[Linux-kernel-mentees] [PATCH] checkpatch: add --fix option to IS_ENABLED_CONFIG check

[Dwaipayan Ray]

> > checkpatch correspondingly has a check for IS_ENABLED() without
> > CONFIG_<FOO>.
> > Add a --fix option to the check to automatically correct the argument.
> >
> > Macros like:
> >  #if IS_ENABLED(THERMAL)
> >
> > is corrected to:
> >  #if IS_ENABLED(CONFIG_THERMAL)
>
> I think adding a --fix option here is not a good option.
>
> Look at the existing uses without CONFIG and tell me
> the majority of them need to have CONFIG added.
>
> $ git grep -P '\bIS_ENABLED\s*\(\s*(?!CONFIG_)'
> arch/arc/include/asm/asserts.h: chk_opt_strict(#opt_name, hw_exists, IS_ENABLED(opt_name));     \
> arch/arc/include/asm/asserts.h: chk_opt_weak(#opt_name, hw_exists, IS_ENABLED(opt_name));       \
> arch/arc/include/asm/setup.h:#define IS_USED_CFG(cfg)   IS_USED_RUN(IS_ENABLED(cfg))
> arch/arm64/include/asm/alternative-macros.h:    __ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg))
> arch/arm64/include/asm/alternative-macros.h:    alternative_insn insn1, insn2, cap, IS_ENABLED(cfg)
> arch/arm64/include/asm/cpufeature.h:    (IS_ENABLED(config) ? FTR_VISIBLE : FTR_HIDDEN)
> arch/x86/mm/numa.c:     if (IS_ENABLED(NODE_NOT_IN_PAGE_FLAGS)) {
> drivers/gpu/drm/exynos/exynos_drm_drv.c:#define DRV_PTR(drv, cond) (IS_ENABLED(cond) ? &drv : NULL)
> drivers/gpu/drm/i915/i915_utils.h: * This is a lookalike for IS_ENABLED() that takes a kconfig value,
> drivers/gpu/drm/i915/i915_utils.h: * Sadly IS_ENABLED() itself does not work with kconfig values.
> drivers/gpu/drm/rockchip/rockchip_drm_drv.c:    if (IS_ENABLED(cond) && \
> drivers/net/wireguard/allowedips.c:             WARN_ON(IS_ENABLED(DEBUG) && *len >= 128);
> drivers/net/wireguard/allowedips.c:             WARN_ON(IS_ENABLED(DEBUG) && len >= 128);                      \
> drivers/net/wireguard/noise.c:  WARN_ON(IS_ENABLED(DEBUG) &&
> drivers/net/wireguard/selftest/allowedips.c:    if (IS_ENABLED(DEBUG_PRINT_TRIE_GRAPHVIZ)) {
> drivers/net/wireguard/selftest/allowedips.c:    if (IS_ENABLED(DEBUG_PRINT_TRIE_GRAPHVIZ)) {
> drivers/net/wireguard/selftest/allowedips.c:    if (IS_ENABLED(DEBUG_RANDOM_TRIE) && success)
> drivers/phy/broadcom/phy-brcm-usb-init.h:       if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(__BIG_ENDIAN))
> drivers/phy/broadcom/phy-brcm-usb-init.h:       if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(__BIG_ENDIAN))
> include/asm-generic/vmlinux.lds.h:#define OF_TABLE(cfg, name)   __OF_TABLE(IS_ENABLED(cfg), name)
> include/crypto/blake2s.h:       WARN_ON(IS_ENABLED(DEBUG) && (!outlen || outlen > BLAKE2S_HASH_SIZE ||
> include/crypto/blake2s.h:       WARN_ON(IS_ENABLED(DEBUG) && ((!in && inlen > 0) || !out || !outlen ||
> include/linux/init.h:   int var = IS_ENABLED(config);                                   \
> include/linux/kconfig.h: * This is similar to IS_ENABLED(), but returns false when invoked from
> include/linux/kconfig.h:#define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
> include/linux/page-flags-layout.h: * the IS_ENABLED() macro.
> include/linux/raid/pq.h:#define IS_ENABLED(x) (x)
> lib/crypto/blake2s-generic.c:   WARN_ON(IS_ENABLED(DEBUG) &&
> lib/crypto/blake2s.c:   WARN_ON(IS_ENABLED(DEBUG) && !out);
> lib/crypto/chacha20poly1305-selftest.c: for (total_len = POLY1305_DIGEST_SIZE; IS_ENABLED(DEBUG_CHACHA20POLY1305_SLOW_CHUNK_TEST)
> lib/test_ubsan.c:                       #config, IS_ENABLED(config) ? "y" : "n");       \
> scripts/checkpatch.pl:# check for IS_ENABLED() without CONFIG_<FOO> ($rawline for comments too)
> scripts/checkpatch.pl:                       "IS_ENABLED($1) is normally used as IS_ENABLED(${CONFIG_}$1)\n" . $herecurr);
> scripts/checkpatch.pl:                           "Prefer IS_ENABLED(<FOO>) to ${CONFIG_}<FOO> || ${CONFIG_}<FOO>_MODULE\n" . $herecurr) &&
> scripts/checkpatch.pl:                          $fixed[$fixlinenr] = "\+#if IS_ENABLED($config)";
> tools/testing/scatterlist/linux/mm.h:#define IS_ENABLED(x) (0)
>
>

That's true.
The following looks okay to me:

IS_ENABLED(DEBUG)
IS_ENABLED(cfg)
IS_ENABLED(opt_name)
IS_ENABLED(option)
IS_ENABLED(DEBUG_PRINT_TRIE_GRAPHVIZ)
IS_ENABLED(config)
IS_ENABLED(cond)
IS_ENABLED(__BIG_ENDIAN)
IS_ENABLED(x)
IS_ENABLED(DEBUG_CHACHA20POLY1305_SLOW_CHUNK_TEST)

Adding a CONFIG_ in these would be wrong I think.
I will drop this patch.

Thank you,
Dwaipayan.