| Message ID | 20250320003358.977774-1-javier.tia@linaro.org |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | doc: Mention `if [[ somecondition ]]` is not supported | expand |
On 3/20/25 1:33 AM, Javier Tia via lists.openembedded.org wrote: > I keep forgetting using `if [[ somecondition ]]` is not supported. > > Signed-off-by: Javier Tia <javier.tia@linaro.org> > --- > doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > index 415fbf6d6..5474e154f 100644 > --- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > +++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > @@ -1381,6 +1381,10 @@ To make use of this technique, you need the following things in place: > To call your modified version of the function as defined in your recipe, > call it as ``do_foo``. > > + .. note:: > + > + Conditional expression using ``[[ somecondition ]]`` is not supported. > + Do you know what the reason is for that limitation? The example above this git context is not really implying `[[ somecondition ]]` would be valid though. If I remember correctly, the shell functions are run by /bin/sh interpreter, so it depends on which shell you have configured by default in your system. Is it possible this is due to you being used to develop with bash where this is possible and having your Yocto build run with a different shell (e.g. dash, which doesn't seem to support that? c.f. https://manned.org/dash.1)? I think we should recommend people write POSIX-compliant shell functions and tasks rather no? Cheers, Quentin
On Tue, 2025-03-25 at 11:04 +0100, Quentin Schulz via lists.yoctoproject.org wrote: > > > On 3/20/25 1:33 AM, Javier Tia via lists.openembedded.org wrote: > > I keep forgetting using `if [[ somecondition ]]` is not supported. > > > > Signed-off-by: Javier Tia <javier.tia@linaro.org> > > --- > > doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > > index 415fbf6d6..5474e154f 100644 > > --- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > > +++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > > @@ -1381,6 +1381,10 @@ To make use of this technique, you need the following things in place: > > To call your modified version of the function as defined in your recipe, > > call it as ``do_foo``. > > > > + .. note:: > > + > > + Conditional expression using ``[[ somecondition ]]`` is not supported. > > + > > Do you know what the reason is for that limitation? > > The example above this git context is not really implying `[[ > somecondition ]]` would be valid though. > > If I remember correctly, the shell functions are run by /bin/sh > interpreter, so it depends on which shell you have configured by default > in your system. Is it possible this is due to you being used to develop > with bash where this is possible and having your Yocto build run with a > different shell (e.g. dash, which doesn't seem to support that? c.f. > https://manned.org/dash.1)? > > I think we should recommend people write POSIX-compliant shell functions > and tasks rather no? Bitbake parses the shell functions and our shell parser can't cope with certain syntax unfortunately. Cheers, Richard
Hi Richard, On 3/25/25 11:14 AM, Richard Purdie wrote: > On Tue, 2025-03-25 at 11:04 +0100, Quentin Schulz via lists.yoctoproject.org wrote: >> >> >> On 3/20/25 1:33 AM, Javier Tia via lists.openembedded.org wrote: >>> I keep forgetting using `if [[ somecondition ]]` is not supported. >>> >>> Signed-off-by: Javier Tia <javier.tia@linaro.org> >>> --- >>> doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 4 ++++ >>> 1 file changed, 4 insertions(+) >>> >>> diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst >>> index 415fbf6d6..5474e154f 100644 >>> --- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst >>> +++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst >>> @@ -1381,6 +1381,10 @@ To make use of this technique, you need the following things in place: >>> To call your modified version of the function as defined in your recipe, >>> call it as ``do_foo``. >>> >>> + .. note:: >>> + >>> + Conditional expression using ``[[ somecondition ]]`` is not supported. >>> + >> >> Do you know what the reason is for that limitation? >> >> The example above this git context is not really implying `[[ >> somecondition ]]` would be valid though. >> >> If I remember correctly, the shell functions are run by /bin/sh >> interpreter, so it depends on which shell you have configured by default >> in your system. Is it possible this is due to you being used to develop >> with bash where this is possible and having your Yocto build run with a >> different shell (e.g. dash, which doesn't seem to support that? c.f. >> https://manned.org/dash.1)? >> >> I think we should recommend people write POSIX-compliant shell functions >> and tasks rather no? > > Bitbake parses the shell functions and our shell parser can't cope with > certain syntax unfortunately. > Ah, I see. This happens before the shell even runs the code. Do we happen to have a list of things/syntax we cannot parse? I think it therefore deserves a bigger place than a small note, maybe e.g. a sub(sub...)section of limitations? Cheers, Quentin
