CMake: confgen.py can't handle hex ranges when generating JSON metadata (IDFGH-1273)

[devanlai]

Environment

• Development Kit: ESP32-DevKitC
• Kit version: v4
• Module or chip used: ESP32-WROOM-32D
• IDF version: v4.0-dev-667-gda13efc17
• Build System: CMake
• Compiler version: crosstool-NG crosstool-ng-1.22.0-80-g6c4433a5 5.2.0
• Operating System: Windows
• Power Supply: USB

Problem Description

When using the CMake build system and a KConfig file with a symbol of type hex and the range of valid values is defined using hex literals, idf.py menuconfig fails due to confgen.py throwing an exception when it tries to convert the hex literals to integers to output the JSON "range" field.

I believe that this could be fixed by tweaking the code that outputs the JSON range field to use int(min_range.str_value, 0) instead of int(min_range.str_value) so that it will accept any well-formed numeric literal that Python accepts.

Steps to repropduce

1. Create a project with a Kconfig file and add a hex symbol with a range defined using hex literals (see below)
2. Run idf.py menuconfig.

Code to reproduce this issue

Sample Kconfig.projbuild to reproduce the issue:

menu "Test hex"
    config TEST_HEX_RANGE
    hex "A hex value"
    range 0x44 0x45
    default 0x44
endmenu

Debug Logs

confgen.py traceback:

Traceback (most recent call last):
  File "C:/Users/devanl/esp/esp-idf/tools/kconfig_new/confgen.py", line 544, in <module>
    main()
  File "C:/Users/devanl/esp/esp-idf/tools/kconfig_new/confgen.py", line 255, in main
    output_function(deprecated_options, config, temp_file)
  File "C:/Users/devanl/esp/esp-idf/tools/kconfig_new/confgen.py", line 501, in write_json_menus
    config.walk_menu(write_node)
  File "C:\Users\devanl\esp\esp-idf\tools\kconfig_new\kconfiglib.py", line 971, in walk_menu
    callback(node)
  File "C:/Users/devanl/esp/esp-idf/tools/kconfig_new/confgen.py", line 469, in write_node
    greatest_range = [int(min_range.str_value), int(max_range.str_value)]
ValueError: invalid literal for int() with base 10: '0x44'

[Alvin1Zhang]

@devanlai Thanks for reporting the issue. We will look into it.

[ulfalizer]

Might want to take the symbol type into account. Something like this will work:

for min_range, max_range, cond_expr in sym.ranges:
    if kconfiglib.expr_value(cond_expr):
        base = 16 if sym.type == kconfiglib.HEX else 10
        greatest_range = [int(min_range.str_value, base),
                          int(max_range.str_value, base)]
        break

hex values are not required to have a 0x prefix. This is some silly compatibility with the C tools.

Related note from the str_value docstring:

Gotcha: For int/hex symbols, the exact format of the value must often be
preserved (e.g., when writing a .config file), hence why you can't get it
directly as an int. Do int(int_sym.str_value) or
int(hex_sym.str_value, 16) to get the integer value.

[dobairoland]

Thank you @devanlai for letting us know about this problem and thank you @ulfalizer for the suggestion. The fix will be added soon.

[ulfalizer]

You guys should update Kconfiglib someday by the way. Tons of improvements and optimizations, and probably no API changes that'd affect you (there's a list in the README).

Would help avoid user issues like this one too.

Sorry for nagging.~