Constant result ValueObjects are - well - constant

And they also do not have a thread/frame attached to them

That makes dynamic and synthetic values attached to them impossible to update - which, among other things, makes it impossible to properly display persistent variables of types that could have such dynamic/persistent values

Fix this by making it so that a ValueObject can control its constantness (hint: dynamic and synthetic values cannot be constant) and whether it wants to let itself be updated when an invalid thread is around

llvm-svn: 237504

3 files changed, 73 insertions, 0 deletions

diff --git a/lldb/test/expression_command/persistent_ptr_update/Makefile b/lldb/test/expression_command/persistent_ptr_update/Makefile
new file mode 100644
index 00000000000..db5f575866d
--- /dev/null
+++ b/lldb/test/expression_command/persistent_ptr_update/Makefile
@@ -0,0 +1,7 @@
+LEVEL = ../../make
+
+C_SOURCES := main.c
+
+include $(LEVEL)/Makefile.rules
+
+
diff --git a/lldb/test/expression_command/persistent_ptr_update/TestPersistentPtrUpdate.py b/lldb/test/expression_command/persistent_ptr_update/TestPersistentPtrUpdate.py
new file mode 100644
index 00000000000..9c291219529
--- /dev/null
+++ b/lldb/test/expression_command/persistent_ptr_update/TestPersistentPtrUpdate.py
@@ -0,0 +1,55 @@
+"""
+Test that we can have persistent pointer variables
+"""
+
+import unittest2
+import lldb
+import lldbutil
+from lldbtest import *
+
+class PersistentPtrUpdateTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+
+    @skipUnlessDarwin
+    @dsym_test
+    def test_with_dsym(self):
+        """Test that we can have persistent pointer variables"""
+        self.buildDsym()
+        self.do_my_test()
+
+    @skipUnlessDarwin
+    @dwarf_test
+    def test_with_dwarf(self):
+        """Test that we can have persistent pointer variables"""
+        self.buildDwarf()
+        self.do_my_test()
+
+    def do_my_test(self):
+        def cleanup():
+            pass
+        
+        # Execute the cleanup function during test case tear down.
+        self.addTearDownHook(cleanup)
+
+        self.runCmd("file a.out", CURRENT_EXECUTABLE_SET)
+        
+        self.runCmd('break set -p here')
+
+        self.runCmd("run", RUN_SUCCEEDED)
+        
+        self.runCmd("expr void* $foo = nullptr")
+        
+        self.runCmd("continue")
+        
+        self.expect("expr $foo", substrs=['$foo','0x0'])
+
+if __name__ == '__main__':
+    import atexit
+    lldb.SBDebugger.Initialize()
+    atexit.register(lambda: lldb.SBDebugger.Terminate())
+    unittest2.main()
diff --git a/lldb/test/expression_command/persistent_ptr_update/main.c b/lldb/test/expression_command/persistent_ptr_update/main.c
new file mode 100644
index 00000000000..73346969ecc
--- /dev/null
+++ b/lldb/test/expression_command/persistent_ptr_update/main.c
@@ -0,0 +1,11 @@
+void* foo(void *p)
+{
+  return p; // break here
+}
+
+int main() {
+  while (1) {
+    foo(0);
+  }
+  return 0;
+}