Implement C++11 semantics for [[noreturn]] attribute. This required splitting
it apart from [[gnu::noreturn]] / __attribute__((noreturn)), since their
semantics are not equivalent (for instance, we treat [[gnu::noreturn]] as
affecting the function type, whereas [[noreturn]] does not).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172691 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 103ac1b..c053b6d 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1808,6 +1808,11 @@
return true;
}
+bool FunctionDecl::isNoReturn() const {
+ return hasAttr<NoReturnAttr>() || hasAttr<CXX11NoReturnAttr>() ||
+ getType()->getAs<FunctionType>()->getNoReturnAttr();
+}
+
void
FunctionDecl::setPreviousDeclaration(FunctionDecl *PrevDecl) {
redeclarable_base::setPreviousDeclaration(PrevDecl);
diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 043066b..cd0ff0a 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -807,7 +807,7 @@
Ty = Context->getBaseElementType(Ty);
const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor();
- if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr())
+ if (Dtor->isNoReturn())
Block = createNoReturnBlock();
else
autoCreateBlock();
@@ -1402,7 +1402,7 @@
}
if (FunctionDecl *FD = C->getDirectCallee()) {
- if (FD->hasAttr<NoReturnAttr>())
+ if (FD->isNoReturn())
NoReturn = true;
if (FD->hasAttr<NoThrowAttr>())
AddEHEdge = false;
@@ -3190,7 +3190,7 @@
// a new block for the destructor which does not have as a successor
// anything built thus far. Control won't flow out of this block.
const CXXDestructorDecl *Dtor = E->getTemporary()->getDestructor();
- if (cast<FunctionType>(Dtor->getType())->getNoReturnAttr())
+ if (Dtor->isNoReturn())
Block = createNoReturnBlock();
else
autoCreateBlock();
@@ -3327,10 +3327,8 @@
}
bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const {
- if (const CXXDestructorDecl *decl = getDestructorDecl(astContext)) {
- QualType ty = decl->getType();
- return cast<FunctionType>(ty)->getNoReturnAttr();
- }
+ if (const CXXDestructorDecl *DD = getDestructorDecl(astContext))
+ return DD->isNoReturn();
return false;
}
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 878b73d..d9a0045 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -989,7 +989,8 @@
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
}
- if (TargetDecl->hasAttr<NoReturnAttr>())
+ if (TargetDecl->hasAttr<NoReturnAttr>() ||
+ TargetDecl->hasAttr<CXX11NoReturnAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
if (TargetDecl->hasAttr<ReturnsTwiceAttr>())
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 1fbe6b3..74769bf 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -902,6 +902,8 @@
ConsumeAnyToken();
if (OnDefinition && !IsThreadSafetyAttribute(LA.AttrName.getName())) {
+ // FIXME: Do not warn on C++11 attributes, once we start supporting
+ // them here.
Diag(Tok, diag::warn_attribute_on_function_definition)
<< LA.AttrName.getName();
}
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 7fe49fd..d78cc51 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -3032,7 +3032,7 @@
AttributeList::AS_CXX11)) {
case AttributeList::AT_CarriesDependency:
case AttributeList::AT_FallThrough:
- case AttributeList::AT_NoReturn: {
+ case AttributeList::AT_CXX11NoReturn: {
return true;
}
@@ -3095,6 +3095,8 @@
ConsumeBracket();
ConsumeBracket();
+ llvm::SmallDenseMap<IdentifierInfo*, SourceLocation, 4> SeenAttrs;
+
while (Tok.isNot(tok::r_square)) {
// attribute not present
if (Tok.is(tok::comma)) {
@@ -3128,6 +3130,11 @@
bool StandardAttr = IsBuiltInOrStandardCXX11Attribute(AttrName,ScopeName);
bool AttrParsed = false;
+ if (StandardAttr &&
+ !SeenAttrs.insert(std::make_pair(AttrName, AttrLoc)).second)
+ Diag(AttrLoc, diag::err_cxx11_attribute_repeated)
+ << AttrName << SourceRange(SeenAttrs[AttrName]);
+
// Parse attribute arguments
if (Tok.is(tok::l_paren)) {
if (ScopeName && ScopeName->getName() == "gnu") {
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 759ab7f..20e515d 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -944,7 +944,8 @@
if (Tok.isNot(tok::equal)) {
AttributeList *DtorAttrs = D.getAttributes();
while (DtorAttrs) {
- if (!IsThreadSafetyAttribute(DtorAttrs->getName()->getName())) {
+ if (!IsThreadSafetyAttribute(DtorAttrs->getName()->getName()) &&
+ !DtorAttrs->isCXX11Attribute()) {
Diag(DtorAttrs->getLoc(), diag::warn_attribute_on_function_definition)
<< DtorAttrs->getName()->getName();
}
diff --git a/lib/Sema/AnalysisBasedWarnings.cpp b/lib/Sema/AnalysisBasedWarnings.cpp
index ba23467..d5fa959 100644
--- a/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/lib/Sema/AnalysisBasedWarnings.cpp
@@ -329,8 +329,7 @@
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
ReturnsVoid = FD->getResultType()->isVoidType();
- HasNoReturn = FD->hasAttr<NoReturnAttr>() ||
- FD->getType()->getAs<FunctionType>()->getNoReturnAttr();
+ HasNoReturn = FD->isNoReturn();
}
else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
ReturnsVoid = MD->getResultType()->isVoidType();
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 5ddc26a..728a58e 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2276,6 +2276,18 @@
}
}
+ // C++11 [dcl.attr.noreturn]p1:
+ // The first declaration of a function shall specify the noreturn
+ // attribute if any declaration of that function specifies the noreturn
+ // attribute.
