QualType mergeObjCGCQualifiers(QualType, QualType);
- bool doFunctionTypesMatchOnExtParameterInfos(
- const FunctionProtoType *FromFunctionType,
- const FunctionProtoType *ToFunctionType);
+ /// This function merges the ExtParameterInfo lists of two functions. It
+ /// returns true if the lists are compatible. The merged list is returned in
+ /// NewParamInfos.
+ ///
+ /// \param FirstFnType The type of the first function.
+ ///
+ /// \param SecondFnType The type of the second function.
+ ///
+ /// \param CanUseFirst This flag is set to true if the first function's
+ /// ExtParameterInfo list can be used as the composite list of
+ /// ExtParameterInfo.
+ ///
+ /// \param CanUseSecond This flag is set to true if the second function's
+ /// ExtParameterInfo list can be used as the composite list of
+ /// ExtParameterInfo.
+ ///
+ /// \param NewParamInfos The composite list of ExtParameterInfo. The list is
+ /// empty if none of the flags are set.
+ ///
+ bool mergeExtParameterInfo(
+ const FunctionProtoType *FirstFnType,
+ const FunctionProtoType *SecondFnType,
+ bool &CanUseFirst, bool &CanUseSecond,
+ SmallVectorImpl<FunctionProtoType::ExtParameterInfo> &NewParamInfos);
void ResetObjCLayout(const ObjCContainerDecl *CD);
ABIMask = 0x0F,
IsConsumed = 0x10,
HasPassObjSize = 0x20,
+ IsNoEscape = 0x40,
};
unsigned char Data;
return Copy;
}
+ bool isNoEscape() const {
+ return Data & IsNoEscape;
+ }
+
+ ExtParameterInfo withIsNoEscape(bool NoEscape) const {
+ ExtParameterInfo Copy = *this;
+ if (NoEscape)
+ Copy.Data |= IsNoEscape;
+ else
+ Copy.Data &= ~IsNoEscape;
+ return Copy;
+ }
+
unsigned char getOpaqueValue() const { return Data; }
static ExtParameterInfo getFromOpaqueValue(unsigned char data) {
ExtParameterInfo result;
let Documentation = [Undocumented];
}
+def NoEscape : Attr {
+ let Spellings = [GNU<"noescape">, CXX11<"clang", "noescape">];
+ let Subjects = SubjectList<[ParmVar]>;
+ let Documentation = [NoEscapeDocs];
+}
+
def AssumeAligned : InheritableAttr {
let Spellings = [GCC<"assume_aligned">];
let Subjects = SubjectList<[ObjCMethod, Function]>;
}];
}
+def NoEscapeDocs : Documentation {
+ let Category = DocCatVariable;
+ let Content = [{
+``noescape`` placed on a function parameter of a pointer type is used to inform
+the compiler that the pointer cannot escape: that is, no reference to the object
+the pointer points to that is derived from the parameter value will survive
+after the function returns. Users are responsible for making sure parameters
+annotated with ``noescape`` do not actuallly escape.
+
+For example:
+
+.. code-block:: c
+ int *gp;
+
+ void nonescapingFunc(__attribute__((noescape)) int *p) {
+ *p += 100; // OK.
+ }
+
+ void escapingFunc(__attribute__((noescape)) int *p) {
+ gp = p; // Not OK.
+ }
+
+Additionally, when the parameter is a `block pointer
+<https://clang.llvm.org/docs/BlockLanguageSpec.html>`, the same restriction
+applies to copies of the block. For example:
+
+ typedef void (^BlockTy)();
+ BlockTy g0, g1;
+
+ void nonescapingFunc(__attribute__((noescape)) BlockTy block) {
+ block(); // OK.
+ }
+
+ void escapingFunc(__attribute__((noescape)) BlockTy block) {
+ g0 = block; // Not OK.
+ g1 = Block_copy(block); // Not OK either.
