kstd/gdb: add error_code and result printers

1 files changed, 51 insertions, 0 deletions

diff --git a/libs/kstd/gdb/result.py b/libs/kstd/gdb/result.py
new file mode 100644
index 00000000..8cef0fed
--- /dev/null
+++ b/libs/kstd/gdb/result.py
@@ -0,0 +1,51 @@
+import gdb
+
+from .error_code import KstdErrorCodePrinter
+
+
+class KstdResultPrinter(gdb.ValuePrinter):
+    def __init__(self, val):
+        self.__val = val
+        self.__has_value = bool(val["_M_has_value"])
+        try:
+            t = val.type.template_argument(0)
+            self.__is_void = t.code == gdb.TYPE_CODE_VOID
+        except (gdb.error, AttributeError):
+            self.__is_void = False
+
+    @property
+    def _error_code(self):
+        return self.__val["_M_unex"]
+
+    @property
+    def _value(self):
+        return self.__val["_M_val"]
+
+    def _format_value(self, gdb_value):
+        printer = gdb.default_visualizer(gdb_value)
+        if printer is not None:
+            return printer.to_string()
+        s = str(gdb_value)
+        if s.startswith("{"):
+            return str(gdb_value.type.strip_typedefs())
+        return s
+
+    def _format_error(self, error_code_val):
+        printer = KstdErrorCodePrinter(error_code_val)
+        return printer.to_string()
+
+    def to_string(self):
+        if not self.__has_value:
+            return f"failure: {self._format_error(self._error_code)}"
+        if self.__is_void:
+            return "success"
+        return f"success: {self._format_value(self._value)}"
+
+    def children(self):
+        if not self.__has_value:
+            yield ("error", self._error_code)
+        elif not self.__is_void:
+            yield ("value", self._value)
+
+    def display_hint(self):
+        return None