ENT-13295: Added evaluation order option in body agent control

cf-agent/cf-agent.c

@@ -1002,12 +1002,6 @@ static void KeepControlPromises(EvalContext *ctx, const Policy *policy, GenericA
                 continue;
             }
 
-            if (CommonControlFromString(cp->lval) != COMMON_CONTROL_MAX)
-            {
-                /* Already handled in generic_agent */
-                continue;
-            }
-
             VarRef *ref = VarRefParseFromScope(cp->lval, "control_agent");
             DataType value_type;
             const void *value = EvalContextVariableGet(ctx, ref, &value_type);
@@ -1353,6 +1347,22 @@ static void KeepControlPromises(EvalContext *ctx, const Policy *policy, GenericA
                     config->agent_specific.agent.report_class_log? "true" : "false");
                 continue;
             }
+
+            if (StringEqual(cp->lval, CFA_CONTROLBODY[AGENT_CONTROL_EVALUATION_ORDER].lval))
+            {
+                assert(value_type == CF_DATA_TYPE_STRING);
+                const char *evaluation_order = (char *) value;
+                Log(LOG_LEVEL_VERBOSE, "SET evaluation %s", evaluation_order);
+
+                if (StringEqual(evaluation_order, "top_down"))
+                {
+                    EvalContextSetAgentEvalOrder(ctx, EVAL_ORDER_TOP_DOWN);
+                }
+                else
+                {
+                    EvalContextSetAgentEvalOrder(ctx, EVAL_ORDER_CLASSIC);
+                }
+            }
         }
     }
 
@@ -1569,7 +1579,7 @@ static void AllClassesReport(const EvalContext *ctx)
 PromiseResult ScheduleAgentOperations(EvalContext *ctx, const Bundle *bp)
 // NB - this function can be called recursively through "methods"
 {
-    if (EvalContextGetEvalOption(ctx, EVAL_OPTION_CLASSIC_EVALUATION))
+    if (EvalContextIsClassicOrder(ctx))
     {
         return ScheduleAgentOperationsNormalOrder(ctx, bp);
     }

libpromises/cf3.defs.h

@@ -495,6 +495,7 @@ typedef enum
     AGENT_CONTROL_REPORTCLASSLOG,
     AGENT_CONTROL_SELECT_END_MATCH_EOF,
     AGENT_CONTROL_COPYFROM_RESTRICT_KEYS,
+    AGENT_CONTROL_EVALUATION_ORDER,
     AGENT_CONTROL_NONE
 } AgentControl;
 

libpromises/eval_context.c

@@ -206,6 +206,9 @@ struct EvalContext_
         int64_t elapsed;
         Seq *events;
     } profiler;
+
+    EvalContextEvalOrder common_eval_order;
+    EvalContextEvalOrder agent_eval_order;
 };
 
 void EvalContextSetConfig(EvalContext *ctx, const GenericAgentConfig *config)
@@ -1110,6 +1113,10 @@ EvalContext *EvalContextNew(void)
     ctx->profiler.events = SeqNew(20, EventFrameDestroy);
     ctx->profiler.elapsed = 0;
 
+    // evaluation order
+    ctx->common_eval_order = EVAL_ORDER_UNDEFINED;
+    ctx->agent_eval_order = EVAL_ORDER_UNDEFINED;
+
     return ctx;
 }
 
@@ -4047,3 +4054,39 @@ void EvalContextProfilingEnd(EvalContext *ctx, const Policy *policy)
 
