xref: /llvm-project/lldb/test/API/commands/expression/weak_symbols/TestWeakSymbols.py (revision 2238dcc39358353cac21df75c3c3286ab20b8f53) 
1"""
2Test that we can compile expressions referring to
3absent weak symbols from a dylib.
4"""
5
6
7import os
8import lldb
9from lldbsuite.test.decorators import *
10import lldbsuite.test.lldbutil as lldbutil
11from lldbsuite.test.lldbtest import *
12
13
14class TestWeakSymbolsInExpressions(TestBase):
15    NO_DEBUG_INFO_TESTCASE = True
16
17    @skipUnlessDarwin
18    @skipIf(compiler="clang", compiler_version=["<", "7.0"])
19    def test_weak_symbol_in_expr(self):
20        """Tests that we can refer to weak symbols in expressions."""
21        self.build()
22        self.main_source_file = lldb.SBFileSpec("main.c")
23        self.do_test()
24
25    def run_weak_var_check(self, weak_varname, present):
26        # The expression will modify present_weak_int to signify which branch
27        # was taken.  Set it to so we don't get confused by a previous run.
28        value = self.target.FindFirstGlobalVariable("present_weak_int")
29        value.SetValueFromCString("0")
30        if present:
31            correct_value = 10
32        else:
33            correct_value = 20
34
35        # Note, I'm adding the "; 10" at the end of the expression to work around
36        # the bug that expressions with no result currently return False for Success()...
37        expr = (
38            "if (&"
39            + weak_varname
40            + " != NULL) { present_weak_int = 10; } else { present_weak_int = 20;}; 10"
41        )
42        result = self.frame.EvaluateExpression(expr)
43        self.assertSuccess(result.GetError(), "absent_weak_int expr failed")
44        self.assertEqual(
45            value.GetValueAsSigned(),
46            correct_value,
47            "Didn't change present_weak_int correctly.",
48        )
49
50    def do_test(self):
51        hidden_dir = os.path.join(self.getBuildDir(), "hidden")
52        hidden_dylib = os.path.join(hidden_dir, "libdylib.dylib")
53
54        launch_info = lldb.SBLaunchInfo(None)
55        launch_info.SetWorkingDirectory(self.getBuildDir())
56        launch_info.SetLaunchFlags(lldb.eLaunchFlagInheritTCCFromParent)
57
58        (self.target, _, thread, _) = lldbutil.run_to_source_breakpoint(
59            self,
60            "Set a breakpoint here",
61            self.main_source_file,
62            launch_info=launch_info,
63            extra_images=[hidden_dylib],
64        )
65        # First we have to import the Dylib module so we get the type info
66        # for the weak symbol.  We need to add the source dir to the module
67        # search paths, and then run @import to introduce it into the expression
68        # context:
69        self.dbg.HandleCommand(
70            "settings set target.clang-module-search-paths " + self.getSourceDir()
71        )
72
73        self.frame = thread.frames[0]
74        self.assertTrue(self.frame.IsValid(), "Got a good frame")
75        options = lldb.SBExpressionOptions()
76        options.SetLanguage(lldb.eLanguageTypeObjC)
77        result = self.frame.EvaluateExpression("@import Dylib", options)
78
79        # Now run an expression that references an absent weak symbol:
80        self.run_weak_var_check("absent_weak_int", False)
81        self.run_weak_var_check("absent_weak_function", False)
82
83        # Make sure we can do the same thing with present weak symbols
84        self.run_weak_var_check("present_weak_int", True)
85        self.run_weak_var_check("present_weak_function", True)
86