gn: Add recipe

gn is a commonly used build tool to generate ninja files, used
in a lot of recipes e.g. chromium, qtwebengine, perfetto, hafnium etc.
these recipes come from different layers e.g. meta-qt6/meta-arm/meta-oe

since not all layers depend on meta-oe ( meta-arm does not ), its not
a possible option.

Given the usecases, putting it in core will benefit the ecosystem
and reduce some duplication. This recipe is taken from meta-arm

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 meta/conf/distro/include/maintainers.inc |  1 +
 meta/recipes-devtools/gn/gn_git.bb       | 46 ++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 meta/recipes-devtools/gn/gn_git.bb

> -----Original Message-----
> From: openembedded-core@lists.openembedded.org <openembedded-core@lists.openembedded.org> On Behalf Of Khem Raj via lists.openembedded.org
> Sent: den 27 september 2025 07:49
> To: openembedded-core@lists.openembedded.org
> Cc: Khem Raj <raj.khem@gmail.com>
> Subject: [OE-core] [PATCH] gn: Add recipe
> 
> gn is a commonly used build tool to generate ninja files, used
> in a lot of recipes e.g. chromium, qtwebengine, perfetto, hafnium etc.
> these recipes come from different layers e.g. meta-qt6/meta-arm/meta-oe
> 
> since not all layers depend on meta-oe ( meta-arm does not ), its not
> a possible option.
> 
> Given the usecases, putting it in core will benefit the ecosystem
> and reduce some duplication. This recipe is taken from meta-arm
> 
> Signed-off-by: Khem Raj <raj.khem@gmail.com>
> ---
>  meta/conf/distro/include/maintainers.inc |  1 +
>  meta/recipes-devtools/gn/gn_git.bb       | 46 ++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>  create mode 100644 meta/recipes-devtools/gn/gn_git.bb
> 
> diff --git a/meta/conf/distro/include/maintainers.inc b/meta/conf/distro/include/maintainers.inc
> index 0988bf50a72..85a9914469b 100644
> --- a/meta/conf/distro/include/maintainers.inc
> +++ b/meta/conf/distro/include/maintainers.inc
> @@ -224,6 +224,7 @@ RECIPE_MAINTAINER:pn-glibc-scripts = "Khem Raj <raj.khem@gmail.com>"
>  RECIPE_MAINTAINER:pn-glibc-testsuite = "Khem Raj <raj.khem@gmail.com>"
>  RECIPE_MAINTAINER:pn-gmp = "Khem Raj <raj.khem@gmail.com>"
>  RECIPE_MAINTAINER:pn-glslang = "Jose Quaresma <quaresma.jose@gmail.com>"
> +RECIPE_MAINTAINER:pn-gn = "Khem Raj <raj.khem@gmail.com>"
>  RECIPE_MAINTAINER:pn-gnome-desktop-testing = "Ross Burton <ross.burton@arm.com>"
>  RECIPE_MAINTAINER:pn-gnu-config = "Robert Yang <liezhi.yang@windriver.com>"
>  RECIPE_MAINTAINER:pn-gnu-efi = "Yi Zhao <yi.zhao@windriver.com>"
> diff --git a/meta/recipes-devtools/gn/gn_git.bb b/meta/recipes-devtools/gn/gn_git.bb
> new file mode 100644
> index 00000000000..abc81a9549f
> --- /dev/null
> +++ b/meta/recipes-devtools/gn/gn_git.bb
> @@ -0,0 +1,46 @@
> +SUMMARY = "GN is a meta-build system that generates build files for Ninja"
> +DEPENDS += "ninja-native"
> +
> +LICENSE = "BSD-3-Clause"
> +LIC_FILES_CHKSUM = "file://LICENSE;md5=0fca02217a5d49a14dfe2d11837bb34d"
> +
> +UPSTREAM_CHECK_COMMITS = "1"
> +
> +SRC_URI = "git://gn.googlesource.com/gn;protocol=https;branch=main"
> +SRCREV = "4ce861fc06ec87ff74eb6a17ebbd55e4755ebdeb"
> +PV = "0+git"
> +
> +B = "${WORKDIR}/build"
> +
> +# Map from our _OS strings to the GN's platform values.
> +def gn_platform(variable, d):
> +    os = d.getVar(variable)
> +    if "linux" in os:
> +        return "linux"
> +    elif "mingw" in os:
> +        return "mingw"
> +    else:
> +        return os
> +
> +do_configure[cleandirs] += "${B}"
> +do_configure() {
> +    python3 ${S}/build/gen.py \
> +        --platform=${@gn_platform("TARGET_OS", d)} \
> +        --out-path=${B} \
> +        --no-static-libstdc++ \
> +        --no-strip
> +}
> +