     JsonDestroy(profiling);
 }
+
+// ##############################################################
+
+void EvalContextSetCommonEvalOrder(EvalContext *ctx, EvalContextEvalOrder eval_order)
+{
+    assert(ctx != NULL);
+    ctx->common_eval_order = eval_order;
+}
+
+void EvalContextSetAgentEvalOrder(EvalContext *ctx, EvalContextEvalOrder eval_order)
+{
+    assert(ctx != NULL);
+    ctx->agent_eval_order = eval_order;
+}
+
+bool EvalContextIsClassicOrder(EvalContext *ctx)
+{
+    assert(ctx != NULL);
+
+    if (ctx->config->agent_type != AGENT_TYPE_AGENT)
+    {
+        // Not cf-agent, so we ignore body agent control
+        return (ctx->common_eval_order != EVAL_ORDER_TOP_DOWN);
+    }
+
+    // cf-agent
+    if (ctx->agent_eval_order != EVAL_ORDER_UNDEFINED)
+    {
+        // evaluation_order from body agent control has priority, if defined
+        return (ctx->agent_eval_order == EVAL_ORDER_CLASSIC);
+    }
+
+    // The fallback is to use what is defined in body common control,
+    // or if not defined there either, default to true (normal order)
+    return (ctx->common_eval_order != EVAL_ORDER_TOP_DOWN);
+}

libpromises/eval_context.h

@@ -120,11 +120,17 @@ typedef enum
 
     EVAL_OPTION_EVAL_FUNCTIONS = 1 << 0,
     EVAL_OPTION_CACHE_SYSTEM_FUNCTIONS = 1 << 1,
-    EVAL_OPTION_CLASSIC_EVALUATION = 1 << 2,
 
     EVAL_OPTION_FULL = 0xFFFFFFFF
 } EvalContextOption;
 
+typedef enum
+{
+    EVAL_ORDER_UNDEFINED = 0,
+    EVAL_ORDER_CLASSIC,
+    EVAL_ORDER_TOP_DOWN
+} EvalContextEvalOrder;
+
 EvalContext *EvalContextNew(void);
 void EvalContextDestroy(EvalContext *ctx);
 
@@ -453,4 +459,8 @@ void EvalContextSetProfiling(EvalContext *ctx, bool profiling);
 void EvalContextProfilingStart(EvalContext *ctx);
 void EvalContextProfilingEnd(EvalContext *ctx, const Policy *policy);
 
+void EvalContextSetCommonEvalOrder(EvalContext *ctx, EvalContextEvalOrder eval_order);
+void EvalContextSetAgentEvalOrder(EvalContext *ctx, EvalContextEvalOrder eval_order);
+bool EvalContextIsClassicOrder(EvalContext *ctx);
+
 #endif

libpromises/expand.c

@@ -1030,8 +1030,14 @@ static void ResolveControlBody(EvalContext *ctx, GenericAgentConfig *config,
             Log(LOG_LEVEL_VERBOSE, "SET evaluation %s",
                 RvalScalarValue(evaluated_rval));
 
-            bool is_classic = (StringEqual(RvalScalarValue(evaluated_rval), "classic"));
-            EvalContextSetEvalOption(ctx, EVAL_OPTION_CLASSIC_EVALUATION, is_classic);
+            if (StringEqual(RvalScalarValue(evaluated_rval), "top_down"))
+            {
+                EvalContextSetCommonEvalOrder(ctx, EVAL_ORDER_TOP_DOWN);
+            }
+            else
+            {
+                EvalContextSetCommonEvalOrder(ctx, EVAL_ORDER_CLASSIC);
+            }
         }
 
         RvalDestroy(evaluated_rval);

libpromises/mod_common.c

@@ -320,6 +320,7 @@ const ConstraintSyntax CFA_CONTROLBODY[] =
     ConstraintSyntaxNewBool("report_class_log", "true/false enables logging classes at the end of agent execution. Default value: false", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewBool("select_end_match_eof", "Set the default behavior of select_end_match_eof in edit_line promises. Default: false", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewStringList("copyfrom_restrict_keys", ".*", "A list of key hashes to restrict copy_from to", SYNTAX_STATUS_NORMAL),
+    ConstraintSyntaxNewString("evaluation_order", "(classic|top_down)", "Order of evaluation of promises of agent", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewNull()
 };