Hello Patrick, On Mon, 03 Mar 2025 13:10:59 +0100, Patrick Steinhardt <ps@xxxxxx> wrote: > Almost all of the tools we discover during the build process need to be > native programs. There are only a handful of exceptions, which typically > are programs whose paths we need to embed into the resulting executable > so that they can be found on the target system when Git executes. While > this distinction typically doesn't matter, it does start to matter when > considering cross-compilation where the build and target machines are > different. > > Meson supports cross-compilation via so-called machine files. These > machine files allow the user to override parameters for the build > machine, but also for the target machine when cross-compiling. Part of > the machine file is a section that allows the user to override the > location where binaries are to be found in the target system. The > following machine file would for example override the path of the POSIX > shell: > > [binaries] > sh = '/usr/xpg4/bin/sh' > > It can be handed over to Meson via `meson setup --cross-file`. > > We do not handle this correctly right now though because we don't know > to distinguish binaries for the build and target hosts at all. Address > this by explicitly passing the `native:` parameter to `find_program()`: > > - When set to `true`, we get binaries discovered on the build host. > > - When set to `false`, we get either the path specified in the > machine file. Or, if no machine file exists or it doesn't specify > the binary path, then we fall back to the binary discovered on the > build host. > > As mentioned, only a handful of binaries are not native: only the system > shell, Python and Perl need to be treated specially here. > > Signed-off-by: Patrick Steinhardt <ps@xxxxxx> > --- > Hi, > > this patch addresses the issue reported at [1], where it is impossible > to specify the shell, Python and Perl paths during cross-compilation > when using Meson. I still believe that is is a 'misuse' of the cross-file (as stated already here [1]) the given programs in cross-file are to be meant to run while cross-compiling (at compile time) and not on the target (e.g. it would be impossible to find a program (as the name find_program indicates) at compile/configure where the target layout is yet unknown.... I believe the correct solution is an extra configure option for cross-compile and a sane default (or find_program) in case of native build... Regards, Peter [1] https://public-inbox.org/git/20250210122603.5130e309@xxxxxxx/ > > The series is built on top of master at cb0ae672aea (A bit more post > -rc0, 2025-02-27) with junio/ps/build-meson-fixes-0130 at 9350423982a > (gitlab-ci: restrict maximum number of link jobs on Windows, 2025-02-26) > merged into it. > > Thanks! > > Patrick > > [1]: <20250209133027.64a865aa@xxxxxxx> > --- > Documentation/meson.build | 12 ++++----- > gitweb/meson.build | 2 +- > meson.build | 66 ++++++++++++++++++++++++++++++++++++----------- > templates/meson.build | 4 +-- > 4 files changed, 60 insertions(+), 24 deletions(-) > > diff --git a/Documentation/meson.build b/Documentation/meson.build > index 0a0f2bfa14a..63891fb4455 100644 > --- a/Documentation/meson.build > +++ b/Documentation/meson.build > @@ -207,9 +207,9 @@ manpages = { > > docs_backend = get_option('docs_backend') > if docs_backend == 'auto' > - if find_program('asciidoc', dirs: program_path, required: false).found() > + if find_program('asciidoc', dirs: program_path, native: true, required: false).found() > docs_backend = 'asciidoc' > - elif find_program('asciidoctor', dirs: program_path, required: false).found() > + elif find_program('asciidoctor', dirs: program_path, native: true, required: false).found() > docs_backend = 'asciidoctor' > else > error('Neither asciidoc nor asciidoctor were found.') > @@ -217,7 +217,7 @@ if docs_backend == 'auto' > endif > > if docs_backend == 'asciidoc' > - asciidoc = find_program('asciidoc', dirs: program_path) > + asciidoc = find_program('asciidoc', dirs: program_path, native: true) > asciidoc_html = 'xhtml11' > asciidoc_docbook = 'docbook' > xmlto_extra = [ ] > @@ -246,7 +246,7 @@ if docs_backend == 'asciidoc' > asciidoc_conf, > ] > elif docs_backend == 'asciidoctor' > - asciidoctor = find_program('asciidoctor', dirs: program_path) > + asciidoctor = find_program('asciidoctor', dirs: program_path, native: true) > asciidoc_html = 'xhtml5' > asciidoc_docbook = 'docbook5' > xmlto_extra = [ > @@ -284,7 +284,7 @@ elif docs_backend == 'asciidoctor' > ] > endif > > -xmlto = find_program('xmlto', dirs: program_path) > +xmlto = find_program('xmlto', dirs: program_path, native: true) > > cmd_lists = [ > 'cmds-ancillaryinterrogators.adoc', > @@ -405,7 +405,7 @@ if get_option('docs').contains('html') > pointing_to: 'git.html', > ) > > - xsltproc = find_program('xsltproc', dirs: program_path) > + xsltproc = find_program('xsltproc', dirs: program_path, native: true) > > user_manual_xml = custom_target( > command: asciidoc_common_options + [ > diff --git a/gitweb/meson.build b/gitweb/meson.build > index 89b403dc9de..88a54b4dc99 100644 > --- a/gitweb/meson.build > +++ b/gitweb/meson.build > @@ -1,5 +1,5 @@ > gitweb_config = configuration_data() > -gitweb_config.set_quoted('PERL_PATH', perl.full_path()) > +gitweb_config.set_quoted('PERL_PATH', target_perl.full_path()) > gitweb_config.set_quoted('CSSMIN', '') > gitweb_config.set_quoted('JSMIN', '') > gitweb_config.set_quoted('GIT_BINDIR', get_option('prefix') / get_option('bindir')) > diff --git a/meson.build b/meson.build > index 516207f9cfe..0a229f44199 100644 > --- a/meson.build > +++ b/meson.build > @@ -155,6 +155,37 @@ > # These machine files can be passed to `meson setup` via the `--native-file` > # option. > # > +# Cross compilation > +# ================= > +# > +# Machine files can also be used in the context of cross-compilation to > +# describe the target machine as well as the cross-compiler toolchain that > +# shall be used. An example machine file could look like the following: > +# > +# [binaries] > +# c = 'x86_64-w64-mingw32-gcc' > +# cpp = 'x86_64-w64-mingw32-g++' > +# ar = 'x86_64-w64-mingw32-ar' > +# windres = 'x86_64-w64-mingw32-windres' > +# strip = 'x86_64-w64-mingw32-strip' > +# exe_wrapper = 'wine64' > +# sh = 'C:/Program Files/Git for Windows/usr/bin/sh.exe' > +# > +# [host_machine] > +# system = 'windows' > +# cpu_family = 'x86_64' > +# cpu = 'x86_64' > +# endian = 'little' > +# > +# These machine files can be passed to `meson setup` via the `--cross-file` > +# option. > +# > +# Note that next to the cross-compiler toolchain, the `[binaries]` section is > +# also used to locate a couple of binaries that will be built into Git. This > +# includes `sh`, `python` and `perl`, so when cross-compiling Git you likely > +# want to set these binary paths in addition to the cross-compiler toolchain > +# binaries. > +# > # Subproject wrappers > # =================== > # > @@ -173,7 +204,7 @@ project('git', 'c', > # The version is only of cosmetic nature, so if we cannot find a shell yet we > # simply don't set up a version at all. This may be the case for example on > # Windows systems, where we first have to bootstrap the host environment. > - version: find_program('sh', required: false).found() ? run_command( > + version: find_program('sh', native: true, required: false).found() ? run_command( > 'GIT-VERSION-GEN', meson.current_source_dir(), '--format=@GIT_VERSION@', > capture: true, > check: true, > @@ -198,16 +229,18 @@ elif host_machine.system() == 'windows' > program_path = [ 'C:/Program Files/Git/bin', 'C:/Program Files/Git/usr/bin' ] > endif > > -cygpath = find_program('cygpath', dirs: program_path, required: false) > -diff = find_program('diff', dirs: program_path) > -git = find_program('git', dirs: program_path, required: false) > -sed = find_program('sed', dirs: program_path) > -shell = find_program('sh', dirs: program_path) > -tar = find_program('tar', dirs: program_path) > +cygpath = find_program('cygpath', dirs: program_path, native: true, required: false) > +diff = find_program('diff', dirs: program_path, native: true) > +git = find_program('git', dirs: program_path, native: true, required: false) > +sed = find_program('sed', dirs: program_path, native: true) > +shell = find_program('sh', dirs: