https://github.com/dyung updated https://github.com/llvm/llvm-project/pull/213377
>From fa4a3a18db4ce07f2d5c561c419b14c769b90df2 Mon Sep 17 00:00:00 2001 From: Igor Kudrin <[email protected]> Date: Fri, 31 Jul 2026 14:19:53 -0700 Subject: [PATCH] [lldb] Avoid returning a stale AddressOf (#212915) The 'ValueObject::AddressOf()' method assumes that the address of a value object cannot change, so when it is calculated once, it does not need to be updated afterwards. However, this is not the case if the 'ValueObject' is a dependent object obtained by calling 'Dereference()' of another 'ValueObject'. If the latter object is changed, the dependent value object should return a new address from the 'AddressOf()' method to reflect the change. (cherry picked from commit 320164daab4148e3372f6756caaa67882e24a91f) --- lldb/source/ValueObject/ValueObject.cpp | 7 +- .../API/python_api/value/change_ptr/Makefile | 3 + .../value/change_ptr/TestChangePtr.py | 65 +++++++++++++++++++ .../API/python_api/value/change_ptr/main.c | 31 +++++++++ 4 files changed, 103 insertions(+), 3 deletions(-) create mode 100644 lldb/test/API/python_api/value/change_ptr/Makefile create mode 100644 lldb/test/API/python_api/value/change_ptr/TestChangePtr.py create mode 100644 lldb/test/API/python_api/value/change_ptr/main.c diff --git a/lldb/source/ValueObject/ValueObject.cpp b/lldb/source/ValueObject/ValueObject.cpp index cac4933c64325..49fd513c7f578 100644 --- a/lldb/source/ValueObject/ValueObject.cpp +++ b/lldb/source/ValueObject/ValueObject.cpp @@ -2902,9 +2902,6 @@ ValueObjectSP ValueObject::Dereference(Status &error) { } ValueObjectSP ValueObject::AddressOf(Status &error) { - if (m_addr_of_valobj_sp) - return m_addr_of_valobj_sp; - auto [addr, address_type] = GetAddressOf(/*scalar_is_load_address=*/false); error.Clear(); if (addr != LLDB_INVALID_ADDRESS && address_type != eAddressTypeHost) { @@ -2918,6 +2915,10 @@ ValueObjectSP ValueObject::AddressOf(Status &error) { case eAddressTypeFile: case eAddressTypeLoad: { + if (m_addr_of_valobj_sp && + m_addr_of_valobj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS) == addr) + return m_addr_of_valobj_sp; + m_addr_of_valobj_sp.reset(); CompilerType compiler_type = GetCompilerType(); if (compiler_type) { std::string name(1, '&'); diff --git a/lldb/test/API/python_api/value/change_ptr/Makefile b/lldb/test/API/python_api/value/change_ptr/Makefile new file mode 100644 index 0000000000000..10495940055b6 --- /dev/null +++ b/lldb/test/API/python_api/value/change_ptr/Makefile @@ -0,0 +1,3 @@ +C_SOURCES := main.c + +include Makefile.rules diff --git a/lldb/test/API/python_api/value/change_ptr/TestChangePtr.py b/lldb/test/API/python_api/value/change_ptr/TestChangePtr.py new file mode 100644 index 0000000000000..f68eeb8404d70 --- /dev/null +++ b/lldb/test/API/python_api/value/change_ptr/TestChangePtr.py @@ -0,0 +1,65 @@ +import lldb +from lldbsuite.test.decorators import * +from lldbsuite.test.lldbtest import * +from lldbsuite.test import lldbutil + + +class ChangePtrTest(TestBase): + def test(self): + self.build() + + src_file = lldb.SBFileSpec("main.c") + _, process, thread, _ = lldbutil.run_to_source_breakpoint( + self, "// break here 1", src_file + ) + + ## Test 1: The AddressOf of a dereferenced value should change when + ## the pointer value is updated. + + frame = thread.GetFrameAtIndex(0) + p = frame.FindVariable("p") + deref = p.Dereference() + self.assertEqual(deref.GetValueAsUnsigned(), 5) + self.assertEqual(deref.AddressOf().GetValueAsUnsigned(), p.GetValueAsUnsigned()) + thread.StepOver() + self.assertEqual(deref.GetValueAsUnsigned(), 7) + self.assertEqual(deref.AddressOf().GetValueAsUnsigned(), p.GetValueAsUnsigned()) + + ## Test 2: The AddressOf of a child value of a dereferenced value should + ## change when the base pointer updates. + + lldbutil.continue_to_source_breakpoint( + self, process, "// break here 2", src_file + ) + frame = thread.GetFrameAtIndex(0) + p = frame.FindVariable("p") + deref_child = p.Dereference().GetChildMemberWithName("b") + self.assertEqual(deref_child.GetValue(), "'b'") + self.assertEqual( + deref_child.AddressOf().GetValueAsUnsigned(), p.GetValueAsUnsigned() + 1 + ) + thread.StepOver() + self.assertEqual(deref_child.GetValue(), "'d'") + self.assertEqual( + deref_child.AddressOf().GetValueAsUnsigned(), p.GetValueAsUnsigned() + 1 + ) + + ## Test 3: Verify AddressOf updates correctly with persistent expression results. + lldbutil.continue_to_source_breakpoint( + self, process, "// break here 3", src_file + ) + frame = thread.GetFrameAtIndex(0) + frame.EvaluateExpression("int *$ptr = &a") + ptr = frame.FindValue("$ptr", lldb.eValueTypeConstResult) + deref = ptr.Dereference() + self.assertEqual(deref.GetValueAsUnsigned(), 5) + self.assertEqual( + deref.AddressOf().GetValueAsUnsigned(), + frame.FindVariable("a").AddressOf().GetValueAsUnsigned(), + ) + frame.EvaluateExpression("$ptr = &b") + self.assertEqual(deref.GetValueAsUnsigned(), 7) + self.assertEqual( + deref.AddressOf().GetValueAsUnsigned(), + frame.FindVariable("b").AddressOf().GetValueAsUnsigned(), + ) diff --git a/lldb/test/API/python_api/value/change_ptr/main.c b/lldb/test/API/python_api/value/change_ptr/main.c new file mode 100644 index 0000000000000..4cce83e61476c --- /dev/null +++ b/lldb/test/API/python_api/value/change_ptr/main.c @@ -0,0 +1,31 @@ +int test1() { + int a = 5; + int b = 7; + int *p = &a; + p = &b; // break here 1 + return *p; +} + +char test2() { + struct S { + char a; + char b; + }; + struct S arr[2] = {{'a', 'b'}, {'c', 'd'}}; + struct S *p = arr; + ++p; // break here 2 + return p->b; +} + +int test3() { + int a = 5; + int b = 7; + return a + b; // break here 3 +} + +int main() { + test1(); + test2(); + test3(); + return 0; +} _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
