cargo: pick exact dependency version from Cargo.lock

A dependency might specify a version that is compatible with the one
in Cargo.lock, but not the exact same version.  Whenever Cargo.lock
contains the package, only use the pinned versions that can be used;
update the version in the manifest so that the correct API level is
used as well.

Originally by Xavier Claessens <xclaessens@netflix.com>, but
almost completely rewritten.

Author: bonzini

mesonbuild/cargo/interpreter.py

@@ -20,7 +20,7 @@
 from . import builder, version, cfg
 from .toml import load_toml
 from .manifest import Manifest, CargoLock, fixup_meson_varname
-from ..mesonlib import MesonException, MachineChoice
+from ..mesonlib import MesonException, MachineChoice, version_compare
 from .. import coredata, mlog
 from ..wrap.wrap import PackageDefinition
 
@@ -165,6 +165,19 @@ def _dep_package(self, dep: Dependency) -> PackageState:
             _, _, directory = _parse_git_url(dep.git, dep.branch)
             dep_pkg, _ = self._fetch_package_from_subproject(dep.package, directory)
         else:
+            # From all available versions from Cargo.lock, pick the most recent
+            # satisfying the constraints
+            if self.cargolock:
+                cargo_lock_pkgs = self.cargolock.named(dep.package)
+            else:
+                cargo_lock_pkgs = []
+            for cargo_pkg in cargo_lock_pkgs:
+                if all(version_compare(cargo_pkg.version, v) for v in dep.meson_version):
+                    dep.update_version(f'={cargo_pkg.version}')
+                    break
+            else:
+                if not dep.meson_version:
+                    raise MesonException(f'Cannot determine version of cargo package {dep.package}')
             dep_pkg, _ = self._fetch_package(dep.package, dep.api)
         return dep_pkg
 

mesonbuild/cargo/manifest.py

@@ -255,7 +255,7 @@ def api(self) -> str:
             elif v.startswith('='):
                 api.add(version.api(v[1:].strip()))
         if not api:
-            return '0'
+            return ''
         elif len(api) == 1:
             return api.pop()
         else:
@@ -281,6 +281,17 @@ def from_raw(cls, name: str, raw_depv: T.Union[raw.FromWorkspace, raw.Dependency
         raw_dep = _depv_to_dep(raw_depv)
         return cls.from_raw_dict(name, raw_dep, member_path, raw_ws_dep)
 
+    def update_version(self, v: str) -> None:
+        self.version = v
+        try:
+            delattr(self, 'api')
+        except AttributeError:
+            pass
+        try:
+            delattr(self, 'meson_version')
+        except AttributeError:
+            pass
+
 
 @dataclasses.dataclass
 class BuildTarget(T.Generic[_R]):