[LLVM-C] [OCaml] Expose Type::subtypes.

The C functions added are LLVMGetNumContainedTypes and
LLVMGetSubtypes.

The OCaml function added is Llvm.subtypes.

Patch by Ekaterina Vaartis.

Differential Revision: https://reviews.llvm.org/D33677

llvm-svn: 304709

bindings/ocaml/llvm/llvm.ml

@@ -459,6 +459,8 @@ external is_packed : lltype -> bool = "llvm_is_packed"
 external is_opaque : lltype -> bool = "llvm_is_opaque"
 
 (*--... Operations on pointer, vector, and array types .....................--*)
+
+external subtypes : lltype -> lltype array = "llvm_subtypes"
 external array_type : lltype -> int -> lltype = "llvm_array_type"
 external pointer_type : lltype -> lltype = "llvm_pointer_type"
 external qualified_pointer_type : lltype -> int -> lltype

bindings/ocaml/llvm/llvm.mli

@@ -658,6 +658,9 @@ val is_opaque : lltype -> bool
 
 (** {7 Operations on pointer, vector, and array types} *)
 
+(** [subtypes ty] returns [ty]'s subtypes *)
+val subtypes : lltype -> lltype array
+
 (** [array_type ty n] returns the array type containing [n] elements of type
     [ty]. See the method [llvm::ArrayType::get]. *)
 val array_type : lltype -> int -> lltype

bindings/ocaml/llvm/llvm_ocaml.c

@@ -506,6 +506,20 @@ CAMLprim value llvm_is_opaque(LLVMTypeRef StructTy) {
 
 /*--... Operations on array, pointer, and vector types .....................--*/
 
+/* lltype -> lltype array */
+CAMLprim value llvm_subtypes(LLVMTypeRef Ty) {
+    CAMLparam0();
+    CAMLlocal1(Arr);
+
+    unsigned Size = LLVMGetNumContainedTypes(Ty);
+
+    Arr = caml_alloc(Size, 0);
+
+    LLVMGetSubtypes(Ty, (LLVMTypeRef *) Arr);
+
+    CAMLreturn(Arr);
+}
+
 /* lltype -> int -> lltype */
 CAMLprim LLVMTypeRef llvm_array_type(LLVMTypeRef ElementTy, value Count) {
   return LLVMArrayType(ElementTy, Int_val(Count));

include/llvm-c/Core.h

@@ -1039,6 +1039,20 @@ LLVMBool LLVMIsOpaqueStruct(LLVMTypeRef StructTy);
  */
 LLVMTypeRef LLVMGetElementType(LLVMTypeRef Ty);
 
+/**
+ * Returns type's subtypes
+ *
+ * @see llvm::Type::subtypes()
+ */
+void LLVMGetSubtypes(LLVMTypeRef Tp, LLVMTypeRef *Arr);
+
+/**
+ *  Return the number of types in the derived type.
+ *
+ * @see llvm::Type::getNumContainedTypes()
+ */
+unsigned LLVMGetNumContainedTypes(LLVMTypeRef Tp);
+
 /**
  * Create a fixed size array type that refers to a specific type.
  *

lib/IR/Core.cpp

@@ -568,6 +568,14 @@ LLVMTypeRef LLVMGetTypeByName(LLVMModuleRef M, const char *Name) {
 
 /*--.. Operations on array, pointer, and vector types (sequence types) .....--*/
 
+void LLVMGetSubtypes(LLVMTypeRef Tp, LLVMTypeRef *Arr) {
+    int i = 0;
+    for (auto *T : unwrap(Tp)->subtypes()) {
+        Arr[i] = wrap(T);
+        i++;
+    }
+}
+
 LLVMTypeRef LLVMArrayType(LLVMTypeRef ElementType, unsigned ElementCount) {
   return wrap(ArrayType::get(unwrap(ElementType), ElementCount));
 }
@@ -587,6 +595,10 @@ LLVMTypeRef LLVMGetElementType(LLVMTypeRef WrappedTy) {
   return wrap(cast<SequentialType>(Ty)->getElementType());
 }
 
+unsigned LLVMGetNumContainedTypes(LLVMTypeRef Tp) {
+    return unwrap(Tp)->getNumContainedTypes();
+}
+
 unsigned LLVMGetArrayLength(LLVMTypeRef ArrayTy) {
   return unwrap<ArrayType>(ArrayTy)->getNumElements();
 }

test/Bindings/OCaml/core.ml

@@ -66,6 +66,16 @@ let suite name f =
 let filename = Sys.argv.(1)
 let m = create_module context filename
 
+(*===-- Contained types  --------------------------------------------------===*)
+
+let test_contained_types () =
+  let pointer_i32 = pointer_type i32_type in
+  insist (i32_type = (Array.get (subtypes pointer_i32) 0));
+
+  let ar = struct_type context [| i32_type; i8_type |] in
+  insist (i32_type = (Array.get (subtypes ar)) 0);
+  insist (i8_type = (Array.get (subtypes ar)) 1)
+
 
 (*===-- Conversion --------------------------------------------------------===*)
 
@@ -1533,6 +1543,7 @@ let test_writer () =
 (*===-- Driver ------------------------------------------------------------===*)
 
 let _ =
+  suite "contained types"  test_contained_types;
   suite "conversion"       test_conversion;
   suite "target"           test_target;
   suite "constants"        test_constants;