pp handles large objects better.

Try using decompyle3 on 3.7 and 3.8

Author: rocky

__pkginfo__.py

@@ -23,11 +23,16 @@
 
 import sys
 
+decompiler = "uncompyle6 >= 3.7.4"
+
 SYS_VERSION = sys.version_info[0:2]
 if SYS_VERSION <= (3, 2):
     pygments_version = "== 1.6"
 else:
     pygments_version = ">= 2.2.0"
+    if (3, 7) <= SYS_VERSION <= (3, 8):
+        decompiler = "decompyle3 >= 3.7.4"
+
 
 # Python-version | package  | last-version |
 # ------------------------------------------
@@ -78,7 +83,7 @@
     "spark_parser >= 1.8.9, <1.9.0",
     "tracer >= 0.3.2",
     "term-background >= 1.0.1",
-    "uncompyle6 >= 3.7.4",
+    decompiler,
 ]
 license = "GPL3"
 mailing_list = "python-debugger@googlegroups.com"

trepan/__main__.py

@@ -145,12 +145,18 @@ def main(dbg=None, sys_argv=list(sys.argv)):
                         "Python file name embedded in code %s not found" % try_file
                     )
             except IOError:
+                decompiler = "uncompyle6"
                 try:
-                    from uncompyle6 import decompile_file
+                    if 3.7 <= PYTHON_VERSION <= 3.8:
+                        from uncompyle6 import decompile_file
+                    else:
+                        from decompyle3 import decompile_file
+
+                        decompiler = "decompyle3"
                 except ImportError:
                     print(
-                        "%s: Compiled python file '%s', but uncompyle6 not found"
-                        % (__title__, mainpyfile),
+                        "%s: Compiled python file '%s', but %s not found"
+                        % (__title__, mainpyfile, decompiler),
                         file=sys.stderr,
                     )
                     sys.exit(1)

trepan/lib/deparse.py

@@ -4,8 +4,15 @@
 import sys, tempfile
 from io import StringIO
 from hashlib import sha1
-from uncompyle6.semantics.linemap import code_deparse_with_map
-from uncompyle6.semantics.fragments import deparsed_find, code_deparse
+from xdis import PYTHON_VERSION
+
+if 3.7 <= PYTHON_VERSION <= 3.8:
+    from decompyle3.semantics.linemap import code_deparse_with_map
+    from decompyle3.semantics.fragments import deparsed_find, code_deparse
+else:
+    from uncompyle6.semantics.linemap import code_deparse_with_map
+    from uncompyle6.semantics.fragments import deparsed_find, code_deparse
+
 import pyficache
 
 # FIXME remap filename to a short name.

trepan/lib/pp.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-#   Copyright (C) 2009, 2013, 2015-2016, 2020 Rocky Bernstein
+#   Copyright (C) 2009, 2013, 2015-2016, 2020-2021 Rocky Bernstein
 #
 #  This program is free software: you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -17,6 +17,42 @@
 import pprint
 from columnize import columnize
 
+# Maximum length of strings
+MAX_PP_STRLEN = 100
+
+# Maximum number of keys in dictionary
+MAX_PP_COUNT = 20
+
+# Maximum total formatted string
+MAX_PP_LENGTH = 2000
+
+
+def truncate_length(obj, length=MAX_PP_COUNT):
+    """If `obj` is something that has more than `length` items,
+    then truncate it to the first `length` items.
+    """
+    if isinstance(obj, dict):
+        new_obj = dict((k[:length], v) for k, v in sorted(obj.items()))
+        # We hope zzz will be appear at the end of the sorted list.
+        new_obj.update({"zzz...": "..."})
+        return new_obj
+    elif hasattr(obj, "__getitem__"):
+        return list(obj[:length]) + ["..."]
+    return obj
+
+
+class SafePP(pprint.PrettyPrinter):
+    def _format(self, obj, *args, **kwargs):
+        if isinstance(obj, str):
+            if len(obj) > MAX_PP_STRLEN:
+                obj = obj[:MAX_PP_STRLEN] + "..."
+                pass
+            pass
+        elif hasattr(obj, "__len__") and len(obj) > MAX_PP_COUNT:
+            obj = truncate_length(obj)
+
+        return pprint.PrettyPrinter._format(self, obj, *args, **kwargs)
+
 
 def pp(val, display_width, msg_nocr, msg, prefix=None):
     if prefix is not None:
@@ -30,11 +66,11 @@ def pp(val, display_width, msg_nocr, msg, prefix=None):
     if isinstance(val, list) or isinstance(val, tuple):
         if not pprint_simple_array(val, display_width, msg_nocr, msg, "  "):
             print("Can't print_simple_array")
-            msg("  " + pprint.pformat(val))
+            msg("  " + pprint.pformat(val)[:MAX_PP_LENGTH])
             pass
         pass
     else:
-        msg("  " + pprint.pformat(val))
+        msg("  " + SafePP().pformat(val)[:MAX_PP_LENGTH])
         pass
     return
 
@@ -43,7 +79,7 @@ def pp(val, display_width, msg_nocr, msg, prefix=None):
 # Possibly some will go into columnize.
 def pprint_simple_array(val, displaywidth, msg_nocr, msg, lineprefix=""):
     """Try to pretty print a simple case where a list is not nested.
-    Return True if we can do it and False if not. """
+    Return True if we can do it and False if not."""
 
     if not (isinstance(val, list) or isinstance(val, tuple)):
         return False
@@ -88,8 +124,8 @@ def msg(m):
     pp(x, 20, msg_nocr, msg, "x = ")
     pp(x, 32, msg_nocr, msg, "x = ")
     x = [i for i in range(30)]
-    l = locals().keys()
-    for k in sorted(l):
+    ll = locals().keys()
+    for k in sorted(ll):
         pp(eval(k), 80, msg_nocr, msg, prefix="%s =" % k)
         pass
     pass

trepan/processor/cmdfns.py

@@ -19,7 +19,7 @@
 """
 import os, sys, tempfile
 import pyficache
-from xdis import IS_PYPY
+from xdis import IS_PYPY, PYTHON_VERSION
 
 
 def source_tempfile_remap(prefix, text, tempdir=None):
@@ -35,9 +35,15 @@ def source_tempfile_remap(prefix, text, tempdir=None):
 
 def deparse_fn(code):
     try:
-        from uncompyle6.semanitcs.linemap import (
-            deparse_code_with_fragments_and_map as deparse_code,
-        )
+        if 3.7 <= PYTHON_VERSION <= 3.8:
+            from uncompyle6.semantics.linemap import (
+                deparse_code_with_fragments_and_map as deparse_code,
+            )
+        else:
+            from decompile3.semantics.linemap import (
+                deparse_code_with_fragments_and_map as deparse_code,
+            )
+
     except ImportError:
         return None
     sys_version = sys.version[:5]

trepan/processor/command/base_cmd.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-#  Copyright (C) 2009-2010, 2012-2013, 2015 Rocky Bernstein
+#  Copyright (C) 2009-2010, 2012-2013, 2015, 2021 Rocky Bernstein
 #
 #  This program is free software: you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -98,10 +98,10 @@ def msg(self, msg, opts={}):
             pass
         return None
 
-    def msg_nocr(self, msg, opts={}):
+    def msg_nocr(self, msg: str, opts={}):
         """ Convenience short-hand for self.debugger.intf[-1].msg_nocr """
         try:
-            return self.debugger.intf[-1].msg_nocr(msg)
+            return self.debugger.intf[-1].msg_nocr(msg[:1000])
         except EOFError:
             # FIXME: what do we do here?
             pass

trepan/processor/command/deparse.py

@@ -59,7 +59,7 @@ class DeparseCommand(DebuggerCommand):
 `disassemble`, `list`, and `set highlight`
 """
 
-    short_help = "Deparse source via uncompyle6"
+    short_help = "Deparse source via uncompyle6/decompyle3"
     DebuggerCommand.setup(locals(), category="data", max_args=10, need_stack=True)
 
     def print_text(self, text):

trepan/processor/command/deval.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-#  Copyright (C) 2017-2018, 2020 Rocky Bernstein
+#  Copyright (C) 2017-2018, 2020-2021 Rocky Bernstein
 #
 #  This program is free software: you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -16,10 +16,15 @@
 
 # Our local modules
 from sys import version_info
+from xdis import IS_PYPY, PYTHON_VERSION
 from trepan.processor.command.base_cmd import DebuggerCommand
-from uncompyle6.semantics.fragments import deparse_code
-from xdis import IS_PYPY
-from uncompyle6.semantics.fragments import deparsed_find
+
+if 3.7 <= PYTHON_VERSION <= 3.8:
+    from decompyle3.semantics.fragments import deparse_code
+    from decompyle3.semantics.fragments import deparsed_find
+else:
+    from uncompyle6.semantics.fragments import deparse_code
+    from uncompyle6.semantics.fragments import deparsed_find
 
 
 class DEvalCommand(DebuggerCommand):