Wire up basic parser/sema support for attribute 'returns_nonnull'.
This attribute is supported by GCC. More generally it should
probably be a type attribute, but this behavior matches 'nonnull'.
This patch does not include warning logic for checking if a null
value is returned from a function annotated with this attribute.
That will come in subsequent patches.
llvm-svn: 199626
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index cb739fb..5869692 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -693,6 +693,12 @@
} }];
}
+def ReturnsNonNull : InheritableAttr {
+ let Spellings = [GNU<"returns_nonnull">];
+ let Subjects = SubjectList<[ObjCMethod, FunctionLike, HasFunctionProto],
+ WarnDiag, "ExpectedFunctionOrMethod">;
+}
+
def NoReturn : InheritableAttr {
let Spellings = [GNU<"noreturn">, CXX11<"gnu", "noreturn">,
Declspec<"noreturn">];
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 59ade9e..ac5b406 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1847,6 +1847,9 @@
"%0 attribute only applies to pointer arguments">,
InGroup<IgnoredAttributes>;
def err_attribute_pointers_only : Error<warn_attribute_pointers_only.Text>;
+def warn_attribute_return_pointers_only : Warning<
+ "%0 attribute only applies to return values that are pointers">,
+ InGroup<IgnoredAttributes>;
def err_attribute_no_member_pointers : Error<
"%0 attribute cannot be used with pointers to members">;
def err_attribute_invalid_implicit_this_argument : Error<
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index eaad404..ed8610c 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -1157,12 +1157,14 @@
}
static bool attrNonNullArgCheck(Sema &S, QualType T, const AttributeList &Attr,
- SourceRange R) {
+ SourceRange R, bool isReturnValue = false) {
T = T.getNonReferenceType();
possibleTransparentUnionPointerType(T);
if (!T->isAnyPointerType() && !T->isBlockPointerType()) {
- S.Diag(Attr.getLoc(), diag::warn_attribute_pointers_only)
+ S.Diag(Attr.getLoc(),
+ isReturnValue ? diag::warn_attribute_return_pointers_only
+ : diag::warn_attribute_pointers_only)
<< Attr.getName() << R;
return false;
}
@@ -1231,6 +1233,23 @@
Attr.getAttributeSpellingListIndex()));
}
+static void handleReturnsNonNullAttr(Sema &S, Decl *D,
+ const AttributeList &Attr) {
+ QualType ResultType;
+ if (const FunctionType *Ty = D->getFunctionType())
+ ResultType = Ty->getResultType();
+ else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
+ ResultType = MD->getResultType();
+
+ if (!attrNonNullArgCheck(S, ResultType, Attr, Attr.getRange(),
+ /* isReturnValue */ true))
+ return;
+
+ D->addAttr(::new (S.Context)
+ ReturnsNonNullAttr(Attr.getRange(), S.Context,
+ Attr.getAttributeSpellingListIndex()));
+}
+
static const char *ownershipKindToDiagName(OwnershipAttr::OwnershipKind K) {
switch (K) {
case OwnershipAttr::Holds: return "'ownership_holds'";
@@ -3978,6 +3997,9 @@
else
handleNonNullAttr(S, D, Attr);
break;
+ case AttributeList::AT_ReturnsNonNull:
+ handleReturnsNonNullAttr(S, D, Attr);
+ break;
case AttributeList::AT_Overloadable:
handleSimpleAttribute<OverloadableAttr>(S, D, Attr); break;
case AttributeList::AT_Ownership: handleOwnershipAttr (S, D, Attr); break;
diff --git a/clang/test/Sema/nonnull.c b/clang/test/Sema/nonnull.c
index 3c56075..f1ba482 100644
--- a/clang/test/Sema/nonnull.c
+++ b/clang/test/Sema/nonnull.c
@@ -32,4 +32,10 @@
baz3(0); // no-warning
}
+void test_void_returns_nonnull() __attribute__((returns_nonnull)); // expected-warning {{'returns_nonnull' attribute only applies to return values that are pointers}}
+int test_int_returns_nonnull() __attribute__((returns_nonnull)); // expected-warning {{'returns_nonnull' attribute only applies to return values that are pointers}}
+void *test_ptr_returns_nonnull() __attribute__((returns_nonnull)); // no-warning
+
int i __attribute__((nonnull)); // expected-warning {{'nonnull' attribute only applies to functions, methods, and parameters}}
+int j __attribute__((returns_nonnull)); // expected-warning {{'returns_nonnull' attribute only applies to functions and methods}}
+
diff --git a/clang/test/SemaObjC/nonnull.m b/clang/test/SemaObjC/nonnull.m
index d9ecbdc..f6e4f57 100644
--- a/clang/test/SemaObjC/nonnull.m
+++ b/clang/test/SemaObjC/nonnull.m
@@ -74,6 +74,9 @@
@interface NSObject
- (void)doSomethingWithNonNullPointer:(void *)ptr :(int)iarg : (void*)ptr1 __attribute__((nonnull(1, 3)));
+ (void)doSomethingClassyWithNonNullPointer:(void *)ptr __attribute__((nonnull(1)));
+- (void*)returnsCNonNull __attribute__((returns_nonnull)); // no-warning
+- (id)returnsObjCNonNull __attribute__((returns_nonnull)); // no-warning
+- (int)returnsIntNonNull __attribute__((returns_nonnull)); // expected-warning {{'returns_nonnull' attribute only applies to return values that are pointers}}
@end
extern void DoSomethingNotNull(void *db) __attribute__((nonnull(1)));