From 0a9dc19c4c35fb6e6528da575547b2025c43c78f Mon Sep 17 00:00:00 2001
From: Arnaud Lacombe <lacombar@gmail.com>
Date: Sun, 26 Sep 2010 16:24:08 -0400
Subject: [PATCH] --- yaml --- r: 227665 b: refs/heads/master c:
 1137c56b7420c801147e0863845c03b07554721a h: refs/heads/master i:   227663:
 9d8d8bdda5ed3d0892ac5c463949108ae85af7a1 v: v3

---
 [refs]                         |  2 +-
 trunk/scripts/kconfig/expr.c   | 42 ++++++++++++++++++++++++++++++++++
 trunk/scripts/kconfig/symbol.c |  6 ++++-
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index e64b9f12b873..bf818c132638 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ab60bd0b92ec57c98df08616b7d0664be5551eae
+refs/heads/master: 1137c56b7420c801147e0863845c03b07554721a
diff --git a/trunk/scripts/kconfig/expr.c b/trunk/scripts/kconfig/expr.c
index 330e7c0048a8..65531a7f28a8 100644
--- a/trunk/scripts/kconfig/expr.c
+++ b/trunk/scripts/kconfig/expr.c
@@ -1013,6 +1013,48 @@ int expr_compare_type(enum expr_type t1, enum expr_type t2)
 #endif
 }
 
+static inline struct expr *
+expr_get_leftmost_symbol(const struct expr *e)
+{
+
+	if (e == NULL)
+		return NULL;
+
+	while (e->type != E_SYMBOL)
+		e = e->left.expr;
+
+	return expr_copy(e);
+}
+
+/*
+ * Given expression `e1' and `e2', returns the leaf of the longest
+ * sub-expression of `e1' not containing 'e2.
+ */
+struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2)
+{
+	struct expr *ret;
+
+	switch (e1->type) {
+	case E_OR:
+		return expr_alloc_and(
+		    expr_simplify_unmet_dep(e1->left.expr, e2),
+		    expr_simplify_unmet_dep(e1->right.expr, e2));
+	case E_AND: {
+		struct expr *e;
+		e = expr_alloc_and(expr_copy(e1), expr_copy(e2));
+		e = expr_eliminate_dups(e);
+		ret = (!expr_eq(e, e1)) ? e1 : NULL;
+		expr_free(e);
+		break;
+		}
+	default:
+		ret = e1;
+		break;
+	}
+
+	return expr_get_leftmost_symbol(ret);
+}
+
 void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken)
 {
 	if (!e) {
diff --git a/trunk/scripts/kconfig/symbol.c b/trunk/scripts/kconfig/symbol.c
index 60830ce4a0a9..fa52e6f44ac4 100644
--- a/trunk/scripts/kconfig/symbol.c
+++ b/trunk/scripts/kconfig/symbol.c
@@ -351,12 +351,16 @@ void sym_calc_value(struct symbol *sym)
 			}
 		calc_newval:
 			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
+				struct expr *e;
+				e = expr_simplify_unmet_dep(sym->rev_dep.expr,
+				    sym->dir_dep.expr);
 				fprintf(stderr, "warning: (");
-				expr_fprint(sym->rev_dep.expr, stderr);
+				expr_fprint(e, stderr);
 				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
 					sym->name);
 				expr_fprint(sym->dir_dep.expr, stderr);
 				fprintf(stderr, ")\n");
+				expr_free(e);
 			}
 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 		}