[lldb/Interpreter] Add requirements to Scripted Interface abstract methods

medismailben · medismailben · commit 897dd358d3b1 · 2024-09-19T13:25:06.000-07:00
This patch adds new requirements to the Scripted Interface abstract
method checker to check the minimum number of argument for abstract
methods.

This check is done when creating the interface object so the object is
not created if the user implementation doesn't match the abstract method
requirement.

Signed-off-by: Med Ismail Bennani &lt;ismail@bennani.ma&gt;
diff --git a/lldb/include/lldb/Interpreter/Interfaces/ScriptedInterface.h b/lldb/include/lldb/Interpreter/Interfaces/ScriptedInterface.h
@@ -31,7 +31,22 @@ class ScriptedInterface {
     return m_object_instance_sp;
   }
 
-  virtual llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const = 0;
+  struct AbstractMethodRequirement {
+    llvm::StringLiteral name;
+    size_t min_arg_count = 0;
+  };
+
+  virtual llvm::SmallVector<AbstractMethodRequirement>
+  GetAbstractMethodRequirements() const = 0;
+
+  llvm::SmallVector<llvm::StringLiteral> const GetAbstractMethods() const {
+    llvm::SmallVector<llvm::StringLiteral> abstract_methods;
+    llvm::transform(GetAbstractMethodRequirements(), abstract_methods.begin(),
+                    [](const AbstractMethodRequirement &requirement) {
+                      return requirement.name;
+                    });
+    return abstract_methods;
+  }
 
   template <typename Ret>
   static Ret ErrorWithMessage(llvm::StringRef caller_name,
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/OperatingSystemPythonInterface.h b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/OperatingSystemPythonInterface.h
@@ -31,8 +31,9 @@ class OperatingSystemPythonInterface
                      StructuredData::DictionarySP args_sp,
                      StructuredData::Generic *script_obj = nullptr) override;
 
-  llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const override {
-    return llvm::SmallVector<llvm::StringLiteral>({"get_thread_info"});
+  llvm::SmallVector<AbstractMethodRequirement>
+  GetAbstractMethodRequirements() const override {
+    return llvm::SmallVector<AbstractMethodRequirement>({{"get_thread_info"}});
   }
 
   StructuredData::DictionarySP CreateThread(lldb::tid_t tid,
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPlatformPythonInterface.h b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPlatformPythonInterface.h
@@ -29,10 +29,13 @@ class ScriptedPlatformPythonInterface : public ScriptedPlatformInterface,
                      StructuredData::DictionarySP args_sp,
                      StructuredData::Generic *script_obj = nullptr) override;
 
-  llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const override {
-    return llvm::SmallVector<llvm::StringLiteral>(
-        {"list_processes", "attach_to_process", "launch_process",
-         "kill_process"});
+  llvm::SmallVector<AbstractMethodRequirement>
+  GetAbstractMethodRequirements() const override {
+    return llvm::SmallVector<AbstractMethodRequirement>(
+        {{"list_processes"},
+         {"attach_to_process", 2},
+         {"launch_process", 2},
+         {"kill_process", 2}});
   }
 
   StructuredData::DictionarySP ListProcesses() override;
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedProcessPythonInterface.h b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedProcessPythonInterface.h
@@ -31,9 +31,12 @@ class ScriptedProcessPythonInterface : public ScriptedProcessInterface,
                      StructuredData::DictionarySP args_sp,
                      StructuredData::Generic *script_obj = nullptr) override;
 
-  llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const override {
-    return llvm::SmallVector<llvm::StringLiteral>(
-        {"read_memory_at_address", "is_alive", "get_scripted_thread_plugin"});
+  llvm::SmallVector<AbstractMethodRequirement>
+  GetAbstractMethodRequirements() const override {
+    return llvm::SmallVector<AbstractMethodRequirement>(
+        {{"read_memory_at_address", 4},
+         {"is_alive"},
+         {"get_scripted_thread_plugin"}});
   }
 
