python-gdb.py: enhance py-bt command
* Add py-bt-full command
* py-bt now gives an output similar to a regular Python traceback
* py-bt indicates:
- if the garbage collector is running
- if the thread is waiting for the GIL
- detect PyCFunction_Call to get the name of the builtin function
diff --git a/Lib/test/test_gdb.py b/Lib/test/test_gdb.py
index 0b8c0c8..fc65c2a 100644
--- a/Lib/test/test_gdb.py
+++ b/Lib/test/test_gdb.py
@@ -13,6 +13,12 @@
from test import test_support
from test.test_support import run_unittest, findfile
+# Is this Python configured to support threads?
+try:
+ import thread
+except ImportError:
+ thread = None
+
def get_gdb_version():
try:
proc = subprocess.Popen(["gdb", "-nx", "--version"],
@@ -728,20 +734,133 @@
class PyBtTests(DebuggerTests):
@unittest.skipIf(python_is_optimized(),
"Python was compiled with optimizations")
- def test_basic_command(self):
+ def test_bt(self):
'Verify that the "py-bt" command works'
bt = self.get_stack_trace(script=self.get_sample_script(),
cmds_after_breakpoint=['py-bt'])
self.assertMultilineMatches(bt,
r'''^.*
-#[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\)
+Traceback \(most recent call first\):
+ File ".*gdb_sample.py", line 10, in baz
+ print\(42\)
+ File ".*gdb_sample.py", line 7, in bar
baz\(a, b, c\)
-#[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \(a=1, b=2, c=3\)
+ File ".*gdb_sample.py", line 4, in foo
bar\(a, b, c\)
-#[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \(\)
+ File ".*gdb_sample.py", line 12, in <module>
foo\(1, 2, 3\)
''')
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
+ def test_bt_full(self):
+ 'Verify that the "py-bt-full" command works'
+ bt = self.get_stack_trace(script=self.get_sample_script(),
+ cmds_after_breakpoint=['py-bt-full'])
+ self.assertMultilineMatches(bt,
+ r'''^.*
+#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\)
+ baz\(a, b, c\)
+#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \(a=1, b=2, c=3\)
+ bar\(a, b, c\)
+#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \(\)
+ foo\(1, 2, 3\)
+''')
+
+ @unittest.skipUnless(thread,
+ "Python was compiled without thread support")
+ def test_threads(self):
+ 'Verify that "py-bt" indicates threads that are waiting for the GIL'
+ cmd = '''
+from threading import Thread
+
+class TestThread(Thread):
+ # These threads would run forever, but we'll interrupt things with the
+ # debugger
+ def run(self):
+ i = 0
+ while 1:
+ i += 1
+
+t = {}
+for i in range(4):
+ t[i] = TestThread()
+ t[i].start()
+
+# Trigger a breakpoint on the main thread
+print 42
+
+'''
+ # Verify with "py-bt":
+ gdb_output = self.get_stack_trace(cmd,
+ cmds_after_breakpoint=['thread apply all py-bt'])
+ self.assertIn('Waiting for the GIL', gdb_output)
+
+ # Verify with "py-bt-full":
+ gdb_output = self.get_stack_trace(cmd,
+ cmds_after_breakpoint=['thread apply all py-bt-full'])
+ self.assertIn('Waiting for the GIL', gdb_output)
+
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
+ # Some older versions of gdb will fail with
+ # "Cannot find new threads: generic error"
+ # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround
+ @unittest.skipUnless(thread,
+ "Python was compiled without thread support")
+ def test_gc(self):
+ 'Verify that "py-bt" indicates if a thread is garbage-collecting'
+ cmd = ('from gc import collect\n'
+ 'print 42\n'
+ 'def foo():\n'
+ ' collect()\n'
+ 'def bar():\n'
+ ' foo()\n'
+ 'bar()\n')
+ # Verify with "py-bt":
+ gdb_output = self.get_stack_trace(cmd,
+ cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt'],
+ )
+ self.assertIn('Garbage-collecting', gdb_output)
+
+ # Verify with "py-bt-full":
+ gdb_output = self.get_stack_trace(cmd,
+ cmds_after_breakpoint=['break update_refs', 'continue', 'py-bt-full'],
+ )
+ self.assertIn('Garbage-collecting', gdb_output)
+
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
+ # Some older versions of gdb will fail with
+ # "Cannot find new threads: generic error"
+ # unless we add LD_PRELOAD=PATH-TO-libpthread.so.1 as a workaround
+ @unittest.skipUnless(thread,
+ "Python was compiled without thread support")
+ def test_pycfunction(self):
+ 'Verify that "py-bt" displays invocations of PyCFunction instances'
+ # Tested function must not be defined with METH_NOARGS or METH_O,
+ # otherwise call_function() doesn't call PyCFunction_Call()
+ cmd = ('from time import gmtime\n'
+ 'def foo():\n'
+ ' gmtime(1)\n'
+ 'def bar():\n'
+ ' foo()\n'
+ 'bar()\n')
+ # Verify with "py-bt":
+ gdb_output = self.get_stack_trace(cmd,
+ breakpoint='time_gmtime',
+ cmds_after_breakpoint=['bt', 'py-bt'],
+ )
+ self.assertIn('<built-in function gmtime', gdb_output)
+
+ # Verify with "py-bt-full":
+ gdb_output = self.get_stack_trace(cmd,
+ breakpoint='time_gmtime',
+ cmds_after_breakpoint=['py-bt-full'],
+ )
+ self.assertIn('#0 <built-in function gmtime', gdb_output)
+
+
class PyPrintTests(DebuggerTests):
@unittest.skipIf(python_is_optimized(),
"Python was compiled with optimizations")