[LLDB][MIPS] A small fix in GetBreakableLoadAddress() for MIPS

    
    SUMMARY:
    Get the load address for the address given by symbol and function.
    Earlier, this was done for function only, this patch does it for symbol too.
    This patch also adds TestAvoidBreakpointInDelaySlot.py to test this change.
    
    Reviewers: clayborg
    Subscribers: labath, zturner, mohit.bhakkad, sagar, jaydeep, lldb-commits
    Differential Revision: http://reviews.llvm.org/D16049

llvm-svn: 258919

3 files changed, 109 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/Makefile b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/Makefile
new file mode 100644
index 00000000000..77aa24afc0f
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/Makefile
@@ -0,0 +1,6 @@
+LEVEL = ../../../make
+
+C_SOURCES := main.c
+
+include $(LEVEL)/Makefile.rules
+
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/TestAvoidBreakpointInDelaySlot.py b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/TestAvoidBreakpointInDelaySlot.py
new file mode 100644
index 00000000000..bab56e21040
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/TestAvoidBreakpointInDelaySlot.py
@@ -0,0 +1,82 @@
+"""
+Test specific to MIPS 
+"""
+
+import os, time
+import re
+import unittest2
+import lldb
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbtest import *
+
+class AvoidBreakpointInDelaySlotAPITestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @skipUnlessArch(archs=re.compile('mips*'))
+    def test(self):
+        self.build()
+        exe = os.path.join(os.getcwd(), "a.out")
+        self.expect("file " + exe,
+                    patterns = [ "Current executable set to .*a.out.*" ])
+        
+        # Create a target by the debugger.
+        target = self.dbg.CreateTarget(exe)
+        self.assertTrue(target, VALID_TARGET)
+
+        breakpoint = target.BreakpointCreateByName('main', 'a.out')
+        self.assertTrue(breakpoint and
+                        breakpoint.GetNumLocations() == 1,
+                        VALID_BREAKPOINT)
+
+        # Now launch the process, and do not stop at entry point.
+        process = target.LaunchSimple (None, None, self.get_process_working_directory())
+        self.assertTrue(process, PROCESS_IS_VALID)
+
+        list = target.FindFunctions('foo', lldb.eFunctionNameTypeAuto)
+        self.assertTrue(list.GetSize() == 1)
+        sc = list.GetContextAtIndex(0)
+        self.assertTrue(sc.GetSymbol().GetName() == "foo")
+        function = sc.GetFunction()
+        self.assertTrue(function)
+        self.function(function, target)
+
+    def function (self, function, target):
+        """Iterate over instructions in function and place a breakpoint on delay slot instruction"""
+        # Get the list of all instructions in the function
+        insts = function.GetInstructions(target)
+        print insts
+        i = 0
+        for inst in insts:
+            if (inst.HasDelaySlot()):
+                # Remember the address of branch instruction.
+                branchinstaddress = inst.GetAddress().GetLoadAddress(target)
+
+                # Get next instruction i.e delay slot instruction.
+                delayinst = insts.GetInstructionAtIndex(i+1)
+                delayinstaddr = delayinst.GetAddress().GetLoadAddress(target)
+
+                # Set breakpoint on delay slot instruction
+                breakpoint = target.BreakpointCreateByAddress(delayinstaddr)
+
+                # Verify the breakpoint.
+                self.assertTrue(breakpoint and
+                                breakpoint.GetNumLocations() == 1,
+                                VALID_BREAKPOINT)
+                # Get the location from breakpoint
+                location = breakpoint.GetLocationAtIndex(0)
+
+                # Get the address where breakpoint is actually set.
+                bpaddr = location.GetLoadAddress()
+		
+                # Breakpoint address should be adjusted to the address of branch instruction.
+                self.assertTrue(branchinstaddress ==  bpaddr)
+                i += 1
+            else:
+                i += 1
+
+if __name__ == '__main__':
+    import atexit
+    lldb.SBDebugger.Initialize()
+    atexit.register(lambda: lldb.SBDebugger.Terminate())
+    unittest2.main()
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/main.c b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/main.c
new file mode 100644
index 00000000000..bc3eceea769
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/breakpoint/breakpoint_in_delayslot/main.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+
+foo (int a, int b)
+{
+    int c;
+    if (a<=b)
+        c=b-a;
+    else
+        c=b+a;
+    return c;
+}
+
+int main()
+{
+    int a=7, b=8, c;
+    
+    c = foo(a, b);
+
+return 0;
+}
+