From 48b32f4cedc1021c774b68ddff1fb9b338c751c0 Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Mon, 22 Jan 2018 23:53:56 +0000 Subject: [lldb] Fix some C++ virtual method call bugs in LLDB expression evaluation by building method override tables for CXXMethodDecls in DWARFASTParserClang::CompleteTypeFromDWARF. C++ virtual method calls in LLDB expressions may fail if the override table for the method being called is not correct as IRGen will produce references to the wrong (or a missing) vtable entry. This patch does not fix calls to virtual methods with covariant return types as it mistakenly treats these as overloads, rather than overrides. This will be addressed in a future patch. Review: https://reviews.llvm.org/D41997 Partially fixes llvm-svn: 323163 --- .../TestCallOverriddenMethod.py | 47 ++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 lldb/packages/Python/lldbsuite/test/expression_command/call-overridden-method/TestCallOverriddenMethod.py (limited to 'lldb/packages/Python/lldbsuite/test/expression_command/call-overridden-method/TestCallOverriddenMethod.py') diff --git a/lldb/packages/Python/lldbsuite/test/expression_command/call-overridden-method/TestCallOverriddenMethod.py b/lldb/packages/Python/lldbsuite/test/expression_command/call-overridden-method/TestCallOverriddenMethod.py new file mode 100644 index 00000000000..54709e26ecb --- /dev/null +++ b/lldb/packages/Python/lldbsuite/test/expression_command/call-overridden-method/TestCallOverriddenMethod.py @@ -0,0 +1,47 @@ +""" +Test calling an overriden method. + +Note: + This verifies that LLDB is correctly building the method overrides table. + If this table is not built correctly then calls to overridden methods in + derived classes may generate references to non-existant vtable entries, + as the compiler treats the overridden method as a totally new virtual + method definition. + + +""" + +import lldb +from lldbsuite.test.decorators import * +from lldbsuite.test.lldbtest import * +from lldbsuite.test import lldbutil + +class ExprCommandCallOverriddenMethod(TestBase): + + mydir = TestBase.compute_mydir(__file__) + + def setUp(self): + # Call super's setUp(). + TestBase.setUp(self) + # Find the line number to break for main.c. + self.line = line_number('main.cpp', '// Set breakpoint here') + + def test(self): + """Test calls to overridden methods in derived classes.""" + self.build() + + # Set breakpoint in main and run exe + self.runCmd("file a.out", CURRENT_EXECUTABLE_SET) + lldbutil.run_break_set_by_file_and_line( + self, "main.cpp", self.line, num_expected_locations=-1, loc_exact=True) + + self.runCmd("run", RUN_SUCCEEDED) + + # Test call to method in base class (this should always work as the base + # class method is never an override). + self.expect("expr b->foo()") + + # Test call to overridden method in derived class (this will fail if the + # overrides table is not correctly set up, as Derived::foo will be assigned + # a vtable entry that does not exist in the compiled program). + self.expect("expr d.foo()") -- cgit v1.2.3