+ }
+
+ }];
+}
+
def CarriesDependencyDocs : Documentation {
let Category = DocCatFunction;
let Content = [{
DiagGroup<"gnu-string-literal-operator-template">;
def UndefinedVarTemplate : DiagGroup<"undefined-var-template">;
def UndefinedFuncTemplate : DiagGroup<"undefined-func-template">;
+def MissingNoEscape : DiagGroup<"missing-noescape">;
def DeleteIncomplete : DiagGroup<"delete-incomplete">;
def DeleteNonVirtualDtor : DiagGroup<"delete-non-virtual-dtor">;
"virtual function %0 has different calling convention attributes "
"%diff{($) than the function it overrides (which has calling convention $)|"
"than the function it overrides}1,2">;
+def warn_overriding_method_missing_noescape : Warning<
+ "parameter of overriding method should be annotated with "
+ "__attribute__((noescape))">, InGroup<MissingNoEscape>;
+def note_overridden_marked_noescape : Note<
+ "parameter of overridden method is annotated with __attribute__((noescape))">;
def err_covariant_return_inaccessible_base : Error<
"invalid covariant return for virtual function: %1 is a "
if (lproto->getTypeQuals() != rproto->getTypeQuals())
return QualType();
- if (!doFunctionTypesMatchOnExtParameterInfos(rproto, lproto))
+ SmallVector<FunctionProtoType::ExtParameterInfo, 4> newParamInfos;
+ bool canUseLeft, canUseRight;
+ if (!mergeExtParameterInfo(lproto, rproto, canUseLeft, canUseRight,
+ newParamInfos))
return QualType();
+ if (!canUseLeft)
+ allLTypes = false;
+ if (!canUseRight)
+ allRTypes = false;
+
// Check parameter type compatibility
SmallVector<QualType, 10> types;
for (unsigned i = 0, n = lproto->getNumParams(); i < n; i++) {
FunctionProtoType::ExtProtoInfo EPI = lproto->getExtProtoInfo();
EPI.ExtInfo = einfo;
+ EPI.ExtParameterInfos =
+ newParamInfos.empty() ? nullptr : newParamInfos.data();
return getFunctionType(retType, types, EPI);
}
llvm_unreachable("Invalid Type::Class!");
}
-bool ASTContext::doFunctionTypesMatchOnExtParameterInfos(
- const FunctionProtoType *firstFnType,
- const FunctionProtoType *secondFnType) {
+bool ASTContext::mergeExtParameterInfo(
+ const FunctionProtoType *FirstFnType, const FunctionProtoType *SecondFnType,
+ bool &CanUseFirst, bool &CanUseSecond,
+ SmallVectorImpl<FunctionProtoType::ExtParameterInfo> &NewParamInfos) {
+ assert(NewParamInfos.empty() && "param info list not empty");
+ CanUseFirst = CanUseSecond = true;
+ bool FirstHasInfo = FirstFnType->hasExtParameterInfos();
+ bool SecondHasInfo = SecondFnType->hasExtParameterInfos();
+
// Fast path: if the first type doesn't have ext parameter infos,
- // we match if and only if they second type also doesn't have them.
- if (!firstFnType->hasExtParameterInfos())
- return !secondFnType->hasExtParameterInfos();
+ // we match if and only if the second type also doesn't have them.
+ if (!FirstHasInfo && !SecondHasInfo)
+ return true;
- // Otherwise, we can only match if the second type has them.
- if (!secondFnType->hasExtParameterInfos())
- return false;
+ bool NeedParamInfo = false;
+ size_t E = FirstHasInfo ? FirstFnType->getExtParameterInfos().size()
+ : SecondFnType->getExtParameterInfos().size();
- auto firstEPI = firstFnType->getExtParameterInfos();
- auto secondEPI = secondFnType->getExtParameterInfos();
- assert(firstEPI.size() == secondEPI.size());
+ for (size_t I = 0; I < E; ++I) {
+ FunctionProtoType::ExtParameterInfo FirstParam, SecondParam;
+ if (FirstHasInfo)
+ FirstParam = FirstFnType->getExtParameterInfo(I);
+ if (SecondHasInfo)
+ SecondParam = SecondFnType->getExtParameterInfo(I);
- for (size_t i = 0, n = firstEPI.size(); i != n; ++i) {
- if (firstEPI[i] != secondEPI[i])
+ // Cannot merge unless everything except the noescape flag matches.
