================ @@ -0,0 +1,273 @@ +//===-- DILEval.cpp -------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "lldb/ValueObject/DILEval.h" +#include "lldb/Symbol/VariableList.h" +#include "lldb/Target/RegisterContext.h" +#include "lldb/ValueObject/DILAST.h" +#include "lldb/ValueObject/ValueObject.h" +#include "lldb/ValueObject/ValueObjectRegister.h" +#include "lldb/ValueObject/ValueObjectVariable.h" +#include "llvm/Support/FormatAdapters.h" +#include <memory> + +namespace lldb_private::dil { + +static lldb::ValueObjectSP LookupStaticIdentifier( + VariableList &variable_list, std::shared_ptr<StackFrame> exe_scope, + llvm::StringRef name_ref, llvm::StringRef unqualified_name) { + // First look for an exact match to the (possibly) qualified name. + for (const lldb::VariableSP &var_sp : variable_list) { + lldb::ValueObjectSP valobj_sp( + ValueObjectVariable::Create(exe_scope.get(), var_sp)); + if (valobj_sp && valobj_sp->GetVariable() && + (valobj_sp->GetVariable()->NameMatches(ConstString(name_ref)))) + return valobj_sp; + } + + // If the qualified name is the same as the unqualfied name, there's nothing + // more to be done. + if (name_ref == unqualified_name) + return nullptr; + + // We didn't match the qualified name; try to match the unqualified name. + for (const lldb::VariableSP &var_sp : variable_list) { + lldb::ValueObjectSP valobj_sp( + ValueObjectVariable::Create(exe_scope.get(), var_sp)); + if (valobj_sp && valobj_sp->GetVariable() && + (valobj_sp->GetVariable()->NameMatches(ConstString(unqualified_name)))) + return valobj_sp; + } + + return nullptr; +} + +static lldb::VariableSP DILFindVariable(ConstString name, + lldb::VariableListSP variable_list) { + lldb::VariableSP exact_match; + std::vector<lldb::VariableSP> possible_matches; + + typedef std::vector<lldb::VariableSP> collection; + typedef collection::iterator iterator; + + iterator pos, end = variable_list->end(); + for (pos = variable_list->begin(); pos != end; ++pos) { + llvm::StringRef str_ref_name = pos->get()->GetName().GetStringRef(); + // Check for global vars, which might start with '::'. + str_ref_name.consume_front("::"); + + if (str_ref_name == name.GetStringRef()) + possible_matches.push_back(*pos); + else if (pos->get()->NameMatches(name)) + possible_matches.push_back(*pos); + } + + // Look for exact matches (favors local vars over global vars) + auto exact_match_it = + llvm::find_if(possible_matches, [&](lldb::VariableSP var_sp) { + return var_sp->GetName() == name; + }); + + if (exact_match_it != possible_matches.end()) + exact_match = *exact_match_it; + + if (!exact_match) + // Look for a global var exact match. + for (auto var_sp : possible_matches) { + llvm::StringRef str_ref_name = var_sp->GetName().GetStringRef(); + str_ref_name.consume_front("::"); + if (str_ref_name == name.GetStringRef()) { + exact_match = var_sp; + break; + } + } + + if (!exact_match && possible_matches.size() == 1) + exact_match = possible_matches[0]; + + return exact_match; +} + +std::unique_ptr<IdentifierInfo> LookupGlobalIdentifier( + llvm::StringRef name_ref, std::shared_ptr<StackFrame> stack_frame, + lldb::TargetSP target_sp, lldb::DynamicValueType use_dynamic, + CompilerType *scope_ptr) { + // First look for match in "local" global variables. + lldb::VariableListSP variable_list(stack_frame->GetInScopeVariableList(true)); + name_ref.consume_front("::"); + + lldb::ValueObjectSP value_sp; + if (variable_list) { + lldb::VariableSP var_sp = + DILFindVariable(ConstString(name_ref), variable_list); + if (var_sp) + value_sp = + stack_frame->GetValueObjectForFrameVariable(var_sp, use_dynamic); + } + + if (value_sp) + return IdentifierInfo::FromValue(*value_sp); + + // Also check for static global vars. + if (variable_list) { + const char *type_name = ""; + if (scope_ptr) + type_name = scope_ptr->GetCanonicalType().GetTypeName().AsCString(); + std::string name_with_type_prefix = + llvm::formatv("{0}::{1}", type_name, name_ref).str(); + value_sp = LookupStaticIdentifier(*variable_list, stack_frame, + name_with_type_prefix, name_ref); + if (!value_sp) + value_sp = LookupStaticIdentifier(*variable_list, stack_frame, name_ref, + name_ref); + } + + if (value_sp) + return IdentifierInfo::FromValue(*value_sp); + + // Check for match in modules global variables. + VariableList modules_var_list; + target_sp->GetImages().FindGlobalVariables( + ConstString(name_ref), std::numeric_limits<uint32_t>::max(), + modules_var_list); + if (modules_var_list.Empty()) + return nullptr; + + for (const lldb::VariableSP &var_sp : modules_var_list) { + std::string qualified_name = llvm::formatv("::{0}", name_ref).str(); + if (var_sp->NameMatches(ConstString(name_ref)) || + var_sp->NameMatches(ConstString(qualified_name))) { + value_sp = ValueObjectVariable::Create(stack_frame.get(), var_sp); + break; + } + } + + if (value_sp) + return IdentifierInfo::FromValue(*value_sp); + + return nullptr; +} + +std::unique_ptr<IdentifierInfo> +LookupIdentifier(llvm::StringRef name_ref, + std::shared_ptr<StackFrame> stack_frame, + lldb::DynamicValueType use_dynamic, CompilerType *scope_ptr) { + // Support $rax as a special syntax for accessing registers. + // Will return an invalid value in case the requested register doesn't exist. + if (name_ref.consume_front("$")) { + lldb::ValueObjectSP value_sp; + + lldb::RegisterContextSP reg_ctx(stack_frame->GetRegisterContext()); + if (!reg_ctx) + return nullptr; + + if (const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName(name_ref)) + value_sp = + ValueObjectRegister::Create(stack_frame.get(), reg_ctx, reg_info); + + if (value_sp) + return IdentifierInfo::FromValue(*value_sp); + + return nullptr; + } + + lldb::VariableListSP variable_list( + stack_frame->GetInScopeVariableList(false)); + + if (!name_ref.contains("::")) { + if (!scope_ptr || !scope_ptr->IsValid()) { + // Lookup in the current frame. + // Try looking for a local variable in current scope. + lldb::ValueObjectSP value_sp; + if (variable_list) { + lldb::VariableSP var_sp = + DILFindVariable(ConstString(name_ref), variable_list); + if (var_sp) + value_sp = + stack_frame->GetValueObjectForFrameVariable(var_sp, use_dynamic); + } + if (!value_sp) + value_sp = stack_frame->FindVariable(ConstString(name_ref)); + + if (value_sp) + return IdentifierInfo::FromValue(*value_sp); + + // Try looking for an instance variable (class member). + SymbolContext sc = stack_frame->GetSymbolContext( + lldb::eSymbolContextFunction | lldb::eSymbolContextBlock); + llvm::StringRef ivar_name = sc.GetInstanceVariableName(); + value_sp = stack_frame->FindVariable(ConstString(ivar_name)); + if (value_sp) + value_sp = value_sp->GetChildMemberWithName(name_ref); + + if (value_sp) + return IdentifierInfo::FromValue(*(value_sp)); + } + } + return nullptr; +} + +Interpreter::Interpreter(lldb::TargetSP target, llvm::StringRef expr, + lldb::DynamicValueType use_dynamic, + std::shared_ptr<StackFrame> frame_sp) + : m_target(std::move(target)), m_expr(expr), m_default_dynamic(use_dynamic), + m_exe_ctx_scope(frame_sp) {} + +llvm::Expected<lldb::ValueObjectSP> +Interpreter::DILEvalNode(const ASTNode *node) { + + // Traverse an AST pointed by the `node`. + auto value_or_error = node->Accept(this); + + // Return the computed value or error. + return value_or_error; +} + +llvm::Expected<lldb::ValueObjectSP> +Interpreter::Visit(const IdentifierNode *node) { + lldb::DynamicValueType use_dynamic = node->GetUseDynamic(); + + std::unique_ptr<IdentifierInfo> identifier = + LookupIdentifier(node->GetName(), m_exe_ctx_scope, use_dynamic); + + if (!identifier) + identifier = LookupGlobalIdentifier(node->GetName(), m_exe_ctx_scope, + m_target, use_dynamic); + if (!identifier) { + std::string errMsg; + std::string name = node->GetName(); + errMsg = llvm::formatv("use of undeclared identifier '{0}'", name); + Status error = Status( + (uint32_t)ErrorCode::kUndeclaredIdentifier, lldb::eErrorTypeGeneric, + FormatDiagnostics(m_expr, errMsg, node->GetLocation())); + return error.ToError(); + } + lldb::ValueObjectSP val; + lldb::TargetSP target_sp; + Status error; + + assert(identifier->GetKind() == IdentifierInfo::Kind::eValue && + "Unrecognized identifier kind"); + + val = identifier->GetValue(); + + if (val->GetCompilerType().IsReferenceType()) { + Status error; + val = val->Dereference(error); + if (error.Fail()) + return error.ToError(); + } ---------------- labath wrote:
I don't think we actually want this (here). If the user accesses a reference type, we should show them that they're accessing a reference. Can you compare the behavior of this implementation with/without this block with the current implementation of "frame variable"? Which one is a better match? https://github.com/llvm/llvm-project/pull/120971 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
