + } else if (tok == "sal_True" || tok == "1") { + bRewritten = replaceText( + compiler.getSourceManager().getExpansionLoc( + expr2->getBeginLoc()), + n, "true"); + } + } + } + if (!bRewritten) { + report( + DiagnosticsEngine::Warning, + "implicit conversion (%0) of literal of type %1 to %2", + expr2->getBeginLoc()) + << castExpr->getCastKindName() << subExpr->getType() + << castExpr->getType() << expr2->getSourceRange(); + } + } else if (subExpr->isNullPointerConstant( + compiler.getASTContext(), Expr::NPC_ValueDependentIsNull) + > Expr::NPCK_ZeroExpression) + { + // The test above originally checked for != Expr::NPCK_NotNull, but in non-C++11 + // mode we can get also Expr::NPCK_ZeroExpression inside templates, even though + // the expression is actually not a null pointer. Clang bug or C++98 misfeature? + // See Clang's NPCK_ZeroExpression declaration and beginning of isNullPointerConstant(). + static_assert( Expr::NPCK_NotNull == 0 && Expr::NPCK_ZeroExpression == 1, "Clang API change" ); + report( + DiagnosticsEngine::Warning, + ("implicit conversion (%0) of null pointer constant of type %1 to" + " %2"), + expr2->getBeginLoc()) + << castExpr->getCastKindName() << subExpr->getType() + << castExpr->getType() << expr2->getSourceRange(); + } else if (!subExpr->isValueDependent()) { + if (auto const res = subExpr->getIntegerConstantExpr(compiler.getASTContext())) { + report( + DiagnosticsEngine::Warning, + ("implicit conversion (%0) of integer constant expression of type" + " %1 with value %2 to %3"), + expr2->getBeginLoc()) + << castExpr->getCastKindName() << subExpr->getType() + << compat::toString(*res, 10) << castExpr->getType() + << expr2->getSourceRange(); + } + } +} + +loplugin::Plugin::Registration<LiteralToBoolConversion> literaltoboolconversion("literaltoboolconversion"); + +} // namespace + +#endif // LO_CLANG_SHARED_PLUGINS |