https://github.com/t-rasmud updated
https://github.com/llvm/llvm-project/pull/114606
>From cc19550fdbaca4b77e90de57c472a31a8c3f8293 Mon Sep 17 00:00:00 2001
From: Rashmi Mudduluru <r_muddul...@apple.com>
Date: Fri, 1 Nov 2024 14:10:50 -0700
Subject: [PATCH 1/5] [Webkit Checkers] Introduce a Webkit checker for memory
unsafe casts
The checker warns all downcasts from a base type to a derived type.
rdar://137766829
---
clang/docs/analyzer/checkers.rst | 25 +++
clang/docs/tools/clang-formatted-files.txt | 1 +
.../clang/StaticAnalyzer/Checkers/Checkers.td | 4 +
.../StaticAnalyzer/Checkers/CMakeLists.txt | 1 +
.../WebKit/MemoryUnsafeCastChecker.cpp | 86 ++++++++++
.../Checkers/WebKit/memory-unsafe-cast.cpp | 151 ++++++++++++++++++
.../Checkers/WebKit/memory-unsafe-cast.mm | 29 ++++
7 files changed, 297 insertions(+)
create mode 100644
clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
create mode 100644 clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
create mode 100644 clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
diff --git a/clang/docs/analyzer/checkers.rst b/clang/docs/analyzer/checkers.rst
index 87b03438e6e0b9..f01755ce7a236a 100644
--- a/clang/docs/analyzer/checkers.rst
+++ b/clang/docs/analyzer/checkers.rst
@@ -3452,6 +3452,31 @@ alpha.WebKit
.. _alpha-webkit-NoUncheckedPtrMemberChecker:
+alpha.webkit.MemoryUnsafeCastChecker
+""""""""""""""""""""""""""""""""""""""
+Check for all casts from a base type to its derived type as these might be
memory-unsafe.
+
+Example:
+
+.. code-block:: cpp
+
+class Base { };
+class Derived : public Base { };
+
+void f(Base* base) {
+ Derived* derived = static_cast<Derived*>(base); // ERROR
+}
+
+For all cast operations (C-style casts, static_cast, reinterpret_cast,
dynamic_cast), if the source type a `Base*` and the destination type is
`Derived*`, where `Derived` inherits from `Base`, the static analyzer should
signal an error.
+
+This applies to:
+
+- C structs, C++ structs and classes, and Objective-C classes and protocols.
+- Pointers and references.
+- Inside template instantiations and macro expansions that are visible to the
compiler.
+
+For types like this, instead of using built in casts, the programmer will use
helper functions that internally perform the appropriate type check and disable
static analysis.
+
alpha.webkit.NoUncheckedPtrMemberChecker
""""""""""""""""""""""""""""""""""""""""
Raw pointers and references to an object which supports CheckedPtr or
CheckedRef can't be used as class members. Only CheckedPtr, CheckedRef, RefPtr,
or Ref are allowed.
diff --git a/clang/docs/tools/clang-formatted-files.txt
b/clang/docs/tools/clang-formatted-files.txt
index 67ff085144f4de..74ab155d6174fd 100644
--- a/clang/docs/tools/clang-formatted-files.txt
+++ b/clang/docs/tools/clang-formatted-files.txt
@@ -537,6 +537,7 @@
clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp
clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.h
clang/lib/StaticAnalyzer/Checkers/WebKit/DiagOutputUtils.h
+clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.h
clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
diff --git a/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
b/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
index 9a6b35c1b9f774..445379e88ab9e3 100644
--- a/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
+++ b/clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
@@ -1752,6 +1752,10 @@ def UncountedLambdaCapturesChecker :
Checker<"UncountedLambdaCapturesChecker">,
let ParentPackage = WebKitAlpha in {
+def MemoryUnsafeCastChecker : Checker<"MemoryUnsafeCastChecker">,
+ HelpText<"Check for memory unsafe casts from base type to derived type.">,
+ Documentation<HasDocumentation>;
+
def NoUncheckedPtrMemberChecker : Checker<"NoUncheckedPtrMemberChecker">,
HelpText<"Check for no unchecked member variables.">,
Documentation<HasDocumentation>;
diff --git a/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
b/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
index 62aa5ff7f002a9..7e987740f9ee2d 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
+++ b/clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
@@ -132,6 +132,7 @@ add_clang_library(clangStaticAnalyzerCheckers
VirtualCallChecker.cpp
WebKit/RawPtrRefMemberChecker.cpp
WebKit/ASTUtils.cpp
+ WebKit/MemoryUnsafeCastChecker.cpp
WebKit/PtrTypesSemantics.cpp
WebKit/RefCntblBaseVirtualDtorChecker.cpp
WebKit/UncountedCallArgsChecker.cpp
diff --git
a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
new file mode 100644
index 00000000000000..05a5f89d28c8fe
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
@@ -0,0 +1,86 @@
+//=======- MemoryUnsafeCastChecker.cpp -------------------------*- C++ -*-==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM
Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines MemoryUnsafeCast checker, which checks for casts from a
+// base type to a derived type.