   StructuredData::DictionarySP GetCapabilities() override;
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPythonInterface.h b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPythonInterface.h
@@ -36,37 +36,78 @@ class ScriptedPythonInterface : virtual public ScriptedInterface {
     eNotImplemented,
     eNotAllocated,
     eNotCallable,
+    eUnknownArgumentCount,
+    eInvalidArgumentCount,
     eValid
   };
 
-  llvm::Expected<std::map<llvm::StringLiteral, AbstractMethodCheckerCases>>
+  struct AbstrackMethodCheckerPayload {
+
+    struct InvalidArgumentCountPayload {
+      InvalidArgumentCountPayload(size_t required, size_t actual)
+          : required_argument_count(required), actual_argument_count(actual) {}
+
+      size_t required_argument_count;
+      size_t actual_argument_count;
+    };
+
+    AbstractMethodCheckerCases checker_case;
+    std::variant<std::monostate, InvalidArgumentCountPayload> payload;
+  };
+
+  llvm::Expected<std::map<llvm::StringLiteral, AbstrackMethodCheckerPayload>>
   CheckAbstractMethodImplementation(
       const python::PythonDictionary &class_dict) const {
 
     using namespace python;
 
-    std::map<llvm::StringLiteral, AbstractMethodCheckerCases> checker;
-#define SET_ERROR_AND_CONTINUE(method_name, error)                             \
+    std::map<llvm::StringLiteral, AbstrackMethodCheckerPayload> checker;
+#define SET_CASE_AND_CONTINUE(method_name, case)                               \
   {                                                                            \
-    checker[method_name] = error;                                              \
+    checker[method_name] = {case, {}};                                         \
     continue;                                                                  \
   }
 
-    for (const llvm::StringLiteral &method_name : GetAbstractMethods()) {
+    for (const AbstractMethodRequirement &requirement :
+         GetAbstractMethodRequirements()) {
+      llvm::StringLiteral method_name = requirement.name;
       if (!class_dict.HasKey(method_name))
-        SET_ERROR_AND_CONTINUE(method_name,
-                               AbstractMethodCheckerCases::eNotImplemented)
+        SET_CASE_AND_CONTINUE(method_name,
+                              AbstractMethodCheckerCases::eNotImplemented)
       auto callable_or_err = class_dict.GetItem(method_name);
-      if (!callable_or_err)
-        SET_ERROR_AND_CONTINUE(method_name,
-                               AbstractMethodCheckerCases::eNotAllocated)
-      if (!PythonCallable::Check(callable_or_err.get().get()))
-        SET_ERROR_AND_CONTINUE(method_name,
-                               AbstractMethodCheckerCases::eNotCallable)
-      checker[method_name] = AbstractMethodCheckerCases::eValid;
+      if (!callable_or_err) {
+        llvm::consumeError(callable_or_err.takeError());
+        SET_CASE_AND_CONTINUE(method_name,
+                              AbstractMethodCheckerCases::eNotAllocated)
+      }
+
+      PythonCallable callable = callable_or_err->AsType<PythonCallable>();
+      if (!callable)
+        SET_CASE_AND_CONTINUE(method_name,
+                              AbstractMethodCheckerCases::eNotCallable)
+
+      if (!requirement.min_arg_count)
+        SET_CASE_AND_CONTINUE(method_name, AbstractMethodCheckerCases::eValid)
+
+      auto arg_info_or_err = callable.GetArgInfo();
+      if (!arg_info_or_err) {
+        llvm::consumeError(arg_info_or_err.takeError());
+        SET_CASE_AND_CONTINUE(method_name,
+                              AbstractMethodCheckerCases::eUnknownArgumentCount)
+      }
+
+      PythonCallable::ArgInfo arg_info = *arg_info_or_err;
+      if (requirement.min_arg_count <= arg_info.max_positional_args) {
+        SET_CASE_AND_CONTINUE(method_name, AbstractMethodCheckerCases::eValid)
+      } else {
+        checker[method_name] = {
+            AbstractMethodCheckerCases::eInvalidArgumentCount,
+            AbstrackMethodCheckerPayload::InvalidArgumentCountPayload(
+                requirement.min_arg_count, arg_info.max_positional_args)};
+      }
     }
 