+ if (New->hasAttr<CXX11NoReturnAttr>() &&
+ !Old->hasAttr<CXX11NoReturnAttr>()) {
+ Diag(New->getAttr<CXX11NoReturnAttr>()->getLocation(),
+ diag::err_noreturn_missing_on_first_decl);
+ Diag(Old->getFirstDeclaration()->getLocation(),
+ diag::note_noreturn_missing_first_decl);
+ }
+
// (C++98 8.3.5p3):
// All declarations for a function shall agree exactly in both the
// return type and the parameter-type-list.
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index acd075e..45220f6 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -1684,6 +1684,21 @@
D->addAttr(::new (S.Context) AnalyzerNoReturnAttr(Attr.getRange(), S.Context));
}
+static void handleCXX11NoReturnAttr(Sema &S, Decl *D,
+ const AttributeList &Attr) {
+ // C++11 [dcl.attr.noreturn]p1:
+ // The attribute may be applied to the declarator-id in a function
+ // declaration.
+ FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
+ if (!FD) {
+ S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
+ << Attr.getName() << ExpectedFunctionOrMethod;
+ return;
+ }
+
+ D->addAttr(::new (S.Context) CXX11NoReturnAttr(Attr.getRange(), S.Context));
+}
+
// PS3 PPU-specific.
static void handleVecReturnAttr(Sema &S, Decl *D, const AttributeList &Attr) {
/*
@@ -4272,10 +4287,10 @@
static void ProcessInheritableDeclAttr(Sema &S, Scope *scope, Decl *D,
const AttributeList &Attr) {
switch (Attr.getKind()) {
- case AttributeList::AT_IBAction: handleIBAction(S, D, Attr); break;
- case AttributeList::AT_IBOutlet: handleIBOutlet(S, D, Attr); break;
- case AttributeList::AT_IBOutletCollection:
- handleIBOutletCollection(S, D, Attr); break;
+ case AttributeList::AT_IBAction: handleIBAction(S, D, Attr); break;
+ case AttributeList::AT_IBOutlet: handleIBOutlet(S, D, Attr); break;
+ case AttributeList::AT_IBOutletCollection:
+ handleIBOutletCollection(S, D, Attr); break;
case AttributeList::AT_AddressSpace:
case AttributeList::AT_OpenCLImageAccess:
case AttributeList::AT_ObjCGC:
@@ -4306,6 +4321,9 @@
case AttributeList::AT_Common: handleCommonAttr (S, D, Attr); break;
case AttributeList::AT_CUDAConstant:handleConstantAttr (S, D, Attr); break;
case AttributeList::AT_Constructor: handleConstructorAttr (S, D, Attr); break;
+ case AttributeList::AT_CXX11NoReturn:
+ handleCXX11NoReturnAttr(S, D, Attr);
+ break;
case AttributeList::AT_Deprecated:
handleAttrWithMessage<DeprecatedAttr>(S, D, Attr, "deprecated");
break;
@@ -4542,11 +4560,11 @@
/// ProcessDeclAttribute - Apply the specific attribute to the specified decl if
/// the attribute applies to decls. If the attribute is a type attribute, just
-/// silently ignore it if a GNU attribute. FIXME: Applying a C++0x attribute to
-/// the wrong thing is illegal (C++0x [dcl.attr.grammar]/4).
+/// silently ignore it if a GNU attribute.
static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
const AttributeList &Attr,
- bool NonInheritable, bool Inheritable) {
+ bool NonInheritable, bool Inheritable,
+ bool IncludeCXX11Attributes) {
if (Attr.isInvalid())
return;
@@ -4557,6 +4575,11 @@
if (Attr.isMSTypespecAttribute())
return;
+ // Ignore C++11 attributes on declarator chunks: they appertain to the type
+ // instead.