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/ASTContext.h"
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class MemoryUnsafeCastChecker : public Checker<check::PreStmt<CastExpr>> {
+ BugType BT{this, ""};
+
+public:
+ void checkPreStmt(const CastExpr *CE, CheckerContext &C) const;
+};
+} // end namespace
+
+void emitWarning(CheckerContext &C, const CastExpr &CE, const BugType &BT,
+ QualType FromType, QualType ToType) {
+ ExplodedNode *errorNode = C.generateNonFatalErrorNode();
+ if (!errorNode)
+ return;
+ SmallString<192> Buf;
+ llvm::raw_svector_ostream OS(Buf);
+ OS << "Memory unsafe cast from base type '";
+ QualType::print(FromType.getTypePtr(), Qualifiers(), OS, C.getLangOpts(),
+ llvm::Twine());
+ OS << "' to derived type '";
+ QualType::print(ToType.getTypePtr(), Qualifiers(), OS, C.getLangOpts(),
+ llvm::Twine());
+ OS << "'";
+ auto R = std::make_unique<PathSensitiveBugReport>(BT, OS.str(), errorNode);
+ R->addRange(CE.getSourceRange());
+ C.emitReport(std::move(R));
+}
+
+void MemoryUnsafeCastChecker::checkPreStmt(const CastExpr *CE,
+ CheckerContext &C) const {
+ auto ExpCast = dyn_cast_or_null<ExplicitCastExpr>(CE);
+ if (!ExpCast)
+ return;
+
+ auto ToDerivedQualType = ExpCast->getTypeAsWritten();
+ auto *SE = CE->getSubExprAsWritten();
+ if (ToDerivedQualType->isObjCObjectPointerType()) {
+ auto FromBaseQualType = SE->getType();
+ bool IsObjCSubType =
+ !C.getASTContext().hasSameType(ToDerivedQualType, FromBaseQualType) &&
+ C.getASTContext().canAssignObjCInterfaces(
+ FromBaseQualType->getAsObjCInterfacePointerType(),
+ ToDerivedQualType->getAsObjCInterfacePointerType());
+ if (IsObjCSubType)
+ emitWarning(C, *CE, BT, FromBaseQualType, ToDerivedQualType);
+ return;
+ }
+ auto ToDerivedType = ToDerivedQualType->getPointeeCXXRecordDecl();
+ auto FromBaseType = SE->getType()->getPointeeCXXRecordDecl();
+ if (!FromBaseType)
+ FromBaseType = SE->getType()->getAsCXXRecordDecl();
+ if (!FromBaseType)
+ return;
+ if (ToDerivedType->isDerivedFrom(FromBaseType))
+ emitWarning(C, *CE, BT, SE->getType(), ToDerivedQualType);
+}
+
+void ento::registerMemoryUnsafeCastChecker(CheckerManager &Mgr) {
+ Mgr.registerChecker<MemoryUnsafeCastChecker>();
+}
+
+bool ento::shouldRegisterMemoryUnsafeCastChecker(const CheckerManager &) {
+ return true;
+}
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
new file mode 100644
index 00000000000000..1a4ef6858d2180
--- /dev/null
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
@@ -0,0 +1,151 @@
+// RUN: %clang_analyze_cc1
-analyzer-checker=alpha.webkit.MemoryUnsafeCastChecker -verify %s
+
+class Base { };
+class Derived : public Base { };
+
+void test_pointers(Base *base) {
+ Derived *derived_static = static_cast<Derived*>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ Derived *derived_reinterpret = reinterpret_cast<Derived*>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ Derived *derived_c = (Derived*)base;
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+}
+
+void test_refs(Base &base) {
+ Derived &derived_static = static_cast<Derived&>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ Derived &derived_reinterpret = reinterpret_cast<Derived&>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ Derived &derived_c = (Derived&)base;
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+}
+
+class BaseVirtual {
+ virtual void virtual_base_function();
+};
+
+class DerivedVirtual : public BaseVirtual {
+ void virtual_base_function() override { }
+};
+
+void test_dynamic_casts(BaseVirtual *base_ptr, BaseVirtual &base_ref) {
+ DerivedVirtual *derived_dynamic_ptr =
dynamic_cast<DerivedVirtual*>(base_ptr);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseVirtual *' to
derived type 'DerivedVirtual *'}}
+ DerivedVirtual &derived_dynamic_ref =
dynamic_cast<DerivedVirtual&>(base_ref);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseVirtual' to
derived type 'DerivedVirtual &'}}
+}
+
+struct BaseStruct { };
+struct DerivedStruct : BaseStruct { };
+
+void test_struct_pointers(struct BaseStruct *base_struct) {
+ struct DerivedStruct *derived_static = static_cast<struct
DerivedStruct*>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'struct BaseStruct
*' to derived type 'struct DerivedStruct *'}}
+ struct DerivedStruct *derived_reinterpret = reinterpret_cast<struct
DerivedStruct*>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'struct BaseStruct
*' to derived type 'struct DerivedStruct *'}}
+ struct DerivedStruct *derived_c = (struct DerivedStruct*)base_struct;
+ // expected-warning@-1{{Memory unsafe cast from base type 'struct BaseStruct
*' to derived type 'struct DerivedStruct *'}}
+}
+
+typedef struct BaseStruct BStruct;
+typedef struct DerivedStruct DStruct;
+
+void test_struct_refs(BStruct &base_struct) {
