r350942 - [attributes] Extend os_returns_(not_?)_retained attributes to parameters
George Karpenkov via cfe-commits
cfe-commits at lists.llvm.org
Fri Jan 11 10:02:08 PST 2019
Author: george.karpenkov
Date: Fri Jan 11 10:02:08 2019
New Revision: 350942
URL: http://llvm.org/viewvc/llvm-project?rev=350942&view=rev
Log:
[attributes] Extend os_returns_(not_?)_retained attributes to parameters
When applied to out-parameters, the attributes specify the expected lifetime of the written-into object.
Additionally, introduce OSReturnsRetainedOn(Non)Zero attributes, which
specify that an ownership transfer happens depending on a return code.
Differential Revision: https://reviews.llvm.org/D56292
Modified:
cfe/trunk/include/clang/Basic/Attr.td
cfe/trunk/include/clang/Basic/AttrDocs.td
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/SemaDeclAttr.cpp
cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test
cfe/trunk/test/Sema/attr-osobject.cpp
cfe/trunk/test/Sema/attr-osobject.mm
Modified: cfe/trunk/include/clang/Basic/Attr.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/Attr.td (original)
+++ cfe/trunk/include/clang/Basic/Attr.td Fri Jan 11 10:02:08 2019
@@ -841,13 +841,25 @@ def OSConsumed : InheritableParamAttr {
def OSReturnsRetained : InheritableAttr {
let Spellings = [Clang<"os_returns_retained">];
- let Subjects = SubjectList<[Function, ObjCMethod, ObjCProperty]>;
+ let Subjects = SubjectList<[Function, ObjCMethod, ObjCProperty, ParmVar]>;
let Documentation = [RetainBehaviorDocs];
}
def OSReturnsNotRetained : InheritableAttr {
let Spellings = [Clang<"os_returns_not_retained">];
- let Subjects = SubjectList<[Function, ObjCMethod, ObjCProperty]>;
+ let Subjects = SubjectList<[Function, ObjCMethod, ObjCProperty, ParmVar]>;
+ let Documentation = [RetainBehaviorDocs];
+}
+
+def OSReturnsRetainedOnZero : InheritableAttr {
+ let Spellings = [Clang<"os_returns_retained_on_zero">];
+ let Subjects = SubjectList<[ParmVar]>;
+ let Documentation = [RetainBehaviorDocs];
+}
+
+def OSReturnsRetainedOnNonZero : InheritableAttr {
+ let Spellings = [Clang<"os_returns_retained_on_non_zero">];
+ let Subjects = SubjectList<[ParmVar]>;
let Documentation = [RetainBehaviorDocs];
}
Modified: cfe/trunk/include/clang/Basic/AttrDocs.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/AttrDocs.td?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/AttrDocs.td (original)
+++ cfe/trunk/include/clang/Basic/AttrDocs.td Fri Jan 11 10:02:08 2019
@@ -888,6 +888,21 @@ Similar to ``__attribute__((ns_consumes_
``__attribute__((os_consumes_this))`` specifies that the method call consumes
the reference to "this" (e.g., when attaching it to a different object supplied
as a parameter).
+Out parameters (parameters the function is meant to write into,
+either via pointers-to-pointers or references-to-pointers)
+may be annotated with ``__attribute__((os_returns_retained))``
+or ``__attribute__((os_returns_not_retained))`` which specifies that the object
+written into the out parameter should (or respectively should not) be released
+after use.
+Since often out parameters may or may not be written depending on the exit
+code of the function,
+annotations ``__attribute__((os_returns_retained_on_zero))``
+and ``__attribute__((os_returns_retained_on_non_zero))`` specify that
+an out parameter at ``+1`` is written if and only if the function returns a zero
+(respectively non-zero) error code.
+Observe that return-code-dependent out parameter annotations are only
+available for retained out parameters, as non-retained object do not have to be
+released by the callee.
These attributes are only used by the Clang Static Analyzer.
