2023-09-28 20:47:42

by Joe Perches

Subject: Re: [PATCH] rust: Use awk instead of recent xargs

On Thu, 2023-09-28 at 20:21 +0000, Matthew Maurer wrote:
> `awk` is already required by the kernel build, and the `xargs` feature
> used in current Rust detection is not present in all `xargs` (notably,
> toybox based xargs, used in the Android kernel build).
[]
> diff --git a/rust/Makefile b/rust/Makefile
[]
> @@ -365,8 +365,7 @@ quiet_cmd_exports = EXPORTS $@
> cmd_exports = \
> $(NM) -p --defined-only $< \
> | grep -E ' (T|R|D) ' | cut -d ' ' -f 3 \
> - | xargs -Isymbol \
> - echo 'EXPORT_SYMBOL_RUST_GPL(symbol);' > $@
> + | awk 'NF {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$0}' > $@

Perhaps remove the cut as well and use $$3 instead of $$0 ?
Maybe integrate the grep as well.

2023-09-29 21:38:47

by David Laight

Subject: RE: [PATCH] rust: Use awk instead of recent xargs

From: Joe Perches
> Sent: 28 September 2023 21:33
>
> On Thu, 2023-09-28 at 20:21 +0000, Matthew Maurer wrote:
> > `awk` is already required by the kernel build, and the `xargs` feature
> > used in current Rust detection is not present in all `xargs` (notably,
> > toybox based xargs, used in the Android kernel build).
> []
> > diff --git a/rust/Makefile b/rust/Makefile
> []
> > @@ -365,8 +365,7 @@ quiet_cmd_exports = EXPORTS $@
> > cmd_exports = \
> > $(NM) -p --defined-only $< \
> > | grep -E ' (T|R|D) ' | cut -d ' ' -f 3 \
> > - | xargs -Isymbol \
> > - echo 'EXPORT_SYMBOL_RUST_GPL(symbol);' > $@
> > + | awk 'NF {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$0}' > $@
>
> Perhaps remove the cut as well and use $$3 instead of $$0 ?
> Maybe integrate the grep as well.

Or keep the grep and use a shell loop?
grep -E ' (T|R|D) ' | while read val flag symbol; do \
echo "EXPORT_SYMBOL_RUST_GPL($symbol);"; done

(The grep is typically much faster than a shell conditional.)

David

-
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2023-09-29 23:29:37

by Joe Perches

Subject: Re: [PATCH] rust: Use awk instead of recent xargs

On Fri, 2023-09-29 at 21:36 +0000, David Laight wrote:
> From: Joe Perches
> > Sent: 28 September 2023 21:33
> >
> > On Thu, 2023-09-28 at 20:21 +0000, Matthew Maurer wrote:
> > > `awk` is already required by the kernel build, and the `xargs` feature
> > > used in current Rust detection is not present in all `xargs` (notably,
> > > toybox based xargs, used in the Android kernel build).
> > []
> > > diff --git a/rust/Makefile b/rust/Makefile
> > []
> > > @@ -365,8 +365,7 @@ quiet_cmd_exports = EXPORTS $@
> > > cmd_exports = \
> > > $(NM) -p --defined-only $< \
> > > | grep -E ' (T|R|D) ' | cut -d ' ' -f 3 \
> > > - | xargs -Isymbol \
> > > - echo 'EXPORT_SYMBOL_RUST_GPL(symbol);' > $@
> > > + | awk 'NF {printf "EXPORT_SYMBOL_RUST_GPL(%s);\n",$$0}' > $@
> >
> > Perhaps remove the cut as well and use $$3 instead of $$0 ?
> > Maybe integrate the grep as well.
>
> Or keep the grep and use a shell loop?
> grep -E ' (T|R|D) ' | while read val flag symbol; do \
> echo "EXPORT_SYMBOL_RUST_GPL($symbol);"; done
>
> (The grep is typically much faster than a shell conditional.)
>

Bikeshed:

no grep just a single awk with whatever the appropriate syntax is like

awk '{ if ($$2 ~ /^[TRD]$/) { printf "EXPORT_SYMBOL_RUST(%s);\n", $$3 } }'