const for pointers

This commit needs Cython > 0.18 as support for
const pointers was just recently added with commit
5e1497371ee70fffb2deb6c7dab136cf6684f2df [1].

[1] cython/cython@5e14973

README.rst

@@ -11,6 +11,7 @@ Requirements
 ------------
 
 * the libclang library (libclang.so, libclang.dylib or libclang.dll), contained in `llvm binary distribution <http://llvm.org/releases/download.html>`_ needs to be somewhere on the binary search path.
+* if your header files contain const definitions, you need a Cython > 0.18 in order to be able to compile it
 
 
 Getting started

cwrap/backend/cw_ast.py

@@ -1470,9 +1470,11 @@ class Pointer(ctype):
     value : a ctype node.
 
     """
-    def init(self, value):
+    def init(self, value, const=False, volatile=False):
         assert_ctype(value, 'value')
         self.value = value
+        self.const = const
+        self.volatile = volatile
 
 
 class Array(ctype):

cwrap/backend/renderer.py

@@ -1063,6 +1063,8 @@ def extract_reference_types(self, node):
 
         while isinstance(node, (cw_ast.Pointer, cw_ast.Array)):
             if isinstance(node, cw_ast.Pointer):
+                if node.const:
+                    mods.append('const')
                 mods.append('*')
             else:
                 dim = node.dim
@@ -1073,7 +1075,8 @@ def extract_reference_types(self, node):
 
         i = 0
         while i < (len(mods) - 1):
-            if mods[i][0] == '[' and mods[i][-1] == ']':
+            if (mods[i][0] == '[' and mods[i][-1] == ']') or \
+                    mods[i] == 'const' or mods[i + 1] == 'const':
                 i += 1
             elif mods[i] != mods[i + 1]:
                 mods.insert(i + 1, '()')
@@ -1091,6 +1094,8 @@ def apply_reference_types(self, mods, name):
                 name = sub_str % (mod, name)
             elif mod == '()':
                 name = '(%s)' % name
+            elif mod == 'const':
+                name = 'const %s' % name
             else:
                 name = sub_str % (name, mod)
         return name

cwrap/frontends/clang/ast_transforms.py

@@ -424,8 +424,12 @@ def translate_ArrayType(self, array):
         return cw_ast.Array(self.visit_translate(array.typ), dim)
 
     def translate_CvQualifiedType(self, qual):
-        return cw_ast.TypeName(cw_ast.Name(qual.typ.name, cw_ast.Param),
-                               qual.const, qual.volatile)
+        # The `const` and `volatile` attributes are defined for `TypeName`
+        # and `Pointer`
+        cvtype = self.visit_translate(qual.typ)
+        cvtype.const = qual.const
+        cvtype.volatile = qual.volatile
+        return cvtype
 
     def translate_Typedef(self, typedef):
         return cw_ast.TypeName(cw_ast.Name(typedef.name, cw_ast.Param))

cwrap/frontends/clang/clang_parser.py

@@ -178,12 +178,18 @@ def type_to_c_ast_type(self, t, level, recurse = True):
             return c_ast.ArrayType(a, 0, t.element_count-1), None
 
         elif kind is TypeKind.TYPEDEF:
-            return c_ast.FundamentalType(t.get_declaration().spelling), None #t.get_declaration().hash
+            const = t.is_const_qualified()
+            volatile = t.is_volatile_qualified()
+            fundtype = c_ast.FundamentalType(t.get_declaration().spelling)
+            return c_ast.CvQualifiedType(fundtype, const, volatile), None
 
         elif kind is TypeKind.POINTER:
+            const = t.is_const_qualified()
+            volatile = t.is_volatile_qualified()
             ptrtype, foo = self.type_to_c_ast_type(t.get_pointee(), level+1)
             if ptrtype is not None:
-                return c_ast.PointerType(ptrtype, None, None), None
+                ptrtype = c_ast.PointerType(ptrtype, None, None)
+                return c_ast.CvQualifiedType(ptrtype, const, volatile), None
 
         elif kind is TypeKind.LVALUEREFERENCE:
             reftype, foo = self.type_to_c_ast_type(t.get_pointee(), level+1)

test/data/const_argument.h

@@ -1 +1,6 @@
 int foo(const char* bar);
+typedef struct my_st my_t
+int baz(const my_t **foo);
+int bar(const my_t *const *something);
+int another(my_t *const *one);
+int yet(my_t *const *const another);

test/data/const_argument.pxd

@@ -1,2 +1,9 @@
 cdef extern from "const_argument.h":
     int foo(const char *bar)
+    cdef struct my_st:
+        pass
+    ctypedef my_st my_t
+    int baz(const my_t **foo)
+    int bar(const my_t *const *something)
+    int another(my_t *const *one)
+    int yet(my_t *const *const another)