+ if (FirstParam.withIsNoEscape(false) != SecondParam.withIsNoEscape(false))
return false;
+
+ bool FirstNoEscape = FirstParam.isNoEscape();
+ bool SecondNoEscape = SecondParam.isNoEscape();
+ bool IsNoEscape = FirstNoEscape && SecondNoEscape;
+ NewParamInfos.push_back(FirstParam.withIsNoEscape(IsNoEscape));
+ if (NewParamInfos.back().getOpaqueValue())
+ NeedParamInfo = true;
+ if (FirstNoEscape != IsNoEscape)
+ CanUseFirst = false;
+ if (SecondNoEscape != IsNoEscape)
+ CanUseSecond = false;
}
+
+ if (!NeedParamInfo)
+ NewParamInfos.clear();
+
return true;
}
if (PI.isConsumed())
mangleVendorQualifier("ns_consumed");
+
+ if (PI.isNoEscape())
+ mangleVendorQualifier("noescape");
}
// <type> ::= <function-type>
auto EPI = T->getExtParameterInfo(i);
if (EPI.isConsumed()) OS << "__attribute__((ns_consumed)) ";
+ if (EPI.isNoEscape())
+ OS << "__attribute__((noescape)) ";
auto ABI = EPI.getABI();
if (ABI != ParameterABI::Ordinary)
OS << "__attribute__((" << getParameterABISpelling(ABI) << ")) ";
CodeGenTypes::arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD,
QualType receiverType) {
SmallVector<CanQualType, 16> argTys;
+ SmallVector<FunctionProtoType::ExtParameterInfo, 4> extParamInfos(2);
argTys.push_back(Context.getCanonicalParamType(receiverType));
argTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType()));
// FIXME: Kill copy?
for (const auto *I : MD->parameters()) {
argTys.push_back(Context.getCanonicalParamType(I->getType()));
+ auto extParamInfo = FunctionProtoType::ExtParameterInfo().withIsNoEscape(
+ I->hasAttr<NoEscapeAttr>());
+ extParamInfos.push_back(extParamInfo);
}
FunctionType::ExtInfo einfo;
return arrangeLLVMFunctionInfo(
GetReturnType(MD->getReturnType()), /*instanceMethod=*/false,
- /*chainCall=*/false, argTys, einfo, {}, required);
+ /*chainCall=*/false, argTys, einfo, extParamInfos, required);
}
const CGFunctionInfo &
break;
}
+ if (FI.getExtParameterInfo(ArgNo).isNoEscape())
+ Attrs.addAttribute(llvm::Attribute::NoCapture);
+
if (Attrs.hasAttributes()) {
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
Attr.getAttributeSpellingListIndex()));
}
+static void handleNoEscapeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
+ if (D->isInvalidDecl())
+ return;
+
+ // noescape only applies to pointer types.
+ QualType T = cast<ParmVarDecl>(D)->getType();
+ if (!S.isValidPointerAttrType(T, /* RefOkay */ true)) {
+ S.Diag(Attr.getLoc(), diag::warn_attribute_pointers_only)
+ << Attr.getName() << Attr.getRange() << 0;
+ return;
+ }
+
+ D->addAttr(::new (S.Context) NoEscapeAttr(
+ Attr.getRange(), S.Context, Attr.getAttributeSpellingListIndex()));
+}
+
static void handleAssumeAlignedAttr(Sema &S, Decl *D,
const AttributeList &Attr) {
Expr *E = Attr.getArgAsExpr(0),
case AttributeList::AT_ReturnsNonNull:
handleReturnsNonNullAttr(S, D, Attr);
break;
+ case AttributeList::AT_NoEscape:
+ handleNoEscapeAttr(S, D, Attr);
+ break;
case AttributeList::AT_AssumeAligned:
handleAssumeAlignedAttr(S, D, Attr);
break;
bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
const CXXMethodDecl *Old) {
- const FunctionType *NewFT = New->getType()->getAs<FunctionType>();
- const FunctionType *OldFT = Old->getType()->getAs<FunctionType>();
+ const auto *NewFT = New->getType()->getAs<FunctionProtoType>();
+ const auto *OldFT = Old->getType()->getAs<FunctionProtoType>();
+
+ if (OldFT->hasExtParameterInfos()) {
+ for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
+ // A parameter of the overriding method should be annotated with noescape
+ // if the corresponding parameter of the overridden method is annotated.
