Fixed a problem in IRForTarget where we would not

delete a constant after we replaced it with a
dynamically-computed value.  Also ensured that we
replace all users of the constant if there are
multiple ones.  Added a testcase.

<rdar://problem/14379043>

llvm-svn: 186363

lldb/source/Expression/IRForTarget.cpp

@@ -2210,7 +2210,8 @@ IRForTarget::UnfoldConstant(Constant *old_constant,
                                                    llvm::cast<Instruction>(entry_instruction_finder.GetValue(function)));
                         });
                         
-                        return UnfoldConstant(constant_expr, bit_cast_maker, entry_instruction_finder);
+                        if (!UnfoldConstant(constant_expr, bit_cast_maker, entry_instruction_finder))
+                            return false;
                     }
                     break;
                 case Instruction::GetElementPtr:
@@ -2247,7 +2248,8 @@ IRForTarget::UnfoldConstant(Constant *old_constant,
                             return GetElementPtrInst::Create(ptr, indices, "", llvm::cast<Instruction>(entry_instruction_finder.GetValue(function)));
                         });
                         
-                        return UnfoldConstant(constant_expr, get_element_pointer_maker, entry_instruction_finder);
+                        if (!UnfoldConstant(constant_expr, get_element_pointer_maker, entry_instruction_finder))
+                            return false;
                     }
                     break;
                 }
@@ -2274,6 +2276,11 @@ IRForTarget::UnfoldConstant(Constant *old_constant,
         }
     }
     
+    if (!isa<GlobalValue>(old_constant))
+    {
+        old_constant->destroyConstant();
+    }
+    
     return true;
 }
 

lldb/test/lang/objc/objc-struct-return/Makefile

@@ -0,0 +1,6 @@
+LEVEL = ../../../make
+
+OBJC_SOURCES := test.m
+LDFLAGS = $(CFLAGS) -lobjc -framework Foundation
+
+include $(LEVEL)/Makefile.rules

lldb/test/lang/objc/objc-struct-return/TestObjCStructReturn.py

@@ -0,0 +1,69 @@
+"""Test calling functions in class methods."""
+
+import os, time
+import unittest2
+import lldb
+import lldbutil
+from lldbtest import *
+
+class TestObjCClassMethod(TestBase):
+
+    mydir = os.path.join("lang", "objc", "objc-class-method")
+
+    @unittest2.skipUnless(sys.platform.startswith("darwin"), "requires Darwin")
+    @python_api_test
+    @dsym_test
+    def test_with_dsym_and_python_api(self):
+        """Test calling functions in class methods."""
+        self.buildDsym()
+        self.objc_class_method()
+
+    @unittest2.skipUnless(sys.platform.startswith("darwin"), "requires Darwin")
+    @python_api_test
+    @dwarf_test
+    def test_with_dwarf_and_python_api(self):
+        """Test calling functions in class methods."""
+        self.buildDwarf()
+        self.objc_class_method()
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+        # Find the line numbers to break inside main().
+        self.main_source = "class.m"
+        self.break_line = line_number(self.main_source, '// Set breakpoint here.')
+
+    def objc_class_method(self):
+        """Test calling class methods."""
+        exe = os.path.join(os.getcwd(), "a.out")
+
+        target = self.dbg.CreateTarget(exe)
+        self.assertTrue(target, VALID_TARGET)
+
+        bpt = target.BreakpointCreateByLocation(self.main_source, self.break_line)
+        self.assertTrue(bpt, VALID_BREAKPOINT)
+
+        # Now launch the process, and do not stop at entry point.
+        process = target.LaunchSimple (None, None, os.getcwd())
+
+        self.assertTrue(process, PROCESS_IS_VALID)
+
+        # The stop reason of the thread should be breakpoint.
+        thread_list = lldbutil.get_threads_stopped_at_breakpoint (process, bpt)
+
+        # Make sure we stopped at the first breakpoint.
+        self.assertTrue (len(thread_list) != 0, "No thread stopped at our breakpoint.")
+        self.assertTrue (len(thread_list) == 1, "More than one thread stopped at our breakpoint.")
+            
+        frame = thread_list[0].GetFrameAtIndex(0)
+        self.assertTrue (frame, "Got a valid frame 0 frame.")
+
+        # Now make sure we can call a method that returns a struct without crashing.
+        cmd_value = frame.EvaluateExpression ("[provider getRange]")
+        self.assertTrue (cmd_value.IsValid())
+
+if __name__ == '__main__':
+    import atexit
+    lldb.SBDebugger.Initialize()
+    atexit.register(lambda: lldb.SBDebugger.Terminate())
+    unittest2.main()

lldb/test/lang/objc/objc-struct-return/test.m

@@ -0,0 +1,23 @@
+#import <Foundation/Foundation.h>
+
+@interface RangeProvider : NSObject {
+};
+-(NSRange)getRange;
+@end
+
+@implementation RangeProvider
+-(NSRange)getRange
+{
+  return NSMakeRange(0, 3);
+}
+@end
+
+int main()
+{
+  @autoreleasepool
+  {
+    RangeProvider *provider = [RangeProvider alloc];
+    NSRange range = [provider getRange]; // Set breakpoint here.
+    return 0;
+  }
+}