On Tue, 2025-03-25 at 18:30 +0100, Quentin Schulz wrote: > Hi Richard, > > On 3/25/25 11:14 AM, Richard Purdie wrote: > > On Tue, 2025-03-25 at 11:04 +0100, Quentin Schulz via lists.yoctoproject.org wrote: > > > > > > > > > On 3/20/25 1:33 AM, Javier Tia via lists.openembedded.org wrote: > > > > I keep forgetting using `if [[ somecondition ]]` is not supported. > > > > > > > > Signed-off-by: Javier Tia <javier.tia@linaro.org> > > > > --- > > > > doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > > > > index 415fbf6d6..5474e154f 100644 > > > > --- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > > > > +++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > > > > @@ -1381,6 +1381,10 @@ To make use of this technique, you need the following things in place: > > > > To call your modified version of the function as defined in your recipe, > > > > call it as ``do_foo``. > > > > > > > > + .. note:: > > > > + > > > > + Conditional expression using ``[[ somecondition ]]`` is not supported. > > > > + > > > > > > Do you know what the reason is for that limitation? > > > > > > The example above this git context is not really implying `[[ > > > somecondition ]]` would be valid though. > > > > > > If I remember correctly, the shell functions are run by /bin/sh > > > interpreter, so it depends on which shell you have configured by default > > > in your system. Is it possible this is due to you being used to develop > > > with bash where this is possible and having your Yocto build run with a > > > different shell (e.g. dash, which doesn't seem to support that? c.f. > > > https://manned.org/dash.1)? > > > > > > I think we should recommend people write POSIX-compliant shell functions > > > and tasks rather no? > > > > Bitbake parses the shell functions and our shell parser can't cope with > > certain syntax unfortunately. > > > > Ah, I see. This happens before the shell even runs the code. Do we > happen to have a list of things/syntax we cannot parse? There are open bugs. I did recently run into backgrounding not working in the pseudo reproducer so I just used a separate script. Not sure we want to support background processes though. > I think it therefore deserves a bigger place than a small note, maybe > e.g. a sub(sub...)section of limitations? Patches welcome! Cheers, Richard
Hi Javier, On Thu Mar 20, 2025 at 1:33 AM CET, Javier Tia wrote: > I keep forgetting using `if [[ somecondition ]]` is not supported. > > Signed-off-by: Javier Tia <javier.tia@linaro.org> > --- > doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > index 415fbf6d6..5474e154f 100644 > --- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > +++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst > @@ -1381,6 +1381,10 @@ To make use of this technique, you need the following things in place: > To call your modified version of the function as defined in your recipe, > call it as ``do_foo``. > > + .. note:: > + > + Conditional expression using ``[[ somecondition ]]`` is not supported. > + > With these conditions met, your single recipe can freely choose between > the original function as defined in the class file and the modified > function in your recipe. If you do not set up these conditions, you are The documentation already says the following: The scripts are executed by ``/bin/sh``, which may not be a bash shell but might be something such as ``dash``. You should not use Bash-specific script (bashisms). I think [[ ]] is a bashism, or at least the POSIX shell spec clearly state to not use it[1]. I'm not sure the BitBake documentation should list all the shell syntax it does not support, as I expect there are quite a few. The codeparser, however, could be modified to try and detect the usage of [[ ]] and give a warning on such occurrences? [1]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_04 Antonin
diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst index 415fbf6d6..5474e154f 100644 --- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst +++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst @@ -1381,6 +1381,10 @@ To make use of this technique, you need the following things in place: To call your modified version of the function as defined in your recipe, call it as ``do_foo``. + .. note:: + + Conditional expression using ``[[ somecondition ]]`` is not supported. + With these conditions met, your single recipe can freely choose between the original function as defined in the class file and the modified function in your recipe. If you do not set up these conditions, you are
I keep forgetting using `if [[ somecondition ]]` is not supported. Signed-off-by: Javier Tia <javier.tia@linaro.org> --- doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 4 ++++ 1 file changed, 4 insertions(+)