[PATCH] meson: Work around configure_file(copy:true) deprecation

[Michal Prívozník]

On 4/20/23 14:07, Martin Kletzander wrote:
> On Thu, Mar 23, 2023 at 05:01:26PM +0100, Michal Privoznik wrote:
>> In our meson scripts, we use configure_file(copy:true) to copy
>> files from srcdir into builddir. However, as of meson-0.64.0,
>> this is deprecated [1] in favor of using:
>>
>>  fs = import('fs')
>>  fs.copyfile(in, out)
>>
>> Except, the submodule's new method wasn't introduced until
>> 0.64.0. And since we can't bump the minimal meson version we
>> require, we have to work with both: new and old versions.
>>
>> Now, the fun part: fs.copyfile() is not a drop in replacement as
>> it returns different type (a custom_target object). This is
>> incompatible with places where we store the configure_file()
>> retval in a variable to process it further.
>>
>> While we could just replace 'copy:true' with a dummy
>> 'configuration:...' (say 'configuration: configmake_conf') we
> 
> Actually, it would be even more clear that it is a dummy configuration
> if you used a dict instead of cfg_data.  Meson allows this in
> configure_file() according to the docs:
> 
> https://mesonbuild.com/Reference-manual_functions.html#configure_file
> 
>> can't do that for binary files (like src/fonts/ or src/images/).
>>
>> Therefore, places where we are not interested in the retval can
>> be switched to fs.copyfile() and places where we are interested
>> in the retval will just use a dummy 'configuration:'.
>>
>> Except, src/network/meson.build. In here we not just copy the
>> file but also specify alternative install dir and that's not
>> something that fs.copyfile() can handle. Yet, using 'copy: true'
>> is viewed wrong [2].
>>
>> 1:
>> https://mesonbuild.com/Release-notes-for-0-64-0.html#fscopyfile-to-replace-configure_filecopy-true
>> 2: https://github.com/mesonbuild/meson/pull/10042
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>> docs/css/meson.build    | 6 +++++-
>> docs/fonts/meson.build  | 6 +++++-
>> docs/images/meson.build | 6 +++++-
>> docs/js/meson.build     | 8 ++++++--
>> docs/logos/meson.build  | 6 +++++-
>> docs/meson.build        | 6 +++++-
>> meson.build             | 3 +++
>> src/locking/meson.build | 8 ++++----
>> src/network/meson.build | 2 +-
>> 9 files changed, 39 insertions(+), 12 deletions(-)
>>

>> diff --git a/src/network/meson.build b/src/network/meson.build
>> index d266bb225a..0888d1beac 100644
>> --- a/src/network/meson.build
>> +++ b/src/network/meson.build
>> @@ -84,7 +84,7 @@ if conf.has('WITH_NETWORK')
>>   configure_file(
>>     input: 'default.xml.in',
>>     output: '@BASENAME@',
>> -    copy: true,
>> +    configuration: configmake_conf,
> 
> As mentioned above I'd just use:
> 
> configuration: {},
> 
> here instead, but honestly, I haven't tried it.

That doesn't fly with meson:

Configuring default.xml using configuration
src/network/meson.build:84: WARNING: Got an empty configuration_data()
object and found no substitutions in the input file 'default.xml.in'. If
you want to copy a file to the build dir, use the 'copy:' keyword
argument added in 0.47.0

So it that's okay with you, I'd like to stick with this patch as is.

Michal