[lldb] Do not narrow GetIndexOfChildWithName return type to int (#165453)

Modify the python wrapper to return uint32_t,
which prevents incorrect child name-to-index mapping and avoids
performing redundant operations on non-existent SBValues.

Author: da-viper

lldb/bindings/python/python-wrapper.swig

@@ -312,7 +312,7 @@ PyObject *lldb_private::python::SWIGBridge::LLDBSwigPython_GetChildAtIndex(PyObj
   return result.release();
 }
 
-int lldb_private::python::SWIGBridge::LLDBSwigPython_GetIndexOfChildWithName(
+uint32_t lldb_private::python::SWIGBridge::LLDBSwigPython_GetIndexOfChildWithName(
     PyObject * implementor, const char *child_name) {
   PyErr_Cleaner py_err_cleaner(true);
 

lldb/include/lldb/Interpreter/ScriptInterpreter.h

@@ -352,7 +352,7 @@ class ScriptInterpreter : public PluginInterface {
     return lldb::ValueObjectSP();
   }
 
-  virtual llvm::Expected<int>
+  virtual llvm::Expected<uint32_t>
   GetIndexOfChildWithName(const StructuredData::ObjectSP &implementor,
                           const char *child_name) {
     return llvm::createStringError("Type has no child named '%s'", child_name);

lldb/source/Plugins/ScriptInterpreter/Python/SWIGPythonBridge.h

@@ -158,8 +158,9 @@ class SWIGBridge {
   static PyObject *LLDBSwigPython_GetChildAtIndex(PyObject *implementor,
                                                   uint32_t idx);
 
-  static int LLDBSwigPython_GetIndexOfChildWithName(PyObject *implementor,
-                                                    const char *child_name);
+  static uint32_t
+  LLDBSwigPython_GetIndexOfChildWithName(PyObject *implementor,
+                                         const char *child_name);
 
   static lldb::ValueObjectSP
   LLDBSWIGPython_GetValueObjectSPFromSBValue(void *data);

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp

@@ -1939,7 +1939,7 @@ lldb::ValueObjectSP ScriptInterpreterPythonImpl::GetChildAtIndex(
   return ret_val;
 }
 
-llvm::Expected<int> ScriptInterpreterPythonImpl::GetIndexOfChildWithName(
+llvm::Expected<uint32_t> ScriptInterpreterPythonImpl::GetIndexOfChildWithName(
     const StructuredData::ObjectSP &implementor_sp, const char *child_name) {
   if (!implementor_sp)
     return llvm::createStringError("Type has no child named '%s'", child_name);
@@ -1951,7 +1951,7 @@ llvm::Expected<int> ScriptInterpreterPythonImpl::GetIndexOfChildWithName(
   if (!implementor)
     return llvm::createStringError("Type has no child named '%s'", child_name);
 
-  int ret_val = INT32_MAX;
+  uint32_t ret_val = UINT32_MAX;
 
   {
     Locker py_lock(this,
@@ -1960,7 +1960,7 @@ llvm::Expected<int> ScriptInterpreterPythonImpl::GetIndexOfChildWithName(
                                                                  child_name);
   }
 
-  if (ret_val == INT32_MAX)
+  if (ret_val == UINT32_MAX)
     return llvm::createStringError("Type has no child named '%s'", child_name);
   return ret_val;
 }

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h

@@ -122,7 +122,7 @@ class ScriptInterpreterPythonImpl : public ScriptInterpreterPython {
   GetChildAtIndex(const StructuredData::ObjectSP &implementor,
                   uint32_t idx) override;
 
-  llvm::Expected<int>
+  llvm::Expected<uint32_t>
   GetIndexOfChildWithName(const StructuredData::ObjectSP &implementor,
                           const char *child_name) override;
 

lldb/unittests/ScriptInterpreter/Python/PythonTestSuite.cpp

@@ -90,7 +90,8 @@ PyObject *lldb_private::python::SWIGBridge::LLDBSwigPython_GetChildAtIndex(
   return nullptr;
 }
 
-int lldb_private::python::SWIGBridge::LLDBSwigPython_GetIndexOfChildWithName(
+uint32_t
+lldb_private::python::SWIGBridge::LLDBSwigPython_GetIndexOfChildWithName(
     PyObject *implementor, const char *child_name) {
   return 0;
 }