kconfig: tests: add a test for randconfig with dependent choices

Since commit 3b9a19e08960 ("kconfig: loop as long as we changed some
symbols in randconfig"), conf_set_all_new_symbols() is repeated until
there is no more choice left to be shuffled. The motivation was to
shuffle a choice nested in another choice.

Although commit 09d5873e4d1f ("kconfig: allow only 'config', 'comment',
and 'if' inside 'choice'") disallowed the nested choice structure,
we must still keep 3b9a19e08960 because there are still cases where
conf_set_all_new_symbols() must iterate.

scripts/kconfig/tests/choice_randomize/Kconfig is the test case.
The second choice depends on 'B', which is the member of the first
choice.

With 3b9a19e08960 reverted, we would never get the pattern specified by
scripts/kconfig/tests/choice_randomize/expected_config2.

A real example can be found in lib/Kconfig.debug. Without 3b9a19e08960,
the randconfig would not shuffle the "Compressed Debug information"
choice, which depends on DEBUG_INFO, which is derived from another
choice "Debug information".

My goal is to refactor Kconfig so that randconfig will work more
simply, without using the loop.

For now, let's add a test case to ensure all dependent choices are
shuffled, as it is a somewhat tricky case for the current Kconfig.

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

5 files changed, 78 insertions, 0 deletions

diff --git a/scripts/kconfig/tests/choice_randomize/Kconfig b/scripts/kconfig/tests/choice_randomize/Kconfig
new file mode 100644
index 00000000000000..93a1699ce3cb79
--- /dev/null
+++ b/scripts/kconfig/tests/choice_randomize/Kconfig
@@ -0,0 +1,22 @@
+choice
+	prompt "choose A or B"
+
+config A
+	bool "A"
+
+config B
+	bool "B"
+
+endchoice
+
+choice
+	prompt "choose X or Y"
+	depends on B
+
+config X
+	bool "X"
+
+config Y
+	bool "Y"
+
+endchoice
diff --git a/scripts/kconfig/tests/choice_randomize/__init__.py b/scripts/kconfig/tests/choice_randomize/__init__.py
new file mode 100644
index 00000000000000..d380045be79c0b
--- /dev/null
+++ b/scripts/kconfig/tests/choice_randomize/__init__.py
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0-only
+"""
+Randomize all dependent choices
+
+This is a somewhat tricky case for randconfig; the visibility of one choice is
+determined by a member of another choice. Randconfig should be able to generate
+all possible patterns.
+"""
+
+
+def test(conf):
+
+    expected0 = False
+    expected1 = False
+    expected2 = False
+
+    for i in range(100):
+        assert conf.randconfig(seed=i) == 0
+
+        if conf.config_matches('expected_config0'):
+            expected0 = True
+        elif conf.config_matches('expected_config1'):
+            expected1 = True
+        elif conf.config_matches('expected_config2'):
+            expected2 = True
+        else:
+            assert False
+
+        if expected0 and expected1 and expected2:
+            break
+
+    assert expected0
+    assert expected1
+    assert expected2
diff --git a/scripts/kconfig/tests/choice_randomize/expected_config0 b/scripts/kconfig/tests/choice_randomize/expected_config0
new file mode 100644
index 00000000000000..f692273237596a
--- /dev/null
+++ b/scripts/kconfig/tests/choice_randomize/expected_config0
@@ -0,0 +1,6 @@
+#
+# Automatically generated file; DO NOT EDIT.
+# Main menu
+#
+CONFIG_A=y
+# CONFIG_B is not set
diff --git a/scripts/kconfig/tests/choice_randomize/expected_config1 b/scripts/kconfig/tests/choice_randomize/expected_config1
new file mode 100644
index 00000000000000..bf83784c9b2a59
--- /dev/null
+++ b/scripts/kconfig/tests/choice_randomize/expected_config1
@@ -0,0 +1,8 @@
+#
+# Automatically generated file; DO NOT EDIT.
+# Main menu
+#
+# CONFIG_A is not set
+CONFIG_B=y
+CONFIG_X=y
+# CONFIG_Y is not set
diff --git a/scripts/kconfig/tests/choice_randomize/expected_config2 b/scripts/kconfig/tests/choice_randomize/expected_config2
new file mode 100644
index 00000000000000..38f93a8f37bdbc
--- /dev/null
+++ b/scripts/kconfig/tests/choice_randomize/expected_config2
@@ -0,0 +1,8 @@
+#
+# Automatically generated file; DO NOT EDIT.
+# Main menu
+#
+# CONFIG_A is not set
+CONFIG_B=y
+# CONFIG_X is not set
+CONFIG_Y=y