https://github.com/rniwa created
https://github.com/llvm/llvm-project/pull/143408
Allow @property of a raw pointer when NS_REQUIRES_PROPERTY_DEFINITIONS is
specified on the interface since such an interface does not automatically
synthesize raw pointer ivars.
Also emit a warning for @property(assign) and @property(unsafe_unretained)
under ARC as well as when explicitly synthesizing a unsafe raw pointer property.
>From 47ed80499d85a6c27a63f414a26c82b2daea817a Mon Sep 17 00:00:00 2001
From: Ryosuke Niwa <rn...@webkit.org>
Date: Fri, 23 May 2025 13:53:36 -0700
Subject: [PATCH] [alpha.webkit.NoUnretainedMemberChecker] Recognize
NS_REQUIRES_PROPERTY_DEFINITIONS
Allow @property of a raw pointer when NS_REQUIRES_PROPERTY_DEFINITIONS is
specified on the interface
since such an interface does not automatically synthesize raw pointer ivars.
Also emit a warning for @property(assign) and @property(unsafe_unretained)
under ARC as well as
when explicitly synthesizing a unsafe raw pointer property.
---
.../Checkers/WebKit/PtrTypesSemantics.cpp | 1 +
.../Checkers/WebKit/PtrTypesSemantics.h | 2 +
.../WebKit/RawPtrRefMemberChecker.cpp | 75 ++++++++++++++++---
.../Checkers/WebKit/objc-mock-types.h | 1 +
.../Checkers/WebKit/unretained-members-arc.mm | 36 +++++++++
.../Checkers/WebKit/unretained-members.mm | 25 +++++++
6 files changed, 129 insertions(+), 11 deletions(-)
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
index cd33476344a34..72199af2f80a5 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
@@ -236,6 +236,7 @@ std::optional<bool> isUnchecked(const QualType T) {
void RetainTypeChecker::visitTranslationUnitDecl(
const TranslationUnitDecl *TUD) {
IsARCEnabled = TUD->getLangOpts().ObjCAutoRefCount;
+ DefaultSynthProperties = TUD->getLangOpts().ObjCDefaultSynthProperties;
}
void RetainTypeChecker::visitTypedef(const TypedefDecl *TD) {
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.h
b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.h
index f9fcfe9878d54..3c9560cb8059b 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.h
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.h
@@ -76,12 +76,14 @@ class RetainTypeChecker {
llvm::DenseSet<const RecordType *> CFPointees;
llvm::DenseSet<const Type *> RecordlessTypes;
bool IsARCEnabled{false};
+ bool DefaultSynthProperties{true};
public:
void visitTranslationUnitDecl(const TranslationUnitDecl *);
void visitTypedef(const TypedefDecl *);
bool isUnretained(const QualType, bool ignoreARC = false);
bool isARCEnabled() const { return IsARCEnabled; }
+ bool defaultSynthProperties() const { return DefaultSynthProperties; }
};
/// \returns true if \p Class is NS or CF objects AND not retained, false if
diff --git
a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefMemberChecker.cpp
b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefMemberChecker.cpp
index b1350b9093021..8faf6a219450a 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefMemberChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefMemberChecker.cpp
@@ -28,6 +28,7 @@ class RawPtrRefMemberChecker
private:
BugType Bug;
mutable BugReporter *BR;
+ mutable llvm::DenseSet<const ObjCIvarDecl *> IvarDeclsToIgnore;
protected:
mutable std::optional<RetainTypeChecker> RTC;
@@ -36,7 +37,8 @@ class RawPtrRefMemberChecker
RawPtrRefMemberChecker(const char *description)
: Bug(this, description, "WebKit coding guidelines") {}
- virtual std::optional<bool> isUnsafePtr(QualType) const = 0;
+ virtual std::optional<bool> isUnsafePtr(QualType,
+ bool ignoreARC = false) const = 0;
virtual const char *typeName() const = 0;
virtual const char *invariant() const = 0;
@@ -138,6 +140,8 @@ class RawPtrRefMemberChecker
return;
}
if (auto *ID = dyn_cast<ObjCImplementationDecl>(CD)) {
+ for (auto *PropImpl : ID->property_impls())
+ visitPropImpl(CD, PropImpl);
for (auto *Ivar : ID->ivars())
visitIvarDecl(CD, Ivar);
return;
@@ -148,6 +152,10 @@ class RawPtrRefMemberChecker
const ObjCIvarDecl *Ivar) const {
if (BR->getSourceManager().isInSystemHeader(Ivar->getLocation()))
return;
+
+ if (IvarDeclsToIgnore.contains(Ivar))
+ return;
+
