[Tarantool-patches] [PATCH v2 luajit 3/3] gdb: enhance the extension loading
Igor Munkin
imun at tarantool.org
Wed Feb 5 19:22:29 MSK 2020
Definition of LJ_64, LJ_GC64 and LJ_FR2 constants in script requires
LuaJIT internal enum values to be presented in the executable. Otherwise
the extension loading fails. The changes handles exception for the
following scenarios:
* luajit-gdb.py is loaded for an arbitrary executable, e.g. /bin/echo
* luajit-gdb.py is loaded for a luajit executable (or the one linked
against libluajit) but debug info is not found
Signed-off-by: Igor Munkin <imun at tarantool.org>
---
src/luajit-gdb.py | 102 ++++++++++++++++++++--------------------------
1 file changed, 45 insertions(+), 57 deletions(-)
diff --git a/src/luajit-gdb.py b/src/luajit-gdb.py
index 90df101..bc37674 100644
--- a/src/luajit-gdb.py
+++ b/src/luajit-gdb.py
@@ -1,3 +1,6 @@
+# GDB extension for LuaJIT post-mortem analysis.
+# To use, just put 'source <path-to-repo>/src/luajit-gdb.py' in gdb.
+
import re
import gdb
import sys
@@ -151,11 +154,9 @@ def frame_prev(framelink):
# Const {{{
-LJ_64 = str(gdb.parse_and_eval('IRT_PTR')) == 'IRT_P64'
-
-LJ_GC64 = str(gdb.parse_and_eval('IRT_PGC')) == 'IRT_P64'
-
-LJ_FR2 = LJ_GC64
+LJ_64 = None
+LJ_GC64 = None
+LJ_FR2 = None
LJ_GCVMASK = ((1 << 47) - 1)
@@ -460,7 +461,14 @@ def dump_gc(g):
return '\n'.join(map(lambda s: '\t' + s, stats))
-class LJDumpArch(gdb.Command):
+
+class LJBase(gdb.Command):
+
+ def __init__(self, name):
+ super(__class__, self).__init__(name, gdb.COMMAND_DATA)
+ gdb.write('{} command initialized\n'.format(name))
+
+class LJDumpArch(LJBase):
'''
lj-arch
@@ -469,20 +477,13 @@ compile-time flags. These values define the sizes of host and GC
pointers respectively.
'''
- def __init__(self):
- super(LJDumpArch, self).__init__(
- 'lj-arch', gdb.COMMAND_DATA
- )
-
def invoke(self, arg, from_tty):
gdb.write('LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}\n'.format(
LJ_64 = LJ_64,
LJ_GC64 = LJ_GC64
))
-LJDumpArch()
-
-class LJDumpTValue(gdb.Command):
+class LJDumpTValue(LJBase):
'''
lj-tv <TValue *>
@@ -511,18 +512,11 @@ Whether the type of the given address differs from the listed above, then
error message occurs.
'''
- def __init__(self):
- super(LJDumpTValue, self).__init__(
- 'lj-tv', gdb.COMMAND_DATA
- )
-
def invoke(self, arg, from_tty):
tv = cast('TValue *', parse_arg(arg))
gdb.write('{}\n'.format(dump_tvalue(tv)))
-LJDumpTValue()
-
-class LJDumpString(gdb.Command):
+class LJDumpString(LJBase):
'''
lj-str <GCstr *>
@@ -533,11 +527,6 @@ the payload, size in bytes and hash.
is replaced with the corresponding error when decoding fails.
'''
- def __init__(self):
- super(LJDumpString, self).__init__(
- 'lj-str', gdb.COMMAND_DATA
- )
-
def invoke(self, arg, from_tty):
string = cast('GCstr *', parse_arg(arg))
gdb.write("String: {body} [{len} bytes] with hash {hash}\n".format(
@@ -546,10 +535,7 @@ is replaced with the corresponding error when decoding fails.
len = string['len'],
))
-
-LJDumpString()
-
-class LJDumpTable(gdb.Command):
+class LJDumpTable(LJBase):
'''
lj-tab <GCtab *>
@@ -561,10 +547,6 @@ The command recieves a GCtab adress and dumps the table contents:
<hnode ptr>: { <tv> } => { <tv> }; next = <next hnode ptr>
'''
- def __init__(self):
- super(LJDumpTable, self).__init__(
- 'lj-tab', gdb.COMMAND_DATA)
-
def invoke(self, arg, from_tty):
t = cast('GCtab *', parse_arg(arg))
array = mref('TValue *', t['array'])
@@ -598,9 +580,7 @@ The command recieves a GCtab adress and dumps the table contents:
n = mref('struct Node *', node['next'])
))
-LJDumpTable()
-
-class LJDumpStack(gdb.Command):
+class LJDumpStack(LJBase):
'''
lj-stack [<lua_State *>]
@@ -633,16 +613,10 @@ coroutine guest stack:
If L is ommited the main coroutine is used.
'''
- def __init__(self):
- super(LJDumpStack, self).__init__(
- 'lj-stack', gdb.COMMAND_DATA)
-
def invoke(self, arg, from_tty):
gdb.write('{}\n'.format(dump_stack(L(parse_arg(arg)))))
-LJDumpStack()
-
-class LJState(gdb.Command):
+class LJState(LJBase):
'''
lj-state
The command requires no args and dumps current VM and GC states
@@ -651,10 +625,6 @@ The command requires no args and dumps current VM and GC states
* JIT state: <IDLE|ACTIVE|RECORD|START|END|ASM|ERR>
'''
- def __init__(self):
- super(LJState, self).__init__(
- 'lj-state', gdb.COMMAND_DATA)
-
def invoke(self, arg, from_tty):
g = G(L(None))
gdb.write('{}\n'.format('\n'.join(
@@ -665,9 +635,7 @@ The command requires no args and dumps current VM and GC states
}.items())
)))
-LJState()
-
-class LJGC(gdb.Command):
+class LJGC(LJBase):
'''
lj-gc
@@ -685,10 +653,6 @@ The command requires no args and dumps current GC stats:
* weak: <number of weak tables (to be cleared)>
'''
- def __init__(self):
- super(LJGC, self).__init__(
- 'lj-gc', gdb.COMMAND_DATA)
-
def invoke(self, arg, from_tty):
g = G(L(None))
gdb.write('GC stats: {state}\n{stats}\n'.format(
@@ -696,4 +660,28 @@ The command requires no args and dumps current GC stats:
stats = dump_gc(g)
))
-LJGC()
+def load(commands):
+ global LJ_64, LJ_GC64, LJ_FR2
+
+ try:
+ LJ_64 = str(gdb.parse_and_eval('IRT_PTR')) == 'IRT_P64'
+ LJ_FR2 = LJ_GC64 = str(gdb.parse_and_eval('IRT_PGC')) == 'IRT_P64'
+ except:
+ gdb.write('luajit-gdb.py failed to load: '
+ 'no debugging symbols found for libluajit\n')
+ return
+
+ for name, command in commands.items():
+ command(name)
+
+ gdb.write('luajit-gdb.py is successfully loaded\n')
+
+load({
+ 'lj-arch': LJDumpArch,
+ 'lj-tv': LJDumpTValue,
+ 'lj-str': LJDumpString,
+ 'lj-tab': LJDumpTable,
+ 'lj-stack': LJDumpStack,
+ 'lj-state': LJState,
+ 'lj-gc': LJGC,
+})
--
2.24.0
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