Start adding support for dllimport/dllexport on classes (PR11170)
This implements the central part of support for dllimport/dllexport on
classes: allowing the attribute on class declarations, inheriting it
to class members, and forcing emission of exported members. It's based
on Nico Rieck's patch from http://reviews.llvm.org/D1099.
This patch doesn't propagate dllexport to bases that are template
specializations, which is an interesting problem. It also doesn't
look at the rules when redeclaring classes with different attributes,
I'd like to do that separately.
Differential Revision: http://reviews.llvm.org/D3877
llvm-svn: 209908
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index da93b04..48c2c5d 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -4350,6 +4350,8 @@
/// \brief Return a DLL attribute from the declaration.
static InheritableAttr *getDLLAttr(Decl *D) {
+ assert(!(D->hasAttr<DLLImportAttr>() && D->hasAttr<DLLExportAttr>()) &&
+ "A declaration cannot be both dllimport and dllexport.");
if (auto *Import = D->getAttr<DLLImportAttr>())
return Import;
if (auto *Export = D->getAttr<DLLExportAttr>())
@@ -4357,6 +4359,59 @@
return nullptr;
}
+/// \brief Check class-level dllimport/dllexport attribute.
+static void checkDLLAttribute(Sema &S, CXXRecordDecl *Class) {
+ Attr *ClassAttr = getDLLAttr(Class);
+ if (!ClassAttr)
+ return;
+
+ bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
+
+ // Force declaration of implicit members so they can inherit the attribute.
+ S.ForceDeclarationOfImplicitMembers(Class);
+
+ // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
+ // seem to be true in practice?
+
+ // FIXME: We also need to propagate the attribute upwards to class template
+ // specialization bases.
+
+ for (Decl *Member : Class->decls()) {
+ if (getDLLAttr(Member)) {
+ // FIXME: Error about importing/exporting individual members.
+ }
+
+ if (!isa<CXXMethodDecl>(Member) && !isa<VarDecl>(Member))
+ continue;
+
+ auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(S.getASTContext()));
+ NewAttr->setInherited(true);
+ Member->addAttr(NewAttr);
+
+ if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member)) {
+ if (ClassExported) {
+ if (MD->isDeleted())
+ continue;
+
+ if (MD->isUserProvided()) {
+ // Instantiate non-default methods.
+ S.MarkFunctionReferenced(Class->getLocation(), MD);
+ } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
+ MD->isCopyAssignmentOperator() ||
+ MD->isMoveAssignmentOperator()) {
+ // Instantiate non-trival or explicitly defaulted methods, and the
+ // copy assignment / move assignment operators.
+ S.MarkFunctionReferenced(Class->getLocation(), MD);
+ // Resolve its exception specification; CodeGen needs it.
+ auto *FPT = MD->getType()->getAs<FunctionProtoType>();
+ S.ResolveExceptionSpec(Class->getLocation(), FPT);
+ S.ActOnFinishInlineMethodDef(MD);
+ }
+ }
+ }
+ }
+}
+
/// \brief Perform semantic checks on a class definition that has been
/// completing, introducing implicitly-declared members, checking for
/// abstract types, etc.
@@ -4521,6 +4576,8 @@
// instantiated (e.g. meta-functions). This doesn't apply to classes that
// have inheriting constructors.
DeclareInheritingConstructors(Record);
+
+ checkDLLAttribute(*this, Record);
}
/// Look up the special member function that would be called by a special