[Buildroot] [PATCH 1/1] package/dtc: fix include guards for older kernel/u-boot

[Yann E. MORIN <yann.morin.1998@free.fr>]

Lothar, All,

On 2018-10-08 13:51 +0200, Lothar Felten spake thusly:
> Patch dtc to accept libfdt include guards with and without leading underscore.
> A compiler warning is added to notify the user.

Please, do not add the warning. We should be as transparent as possible
when we add such workarounds.

It is not unseen that a configure script parses the output of gcc to
detect stuff, and expect the output to be either empty or a specific
regexp; adding this warning would break that.

Otherwise, the patch is simple enough, and looks OKish as a workaround.

Maybe we could suggest upstream to carry such a patch? And then, it
would be their call to add the warning or not.

Regards,
Yann E. MORIN.

> Signed-off-by: Lothar Felten <lothar.felten@gmail.com>
> ---
>  ...de-guards-for-older-kernel-u-boot-sources.patch | 42 ++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 package/dtc/0001-Fix-include-guards-for-older-kernel-u-boot-sources.patch
> 
> diff --git a/package/dtc/0001-Fix-include-guards-for-older-kernel-u-boot-sources.patch b/package/dtc/0001-Fix-include-guards-for-older-kernel-u-boot-sources.patch
> new file mode 100644
> index 0000000000..40cb0bdb2a
> --- /dev/null
> +++ b/package/dtc/0001-Fix-include-guards-for-older-kernel-u-boot-sources.patch
> @@ -0,0 +1,42 @@
> +From b1f8b84489c96465b63485b884238b61d31ca84d Mon Sep 17 00:00:00 2001
> +From: Lothar Felten <lothar.felten@gmail.com>
> +Date: Mon, 8 Oct 2018 13:29:44 +0200
> +Subject: [PATCH 1/1] Fix include guards for older kernel/u-boot sources
> +
> +Linux kernels before 4.17 and U-Boot versions before 2018.07 use libfdt include guards with leading underscores.
> +Those have been removed in dtc-1.4.7.
> +This patch handles both include guard types and allows the compilation of older Linux kernel and u-boot sources.
> +
> +Signed-off-by: Lothar Felten <lothar.felten@gmail.com>
> +---
> + libfdt/libfdt.h     | 4 ++++
> + libfdt/libfdt_env.h | 4 ++++
> + 2 files changed, 8 insertions(+)
> +
> +diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
> +index 830b77e..bef4566 100644
> +--- a/libfdt/libfdt.h
> ++++ b/libfdt/libfdt.h
> +@@ -1,3 +1,7 @@
> ++#ifdef _LIBFDT_H
> ++#warning "Please consider updating your kernel and/or u-boot version"
> ++#define LIBFDT_H
> ++#endif
> + #ifndef LIBFDT_H
> + #define LIBFDT_H
> + /*
> +diff --git a/libfdt/libfdt_env.h b/libfdt/libfdt_env.h
> +index eb20538..6a61e6a 100644
> +--- a/libfdt/libfdt_env.h
> ++++ b/libfdt/libfdt_env.h
> +@@ -1,3 +1,7 @@
> ++#ifdef _LIBFDT_ENV_H
> ++#warning "Please consider updating your kernel and/or u-boot version"
> ++#define LIBFDT_ENV_H
> ++#endif
> + #ifndef LIBFDT_ENV_H
> + #define LIBFDT_ENV_H
> + /*
> +-- 
> +2.11.0
> +
> -- 
> 2.11.0
> 

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