Exposed a declarative way to specify that an attribute can be duplicated when merging attributes on a declaration. This replaces some hard-coded functionality from Sema.
llvm-svn: 199677
diff --git a/clang/docs/InternalsManual.rst b/clang/docs/InternalsManual.rst
index 40a1a09..eb19614 100644
--- a/clang/docs/InternalsManual.rst
+++ b/clang/docs/InternalsManual.rst
@@ -1713,6 +1713,11 @@
kind, but ARMInterruptAttr and MSP430InterruptAttr are the semantic attributes
generated.
+By default, when declarations are merging attributes, an attribute will not be
+duplicated. However, if an attribute can be duplicated during this merging
+stage, set ``DuplicatesAllowedWhileMerging`` to ``1``, and the attribute will
+be merged.
+
If additional functionality is desired for the semantic form of the attribute,
the ``AdditionalMembers`` field specifies code to be copied verbatim into the
semantic attribute class object.
diff --git a/clang/include/clang/AST/Attr.h b/clang/include/clang/AST/Attr.h
index 01c32c0..822686a 100644
--- a/clang/include/clang/AST/Attr.h
+++ b/clang/include/clang/AST/Attr.h
@@ -108,6 +108,11 @@
// Pretty print this attribute.
virtual void printPretty(raw_ostream &OS,
const PrintingPolicy &Policy) const = 0;
+
+ /// \brief By default, attributes cannot be duplicated when being merged;
+ /// however, an attribute can override this. Returns true if the attribute
+ /// can be duplicated when merging.
+ virtual bool duplicatesAllowed() const { return false; }
};
class InheritableAttr : public Attr {
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 28b8ade..82b991a 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -210,6 +210,9 @@
// Set to true if all of the attribute's arguments should be parsed in an
// unevaluated context.
bit ParseArgumentsAsUnevaluated = 0;
+ // Set to true if this attribute can be duplicated on a subject when merging
+ // attributes. By default, attributes are not merged.
+ bit DuplicatesAllowedWhileMerging = 0;
// Lists language options, one of which is required to be true for the
// attribute to be applicable. If empty, no language options are required.
list<LangOpt> LangOpts = [];
@@ -340,6 +343,7 @@
.Default(llvm::StringRef());
} }];
let HasCustomParsing = 1;
+ let DuplicatesAllowedWhileMerging = 1;
// let Subjects = SubjectList<[Named]>;
}
@@ -1112,6 +1116,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[Field, SharedVar], WarnDiag,
"ExpectedFieldOrGlobalVar">;
}
@@ -1122,6 +1127,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[Field, SharedVar], WarnDiag,
"ExpectedFieldOrGlobalVar">;
}
@@ -1132,6 +1138,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[Field, SharedVar], WarnDiag,
"ExpectedFieldOrGlobalVar">;
}
@@ -1142,6 +1149,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[Field, SharedVar], WarnDiag,
"ExpectedFieldOrGlobalVar">;
}
@@ -1152,6 +1160,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1161,6 +1170,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1190,6 +1200,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1201,6 +1212,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1210,6 +1222,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1228,6 +1241,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1237,6 +1251,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
@@ -1246,6 +1261,7 @@
let LateParsed = 1;
let TemplateDependent = 1;
let ParseArgumentsAsUnevaluated = 1;
+ let DuplicatesAllowedWhileMerging = 1;
let Subjects = SubjectList<[FunctionDefinition, FunctionTemplate]>;
}
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index f71540c..6d46903 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1795,34 +1795,7 @@
/// DeclhasAttr - returns true if decl Declaration already has the target
/// attribute.
-static bool
-DeclHasAttr(const Decl *D, const Attr *A) {
- // There can be multiple AvailabilityAttr in a Decl. Make sure we copy
- // all of them. It is mergeAvailabilityAttr in SemaDeclAttr.cpp that is
- // responsible for making sure they are consistent.
- const AvailabilityAttr *AA = dyn_cast<AvailabilityAttr>(A);
- if (AA)
- return false;
-
- // The following thread safety attributes can also be duplicated.
- switch (A->getKind()) {
- case attr::ExclusiveLocksRequired:
- case attr::SharedLocksRequired:
- case attr::LocksExcluded:
- case attr::ExclusiveLockFunction:
- case attr::SharedLockFunction:
- case attr::UnlockFunction:
- case attr::ExclusiveTrylockFunction:
- case attr::SharedTrylockFunction:
- case attr::GuardedBy:
- case attr::PtGuardedBy:
- case attr::AcquiredBefore:
- case attr::AcquiredAfter:
- return false;
- default:
- ;
- }
-
+static bool DeclHasAttr(const Decl *D, const Attr *A) {
const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(A);
const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(A);
for (Decl::attr_iterator i = D->attr_begin(), e = D->attr_end(); i != e; ++i)
@@ -1997,7 +1970,7 @@
// AlignedAttrs are handled separately, because we need to handle all
// such attributes on a declaration at the same time.
NewAttr = 0;
- else if (!DeclHasAttr(D, Attr))
+ else if (Attr->duplicatesAllowed() || !DeclHasAttr(D, Attr))
NewAttr = cast<InheritableAttr>(Attr->clone(S.Context));
if (NewAttr) {
diff --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp
index c1916cb..7caba49 100644
--- a/clang/utils/TableGen/ClangAttrEmitter.cpp
+++ b/clang/utils/TableGen/ClangAttrEmitter.cpp
@@ -1353,6 +1353,9 @@
OS << " virtual bool isLateParsed() const { return "
<< LateParsed << "; }\n";
+ if (R.getValueAsBit("DuplicatesAllowedWhileMerging"))
+ OS << " virtual bool duplicatesAllowed() const { return true; }\n\n";
+
OS << "};\n\n";
}