-#undef HANDLE_ERROR
+#undef SET_CASE_AND_CONTINUE
 
     return checker;
   }
@@ -78,8 +119,11 @@ class ScriptedPythonInterface : virtual public ScriptedInterface {
     using namespace python;
     using Locker = ScriptInterpreterPythonImpl::Locker;
 
-    auto create_error = [](std::string message) {
-      return llvm::createStringError(llvm::inconvertibleErrorCode(), message);
+    Log *log = GetLog(LLDBLog::Script);
+    auto create_error = [](llvm::StringLiteral format, auto &&...ts) {
+      return llvm::createStringError(
+          llvm::formatv(format.data(), std::forward<decltype(ts)>(ts)...)
+              .str());
     };
 
     bool has_class_name = !class_name.empty();
@@ -107,16 +151,15 @@ class ScriptedPythonInterface : virtual public ScriptedInterface {
           PythonModule::MainModule().ResolveName<python::PythonDictionary>(
               m_interpreter.GetDictionaryName());
       if (!dict.IsAllocated())
-        return create_error(
-            llvm::formatv("Could not find interpreter dictionary: %s",
-                          m_interpreter.GetDictionaryName()));
+        return create_error("Could not find interpreter dictionary: {0}",
+                            m_interpreter.GetDictionaryName());
 
       auto init =
           PythonObject::ResolveNameWithDictionary<python::PythonCallable>(
               class_name, dict);
       if (!init.IsAllocated())
-        return create_error(llvm::formatv("Could not find script class: {0}",
-                                          class_name.data()));
+        return create_error("Could not find script class: {0}",
+                            class_name.data());
 
       std::tuple<Args...> original_args = std::forward_as_tuple(args...);
       auto transformed_args = TransformArgs(original_args);
@@ -186,36 +229,73 @@ class ScriptedPythonInterface : virtual public ScriptedInterface {
     if (!checker_or_err)
       return checker_or_err.takeError();
 
+    llvm::Error abstract_method_errors = llvm::Error::success();
     for (const auto &method_checker : *checker_or_err)
-      switch (method_checker.second) {
+      switch (method_checker.second.checker_case) {
       case AbstractMethodCheckerCases::eNotImplemented:
-        LLDB_LOG(GetLog(LLDBLog::Script),
-                 "Abstract method {0}.{1} not implemented.",
-                 obj_class_name.GetString(), method_checker.first);
+        abstract_method_errors = llvm::joinErrors(
+            std::move(abstract_method_errors),
+            std::move(create_error("Abstract method {0}.{1} not implemented.",
+                                   obj_class_name.GetString(),
+                                   method_checker.first)));
         break;
       case AbstractMethodCheckerCases::eNotAllocated:
-        LLDB_LOG(GetLog(LLDBLog::Script),
-                 "Abstract method {0}.{1} not allocated.",
-                 obj_class_name.GetString(), method_checker.first);
+        abstract_method_errors = llvm::joinErrors(
+            std::move(abstract_method_errors),
+            std::move(create_error("Abstract method {0}.{1} not allocated.",
+                                   obj_class_name.GetString(),
+                                   method_checker.first)));
         break;
       case AbstractMethodCheckerCases::eNotCallable:
-        LLDB_LOG(GetLog(LLDBLog::Script),
-                 "Abstract method {0}.{1} not callable.",
-                 obj_class_name.GetString(), method_checker.first);
+        abstract_method_errors = llvm::joinErrors(
+            std::move(abstract_method_errors),
+            std::move(create_error("Abstract method {0}.{1} not callable.",
+                                   obj_class_name.GetString(),
+                                   method_checker.first)));
+        break;
+      case AbstractMethodCheckerCases::eUnknownArgumentCount:
+        abstract_method_errors = llvm::joinErrors(
+            std::move(abstract_method_errors),
+            std::move(create_error(
+                "Abstract method {0}.{1} has unknown argument count.",
+                obj_class_name.GetString(), method_checker.first)));
         break;
+      case AbstractMethodCheckerCases::eInvalidArgumentCount: {
+        auto &payload_variant = method_checker.second.payload;
+        if (!std::holds_alternative<
+                AbstrackMethodCheckerPayload::InvalidArgumentCountPayload>(
+                payload_variant)) {
+          abstract_method_errors = llvm::joinErrors(
+              std::move(abstract_method_errors),
+              std::move(create_error(
+                  "Abstract method {0}.{1} has unexpected argument count.",
+                  obj_class_name.GetString(), method_checker.first)));
+        } else {
+          auto payload = std::get<
+              AbstrackMethodCheckerPayload::InvalidArgumentCountPayload>(
+              payload_variant);
+          abstract_method_errors = llvm::joinErrors(
+              std::move(abstract_method_errors),
+              std::move(
+                  create_error("Abstract method {0}.{1} has unexpected "
+                               "argument count (expected {2} but has {3}).",
+                               obj_class_name.GetString(), method_checker.first,
+                               payload.required_argument_count,
+                               payload.actual_argument_count)));
+        }
+      } break;
       case AbstractMethodCheckerCases::eValid:
-        LLDB_LOG(GetLog(LLDBLog::Script),
-                 "Abstract method {0}.{1} implemented & valid.",
+        LLDB_LOG(log, "Abstract method {0}.{1} implemented & valid.",
                  obj_class_name.GetString(), method_checker.first);
         break;
       }
 
