llvm-project/lldb/test/API/functionalities/load_lazy/TestLoadUsingLazyBind.py
Vedant Kumar 4bd2bfb6ec [lldb/PlatformPOSIX] Change LoadImage default to RTLD_LAZY (reapply)
In general, it seems like the debugger should allow programs to load & run with
libraries as far as possible, instead of defaulting to being super-picky about
unavailable symbols.

This is critical on macOS/Darwin, as libswiftCore.dylib may 1) export a version
symbol using @available markup and then 2) expect that other exported APIs are
only dynamically used once the version symbol is checked. We can't open a
version of the library built with a bleeding-edge SDK on an older OS without
RTLD_LAXY (or pervasive/expensive @available markup added to dyld APIs).

This was previously committed as cb8c1ee269da and reverted due to
unknown failures on the Linux bots. This version adds additional asserts
to check that the shared objects are where we expect them & that calling
f1() from libt1 produces the expected value. The Linux failure is
tracked by https://bugs.llvm.org/show_bug.cgi?id=49656.

See: https://lists.llvm.org/pipermail/lldb-dev/2021-March/016796.html

Differential Revision: https://reviews.llvm.org/D98879
2021-03-19 16:06:00 -07:00

66 lines
2.0 KiB
Python

"""
Test that SBProcess.LoadImageUsingPaths uses RTLD_LAZY
"""
import os
import shutil
import lldb
from lldbsuite.test.decorators import *
from lldbsuite.test.lldbtest import *
from lldbsuite.test import lldbutil
class LoadUsingLazyBind(TestBase):
mydir = TestBase.compute_mydir(__file__)
NO_DEBUG_INFO_TESTCASE = True
@skipIfRemote
@skipIfWindows # The Windows platform doesn't implement DoLoadImage.
# Failing for unknown reasons on Linux, see
# https://bugs.llvm.org/show_bug.cgi?id=49656.
@skipUnlessDarwin
def test_load_using_lazy_bind(self):
"""Test that we load using RTLD_LAZY"""
self.build()
wd = os.path.realpath(self.getBuildDir())
ext = '.so'
if self.platformIsDarwin():
ext = '.dylib'
def make_lib_path(name):
libpath = os.path.join(wd, name + ext)
self.assertTrue(os.path.exists(libpath))
return libpath
libt1 = make_lib_path('libt1')
libt2_0 = make_lib_path('libt2_0')
libt2_1 = make_lib_path('libt2_1')
# Overwrite t2_0 with t2_1 to delete the definition of `use`.
shutil.copy(libt2_1, libt2_0)
# Launch a process and break
(target, process, thread, _) = lldbutil.run_to_source_breakpoint(self,
"break here",
lldb.SBFileSpec("main.cpp"))
# Load libt1; should fail unless we use RTLD_LAZY
error = lldb.SBError()
lib_spec = lldb.SBFileSpec('libt1' + ext)
paths = lldb.SBStringList()
paths.AppendString(wd)
out_spec = lldb.SBFileSpec()
token = process.LoadImageUsingPaths(lib_spec, paths, out_spec, error)
self.assertNotEqual(token, lldb.LLDB_INVALID_IMAGE_TOKEN, "Got a valid token")
# Calling `f1()` should return 5.
frame = thread.GetFrameAtIndex(0)
val = frame.EvaluateExpression("f1()")
self.assertTrue(val.IsValid())
self.assertEquals(val.GetValueAsSigned(-1), 5)