+ DStruct &derived_static = static_cast<DStruct&>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+ DStruct &derived_reinterpret = reinterpret_cast<DStruct&>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+ DStruct &derived_c = (DStruct&)base_struct;
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+}
+
+int counter = 0;
+void test_recursive(BStruct &base_struct) {
+ if (counter == 5)
+ return;
+ counter++;
+ DStruct &derived_static = static_cast<DStruct&>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+}
+
+template<typename T>
+class BaseTemplate { };
+
+template<typename T>
+class DerivedTemplate : public BaseTemplate<T> { };
+
+void test_templates(BaseTemplate<int> *base, BaseTemplate<int> &base_ref) {
+ DerivedTemplate<int> *derived_static =
static_cast<DerivedTemplate<int>*>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseTemplate<int>
*' to derived type 'DerivedTemplate<int> *'}}
+ DerivedTemplate<int> *derived_reinterpret =
reinterpret_cast<DerivedTemplate<int>*>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseTemplate<int>
*' to derived type 'DerivedTemplate<int> *'}}
+ DerivedTemplate<int> *derived_c = (DerivedTemplate<int>*)base;
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseTemplate<int>
*' to derived type 'DerivedTemplate<int> *'}}
+ DerivedTemplate<int> &derived_static_ref =
static_cast<DerivedTemplate<int>&>(base_ref);
+ // expected-warning@-1{{Memory unsafe cast from base type
'BaseTemplate<int>' to derived type 'DerivedTemplate<int> &'}}
+ DerivedTemplate<int> &derived_reinterpret_ref =
reinterpret_cast<DerivedTemplate<int>&>(base_ref);
+ // expected-warning@-1{{Memory unsafe cast from base type
'BaseTemplate<int>' to derived type 'DerivedTemplate<int> &'}}
+ DerivedTemplate<int> &derived_c_ref = (DerivedTemplate<int>&)base_ref;
+ // expected-warning@-1{{Memory unsafe cast from base type
'BaseTemplate<int>' to derived type 'DerivedTemplate<int> &'}}
+}
+
+#define CAST_MACRO_STATIC(X,Y) (static_cast<Y>(X))
+#define CAST_MACRO_REINTERPRET(X,Y) (reinterpret_cast<Y>(X))
+#define CAST_MACRO_C(X,Y) ((Y)X)
+
+void test_macro_static(Base *base, Derived *derived, Base &base_ref) {
+ Derived *derived_static = CAST_MACRO_STATIC(base, Derived*);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ Derived &derived_static_ref = CAST_MACRO_STATIC(base_ref, Derived&);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ Base *base_static_same = CAST_MACRO_STATIC(base, Base*); // no warning
+ Base *base_static_upcast = CAST_MACRO_STATIC(derived, Base*); // no warning
+}
+
+void test_macro_reinterpret(Base *base, Derived *derived, Base &base_ref) {
+ Derived *derived_reinterpret = CAST_MACRO_REINTERPRET(base, Derived*);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ Derived &derived_reinterpret_ref = CAST_MACRO_REINTERPRET(base_ref,
Derived&);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &' [alpha.webkit.MemoryUnsafeCastChecker]}}
+ Base *base_reinterpret_same = CAST_MACRO_REINTERPRET(base, Base*); // no
warning
+ Base *base_reinterpret_upcast = CAST_MACRO_REINTERPRET(derived, Base*); //
no warning
+}
+
+void test_macro_c(Base *base, Derived *derived, Base &base_ref) {
+ Derived *derived_c = CAST_MACRO_C(base, Derived*);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *' [alpha.webkit.MemoryUnsafeCastChecker]}}
+ Derived &derived_c_ref = CAST_MACRO_C(base_ref, Derived&);
+ // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &' [alpha.webkit.MemoryUnsafeCastChecker]}}
+ Base *base_c_same = CAST_MACRO_C(base, Base*); // no warning
+ Base *base_c_upcast = CAST_MACRO_C(derived, Base*); // no warning
+}
+
+struct BaseStructCpp {
+ int t;
+ void increment() { t++; }
+};
+struct DerivedStructCpp : BaseStructCpp {
+ void increment_t() {increment();}
+};
+
+void test_struct_cpp_pointers(struct BaseStructCpp *base_struct) {
+ struct DerivedStructCpp *derived_static = static_cast<struct
DerivedStructCpp*>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'struct
BaseStructCpp *' to derived type 'struct DerivedStructCpp *'}}
+ struct DerivedStructCpp *derived_reinterpret = reinterpret_cast<struct
DerivedStructCpp*>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'struct
BaseStructCpp *' to derived type 'struct DerivedStructCpp *'}}
+ struct DerivedStructCpp *derived_c = (struct DerivedStructCpp*)base_struct;
+ // expected-warning@-1{{Memory unsafe cast from base type 'struct
BaseStructCpp *' to derived type 'struct DerivedStructCpp *'}}
+}
+
+typedef struct BaseStructCpp BStructCpp;
+typedef struct DerivedStructCpp DStructCpp;
+
+void test_struct_cpp_refs(BStructCpp &base_struct) {
+ DStructCpp &derived_static = static_cast<DStructCpp&>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStructCpp' to
derived type 'DStructCpp &'}}
+ DStructCpp &derived_reinterpret = reinterpret_cast<DStructCpp&>(base_struct);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStructCpp' to
derived type 'DStructCpp &'}}
