diff options
Diffstat (limited to 'lib/StaticAnalyzer/Checkers/PaddingChecker.cpp')
-rw-r--r-- | lib/StaticAnalyzer/Checkers/PaddingChecker.cpp | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/lib/StaticAnalyzer/Checkers/PaddingChecker.cpp b/lib/StaticAnalyzer/Checkers/PaddingChecker.cpp index b1255243be..dc361ad537 100644 --- a/lib/StaticAnalyzer/Checkers/PaddingChecker.cpp +++ b/lib/StaticAnalyzer/Checkers/PaddingChecker.cpp @@ -41,7 +41,8 @@ public: BugReporter &BRArg) const { BR = &BRArg; AllowedPad = - MGR.getAnalyzerOptions().getOptionAsInteger("AllowedPad", 24, this); + MGR.getAnalyzerOptions() + .getCheckerIntegerOption("AllowedPad", 24, this); assert(AllowedPad >= 0 && "AllowedPad option should be non-negative"); // The calls to checkAST* from AnalysisConsumer don't @@ -75,6 +76,20 @@ public: if (shouldSkipDecl(RD)) return; + // TODO: Figure out why we are going through declarations and not only + // definitions. + if (!(RD = RD->getDefinition())) + return; + + // This is the simplest correct case: a class with no fields and one base + // class. Other cases are more complicated because of how the base classes + // & fields might interact, so we don't bother dealing with them. + // TODO: Support other combinations of base classes and fields. + if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) + if (CXXRD->field_empty() && CXXRD->getNumBases() == 1) + return visitRecord(CXXRD->bases().begin()->getType()->getAsRecordDecl(), + PadMultiplier); + auto &ASTContext = RD->getASTContext(); const ASTRecordLayout &RL = ASTContext.getASTRecordLayout(RD); assert(llvm::isPowerOf2_64(RL.getAlignment().getQuantity())); @@ -112,12 +127,15 @@ public: if (RT == nullptr) return; - // TODO: Recurse into the fields and base classes to see if any - // of those have excess padding. + // TODO: Recurse into the fields to see if they have excess padding. visitRecord(RT->getDecl(), Elts); } bool shouldSkipDecl(const RecordDecl *RD) const { + // TODO: Figure out why we are going through declarations and not only + // definitions. + if (!(RD = RD->getDefinition())) + return true; auto Location = RD->getLocation(); // If the construct doesn't have a source file, then it's not something // we want to diagnose. @@ -132,13 +150,14 @@ public: // Not going to attempt to optimize unions. if (RD->isUnion()) return true; - // How do you reorder fields if you haven't got any? - if (RD->field_empty()) - return true; if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) { // Tail padding with base classes ends up being very complicated. - // We will skip objects with base classes for now. - if (CXXRD->getNumBases() != 0) + // We will skip objects with base classes for now, unless they do not + // have fields. + // TODO: Handle more base class scenarios. + if (!CXXRD->field_empty() && CXXRD->getNumBases() != 0) + return true; + if (CXXRD->field_empty() && CXXRD->getNumBases() != 1) return true; // Virtual bases are complicated, skipping those for now. if (CXXRD->getNumVBases() != 0) @@ -150,6 +169,10 @@ public: if (CXXRD->getTypeForDecl()->isInstantiationDependentType()) return true; } + // How do you reorder fields if you haven't got any? + else if (RD->field_empty()) + return true; + auto IsTrickyField = [](const FieldDecl *FD) -> bool { // Bitfield layout is hard. if (FD->isBitField()) @@ -323,7 +346,7 @@ public: BR->emitReport(std::move(Report)); } }; -} +} // namespace void ento::registerPaddingChecker(CheckerManager &Mgr) { Mgr.registerChecker<PaddingChecker>(); |