kconfig: remove tristate choice support

I previously submitted a fix for a bug in the choice feature [1], where
I mentioned, "Another (much cleaner) approach would be to remove the
tristate choice support entirely".

There are more issues in the tristate choice feature. For example, you
can observe a couple of bugs in the following test code.

[Test Code]

    config MODULES
            def_bool y
            modules

    choice
            prompt "tristate choice"
            default A

    config A
            tristate "A"

    config B
            tristate "B"

    endchoice

Bug 1: the 'default' property is not correctly processed

'make alldefconfig' produces:

    CONFIG_MODULES=y
    # CONFIG_A is not set
    # CONFIG_B is not set

However, the correct output should be:

    CONFIG_MODULES=y
    CONFIG_A=y
    # CONFIG_B is not set

The unit test file, scripts/kconfig/tests/choice/alldef_expected_config,
is wrong as well.

Bug 2: choice members never get 'y' with randconfig

For the test code above, the following combinations are possible:

               A    B
        (1)    y    n
        (2)    n    y
        (3)    m    m
        (4)    m    n
        (5)    n    m
        (6)    n    n

'make randconfig' never produces (1) or (2).

These bugs are fixable, but a more critical problem is the lack of a
sensible syntax to specify the default for the tristate choice.
The default for the choice must be one of the choice members, which
cannot specify any of the patterns (3) through (6) above.

In addition, I have never seen it being used in a useful way.

The following commits removed unnecessary use of tristate choices:

 - df8df5e4bc37 ("usb: get rid of 'choice' for legacy gadget drivers")
 - bfb57ef0544a ("rapidio: remove choice for enumeration")

This commit removes the tristate choice support entirely, which allows
me to delete a lot of code, making further refactoring easier.

Note:
This includes the revert of commit fa64e5f6a35e ("kconfig/symbol.c:
handle choice_values that depend on 'm' symbols"). It was suspicious
because it did not address the root cause but introduced inconsistency
in visibility between choice members and other symbols.

[1]: https://lore.kernel.org/linux-kbuild/20240427104231.2728905-1-masahiroy@kernel.org/T/#m0a1bb6992581462ceca861b409bb33cb8fd7dbae

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

9 files changed, 0 insertions, 53 deletions

diff --git a/scripts/kconfig/tests/choice/Kconfig b/scripts/kconfig/tests/choice/Kconfig
index 8cdda40868a1..cd252579a623 100644
--- a/scripts/kconfig/tests/choice/Kconfig
+++ b/scripts/kconfig/tests/choice/Kconfig
@@ -1,10 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
-config MODULES
-	bool "Enable loadable module support"
-	modules
-	default y
-
 choice
 	prompt "boolean choice"
 	default BOOL_CHOICE1
@@ -16,15 +11,3 @@ config BOOL_CHOICE1
 	bool "choice 1"
 
 endchoice
-
-choice
-	prompt "tristate choice"
-	default TRI_CHOICE1
-
-config TRI_CHOICE0
-	tristate "choice 0"
-
-config TRI_CHOICE1
-	tristate "choice 1"
-
-endchoice
diff --git a/scripts/kconfig/tests/choice/__init__.py b/scripts/kconfig/tests/choice/__init__.py
index 05e162220085..0fc7bf9b5c78 100644
--- a/scripts/kconfig/tests/choice/__init__.py
+++ b/scripts/kconfig/tests/choice/__init__.py
@@ -1,11 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 """
 Basic choice tests.
-
-The handling of 'choice' is a bit complicated part in Kconfig.
-
-The behavior of 'y' choice is intuitive.  If choice values are tristate,
-the choice can be 'm' where each value can be enabled independently.
 """
 
 
@@ -14,11 +9,6 @@ def test_oldask0(conf):
     assert conf.stdout_contains('oldask0_expected_stdout')
 