+ DStructCpp &derived_c = (DStructCpp&)base_struct;
+ // expected-warning@-1{{Memory unsafe cast from base type 'BStructCpp' to
derived type 'DStructCpp &'}}
+}
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
new file mode 100644
index 00000000000000..1ea2f4aa472715
--- /dev/null
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
@@ -0,0 +1,29 @@
+// RUN: %clang_analyze_cc1
-analyzer-checker=alpha.webkit.MemoryUnsafeCastChecker -verify %s
+
+@protocol NSObject
++alloc;
+-init;
+@end
+
+@interface NSObject <NSObject> {}
+@end
+
+@interface BaseClass : NSObject
+@end
+
+@interface DerivedClass : BaseClass
+-(void)testCasts:(BaseClass*)base;
+@end
+
+@implementation DerivedClass
+-(void)testCasts:(BaseClass*)base {
+ DerivedClass *derived = (DerivedClass*)base;
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseClass *' to
derived type 'DerivedClass *'}}
+ DerivedClass *derived_static = static_cast<DerivedClass*>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseClass *' to
derived type 'DerivedClass *'}}
+ DerivedClass *derived_reinterpret = reinterpret_cast<DerivedClass*>(base);
+ // expected-warning@-1{{Memory unsafe cast from base type 'BaseClass *' to
derived type 'DerivedClass *'}}
+ base = (BaseClass*)derived; // no warning
+ base = (BaseClass*)base; // no warning
+}
+@end
>From eece6157a062e76bec376beb2aada1edbb3199e7 Mon Sep 17 00:00:00 2001
From: Rashmi Mudduluru <r_muddul...@apple.com>
Date: Tue, 5 Nov 2024 10:59:22 -0800
Subject: [PATCH 2/5] Address comments: fix tests, make checker
path-insensitive
---
.../WebKit/MemoryUnsafeCastChecker.cpp | 95 ++++++++++++-------
.../Checkers/WebKit/memory-unsafe-cast.cpp | 71 +++++++-------
.../Checkers/WebKit/memory-unsafe-cast.mm | 6 +-
3 files changed, 103 insertions(+), 69 deletions(-)
diff --git
a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
index 05a5f89d28c8fe..b5d1e0d810c610 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
@@ -10,46 +10,71 @@
// base type to a derived type.
//===----------------------------------------------------------------------===//
-#include "clang/AST/ASTContext.h"
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Analysis/AnalysisDeclContext.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
-#include "clang/StaticAnalyzer/Core/CheckerManager.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
using namespace clang;
using namespace ento;
namespace {
-class MemoryUnsafeCastChecker : public Checker<check::PreStmt<CastExpr>> {
- BugType BT{this, ""};
+class WalkAST : public StmtVisitor<WalkAST> {
+ BugReporter &BR;
+ const CheckerBase *Checker;
+ AnalysisDeclContext* AC;
+ ASTContext &ASTC;
public:
- void checkPreStmt(const CastExpr *CE, CheckerContext &C) const;
+ WalkAST(BugReporter &br, const CheckerBase *checker, AnalysisDeclContext *ac)
+ : BR(br), Checker(checker), AC(ac), ASTC(AC->getASTContext()) {}
+
+ // Statement visitor methods.
+ void VisitChildren(Stmt *S);
+ void VisitStmt(Stmt *S) { VisitChildren(S); }
+ void VisitCastExpr(CastExpr *CE);
};
-} // end namespace
+} // end anonymous namespace
-void emitWarning(CheckerContext &C, const CastExpr &CE, const BugType &BT,
- QualType FromType, QualType ToType) {
- ExplodedNode *errorNode = C.generateNonFatalErrorNode();
- if (!errorNode)
- return;
- SmallString<192> Buf;
- llvm::raw_svector_ostream OS(Buf);
- OS << "Memory unsafe cast from base type '";
- QualType::print(FromType.getTypePtr(), Qualifiers(), OS, C.getLangOpts(),
- llvm::Twine());
- OS << "' to derived type '";
- QualType::print(ToType.getTypePtr(), Qualifiers(), OS, C.getLangOpts(),
- llvm::Twine());
- OS << "'";
- auto R = std::make_unique<PathSensitiveBugReport>(BT, OS.str(), errorNode);
- R->addRange(CE.getSourceRange());
- C.emitReport(std::move(R));
+void emitWarning(QualType FromType, QualType ToType,
+ AnalysisDeclContext *AC, BugReporter &BR,
+ const CheckerBase *Checker,
+ CastExpr *CE) {
+ std::string Diagnostics;
+ llvm::raw_string_ostream OS(Diagnostics);
+ OS << "Unsafe cast from base type '"
+ << FromType
+ << "' to derived type '"
+ << ToType
+ << "'",
+
+ BR.EmitBasicReport(
+ AC->getDecl(),
+ Checker,
+ /*Name=*/"Memory unsafe cast",
+ categories::SecurityError,
+ Diagnostics,
+ PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC),
+ CE->getSourceRange());
}
-void MemoryUnsafeCastChecker::checkPreStmt(const CastExpr *CE,
- CheckerContext &C) const {
+namespace {
+class MemoryUnsafeCastChecker : public Checker<check::ASTCodeBody> {
+ BugType BT{this, ""};
+public:
+ void checkASTCodeBody(const Decl *D, AnalysisManager& Mgr,
+ BugReporter &BR) const {
+ WalkAST walker(BR, this, Mgr.getAnalysisDeclContext(D));
+ walker.Visit(D->getBody());
+ }
+};
+}
+
+void WalkAST::VisitCastExpr(CastExpr *CE) {
auto ExpCast = dyn_cast_or_null<ExplicitCastExpr>(CE);
if (!ExpCast)
return;
@@ -59,12 +84,12 @@ void MemoryUnsafeCastChecker::checkPreStmt(const CastExpr
