diff --git a/lldb/source/Core/ValueObject.cpp b/lldb/source/Core/ValueObject.cpp --- a/lldb/source/Core/ValueObject.cpp +++ b/lldb/source/Core/ValueObject.cpp @@ -273,8 +273,6 @@ return compiler_type; } - - DataExtractor &ValueObject::GetDataExtractor() { UpdateValueIfNeeded(false); return m_data; @@ -409,8 +407,9 @@ return root; } -lldb::ValueObjectSP ValueObject::GetChildAtIndexPath( - llvm::ArrayRef> idxs, size_t *index_of_error) { +lldb::ValueObjectSP +ValueObject::GetChildAtIndexPath(llvm::ArrayRef> idxs, + size_t *index_of_error) { if (idxs.size() == 0) return GetSP(); ValueObjectSP root(GetSP()); @@ -1185,9 +1184,10 @@ { Status error; lldb::WritableDataBufferSP buffer_sp; - std::pair read_string = ReadPointedString( - buffer_sp, error, 0, (custom_format == eFormatVectorOfChar) || - (custom_format == eFormatCharArray)); + std::pair read_string = + ReadPointedString(buffer_sp, error, 0, + (custom_format == eFormatVectorOfChar) || + (custom_format == eFormatCharArray)); lldb_private::formatters::StringPrinter:: ReadBufferAndDumpToStreamOptions options(*this); options.SetData(DataExtractor( @@ -1552,8 +1552,7 @@ return false; } -void ValueObject::AddSyntheticChild(ConstString key, - ValueObject *valobj) { +void ValueObject::AddSyntheticChild(ConstString key, ValueObject *valobj) { m_synthetic_children[key] = valobj; } @@ -1924,64 +1923,96 @@ return; } - const bool is_deref_of_parent = IsDereferenceOfParent(); + // Checks whether a value is dereference of a non-reference parent. + // This is used to determine whether to print a dereference operation (*). + auto is_deref_of_non_reference = [](ValueObject *value) { + if (value == nullptr) + return false; + ValueObject *value_parent = value->GetParent(); + if (value_parent) { + CompilerType parent_compiler_type = value_parent->GetCompilerType(); + if (parent_compiler_type) { + const uint32_t parent_type_info = parent_compiler_type.GetTypeInfo(); + if (parent_type_info & eTypeIsReference) + return false; + } + } + return value->IsDereferenceOfParent(); + }; + + ValueObject *parent = GetParent(); - if (is_deref_of_parent && + if (is_deref_of_non_reference(this) && epformat == eGetExpressionPathFormatDereferencePointers) { // this is the original format of GetExpressionPath() producing code like // *(a_ptr).memberName, which is entirely fine, until you put this into // StackFrame::GetValueForVariableExpressionPath() which prefers to see - // a_ptr->memberName. the eHonorPointers mode is meant to produce strings - // in this latter format + // a_ptr->memberName. The eHonorPointers mode is meant to produce strings + // in this latter format. s.PutCString("*("); + if (parent) + parent->GetExpressionPath(s, epformat); + s.PutChar(')'); + return; } - ValueObject *parent = GetParent(); - - if (parent) - parent->GetExpressionPath(s, epformat); - - // if we are a deref_of_parent just because we are synthetic array members - // made up to allow ptr[%d] syntax to work in variable printing, then add our - // name ([%d]) to the expression path - if (m_flags.m_is_array_item_for_pointer && - epformat == eGetExpressionPathFormatHonorPointers) - s.PutCString(m_name.GetStringRef()); - - if (!IsBaseClass()) { - if (!is_deref_of_parent) { - ValueObject *non_base_class_parent = GetNonBaseClassParent(); - if (non_base_class_parent && - !non_base_class_parent->GetName().IsEmpty()) { - CompilerType non_base_class_parent_compiler_type = - non_base_class_parent->GetCompilerType(); - if (non_base_class_parent_compiler_type) { - if (parent && parent->IsDereferenceOfParent() && - epformat == eGetExpressionPathFormatHonorPointers) { - s.PutCString("->"); - } else { - const uint32_t non_base_class_parent_type_info = - non_base_class_parent_compiler_type.GetTypeInfo(); - - if (non_base_class_parent_type_info & eTypeIsPointer) { - s.PutCString("->"); - } else if ((non_base_class_parent_type_info & eTypeHasChildren) && - !(non_base_class_parent_type_info & eTypeIsArray)) { - s.PutChar('.'); - } + const bool is_deref_of_parent = IsDereferenceOfParent(); + bool is_parent_deref_of_non_reference = false; + bool print_obj_access = false; + bool print_ptr_access = false; + + if (!IsBaseClass() && !is_deref_of_parent) { + ValueObject *non_base_class_parent = GetNonBaseClassParent(); + if (non_base_class_parent && !non_base_class_parent->GetName().IsEmpty()) { + CompilerType non_base_class_parent_compiler_type = + non_base_class_parent->GetCompilerType(); + if (non_base_class_parent_compiler_type) { + if (parent && parent->IsDereferenceOfParent() && + epformat == eGetExpressionPathFormatHonorPointers) { + print_ptr_access = true; + } else { + const uint32_t non_base_class_parent_type_info = + non_base_class_parent_compiler_type.GetTypeInfo(); + + if (non_base_class_parent_type_info & eTypeIsPointer) { + print_ptr_access = true; + } else if ((non_base_class_parent_type_info & eTypeHasChildren) && + !