+ if (OldFT->getExtParameterInfo(I).isNoEscape() &&
+ !NewFT->getExtParameterInfo(I).isNoEscape()) {
+ Diag(New->getParamDecl(I)->getLocation(),
+ diag::warn_overriding_method_missing_noescape);
+ Diag(Old->getParamDecl(I)->getLocation(),
+ diag::note_overridden_marked_noescape);
+ }
+ }
CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
Diag(newDecl->getLocation(), diag::warn_nsconsumed_attribute_mismatch);
Diag(oldDecl->getLocation(), diag::note_previous_decl) << "parameter";
}
+
+ // A parameter of the overriding method should be annotated with noescape
+ // if the corresponding parameter of the overridden method is annotated.
+ if (oldDecl->hasAttr<NoEscapeAttr>() && !newDecl->hasAttr<NoEscapeAttr>()) {
+ Diag(newDecl->getLocation(),
+ diag::warn_overriding_method_missing_noescape);
+ Diag(oldDecl->getLocation(), diag::note_overridden_marked_noescape);
+ }
}
}
.getTypePtr());
Changed = true;
}
+
+ // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
+ // only if the ExtParameterInfo lists of the two function prototypes can be
+ // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
+ SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
+ bool CanUseToFPT, CanUseFromFPT;
+ if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
+ CanUseFromFPT, NewParamInfos) &&
+ CanUseToFPT && !CanUseFromFPT) {
+ FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
+ ExtInfo.ExtParameterInfos =
+ NewParamInfos.empty() ? nullptr : NewParamInfos.data();
+ QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
+ FromFPT->getParamTypes(), ExtInfo);
+ FromFn = QT->getAs<FunctionType>();
+ Changed = true;
+ }
}
if (!Changed)
// Argument types are too different. Abort.
return false;
}
- if (!Context.doFunctionTypesMatchOnExtParameterInfos(FromFunctionType,
- ToFunctionType))
+
+ SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
+ bool CanUseToFPT, CanUseFromFPT;
+ if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
+ CanUseToFPT, CanUseFromFPT,
+ NewParamInfos))
return false;
ConvertedType = ToType;
HasAnyInterestingExtParameterInfos = true;
}
+ if (Param->hasAttr<NoEscapeAttr>()) {
+ ExtParameterInfos[i] = ExtParameterInfos[i].withIsNoEscape(true);
+ HasAnyInterestingExtParameterInfos = true;
+ }
+
ParamTys.push_back(ParamTy);
}
// CHECK: FunctionDecl{{.*}} TestExternalSourceSymbolAttr5
// CHECK-NEXT: ExternalSourceSymbolAttr{{.*}} "Swift" "module" GeneratedDeclaration
+namespace TestNoEscape {
+ void noescapeFunc(int *p0, __attribute__((noescape)) int *p1) {}
+ // CHECK: `-FunctionDecl{{.*}} noescapeFunc 'void (int *, __attribute__((noescape)) int *)'
+ // CHECK-NEXT: ParmVarDecl
+ // CHECK-NEXT: ParmVarDecl
+ // CHECK-NEXT: NoEscapeAttr
+}
+
namespace TestSuppress {
[[gsl::suppress("at-namespace")]];
// CHECK: NamespaceDecl{{.*}} TestSuppress
// The number of supported attributes should never go down!
-// CHECK: #pragma clang attribute supports 64 attributes:
+// CHECK: #pragma clang attribute supports 65 attributes:
// CHECK-NEXT: AMDGPUFlatWorkGroupSize (SubjectMatchRule_function)
// CHECK-NEXT: AMDGPUNumSGPR (SubjectMatchRule_function)
// CHECK-NEXT: AMDGPUNumVGPR (SubjectMatchRule_function)
// CHECK-NEXT: MipsShortCall (SubjectMatchRule_function)
// CHECK-NEXT: NoDebug (SubjectMatchRule_hasType_functionType, SubjectMatchRule_objc_method, SubjectMatchRule_variable_not_is_parameter)
// CHECK-NEXT: NoDuplicate (SubjectMatchRule_function)
+// CHECK-NEXT: NoEscape (SubjectMatchRule_variable_is_parameter)
// CHECK-NEXT: NoMicroMips (SubjectMatchRule_function)
// CHECK-NEXT: NoSanitize (SubjectMatchRule_function, SubjectMatchRule_objc_method, SubjectMatchRule_variable_is_global)
// CHECK-NEXT: NoSanitizeSpecific (SubjectMatchRule_function, SubjectMatchRule_variable_is_global)