From: Alan T. DeKok <aland@freeradius.org>
Date: Thu, 19 May 2022 15:38:07 +0000 (-0400)
Subject: double-check and fix flags.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f588516d8fdc5b89cc1e4b99fb3ab6cacbc2aab0;p=thirdparty%2Ffreeradius-server.git

double-check and fix flags.

We now have a "can_purify" flag.  This is set to "true" for
pure functions which have pure arguments.  And for alternations
which have pure arguments.

%% is set to pure.  XLAT_BOX and XLAT_LITERAL are pure, but
they are not "can_purify".

The result is that we tell if there are portions of the tree
which need additional work for purification.
---

diff --git a/src/lib/unlang/xlat.h b/src/lib/unlang/xlat.h
index 18cd8ea6825..c61773369e8 100644
--- a/src/lib/unlang/xlat.h
+++ b/src/lib/unlang/xlat.h
@@ -106,8 +106,8 @@ typedef struct {
 	bool			needs_resolving;//!< Needs pass2 resolution.
 	bool			needs_async;	//!< Node and all child nodes are guaranteed to not
 						///< require asynchronous expansion.
-	bool			pure;		//!< has no external side effects
-	bool			has_pure_children; //!< as the sticker says
+	bool			pure;		//!< has no external side effects, true for BOX, LITERAL, and some functions
+	bool			can_purify;	//!< if the xlat has a pure function with pure arguments.
 } xlat_flags_t;
 
 /*
diff --git a/src/lib/unlang/xlat_priv.h b/src/lib/unlang/xlat_priv.h
index 67581289bc1..4ce34148576 100644
--- a/src/lib/unlang/xlat_priv.h
+++ b/src/lib/unlang/xlat_priv.h
@@ -178,7 +178,7 @@ static inline CC_HINT(nonnull) void xlat_flags_merge(xlat_flags_t *parent, xlat_
 	parent->needs_resolving |= child->needs_resolving;
 	parent->pure &= child->pure; /* purity can only be removed, never added */
 	parent->pure &= !parent->needs_async; /* things needing async cannot be pure */
-	parent->has_pure_children |= child->pure | child->has_pure_children;
+	parent->can_purify |= child->can_purify;
 }
 
 /** Set the type of an xlat node
diff --git a/src/lib/unlang/xlat_tokenize.c b/src/lib/unlang/xlat_tokenize.c
index a39c7f2e19b..2885cdecdcb 100644
--- a/src/lib/unlang/xlat_tokenize.c
+++ b/src/lib/unlang/xlat_tokenize.c
@@ -128,6 +128,12 @@ xlat_exp_t *xlat_exp_func_alloc(TALLOC_CTX *ctx, xlat_t *func, xlat_exp_head_t c
 	node->flags = func->flags;
 	xlat_flags_merge(&node->flags, &args->flags);
 
+	/*
+	 *	If the function is pure, AND it's arguments are pure,
+	 *	then remember that we need to call a pure function.
+	 */
+	node->flags.can_purify = func->flags.pure && args->flags.pure;
+
 	return node;
 }
 
@@ -175,6 +181,14 @@ static inline int xlat_tokenize_alternation(xlat_exp_head_t *head, fr_sbuff_t *i
 	}
 	node->flags = node->alternate[0]->flags;
 
+	/*
+	 *	If the first argument is pure, then we can purify this
+	 *	node.  If the first argument isn't pure, but the
+	 *	second one is, then we can still purify the second
+	 *	argument.
+	 */
+	node->flags.can_purify |= node->alternate[0]->flags.pure;
+
 	/*
 	 *	Allow the RHS to be empty as a special case.
 	 */
@@ -197,6 +211,7 @@ static inline int xlat_tokenize_alternation(xlat_exp_head_t *head, fr_sbuff_t *i
 		goto error;
 	}
 	xlat_flags_merge(&node->flags, &node->alternate[1]->flags);
+	node->flags.can_purify |= node->alternate[1]->flags.pure;
 
 done:
 	xlat_exp_insert_tail(head, node);
@@ -498,7 +513,11 @@ int xlat_tokenize_function_args(xlat_exp_head_t *head, fr_sbuff_t *in,
 	/*
 	 *	Check we have all the required arguments
 	 */
-	if ((node->type == XLAT_FUNC) && (xlat_validate_function_args(node) < 0)) goto error;
+	if (node->type == XLAT_FUNC) {
+		if (xlat_validate_function_args(node) < 0) goto error;
+
+		node->flags.can_purify = node->call.func->flags.pure && node->call.args->flags.pure;
+	}
 
 	if (!fr_sbuff_next_if_char(in, ')')) {
 		fr_strerror_const("Missing closing brace");
@@ -931,8 +950,11 @@ static int xlat_tokenize_string(xlat_exp_head_t *head,
 			xlat_exp_set_type(node, XLAT_ONE_LETTER);
 			xlat_exp_set_name_buffer_shallow(node, str);
 
-			node->flags.pure = true;	 /* value boxes are always pure */
-			node->flags.needs_async = false; /* value boxes are always non-async */
+			/*
+			 *	%% is pure.  Everything else is not.
+			 */
+			node->flags.pure = (node->fmt[0] == '%');
+			node->flags.needs_async = false;
 
 			xlat_exp_insert_tail(head, node);
 			continue;
@@ -1633,6 +1655,8 @@ int xlat_resolve(xlat_exp_head_t *head, xlat_res_rules_t const *xr_rules)
 			if (xlat_resolve(node->call.args, xr_rules) < 0) return -1;
 			node->flags = node->call.func->flags;
 			xlat_flags_merge(&node->flags, &node->call.args->flags);
+
+			node->flags.can_purify = node->call.func->flags.pure && node->call.args->flags.pure;
 			break;
 
 		/*
@@ -1706,6 +1730,8 @@ int xlat_resolve(xlat_exp_head_t *head, xlat_res_rules_t const *xr_rules)
 			 */
 			xlat_flags_merge(&node->flags, &node->call.args->flags);
 
+			node->flags.can_purify = node->call.func->flags.pure && node->call.args->flags.pure;
+
 			/*
 			 *	Add the freshly resolved function
 			 *	to the bootstrap tree.