Add do_compile[progress] to catch the progress info from ninja:

do_compile[progress] = "outof:^\[(\d+)/(\d+)\]\s+"
> +do_compile() {
> +    ninja -C ${B} --verbose
> +}
> +
> +do_install() {
> +    install -d ${D}${bindir}
> +    install ${B}/gn ${D}${bindir}
> +}
> +
> +BBCLASSEXTEND = "native"
> +
> +COMPATIBLE_HOST = "^(?!riscv32).*"
> +CFLAGS += "-Wno-error=maybe-uninitialized"

//Peter

On Sat Sep 27, 2025 at 7:49 AM CEST, Khem Raj via lists.openembedded.org wrote:
> gn is a commonly used build tool to generate ninja files, used
> in a lot of recipes e.g. chromium, qtwebengine, perfetto, hafnium etc.
> these recipes come from different layers e.g. meta-qt6/meta-arm/meta-oe
>
> since not all layers depend on meta-oe ( meta-arm does not ), its not
> a possible option.
>
> Given the usecases, putting it in core will benefit the ecosystem
> and reduce some duplication. This recipe is taken from meta-arm
>
> Signed-off-by: Khem Raj <raj.khem@gmail.com>
> ---

Hi Khem,

It looks like the build is failing on some x86 builds:

ERROR: gn-0+git-r0 do_compile: Execution of '/srv/pokybuild/yocto-worker/musl-qemux86-64/build/build/tmp/work/x86-64-v3-poky-linux-musl/gn/0+git/temp/run.do_compile.3308486' failed with exit code 1
...
| cc1plus: error: '-Wformat-security' ignored without '-Wformat' [-Werror=format-security]

https://autobuilder.yoctoproject.org/valkyrie/#/builders/3/builds/2524
https://autobuilder.yoctoproject.org/valkyrie/#/builders/6/builds/2489
https://autobuilder.yoctoproject.org/valkyrie/#/builders/17/builds/2307
https://autobuilder.yoctoproject.org/valkyrie/#/builders/59/builds/2467

Thanks,
Mathieu

On Mon, Sep 29, 2025 at 4:15 AM Mathieu Dubois-Briand
<mathieu.dubois-briand@bootlin.com> wrote:
>
> On Sat Sep 27, 2025 at 7:49 AM CEST, Khem Raj via lists.openembedded.org wrote:
> > gn is a commonly used build tool to generate ninja files, used
> > in a lot of recipes e.g. chromium, qtwebengine, perfetto, hafnium etc.
> > these recipes come from different layers e.g. meta-qt6/meta-arm/meta-oe
> >
> > since not all layers depend on meta-oe ( meta-arm does not ), its not
> > a possible option.
> >
> > Given the usecases, putting it in core will benefit the ecosystem
> > and reduce some duplication. This recipe is taken from meta-arm
> >
> > Signed-off-by: Khem Raj <raj.khem@gmail.com>
> > ---
>
> Hi Khem,
>
> It looks like the build is failing on some x86 builds:
>
> ERROR: gn-0+git-r0 do_compile: Execution of '/srv/pokybuild/yocto-worker/musl-qemux86-64/build/build/tmp/work/x86-64-v3-poky-linux-musl/gn/0+git/temp/run.do_compile.3308486' failed with exit code 1
> ...
> | cc1plus: error: '-Wformat-security' ignored without '-Wformat' [-Werror=format-security]
>
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/3/builds/2524
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/6/builds/2489
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/17/builds/2307
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/59/builds/2467
>

yeah, please checkout v3, I sent earlier today

> Thanks,
> Mathieu
>
> --
> Mathieu Dubois-Briand, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
>