esp-idf/Kconfig.compiler

menu "Compiler options"

choice OPTIMIZATION_COMPILER
    prompt "Optimization Level"
    default OPTIMIZATION_LEVEL_DEBUG
    help
        This option sets compiler optimization level (gcc -O argument).

        - for "Release" setting, -Os flag is added to CFLAGS.
        - for "Debug" setting, -Og flag is added to CFLAGS.

        "Release" with -Os produces smaller & faster compiled code but it
        may be harder to correlated code addresses to source files when debugging.

        To add custom optimization settings, set CFLAGS and/or CPPFLAGS
        in project makefile, before including $(IDF_PATH)/make/project.mk. Note that
        custom optimization levels may be unsupported.

config OPTIMIZATION_LEVEL_DEBUG
    bool "Debug (-Og)"
config OPTIMIZATION_LEVEL_RELEASE
    bool "Release (-Os)"
endchoice

choice OPTIMIZATION_ASSERTION_LEVEL
    prompt "Assertion level"
    default OPTIMIZATION_ASSERTIONS_ENABLED
    help
        Assertions can be:

        - Enabled. Failure will print verbose assertion details. This is the default.

        - Set to "silent" to save code size (failed assertions will abort() but user
          needs to use the aborting address to find the line number with the failed assertion.)

        - Disabled entirely (not recommended for most configurations.) -DNDEBUG is added
          to CPPFLAGS in this case.

config OPTIMIZATION_ASSERTIONS_ENABLED
    prompt "Enabled"
    bool
    help
        Enable assertions. Assertion content and line number will be printed on failure.

config OPTIMIZATION_ASSERTIONS_SILENT
    prompt "Silent (saves code size)"
    bool
    help
        Enable silent assertions. Failed assertions will abort(), user needs to
        use the aborting address to find the line number with the failed assertion.

config OPTIMIZATION_ASSERTIONS_DISABLED
    prompt "Disabled (sets -DNDEBUG)"
    bool
    help
        If assertions are disabled, -DNDEBUG is added to CPPFLAGS.

endchoice # assertions

menuconfig CXX_EXCEPTIONS
   bool "Enable C++ exceptions"
   default n
   help
       Enabling this option compiles all IDF C++ files with exception support enabled.

       Disabling this option disables C++ exception support in all compiled files, and any libstdc++ code which throws
       an exception will abort instead.

       Enabling this option currently adds an additional ~500 bytes of heap overhead
       when an exception is thrown in user code for the first time.

config CXX_EXCEPTIONS_EMG_POOL_SIZE
    int "Emergency Pool Size"
    default 0
    depends on CXX_EXCEPTIONS
    help
       Size (in bytes) of the emergency memory pool for C++ exceptions. This pool will be used to allocate
       memory for thrown exceptions when there is not enough memory on the heap.

choice STACK_CHECK_MODE
    prompt "Stack smashing protection mode"
    default STACK_CHECK_NONE
    help
        Stack smashing protection mode. Emit extra code to check for buffer overflows, such as stack
        smashing attacks. This is done by adding a guard variable to functions with vulnerable objects.
        The guards are initialized when a function is entered and then checked when the function exits.
        If a guard check fails, program is halted. Protection has the following modes:

        - In NORMAL mode (GCC flag: -fstack-protector) only functions that call alloca,
          and functions with buffers larger than 8 bytes are protected.
        
        - STRONG mode (GCC flag: -fstack-protector-strong) is like NORMAL, but includes
          additional functions to be protected -- those that have local array definitions,
          or have references to local frame addresses.
        
        - In OVERALL mode (GCC flag: -fstack-protector-all) all functions are protected.

        Modes have the following impact on code performance and coverage:

        - performance: NORMAL > STRONG > OVERALL
        
        - coverage: NORMAL < STRONG < OVERALL


config STACK_CHECK_NONE
    bool "None"
config STACK_CHECK_NORM
    bool "Normal"
config STACK_CHECK_STRONG
    bool "Strong"
config STACK_CHECK_ALL
    bool "Overall"
endchoice

config STACK_CHECK
    bool
    default !STACK_CHECK_NONE
    help
        Stack smashing protection.

config WARN_WRITE_STRINGS
    bool "Enable -Wwrite-strings warning flag"
    default "n"
    help
        Adds -Wwrite-strings flag for the C/C++ compilers.

        For C, this gives string constants the type ``const char[]`` so that
        copying the address of one into a non-const ``char *`` pointer
        produces a warning. This warning helps to find at compile time code
        that tries to write into a string constant.

        For C++, this warns about the deprecated conversion from string
        literals to ``char *``.

endmenu # Compiler Options