Add menuconfig example/proof of concept

Still needs documentation and some cleanup.

Interface deliberately kept super simple/clunky to focus on the
concepts. Not something you'd actually want to use.

Sample session:

  $ python Kconfiglib/examples/menuconfig.py Kconfiglib/examples/Kmenuconfig

  ======== Example Kconfig configuration ========

  [*] Enable loadable module support (MODULES)
      Bool and tristate symbols
          [*] Bool symbol (BOOL)
                  [ ] Dependent bool symbol (BOOL_DEP)
                  < > Dependent tristate symbol (TRI_DEP)
                  [ ] First prompt (TWO_MENU_NODES)
          < > Tristate symbol (TRI)
          [ ] Second prompt (TWO_MENU_NODES)
              *** These are selected by TRI_DEP ***
          < > Tristate selected by TRI_DEP (SELECTED_BY_TRI_DEP)
          < > Tristate implied by TRI_DEP (IMPLIED_BY_TRI_DEP)
      String, int, and hex symbols
          (foo) String symbol (STRING)
          (747) Int symbol (INT)
          (0xABC) Hex symbol (HEX)
      Various choices
          -*- Bool choice (BOOL_CHOICE)
                  --> Bool choice sym 1 (BOOL_CHOICE_SYM_1)
                      Bool choice sym 2 (BOOL_CHOICE_SYM_2)
          {M} Tristate choice (TRI_CHOICE)
                  < > Tristate choice sym 1 (TRI_CHOICE_SYM_1)
                  < > Tristate choice sym 2 (TRI_CHOICE_SYM_2)
          [ ] Optional bool choice (OPT_BOOL_CHOICE)

  Enter a symbol/choice name, "load_config", or "write_config" (or press CTRL+D to exit): BOOL
  Value for BOOL (available: n, y): n

  ======== Example Kconfig configuration ========

  [*] Enable loadable module support (MODULES)
      Bool and tristate symbols
          [ ] Bool symbol (BOOL)
          < > Tristate symbol (TRI)
          [ ] Second prompt (TWO_MENU_NODES)
              *** These are selected by TRI_DEP ***
          < > Tristate selected by TRI_DEP (SELECTED_BY_TRI_DEP)
          < > Tristate implied by TRI_DEP (IMPLIED_BY_TRI_DEP)
      String, int, and hex symbols
          (foo) String symbol (STRING)
          (747) Int symbol (INT)
          (0xABC) Hex symbol (HEX)
      Various choices
          -*- Bool choice (BOOL_CHOICE)
                  --> Bool choice sym 1 (BOOL_CHOICE_SYM_1)
                      Bool choice sym 2 (BOOL_CHOICE_SYM_2)
          {M} Tristate choice (TRI_CHOICE)
                  < > Tristate choice sym 1 (TRI_CHOICE_SYM_1)
                  < > Tristate choice sym 2 (TRI_CHOICE_SYM_2)
          [ ] Optional bool choice (OPT_BOOL_CHOICE)

  Enter a symbol/choice name, "load_config", or "write_config" (or press CTRL+D to exit): MODULES
  Value for MODULES (available: n, y): n

  ======== Example Kconfig configuration ========

  [ ] Enable loadable module support (MODULES)
      Bool and tristate symbols
          [ ] Bool symbol (BOOL)
          [ ] Tristate symbol (TRI)
          [ ] Second prompt (TWO_MENU_NODES)
              *** These are selected by TRI_DEP ***
          [ ] Tristate selected by TRI_DEP (SELECTED_BY_TRI_DEP)
          [ ] Tristate implied by TRI_DEP (IMPLIED_BY_TRI_DEP)
      String, int, and hex symbols
          (foo) String symbol (STRING)
          (747) Int symbol (INT)
          (0xABC) Hex symbol (HEX)
      Various choices
          -*- Bool choice (BOOL_CHOICE)
                  --> Bool choice sym 1 (BOOL_CHOICE_SYM_1)
                      Bool choice sym 2 (BOOL_CHOICE_SYM_2)
          -*- Tristate choice (TRI_CHOICE)
                  --> Tristate choice sym 1 (TRI_CHOICE_SYM_1)
                      Tristate choice sym 2 (TRI_CHOICE_SYM_2)
          [ ] Optional bool choice (OPT_BOOL_CHOICE)

  Enter a symbol/choice name, "load_config", or "write_config" (or press CTRL+D to exit): ^D

Unsetting modules demonstrates one reason why it makes sense to have
.type be magic and change from TRISTATE to BOOL without modules
(<> = tristate, [] = bool). The C implementation uses the same trick.
(The original type is still available in .orig_type though.)

Piggyback printing of tristates as n, m, y in the warning for invalid
values in set_value().

1 files changed, 7 insertions, 5 deletions

diff --git a/kconfiglib.py b/kconfiglib.py
index d8f070b..f4672b7 100644
--- a/kconfiglib.py
+++ b/kconfiglib.py
@@ -906,7 +906,7 @@ class Kconfig(object):
                     e = e2
 
             raise IOError(
-                'Could not open "{}" ({}: {}). Perhaps the $srctree '
+                "Could not open '{}' ({}: {}). Perhaps the $srctree "
                 "environment variable (which was {}) is set incorrectly. Note "
                 "that the current value of $srctree is saved when the Kconfig "
                 "instance is created (for consistency and to cleanly "
@@ -2539,11 +2539,13 @@ class Symbol(object):
                                             and _is_base_n(value, 16)
                                             and int(value, 16) >= 0)):
 
-            warning = "the value '{}' is invalid for {}, which has type {}" \
-                      .format(value, self.name, TYPE_TO_STR[self.orig_type])
+            # Display tristate values as n, m, y in the warning
+            warning = "the value {} is invalid for {}, which has type {}" \
+                      .format(TRI_TO_STR[value] if value in (0, 1, 2) else
+                                 "'{}'".format(value),
+                              self.name, TYPE_TO_STR[self.orig_type])
 
-            if self.orig_type in (BOOL, TRISTATE) and \
-               value in ("n", "m", "y"):
+            if self.orig_type in (BOOL, TRISTATE) and value in ("n", "m", "y"):
                 warning += ' (pass 0, 1, 2 for n, m, y, respectively)'
 
             self.kconfig._warn(warning)