TestFrames.py   [plain text]

"""
Use lldb Python SBFrame API to get the argument values of the call stacks.
And other SBFrame API tests.
"""

import os, time
import re
import unittest2
import lldb, lldbutil
from lldbtest import *

class FrameAPITestCase(TestBase):

    mydir = os.path.join("python_api", "frame")

    @unittest2.skipUnless(sys.platform.startswith("darwin"), "requires Darwin")
    @python_api_test
    @dsym_test
    def test_get_arg_vals_for_call_stack_with_dsym(self):
        """Exercise SBFrame.GetVariables() API to get argument vals."""
        self.buildDsym()
        self.do_get_arg_vals()

    @python_api_test
    @dwarf_test
    def test_get_arg_vals_for_call_stack_with_dwarf(self):
        """Exercise SBFrame.GetVariables() API to get argument vals."""
        self.buildDwarf()
        self.do_get_arg_vals()

    @python_api_test
    def test_frame_api_boundary_condition(self):
        """Exercise SBFrame APIs with boundary condition inputs."""
        self.buildDefault()
        self.frame_api_boundary_condition()

    @python_api_test
    def test_frame_api_IsEqual(self):
        """Exercise SBFrame API IsEqual."""
        self.buildDefault()
        self.frame_api_IsEqual()

    def do_get_arg_vals(self):
        """Get argument vals for the call stack when stopped on a breakpoint."""
        exe = os.path.join(os.getcwd(), "a.out")

        # Create a target by the debugger.
        target = self.dbg.CreateTarget(exe)
        self.assertTrue(target, VALID_TARGET)

        # Now create a breakpoint on main.c by name 'c'.
        breakpoint = target.BreakpointCreateByName('c', 'a.out')
        #print "breakpoint:", breakpoint
        self.assertTrue(breakpoint and
                        breakpoint.GetNumLocations() == 1,
                        VALID_BREAKPOINT)

        # Now launch the process, and do not stop at the entry point.
        process = target.LaunchSimple(None, None, os.getcwd())

        process = target.GetProcess()
        self.assertTrue(process.GetState() == lldb.eStateStopped,
                        PROCESS_STOPPED)

        # Keeps track of the number of times 'a' is called where it is within a
        # depth of 3 of the 'c' leaf function.
        callsOfA = 0

        import StringIO
        session = StringIO.StringIO()
        while process.GetState() == lldb.eStateStopped:
            thread = process.GetThreadAtIndex(0)
            # Inspect at most 3 frames.
            numFrames = min(3, thread.GetNumFrames())
            for i in range(numFrames):
                frame = thread.GetFrameAtIndex(i)
                if self.TraceOn():
                    print "frame:", frame

                name = frame.GetFunction().GetName()
                if name == 'a':
                    callsOfA = callsOfA + 1

                # We'll inspect only the arguments for the current frame:
                #
                # arguments     => True
                # locals        => False
                # statics       => False
                # in_scope_only => True
                valList = frame.GetVariables(True, False, False, True)
                argList = []
                for val in valList:
                    argList.append("(%s)%s=%s" % (val.GetTypeName(),
                                                  val.GetName(),
                                                  val.GetValue()))
                print >> session, "%s(%s)" % (name, ", ".join(argList))
                
                # Also check the generic pc & stack pointer.  We can't test their absolute values,
                # but they should be valid.  Uses get_GPRs() from the lldbutil module.
                gpr_reg_set = lldbutil.get_GPRs(frame)
                pc_value = gpr_reg_set.GetChildMemberWithName("pc")
                self.assertTrue (pc_value, "We should have a valid PC.")
                self.assertTrue (int(pc_value.GetValue(), 0) == frame.GetPC(), "PC gotten as a value should equal frame's GetPC")
                sp_value = gpr_reg_set.GetChildMemberWithName("sp")
                self.assertTrue (sp_value, "We should have a valid Stack Pointer.")
                self.assertTrue (int(sp_value.GetValue(), 0) == frame.GetSP(), "SP gotten as a value should equal frame's GetSP")

            print >> session, "---"
            process.Continue()

