menuconfig: Improve/fix promptless choice handling

The code assumed that all parent (interface) menus always have a prompt,
which is false for items in promptless choices. This lead to a crash
e.g. when viewing the symbol information for a symbol within a
promptless choice.

Promptless choices with children can show up "legitimately" when people
define choices in multiple locations to add symbols, though this is
broken in the C tools.

Use standard_sc_expr_str(node.item) instead of the non-existing prompt
for promptless choices. That way they show up as
<choice (name if any>)>, which is consistent with how they're shown
elsewhere.

This commit also changes how choices names are displayed in
show-name/show-all mode, to the standard_sc_expr_str() format.

1 files changed, 26 insertions, 9 deletions

diff --git a/menuconfig.py b/menuconfig.py
index 14edb83..d5cac8f 100755
--- a/menuconfig.py
+++ b/menuconfig.py
@@ -1190,7 +1190,11 @@ def _draw_main():
 
     menu = _cur_menu
     while menu is not _kconf.top_node:
-        menu_prompts.append(menu.prompt[0])
+        # Promptless choices can be entered in show-all mode. Use
+        # standard_sc_expr_str() for them, so they show up as
+        # <choice (name if any)>.
+        menu_prompts.append(menu.prompt[0] if menu.prompt else
+                            standard_sc_expr_str(menu.item))
         menu = _parent_menu(menu)
     menu_prompts.append("(top menu)")
     menu_prompts.reverse()
@@ -2489,7 +2493,11 @@ def _menu_path_info(node):
 
     node = _parent_menu(node)
     while node is not _kconf.top_node:
-        path = " -> " + node.prompt[0] + path
+        # Promptless choices might appear among the parents. Use
+        # standard_sc_expr_str() for them, so that they show up as
+        # <choice (name if any)>.
+        path = " -> " + (node.prompt[0] if node.prompt else
+                         standard_sc_expr_str(node.item)) + path
         node = _parent_menu(node)
 
     return "(top menu)" + path
@@ -2645,13 +2653,13 @@ def _node_str(node):
     # This approach gives nice alignment for empty string symbols ("()  Foo")
     s = "{:{}}".format(_value_str(node), 3 + indent)
 
-    # 'not node.prompt' can only be True in show-all mode
-    if not node.prompt or \
-       (_show_name and
-        (isinstance(node.item, Symbol) or
-         (isinstance(node.item, Choice) and node.item.name))):
-
-        s += " <{}>".format(node.item.name)
+    if _should_show_name(node):
+        if isinstance(node.item, Symbol):
+            s += " <{}>".format(node.item.name)
+        else:
+            # For choices, use standard_sc_expr_str(). That way they show up as
+            # <choice (name if any)>.
+            s += " " + standard_sc_expr_str(node.item)
 
     if node.prompt:
         s += " "
@@ -2687,6 +2695,15 @@ def _node_str(node):
 
     return s
 
+def _should_show_name(node):
+    # Returns True if 'node' is a symbol or choice whose name should shown (if
+    # any, as names are optional for choices)
+
+    # The 'not node.prompt' case only hits in show-all mode, for promptless
+    # symbols and choices
+    return not node.prompt or \
+           (_show_name and isinstance(node.item, (Symbol, Choice)))
+
 def _value_str(node):
     # Returns the value part ("[*]", "<M>", "(foo)" etc.) of a menu node