jenkins installdir hack: Don't append /opt/<arch> to rootfs targets

This ensures that we end up with the same rootfs directory for -purecap
and -hybrid-for-purecap-rootfs targets. Fixes running:
```
env WORKSPACE=/tmp CHERIBUILD_ENABLE_HYBRID_FOR_PURECAP_ROOTFS_TARGETS=1 /usr/local/google/home/alexrichardson/cheri/cheribuild/tests/../jenkins-cheri-build.py --allow-more-than-one-target --build --test --cpu=default -p __run_everything__
```

Author: arichardson

pycheribuild/config/target_info.py

@@ -163,6 +163,7 @@ class AbstractProject(FileSystemUtils):
     _xtarget: "ClassVar[Optional[CrossCompileTarget]]" = None
     default_architecture: "ClassVar[Optional[CrossCompileTarget]]"
     needs_sysroot: "ClassVar[bool]"
+    is_rootfs_target: typing.ClassVar[bool] = False  # Whether this project installation directory is a rootfs dir
 
     auto_var_init: AutoVarInit  # Needed for essential_compiler_flags
     config: CheriConfig

pycheribuild/jenkins_utils.py

@@ -79,6 +79,8 @@ def expected_install_root(tgt: Target) -> Path:
 
     def expected_install_prefix(tgt: Target) -> Path:
         if install_prefix_arg is None:
+            if tgt.project_class.is_rootfs_target:
+                return Path("/")
             return default_install_prefix(tgt.xtarget, cheri_config)
         else:
             return install_prefix_arg

pycheribuild/projects/cross/cheribsd.py

@@ -632,6 +632,7 @@ class BuildFreeBSD(BuildFreeBSDBase):
     target: str = "freebsd"
     repository: GitRepository = GitRepository("https://github.com/freebsd/freebsd.git")
     needs_sysroot: bool = False  # We are building the full OS so we don't need a sysroot
+    is_rootfs_target: typing.ClassVar[bool] = True  # All derived classes are also rootfs targets
     # We still allow building FreeBSD for MIPS64. While the main branch no longer has support, this allows building
     # the stable/13 branch using cheribuild. However, MIPS is no longer included in ALL_SUPPORTED_FREEBSD_TARGETS.
     supported_architectures: "typing.ClassVar[tuple[CrossCompileTarget, ...]]" = (

pycheribuild/projects/cross/newlib.py

@@ -42,6 +42,7 @@ class BuildNewlib(CrossCompileAutotoolsProject):
     target = "newlib"
     make_kind = MakeCommandKind.GnuMake
     is_sdk_target = True
+    is_rootfs_target = True
     needs_sysroot = False  # We are building newlib so we don't need a sysroot
     add_host_target_build_config_options = False
     _configure_supports_libdir = False

pycheribuild/projects/cross/picolibc.py

@@ -39,6 +39,7 @@ class BuildPicoLibc(CrossCompileMesonProject):
     # Installing the native headers and libraries to <output>/local breaks other native project builds.
     native_install_dir = DefaultInstallDir.DO_NOT_INSTALL
     needs_sysroot = False
+    is_rootfs_target = True
     include_os_in_target_suffix = False  # Avoid adding -picolibc- as we are building picolibc here
     # ld.lld: error: -r and --gdb-index may not be used together
     add_gdb_index = False

pycheribuild/projects/project.py

@@ -1183,7 +1183,9 @@ def add_lto_build_options(self, ccinfo: CompilerInfo) -> bool:
     def rootfs_dir(self) -> Path:
         xtarget = self.crosscompile_target.get_rootfs_target()
         # noinspection PyProtectedMember
-        return self.target_info._get_rootfs_class(xtarget).get_install_dir(self, xtarget)
+        rootfs_cls: "type[AbstractProject]" = self.target_info._get_rootfs_class(xtarget)
+        assert rootfs_cls.is_rootfs_target
+        return rootfs_cls.get_install_dir(self, xtarget)
 
     @property
     def _no_overwrite_allowed(self) -> "Sequence[str]":

tests/test_argument_parsing.py

@@ -1493,29 +1493,25 @@ def test_jenkins_hack_hybrid_for_purecap_rootfs_prefix_none(monkeypatch):
     cheribsd_morello_purecap = _get_target_instance("cheribsd-morello-purecap", config, BuildCHERIBSD)
     # FIXME: we implicitly add /opt/morello-purecap for the rootfs dir here which does not make any sense
     assert cheribsd_morello_purecap.target_info.install_prefix_dirname == "morello-purecap"
-    assert cheribsd_morello_purecap.install_dir == Path("/tmp/tarball/opt/morello-purecap")
-    assert cheribsd_morello_purecap.rootfs_dir == Path("/tmp/tarball/opt/morello-purecap")
-    # FIXME: assert cheribsd_morello_purecap.install_dir == Path("/tmp/tarball")
-    # FIXME: assert cheribsd_morello_purecap.rootfs_dir == Path("/tmp/tarball")
+    assert cheribsd_morello_purecap.install_dir == Path("/tmp/tarball")
+    assert cheribsd_morello_purecap.rootfs_dir == Path("/tmp/tarball")
     # When building against the rootfs we do want the prefix though:
     gmp_morello_purecap = _get_target_instance("gmp-morello-purecap", config, Project)
     assert gmp_morello_purecap.crosscompile_target.is_cheri_purecap()
     assert gmp_morello_purecap.target_info.install_prefix_dirname == "morello-purecap"
     assert gmp_morello_purecap.install_dir == Path("/tmp/tarball/opt/morello-purecap")
-    assert gmp_morello_purecap.rootfs_dir == Path("/tmp/tarball/opt/morello-purecap")
-    # FIXME: gmp_morello_purecap.rootfs_dir == Path("/tmp/tarball")
+    assert gmp_morello_purecap.rootfs_dir == Path("/tmp/tarball")
     assert gmp_morello_purecap.rootfs_dir == cheribsd_morello_purecap.install_dir
 
     # The -hybrid-for-purecap-rootfs should install to the same rootfs but a different prefix:
     gmp_morello_hybrid_for_purecap = _get_target_instance("gmp-morello-hybrid-for-purecap-rootfs", config, Project)
     assert gmp_morello_hybrid_for_purecap.crosscompile_target.is_cheri_hybrid()
     assert gmp_morello_hybrid_for_purecap.target_info.install_prefix_dirname == "morello-hybrid"
     assert gmp_morello_hybrid_for_purecap.install_dir == Path("/tmp/tarball/opt/morello-hybrid")
+    # The rootfs should be the same as the gmp-purecap one:
+    assert gmp_morello_hybrid_for_purecap.rootfs_dir == gmp_morello_purecap.rootfs_dir
     assert gmp_morello_hybrid_for_purecap.rootfs_dir == cheribsd_morello_purecap.install_dir
-    # FIXME: rootfs should be the same as the gmp-purecap
-    # FIXME: assert gmp_morello_hybrid_for_purecap.rootfs_dir == gmp_morello_purecap.rootfs_dir
-    # FIXME: gmp_morello_hybrid_for_purecap.rootfs_dir == Path("/tmp/tarball")
-    assert gmp_morello_hybrid_for_purecap.rootfs_dir == Path("/tmp/tarball/opt/morello-purecap")
+    assert gmp_morello_hybrid_for_purecap.rootfs_dir == Path("/tmp/tarball")
 
 
 # Another regression test, explicitly overriding the installation directory triggered an assertion