(non_base_class_parent_type_info & eTypeIsArray)) { + print_obj_access = true; } } } - - const char *name = GetName().GetCString(); - if (name) - s.PutCString(name); + is_parent_deref_of_non_reference = + is_deref_of_non_reference(non_base_class_parent); } } - if (is_deref_of_parent && - epformat == eGetExpressionPathFormatDereferencePointers) { - s.PutChar(')'); + if (parent) { + // The parent should be wrapped in parenthesis when doing a member access. + // This prevents forming incorrect expressions such as *(ptr).field, + // which dereferences the field instead of the ptr, and constructs the + // expression in the format (*(ptr)).field. To create expressions compatible + // with StackFrame::GetValueForVariableExpressionPath() and reduce amount of + // unnecessary parenthesis, this is done only when the parent has the + // dereference syntax *(parent). + const bool wrap_parent_in_parens = (print_obj_access || print_ptr_access) && + is_parent_deref_of_non_reference; + if (wrap_parent_in_parens) + s.PutChar('('); + parent->GetExpressionPath(s, epformat); + if (wrap_parent_in_parens) + s.PutChar(')'); + } + + if (print_obj_access) + s.PutChar('.'); + if (print_ptr_access) + s.PutCString("->"); + + if (!IsBaseClass() && !is_deref_of_parent) { + const char *name = GetName().GetCString(); + if (name) + s.PutCString(name); } } @@ -3108,8 +3139,6 @@ return (!type.IsValid()) || (0 != (type.GetTypeInfo() & eTypeHasValue)); } - - ValueObjectSP ValueObject::Persist() { if (!UpdateValueIfNeeded()) return nullptr; diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp --- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp +++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp @@ -6562,6 +6562,8 @@ child_is_base_class, tmp_child_is_deref_of_parent, valobj, language_flags); } else { + child_is_deref_of_parent = true; + const char *parent_name = valobj ? valobj->GetName().GetCString() : nullptr; if (parent_name) { diff --git a/lldb/test/API/python_api/expression_path/Makefile b/lldb/test/API/python_api/expression_path/Makefile new file mode 100644 --- /dev/null +++ b/lldb/test/API/python_api/expression_path/Makefile @@ -0,0 +1,3 @@ +CXX_SOURCES := main.cpp + +include Makefile.rules diff --git a/lldb/test/API/python_api/expression_path/TestExpressionPath.py b/lldb/test/API/python_api/expression_path/TestExpressionPath.py new file mode 100644 --- /dev/null +++ b/lldb/test/API/python_api/expression_path/TestExpressionPath.py @@ -0,0 +1,119 @@ +"""Test that SBFrame::GetExpressionPath construct valid expressions""" + + +import lldb +from lldbsuite.test.decorators import * +from lldbsuite.test.lldbtest import * +from lldbsuite.test import lldbutil + + +class SBValueGetExpressionPathTest(TestBase): + NO_DEBUG_INFO_TESTCASE = True + + def path(self, value): + """Constructs the expression path given the SBValue""" + if not value: + return None + stream = lldb.SBStream() + if not value.GetExpressionPath(stream): + return None + return stream.GetData() + + def test_expression_path(self): + """Test that SBFrame::GetExpressionPath construct valid expressions""" + self.build() + self.setTearDownCleanup() + + exe = self.getBuildArtifact("a.out") + + # Create the target + target = self.dbg.CreateTarget(exe) + self.assertTrue(target, VALID_TARGET) + + # Set the breakpoints + breakpoint = target.BreakpointCreateBySourceRegex( + 'Set breakpoint here', lldb.SBFileSpec("main.cpp")) + self.assertTrue(breakpoint.GetNumLocations() > 0, VALID_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, PROCESS_IS_VALID) + + # Frame #0 should be at our breakpoint. + threads = lldbutil.get_threads_stopped_at_breakpoint( + process, breakpoint) + + self.assertEquals(len(threads), 1) + self.thread = threads[0] + self.frame = self.thread.frames[0] + self.assertTrue(self.frame, "Frame 0 is valid.") + + # Find "b" variables in frame + b = self.frame.FindVariable("b") + bp = self.frame.FindVariable("b_ptr") + br = self.frame.FindVariable("b_ref") + bpr = self.frame.FindVariable("b_ptr_ref") + # Check expression paths + self.assertEqual(self.path(b), "b") + self.assertEqual(self.path(bp), "b_ptr") + self.assertEqual(self.path(br), "b_ref") + self.assertEqual(self.path(bpr), "b_ptr_ref") + + # Dereference "b" pointers + bp_deref = bp.Dereference() + bpr_deref = bpr.Dereference() # a pointer + bpr_deref2 = bpr_deref.Dereference() # two Dereference() calls to get object + # Check expression paths + self.assertEqual(self.path(bp_deref), "*(b_ptr)") + self.assertEqual(self.path(bpr_deref), "b_ptr_ref") + self.assertEqual(self.path(bpr_deref2), "*(b_ptr_ref)") + + # Access "b" members and check expression paths + self.assertEqual(self.path(b.GetChildMemberWithName("x")), "b.x") + self.assertEqual(self.path(bp.GetChildMemberWithName("x")), "b_ptr->x") + self.assertEqual(self.path(br.GetChildMemberWithName("x")), "b_ref.x") + self.assertEqual(self.path(bp_deref.GetChildMemberWithName("x")), "(*(b_ptr)).x") + self.assertEqual(self.path(bpr_deref.GetChildMemberWithName("x")), "b_ptr_ref->x") + self.assertEqual(self.path(bpr_deref2.GetChildMemberWithName("x")), "(*(b_ptr_ref)).x") + # TODO: Uncomment once accessing members on pointer references is supported. + # self.assertEqual(self.path(bpr.GetChildMemberWithName("x")), "b_ptr_ref->x") + + # Try few expressions with multiple member access + bp_ar_x = bp.GetChildMemberWithName("a_ref").GetChildMemberWithName("x") + br_ar_y = br.GetChildMemberWithName("a_ref").GetChildMemberWithName("y") + self.assertEqual(self.path(bp_ar_x), "b_ptr->a_ref.x") + self.assertEqual(self.path(br_ar_y), "b_ref.a_ref.y") + bpr_deref_apr_deref = bpr_deref.GetChildMemberWithName("a_ptr_ref").Dereference() + bpr_deref_apr_deref2 = bpr_deref_apr_deref.Dereference() + self.assertEqual(self.path(bpr_deref_apr_deref), "b_ptr_ref->a_ptr_ref") + self.assertEqual(self.path(bpr_deref_apr_deref2), "*(b_ptr_ref->a_ptr_ref)") + bpr_deref_apr_deref_x = bpr_deref_apr_deref.GetChildMemberWithName("x") + bpr_deref_apr_deref2_x = bpr_deref_apr_deref2.GetChildMemberWithName("x") + self.assertEqual(self.path(bpr_deref_apr_deref_x), "b_ptr_ref->a_ptr_ref->x") + self.assertEqual(self.path(bpr_deref_apr_deref2_x), "(*(b_ptr_ref->a_ptr_ref)).x") + + # Find "c" variables in frame + c = self.frame.FindVariable("c") + cp = self.frame.FindVariable("c_ptr") + cr = self.frame.FindVariable("c_ref") + cpr = self.frame.FindVariable("c_ptr_ref") + # Dereference pointers + cp_deref = cp.Dereference() + cpr_deref = cpr.Dereference() # a pointer + cpr_deref2 = cpr_deref.Dereference() # two Dereference() calls to get object + # Check expression paths + self.assertEqual(self.path(cp_deref), "*(c_ptr)") + self.assertEqual(self.path(cpr_deref), "c_ptr_ref") + self.assertEqual(self.path(cpr_deref2), "*(c_ptr_ref)") + + # Access members on "c" variables and check expression paths + self.assertEqual(self.path(c.GetChildMemberWithName("x")), "c.x") + self.assertEqual(self.path(cp.GetChildMemberWithName("x")), "c_ptr->x") + self.assertEqual(self.path(cr.GetChildMemberWithName("x")), "c_ref.x") + self.assertEqual(self.path(cp_deref.GetChildMemberWithName("x")), "(*(c_ptr)).x") + self.assertEqual(self.path(cpr_deref.GetChildMemberWithName("x")), "c_ptr_ref->x") + self.assertEqual(self.path(cpr_deref2.GetChildMemberWithName("x")), "(*(c_ptr_ref)).x") + # TODO: Uncomment once accessing members on pointer references is supported. + # self.assertEqual(self.path(cpr.GetChildMemberWithName("x")), "c_ptr_ref->x") \ No newline at end of file diff --git a/lldb/test/API/python_api/expression_path/main.cpp b/lldb/test/API/python_api/expression_path/main.cpp new file mode 100644 --- /dev/null +++ b/lldb/test/API/python_api/expression_path/main.cpp @@ -0,0 +1,34 @@ +struct StructA { + int x; + int y; +}; + +struct StructB { + int x; + StructA &a_ref; + StructA *&a_ptr_ref; +}; + +struct StructC : public StructB { + int y; + + StructC(int x, StructA &a_ref, StructA *&a_ref_ptr, int y) + : StructB{x, a_ref, a_ref_ptr}, y(y) {} +}; + +int main() { + StructA a{1, 2}; + StructA *a_ptr = &a; + + StructB b{3, a, a_ptr}; + StructB *b_ptr = &b; + StructB &b_ref = b; + StructB *&b_ptr_ref = b_ptr; + + StructC c(4, a, a_ptr, 5); + StructC *c_ptr = &c; + StructC &c_ref = c; + StructC *&c_ptr_ref = c_ptr; + + return 0; // Set breakpoint here +} \ No newline at end of file