Merge branch 'topic/minor-pp-cleanups' into 'master'

Minor gdb pretty-printer cleanups

See merge request eng/ide/VSS!349

gdb/vss_pp.py

@@ -1,5 +1,13 @@
+import gdb
+import gdb.printing
 from gnatdbg.tagged import reinterpret_tagged
 
+# Use the tag class if it is available.
+if hasattr(gdb, "ValuePrinter"):
+    base = gdb.ValuePrinter
+else:
+    base = object
+
 
 def decode_utf8(bytes, size):
     result = ""
@@ -36,9 +44,9 @@ def decode_utf8(bytes, size):
     return result
 
 
-class Virtual_String_Printer:
+class Virtual_String_Printer(base):
     def __init__(self, val):
-        self.val = val
+        self._val = val
 
     def to_string(self):
         text_type = gdb.lookup_type(
@@ -51,7 +59,7 @@ def to_string(self):
             "vss.implementation.text_handlers.utf8.dynamic.dynamic_utf8_handler"
         )
 
-        storage = self.val["data"]["storage"]
+        storage = self._val["data"]["storage"]
 
         if all(byte == 0 for byte in storage.bytes):
             # "null" string
@@ -72,7 +80,7 @@ def to_string(self):
             return decode_utf8(data["storage"].bytes, data["size"])
 
         else:
-            print("<UNKNOWN TYPE>")
+            raise TypeError("<UNKNOWN TYPE>")
 
         return None
 
@@ -81,9 +89,15 @@ def to_string(self):
 #        return "string"
 
 
-def vss_pp_func(val):
-    if str(val.type) == "vss.strings.virtual_string":
-        return Virtual_String_Printer(val)
+class VSSPrinter(gdb.printing.PrettyPrinter):
+    """Pretty-print VSS strings."""
+
+    def __init__(self):
+        super().__init__("VSS")
+
+    def __call__(self, val):
+        if str(val.type) == "vss.strings.virtual_string":
+            return Virtual_String_Printer(val)
 
 
-gdb.pretty_printers.append(vss_pp_func)
+gdb.printing.register_pretty_printer(None, VSSPrinter())