Access to MetaData operands

This is not available in the C API, so add functions to extra.cpp:

- `LLVMMetaDataGetOperand` wraps MDNode::getOperand
- `LLVMMetaDataGetNumOperands` wraps MDNode::getNumOperands

llvm/_core.cpp

@@ -608,6 +608,8 @@ _wrap_obj2none(LLVMDeleteBasicBlock, LLVMBasicBlockRef)
 
 _wrap_objlist2obj(LLVMMetaDataGet, LLVMModuleRef, LLVMValueRef, LLVMValueRef)
 _wrap_objstrobj2none(LLVMAddNamedMetadataOperand, LLVMModuleRef, LLVMValueRef)
+_wrap_objint2obj(LLVMMetaDataGetOperand, LLVMValueRef, LLVMValueRef)
+_wrap_obj2obj(LLVMMetaDataGetNumOperands, LLVMValueRef, int)
 
 static PyObject *
 _wLLVMGetNamedMetadataOperands(PyObject *self, PyObject *args)
@@ -1683,6 +1685,8 @@ static PyMethodDef core_methods[] = {
     _method( LLVMMetaDataGet )
     _method( LLVMGetNamedMetadataOperands )
     _method( LLVMAddNamedMetadataOperand )
+    _method( LLVMMetaDataGetOperand )
+    _method( LLVMMetaDataGetNumOperands )
 
     /* Instructions */
     _method( LLVMGetInstructionParent )

llvm/core.py

@@ -1466,6 +1466,18 @@ class MetaData(Value):
     def add_named_operand(module, name, operand):
         _core.LLVMAddNamedMetadataOperand(module.ptr, name, operand.ptr)
 
+    @property
+    def operand_count(self):
+        return _core.LLVMMetaDataGetNumOperands(self.ptr)
+
+    @property
+    def operands(self):
+        """Yields operands of this metadata."""
+        return [self._get_operand(i) for i in range(self.operand_count)]
+
+    def _get_operand(self, i):
+        return _make_value(_core.LLVMMetaDataGetOperand(self.ptr, i))
+
 #===----------------------------------------------------------------------===
 # Instruction
 #===----------------------------------------------------------------------===

llvm/extra.cpp

@@ -149,6 +149,16 @@ LLVMValueRef LLVMMetaDataGet(LLVMModuleRef modref, LLVMValueRef * valrefs,
     return wrap(node);
 }
 
+LLVMValueRef LLVMMetaDataGetOperand(LLVMValueRef mdref, unsigned index)
+{
+    return wrap(llvm::unwrap<llvm::MDNode>(mdref)->getOperand(index));
+}
+
+unsigned LLVMMetaDataGetNumOperands(LLVMValueRef mdref)
+{
+    return llvm::unwrap<llvm::MDNode>(mdref)->getNumOperands();
+}
+
 const char *LLVMGetConstExprOpcodeName(LLVMValueRef inst)
 {
     return llvm::unwrap<llvm::ConstantExpr>(inst)->getOpcodeName();

llvm/extra.h

@@ -65,6 +65,16 @@ void LLVMInstSetMetaData(LLVMValueRef instref, const char* mdkind,
 LLVMValueRef LLVMMetaDataGet(LLVMModuleRef modref, LLVMValueRef * valrefs,
                              unsigned valct);
 
+/*
+ * Wraps MDNode::getOperand()
+ */
+LLVMValueRef LLVMMetaDataGetOperand(LLVMValueRef mdref, unsigned index);
+
+/*
+ * Wraps MDNode::getNumOperands()
+ */
+unsigned LLVMMetaDataGetNumOperands(LLVMValueRef mdref);
+
 /*
  * Wraps ConstantExpr::getOpcodeName()
  */

llvm/test_llvmpy.py

@@ -394,10 +394,13 @@ class TestMetaData(unittest.TestCase):
     # test module metadata
     def test_metadata(self):
         m = Module.new('a')
-        metadata = MetaData.get(m, []) # empty metadata node
+        t = Type.int()
+        metadata = MetaData.get(m, [Constant.int(t, 100)])
         MetaData.add_named_operand(m, 'foo', metadata)
         self.assertEqual(MetaData.get_named_operands(m, 'foo'), [metadata])
         self.assertEqual(MetaData.get_named_operands(m, 'bar'), [])
+        self.assertEqual(len(metadata.operands), 1)
+        self.assertEqual(metadata.operands[0].z_ext_value, 100)
 
 tests.append(TestMetaData)