Implement support for anonymous structs and unions in C. Both C and
C++ handle anonymous structs/unions in the same way. Addresses several
bugs:

  <rdar://problem/6259534>
  <rdar://problem/6481130>
  <rdar://problem/6483159>

The test case in PR clang/1750 now passes with -fsyntax-only, but
CodeGen for inline assembler still fails.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62112 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/anonymous-struct-union.c b/test/Sema/anonymous-struct-union.c
new file mode 100644
index 0000000..72790c9
--- /dev/null
+++ b/test/Sema/anonymous-struct-union.c
@@ -0,0 +1,82 @@
+// RUN: clang -fsyntax-only -verify %s
+struct X {
+  union {
+    float f3;
+    double d2;
+  } named;
+
+  union {
+    int i;
+    float f;
+    
+    union {
+      float f2;
+      double d;
+    };
+  };
+
+  struct {
+    int a;
+    float b;
+  };
+};
+
+void test_unqual_references(struct X x, const struct X xc) {
+  x.i = 0;
+  x.f = 0.0;
+  x.f2 = x.f;
+  x.d = x.f;
+  x.f3 = 0; // expected-error{{no member named 'f3'}}
+  x.a = 0;
+
+  xc.d = 0.0; // expected-error{{read-only variable is not assignable}}
+  xc.f = 0; // expected-error{{read-only variable is not assignable}}
+  xc.a = 0; // expected-error{{read-only variable is not assignable}}
+}
+
+
+struct Redecl {
+  int x; // expected-note{{previous declaration is here}}
+  struct y { };
+
+  union {
+    int x; // expected-error{{member of anonymous union redeclares 'x'}}
+    float y;
+    double z; // expected-note{{previous declaration is here}}
+    double zz; // expected-note{{previous declaration is here}}
+  };
+
+  int z; // expected-error{{duplicate member 'z'}}
+  void zz(); // expected-error{{duplicate member 'zz'}} \
+            //  expected-error{{field 'zz' declared as a function}}
+};
+
+union { // expected-error{{anonymous unions must be struct or union members}}
+  int int_val;
+  float float_val;
+};
+
+static union { // expected-error{{anonymous unions must be struct or union members}}
+  int int_val2;
+  float float_val2;
+};
+
+void f() {
+  int_val2 = 0; // expected-error{{use of undeclared identifier}}
+  float_val2 = 0.0; // expected-error{{use of undeclared identifier}}
+}
+
+void g() {
+  union { // expected-error{{anonymous unions must be struct or union members}}
+    int i;
+    float f2;
+  };
+  i = 0; // expected-error{{use of undeclared identifier}}
+  f2 = 0.0; // expected-error{{use of undeclared identifier}}
+}
+
+// <rdar://problem/6483159>
+struct s0 { union { int f0; }; };
+
+// <rdar://problem/6481130>
+typedef struct { }; // expected-error{{declaration does not declare anything}}