Activate properties traces on a per-property basis

This allows to only activate logging for a subset of properties, which
is generally more useful.

Author: raph-amiard

langkit/expressions/base.py

@@ -2892,7 +2892,8 @@ def __init__(self, expr, prefix, name=None, doc=None, public=None,
                  uses_entity_info=None, uses_envs=None,
                  optional_entity_info=False, warn_on_unused=True,
                  ignore_warn_on_node=None,
-                 call_non_memoizable_because=None):
+                 call_non_memoizable_because=None,
+                 activate_tracing=False):
         """
         :param expr: The expression for the property. It can be either:
             * An expression.
@@ -2995,6 +2996,9 @@ def __init__(self, expr, prefix, name=None, doc=None, public=None,
             of this property in a memoized context impossible. Must be used for
             external properties that do side effects (such as loading an
             analysis unit), as this conflicts with the memoization machinery.
+
+        :param bool activate_tracing: Whether we want to activate tracing for
+            this property's execution.
         """
 
         self.prefix = prefix
@@ -3153,6 +3157,8 @@ def __init__(self, expr, prefix, name=None, doc=None, public=None,
         variable.
         """
 
+        self.activate_tracing = activate_tracing
+
     @property
     def has_debug_info(self):
         """
@@ -4134,7 +4140,8 @@ def langkit_property(public=None, return_type=None, kind=AbstractKind.concrete,
                      call_memoizable=False, memoize_in_populate=False,
                      external=False, uses_entity_info=None, uses_envs=None,
                      warn_on_unused=True, ignore_warn_on_node=None,
-                     call_non_memoizable_because=None):
+                     call_non_memoizable_because=None,
+                     activate_tracing=False):
     """
     Decorator to create properties from real Python methods. See Property for
     more details.
@@ -4162,6 +4169,7 @@ def decorator(expr_fn):
             warn_on_unused=warn_on_unused,
             ignore_warn_on_node=ignore_warn_on_node,
             call_non_memoizable_because=call_non_memoizable_because,
+            activate_tracing=activate_tracing,
         )
     return decorator
 

langkit/templates/pkg_implementation_spec_ada.mako

@@ -288,7 +288,10 @@ private package ${ada_lib_name}.Implementation is
    function "+" (Left, Right : Big_Integer_Type) return Big_Integer_Type;
    function "-" (Left, Right : Big_Integer_Type) return Big_Integer_Type;
 
+   % if ctx.properties_logging:
    function Trace_Image (I : Big_Integer_Type) return String;
+   % endif
+
    ------------------------------------------------------
    -- AST node derived types (incomplete declarations) --
    ------------------------------------------------------

langkit/templates/properties/def_ada.mako

@@ -85,7 +85,7 @@ is
 begin
    ${gdb_property_body_start()}
 
-   % if ctx.properties_logging:
+   % if has_logging:
       Properties_Traces.Trace
         ("${property.qualname} ("
         % if property._has_self_entity:
@@ -147,15 +147,15 @@ begin
             Mmz_Val := Memoization_Maps.Element (Mmz_Cur);
 
             if Mmz_Val.Kind = Mmz_Evaluating then
-               % if ctx.properties_logging:
+               % if has_logging:
                   Properties_Traces.Trace
                     ("Result: infinite recursion");
                % endif
                ${gdb_memoization_return()}
                raise Property_Error with "Infinite recursion detected";
 
             elsif Mmz_Val.Kind = Mmz_Property_Error then
-               % if ctx.properties_logging:
+               % if has_logging:
                   Properties_Traces.Trace
                     ("Result: Property_Error");
                   Properties_Traces.Decrease_Indent;
@@ -169,7 +169,7 @@ begin
                   Inc_Ref (Property_Result);
                % endif
 
-               % if ctx.properties_logging:
+               % if has_logging:
                   Properties_Traces.Trace
                     ("Result: " & Trace_Image (Property_Result));
                   Properties_Traces.Decrease_Indent;
@@ -212,7 +212,7 @@ begin
       % endif
    % endif
 
-   % if ctx.properties_logging:
+   % if has_logging:
       Properties_Traces.Trace ("Result: " & Trace_Image (Property_Result));
       Properties_Traces.Decrease_Indent;
    % endif
@@ -221,7 +221,7 @@ begin
 
 % if property.vars.root_scope.has_refcounted_vars(True) or \
      property.memoized or \
-     ctx.properties_logging:
+     has_logging:
    exception
       when Property_Error =>
          % for scope in all_scopes:
@@ -242,7 +242,7 @@ begin
             % endif
          % endif
 
-         % if ctx.properties_logging:
+         % if has_logging:
             Properties_Traces.Trace ("Result: Properties_Error");
             Properties_Traces.Decrease_Indent;
          % endif