GNATCheckWorker: make JSON instances object distinct from diagnostics

This change allows to pass non-critical diagnostics from the worker to
the driver.

Author: thvnx

lkql_checker/src/gnatcheck-compiler.adb

@@ -606,6 +606,19 @@ package body Gnatcheck.Compiler is
             Error (Line (15 .. Line_Len));
             Detected_Internal_Error := @ + 1;
             Errors := True;
+         elsif Line_Len >= 23
+           and then Line (1 .. 23) = "WORKER_JSON_INSTANCES: "
+         then
+            --  Ignore the JSON instances data. This is analyzed in
+            --  Process_LKQL_Rule_File.
+
+            --  The current line can be longer than Line_Len, skip the rest of
+            --  the line if that's the case.
+            if Line_Len = Line'Length then
+               Skip_Line (File);
+            else
+               null;
+            end if;
          else
             Analyze_Line (Line (1 .. Line_Len));
          end if;

lkql_checker/src/gnatcheck-rules-rule_table.adb

@@ -922,6 +922,7 @@ package body Gnatcheck.Rules.Rule_Table is
       Parser_Pid            : Process_Id;
       Waited_Pid            : Process_Id;
       Success               : Boolean;
+      Analyze_Error         : Boolean;
       Config_JSON           : Read_Result;
 
       procedure Rule_Object_Mapper
@@ -952,12 +953,35 @@ package body Gnatcheck.Rules.Rule_Table is
          Error ("can not call the LKQL rule file parser");
          Rule_Option_Problem_Detected := True;
       else
-         Config_JSON := Read (Read_File (JSON_Config_File_Name).all);
+         declare
+            Worker_Output_File : File_Type;
+         begin
+            Open (Worker_Output_File, In_File, JSON_Config_File_Name);
+
+            while not End_Of_File (Worker_Output_File) loop
+               declare
+                  Line : constant String := Get_Line (Worker_Output_File);
+               begin
+                  if Line (1 .. 23) = "WORKER_JSON_INSTANCES: " then
+                     Config_JSON := Read (Line (24 .. Line'Last));
+                     exit;
+                  end if;
+               end;
+            end loop;
+
+            Close (Worker_Output_File);
+         end;
+
+         --  Process diagnostics from worker's output
+         Analyze_Output (JSON_Config_File_Name, Analyze_Error);
 
          --  If the JSON parsing failed, it means that LKQL rule file
-         --  processing failed and diagnostics are in the output file.
-         if not Config_JSON.Success then
-            Analyze_Output (JSON_Config_File_Name, Success);
+         --  processing failed and diagnostics are in the output file and
+         --  they have been already processed.
+         if Analyze_Error
+           or else not Config_JSON.Success
+           or else Config_JSON.Value = JSON_Null
+         then
             Rule_Option_Problem_Detected := True;
 
          --  Else, populate the global rule table with the rule config

lkql_jit/cli/src/main/java/com/adacore/lkql_jit/cli/GNATCheckWorker.java

@@ -209,7 +209,7 @@ protected int executeScript(Context.Builder contextBuilder) {
                         .map(e -> Map.entry(e.getKey(), e.getValue().toJson()))
                         .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))
                 );
-                System.out.println(jsonInstances);
+                System.out.println("WORKER_JSON_INSTANCES: " + jsonInstances);
             } catch (LKQLRuleFileError e) {
                 System.out.println(e.getMessage());
             }