[libclang] Restore old clang_Cursor_isAnonymous behaviour

D54996 Changed the behaviour of clang_Cursor_isAnonymous, but there is no alternative available to get the old behaviour in some cases, which is essential for determining if a record is syntactically accessible, e.g.

struct {
  int x;
  int y;
} foo;

struct {
  struct {
    int x;
    int y;
  };
} bar;

void fun(struct { int x; int y; } *param);
The only 'anonymous' struct here is the one nested in bar, since there is
no way to reference the struct itself, only the fields within. Though the
anonymity applies to the instance itself, not the type.

To avoid confusion, I have added a new function called clang_Cursor_isAnonymousRecordDecl
which has the old behaviour of clang_Cursor_isAnonymous (and updated the doc
for the latter as well, which was seemingly forgotten).

Patch by Jorn Vernee.

Differential Revision: https://reviews.llvm.org/D61232

llvm-svn: 359448

clang/include/clang-c/Index.h

@@ -32,7 +32,7 @@
  * compatible, thus CINDEX_VERSION_MAJOR is expected to remain stable.
  */
 #define CINDEX_VERSION_MAJOR 0
-#define CINDEX_VERSION_MINOR 55
+#define CINDEX_VERSION_MINOR 56
 
 #define CINDEX_VERSION_ENCODE(major, minor) ( \
       ((major) * 10000)                       \
@@ -3920,11 +3920,17 @@ CINDEX_LINKAGE CXType clang_Type_getModifiedType(CXType T);
  */
 CINDEX_LINKAGE long long clang_Cursor_getOffsetOfField(CXCursor C);
 
+/**
+ * Determine whether the given cursor represents an anonymous
+ * tag or namespace
+ */
+CINDEX_LINKAGE unsigned clang_Cursor_isAnonymous(CXCursor C);
+
 /**
  * Determine whether the given cursor represents an anonymous record
  * declaration.
  */
-CINDEX_LINKAGE unsigned clang_Cursor_isAnonymous(CXCursor C);
+CINDEX_LINKAGE unsigned clang_Cursor_isAnonymousRecordDecl(CXCursor C);
 
 enum CXRefQualifierKind {
   /** No ref-qualifier was provided. */

clang/test/Index/print-type.c

@@ -15,6 +15,20 @@ int f2(int incompletearray[]);
 enum Enum{i}; enum Enum elaboratedEnumType();
 struct Struct{}; struct Struct elaboratedStructType();
 
+struct {
+  int x;
+  int y;
+} foo;
+
+struct {
+  struct {
+    int x;
+    int y;
+  };
+} bar;
+
+void fun(struct { int x; int y; } *param);
+
 // RUN: c-index-test -test-print-type %s | FileCheck %s
 // CHECK: FunctionDecl=f:3:6 (Definition) [type=int *(int *, char *, FooType, int *, void (*)(int))] [typekind=FunctionProto] [canonicaltype=int *(int *, char *, int, int *, void (*)(int))] [canonicaltypekind=FunctionProto] [resulttype=int *] [resulttypekind=Pointer] [args= [int *] [Pointer] [char *] [Pointer] [FooType] [Typedef] [int [5]] [ConstantArray] [void (*)(int)] [Pointer]] [isPOD=0]
 // CHECK: ParmDecl=p:3:13 (Definition) [type=int *] [typekind=Pointer] [isPOD=1] [pointeetype=int] [pointeekind=Int]
@@ -53,3 +67,7 @@ struct Struct{}; struct Struct elaboratedStructType();
 // CHECK: StructDecl=Struct:16:8 (Definition) [type=struct Struct] [typekind=Record] [isPOD=1]
 // CHECK: FunctionDecl=elaboratedStructType:16:32 [type=struct Struct ()] [typekind=FunctionNoProto] [canonicaltype=struct Struct ()] [canonicaltypekind=FunctionNoProto] [resulttype=struct Struct] [resulttypekind=Elaborated] [isPOD=0]
 // CHECK: TypeRef=struct Struct:16:8 [type=struct Struct] [typekind=Record] [isPOD=1]
+// CHECK: StructDecl=:18:1 (Definition) [type=struct (anonymous at {{.*}}print-type.c:18:1)] [typekind=Record] [isPOD=1] [nbFields=2] [isAnon=1] [isAnonRecDecl=0]
+// CHECK: StructDecl=:23:1 (Definition) [type=struct (anonymous at {{.*}}print-type.c:23:1)] [typekind=Record] [isPOD=1] [nbFields=1] [isAnon=1] [isAnonRecDecl=0]
+// CHECK: StructDecl=:24:3 (Definition) [type=struct (anonymous at {{.*}}print-type.c:24:3)] [typekind=Record] [isPOD=1] [nbFields=2] [isAnon=1] [isAnonRecDecl=1]
+// CHECK: StructDecl=:30:10 (Definition) [type=struct (anonymous at {{.*}}print-type.c:30:10)] [typekind=Record] [isPOD=1] [nbFields=2] [isAnon=1] [isAnonRecDecl=0]

clang/tools/c-index-test/c-index-test.c

@@ -1665,6 +1665,12 @@ static enum CXChildVisitResult PrintType(CXCursor cursor, CXCursor p,
       }
     }
 
+    /* Print if it is an anonymous record decl */
+    {
+      unsigned isAnonRecDecl = clang_Cursor_isAnonymousRecordDecl(cursor);
+      printf(" [isAnonRecDecl=%d]", isAnonRecDecl);
+    }
+
     printf("\n");
   }
   return CXChildVisit_Recurse;

clang/tools/libclang/CXType.cpp

@@ -1253,6 +1253,16 @@ unsigned clang_Cursor_isAnonymous(CXCursor C){
 
   return 0;
 }
+
+unsigned clang_Cursor_isAnonymousRecordDecl(CXCursor C){
+  if (!clang_isDeclaration(C.kind))
+    return 0;
+  const Decl *D = cxcursor::getCursorDecl(C);
+  if (const RecordDecl *FD = dyn_cast_or_null<RecordDecl>(D))
+    return FD->isAnonymousStructOrUnion();
+  return 0;
+}
+
 CXType clang_Type_getNamedType(CXType CT){
   QualType T = GetQualType(CT);
   const Type *TP = T.getTypePtrOrNull();