[Parser][ObjC++] Improve diagnostics and recovery when C++ keywords are used

as identifiers in Objective-C++

This commit improves the 'expected identifier' errors that are presented when a
C++ keyword is used as an identifier in Objective-C++ by mentioning that this is
a C++ keyword in the diagnostic message. It also improves the error recovery:
the parser will now treat the C++ keywords as identifiers to prevent unrelated
parsing errors.

rdar://20626062

Differential Revision: https://reviews.llvm.org/D26503

llvm-svn: 299950

1 files changed, 62 insertions, 0 deletions

diff --git a/clang/test/Parser/objc-cxx-keyword-identifiers.mm b/clang/test/Parser/objc-cxx-keyword-identifiers.mm
new file mode 100644
index 00000000000..6791f0d3732
--- /dev/null
+++ b/clang/test/Parser/objc-cxx-keyword-identifiers.mm
@@ -0,0 +1,62 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wno-objc-root-class -Wno-incomplete-implementation -triple x86_64-apple-macosx10.10.0 -verify %s
+
+// rdar://20626062
+
+struct S {
+  int throw; // expected-error {{expected member name or ';' after declaration specifiers; 'throw' is a keyword in Objective-C++}}
+};
+
+@interface class // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
+@end
+
+@interface Bar: class // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
+@end
+
+@protocol P // ok
+@end
+
+@protocol new // expected-error {{expected identifier; 'new' is a keyword in Objective-C++}}
+@end
+
+@protocol P2, delete; // expected-error {{expected identifier; 'delete' is a keyword in Objective-C++}}
+
+@class Foo, try; // expected-error {{expected identifier; 'try' is a keyword in Objective-C++}}
+
+@interface Foo
+
+@property (readwrite, nonatomic) int a, b, throw; // expected-error {{expected member name or ';' after declaration specifiers; 'throw' is a keyword in Objective-C++}}
+
+-foo:(int)class; // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
++foo:(int)constexpr; // expected-error {{expected identifier; 'constexpr' is a keyword in Objective-C++}}
+
+@end
+
+@interface Foo () <P, new> // expected-error {{expected identifier; 'new' is a keyword in Objective-C++}}
+@end
+
+@implementation Foo
+
+@synthesize a = _a; // ok
+@synthesize b = virtual; // expected-error {{expected identifier; 'virtual' is a keyword in Objective-C++}}
+
+@dynamic throw; // expected-error {{expected identifier; 'throw' is a keyword in Objective-C++}}
+
+-foo:(int)class { // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
+}
+
+@end
+
+@implementation class // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
+@end
+
+@implementation Bar: class // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
+@end
+
+@compatibility_alias C Foo; // ok
+@compatibility_alias const_cast Bar; // expected-error {{expected identifier; 'const_cast' is a keyword in Objective-C++}}
+@compatibility_alias C2 class; // expected-error {{expected identifier; 'class' is a keyword in Objective-C++}}
+
+void func() {
+  (void)@protocol(P); // ok
+  (void)@protocol(delete); // expected-error {{expected identifier; 'delete' is a keyword in Objective-C++}}
+}