Author: Antonio Cuni <anto.c...@gmail.com>
Branch:
Changeset: r46255:d5704088efa9
Date: 2011-08-03 19:54 +0200
http://bitbucket.org/pypy/pypy/changeset/d5704088efa9/
Log: a macro for gdb which gives you the rpython type of an expression
diff --git a/pypy/tool/gdb_pypy.py b/pypy/tool/gdb_pypy.py
new file mode 100644
--- /dev/null
+++ b/pypy/tool/gdb_pypy.py
@@ -0,0 +1,78 @@
+"""
+Some convenience macros for gdb. Load them by putting this file somewhere in
+the path and then, from gdb:
+
+(gdb) python import pypy_gdb
+
+Or, alternatively:
+
+(gdb) python execfile('/path/to/pypy_gdb.py')
+"""
+
+import sys
+import gdb
+
+def load_typeids():
+ """
+ Returns a mapping offset --> description
+ """
+ typeids = {}
+ for line in open('typeids.txt'):
+ member, descr = map(str.strip, line.split(None, 1))
+ expr = "((char*)(&pypy_g_typeinfo.%s)) - (char*)&pypy_g_typeinfo" %
member
+ offset = int(gdb.parse_and_eval(expr))
+ typeids[offset] = descr
+ return typeids
+
+class RPyType (gdb.Command):
+ """
+ Prints the RPython type of the expression (remember to dereference it!)
+ It assumes to find ``typeids.txt`` in the current directory.
+ E.g.:
+
+ (gdb) rpy_type *l_v123
+ GcStruct pypy.foo.Bar { super, inst_xxx, inst_yyy }
+ """
+
+ def __init__(self):
+ gdb.Command.__init__(self, "rpy_type", gdb.COMMAND_NONE)
+
+ ## # some magic code to automatically reload the python file while
developing
+ ## def invoke(self, arg, from_tty):
+ ## sys.path.insert(0, '')
+ ## import gdb_pypy
+ ## reload(gdb_pypy)
+ ## self.__class__ = gdb_pypy.RPyType
+ ## self.do_invoke(arg, from_tty)
+
+ def invoke(self, arg, from_tty):
+ obj = gdb.parse_and_eval(arg)
+ hdr = self.get_gc_header(obj)
+ tid = hdr['h_tid']
+ offset = tid & 0xFFFFFFFF # 64bit only
+ offset = int(offset) # convert from gdb.Value to python int
+ typeids = load_typeids()
+ if offset in typeids:
+ print typeids[offset]
+ else:
+ print 'Cannot find the type with offset %d' % offset
+
+ def get_first_field_if(self, obj, suffix):
+ ctype = obj.type
+ field = ctype.fields()[0]
+ if field.name.endswith(suffix):
+ return obj[field.name]
+ return None
+
+ def get_super(self, obj):
+ return self.get_first_field_if(obj, '_super')
+
+ def get_gc_header(self, obj):
+ while True:
+ sup = self.get_super(obj)
+ if sup is None:
+ break
+ obj = sup
+ return self.get_first_field_if(obj, '_gcheader')
+
+RPyType() # side effects
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