-    for (const auto &method_checker : *checker_or_err)
-      if (method_checker.second != AbstractMethodCheckerCases::eValid)
-        return create_error(
-            llvm::formatv("Abstract method {0}.{1} missing. Enable lldb "
-                          "script log for more details.",
-                          obj_class_name.GetString(), method_checker.first));
+    if (abstract_method_errors) {
+      Status error = Status::FromError(std::move(abstract_method_errors));
+      LLDB_LOG(log, "Abstract method error in {0}:\n{1}", class_name,
+               error.AsCString());
+      return error.ToError();
+    }
 
     m_object_instance_sp = StructuredData::GenericSP(
         new StructuredPythonObject(std::move(result)));
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedThreadPlanPythonInterface.h b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedThreadPlanPythonInterface.h
@@ -30,7 +30,8 @@ class ScriptedThreadPlanPythonInterface : public ScriptedThreadPlanInterface,
                      lldb::ThreadPlanSP thread_plan_sp,
                      const StructuredDataImpl &args_sp) override;
 
-  llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const override {
+  llvm::SmallVector<AbstractMethodRequirement>
+  GetAbstractMethodRequirements() const override {
     return {};
   }
 
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedThreadPythonInterface.h b/lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedThreadPythonInterface.h
@@ -28,9 +28,10 @@ class ScriptedThreadPythonInterface : public ScriptedThreadInterface,
                      StructuredData::DictionarySP args_sp,
                      StructuredData::Generic *script_obj = nullptr) override;
 
-  llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const override {
-    return llvm::SmallVector<llvm::StringLiteral>(
-        {"get_stop_reason", "get_register_context"});
+  llvm::SmallVector<AbstractMethodRequirement>
+  GetAbstractMethodRequirements() const override {
+    return llvm::SmallVector<AbstractMethodRequirement>(
+        {{"get_stop_reason"}, {"get_register_context"}});
   }
 
   lldb::tid_t GetThreadID() override;

Original file line number	Diff line number	Diff line change
`@@ -30,7 +30,8 @@ class ScriptedThreadPlanPythonInterface : public ScriptedThreadPlanInterface,`
`30`	`30`	`lldb::ThreadPlanSP thread_plan_sp,`
`31`	`31`	`const StructuredDataImpl &args_sp) override;`
`32`	`32`
`33`		`- llvm::SmallVector<llvm::StringLiteral> GetAbstractMethods() const override {`
	`33`	`+ llvm::SmallVector<AbstractMethodRequirement>`
	`34`	`+ GetAbstractMethodRequirements() const override {`
`34`	`35`	`return {};`
`35`	`36`	`}`
`36`	`37`