[ObjC] Implement @available in the Parser and AST
This patch adds a new AST node: ObjCAvailabilityCheckExpr, and teaches the
Parser and Sema to generate it. This node represents an availability check of
the form:
@available(macos 10.10, *);
Which will eventually compile to a runtime check of the host's OS version. This
is the first patch of the feature I proposed here:
http://lists.llvm.org/pipermail/cfe-dev/2016-July/049851.html
Differential Revision: https://reviews.llvm.org/D22171
llvm-svn: 275654
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 4e39d42..47d1326 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -1009,6 +1009,8 @@
case tok::kw__Generic: // primary-expression: generic-selection [C11 6.5.1]
Res = ParseGenericSelectionExpression();
break;
+ case tok::kw___builtin_available:
+ return ParseAvailabilityCheckExpr(Tok.getLocation());
case tok::kw___builtin_va_arg:
case tok::kw___builtin_offsetof:
case tok::kw___builtin_choose_expr:
@@ -2869,3 +2871,117 @@
tok::TokenKind Kind = Tok.getKind();
return Actions.ActOnObjCBoolLiteral(ConsumeToken(), Kind);
}
+
+/// Validate availability spec list, emitting diagnostics if necessary. Returns
+/// true if invalid.
+static bool CheckAvailabilitySpecList(Parser &P,
+ ArrayRef<AvailabilitySpec> AvailSpecs) {
+ llvm::SmallSet<StringRef, 4> Platforms;
+ bool HasOtherPlatformSpec = false;
+ bool Valid = true;
+ for (const auto &Spec : AvailSpecs) {
+ if (Spec.isOtherPlatformSpec()) {
+ if (HasOtherPlatformSpec) {
+ P.Diag(Spec.getBeginLoc(), diag::err_availability_query_repeated_star);
+ Valid = false;
+ }
+
+ HasOtherPlatformSpec = true;
+ continue;
+ }
+
+ bool Inserted = Platforms.insert(Spec.getPlatform()).second;
+ if (!Inserted) {
+ // Rule out multiple version specs referring to the same platform.
+ // For example, we emit an error for:
+ // @available(macos 10.10, macos 10.11, *)
+ StringRef Platform = Spec.getPlatform();
+ P.Diag(Spec.getBeginLoc(), diag::err_availability_query_repeated_platform)
+ << Spec.getEndLoc() << Platform;
+ Valid = false;
+ }
+ }
+
+ if (!HasOtherPlatformSpec) {
+ SourceLocation InsertWildcardLoc = AvailSpecs.back().getEndLoc();
+ P.Diag(InsertWildcardLoc, diag::err_availability_query_wildcard_required)
+ << FixItHint::CreateInsertion(InsertWildcardLoc, ", *");
+ return true;
+ }
+
+ return !Valid;
+}
+
+/// Parse availability query specification.
+///
+/// availability-spec:
+/// '*'
+/// identifier version-tuple
+Optional<AvailabilitySpec> Parser::ParseAvailabilitySpec() {
+ if (Tok.is(tok::star)) {
+ return AvailabilitySpec(ConsumeToken());
+ } else {
+ // Parse the platform name.
+ if (Tok.isNot(tok::identifier)) {
+ Diag(Tok, diag::err_avail_query_expected_platform_name);
+ return None;
+ }
+
+ IdentifierLoc *PlatformIdentifier = ParseIdentifierLoc();
+ SourceRange VersionRange;
+ VersionTuple Version = ParseVersionTuple(VersionRange);
+
+ if (Version.empty())
+ return None;
+
+ StringRef Platform = PlatformIdentifier->Ident->getName();
+
+ if (AvailabilityAttr::getPrettyPlatformName(Platform).empty()) {
+ Diag(PlatformIdentifier->Loc,
+ diag::err_avail_query_unrecognized_platform_name)
+ << Platform;
+ return None;
+ }
+
+ return AvailabilitySpec(Version, Platform, PlatformIdentifier->Loc,
+ VersionRange.getEnd());
+ }
+}
+
+ExprResult Parser::ParseAvailabilityCheckExpr(SourceLocation BeginLoc) {
+ assert(Tok.is(tok::kw___builtin_available) ||
+ Tok.isObjCAtKeyword(tok::objc_available));
+
+ // Eat the available or __builtin_available.
+ ConsumeToken();
+
+ BalancedDelimiterTracker Parens(*this, tok::l_paren);
+ if (Parens.expectAndConsume())
+ return ExprError();
+
+ SmallVector<AvailabilitySpec, 4> AvailSpecs;
+ bool HasError = false;
+ while (true) {
+ Optional<AvailabilitySpec> Spec = ParseAvailabilitySpec();
+ if (!Spec)
+ HasError = true;
+ else
+ AvailSpecs.push_back(*Spec);
+
+ if (!TryConsumeToken(tok::comma))
+ break;
+ }
+
+ if (HasError) {
+ SkipUntil(tok::r_paren, StopAtSemi);
+ return ExprError();
+ }
+
+ CheckAvailabilitySpecList(*this, AvailSpecs);
+
+ if (Parens.consumeClose())
+ return ExprError();
+
+ return Actions.ActOnObjCAvailabilityCheckExpr(AvailSpecs, BeginLoc,
+ Parens.getCloseLocation());
+}