diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h index d1c77f5e080c..623d9c4792e7 100644 --- a/clang/include/clang/AST/Decl.h +++ b/clang/include/clang/AST/Decl.h @@ -3235,6 +3235,18 @@ public: return isCompleteDefinition() || isFixed(); } + /// Returns true if this enum is either annotated with + /// enum_extensibility(closed) or isn't annotated with enum_extensibility. + bool isClosed() const; + + /// Returns true if this enum is annotated with flag_enum and isn't annotated + /// with enum_extensibility(open). + bool isClosedFlag() const; + + /// Returns true if this enum is annotated with neither flag_enum nor + /// enum_extensibility(open). + bool isClosedNonFlag() const; + /// \brief Retrieve the enum definition from which this enumeration could /// be instantiated, if it is an instantiation (rather than a non-template). EnumDecl *getTemplateInstantiationPattern() const; diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td index 5960cca1e795..ff62e10f8adb 100644 --- a/clang/include/clang/Basic/Attr.td +++ b/clang/include/clang/Basic/Attr.td @@ -881,7 +881,15 @@ def FlagEnum : InheritableAttr { let Spellings = [GNU<"flag_enum">]; let Subjects = SubjectList<[Enum]>; let Documentation = [FlagEnumDocs]; - let LangOpts = [COnly]; +} + +def EnumExtensibility : InheritableAttr { + let Spellings = [GNU<"enum_extensibility">, + CXX11<"clang", "enum_extensibility">]; + let Subjects = SubjectList<[Enum]>; + let Args = [EnumArgument<"Extensibility", "Kind", + ["closed", "open"], ["Closed", "Open"]>]; + let Documentation = [EnumExtensibilityDocs]; } def Flatten : InheritableAttr { diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td index df299e07c673..23b9bb7188e7 100644 --- a/clang/include/clang/Basic/AttrDocs.td +++ b/clang/include/clang/Basic/AttrDocs.td @@ -1963,6 +1963,55 @@ manipulating bits of the enumerator when issuing warnings. }]; } +def EnumExtensibilityDocs : Documentation { + let Category = DocCatType; + let Content = [{ +Attribute ``enum_extensibility`` is used to distinguish between enum definitions +that are extensible and those that are not. The attribute can take either +``closed`` or ``open`` as an argument. ``closed`` indicates a variable of the +enum type takes a value that corresponds to one of the enumerators listed in the +enum definition or, when the enum is annotated with ``flag_enum``, a value that +can be constructed using values corresponding to the enumerators. ``open`` +indicates a variable of the enum type can take any values allowed by the +standard and instructs clang to be more lenient when issuing warnings. + +.. code-block:: c + + enum __attribute__((enum_extensibility(closed))) ClosedEnum { + A0, A1 + }; + + enum __attribute__((enum_extensibility(open))) OpenEnum { + B0, B1 + }; + + enum __attribute__((enum_extensibility(closed),flag_enum)) ClosedFlagEnum { + C0 = 1 << 0, C1 = 1 << 1 + }; + + enum __attribute__((enum_extensibility(open),flag_enum)) OpenFlagEnum { + D0 = 1 << 0, D1 = 1 << 1 + }; + + void foo1() { + enum ClosedEnum ce; + enum OpenEnum oe; + enum ClosedFlagEnum cfe; + enum OpenFlagEnum ofe; + + ce = A1; // no warnings + ce = 100; // warning issued + oe = B1; // no warnings + oe = 100; // no warnings + cfe = C0 | C1; // no warnings + cfe = C0 | C1 | 4; // warning issued + ofe = D0 | D1; // no warnings + ofe = D0 | D1 | 4; // no warnings + } + + }]; +} + def EmptyBasesDocs : Documentation { let Category = DocCatType; let Content = [{ diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp index cc6f2fa70541..5b0404e38dde 100644 --- a/clang/lib/AST/Decl.cpp +++ b/clang/lib/AST/Decl.cpp @@ -3742,6 +3742,20 @@ void EnumDecl::completeDefinition(QualType NewType, TagDecl::completeDefinition(); } +bool EnumDecl::isClosed() const { + if (const auto *A = getAttr()) + return A->getExtensibility() == EnumExtensibilityAttr::Closed; + return true; +} + +bool EnumDecl::isClosedFlag() const { + return isClosed() && hasAttr(); +} + +bool EnumDecl::isClosedNonFlag() const { + return isClosed() && !hasAttr(); +} + TemplateSpecializationKind EnumDecl::getTemplateSpecializationKind() const { if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo()) return MSI->getTemplateSpecializationKind(); diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index d7d71221b5de..bc5f60504df2 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -15358,7 +15358,7 @@ static void CheckForDuplicateEnumValues(Sema &S, ArrayRef Elements, bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val, bool AllowMask) const { - assert(ED->hasAttr() && "looking for value in non-flag enum"); + assert(ED->isClosedFlag() && "looking for value in non-flag or open enum"); assert(ED->isCompleteDefinition() && "expected enum definition"); auto R = FlagBitsCache.insert(std::make_pair(ED, llvm::APInt())); @@ -15603,7 +15603,7 @@ void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange, CheckForDuplicateEnumValues(*this, Elements, Enum, EnumType); - if (Enum->hasAttr()) { + if (Enum->isClosedFlag()) { for (Decl *D : Elements) { EnumConstantDecl *ECD = cast_or_null(D); if (!ECD) continue; // Already issued a diagnostic. diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index 3979383966c8..1c350a7e38b7 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -2943,6 +2943,28 @@ static void handleCleanupAttr(Sema &S, Decl *D, const AttributeList &Attr) { Attr.getAttributeSpellingListIndex())); } +static void handleEnumExtensibilityAttr(Sema &S, Decl *D, + const AttributeList &Attr) { + if (!Attr.isArgIdent(0)) { + S.Diag(Attr.getLoc(), diag::err_attribute_argument_n_type) + << Attr.getName() << 0 << AANT_ArgumentIdentifier; + return; + } + + EnumExtensibilityAttr::Kind ExtensibilityKind; + IdentifierInfo *II = Attr.getArgAsIdent(0)->Ident; + if (!EnumExtensibilityAttr::ConvertStrToKind(II->getName(), + ExtensibilityKind)) { + S.Diag(Attr.getLoc(), diag::warn_attribute_type_not_supported) + << Attr.getName() << II; + return; + } + + D->addAttr(::new (S.Context) EnumExtensibilityAttr( + Attr.getRange(), S.Context, ExtensibilityKind, + Attr.getAttributeSpellingListIndex())); +} + /// Handle __attribute__((format_arg((idx)))) attribute based on /// http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html static void handleFormatArgAttr(Sema &S, Decl *D, const AttributeList &Attr) { @@ -5856,6 +5878,9 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D, case AttributeList::AT_FlagEnum: handleSimpleAttribute(S, D, Attr); break; + case AttributeList::AT_EnumExtensibility: + handleEnumExtensibilityAttr(S, D, Attr); + break; case AttributeList::AT_Flatten: handleSimpleAttribute(S, D, Attr); break; diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp index 3f6c46795514..f393e3e7941c 100644 --- a/clang/lib/Sema/SemaStmt.cpp +++ b/clang/lib/Sema/SemaStmt.cpp @@ -711,6 +711,9 @@ static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S, EnumValsTy::iterator &EI, EnumValsTy::iterator &EIEnd, const llvm::APSInt &Val) { + if (!ED->isClosed()) + return false; + if (const DeclRefExpr *DRE = dyn_cast(CaseExpr->IgnoreParenImpCasts())) { if (const VarDecl *VD = dyn_cast(DRE->getDecl())) { @@ -722,15 +725,14 @@ static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S, } } - if (ED->hasAttr()) { + if (ED->hasAttr()) return !S.IsValueInFlagEnum(ED, Val, false); - } else { - while (EI != EIEnd && EI->first < Val) - EI++; - if (EI != EIEnd && EI->first == Val) - return false; - } + while (EI != EIEnd && EI->first < Val) + EI++; + + if (EI != EIEnd && EI->first == Val) + return false; return true; } @@ -1147,7 +1149,7 @@ Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, } } - if (TheDefaultStmt && UnhandledNames.empty()) + if (TheDefaultStmt && UnhandledNames.empty() && ED->isClosedNonFlag()) Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); // Produce a nice diagnostic if multiple values aren't handled. @@ -1198,6 +1200,9 @@ Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType, AdjustAPSInt(RhsVal, DstWidth, DstIsSigned); const EnumDecl *ED = ET->getDecl(); + if (!ED->isClosed()) + return; + if (ED->hasAttr()) { if (!IsValueInFlagEnum(ED, RhsVal, true)) Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment) diff --git a/clang/test/Sema/enum-attr.c b/clang/test/Sema/enum-attr.c new file mode 100644 index 000000000000..933d8ccdcd89 --- /dev/null +++ b/clang/test/Sema/enum-attr.c @@ -0,0 +1,130 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -Wassign-enum -Wswitch-enum -Wcovered-switch-default %s + +enum Enum { + A0 = 1, A1 = 10 +}; + +enum __attribute__((enum_extensibility(closed))) EnumClosed { + B0 = 1, B1 = 10 +}; + +enum __attribute__((enum_extensibility(open))) EnumOpen { + C0 = 1, C1 = 10 +}; + +enum __attribute__((flag_enum)) EnumFlag { + D0 = 1, D1 = 8 +}; + +enum __attribute__((flag_enum,enum_extensibility(closed))) EnumFlagClosed { + E0 = 1, E1 = 8 +}; + +enum __attribute__((flag_enum,enum_extensibility(open))) EnumFlagOpen { + F0 = 1, F1 = 8 +}; + +enum __attribute__((enum_extensibility(arg1))) EnumInvalidArg { // expected-warning{{'enum_extensibility' attribute argument not supported: 'arg1'}} + X0 +}; + +// FIXME: The warning should mention that enum_extensibility takes only one argument. +enum __attribute__((enum_extensibility(closed,open))) EnumTooManyArgs { // expected-error{{use of undeclared identifier 'open'}} + X1 +}; + +enum __attribute__((enum_extensibility())) EnumTooFewArgs { // expected-error{{'enum_extensibility' attribute takes one argument}} + X2 +}; + +struct __attribute__((enum_extensibility(open))) S { // expected-warning{{'enum_extensibility' attribute only applies to enums}}{ +}; + +void test() { + enum Enum t0 = 100; // expected-warning{{integer constant not in range of enumerated type}} + t0 = 1; + + switch (t0) { // expected-warning{{enumeration value 'A1' not handled in switch}} + case A0: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t0) { + case A0: break; + case A1: break; + default: break; // expected-warning{{default label in switch which covers all enumeration}} + } + + enum EnumClosed t1 = 100; // expected-warning{{integer constant not in range of enumerated type}} + t1 = 1; + + switch (t1) { // expected-warning{{enumeration value 'B1' not handled in switch}} + case B0: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t1) { + case B0: break; + case B1: break; + default: break; // expected-warning{{default label in switch which covers all enumeration}} + } + + enum EnumOpen t2 = 100; + t2 = 1; + + switch (t2) { // expected-warning{{enumeration value 'C1' not handled in switch}} + case C0: break; + case 16: break; + } + + switch (t2) { + case C0: break; + case C1: break; + default: break; + } + + enum EnumFlag t3 = 5; // expected-warning{{integer constant not in range of enumerated type}} + t3 = 9; + + switch (t3) { // expected-warning{{enumeration value 