libunwind: work around arm printf issue

When building for Arm, the following error is seen:
| ../../libunwind-1.6.2/src/arm/Gtrace.c:529:7: error: call to undeclared library function 'printf' with type 'int (const char *, ...)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
|       printf("XXX1\n");

Since every other reference to printf either has BSD or !linux then, I
think it's safe to assume this is not valid and a BSD ifdef can be
placed around this code.

Signed-off-by: Jon Mason <jdmason@kudzu.us>
---
 .../0007-Remove-undefined-printf.patch        | 32 +++++++++++++++++++
 .../libunwind/libunwind_1.6.2.bb              |  1 +
 2 files changed, 33 insertions(+)
 create mode 100644 meta/recipes-support/libunwind/libunwind/0007-Remove-undefined-printf.patch

On Tue, 21 Mar 2023 at 20:00, Jon Mason <jdmason@kudzu.us> wrote:
> +Upstream-Status: Pending

Please submit upstream first.

Alex

On Tue, Mar 21, 2023 at 12:00 PM Jon Mason <jdmason@kudzu.us> wrote:
>
> When building for Arm, the following error is seen:
> | ../../libunwind-1.6.2/src/arm/Gtrace.c:529:7: error: call to undeclared library function 'printf' with type 'int (const char *, ...)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> |       printf("XXX1\n");
>
> Since every other reference to printf either has BSD or !linux then, I
> think it's safe to assume this is not valid and a BSD ifdef can be
> placed around this code.
>

I think you can add
#include <stdio.h>
that should make the compiler happy, and you can easily upstream that
change too.

> Signed-off-by: Jon Mason <jdmason@kudzu.us>
> ---
>  .../0007-Remove-undefined-printf.patch        | 32 +++++++++++++++++++
>  .../libunwind/libunwind_1.6.2.bb              |  1 +
>  2 files changed, 33 insertions(+)
>  create mode 100644 meta/recipes-support/libunwind/libunwind/0007-Remove-undefined-printf.patch
>
> diff --git a/meta/recipes-support/libunwind/libunwind/0007-Remove-undefined-printf.patch b/meta/recipes-support/libunwind/libunwind/0007-Remove-undefined-printf.patch
> new file mode 100644
> index 000000000000..1826d8d72405
> --- /dev/null
> +++ b/meta/recipes-support/libunwind/libunwind/0007-Remove-undefined-printf.patch
> @@ -0,0 +1,32 @@
> +From ed4777e3200aadacfaf2b48e1cd6dec9da37c737 Mon Sep 17 00:00:00 2001
> +From: Jon Mason <jon.mason@arm.com>
> +Date: Tue, 21 Mar 2023 15:14:10 +0000
> +Subject: [PATCH] Remove undefined printf
> +
> +Seeing the following error when building with clang for Linux on Arm
> +| ../../libunwind-1.6.2/src/arm/Gtrace.c:529:7: error: call to undeclared library function 'printf' with type 'int (const char *, ...)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> +|       printf("XXX1\n");
> +
> +Based on other printf's in libunwind, this appears to not be used on
> +Linux (and appears to only be used for BSD).  So, add an ifdef around
> +this chunk to only be defined for BSD
> +
> +Upstream-Status: Pending
> +---
> + src/arm/Gtrace.c | 2 ++
> + 1 file changed, 2 insertions(+)
> +
> +diff --git a/src/arm/Gtrace.c b/src/arm/Gtrace.c
> +index 51fc281..fb73d87 100644
> +--- a/src/arm/Gtrace.c
> ++++ b/src/arm/Gtrace.c
> +@@ -526,7 +526,9 @@ tdep_trace (unw_cursor_t *cursor, void **buffer, int *size)
> +       break;
> +
> +     case UNW_ARM_FRAME_SYSCALL:
> ++#if defined(__FreeBSD__)
> +       printf("XXX1\n");
> ++#endif
> +       break;
> +
> +     default:
> diff --git a/meta/recipes-support/libunwind/libunwind_1.6.2.bb b/meta/recipes-support/libunwind/libunwind_1.6.2.bb
> index 716be9a452f4..74d7874f50bb 100644
> --- a/meta/recipes-support/libunwind/libunwind_1.6.2.bb
> +++ b/meta/recipes-support/libunwind/libunwind_1.6.2.bb
> @@ -5,6 +5,7 @@ SRC_URI = "http://download.savannah.nongnu.org/releases/libunwind/libunwind-${PV
>             file://0004-Fix-build-on-mips-musl.patch \
>             file://0005-ppc32-Consider-ucontext-mismatches-between-glibc-and.patch \
>             file://0006-Fix-for-X32.patch \
> +           file://0007-Remove-undefined-printf.patch \
>             "
>  SRC_URI:append:libc-musl = " file://musl-header-conflict.patch"
>
> --
> 2.30.2
>