The family of attributes ``X_returns_X_retained`` can be added to functions,
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Fri Jan 11 10:02:08 2019
@@ -3425,7 +3425,7 @@ def err_ns_attribute_wrong_parameter_typ
"%select{Objective-C object|pointer|pointer-to-CF-pointer}1 parameters">;
def warn_ns_attribute_wrong_parameter_type : Warning<
"%0 attribute only applies to "
- "%select{Objective-C object|pointer|pointer-to-CF-pointer}1 parameters">,
+ "%select{Objective-C object|pointer|pointer-to-CF-pointer|pointer/reference-to-OSObject-pointer}1 parameters">,
InGroup<IgnoredAttributes>;
def warn_objc_requires_super_protocol : Warning<
"%0 attribute cannot be applied to %select{methods in protocols|dealloc}1">,
Modified: cfe/trunk/lib/Sema/SemaDeclAttr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclAttr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclAttr.cpp Fri Jan 11 10:02:08 2019
@@ -425,18 +425,17 @@ appendDiagnostics(const Sema::SemaDiagno
std::forward<DiagnosticArgs>(ExtraArgs)...);
}
-/// Add an attribute {@code AttrType} to declaration {@code D},
-/// provided the given {@code Check} function returns {@code true}
-/// on type of {@code D}.
-/// If check does not pass, emit diagnostic {@code DiagID},
-/// passing in all parameters specified in {@code ExtraArgs}.
+/// Add an attribute {@code AttrType} to declaration {@code D}, provided that
+/// {@code PassesCheck} is true.
+/// Otherwise, emit diagnostic {@code DiagID}, passing in all parameters
+/// specified in {@code ExtraArgs}.
template <typename AttrType, typename... DiagnosticArgs>
static void
-handleSimpleAttributeWithCheck(Sema &S, ValueDecl *D, SourceRange SR,
+handleSimpleAttributeOrDiagnose(Sema &S, Decl *D, SourceRange SR,
unsigned SpellingIndex,
- llvm::function_ref<bool(QualType)> Check,
- unsigned DiagID, DiagnosticArgs... ExtraArgs) {
- if (!Check(D->getType())) {
+ bool PassesCheck,
+ unsigned DiagID, DiagnosticArgs&&... ExtraArgs) {
+ if (!PassesCheck) {
Sema::SemaDiagnosticBuilder DB = S.Diag(D->getBeginLoc(), DiagID);
appendDiagnostics(DB, std::forward<DiagnosticArgs>(ExtraArgs)...);
return;
@@ -444,6 +443,17 @@ handleSimpleAttributeWithCheck(Sema &S,
handleSimpleAttribute<AttrType>(S, D, SR, SpellingIndex);
}
+template <typename AttrType, typename... DiagnosticArgs>
+static void
+handleSimpleAttributeOrDiagnose(Sema &S, Decl *D, const ParsedAttr &AL,
+ bool PassesCheck,
+ unsigned DiagID,
+ DiagnosticArgs&&... ExtraArgs) {
+ return handleSimpleAttributeOrDiagnose<AttrType>(
+ S, D, AL.getRange(), AL.getAttributeSpellingListIndex(), PassesCheck,
+ DiagID, std::forward<DiagnosticArgs>(ExtraArgs)...);
+}
+
template <typename AttrType>
static void handleSimpleAttributeWithExclusions(Sema &S, Decl *D,
const ParsedAttr &AL) {
@@ -4781,7 +4791,10 @@ static bool isValidSubjectOfCFAttribute(
}
static bool isValidSubjectOfOSAttribute(QualType QT) {
- return QT->isDependentType() || QT->isPointerType();
+ if (QT->isDependentType())
+ return true;
+ QualType PT = QT->getPointeeType();
+ return !PT.isNull() && PT->getAsCXXRecordDecl() != nullptr;
}
void Sema::AddXConsumedAttr(Decl *D, SourceRange SR, unsigned SpellingIndex,
@@ -4790,14 +4803,14 @@ void Sema::AddXConsumedAttr(Decl *D, Sou
ValueDecl *VD = cast<ValueDecl>(D);
switch (K) {
case RetainOwnershipKind::OS:
- handleSimpleAttributeWithCheck<OSConsumedAttr>(
- *this, VD, SR, SpellingIndex, &isValidSubjectOfOSAttribute,
+ handleSimpleAttributeOrDiagnose<OSConsumedAttr>(
+ *this, VD, SR, SpellingIndex, isValidSubjectOfOSAttribute(VD->getType()),
diag::warn_ns_attribute_wrong_parameter_type,
/*ExtraArgs=*/SR, "os_consumed", /*pointers*/ 1);
return;
case RetainOwnershipKind::NS:
- handleSimpleAttributeWithCheck<NSConsumedAttr>(
- *this, VD, SR, SpellingIndex, &isValidSubjectOfNSAttribute,
+ handleSimpleAttributeOrDiagnose<NSConsumedAttr>(
+ *this, VD, SR, SpellingIndex, isValidSubjectOfNSAttribute(VD->getType()),
// These attributes are normally just advisory, but in ARC, ns_consumed
// is significant. Allow non-dependent code to contain inappropriate
