[pypy-commit] pypy cpyext-gc-support: Support varsized arrays at the end of structs

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: cpyext-gc-support
Changeset: r80356:5dbf9e6ec173
Date: 2015-10-20 17:10 +0200
http://bitbucket.org/pypy/pypy/changeset/5dbf9e6ec173/

Log:	Support varsized arrays at the end of structs

diff --git a/rpython/rtyper/tool/rffi_platform.py b/rpython/rtyper/tool/rffi_platform.py
--- a/rpython/rtyper/tool/rffi_platform.py
+++ b/rpython/rtyper/tool/rffi_platform.py
@@ -313,7 +313,9 @@
                 offset = info['fldofs '  + fieldname]
                 size   = info['fldsize ' + fieldname]
                 sign   = info.get('fldunsigned ' + fieldname, False)
-                if (size, sign) != rffi.size_and_sign(fieldtype):
+                if is_array_nolength(fieldtype):
+                    pass       # ignore size and sign
+                elif (size, sign) != rffi.size_and_sign(fieldtype):
                     fieldtype = fixup_ctype(fieldtype, fieldname, (size, sign))
                 layout_addfield(layout, offset, fieldtype, fieldname)
 
@@ -682,8 +684,14 @@
     def __repr__(self):
         return '<field %s: %s>' % (self.name, self.ctype)
 
+def is_array_nolength(TYPE):
+    return isinstance(TYPE, lltype.Array) and TYPE._hints.get('nolength', False)
+
 def layout_addfield(layout, offset, ctype, prefix):
-    size = _sizeof(ctype)
+    if is_array_nolength(ctype):
+        size = len(layout) - offset    # all the rest of the struct
+    else:
+        size = _sizeof(ctype)
     name = prefix
     i = 0
     while name in layout:
diff --git a/rpython/rtyper/tool/test/test_rffi_platform.py b/rpython/rtyper/tool/test/test_rffi_platform.py
--- a/rpython/rtyper/tool/test/test_rffi_platform.py
+++ b/rpython/rtyper/tool/test/test_rffi_platform.py
@@ -270,6 +270,19 @@
                                        [("d_name", lltype.FixedSizeArray(rffi.CHAR, 1))])
     assert dirent.c_d_name.length == 32
 
+def test_array_varsized_struct():
+    dirent = rffi_platform.getstruct("struct dirent",
+                                       """
+           struct dirent  /* for this example only, not the exact dirent */
+           {
+               int d_off;
+               char d_name[1];
+           };
+                                       """,
+                                       [("d_name", rffi.CArray(rffi.CHAR))])
+    assert rffi.offsetof(dirent, 'c_d_name') == 4
+    assert dirent.c_d_name == rffi.CArray(rffi.CHAR)
+
 def test_has_0001():
     assert rffi_platform.has("x", "int x = 3;")
     assert not rffi_platform.has("x", "")