[pypy-svn] r32404 - pypy/dist/pypy/rpython/rctypes

[arigo at codespeak.net]

Author: arigo
Date: Sun Sep 17 12:12:50 2006
New Revision: 32404

Modified:
   pypy/dist/pypy/rpython/rctypes/apointer.py
   pypy/dist/pypy/rpython/rctypes/rarray.py
   pypy/dist/pypy/rpython/rctypes/rpointer.py
Log:
Arrays of length 0 are lots of fun.


Modified: pypy/dist/pypy/rpython/rctypes/apointer.py
==============================================================================
--- pypy/dist/pypy/rpython/rctypes/apointer.py	(original)
+++ pypy/dist/pypy/rpython/rctypes/apointer.py	Sun Sep 17 12:12:50 2006
@@ -68,7 +68,9 @@
             # POINTER(varsized_array_type): given that rctypes performs
             # no index checking, this pointer-to-array type is equivalent
             # to a pointer to an array of whatever size.
-            RESTYPE = POINTER(s_arg.ctype_array._type_ * 0)
+            # ('0' is a bad idea, though, as FixedSizeArrays of length 0
+            # tend to say they have impossible items.)
+            RESTYPE = POINTER(s_arg.ctype_array._type_ * 1)
         else:
             # POINTER(constant_ctype) returns the constant annotation
             # corresponding to the POINTER(ctype).

Modified: pypy/dist/pypy/rpython/rctypes/rarray.py
==============================================================================
--- pypy/dist/pypy/rpython/rctypes/rarray.py	(original)
+++ pypy/dist/pypy/rpython/rctypes/rarray.py	Sun Sep 17 12:12:50 2006
@@ -1,5 +1,6 @@
 from ctypes import ARRAY, c_int
-from pypy.rpython.lltypesystem.rstr import string_repr
+from pypy.rpython.error import TyperError
+from pypy.rpython.lltypesystem.rstr import string_repr, emptystr
 from pypy.rpython.rmodel import IntegerRepr, inputconst
 from pypy.rpython.rslice import AbstractSliceRepr
 from pypy.rpython.lltypesystem import lltype
@@ -65,9 +66,12 @@
         assert s_attr.is_constant()
         assert s_attr.const == 'value'
         assert self.r_item.ll_type == lltype.Char  # .value: char arrays only
-        v_box = hop.inputarg(self, 0)
         hop.exception_cannot_occur()
-        return hop.gendirectcall(ll_chararrayvalue, v_box)
+        if self.length == 0:
+            return hop.inputconst(lltype.typeOf(emptystr), emptystr)
+        else:
+            v_box = hop.inputarg(self, 0)
+            return hop.gendirectcall(ll_chararrayvalue, v_box)
 
     def get_c_data_of_item(self, llops, v_array, v_index):
         v_c_array = self.get_c_data(llops, v_array)
@@ -144,9 +148,12 @@
 class __extend__(pairtype(ArrayRepr, AbstractSliceRepr)):
     def rtype_getitem((r_array, r_slic), hop):
         rs = hop.rtyper.type_system.rslice
+        hop.exception_cannot_occur()
         if r_slic == rs.startstop_slice_repr:
             # slicing: char array only
             assert r_array.r_item.ll_type == lltype.Char
+            if r_array.length == 0:
+                return hop.inputconst(lltype.typeOf(emptystr), emptystr)
             v_array, v_slice = hop.inputargs(r_array, rs.startstop_slice_repr)
             return hop.gendirectcall(ll_chararrayslice, v_array, v_slice)
         raise TyperError('getitem does not support slices with %r' % (r_slic,))

Modified: pypy/dist/pypy/rpython/rctypes/rpointer.py
==============================================================================
--- pypy/dist/pypy/rpython/rctypes/rpointer.py	(original)
+++ pypy/dist/pypy/rpython/rctypes/rpointer.py	Sun Sep 17 12:12:50 2006
@@ -37,8 +37,8 @@
         llops.genop('setfield', inputargs)
 
     def initialize_const(self, p, ptr):
-        if ptr is None:   # passed as argument to functions expecting pointers
-            return
+        if not ptr:   # NULL pointer, or literal None passed as argument to
+            return    #  functions expecting pointers
         llcontents = self.r_contents.convert_const(ptr.contents)
         p.c_data[0] = llcontents.c_data
         # the following line is probably pointless, as 'llcontents' will be