@@ -4809,9 +4822,9 @@ void Sema::AddXConsumedAttr(Decl *D, Sou
/*ExtraArgs=*/SR, "ns_consumed", /*objc pointers*/ 0);
return;
case RetainOwnershipKind::CF:
- handleSimpleAttributeWithCheck<CFConsumedAttr>(
+ handleSimpleAttributeOrDiagnose<CFConsumedAttr>(
*this, VD, SR, SpellingIndex,
- &isValidSubjectOfCFAttribute,
+ isValidSubjectOfCFAttribute(VD->getType()),
diag::warn_ns_attribute_wrong_parameter_type,
/*ExtraArgs=*/SR, "cf_consumed", /*pointers*/1);
return;
@@ -4822,10 +4835,21 @@ static Sema::RetainOwnershipKind
parsedAttrToRetainOwnershipKind(const ParsedAttr &AL) {
switch (AL.getKind()) {
case ParsedAttr::AT_CFConsumed:
+ case ParsedAttr::AT_CFReturnsRetained:
+ case ParsedAttr::AT_CFReturnsNotRetained:
return Sema::RetainOwnershipKind::CF;
+ case ParsedAttr::AT_OSConsumesThis:
case ParsedAttr::AT_OSConsumed:
+ case ParsedAttr::AT_OSReturnsRetained:
+ case ParsedAttr::AT_OSReturnsNotRetained:
+ case ParsedAttr::AT_OSReturnsRetainedOnZero:
+ case ParsedAttr::AT_OSReturnsRetainedOnNonZero:
return Sema::RetainOwnershipKind::OS;
+ case ParsedAttr::AT_NSConsumesSelf:
case ParsedAttr::AT_NSConsumed:
+ case ParsedAttr::AT_NSReturnsRetained:
+ case ParsedAttr::AT_NSReturnsNotRetained:
+ case ParsedAttr::AT_NSReturnsAutoreleased:
return Sema::RetainOwnershipKind::NS;
default:
llvm_unreachable("Wrong argument supplied");
@@ -4841,9 +4865,20 @@ bool Sema::checkNSReturnsRetainedReturnT
return true;
}
+/// \return whether the parameter is a pointer to OSObject pointer.
+static bool isValidOSObjectOutParameter(const Decl *D) {
+ const auto *PVD = dyn_cast<ParmVarDecl>(D);
+ if (!PVD)
+ return false;
+ QualType QT = PVD->getType();
+ QualType PT = QT->getPointeeType();
+ return !PT.isNull() && isValidSubjectOfOSAttribute(PT);
+}
+
static void handleXReturnsXRetainedAttr(Sema &S, Decl *D,
const ParsedAttr &AL) {
QualType ReturnType;
+ Sema::RetainOwnershipKind K = parsedAttrToRetainOwnershipKind(AL);
if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
ReturnType = MD->getReturnType();
@@ -4857,10 +4892,13 @@ static void handleXReturnsXRetainedAttr(
} else if (const auto *Param = dyn_cast<ParmVarDecl>(D)) {
// Attributes on parameters are used for out-parameters,
// passed as pointers-to-pointers.
+ unsigned DiagID = K == Sema::RetainOwnershipKind::CF
+ ? /*pointer-to-CF-pointer*/2
+ : /*pointer-to-OSObject-pointer*/3;
ReturnType = Param->getType()->getPointeeType();
if (ReturnType.isNull()) {
S.Diag(D->getBeginLoc(), diag::warn_ns_attribute_wrong_parameter_type)
- << AL << /*pointer-to-CF-pointer*/ 2 << AL.getRange();
+ << AL << DiagID << AL.getRange();
return;
}
} else if (AL.isUsedAsTypeAttr()) {
@@ -4872,11 +4910,11 @@ static void handleXReturnsXRetainedAttr(
case ParsedAttr::AT_NSReturnsRetained:
case ParsedAttr::AT_NSReturnsAutoreleased:
case ParsedAttr::AT_NSReturnsNotRetained:
- case ParsedAttr::AT_OSReturnsRetained:
- case ParsedAttr::AT_OSReturnsNotRetained:
ExpectedDeclKind = ExpectedFunctionOrMethod;
break;
+ case ParsedAttr::AT_OSReturnsRetained:
+ case ParsedAttr::AT_OSReturnsNotRetained:
case ParsedAttr::AT_CFReturnsRetained:
case ParsedAttr::AT_CFReturnsNotRetained:
ExpectedDeclKind = ExpectedFunctionMethodOrParameter;
@@ -4889,6 +4927,7 @@ static void handleXReturnsXRetainedAttr(
bool TypeOK;
bool Cf;
+ unsigned ParmDiagID = 2; // Pointer-to-CF-pointer
switch (AL.getKind()) {
default: llvm_unreachable("invalid ownership attribute");
case ParsedAttr::AT_NSReturnsRetained:
@@ -4912,6 +4951,7 @@ static void handleXReturnsXRetainedAttr(
case ParsedAttr::AT_OSReturnsNotRetained:
TypeOK = isValidSubjectOfOSAttribute(ReturnType);
Cf = true;
+ ParmDiagID = 3; // Pointer-to-OSObject-pointer
break;
}
@@ -4921,7 +4961,7 @@ static void handleXReturnsXRetainedAttr(
if (isa<ParmVarDecl>(D)) {
S.Diag(D->getBeginLoc(), diag::warn_ns_attribute_wrong_parameter_type)
- << AL << /*pointer-to-CF*/ 2 << AL.getRange();
+ << AL << ParmDiagID << AL.getRange();
} else {
// Needs to be kept in sync with warn_ns_attribute_wrong_return_type.