auto QT = Ivar->getType();
const Type *IvarType = QT.getTypePtrOrNull();
if (!IvarType)
@@ -157,6 +165,8 @@ class RawPtrRefMemberChecker
if (!IsUnsafePtr || !*IsUnsafePtr)
return;
+ IvarDeclsToIgnore.insert(Ivar);
+
if (auto *MemberCXXRD = IvarType->getPointeeCXXRecordDecl())
reportBug(Ivar, IvarType, MemberCXXRD, CD);
else if (auto *ObjCDecl = getObjCDecl(IvarType))
@@ -167,13 +177,15 @@ class RawPtrRefMemberChecker
const ObjCPropertyDecl *PD) const {
if (BR->getSourceManager().isInSystemHeader(PD->getLocation()))
return;
- auto QT = PD->getType();
- const Type *PropType = QT.getTypePtrOrNull();
- if (!PropType)
- return;
- auto IsUnsafePtr = isUnsafePtr(QT);
- if (!IsUnsafePtr || !*IsUnsafePtr)
+ if (const ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CD)) {
+ if (!RTC || !RTC->defaultSynthProperties() ||
+ ID->isObjCRequiresPropertyDefs())
+ return;
+ }
+
+ auto [IsUnsafe, PropType] = isPropImplUnsafePtr(PD);
+ if (!IsUnsafe)
return;
if (auto *MemberCXXRD = PropType->getPointeeCXXRecordDecl())
@@ -182,6 +194,47 @@ class RawPtrRefMemberChecker
reportBug(PD, PropType, ObjCDecl, CD);
}
+ void visitPropImpl(const ObjCContainerDecl *CD,
+ const ObjCPropertyImplDecl *PID) const {
+ if (BR->getSourceManager().isInSystemHeader(PID->getLocation()))
+ return;
+
+ if (PID->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
+ return;
+
+ auto *PropDecl = PID->getPropertyDecl();
+ if (auto *IvarDecl = PID->getPropertyIvarDecl()) {
+ if (IvarDeclsToIgnore.contains(IvarDecl))
+ return;
+ IvarDeclsToIgnore.insert(IvarDecl);
+ }
+ auto [IsUnsafe, PropType] = isPropImplUnsafePtr(PropDecl);
+ if (!IsUnsafe)
+ return;
+
+ if (auto *MemberCXXRD = PropType->getPointeeCXXRecordDecl())
+ reportBug(PropDecl, PropType, MemberCXXRD, CD);
+ else if (auto *ObjCDecl = getObjCDecl(PropType))
+ reportBug(PropDecl, PropType, ObjCDecl, CD);
+ }
+
+ std::pair<bool, const Type *>
+ isPropImplUnsafePtr(const ObjCPropertyDecl *PD) const {
+ if (!PD)
+ return {false, nullptr};
+
+ auto QT = PD->getType();
+ const Type *PropType = QT.getTypePtrOrNull();
+ if (!PropType)
+ return {false, nullptr};
+
+ // "assign" property doesn't retain even under ARC so treat it as unsafe.
+ bool ignoreARC =
+ !PD->isReadOnly() && PD->getSetterKind() == ObjCPropertyDecl::Assign;
+ auto IsUnsafePtr = isUnsafePtr(QT, ignoreARC);
+ return {IsUnsafePtr && *IsUnsafePtr, PropType};
+ }
+
bool shouldSkipDecl(const RecordDecl *RD) const {
if (!RD->isThisDeclarationADefinition())
return true;
@@ -272,7 +325,7 @@ class NoUncountedMemberChecker final : public
RawPtrRefMemberChecker {
: RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to "
"reference-countable type") {}
- std::optional<bool> isUnsafePtr(QualType QT) const final {
+ std::optional<bool> isUnsafePtr(QualType QT, bool) const final {
return isUncountedPtr(QT.getCanonicalType());
}
@@ -289,7 +342,7 @@ class NoUncheckedPtrMemberChecker final : public
RawPtrRefMemberChecker {
: RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to "
"checked-pointer capable type") {}
- std::optional<bool> isUnsafePtr(QualType QT) const final {
+ std::optional<bool> isUnsafePtr(QualType QT, bool) const final {
return isUncheckedPtr(QT.getCanonicalType());
}
@@ -309,8 +362,8 @@ class NoUnretainedMemberChecker final : public
RawPtrRefMemberChecker {
RTC = RetainTypeChecker();
}
- std::optional<bool> isUnsafePtr(QualType QT) const final {
- return RTC->isUnretained(QT);
+ std::optional<bool> isUnsafePtr(QualType QT, bool ignoreARC) const final {
+ return RTC->isUnretained(QT, ignoreARC);
}
const char *typeName() const final { return "retainable type"; }
diff --git a/clang/test/Analysis/Checkers/WebKit/objc-mock-types.h
b/clang/test/Analysis/Checkers/WebKit/objc-mock-types.h
index 93e7dfd77b9e9..9e4356a71f1b5 100644
--- a/clang/test/Analysis/Checkers/WebKit/objc-mock-types.h
+++ b/clang/test/Analysis/Checkers/WebKit/objc-mock-types.h
@@ -22,6 +22,7 @@ typedef struct CF_BRIDGED_TYPE(id) CGImage *CGImageRef;
#define NS_RETURNS_RETAINED __attribute__((ns_returns_retained))
#define CF_CONSUMED __attribute__((cf_consumed))
