env2mfile: Base cpu on DEB_HOST_GNU_CPU unless DEB_HOST_ARCH is special

`DEB_HOST_ARCH` encodes both the CPU family and the OS, so using it to
get the CPU type gives the wrong answer for non-Linux ports.

However, `DEB_HOST_GNU_CPU` gives less detailed information about the
CPU: it's `arm` for all 32-bit ARM CPUs, and doesn't distinguish between
the differing baselines of `armel` (ARMv5 softfloat) and `armhf`
(ARMv7 hardfloat).

When cross-compiling for x86_64 Linux, this changes the `cpu()` from
`amd64` to `x86_64`, which is consistent with the answer we get during
native builds on that architecture.

When cross-compiling for `ppc64el`, this changes the `cpu()` from
`ppc64el` to `ppc64`, which is a reasonable change but is still not
consistent with what we see during native builds (which is `ppc64le`):
see mesonbuild#13741 for that.

Signed-off-by: Simon McVittie <[email protected]>

mesonbuild/scripts/env2mfile.py

@@ -143,14 +143,20 @@ def get_args_from_envvars(infos: MachineInfo) -> None:
  if objcpp_link_args:
  infos.link_args['objcpp'] = objcpp_link_args
 
+# map from DEB_HOST_GNU_CPU to Meson machine.cpu_family()
 deb_cpu_family_map = {
  'mips64el': 'mips64',
  'i686': 'x86',
  'powerpc64le': 'ppc64',
 }
 
-deb_cpu_map = {
+# map from DEB_HOST_ARCH to Meson machine.cpu()
+deb_arch_cpu_map = {
  'armhf': 'arm7hlf',
+}
+
+# map from DEB_HOST_GNU_CPU to Meson machine.cpu()
+deb_cpu_map = {
  'mips64el': 'mips64',
  'powerpc64le': 'ppc64',
 }
@@ -212,8 +218,9 @@ def dpkg_architecture_to_machine_info(output: str, options: T.Any) -> MachineInf
  data['DEB_HOST_ARCH_OS'])
  host_cpu_family = deb_cpu_family_map.get(data['DEB_HOST_GNU_CPU'],
  data['DEB_HOST_GNU_CPU'])
- host_cpu = deb_cpu_map.get(data['DEB_HOST_ARCH'],
- data['DEB_HOST_ARCH'])
+ host_cpu = deb_arch_cpu_map.get(data['DEB_HOST_ARCH'],
+ deb_cpu_map.get(data['DEB_HOST_GNU_CPU'],
+ data['DEB_HOST_GNU_CPU']))
  host_endian = data['DEB_HOST_ARCH_ENDIAN']
 
  compilerstems = [('c', 'gcc'),

unittests/internaltests.py

@@ -1848,9 +1848,7 @@ def locate_path(program: str) -> T.List[str]:
  system='linux',
  subsystem='linux',
  kernel='linux',
- # TODO: In native builds we get x86_64, but in
- # cross-builds it's amd64
- cpu='TODO',
+ cpu='x86_64',
  cpu_family='x86_64',
  endian='little',
  ),
@@ -1983,8 +1981,7 @@ def locate_path(program: str) -> T.List[str]:
  # fail when kernel() is called.
  # https:/mesonbuild/meson/issues/13740
  kernel='TODO',
- # TODO: Currently hurd-i386, but should be i686
- cpu='TODO',
+ cpu='i686',
  cpu_family='x86',
  endian='little',
  ),
@@ -2039,8 +2036,7 @@ def locate_path(program: str) -> T.List[str]:
  system='kfreebsd',
  subsystem='kfreebsd',
  kernel='freebsd',
- # TODO: Currently kfreebsd-amd64 but should be x86_64
- cpu='TODO',
+ cpu='x86_64',
  cpu_family='x86_64',
  endian='little',
  ),
@@ -2150,8 +2146,7 @@ def locate_path(program: str) -> T.List[str]:
  system='linux',
  subsystem='linux',
  kernel='linux',
- # TODO: Currently ppc64el, but native builds have ppc64le,
- # and maybe it should be ppc64 in both cases?
+ # TODO: Currently ppc64, but native builds have ppc64le
  # https:/mesonbuild/meson/issues/13741
  cpu='TODO',
  cpu_family='ppc64',