kconfig: clean-up reverse dependency help implementation

This commit splits out the special E_OR handling ('-' instead of '||')
into a dedicated helper expr_print_revdev().

Restore the original expr_print() prior to commit 1ccb2714
("kconfig: make "Selected by:" and "Implied by:" readable").

This makes sense because:

  - We need to chop those expressions only when printing the reverse
    dependency, and only when E_OR is encountered

  - Otherwise, it should be printed as before, so fall back to
    expr_print()

This also improves the behavior; for a single line, it was previously
displayed in the same line as "Selected by", like this:

  Selected by: A [=n] && B [=n]

This will be displayed in a new line, consistently:

  Selected by:
  - A [=n] && B [=n]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>

scripts/kconfig/expr.c

@@ -1179,7 +1179,9 @@ struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2)
 	return expr_get_leftmost_symbol(ret);
 }
 
-static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken, bool revdep)
+void expr_print(struct expr *e,
+		void (*fn)(void *, struct symbol *, const char *),
+		void *data, int prevtoken)
 {
 	if (!e) {
 		fn(data, NULL, "y");
@@ -1234,14 +1236,9 @@ static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, con
 		fn(data, e->right.sym, e->right.sym->name);
 		break;
 	case E_OR:
-		if (revdep && e->left.expr->type != E_OR)
-			fn(data, NULL, "\n  - ");
-		__expr_print(e->left.expr, fn, data, E_OR, revdep);
-		if (revdep)
-			fn(data, NULL, "\n  - ");
-		else
+		expr_print(e->left.expr, fn, data, E_OR);
 		fn(data, NULL, " || ");
-		__expr_print(e->right.expr, fn, data, E_OR, revdep);
+		expr_print(e->right.expr, fn, data, E_OR);
 		break;
 	case E_AND:
 		expr_print(e->left.expr, fn, data, E_AND);
@@ -1274,11 +1271,6 @@ static void __expr_print(struct expr *e, void (*fn)(void *, struct symbol *, con
 		fn(data, NULL, ")");
 }
 
-void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken)
-{
-	__expr_print(e, fn, data, prevtoken, false);
-}
-
 static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
 {
 	xfwrite(str, strlen(str), 1, data);
@@ -1329,7 +1321,21 @@ void expr_gstr_print(struct expr *e, struct gstr *gs)
  * line with a minus. This makes expressions much easier to read.
  * Suitable for reverse dependency expressions.
  */
+static void expr_print_revdep(struct expr *e,
+			      void (*fn)(void *, struct symbol *, const char *),
+			      void *data)
+{
+	if (e->type == E_OR) {
+		expr_print_revdep(e->left.expr, fn, data);
+		expr_print_revdep(e->right.expr, fn, data);
+	} else {
+		fn(data, NULL, "  - ");
+		expr_print(e, fn, data, E_NONE);
+		fn(data, NULL, "\n");
+	}
+}
+
 void expr_gstr_print_revdep(struct expr *e, struct gstr *gs)
 {
-	__expr_print(e, expr_print_gstr_helper, gs, E_NONE, true);
+	expr_print_revdep(e, expr_print_gstr_helper, gs);
 }

scripts/kconfig/menu.c

@@ -829,15 +829,15 @@ static void get_symbol_str(struct gstr *r, struct symbol *sym,
 	get_symbol_props_str(r, sym, P_SELECT, _("  Selects: "));
 	if (sym->rev_dep.expr) {
 		str_append(r, _("  Selected by: "));
-		expr_gstr_print_revdep(sym->rev_dep.expr, r);
 		str_append(r, "\n");
+		expr_gstr_print_revdep(sym->rev_dep.expr, r);
 	}
 
 	get_symbol_props_str(r, sym, P_IMPLY, _("  Implies: "));
 	if (sym->implied.expr) {
 		str_append(r, _("  Implied by: "));
-		expr_gstr_print_revdep(sym->implied.expr, r);
 		str_append(r, "\n");
+		expr_gstr_print_revdep(sym->implied.expr, r);
 	}
 
 	str_append(r, "\n\n");