enum : unsigned {
@@ -6513,6 +6553,18 @@ static void ProcessDeclAttribute(Sema &S
case ParsedAttr::AT_OSConsumesThis:
handleSimpleAttribute<OSConsumesThisAttr>(S, D, AL);
break;
+ case ParsedAttr::AT_OSReturnsRetainedOnZero:
+ handleSimpleAttributeOrDiagnose<OSReturnsRetainedOnZeroAttr>(
+ S, D, AL, isValidOSObjectOutParameter(D),
+ diag::warn_ns_attribute_wrong_parameter_type,
+ /*Extra Args=*/AL, /*pointer-to-OSObject-pointer*/ 3, AL.getRange());
+ break;
+ case ParsedAttr::AT_OSReturnsRetainedOnNonZero:
+ handleSimpleAttributeOrDiagnose<OSReturnsRetainedOnNonZeroAttr>(
+ S, D, AL, isValidOSObjectOutParameter(D),
+ diag::warn_ns_attribute_wrong_parameter_type,
+ /*Extra Args=*/AL, /*pointer-to-OSObject-poointer*/ 3, AL.getRange());
+ break;
case ParsedAttr::AT_NSReturnsAutoreleased:
case ParsedAttr::AT_NSReturnsNotRetained:
case ParsedAttr::AT_NSReturnsRetained:
Modified: cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test (original)
+++ cfe/trunk/test/Misc/pragma-attribute-supported-attributes-list.test Fri Jan 11 10:02:08 2019
@@ -86,8 +86,10 @@
// CHECK-NEXT: NoThrow (SubjectMatchRule_function)
// CHECK-NEXT: NotTailCalled (SubjectMatchRule_function)
// CHECK-NEXT: OSConsumed (SubjectMatchRule_variable_is_parameter)
-// CHECK-NEXT: OSReturnsNotRetained (SubjectMatchRule_function, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property)
-// CHECK-NEXT: OSReturnsRetained (SubjectMatchRule_function, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property)
+// CHECK-NEXT: OSReturnsNotRetained (SubjectMatchRule_function, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property, SubjectMatchRule_variable_is_parameter)
+// CHECK-NEXT: OSReturnsRetained (SubjectMatchRule_function, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property, SubjectMatchRule_variable_is_parameter)
+// CHECK-NEXT: OSReturnsRetainedOnNonZero (SubjectMatchRule_variable_is_parameter)
+// CHECK-NEXT: OSReturnsRetainedOnZero (SubjectMatchRule_variable_is_parameter)
// CHECK-NEXT: ObjCBoxable (SubjectMatchRule_record)
// CHECK-NEXT: ObjCBridge (SubjectMatchRule_record, SubjectMatchRule_type_alias)
// CHECK-NEXT: ObjCBridgeMutable (SubjectMatchRule_record)
Modified: cfe/trunk/test/Sema/attr-osobject.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-osobject.cpp?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/test/Sema/attr-osobject.cpp (original)
+++ cfe/trunk/test/Sema/attr-osobject.cpp Fri Jan 11 10:02:08 2019
@@ -37,12 +37,38 @@ __attribute__((os_returns_retained(10)))
return nullptr;
}
-struct __attribute__((os_returns_retained)) NoRetainAttrOnStruct {}; // expected-warning{{'os_returns_retained' attribute only applies to functions, Objective-C methods, and Objective-C properties}}
+struct __attribute__((os_returns_retained)) NoRetainAttrOnStruct {}; // expected-warning{{'os_returns_retained' attribute only applies to functions, Objective-C methods, Objective-C properties, and parameters}}
__attribute__((os_returns_not_retained(10))) S* os_returns_no_retained_no_extra_args( S *arg) { // expected-error{{'os_returns_not_retained' attribute takes no arguments}}
return nullptr;
}
-struct __attribute__((os_returns_not_retained)) NoNotRetainedAttrOnStruct {}; // expected-warning{{'os_returns_not_retained' attribute only applies to functions, Objective-C methods, and Objective-C properties}}
+struct __attribute__((os_returns_not_retained)) NoNotRetainedAttrOnStruct {}; // expected-warning{{'os_returns_not_retained' attribute only applies to functions, Objective-C methods, Objective-C properties, and parameters}}