*CE,
if (ToDerivedQualType->isObjCObjectPointerType()) {
auto FromBaseQualType = SE->getType();
bool IsObjCSubType =
- !C.getASTContext().hasSameType(ToDerivedQualType, FromBaseQualType) &&
- C.getASTContext().canAssignObjCInterfaces(
+ !ASTC.hasSameType(ToDerivedQualType, FromBaseQualType) &&
+ ASTC.canAssignObjCInterfaces(
FromBaseQualType->getAsObjCInterfacePointerType(),
ToDerivedQualType->getAsObjCInterfacePointerType());
if (IsObjCSubType)
- emitWarning(C, *CE, BT, FromBaseQualType, ToDerivedQualType);
+ emitWarning(SE->getType(), ToDerivedQualType,AC, BR, Checker, CE);
return;
}
auto ToDerivedType = ToDerivedQualType->getPointeeCXXRecordDecl();
@@ -74,13 +99,19 @@ void MemoryUnsafeCastChecker::checkPreStmt(const CastExpr
*CE,
if (!FromBaseType)
return;
if (ToDerivedType->isDerivedFrom(FromBaseType))
- emitWarning(C, *CE, BT, SE->getType(), ToDerivedQualType);
+ emitWarning(SE->getType(), ToDerivedQualType, AC, BR, Checker, CE);
+}
+
+void WalkAST::VisitChildren(Stmt *S) {
+ for (Stmt *Child : S->children())
+ if (Child)
+ Visit(Child);
}
void ento::registerMemoryUnsafeCastChecker(CheckerManager &Mgr) {
Mgr.registerChecker<MemoryUnsafeCastChecker>();
}
-bool ento::shouldRegisterMemoryUnsafeCastChecker(const CheckerManager &) {
+bool ento::shouldRegisterMemoryUnsafeCastChecker(const CheckerManager &mgr) {
return true;
}
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
index 1a4ef6858d2180..ed58ac4ae0d5b7 100644
--- a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
@@ -5,20 +5,20 @@ class Derived : public Base { };
void test_pointers(Base *base) {
Derived *derived_static = static_cast<Derived*>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
Derived *derived_reinterpret = reinterpret_cast<Derived*>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
Derived *derived_c = (Derived*)base;
- // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
}
void test_refs(Base &base) {
Derived &derived_static = static_cast<Derived&>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &'}}
Derived &derived_reinterpret = reinterpret_cast<Derived&>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &'}}
Derived &derived_c = (Derived&)base;
- // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &'}}
}
class BaseVirtual {
@@ -31,9 +31,9 @@ class DerivedVirtual : public BaseVirtual {
void test_dynamic_casts(BaseVirtual *base_ptr, BaseVirtual &base_ref) {
DerivedVirtual *derived_dynamic_ptr =
dynamic_cast<DerivedVirtual*>(base_ptr);
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseVirtual *' to
derived type 'DerivedVirtual *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseVirtual *' to
derived type 'DerivedVirtual *'}}
DerivedVirtual &derived_dynamic_ref =
dynamic_cast<DerivedVirtual&>(base_ref);
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseVirtual' to
derived type 'DerivedVirtual &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseVirtual' to derived
type 'DerivedVirtual &'}}
}
struct BaseStruct { };
@@ -41,11 +41,11 @@ struct DerivedStruct : BaseStruct { };
void test_struct_pointers(struct BaseStruct *base_struct) {
struct DerivedStruct *derived_static = static_cast<struct
DerivedStruct*>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'struct BaseStruct
*' to derived type 'struct DerivedStruct *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'struct BaseStruct *' to
derived type 'struct DerivedStruct *'}}
struct DerivedStruct *derived_reinterpret = reinterpret_cast<struct
DerivedStruct*>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'struct BaseStruct
*' to derived type 'struct DerivedStruct *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'struct BaseStruct *' to
derived type 'struct DerivedStruct *'}}
struct DerivedStruct *derived_c = (struct DerivedStruct*)base_struct;
- // expected-warning@-1{{Memory unsafe cast from base type 'struct BaseStruct
*' to derived type 'struct DerivedStruct *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'struct BaseStruct *' to
derived type 'struct DerivedStruct *'}}
}
typedef struct BaseStruct BStruct;
@@ -53,11 +53,11 @@ typedef struct DerivedStruct DStruct;
void test_struct_refs(BStruct &base_struct) {
DStruct &derived_static = static_cast<DStruct&>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStruct' to derived type
'DStruct &'}}
DStruct &derived_reinterpret = reinterpret_cast<DStruct&>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStruct' to derived type
'DStruct &'}}
DStruct &derived_c = (DStruct&)base_struct;
- // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStruct' to derived type
'DStruct &'}}
}
int counter = 0;
@@ -66,7 +66,7 @@ void test_recursive(BStruct &base_struct) {
return;
counter++;
DStruct &derived_static = static_cast<DStruct&>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'BStruct' to