 
-def test_oldask1(conf):
-    assert conf.oldaskconfig('oldask1_config') == 0
-    assert conf.stdout_contains('oldask1_expected_stdout')
-
-
 def test_allyes(conf):
     assert conf.allyesconfig() == 0
     assert conf.config_contains('allyes_expected_config')
diff --git a/scripts/kconfig/tests/choice/alldef_expected_config b/scripts/kconfig/tests/choice/alldef_expected_config
index 7a754bf4be94..b359a2e6493e 100644
--- a/scripts/kconfig/tests/choice/alldef_expected_config
+++ b/scripts/kconfig/tests/choice/alldef_expected_config
@@ -1,5 +1,2 @@
-CONFIG_MODULES=y
 # CONFIG_BOOL_CHOICE0 is not set
 CONFIG_BOOL_CHOICE1=y
-# CONFIG_TRI_CHOICE0 is not set
-# CONFIG_TRI_CHOICE1 is not set
diff --git a/scripts/kconfig/tests/choice/allmod_expected_config b/scripts/kconfig/tests/choice/allmod_expected_config
index d1f51651740c..b359a2e6493e 100644
--- a/scripts/kconfig/tests/choice/allmod_expected_config
+++ b/scripts/kconfig/tests/choice/allmod_expected_config
@@ -1,5 +1,2 @@
-CONFIG_MODULES=y
 # CONFIG_BOOL_CHOICE0 is not set
 CONFIG_BOOL_CHOICE1=y
-CONFIG_TRI_CHOICE0=m
-CONFIG_TRI_CHOICE1=m
diff --git a/scripts/kconfig/tests/choice/allno_expected_config b/scripts/kconfig/tests/choice/allno_expected_config
index b88ee7a43136..b359a2e6493e 100644
--- a/scripts/kconfig/tests/choice/allno_expected_config
+++ b/scripts/kconfig/tests/choice/allno_expected_config
@@ -1,5 +1,2 @@
-# CONFIG_MODULES is not set
 # CONFIG_BOOL_CHOICE0 is not set
 CONFIG_BOOL_CHOICE1=y
-# CONFIG_TRI_CHOICE0 is not set
-CONFIG_TRI_CHOICE1=y
diff --git a/scripts/kconfig/tests/choice/allyes_expected_config b/scripts/kconfig/tests/choice/allyes_expected_config
index 8a76c1816893..b359a2e6493e 100644
--- a/scripts/kconfig/tests/choice/allyes_expected_config
+++ b/scripts/kconfig/tests/choice/allyes_expected_config
@@ -1,5 +1,2 @@
-CONFIG_MODULES=y
 # CONFIG_BOOL_CHOICE0 is not set
 CONFIG_BOOL_CHOICE1=y
-# CONFIG_TRI_CHOICE0 is not set
-CONFIG_TRI_CHOICE1=y
diff --git a/scripts/kconfig/tests/choice/oldask0_expected_stdout b/scripts/kconfig/tests/choice/oldask0_expected_stdout
index d2257db46423..80ec34c61ebc 100644
--- a/scripts/kconfig/tests/choice/oldask0_expected_stdout
+++ b/scripts/kconfig/tests/choice/oldask0_expected_stdout
@@ -1,8 +1,4 @@
-Enable loadable module support (MODULES) [Y/n/?] (NEW) 
 boolean choice
   1. choice 0 (BOOL_CHOICE0) (NEW)
 > 2. choice 1 (BOOL_CHOICE1) (NEW)
 choice[1-2?]: 
-tristate choice [M/y/?] (NEW) 
-  choice 0 (TRI_CHOICE0) [N/m/?] (NEW) 
-  choice 1 (TRI_CHOICE1) [N/m/?] (NEW) 
diff --git a/scripts/kconfig/tests/choice/oldask1_config b/scripts/kconfig/tests/choice/oldask1_config
deleted file mode 100644
index 0f417856c81c..000000000000
--- a/scripts/kconfig/tests/choice/oldask1_config
+++ /dev/null
@@ -1 +0,0 @@
-# CONFIG_MODULES is not set
diff --git a/scripts/kconfig/tests/choice/oldask1_expected_stdout b/scripts/kconfig/tests/choice/oldask1_expected_stdout
deleted file mode 100644
index ffa20ad7f38e..000000000000
--- a/scripts/kconfig/tests/choice/oldask1_expected_stdout
+++ /dev/null
@@ -1,9 +0,0 @@
-Enable loadable module support (MODULES) [N/y/?] 
-boolean choice
-  1. choice 0 (BOOL_CHOICE0) (NEW)
-> 2. choice 1 (BOOL_CHOICE1) (NEW)
-choice[1-2?]: 
-tristate choice
-  1. choice 0 (TRI_CHOICE0) (NEW)
-> 2. choice 1 (TRI_CHOICE1) (NEW)
-choice[1-2?]: