Extend -Wdynamic-class-memaccess to records containing dynamic classes
Reviewers: rtrieu
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4325
llvm-svn: 211972
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index adc4c4a..72d3b27 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3983,15 +3983,35 @@
return true;
}
-/// \brief Determine whether the given type is a dynamic class type (e.g.,
-/// whether it has a vtable).
-static bool isDynamicClassType(QualType T) {
- if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
- if (CXXRecordDecl *Definition = Record->getDefinition())
- if (Definition->isDynamicClass())
- return true;
-
- return false;
+/// \brief Determine whether the given type is or contains a dynamic class type
+/// (e.g., whether it has a vtable).
+static const CXXRecordDecl *getContainedDynamicClass(QualType T,
+ bool &IsContained) {
+ // Look through array types while ignoring qualifiers.
+ const Type *Ty = T->getBaseElementTypeUnsafe();
+ IsContained = false;
+
+ const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
+ RD = RD ? RD->getDefinition() : nullptr;
+ if (!RD)
+ return nullptr;
+
+ if (RD->isDynamicClass())
+ return RD;
+
+ // Check all the fields. If any bases were dynamic, the class is dynamic.
+ // It's impossible for a class to transitively contain itself by value, so
+ // infinite recursion is impossible.
+ for (auto *FD : RD->fields()) {
+ bool SubContained;
+ if (const CXXRecordDecl *ContainedRD =
+ getContainedDynamicClass(FD->getType(), SubContained)) {
+ IsContained = true;
+ return ContainedRD;
+ }
+ }
+
+ return nullptr;
}
/// \brief If E is a sizeof expression, returns its argument expression,
@@ -4135,7 +4155,9 @@
}
// Always complain about dynamic classes.
- if (isDynamicClassType(PointeeTy)) {
+ bool IsContained;
+ if (const CXXRecordDecl *ContainedRD =
+ getContainedDynamicClass(PointeeTy, IsContained)) {
unsigned OperationType = 0;
// "overwritten" if we're warning about the destination for any call
@@ -4153,8 +4175,7 @@
Dest->getExprLoc(), Dest,
PDiag(diag::warn_dyn_class_memaccess)
<< (BId == Builtin::BImemcmp ? ArgIdx + 2 : ArgIdx)
- << FnName << PointeeTy
- << OperationType
+ << FnName << IsContained << ContainedRD << OperationType
<< Call->getCallee()->getSourceRange());
} else if (PointeeTy.hasNonTrivialObjCLifetime() &&
BId != Builtin::BImemset)