forked from OSchip/llvm-project
69 lines
2.3 KiB
C++
69 lines
2.3 KiB
C++
//===--- DefaultOperatorNewCheck.cpp - clang-tidy --------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "DefaultOperatorNewAlignmentCheck.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/ASTMatchers/ASTMatchFinder.h"
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#include "clang/Basic/TargetInfo.h"
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using namespace clang::ast_matchers;
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namespace clang {
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namespace tidy {
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namespace cert {
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void DefaultOperatorNewAlignmentCheck::registerMatchers(MatchFinder *Finder) {
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Finder->addMatcher(
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cxxNewExpr(unless(hasAnyPlacementArg(anything()))).bind("new"), this);
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}
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void DefaultOperatorNewAlignmentCheck::check(
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const MatchFinder::MatchResult &Result) {
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// Get the found 'new' expression.
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const auto *NewExpr = Result.Nodes.getNodeAs<CXXNewExpr>("new");
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QualType T = NewExpr->getAllocatedType();
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// Dependent types do not have fixed alignment.
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if (T->isDependentType())
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return;
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const TagDecl *D = T->getAsTagDecl();
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// Alignment can not be obtained for undefined type.
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if (!D || !D->getDefinition() || !D->isCompleteDefinition())
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return;
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ASTContext &Context = D->getASTContext();
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// Check if no alignment was specified for the type.
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if (!Context.isAlignmentRequired(T))
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return;
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// The user-specified alignment (in bits).
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unsigned SpecifiedAlignment = D->getMaxAlignment();
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// Double-check if no alignment was specified.
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if (!SpecifiedAlignment)
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return;
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// The alignment used by default 'operator new' (in bits).
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unsigned DefaultNewAlignment = Context.getTargetInfo().getNewAlign();
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bool OverAligned = SpecifiedAlignment > DefaultNewAlignment;
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bool HasDefaultOperatorNew =
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!NewExpr->getOperatorNew() || NewExpr->getOperatorNew()->isImplicit();
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unsigned CharWidth = Context.getTargetInfo().getCharWidth();
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if (HasDefaultOperatorNew && OverAligned)
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diag(NewExpr->getBeginLoc(),
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"allocation function returns a pointer with alignment %0 but the "
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"over-aligned type being allocated requires alignment %1")
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<< (DefaultNewAlignment / CharWidth)
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<< (SpecifiedAlignment / CharWidth);
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}
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} // namespace cert
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} // namespace tidy
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} // namespace clang
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