+ if (Attr.isCXX11Attribute() && !IncludeCXX11Attributes)
+ return;
+
if (NonInheritable)
ProcessNonInheritableDeclAttr(S, scope, D, Attr);
@@ -4568,10 +4591,11 @@
/// attribute list to the specified decl, ignoring any type attributes.
void Sema::ProcessDeclAttributeList(Scope *S, Decl *D,
const AttributeList *AttrList,
- bool NonInheritable, bool Inheritable) {
- for (const AttributeList* l = AttrList; l; l = l->getNext()) {
- ProcessDeclAttribute(*this, S, D, *l, NonInheritable, Inheritable);
- }
+ bool NonInheritable, bool Inheritable,
+ bool IncludeCXX11Attributes) {
+ for (const AttributeList* l = AttrList; l; l = l->getNext())
+ ProcessDeclAttribute(*this, S, D, *l, NonInheritable, Inheritable,
+ IncludeCXX11Attributes);
// GCC accepts
// static int a9 __attribute__((weakref));
@@ -4736,7 +4760,8 @@
// when X is a decl attribute.
for (unsigned i = 0, e = PD.getNumTypeObjects(); i != e; ++i)
if (const AttributeList *Attrs = PD.getTypeObject(i).getAttrs())
- ProcessDeclAttributeList(S, D, Attrs, NonInheritable, Inheritable);
+ ProcessDeclAttributeList(S, D, Attrs, NonInheritable, Inheritable,
+ /*IncludeCXX11Attributes=*/false);
// Finally, apply any attributes on the decl itself.
if (const AttributeList *Attrs = PD.getAttributes())
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 09c4180..db314fa 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2419,8 +2419,7 @@
QualType RelatedRetType;
if (const FunctionDecl *FD = getCurFunctionDecl()) {
FnRetType = FD->getResultType();
- if (FD->hasAttr<NoReturnAttr>() ||
- FD->getType()->getAs<FunctionType>()->getNoReturnAttr())
+ if (FD->isNoReturn())
Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
<< FD->getDeclName();
} else if (ObjCMethodDecl *MD = getCurMethodDecl()) {
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index e849e05..7029543 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -4189,24 +4189,43 @@
if (attr.isInvalid())
continue;
- // [[gnu::...]] attributes are treated as declaration attributes, so may
- // not appertain to a DeclaratorChunk, even if we handle them as type
- // attributes.
- // FIXME: All other C++11 type attributes may *only* appertain to a type,
- // and should only be considered here if they appertain to a
- // DeclaratorChunk.
- if (attr.isCXX11Attribute() && TAL == TAL_DeclChunk &&
- attr.getScopeName() && attr.getScopeName()->isStr("gnu")) {
- state.getSema().Diag(attr.getLoc(),
- diag::warn_cxx11_gnu_attribute_on_type)
- << attr.getName();
- continue;
+ if (attr.isCXX11Attribute()) {
+ // [[gnu::...]] attributes are treated as declaration attributes, so may
+ // not appertain to a DeclaratorChunk, even if we handle them as type
+ // attributes.
+ if (attr.getScopeName() && attr.getScopeName()->isStr("gnu")) {
+ if (TAL == TAL_DeclChunk) {
+ state.getSema().Diag(attr.getLoc(),
+ diag::warn_cxx11_gnu_attribute_on_type)
+ << attr.getName();
+ continue;
+ }
+ } else if (TAL != TAL_DeclChunk) {
+ // Otherwise, only consider type processing for a C++11 attribute if
+ // it's actually been applied to a type.
+ continue;
+ }
}
// If this is an attribute we can handle, do so now,
// otherwise, add it to the FnAttrs list for rechaining.
switch (attr.getKind()) {
- default: break;
+ default:
+ // A C++11 attribute on a declarator chunk must appertain to a type.
+ if (attr.isCXX11Attribute() && TAL == TAL_DeclChunk)
+ state.getSema().Diag(attr.getLoc(), diag::err_attribute_not_type_attr)
+ << attr.getName()->getName();
+ break;
+
+ case AttributeList::UnknownAttribute:
+ if (attr.isCXX11Attribute() && TAL == TAL_DeclChunk)
+ state.getSema().Diag(attr.getLoc(),
+ diag::warn_unknown_attribute_ignored)
+ << attr.getName();
+ break;
+
+ case AttributeList::IgnoredAttribute:
+ break;
case AttributeList::AT_MayAlias:
// FIXME: This attribute needs to actually be handled, but if we ignore
@@ -4255,7 +4274,7 @@
case AttributeList::AT_NSReturnsRetained:
if (!state.getSema().getLangOpts().ObjCAutoRefCount)
- break;
+ break;
// fallthrough into the function attrs
FUNCTION_TYPE_ATTRS_CASELIST:
diff --git a/lib/StaticAnalyzer/Checkers/NoReturnFunctionChecker.cpp b/lib/StaticAnalyzer/Checkers/NoReturnFunctionChecker.cpp
index 2439147..37d9113 100644
--- a/lib/StaticAnalyzer/Checkers/NoReturnFunctionChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/NoReturnFunctionChecker.cpp
@@ -48,7 +48,7 @@
if (!FD)
return;
- if (FD->getAttr<AnalyzerNoReturnAttr>())
+ if (FD->getAttr<AnalyzerNoReturnAttr>() || FD->isNoReturn())
BuildSinks = true;
else if (const IdentifierInfo *II = FD->getIdentifier()) {
// HACK: Some functions are not marked noreturn, and don't return.