bug#47325: newlib-nano: are lib names wrong?

bug#47325: newlib-nano: are lib names wrong?

[Nicolò Balzarotti]

Hi guix!

A program I'm packaging requires newlib-nano, but when building, the
linker fails to find g_nano and c_nano.

I found out those names are taken from the nano.specs file we install
> cat $(guix build newlib-nano)/arm-none-eabi/lib/nano.specs | grep -- -l

-lc_nano
%{specs=rdimon.specs:-lrdimon_nano} %{specs=nosys.specs:-lnosys}
%(nano_link) %:replace-outfile(-lc -lc_nano) %:replace-outfile(-lg -lg_nano)
%:replace-outfile(-lrdimon -lrdimon_nano) %:replace-outfile(-lstdc++ -lstdc++_nano)
%:replace-outfile(-lsupc++ -lsupc++_nano)
%{!shared:%{g*:-lg_nano} %{!p:%{!pg:-lc_nano}}%{p:-lc_p}%{pg:-lc_p}}

However, those files are missing:
> ls $(guix build newlib-nano)/arm-none-eabi/lib/ | grep lib

libc.a
libg.a
libgloss-linux.a
libm.a
libnosys.a
librdimon.a
librdimon-v2m.a
librdpmon.a

I was able to build the program by modifing the .specs file with:

(add-after 'install 'remove-suffix
           (lambda* (#:key outputs #:allow-other-keys)
             (substitute*
                 (string-append
                  (assoc-ref outputs "out")
                  "/arm-none-eabi/lib/nano.specs")
               (("_nano") ""))
             #t))

But reading online, it seems the _nano is a common suffix.  Should we
rename the output libs?  Should we symlink?  I know nothing about this,
but it might be a bug.

Thanks! Nicolò

bug#47325: newlib-nano: are lib names wrong?

[Morgan Smith]

Hello Nicolò,

This is definitely a bug that I encountered today. I'm convinced it's a
bug because I came across this page that says so:
https://newlib.sourceware.narkive.com/kfT8XDEe/building-libc-nano-and-libg-nano

The git repo it links to has the following shell function. I think we
should emulate its behavior.

(On a slightly unrelated note, can someone PLEASE accept my patch in bug
44750 for a different arm-none-eabi issue. It's desperately needed.)

copyNanoLibraries() {
	(
	source="${1}"
	destination="${2}"
	messageA "\"nano\" libraries copy"
	multilibs=$("${destination}/bin/${target}-gcc" -print-multi-lib)
	sourcePrefix="${source}/${target}/lib"
	destinationPrefix="${destination}/${target}/lib"
	for multilib in ${multilibs}; do
		multilib="${multilib%%;*}"
		sourceDirectory="${sourcePrefix}/${multilib}"
		destinationDirectory="${destinationPrefix}/${multilib}"
		mkdir -p "${destinationDirectory}"
		cp "${sourceDirectory}/libc.a" "${destinationDirectory}/libc_nano.a"
		cp "${sourceDirectory}/libg.a" "${destinationDirectory}/libg_nano.a"
		cp "${sourceDirectory}/librdimon.a" "${destinationDirectory}/librdimon_nano.a"
		cp "${sourceDirectory}/libstdc++.a" "${destinationDirectory}/libstdc++_nano.a"
		cp "${sourceDirectory}/libsupc++.a" "${destinationDirectory}/libsupc++_nano.a"
	done

	mkdir -p "${destination}/${target}/include/newlib-nano"
	cp "${source}/${target}/include/newlib.h" "${destination}/${target}/include/newlib-nano"

	if [ "${keepBuildFolders}" = "n" ]; then
		messageB "\"nano\" libraries remove install folder"
		maybeDelete "${top}/${buildNative}/${nanoLibraries}"
	fi
	)
}

bug#47325: [PATCH] gnu: newlib-nano: Fix nano lib and header paths

[Morgan.J.Smith]

From: Morgan Smith <Morgan.J.Smith@outlook.com>

* gnu/packages/embedded.scm (newlib-nano-arm-none-eabi)[arguments]: Hard link
library files from *.a to *_nano.a. Hard link newlib.h to a common location.
---

I CC'd Efraim because they commited my last gcc-arm-none-eabi patch. I hope
that's ok. I'm not really sure who is responsible for this toolchain.