'D1' not handled in switch}} + case D0: break; + case 9: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t3) { + case D0: break; + case D1: break; + default: break; + } + + enum EnumFlagClosed t4 = 5; // expected-warning{{integer constant not in range of enumerated type}} + t4 = 9; + + switch (t4) { // expected-warning{{enumeration value 'E1' not handled in switch}} + case E0: break; + case 9: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t4) { + case E0: break; + case E1: break; + default: break; + } + + enum EnumFlagOpen t5 = 5; + t5 = 9; + + switch (t5) { // expected-warning{{enumeration value 'F1' not handled in switch}} + case F0: break; + case 9: break; + case 16: break; + } + + switch (t5) { + case F0: break; + case F1: break; + default: break; + } +} diff --git a/clang/test/SemaCXX/attr-flag-enum-reject.cpp b/clang/test/SemaCXX/attr-flag-enum-reject.cpp deleted file mode 100644 index f28d60c0c295..000000000000 --- a/clang/test/SemaCXX/attr-flag-enum-reject.cpp +++ /dev/null @@ -1,4 +0,0 @@ -// RUN: %clang_cc1 -verify -fsyntax-only -x c++ -Wassign-enum %s - -enum __attribute__((flag_enum)) flag { // expected-warning {{ignored}} -}; diff --git a/clang/test/SemaCXX/enum-attr.cpp b/clang/test/SemaCXX/enum-attr.cpp new file mode 100644 index 000000000000..7726aff4830a --- /dev/null +++ b/clang/test/SemaCXX/enum-attr.cpp @@ -0,0 +1,108 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -Wassign-enum -Wswitch-enum -Wcovered-switch-default -std=c++11 %s + +enum Enum { + A0 = 1, A1 = 10 +}; + +enum __attribute__((enum_extensibility(closed))) EnumClosed { + B0 = 1, B1 = 10 +}; + +enum [[clang::enum_extensibility(open)]] EnumOpen { + C0 = 1, C1 = 10 +}; + +enum __attribute__((flag_enum)) EnumFlag { + D0 = 1, D1 = 8 +}; + +enum __attribute__((flag_enum,enum_extensibility(closed))) EnumFlagClosed { + E0 = 1, E1 = 8 +}; + +enum __attribute__((flag_enum,enum_extensibility(open))) EnumFlagOpen { + F0 = 1, F1 = 8 +}; + +void test() { + enum Enum t0; + + switch (t0) { // expected-warning{{enumeration value 'A1' not handled in switch}} + case A0: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t0) { + case A0: break; + case A1: break; + default: break; // expected-warning{{default label in switch which covers all enumeration}} + } + + enum EnumClosed t1; + + switch (t1) { // expected-warning{{enumeration value 'B1' not handled in switch}} + case B0: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t1) { + case B0: break; + case B1: break; + default: break; // expected-warning{{default label in switch which covers all enumeration}} + } + + enum EnumOpen t2; + + switch (t2) { // expected-warning{{enumeration value 'C1' not handled in switch}} + case C0: break; + case 16: break; + } + + switch (t2) { + case C0: break; + case C1: break; + default: break; + } + + enum EnumFlag t3; + + switch (t3) { // expected-warning{{enumeration value 'D1' not handled in switch}} + case D0: break; + case 9: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t3) { + case D0: break; + case D1: break; + default: break; + } + + enum EnumFlagClosed t4; + + switch (t4) { // expected-warning{{enumeration value 'E1' not handled in switch}} + case E0: break; + case 9: break; + case 16: break; // expected-warning{{case value not in enumerated type}} + } + + switch (t4) { + case E0: break; + case E1: break; + default: break; + } + + enum EnumFlagOpen t5; + + switch (t5) { // expected-warning{{enumeration value 'F1' not handled in switch}} + case F0: break; + case 9: break; + case 16: break; + } + + switch (t5) { + case F0: break; + case F1: break; + default: break; + } +}