__attribute__((os_consumes_this)) void no_consumes_this_on_function() {} // expected-warning{{'os_consumes_this' attribute only applies to non-static member functions}}
+
+void write_into_out_parameter(__attribute__((os_returns_retained)) S** out) {}
+
+bool write_into_out_parameter_on_nonzero(__attribute__((os_returns_retained_on_non_zero)) S** out) {}
+
+bool write_into_out_parameter_on_nonzero_invalid(__attribute__((os_returns_retained_on_non_zero)) S* out) {} // expected-warning{{'os_returns_retained_on_non_zero' attribute only applies to pointer/reference-to-OSObject-pointer parameters}}
+
+bool write_into_out_parameter_on_zero(__attribute__((os_returns_retained_on_zero)) S** out) {}
+
+bool write_into_out_parameter_on_zero_invalid(__attribute__((os_returns_retained_on_zero)) S* out) {} // expected-warning{{'os_returns_retained_on_zero' attribute only applies to pointer/reference-to-OSObject-pointer parameters}}
+
+void write_into_out_parameter_ref(__attribute__((os_returns_retained)) S*& out) {}
+
+typedef S* SPtr;
+
+void write_into_out_parameter_typedef(__attribute__((os_returns_retained)) SPtr* out) {}
+
+void write_into_out_parameter_invalid(__attribute__((os_returns_retained)) S* out) {} // expected-warning{{'os_returns_retained' attribute only applies to pointer/reference-to-OSObject-pointer parameters}}
+
+void write_into_out_parameter_not_retained(__attribute__((os_returns_not_retained)) S **out) {}
+
+void write_into_out_parameter_not_retained(__attribute__((os_returns_not_retained)) S volatile * const * const out) {}
+
+void write_into_not_retainedout_parameter_invalid(__attribute__((os_returns_not_retained)) S* out) {} // expected-warning{{'os_returns_not_retained' attribute only applies to pointer/reference-to-OSObject-pointer parameters}}
+
+void write_into_not_retainedout_parameter_too_many_pointers(__attribute__((os_returns_not_retained)) S*** out) {} // expected-warning{{'os_returns_not_retained' attribute only applies to pointer/reference-to-OSObject-pointer parameters}}
Modified: cfe/trunk/test/Sema/attr-osobject.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-osobject.mm?rev=350942&r1=350941&r2=350942&view=diff
==============================================================================
--- cfe/trunk/test/Sema/attr-osobject.mm (original)
+++ cfe/trunk/test/Sema/attr-osobject.mm Fri Jan 11 10:02:08 2019
@@ -8,8 +8,8 @@ struct S {};
- (void) takeS:(S*) __attribute__((os_consumed)) s;
@end
-typedef __attribute__((os_returns_retained)) id (^blockType)(); // expected-warning{{'os_returns_retained' attribute only applies to functions, Objective-C methods, and Objective-C properties}}
+typedef __attribute__((os_returns_retained)) id (^blockType)(); // expected-warning{{'os_returns_retained' attribute only applies to functions, Objective-C methods, Objective-C properties, and parameters}}
-__auto_type b = ^ id (id filter) __attribute__((os_returns_retained)) { // expected-warning{{'os_returns_retained' attribute only applies to functions, Objective-C methods, and Objective-C properties}}
+__auto_type b = ^ id (id filter) __attribute__((os_returns_retained)) { // expected-warning{{'os_returns_retained' attribute only applies to functions, Objective-C methods, Objective-C properties, and parameters}}
return filter;
};
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