[Expressions] Add support of expressions evaluation in some object's context
Summary:
This patch adds support of expression evaluation in a context of some object.
Consider the following example:
```
struct S {
int a = 11;
int b = 12;
};
int main() {
S s;
int a = 1;
int b = 2;
// We have stopped here
return 0;
}
```
This patch allows to do something like that:
```
lldb.frame.FindVariable("s").EvaluateExpression("a + b")
```
and the result will be `33` (not `3`) because fields `a` and `b` of `s` will be
used (not locals `a` and `b`).
This is achieved by replacing of `this` type and object for the expression. This
has some limitations: an expression can be evaluated only for values located in
the debuggee process memory (they must have an address of `eAddressTypeLoad`
type).
Reviewers: teemperor, clayborg, jingham, zturner, labath, davide, spyffe, serge-sans-paille
Reviewed By: jingham
Subscribers: abidh, lldb-commits, leonid.mashinskiy
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D55318
llvm-svn: 353149
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
index 745341b..6e7f11f 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
@@ -65,10 +65,12 @@
ClangExpressionDeclMap::ClangExpressionDeclMap(
bool keep_result_in_memory,
Materializer::PersistentVariableDelegate *result_delegate,
- ExecutionContext &exe_ctx)
+ ExecutionContext &exe_ctx,
+ ValueObject *ctx_obj)
: ClangASTSource(exe_ctx.GetTargetSP()), m_found_entities(),
m_struct_members(), m_keep_result_in_memory(keep_result_in_memory),
- m_result_delegate(result_delegate), m_parser_vars(), m_struct_vars() {
+ m_result_delegate(result_delegate), m_parser_vars(), m_struct_vars(),
+ m_ctx_obj(ctx_obj) {
EnableStructVars();
}
@@ -927,6 +929,21 @@
static ConstString g_lldb_class_name("$__lldb_class");
if (name == g_lldb_class_name) {
+ if (m_ctx_obj) {
+ Status status;
+ lldb::ValueObjectSP ctx_obj_ptr = m_ctx_obj->AddressOf(status);
+ if (!ctx_obj_ptr || status.Fail())
+ return;
+
+ AddThisType(context, TypeFromUser(m_ctx_obj->GetCompilerType()),
+ current_id);
+
+ m_struct_vars->m_object_pointer_type =
+ TypeFromUser(ctx_obj_ptr->GetCompilerType());
+
+ return;
+ }
+
// Clang is looking for the type of "this"
if (frame == NULL)
@@ -1019,6 +1036,21 @@
static ConstString g_lldb_objc_class_name("$__lldb_objc_class");
if (name == g_lldb_objc_class_name) {
+ if (m_ctx_obj) {
+ Status status;
+ lldb::ValueObjectSP ctx_obj_ptr = m_ctx_obj->AddressOf(status);
+ if (!ctx_obj_ptr || status.Fail())
+ return;
+
+ AddOneType(context, TypeFromUser(m_ctx_obj->GetCompilerType()),
+ current_id);
+
+ m_struct_vars->m_object_pointer_type =
+ TypeFromUser(ctx_obj_ptr->GetCompilerType());
+
+ return;
+ }
+
// Clang is looking for the type of "*self"
if (!frame)
@@ -2124,7 +2156,7 @@
}
void ClangExpressionDeclMap::AddThisType(NameSearchContext &context,
- TypeFromUser &ut,
+ const TypeFromUser &ut,
unsigned int current_id) {
CompilerType copied_clang_type = GuardedCopyType(ut);
@@ -2198,7 +2230,7 @@
}
void ClangExpressionDeclMap::AddOneType(NameSearchContext &context,
- TypeFromUser &ut,
+ const TypeFromUser &ut,
unsigned int current_id) {
CompilerType copied_clang_type = GuardedCopyType(ut);
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.h b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.h
index d860979..ac6690d 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.h
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.h
@@ -72,11 +72,16 @@
///
/// @param[in] exe_ctx
/// The execution context to use when parsing.
