The boolean 'choice' is used to list exclusively selected config
options.

You must not add a dependency between choice members, because such a
dependency would create an invisible entry.

In the following test case, it is impossible to choose 'C'.

[Test Case 1]

  choice
          prompt "Choose one, but how to choose C?"

  config A
          bool "A"

  config B
          bool "B"

  config C
          bool "C"
          depends on A

  endchoice

Hence, Kconfig shows the following error message:

  Kconfig:1:error: recursive dependency detected!
  Kconfig:1:      choice <choice> contains symbol C
  Kconfig:10:     symbol C is part of choice A
  Kconfig:4:      symbol A is part of choice <choice>
  For a resolution refer to Documentation/kbuild/kconfig-language.rst
  subsection "Kconfig recursive dependency limitations"

However, Kconfig does not report anything for the following similar code:

[Test Case 2]

  choice
         prompt "Choose one, but how to choose B?"

  config A
          bool "A"

  config B
          bool "B"
          depends on A

  config C
          bool "C"

  endchoice

This is because menu_finalize() reparents the menu tree when an entry
depends on the preceding one.

With reparenting, the menu tree:

  choice
   |- A
   |- B
   \- C

... will be transformed into the following structure:

  choice
   |- A
   |  \- B
   \- C

Consequently, Kconfig considers only 'A' and 'C' as choice members.
This behavior is awkward. The second test case should be an error too.

This commit stops reparenting inside a choice.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This can be checked on-the-fly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Currently, get_symbol_str() uses a tricky approach to traverse the
associated menus.

With relevant menus now linked to the symbol using a linked list,
use list_for_each_entry() for iterating on the menus.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Currently, there is no direct link from (struct symbol) to (struct menu).

It is still possible to access associated menus through the P_SYMBOL
property, because property::menu is the relevant menu entry, but it
results in complex code, as seen in get_symbol_str().

Use a linked list for simpler traversal of relevant menus.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Do not feed back the choice type to choice values.

Each choice value should explicitly specify 'bool' or 'tristate',
as all the Kconfig files already do. If the type were missing,
"config symbol defined without type" would be shown.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The struct list_head is often embedded in other structures, while other
code is used in C functions.

By separating struct list_head into its own header, other headers are no
longer required to include the entire list.h.

This is similar to the kernel space, where struct list_head is defined
in <linux/types.h> instead of <linux/list.h>.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Currently, file_lookup() returns a pointer to (struct file), but the
callers use only file->name.

Make it return the ->name member directly.

This adjustment encapsulates struct file and file_list as internal
implementation.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

struct file has two link nodes, 'next' and 'parent'.

The former is used to link files in the 'file_list' linked list,
which manages the list of Kconfig files seen so far.

The latter is used to link files in the 'current_file' linked list,
which manages the inclusion ("source") tree.

The latter should be tracked together with the lexer state.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

struct property is linked to struct file for diagnostic purposes.
It is always used to retrieve the file name through prop->file->name.

Associate struct property with the file name directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

struct menu is linked to struct file for diagnostic purposes.
It is always used to retrieve the file name through menu->file->name.

Associate struct menu with the file name directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>