Fix static analyzer crash when casting from an incomplete type
Summary:
When doing a reinterpret+dynamic cast from an incomplete type, the analyzer
would crash (bug #16308). This fix makes the dynamic cast evaluator ignore
incomplete types, as they can never be used in a dynamic_cast. Also adding a
regression test.
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1006
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184403 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Core/Store.cpp b/lib/StaticAnalyzer/Core/Store.cpp
index 690ed08..0beb9db 100644
--- a/lib/StaticAnalyzer/Core/Store.cpp
+++ b/lib/StaticAnalyzer/Core/Store.cpp
@@ -325,7 +325,10 @@
if (MRClass == TargetClass)
return loc::MemRegionVal(MR);
- if (!TargetType->isVoidType()) {
+ // We skip over incomplete types. They must be the result of an earlier
+ // reinterpret_cast, as one can only dynamic_cast between types in the same
+ // class hierarchy.
+ if (!TargetType->isVoidType() && MRClass->hasDefinition()) {
// Static upcasts are marked as DerivedToBase casts by Sema, so this will
// only happen when multiple or virtual inheritance is involved.
CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/true,
diff --git a/test/Analysis/derived-to-base.cpp b/test/Analysis/derived-to-base.cpp
index 0664189..e9c7ca8 100644
--- a/test/Analysis/derived-to-base.cpp
+++ b/test/Analysis/derived-to-base.cpp
@@ -450,3 +450,28 @@
}
};
+namespace Bug16309 {
+ struct Incomplete;
+
+ struct Base { virtual ~Base(); };
+
+ struct Derived : public Base { int x; };
+
+ void* f(Incomplete *i) {
+ Base *b = reinterpret_cast<Base *>(i);
+ // This used to crash because of the reinterpret_cast above.
+ Derived *d = dynamic_cast<Derived *>(b);
+ return d;
+ }
+
+ // And check that reinterpret+dynamic casts work correctly after the fix.
+ void g() {
+ Derived d;
+ d.x = 47;
+ Base *b = &d;
+ Incomplete *i = reinterpret_cast<Incomplete *>(b);
+ Base *b2 = reinterpret_cast<Base *>(i);
+ Derived *d2 = dynamic_cast<Derived *>(b2);
+ clang_analyzer_eval(d2->x == 47); // expected-warning{{TRUE}}
+ }
+}