+ ///
+ /// @param[in] ctx_obj
+ /// If not empty, then expression is evaluated in context of this object.
+ /// See the comment to `UserExpression::Evaluate` for details.
//------------------------------------------------------------------
ClangExpressionDeclMap(
bool keep_result_in_memory,
Materializer::PersistentVariableDelegate *result_delegate,
- ExecutionContext &exe_ctx);
+ ExecutionContext &exe_ctx,
+ ValueObject *ctx_obj);
//------------------------------------------------------------------
/// Destructor
@@ -343,6 +348,10 @@
Materializer::PersistentVariableDelegate
*m_result_delegate; ///< If non-NULL, used to report expression results to
///ClangUserExpression.
+ ValueObject *m_ctx_obj; ///< If not empty, then expression is
+ ///evaluated in context of this object.
+ ///For details see the comment to
+ ///`UserExpression::Evaluate`.
//----------------------------------------------------------------------
/// The following values should not live beyond parsing
@@ -581,7 +590,7 @@
/// @param[in] type
/// The type that needs to be created.
//------------------------------------------------------------------
- void AddOneType(NameSearchContext &context, TypeFromUser &type,
+ void AddOneType(NameSearchContext &context, const TypeFromUser &type,
unsigned int current_id);
//------------------------------------------------------------------
@@ -594,7 +603,7 @@
/// @param[in] type
/// The type for *this.
//------------------------------------------------------------------
- void AddThisType(NameSearchContext &context, TypeFromUser &type,
+ void AddThisType(NameSearchContext &context, const TypeFromUser &type,
unsigned int current_id);
//------------------------------------------------------------------
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
index e7e9ba9..f967237 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
@@ -59,13 +59,15 @@
ClangUserExpression::ClangUserExpression(
ExecutionContextScope &exe_scope, llvm::StringRef expr,
llvm::StringRef prefix, lldb::LanguageType language,
- ResultType desired_type, const EvaluateExpressionOptions &options)
+ ResultType desired_type, const EvaluateExpressionOptions &options,
+ ValueObject *ctx_obj)
: LLVMUserExpression(exe_scope, expr, prefix, language, desired_type,
options),
m_type_system_helper(*m_target_wp.lock().get(),
options.GetExecutionPolicy() ==
eExecutionPolicyTopLevel),
- m_result_delegate(exe_scope.CalculateTarget()) {
+ m_result_delegate(exe_scope.CalculateTarget()),
+ m_ctx_obj(ctx_obj) {
switch (m_language) {
case lldb::eLanguageTypeC_plus_plus:
m_allow_cxx = true;
@@ -130,7 +132,27 @@
return;
}
- if (clang::CXXMethodDecl *method_decl =
+ if (m_ctx_obj) {
+ switch (m_ctx_obj->GetObjectRuntimeLanguage()) {
+ case lldb::eLanguageTypeC:
+ case lldb::eLanguageTypeC89:
+ case lldb::eLanguageTypeC99:
+ case lldb::eLanguageTypeC11:
+ case lldb::eLanguageTypeC_plus_plus:
+ case lldb::eLanguageTypeC_plus_plus_03:
+ case lldb::eLanguageTypeC_plus_plus_11:
+ case lldb::eLanguageTypeC_plus_plus_14:
+ m_in_cplusplus_method = true;
+ break;
+ case lldb::eLanguageTypeObjC:
+ case lldb::eLanguageTypeObjC_plus_plus:
+ m_in_objectivec_method = true;
+ break;
+ default:
+ break;
+ }
+ m_needs_object_ptr = true;
+ } else if (clang::CXXMethodDecl *method_decl =
ClangASTContext::DeclContextGetAsCXXMethodDecl(decl_context)) {
if (m_allow_cxx && method_decl->isInstance()) {
if (m_enforce_valid_object) {
@@ -396,7 +418,8 @@
m_expr_lang = lldb::eLanguageTypeC;
if (!source_code->GetText(m_transformed_text, m_expr_lang,
- m_in_static_method, exe_ctx)) {
+ m_in_static_method, exe_ctx,
+ !m_ctx_obj)) {
diagnostic_manager.PutString(eDiagnosticSeverityError,
