From: Alan T. DeKok <aland@freeradius.org>
Date: Sun, 1 Sep 2024 13:38:35 +0000 (-0400)
Subject: track impure functions separately from pure xlats
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=53a2a1547ac4f854958a96309a8525519ea73539;p=thirdparty%2Ffreeradius-server.git

track impure functions separately from pure xlats

which means that

	&foo - 1

isn't pure, because it depends on "foo".  But it's also not an
impure function, which means it can be calculated without the
interpreter yielding
---

diff --git a/src/lib/unlang/xlat.h b/src/lib/unlang/xlat.h
index 797c44634f..48fc8a45a4 100644
--- a/src/lib/unlang/xlat.h
+++ b/src/lib/unlang/xlat.h
@@ -110,6 +110,7 @@ typedef struct xlat_s xlat_t;
 typedef struct {
 	bool			needs_resolving;//!< Needs pass2 resolution.
 	bool			pure;		//!< has no external side effects, true for BOX, LITERAL, and some functions
+	bool			impure_func;	//!< xlat contains an impure function
 	bool			can_purify;	//!< if the xlat has a pure function with pure arguments.
 
 	bool			constant;	//!< xlat is just tmpl_attr_tail_data, or XLAT_BOX
@@ -435,6 +436,8 @@ tmpl_t		*xlat_to_tmpl_attr(TALLOC_CTX *ctx, xlat_exp_head_t *xlat);
 
 int		xlat_from_tmpl_attr(TALLOC_CTX *ctx, xlat_exp_head_t **head, tmpl_t **vpt_p);
 
+bool		xlat_impure_func(xlat_exp_head_t const *head) CC_HINT(nonnull);
+
 /*
  *	xlat_alloc.c
  */
diff --git a/src/lib/unlang/xlat_expr.c b/src/lib/unlang/xlat_expr.c
index 8fa41a0503..26cb49fb02 100644
--- a/src/lib/unlang/xlat_expr.c
+++ b/src/lib/unlang/xlat_expr.c
@@ -2153,6 +2153,7 @@ static fr_slen_t tokenize_unary(xlat_exp_head_t *head, xlat_exp_t **out, fr_sbuf
 	unary->call.func = func;
 	unary->call.dict = t_rules->attr.dict_def;
 	unary->flags = func->flags;
+	unary->flags.impure_func = !func->flags.pure;
 
 	if (tokenize_field(unary->call.args, &node, &our_in, p_rules, t_rules, bracket_rules, out_c, (c == '!')) < 0) {
 		talloc_free(unary);
@@ -2374,7 +2375,7 @@ static fr_slen_t tokenize_rcode(xlat_exp_head_t *head, xlat_exp_t **out, fr_sbuf
 	MEM(node = xlat_exp_alloc(head, XLAT_FUNC, fr_sbuff_start(&our_in), slen));
 	node->call.func = func;
 	// no need to set dict here
-	node->flags = func->flags;
+	node->flags = func->flags; /* rcode is impure, but can be calculated statically */
 
 	MEM(arg = xlat_exp_alloc(node, XLAT_BOX, fr_sbuff_start(&our_in), slen));
 
@@ -2982,6 +2983,7 @@ redo:
 	node->call.func = func;
 	node->call.dict = t_rules->attr.dict_def;
 	node->flags = func->flags;
+	node->flags.impure_func = !func->flags.pure;
 
 	xlat_func_append_arg(node, lhs, logical_ops[op] && cond);
 	xlat_func_append_arg(node, rhs, logical_ops[op] && cond);
diff --git a/src/lib/unlang/xlat_func.c b/src/lib/unlang/xlat_func.c
index 995ad57848..4ce620fd72 100644
--- a/src/lib/unlang/xlat_func.c
+++ b/src/lib/unlang/xlat_func.c
@@ -403,6 +403,7 @@ void xlat_func_flags_set(xlat_t *x, xlat_func_flags_t flags)
 {
 	x->flags.pure = flags & XLAT_FUNC_FLAG_PURE;
 	x->internal = flags & XLAT_FUNC_FLAG_INTERNAL;
+	x->flags.impure_func = !x->flags.pure;
 }
 
 /** Set a print routine for an xlat function.
diff --git a/src/lib/unlang/xlat_priv.h b/src/lib/unlang/xlat_priv.h
index 806163ed2b..08132bb641 100644
--- a/src/lib/unlang/xlat_priv.h
+++ b/src/lib/unlang/xlat_priv.h
@@ -230,6 +230,7 @@ static inline CC_HINT(nonnull) void xlat_flags_merge(xlat_flags_t *parent, xlat_
 	parent->pure &= child->pure; /* purity can only be removed, never added */
 	parent->can_purify |= child->can_purify;
 	parent->constant &= child->constant;
+	parent->impure_func |= child->impure_func;
 }
 
 static inline CC_HINT(nonnull) int xlat_exp_insert_tail(xlat_exp_head_t *head, xlat_exp_t *node)
diff --git a/src/lib/unlang/xlat_redundant.c b/src/lib/unlang/xlat_redundant.c
index 1393c0fe21..54326a31bb 100644
--- a/src/lib/unlang/xlat_redundant.c
+++ b/src/lib/unlang/xlat_redundant.c
@@ -215,6 +215,7 @@ static xlat_exp_t *xlat_exp_func_alloc(TALLOC_CTX *ctx, xlat_t const *func, xlat
 		return NULL;
 	}
 	node->flags = func->flags;
+	node->flags.impure_func = !func->flags.pure;
 	xlat_flags_merge(&node->flags, &args->flags);
 
 	/*
diff --git a/src/lib/unlang/xlat_tokenize.c b/src/lib/unlang/xlat_tokenize.c
index 0013583dfc..fb658ea5b4 100644
--- a/src/lib/unlang/xlat_tokenize.c
+++ b/src/lib/unlang/xlat_tokenize.c
@@ -378,6 +378,7 @@ static int xlat_tokenize_function_args(xlat_exp_head_t *head, fr_sbuff_t *in, tm
 		node->call.func = func;
 		if (t_rules) node->call.dict = t_rules->attr.dict_def;
 		node->flags = func->flags;
+		node->flags.impure_func = !func->flags.pure;
 		node->call.input_type = func->input_type;
 	}
 
@@ -1688,6 +1689,7 @@ 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) | node->call.args->flags.can_purify;
+			node->flags.impure_func = !node->call.func->flags.pure;
 			break;
 
 		/*
@@ -1851,3 +1853,8 @@ done:
 
 	return 0;
 }
+
+bool xlat_impure_func(xlat_exp_head_t const *head)
+{
+	return head->flags.impure_func;
+}