[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

lldb/include/lldb/API/SBInstruction.h

@@ -60,6 +60,9 @@ public:
     bool
     DoesBranch ();
 
+    bool
+    HasDelaySlot ();
+
     void
     Print (FILE *out);
 

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
+

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()

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;
+}
+

lldb/packages/Python/lldbsuite/test/lldbtest.py

@@ -636,6 +636,14 @@ def check_list_or_lambda(list_or_lambda, value):
     else:
         return list_or_lambda is None or value is None or list_or_lambda == value
 
+def matchArchitectures(archs, actual_arch):
+    retype = type(re.compile('hello, world'))
+    list_passes = isinstance(archs, list) and actual_arch in archs
+    basestring_passes = isinstance(archs, basestring) and actual_arch == archs
+    regex_passes = isinstance(archs, retype) and re.match(archs, actual_arch)
+
+    return (list_passes or basestring_passes or regex_passes)
+
 # provide a function to xfail on defined oslist, compiler version, and archs
 # if none is specified for any argument, that argument won't be checked and thus means for all
 # for example,
@@ -1029,7 +1037,7 @@ def skipUnlessHostPlatform(oslist):
     return unittest2.skipUnless(getHostPlatform() in oslist,
                                 "requires on of %s" % (", ".join(oslist)))
 
-def skipUnlessArch(archlist):
+def skipUnlessArch(archs):
     """Decorate the item to skip tests unless running on one of the listed architectures."""
     def myImpl(func):
         if isinstance(func, type) and issubclass(func, unittest2.TestCase):
@@ -1038,9 +1046,8 @@ def skipUnlessArch(archlist):
         @wraps(func)
         def wrapper(*args, **kwargs):
             self = args[0]
-            if self.getArchitecture() not in archlist:
+            if not matchArchitectures(archs, self.getArchitecture()):
-                self.skipTest("skipping for architecture %s (requires one of %s)" % 
+                self.skipTest("skipping for architecture %s" % (self.getArchitecture())) 
-                    (self.getArchitecture(), ", ".join(archlist)))
             else:
                 func(*args, **kwargs)
         return wrapper

lldb/scripts/interface/SBInstruction.i

@@ -51,6 +51,9 @@ public:
     bool
     DoesBranch ();
 
+    bool
+    HasDelaySlot ();
+
     void
     Print (FILE *out);
 

lldb/source/API/SBInstruction.cpp

@@ -160,6 +160,14 @@ SBInstruction::DoesBranch ()
     return false;
 }
 
+bool
+SBInstruction::HasDelaySlot ()
+{
+    if (m_opaque_sp)
+        return m_opaque_sp->HasDelaySlot ();
+    return false;
+}
+
 void
 SBInstruction::SetOpaque (const lldb::InstructionSP &inst_sp)
 {

lldb/source/Target/Target.cpp

@@ -2442,18 +2442,18 @@ Target::GetBreakableLoadAddress (lldb::addr_t addr)
             SymbolContext sc;
             uint32_t resolve_scope = eSymbolContextFunction | eSymbolContextSymbol;
             temp_addr_module_sp->ResolveSymbolContextForAddress(resolved_addr, resolve_scope, sc);
+            Address sym_addr;
             if (sc.function)
-            {
+                sym_addr = sc.function->GetAddressRange().GetBaseAddress();
-                function_start = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress(this);
-                if (function_start == LLDB_INVALID_ADDRESS)
-                    function_start = sc.function->GetAddressRange().GetBaseAddress().GetFileAddress();
-            }
             else if (sc.symbol)
-            {
+                sym_addr = sc.symbol->GetAddress();
-                Address sym_addr = sc.symbol->GetAddress();
+
+            function_start = sym_addr.GetLoadAddress(this);
+            if (function_start == LLDB_INVALID_ADDRESS)
                 function_start = sym_addr.GetFileAddress();
-            }
+
-            current_offset = addr - function_start;
+            if (function_start)
+                current_offset = addr - function_start;
         }
 
         // If breakpoint address is start of function then we dont have to do anything.