derived type 'DStruct &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStruct' to derived type
'DStruct &'}}
}
template<typename T>
@@ -77,17 +77,17 @@ class DerivedTemplate : public BaseTemplate<T> { };
void test_templates(BaseTemplate<int> *base, BaseTemplate<int> &base_ref) {
DerivedTemplate<int> *derived_static =
static_cast<DerivedTemplate<int>*>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseTemplate<int>
*' to derived type 'DerivedTemplate<int> *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseTemplate<int> *' to
derived type 'DerivedTemplate<int> *'}}
DerivedTemplate<int> *derived_reinterpret =
reinterpret_cast<DerivedTemplate<int>*>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseTemplate<int>
*' to derived type 'DerivedTemplate<int> *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseTemplate<int> *' to
derived type 'DerivedTemplate<int> *'}}
DerivedTemplate<int> *derived_c = (DerivedTemplate<int>*)base;
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseTemplate<int>
*' to derived type 'DerivedTemplate<int> *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseTemplate<int> *' to
derived type 'DerivedTemplate<int> *'}}
DerivedTemplate<int> &derived_static_ref =
static_cast<DerivedTemplate<int>&>(base_ref);
- // expected-warning@-1{{Memory unsafe cast from base type
'BaseTemplate<int>' to derived type 'DerivedTemplate<int> &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseTemplate<int>' to
derived type 'DerivedTemplate<int> &'}}
DerivedTemplate<int> &derived_reinterpret_ref =
reinterpret_cast<DerivedTemplate<int>&>(base_ref);
- // expected-warning@-1{{Memory unsafe cast from base type
'BaseTemplate<int>' to derived type 'DerivedTemplate<int> &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseTemplate<int>' to
derived type 'DerivedTemplate<int> &'}}
DerivedTemplate<int> &derived_c_ref = (DerivedTemplate<int>&)base_ref;
- // expected-warning@-1{{Memory unsafe cast from base type
'BaseTemplate<int>' to derived type 'DerivedTemplate<int> &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseTemplate<int>' to
derived type 'DerivedTemplate<int> &'}}
}
#define CAST_MACRO_STATIC(X,Y) (static_cast<Y>(X))
@@ -96,27 +96,27 @@ void test_templates(BaseTemplate<int> *base,
BaseTemplate<int> &base_ref) {
void test_macro_static(Base *base, Derived *derived, Base &base_ref) {
Derived *derived_static = CAST_MACRO_STATIC(base, Derived*);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
Derived &derived_static_ref = CAST_MACRO_STATIC(base_ref, Derived&);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &'}}
Base *base_static_same = CAST_MACRO_STATIC(base, Base*); // no warning
Base *base_static_upcast = CAST_MACRO_STATIC(derived, Base*); // no warning
}
void test_macro_reinterpret(Base *base, Derived *derived, Base &base_ref) {
Derived *derived_reinterpret = CAST_MACRO_REINTERPRET(base, Derived*);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
Derived &derived_reinterpret_ref = CAST_MACRO_REINTERPRET(base_ref,
Derived&);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &' [alpha.webkit.MemoryUnsafeCastChecker]}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &' [alpha.webkit.MemoryUnsafeCastChecker]}}
Base *base_reinterpret_same = CAST_MACRO_REINTERPRET(base, Base*); // no
warning
Base *base_reinterpret_upcast = CAST_MACRO_REINTERPRET(derived, Base*); //
no warning
}
void test_macro_c(Base *base, Derived *derived, Base &base_ref) {
Derived *derived_c = CAST_MACRO_C(base, Derived*);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base *' to
derived type 'Derived *' [alpha.webkit.MemoryUnsafeCastChecker]}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *' [alpha.webkit.MemoryUnsafeCastChecker]}}
Derived &derived_c_ref = CAST_MACRO_C(base_ref, Derived&);
- // expected-warning@-1{{Memory unsafe cast from base type 'Base' to derived
type 'Derived &' [alpha.webkit.MemoryUnsafeCastChecker]}}
+ // expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &' [alpha.webkit.MemoryUnsafeCastChecker]}}
Base *base_c_same = CAST_MACRO_C(base, Base*); // no warning
Base *base_c_upcast = CAST_MACRO_C(derived, Base*); // no warning
}
@@ -131,21 +131,24 @@ struct DerivedStructCpp : BaseStructCpp {
void test_struct_cpp_pointers(struct BaseStructCpp *base_struct) {
struct DerivedStructCpp *derived_static = static_cast<struct
DerivedStructCpp*>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'struct
BaseStructCpp *' to derived type 'struct DerivedStructCpp *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'struct BaseStructCpp *'
to derived type 'struct DerivedStructCpp *'}}
struct DerivedStructCpp *derived_reinterpret = reinterpret_cast<struct
DerivedStructCpp*>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'struct
BaseStructCpp *' to derived type 'struct DerivedStructCpp *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'struct BaseStructCpp *'
