Merge pull request #32 from tromey/handle-variadic-functions

handle variadic function types

Author: davidmalcolm

docs/tree.rst

@@ -585,6 +585,12 @@ Additional attributes for various :py:class:`gcc.Type` subclasses:
 
    The `type` attribute holds the return type.
 
+   .. py:attribute:: is_variadic
+
+      True if this type represents a variadic function.  Note that for
+      a variadic function, the final `...` argument is not explicitly
+      represented in `argument_types`.
+
    .. py:attribute:: argument_types
 
       A tuple of :py:class:`gcc.Type` instances, representing the function's

gcc-python-tree.c

@@ -564,30 +564,19 @@ PyGccFunction_TypeObj_get_argument_types(struct PyGccTree * self, void *closure)
 
     /* Get length of chain */
     for (size = 0, iter = head;
-         iter && iter != error_mark_node;
+         iter && iter != error_mark_node && iter != void_list_node;
          iter = TREE_CHAIN(iter), size++) {
         /* empty */
     }
 
     /* "size" should now be the length of the chain */
 
-    /* The last element in the list is a VOID_TYPE; don't add this;
-       see dump_function_declaration() in gcc/tree-pretty-print.c */
-    assert(size>0);
-    size--;
-
     result = PyTuple_New(size);
     if (!result) {
         return NULL;
     }
 
-    /* Iterate, but don't visit the final element: */
-    for (i = 0, iter = head;
-         iter && TREE_CHAIN(iter) && iter != error_mark_node;
-         iter = TREE_CHAIN(iter), i++) {
-
-        assert(i<size);
-
+    for (i = 0, iter = head; i < size; iter = TREE_CHAIN(iter), i++) {
 	item = PyGccTree_New(gcc_private_make_tree(TREE_VALUE(iter)));
 	if (!item) {
 	    goto error;
@@ -605,12 +594,36 @@ PyGccFunction_TypeObj_get_argument_types(struct PyGccTree * self, void *closure)
     return NULL;
 }
 
+PyObject *
+PyGccFunction_TypeObj_is_variadic(struct PyGccTree * self, void *closure)
+{
+    tree iter;
+    tree head = TYPE_ARG_TYPES(self->t.inner);
+
+    /* Get length of chain */
+    for (iter = head;
+         iter && iter != error_mark_node && iter != void_list_node;
+         iter = TREE_CHAIN(iter)) {
+        /* empty */
+    }
+
+    if (iter == void_list_node)
+        Py_RETURN_FALSE;
+    Py_RETURN_TRUE;
+}
+
 PyObject *
 PyGccMethodType_get_argument_types(struct PyGccTree * self,void *closure)
 {
     return PyGccFunction_TypeObj_get_argument_types(self, closure);
 }
 
+PyObject *
+PyGccMethodType_is_variadic(struct PyGccTree * self,void *closure)
+{
+    return PyGccFunction_TypeObj_is_variadic(self, closure);
+}
+
 PyObject *
 PyGccConstructor_get_elements(PyObject *self, void *closure)
 {

gcc-python-wrappers.h

@@ -268,6 +268,9 @@ PyGccType_get_sizeof(struct PyGccTree *self, void *closure);
 PyObject *
 PyGccFunction_TypeObj_get_argument_types(struct PyGccTree * self,void *closure);
 
+PyObject *
+PyGccFunction_TypeObj_is_variadic(struct PyGccTree * self, void *closure);
+
 PyObject *
 PyGccConstructor_get_elements(PyObject *self, void *closure);
 
@@ -295,6 +298,9 @@ PyGccIntegerType_repr(struct PyGccTree * self);
 PyObject *
 PyGccMethodType_get_argument_types(struct PyGccTree * self,void *closure);
 
+PyObject *
+PyGccMethodType_is_variadic(struct PyGccTree * self,void *closure);
+
 PyObject *
 PyGccStringConstant_repr(struct PyGccTree * self);
 

generate-tree-c.py

@@ -543,12 +543,20 @@ def add_complex_getter(name, doc):
                                   'PyGccFunction_TypeObj_get_argument_types',
                                   None,
                                   "A tuple of gcc.Type instances, representing the argument types of this function type")
+            getsettable.add_gsdef('is_variadic',
+                                  'PyGccFunction_TypeObj_is_variadic',
+                                  None,
+                                  "Boolean: is this function variadic")
 
         if tree_type.SYM == 'METHOD_TYPE':
             getsettable.add_gsdef('argument_types',
                                   'PyGccMethodType_get_argument_types',
                                   None,
                                   "A tuple of gcc.Type instances, representing the argument types of this method type")
+            getsettable.add_gsdef('is_variadic',
+                                  'PyGccMethodType_is_variadic',
+                                  None,
+                                  "Boolean: is this method variadic")
 
         if tree_type.SYM == 'FUNCTION_DECL':
             getsettable.add_gsdef('fullname',

tests/plugin/function-types/input.c

@@ -18,3 +18,5 @@
 */
 
 typedef int (example_fn_type)(char, float);
+
+typedef int (example_variadic_fn_type)(char, float, ...);

tests/plugin/function-types/script.py

@@ -18,8 +18,8 @@
 import gcc
 import gccutils
 
-def on_finish_unit():
-    fn_type_decl = gccutils.get_global_typedef('example_fn_type')
+def check_fn_type(name):
+    fn_type_decl = gccutils.get_global_typedef(name)
     assert isinstance(fn_type_decl, gcc.TypeDecl)
 
     print('fn_type_decl.name: %r' % fn_type_decl.name)
@@ -30,6 +30,7 @@ def on_finish_unit():
     print('str(fn_type.type): %r' % str(fn_type.type))
     assert isinstance(fn_type.argument_types, tuple)
     print('argument_types: %r' % [str(t) for t in fn_type.argument_types])
+    print('is_variadic: %r' % fn_type.is_variadic)
     try:
         fn_type.sizeof
         assert 0 # an exception should have been raised
@@ -38,6 +39,9 @@ def on_finish_unit():
         print('err: %s' % err)
 
 
+def on_finish_unit():
+    check_fn_type('example_fn_type')
+    check_fn_type('example_variadic_fn_type')
 
 gcc.register_callback(gcc.PLUGIN_FINISH_UNIT,
                       on_finish_unit)

tests/plugin/function-types/stdout.txt

@@ -2,4 +2,11 @@ fn_type_decl.name: 'example_fn_type'
 str(fn_type): 'int example_fn_type (char, float)'
 str(fn_type.type): 'int'
 argument_types: ['char', 'float']
+is_variadic: False
 err: type "int example_fn_type (char, float)" does not have a "sizeof"
+fn_type_decl.name: 'example_variadic_fn_type'
+str(fn_type): 'int example_variadic_fn_type (char, float, ...)'
+str(fn_type.type): 'int'
+argument_types: ['char', 'float']
+is_variadic: True
+err: type "int example_variadic_fn_type (char, float, ...)" does not have a "sizeof"