        # At this point, the inferior process should have exited.
        self.assertTrue(process.GetState() == lldb.eStateExited, PROCESS_EXITED)

        # Expect to find 'a' on the call stacks two times.
        self.assertTrue(callsOfA == 2,
                        "Expect to find 'a' on the call stacks two times")
        # By design, the 'a' call frame has the following arg vals:
        #     o a((int)val=1, (char)ch='A')
        #     o a((int)val=3, (char)ch='A')
        if self.TraceOn():
            print "Full stack traces when stopped on the breakpoint 'c':"
            print session.getvalue()
        self.expect(session.getvalue(), "Argugment values displayed correctly",
                    exe=False,
            substrs = ["a((int)val=1, (char)ch='A')",
                       "a((int)val=3, (char)ch='A')"])

    def frame_api_boundary_condition(self):
        exe = os.path.join(os.getcwd(), "a.out")

        # Create a target by the debugger.
        target = self.dbg.CreateTarget(exe)
        self.assertTrue(target, VALID_TARGET)

        # Now create a breakpoint on main.c by name 'c'.
        breakpoint = target.BreakpointCreateByName('c', 'a.out')
        #print "breakpoint:", breakpoint
        self.assertTrue(breakpoint and
                        breakpoint.GetNumLocations() == 1,
                        VALID_BREAKPOINT)

        # Now launch the process, and do not stop at the entry point.
        process = target.LaunchSimple(None, None, os.getcwd())

        process = target.GetProcess()
        self.assertTrue(process.GetState() == lldb.eStateStopped,
                        PROCESS_STOPPED)

        thread = process.GetThreadAtIndex(0)
        frame = thread.GetFrameAtIndex(0)
        if self.TraceOn():
            print "frame:", frame

        # Boundary condition testings.
        val1 = frame.FindVariable(None, True)
        val2 = frame.FindVariable(None, False)
        val3 = frame.FindValue(None, lldb.eValueTypeVariableGlobal)
        if self.TraceOn():
            print "val1:", val1
            print "val2:", val2

        frame.EvaluateExpression(None)

    def frame_api_IsEqual(self):
        """Exercise SBFrame API IsEqual."""
        exe = os.path.join(os.getcwd(), "a.out")

        # Create a target by the debugger.
        target = self.dbg.CreateTarget(exe)
        self.assertTrue(target, VALID_TARGET)

        # Now create a breakpoint on main.c by name 'c'.
        breakpoint = target.BreakpointCreateByName('c', 'a.out')
        #print "breakpoint:", breakpoint
        self.assertTrue(breakpoint and
                        breakpoint.GetNumLocations() == 1,
                        VALID_BREAKPOINT)

        # Now launch the process, and do not stop at the entry point.
        process = target.LaunchSimple(None, None, os.getcwd())

        process = target.GetProcess()
        self.assertTrue(process.GetState() == lldb.eStateStopped,
                        PROCESS_STOPPED)

        thread = process.GetThreadAtIndex(0)
        self.assertTrue(thread)

        frameEntered = thread.GetFrameAtIndex(0)
        if self.TraceOn():
            print frameEntered
            lldbutil.print_stacktrace(thread)
        self.assertTrue(frameEntered)

        # Doing two step overs while still inside c().
        thread.StepOver()
        thread.StepOver()
        self.assertTrue(thread)
        frameNow = thread.GetFrameAtIndex(0)
        if self.TraceOn():
            print frameNow
            lldbutil.print_stacktrace(thread)
        self.assertTrue(frameNow)

        # The latest two frames are considered equal.
        self.assertTrue(frameEntered.IsEqual(frameNow))

        # Now let's step out of frame c().
        thread.StepOutOfFrame(frameNow)
        frameOutOfC = thread.GetFrameAtIndex(0)
        if self.TraceOn():
            print frameOutOfC
            lldbutil.print_stacktrace(thread)
        self.assertTrue(frameOutOfC)

        # The latest two frames should not be equal.
        self.assertFalse(frameOutOfC.IsEqual(frameNow))


if __name__ == '__main__':
    import atexit
    lldb.SBDebugger.Initialize()
    atexit.register(lambda: lldb.SBDebugger.Terminate())
    unittest2.main()