xref: /llvm-project/lldb/test/API/functionalities/data-formatter/synthcapping/TestSyntheticCapping.py (revision 763b96c86d81d51d0db430791a61fd1e8a406bce) 
1"""
2Check for an issue where capping does not work because the Target pointer appears to be changing behind our backs
3"""
4
5
6import lldb
7from lldbsuite.test.decorators import *
8from lldbsuite.test.lldbtest import *
9from lldbsuite.test import lldbutil
10
11
12class SyntheticCappingTestCase(TestBase):
13    def setUp(self):
14        # Call super's setUp().
15        TestBase.setUp(self)
16        # Find the line number to break at.
17        self.line = line_number("main.cpp", "// Set break point at this line.")
18
19    def test_with_run_command(self):
20        """Check for an issue where capping does not work because the Target pointer appears to be changing behind our backs."""
21        self.build()
22        self.runCmd("file " + self.getBuildArtifact("a.out"), CURRENT_EXECUTABLE_SET)
23
24        lldbutil.run_break_set_by_file_and_line(
25            self, "main.cpp", self.line, num_expected_locations=1, loc_exact=True
26        )
27
28        self.runCmd("run", RUN_SUCCEEDED)
29
30        process = self.dbg.GetSelectedTarget().GetProcess()
31
32        # The stop reason of the thread should be breakpoint.
33        self.expect(
34            "thread list",
35            STOPPED_DUE_TO_BREAKPOINT,
36            substrs=["stopped", "stop reason = breakpoint"],
37        )
38
39        # This is the function to remove the custom formats in order to have a
40        # clean slate for the next test case.
41        def cleanup():
42            self.runCmd("type format clear", check=False)
43            self.runCmd("type summary clear", check=False)
44            self.runCmd("type filter clear", check=False)
45            self.runCmd("type synth clear", check=False)
46            self.runCmd("settings set target.max-children-count 256", check=False)
47
48        # Execute the cleanup function during test case tear down.
49        self.addTearDownHook(cleanup)
50
51        # set up the synthetic children provider
52        self.runCmd("script from fooSynthProvider import *")
53        self.runCmd("type synth add -l fooSynthProvider foo")
54
55        # note that the value of fake_a depends on target byte order
56        if process.GetByteOrder() == lldb.eByteOrderLittle:
57            fake_a_val = 0x02000000
58        else:
59            fake_a_val = 0x00000100
60
61        # check that the synthetic children work, so we know we are doing the
62        # right thing
63        self.expect(
64            "frame variable f00_1",
65            substrs=[
66                "a = 1",
67                "fake_a = %d" % fake_a_val,
68                "r = 34",
69            ],
70        )
71        # num_children() should be called with at most max_num_children=257
72        # (target.max-children-count + 1)
73        self.expect(
74            "script fooSynthProvider.reset_max_num_children_max()", substrs=["257"]
75        )
76
77        # check that capping works
78        self.runCmd("settings set target.max-children-count 2", check=False)
79
80        self.expect(
81            "frame variable f00_1",
82            substrs=[
83                "a = 1",
84                "fake_a = %d" % fake_a_val,
85                "...",
86            ],
87        )
88        self.expect(
89            "script fooSynthProvider.reset_max_num_children_max()", substrs=["3"]
90        )
91
92        self.expect("frame variable f00_1", matching=False, substrs=["r = 34"])
93
94        self.runCmd("settings set target.max-children-count 256", check=False)
95
96        self.expect("frame variable f00_1", matching=True, substrs=["r = 34"])
97        self.expect(
98            "script fooSynthProvider.reset_max_num_children_max()", substrs=["257"]
99        )
100