to derived type 'struct DerivedStructCpp *'}}
struct DerivedStructCpp *derived_c = (struct DerivedStructCpp*)base_struct;
- // expected-warning@-1{{Memory unsafe cast from base type 'struct
BaseStructCpp *' to derived type 'struct DerivedStructCpp *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'struct BaseStructCpp *'
to derived type 'struct DerivedStructCpp *'}}
}
typedef struct BaseStructCpp BStructCpp;
typedef struct DerivedStructCpp DStructCpp;
-void test_struct_cpp_refs(BStructCpp &base_struct) {
+void test_struct_cpp_refs(BStructCpp &base_struct, DStructCpp &derived_struct)
{
DStructCpp &derived_static = static_cast<DStructCpp&>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'BStructCpp' to
derived type 'DStructCpp &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStructCpp' to derived
type 'DStructCpp &'}}
DStructCpp &derived_reinterpret = reinterpret_cast<DStructCpp&>(base_struct);
- // expected-warning@-1{{Memory unsafe cast from base type 'BStructCpp' to
derived type 'DStructCpp &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStructCpp' to derived
type 'DStructCpp &'}}
DStructCpp &derived_c = (DStructCpp&)base_struct;
- // expected-warning@-1{{Memory unsafe cast from base type 'BStructCpp' to
derived type 'DStructCpp &'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BStructCpp' to derived
type 'DStructCpp &'}}
+ BStructCpp &base = (BStructCpp&)derived_struct; // no warning
+ BStructCpp &base_static = static_cast<BStructCpp&>(derived_struct); // no
warning
+ BStructCpp &base_reinterpret =
reinterpret_cast<BStructCpp&>(derived_struct); // no warning
}
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
index 1ea2f4aa472715..61f2fffd43fbda 100644
--- a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
@@ -18,11 +18,11 @@ -(void)testCasts:(BaseClass*)base;
@implementation DerivedClass
-(void)testCasts:(BaseClass*)base {
DerivedClass *derived = (DerivedClass*)base;
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseClass *' to
derived type 'DerivedClass *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseClass *' to derived
type 'DerivedClass *'}}
DerivedClass *derived_static = static_cast<DerivedClass*>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseClass *' to
derived type 'DerivedClass *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseClass *' to derived
type 'DerivedClass *'}}
DerivedClass *derived_reinterpret = reinterpret_cast<DerivedClass*>(base);
- // expected-warning@-1{{Memory unsafe cast from base type 'BaseClass *' to
derived type 'DerivedClass *'}}
+ // expected-warning@-1{{Unsafe cast from base type 'BaseClass *' to derived
type 'DerivedClass *'}}
base = (BaseClass*)derived; // no warning
base = (BaseClass*)base; // no warning
}
>From 8e30c93bd7a9175f04cae658bb89ffa149b8b256 Mon Sep 17 00:00:00 2001
From: Rashmi Mudduluru <r_muddul...@apple.com>
Date: Wed, 6 Nov 2024 10:56:48 -0800
Subject: [PATCH 3/5] Add tests: define downcast and ensure no warning
---
.../Checkers/WebKit/memory-unsafe-cast.cpp | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
index ed58ac4ae0d5b7..72a054d0652d7d 100644
--- a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
@@ -3,6 +3,18 @@
class Base { };
class Derived : public Base { };
+template<typename Target, typename Source>
+Target& downcast_ref(Source& source){
+ [[clang::suppress]]
+ return static_cast<Target&>(source);
+}
+
+template<typename Target, typename Source>
+Target* downcast_ptr(Source* source){
+ [[clang::suppress]]
+ return static_cast<Target*>(source);
+}
+
void test_pointers(Base *base) {
Derived *derived_static = static_cast<Derived*>(base);
// expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
@@ -10,6 +22,7 @@ void test_pointers(Base *base) {
// expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
Derived *derived_c = (Derived*)base;
// expected-warning@-1{{Unsafe cast from base type 'Base *' to derived type
'Derived *'}}
+ Derived *derived_d = downcast_ptr<Derived, Base>(base); // no warning
}
void test_refs(Base &base) {
@@ -19,6 +32,7 @@ void test_refs(Base &base) {
// expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &'}}
Derived &derived_c = (Derived&)base;
// expected-warning@-1{{Unsafe cast from base type 'Base' to derived type
'Derived &'}}
+ Derived &derived_d = downcast_ref<Derived, Base>(base); // no warning
}
class BaseVirtual {
>From 073abfca2c856b4d19fc65da1dcc51088d4b3a31 Mon Sep 17 00:00:00 2001
From: Rashmi Mudduluru <r_muddul...@apple.com>
Date: Thu, 7 Nov 2024 15:41:50 -0800
Subject: [PATCH 4/5] Fix crashes and add corresponding reproducer test cases
---
.../WebKit/MemoryUnsafeCastChecker.cpp | 21 +++++++++++-----
.../Checkers/WebKit/memory-unsafe-cast.cpp | 8 +++++++
.../Checkers/WebKit/memory-unsafe-cast.mm | 24 +++++++++++++++++++
3 files changed, 47 insertions(+), 6 deletions(-)
diff --git