"couldn't construct expression body");
return;
@@ -733,7 +756,15 @@
Status object_ptr_error;
- object_ptr = GetObjectPointer(frame_sp, object_name, object_ptr_error);
+ if (m_ctx_obj) {
+ AddressType address_type;
+ object_ptr = m_ctx_obj->GetAddressOf(false, &address_type);
+ if (object_ptr == LLDB_INVALID_ADDRESS ||
+ address_type != eAddressTypeLoad)
+ object_ptr_error.SetErrorString("Can't get context object's "
+ "debuggee address");
+ } else
+ object_ptr = GetObjectPointer(frame_sp, object_name, object_ptr_error);
if (!object_ptr_error.Success()) {
exe_ctx.GetTargetRef().GetDebugger().GetAsyncOutputStream()->Printf(
@@ -776,9 +807,11 @@
void ClangUserExpression::ClangUserExpressionHelper::ResetDeclMap(
ExecutionContext &exe_ctx,
Materializer::PersistentVariableDelegate &delegate,
- bool keep_result_in_memory) {
+ bool keep_result_in_memory,
+ ValueObject *ctx_obj) {
m_expr_decl_map_up.reset(
- new ClangExpressionDeclMap(keep_result_in_memory, &delegate, exe_ctx));
+ new ClangExpressionDeclMap(keep_result_in_memory, &delegate, exe_ctx,
+ ctx_obj));
}
clang::ASTConsumer *
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.h b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.h
index 836d44e..2f9a723 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.h
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.h
@@ -61,7 +61,8 @@
void ResetDeclMap(ExecutionContext &exe_ctx,
Materializer::PersistentVariableDelegate &result_delegate,
- bool keep_result_in_memory);
+ bool keep_result_in_memory,
+ ValueObject *ctx_obj);
//------------------------------------------------------------------
/// Return the object that the parser should allow to access ASTs. May be
@@ -105,11 +106,17 @@
/// @param[in] desired_type
/// If not eResultTypeAny, the type to use for the expression
/// result.
+ ///
+ /// @param[in] ctx_obj
+ /// The object (if any) in which context the expression
+ /// must be evaluated. For details see the comment to
+ /// `UserExpression::Evaluate`.
//------------------------------------------------------------------
ClangUserExpression(ExecutionContextScope &exe_scope, llvm::StringRef expr,
llvm::StringRef prefix, lldb::LanguageType language,
ResultType desired_type,
- const EvaluateExpressionOptions &options);
+ const EvaluateExpressionOptions &options,
+ ValueObject *ctx_obj);
~ClangUserExpression() override;
@@ -153,7 +160,8 @@
Materializer::PersistentVariableDelegate &result_delegate,
bool keep_result_in_memory) {
m_type_system_helper.ResetDeclMap(exe_ctx, result_delegate,
- keep_result_in_memory);
+ keep_result_in_memory,
+ m_ctx_obj);
}
lldb::ExpressionVariableSP
@@ -204,6 +212,10 @@
/// were not able to calculate this position.
llvm::Optional<size_t> m_user_expression_start_pos;
ResultDelegate m_result_delegate;
+
+ /// The object (if any) in which context the expression is evaluated.
+ /// See the comment to `UserExpression::Evaluate` for details.
+ ValueObject *m_ctx_obj;
};
} // namespace lldb_private
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangUtilityFunction.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangUtilityFunction.cpp
index 210ed3c..c15bfa5 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangUtilityFunction.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangUtilityFunction.cpp
@@ -156,5 +156,6 @@
void ClangUtilityFunction::ClangUtilityFunctionHelper::ResetDeclMap(
ExecutionContext &exe_ctx, bool keep_result_in_memory) {
m_expr_decl_map_up.reset(
- new ClangExpressionDeclMap(keep_result_in_memory, nullptr, exe_ctx));
+ new ClangExpressionDeclMap(keep_result_in_memory, nullptr, exe_ctx,
+ nullptr));
}