I successfully compiled some QMK firmware using this patch, something that
failed previously.


 gnu/packages/embedded.scm | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/embedded.scm b/gnu/packages/embedded.scm
index a3f1d85580..ea5bfdbdd1 100644
--- a/gnu/packages/embedded.scm
+++ b/gnu/packages/embedded.scm
@@ -8,6 +8,7 @@
 ;;; Copyright © 2020 Marius Bakke <mbakke@fastmail.com>
 ;;; Copyright © 2020 Björn Höfling <bjoern.hoefling@bjoernhoefling.de>
 ;;; Copyright © 2021 Julien Lepiller <julien@lepiller.eu>
+;;; Copyright © 2021 Morgan Smith <Morgan.J.Smith@outlook.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -229,7 +230,40 @@ (define-public newlib-nano-arm-none-eabi
            "--enable-lite-exit"
            "--enable-newlib-global-atexit"
            "--enable-newlib-nano-formatted-io"
-           "--disable-nls"))))
+           "--disable-nls"))
+       ((#:phases phases)
+        `(modify-phases ,phases
+           ;; XXX: Most arm toolchains offer both *.a and *_nano.a as newlib
+           ;; and newlib-nano respectively.  The headers are usually
+           ;; arm-none-eabi/include/newlib.h for newlib and
+           ;; arm-none-eabi/include/newlib-nano/newlib.h for newlib-nano.  We
+           ;; have two different toolchain packages for each which works but
+           ;; is a little strange.
+           (add-after 'install 'hardlink-newlib
+             (lambda* (#:key outputs #:allow-other-keys)
+               (let ((out (assoc-ref outputs "out")))
+                 ;; The nano.specs file says that newlib-nano files should end
+                 ;; in "_nano.a" instead of just ".a".  Note that this applies
+                 ;; to all the multilib folders too.
+                 (for-each
+                  (lambda (file)
+                    (link file
+                          (string-append
+                           ;; Strip ".a" off the end
+                           (substring file 0 (- (string-length file) 2))
+                           ;; Add "_nano.a" onto the end
+                           "_nano.a")))
+                  (find-files
+                   out
+                   "^(libc.a|libg.a|librdimon.a|libstdc\\+\\+.a|libsupc\\+\\+.a)$"))
+
+                 ;; newlib.h is usually in this location instead so both
+                 ;; newlib and newlib-nano can be in the toolchain at the same
+                 ;; time
+                 (mkdir (string-append out "/arm-none-eabi/include/newlib-nano"))
+                 (link (string-append out "/arm-none-eabi/include/newlib.h")
+                       (string-append out "/arm-none-eabi/include/newlib-nano/newlib.h"))
+                 #t)))))))
     (synopsis "Newlib variant for small systems with limited memory")))
 
 \f
-- 
2.31.1

bug#47325: [PATCH] gnu: newlib-nano: Fix nano lib and header paths

[Efraim Flashner]

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On Thu, Apr 08, 2021 at 09:02:20AM -0400, Morgan.J.Smith@outlook.com wrote:
> From: Morgan Smith <Morgan.J.Smith@outlook.com>
> 
> * gnu/packages/embedded.scm (newlib-nano-arm-none-eabi)[arguments]: Hard link
> library files from *.a to *_nano.a. Hard link newlib.h to a common location.
> ---
> 
> I CC'd Efraim because they commited my last gcc-arm-none-eabi patch. I hope
> that's ok. I'm not really sure who is responsible for this toolchain.
> 
> I successfully compiled some QMK firmware using this patch, something that
> failed previously.
> 

No one is really in charge of the cross toolchains, it's more of when it
becomes relevant to someone and it's time to fix something.

It looks good to me, I made a small change, changing link to symlink and
made the link relative. I thought about factoring out 'lib' or '.a' from
the find-files but ultimately decided against it, I think it's probably
easier to read as-is.

Patch pushed! Feel free to tag me on other ones like this too.

-- 
Efraim Flashner   <efraim@flashner.co.il>   אפרים פלשנר
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