program_path, native: true) > +tar = find_program('tar', dirs: program_path, native: true) > + > +target_shell = find_program('sh', dirs: program_path, native: false) > > # Sanity-check that programs required for the build exist. > foreach tool : ['cat', 'cut', 'grep', 'sort', 'tr', 'uname'] > - find_program(tool, dirs: program_path) > + find_program(tool, dirs: program_path, native: true) > endforeach > > script_environment = environment() > @@ -706,7 +739,7 @@ libgit_c_args = [ > '-DGIT_LOCALE_PATH="' + get_option('localedir') + '"', > '-DGIT_MAN_PATH="' + get_option('mandir') + '"', > '-DPAGER_ENV="' + get_option('pager_environment') + '"', > - '-DSHELL_PATH="' + fs.as_posix(shell.full_path()) + '"', > + '-DSHELL_PATH="' + fs.as_posix(target_shell.full_path()) + '"', > ] > libgit_include_directories = [ '.' ] > libgit_dependencies = [ ] > @@ -761,6 +794,7 @@ endif > build_options_config.set_quoted('X', executable_suffix) > > python = import('python').find_installation('python3', required: get_option('python')) > +target_python = find_program('python3', native: false, required: python.found()) > if python.found() > build_options_config.set('NO_PYTHON', '') > else > @@ -790,9 +824,11 @@ endif > # which we can do starting with Meson 1.5.0 and newer, or we have to > # match against the minor version. > if meson.version().version_compare('>=1.5.0') > - perl = find_program('perl', dirs: program_path, required: perl_required, version: '>=5.26.0', version_argument: '-V:version') > + perl = find_program('perl', dirs: program_path, native: true, required: perl_required, version: '>=5.26.0', version_argument: '-V:version') > + target_perl = find_program('perl', dirs: program_path, native: false, required: perl.found(), version: '>=5.26.0', version_argument: '-V:version') > else > - perl = find_program('perl', dirs: program_path, required: perl_required, version: '>=26') > + perl = find_program('perl', dirs: program_path, native: true, required: perl_required, version: '>=26') > + target_perl = find_program('perl', dirs: program_path, native: false, required: perl.found(), version: '>=26') > endif > perl_features_enabled = perl.found() and get_option('perl').allowed() > if perl_features_enabled > @@ -843,7 +879,7 @@ else > build_options_config.set('NO_PTHREADS', '1') > endif > > -msgfmt = find_program('msgfmt', dirs: program_path, required: false) > +msgfmt = find_program('msgfmt', dirs: program_path, native: true, required: false) > gettext_option = get_option('gettext').disable_auto_if(not msgfmt.found()) > if not msgfmt.found() and gettext_option.enabled() > error('Internationalization via libintl requires msgfmt') > @@ -1975,9 +2011,9 @@ foreach key, value : { > 'GIT_TEST_TEMPLATE_DIR': meson.project_build_root() / 'templates', > 'GIT_TEST_TEXTDOMAINDIR': meson.project_build_root() / 'po', > 'PAGER_ENV': get_option('pager_environment'), > - 'PERL_PATH': perl.found() ? perl.full_path() : '', > - 'PYTHON_PATH': python.found () ? python.full_path() : '', > - 'SHELL_PATH': shell.full_path(), > + 'PERL_PATH': target_perl.found() ? target_perl.full_path() : '', > + 'PYTHON_PATH': target_python.found () ? target_python.full_path() : '', > + 'SHELL_PATH': target_shell.full_path(), > 'TAR': tar.full_path(), > 'TEST_OUTPUT_DIRECTORY': test_output_directory, > 'TEST_SHELL_PATH': shell.full_path(), > diff --git a/templates/meson.build b/templates/meson.build > index 1faf9a44cea..02e6eebe80b 100644 > --- a/templates/meson.build > +++ b/templates/meson.build > @@ -1,6 +1,6 @@ > template_config = configuration_data() > -template_config.set('PERL_PATH', perl.found() ? fs.as_posix(perl.full_path()) : '') > -template_config.set('SHELL_PATH', fs.as_posix(shell.full_path())) > +template_config.set('PERL_PATH', target_perl.found() ? fs.as_posix(target_perl.full_path()) : '') > +template_config.set('SHELL_PATH', fs.as_posix(target_shell.full_path())) > template_config.set('GITWEBDIR', fs.as_posix(get_option('prefix') / get_option('datadir') / 'gitweb')) > > configure_file( > > --- > base-commit: af208620eecbe9b4655e06a28d5146a40738150e > change-id: 20250303-pks-meson-cross-compiling-7bad3078b9e8 >