#define CF_RETURNS_RETAINED __attribute__((cf_returns_retained))
+#define NS_REQUIRES_PROPERTY_DEFINITIONS
__attribute__((objc_requires_property_definitions))
extern const CFAllocatorRef kCFAllocatorDefault;
typedef struct _NSZone NSZone;
diff --git a/clang/test/Analysis/Checkers/WebKit/unretained-members-arc.mm
b/clang/test/Analysis/Checkers/WebKit/unretained-members-arc.mm
index 3491bc93ed98a..00e6e6ec1dcfa 100644
--- a/clang/test/Analysis/Checkers/WebKit/unretained-members-arc.mm
+++ b/clang/test/Analysis/Checkers/WebKit/unretained-members-arc.mm
@@ -64,3 +64,39 @@ void forceTmplToInstantiate(FooTmpl<SomeObj,
CFMutableArrayRef>) {}
};
} // namespace ptr_to_ptr_to_retained
+
+@interface AnotherObject : NSObject {
+ NSString *ns_string;
+ CFStringRef cf_string;
+ // expected-warning@-1{{Instance variable 'cf_string' in 'AnotherObject' is
a retainable type 'CFStringRef'; member variables must be a RetainPtr}}
+}
+@property(nonatomic, strong) NSString *prop_string1;
+@property(nonatomic, assign) NSString *prop_string2;
+// expected-warning@-1{{Property 'prop_string2' in 'AnotherObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@property(nonatomic, unsafe_unretained) NSString *prop_string3;
+// expected-warning@-1{{Property 'prop_string3' in 'AnotherObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@property(nonatomic, readonly) NSString *prop_string4;
+@end
+
+NS_REQUIRES_PROPERTY_DEFINITIONS
+@interface NoSynthObject : NSObject {
+ NSString *ns_string;
+ CFStringRef cf_string;
+ // expected-warning@-1{{Instance variable 'cf_string' in 'NoSynthObject' is
a retainable type 'CFStringRef'; member variables must be a RetainPtr}}
+}
+@property(nonatomic, readonly, strong) NSString *prop_string1;
+@property(nonatomic, readonly, strong) NSString *prop_string2;
+@property(nonatomic, assign) NSString *prop_string3;
+// expected-warning@-1{{Property 'prop_string3' in 'NoSynthObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@property(nonatomic, unsafe_unretained) NSString *prop_string4;
+// expected-warning@-1{{Property 'prop_string4' in 'NoSynthObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@end
+
+@implementation NoSynthObject
+- (NSString *)prop_string1 {
+ return nil;
+}
+@synthesize prop_string2;
+@synthesize prop_string3;
+@synthesize prop_string4;
+@end
diff --git a/clang/test/Analysis/Checkers/WebKit/unretained-members.mm
b/clang/test/Analysis/Checkers/WebKit/unretained-members.mm
index 0cb4c4ac0f6a0..46f65dfa603ad 100644
--- a/clang/test/Analysis/Checkers/WebKit/unretained-members.mm
+++ b/clang/test/Analysis/Checkers/WebKit/unretained-members.mm
@@ -99,3 +99,28 @@ @interface AnotherObject : NSObject {
@property(nonatomic, strong) NSString *prop_string;
// expected-warning@-1{{Property 'prop_string' in 'AnotherObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
@end
+
+NS_REQUIRES_PROPERTY_DEFINITIONS
+@interface NoSynthObject : NSObject {
+ NSString *ns_string;
+ // expected-warning@-1{{Instance variable 'ns_string' in 'NoSynthObject' is
a raw pointer to retainable type 'NSString'; member variables must be a
RetainPtr}}
+ CFStringRef cf_string;
+ // expected-warning@-1{{Instance variable 'cf_string' in 'NoSynthObject' is
a retainable type 'CFStringRef'; member variables must be a RetainPtr}}
+}
+@property(nonatomic, readonly, strong) NSString *prop_string1;
+@property(nonatomic, readonly, strong) NSString *prop_string2;
+// expected-warning@-1{{Property 'prop_string2' in 'NoSynthObject' is a raw
pointer to retainable type 'NSString'}}
+@property(nonatomic, assign) NSString *prop_string3;
+// expected-warning@-1{{Property 'prop_string3' in 'NoSynthObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@property(nonatomic, unsafe_unretained) NSString *prop_string4;
+// expected-warning@-1{{Property 'prop_string4' in 'NoSynthObject' is a raw
pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@end
+
+@implementation NoSynthObject
+- (NSString *)prop_string1 {
+ return nil;
+}
+@synthesize prop_string2;
+@synthesize prop_string3;
+@synthesize prop_string4;
+@end
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