Create new test for expression evaluation where char type matters

[tberghammer]

Summary

Create new test for expression evaluation where char type matters

char is a special type in C++ which can be signed/unsigned and have to
be distinguished both from "signed char" and from "unsigned char". This
test check for this behavior during the expression evaluation with
different compiler settings.

[tberghammer]

Passes on Linux (x86_64) and on Mac (x86_64) with XFAIL. I haven't tested it on other architectures/OSes. If you see failure in some environment then please let m know so I can XFAIL it accordingly.

[ovyalov]

test/expression_command/char/TestExprsChar.py

58

Could you attach the bug id here?

[tberghammer]

Add bug number for XFAIL

[clayborg]

lgtm

[ovyalov]

Looks good.

test/expression_command/char/Makefile

+LEVEL = ../../make
+
+CXX_SOURCES := main.cpp
+
+include $(LEVEL)/Makefile.rules

test/expression_command/char/TestExprsChar.py

+import unittest2
+import lldb
+import lldbutil
+from lldbtest import *
+
+class ExprCharTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+
+        self.main_source = "main.cpp"
+        self.main_source_spec = lldb.SBFileSpec (self.main_source)
+        self.exe = os.path.join(os.getcwd(), "a.out")
+
+    def do_test(self, dictionary=None):
+        """These basic expression commands should work as expected."""
+        self.buildDefault(dictionary = dictionary)
+
+        target = self.dbg.CreateTarget(self.exe)
+        self.assertTrue(target)
+
+        breakpoint = target.BreakpointCreateBySourceRegex('// Break here', self.main_source_spec)
+        self.assertTrue(breakpoint)
+
+        # Launch the process, and do not stop at the entry point.
+        process = target.LaunchSimple(None, None, self.get_process_working_directory())
+        self.assertTrue(process)
+
+        threads = lldbutil.get_threads_stopped_at_breakpoint(process, breakpoint)
+        self.assertEqual(len(threads), 1)
+
+        frame = threads[0].GetFrameAtIndex(0)
+
+        value = frame.EvaluateExpression("foo(c)")
+        self.assertTrue(value.IsValid())
+        self.assertTrue(value.GetError().Success())
+        self.assertEqual(value.GetValueAsSigned(0), 1)
+
+        value = frame.EvaluateExpression("foo(sc)")
+        self.assertTrue(value.IsValid())
+        self.assertTrue(value.GetError().Success())
+        self.assertEqual(value.GetValueAsSigned(0), 2)
+
+        value = frame.EvaluateExpression("foo(uc)")
+        self.assertTrue(value.IsValid())
+        self.assertTrue(value.GetError().Success())
+        self.assertEqual(value.GetValueAsSigned(0), 3)
+
+    def test_default_char(self):
+        self.do_test()
+
+    def test_signed_char(self):
+        self.do_test(dictionary={'CFLAGS_EXTRAS': '-fsigned-char'})
+
+    @expectedFailurex86_64
+    def test_unsigned_char(self):
+        self.do_test(dictionary={'CFLAGS_EXTRAS': '-funsigned-char'})
+
+if __name__ == '__main__':
+    import atexit
+    lldb.SBDebugger.Initialize()
+    atexit.register(lambda: lldb.SBDebugger.Terminate())
+    unittest2.main()

test/expression_command/char/main.cpp

+int foo(char c) { return 1; }
+int foo(signed char c) { return 2; }
+int foo(unsigned char c) { return 3; }
+
+int main() {
+  char c = 0;
+  signed char sc = 0;
+  unsigned char uc = 0;
+  return 0; // Break here
+}