a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
index b5d1e0d810c610..ff659c0e4af18f 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
@@ -64,7 +64,7 @@ void emitWarning(QualType FromType, QualType ToType,
namespace {
class MemoryUnsafeCastChecker : public Checker<check::ASTCodeBody> {
- BugType BT{this, ""};
+ BugType BT{this, "Unsafe cast", "WebKit coding guidelines"};
public:
void checkASTCodeBody(const Decl *D, AnalysisManager& Mgr,
BugReporter &BR) const {
@@ -83,21 +83,30 @@ void WalkAST::VisitCastExpr(CastExpr *CE) {
auto *SE = CE->getSubExprAsWritten();
if (ToDerivedQualType->isObjCObjectPointerType()) {
auto FromBaseQualType = SE->getType();
+ auto BaseObjCPtrType = FromBaseQualType->getAsObjCInterfacePointerType();
+ if (!BaseObjCPtrType)
+ return;
+ auto DerivedObjCPtrType =
ToDerivedQualType->getAsObjCInterfacePointerType();
+ if (!DerivedObjCPtrType)
+ return;
bool IsObjCSubType =
!ASTC.hasSameType(ToDerivedQualType, FromBaseQualType) &&
- ASTC.canAssignObjCInterfaces(
- FromBaseQualType->getAsObjCInterfacePointerType(),
- ToDerivedQualType->getAsObjCInterfacePointerType());
+ ASTC.canAssignObjCInterfaces(FromBaseQualType
+ ->getAsObjCInterfacePointerType(),
+ ToDerivedQualType
+ ->getAsObjCInterfacePointerType());
if (IsObjCSubType)
emitWarning(SE->getType(), ToDerivedQualType,AC, BR, Checker, CE);
return;
}
auto ToDerivedType = ToDerivedQualType->getPointeeCXXRecordDecl();
+ if (!ToDerivedType || !ToDerivedType->hasDefinition())
+ return;
auto FromBaseType = SE->getType()->getPointeeCXXRecordDecl();
if (!FromBaseType)
FromBaseType = SE->getType()->getAsCXXRecordDecl();
- if (!FromBaseType)
- return;
+ if (!FromBaseType || !FromBaseType->hasDefinition())
+ return;
if (ToDerivedType->isDerivedFrom(FromBaseType))
emitWarning(SE->getType(), ToDerivedQualType, AC, BR, Checker, CE);
}
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
index 72a054d0652d7d..e59c8fa71ab288 100644
--- a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.cpp
@@ -166,3 +166,11 @@ void test_struct_cpp_refs(BStructCpp &base_struct,
DStructCpp &derived_struct) {
BStructCpp &base_static = static_cast<BStructCpp&>(derived_struct); // no
warning
BStructCpp &base_reinterpret =
reinterpret_cast<BStructCpp&>(derived_struct); // no warning
}
+
+struct stack_st { };
+
+#define STACK_OF(type) struct stack_st_##type
+
+void test_stack(stack_st *base) {
+ STACK_OF(void) *derived = (STACK_OF(void)*)base;
+}
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
index 61f2fffd43fbda..6c49304e1c2c60 100644
--- a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
@@ -27,3 +27,27 @@ -(void)testCasts:(BaseClass*)base {
base = (BaseClass*)base; // no warning
}
@end
+
+template <typename T>
+class WrappedObject
+{
+public:
+ T get() const { return mMetalObject; }
+ T mMetalObject = nullptr;
+};
+
+@protocol MTLCommandEncoder
+@end
+@protocol MTLRenderCommandEncoder
+@end
+class CommandEncoder : public WrappedObject<id<MTLCommandEncoder>> { };
+
+class RenderCommandEncoder final : public CommandEncoder
+{
+private:
+ // Override CommandEncoder
+ id<MTLRenderCommandEncoder> get()
+ {
+ return static_cast<id<MTLRenderCommandEncoder>>(CommandEncoder::get());
+ }
+};
>From e0455cf2ba9fae9cf2ddfb362c5c15fa2351a7af Mon Sep 17 00:00:00 2001
From: Rashmi Mudduluru <r_muddul...@apple.com>
Date: Thu, 7 Nov 2024 16:20:23 -0800
Subject: [PATCH 5/5] Minor fixes
---
.../Checkers/WebKit/MemoryUnsafeCastChecker.cpp | 7 ++-----
clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm | 1 -
2 files changed, 2 insertions(+), 6 deletions(-)
diff --git
a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
index ff659c0e4af18f..289cd4f2736a44 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/MemoryUnsafeCastChecker.cpp
@@ -91,12 +91,9 @@ void WalkAST::VisitCastExpr(CastExpr *CE) {
return;
bool IsObjCSubType =
!ASTC.hasSameType(ToDerivedQualType, FromBaseQualType) &&
- ASTC.canAssignObjCInterfaces(FromBaseQualType
- ->getAsObjCInterfacePointerType(),
- ToDerivedQualType
- ->getAsObjCInterfacePointerType());
+ ASTC.canAssignObjCInterfaces(BaseObjCPtrType, DerivedObjCPtrType);
if (IsObjCSubType)
- emitWarning(SE->getType(), ToDerivedQualType,AC, BR, Checker, CE);
+ emitWarning(SE->getType(), ToDerivedQualType, AC, BR, Checker, CE);
return;
}
auto ToDerivedType = ToDerivedQualType->getPointeeCXXRecordDecl();
diff --git a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
index 6c49304e1c2c60..72dcef7d91fe79 100644
--- a/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
+++ b/clang/test/Analysis/Checkers/WebKit/memory-unsafe-cast.mm
@@ -45,7 +45,6 @@ @protocol MTLRenderCommandEncoder
class RenderCommandEncoder final : public CommandEncoder
{
private:
- // Override CommandEncoder
id<MTLRenderCommandEncoder> get()
{
return static_cast<id<MTLRenderCommandEncoder>>(CommandEncoder::get());
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