From 46ed89b7a32f2c415dc12a077e2bbc8bbf973eb9 Mon Sep 17 00:00:00 2001 From: Luuk van Dijk Date: Fri, 23 Sep 2011 10:28:02 +0200 Subject: [PATCH] runtime: gdb support: gracefully handle not being able to find types The Dwarf info has the full typenames, the go *struct runtime.commonType has the short name. A more permanent fix would link the two together but this way the user gets useable stack traces for now. R=rsc CC=golang-dev https://golang.org/cl/5097046 --- src/pkg/runtime/runtime-gdb.py | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/src/pkg/runtime/runtime-gdb.py b/src/pkg/runtime/runtime-gdb.py index a96f3f3828..f815e102c1 100644 --- a/src/pkg/runtime/runtime-gdb.py +++ b/src/pkg/runtime/runtime-gdb.py @@ -187,6 +187,8 @@ def lookup_type(name): def iface_dtype(obj): "Decode type of the data field of an eface or iface struct." + # known issue: dtype_name decoded from runtime.commonType is "nested.Foo" + # but the dwarf table lists it as "full/path/to/nested.Foo" if is_iface(obj): go_type_ptr = obj['tab']['_type'] @@ -198,13 +200,30 @@ def iface_dtype(obj): ct = gdb.lookup_type("struct runtime.commonType").pointer() dynamic_go_type = go_type_ptr['ptr'].cast(ct).dereference() dtype_name = dynamic_go_type['string'].dereference()['str'].string() - type_size = int(dynamic_go_type['size']) - uintptr_size = int(dynamic_go_type['size'].type.sizeof) # size is itself an uintptr + dynamic_gdb_type = lookup_type(dtype_name) - if type_size > uintptr_size: - dynamic_gdb_type = dynamic_gdb_type.pointer() + if dynamic_gdb_type: + type_size = int(dynamic_go_type['size']) + uintptr_size = int(dynamic_go_type['size'].type.sizeof) # size is itself an uintptr + if type_size > uintptr_size: + dynamic_gdb_type = dynamic_gdb_type.pointer() + return dynamic_gdb_type +def iface_dtype_name(obj): + "Decode type name of the data field of an eface or iface struct." + + if is_iface(obj): + go_type_ptr = obj['tab']['_type'] + elif is_eface(obj): + go_type_ptr = obj['_type'] + else: + return + + ct = gdb.lookup_type("struct runtime.commonType").pointer() + dynamic_go_type = go_type_ptr['ptr'].cast(ct).dereference() + return dynamic_go_type['string'].dereference()['str'].string() + class IfacePrinter: """Pretty print interface values @@ -224,6 +243,10 @@ class IfacePrinter: dtype = iface_dtype(self.val) except: return "" + + if not dtype: # trouble looking up, print something reasonable + return "(%s)%s" % (iface_dtype_name(self.val), self.val['data']) + try: return self.val['data'].cast(dtype).dereference() except: