Warn if user (.config) value is outside of 'range'

Example warning:

  warning: user value 0x100 on the hex symbol HEX (defined at Kconfig:18) ignored due to being outside the active range ([0x13, 0x73]) -- falling back on defaults

This is a Kconfiglib-exclusive warning. It might be tricky to implement
in the C tools, due to weird two-phase handling of int/hex symbols.

There is unfortunately no easy way to map the warning back to a .config
line, as the active 'range' can't be known in general until the entire
configuration has been read (consider 'range 0 10 if FOO' for example).
Instead, the warning is generated when the symbol value is calculated.

2 files changed, 26 insertions, 8 deletions

diff --git a/kconfiglib.py b/kconfiglib.py
index e9d9303..e002cc0 100644
--- a/kconfiglib.py
+++ b/kconfiglib.py
@@ -2806,16 +2806,29 @@ class Symbol(object):
             else:
                 has_active_range = False
 
-            if vis and self.user_value is not None and \
-               (not has_active_range or
-                low <= int(self.user_value, base) <= high):
+            # Defaults are used if the symbol is invisible, lacks a user value,
+            # or has an out-of-range user value.
+            use_defaults = True
 
-                # If the user value is well-formed and satisfies range
-                # contraints, it is stored in exactly the same form as
-                # specified in the assignment (with or without "0x", etc.)
-                val = self.user_value
+            if vis and self.user_value is not None:
+                user_val = int(self.user_value, base)
+                if has_active_range and not low <= user_val <= high:
+                    num2str = str if base == 10 else hex
+                    self.kconfig._warn(
+                        "user value {} on the {} symbol {} ignored due to "
+                        "being outside the active range ([{}, {}]) -- falling "
+                        "back on defaults"
+                        .format(num2str(user_val), TYPE_TO_STR[self.orig_type],
+                                _name_and_loc_str(self),
+                                num2str(low), num2str(high)))
+                else:
+                    # If the user value is well-formed and satisfies range
+                    # contraints, it is stored in exactly the same form as
+                    # specified in the assignment (with or without "0x", etc.)
+                    val = self.user_value
+                    use_defaults = False
 
-            else:
+            if use_defaults:
                 # No user value or invalid user value. Look at defaults.
 
                 for val_expr, cond in self.defaults:
diff --git a/testsuite.py b/testsuite.py
index c66f42c..110e6ec 100644
--- a/testsuite.py
+++ b/testsuite.py
@@ -1131,6 +1131,9 @@ g
 
     # User values and dependent ranges
 
+    # Avoid warnings for assigning values outside the active range
+    c.disable_warnings()
+
     def verify_range(sym_name, low, high, default):
         """
         Tests that the values in the range 'low'-'high' can be assigned, and
@@ -1200,6 +1203,8 @@ g
     verify_value("INACTIVE_RANGE", "2")
     verify_value("ACTIVE_RANGE", "1")
 
+    c.enable_warnings()
+
 
     print("Testing defconfig_filename")