cargo: Add API version into dependency name

docs/markdown/Wrap-dependency-system-manual.md

@@ -316,11 +316,24 @@ foo-bar-1.0 = foo_bar_dep
 ```
 ### Cargo wraps
 
-Cargo subprojects automatically override the `<package_name>-rs` dependency name.
-`package_name` is defined in `[package] name = ...` section of the `Cargo.toml`
-and `-rs` suffix is added. That means the `.wrap` file should have
-`dependency_names = foo-rs` in their `[provide]` section when `Cargo.toml` has
-package name `foo`.
+Cargo subprojects automatically override the `<package_name>-<version>-rs` dependency
+name:
+- `package_name` is defined in `[package] name = ...` section of the `Cargo.toml`.
+- `version` is the API version deduced from `[package] version = ...` as follow:
+  * `x.y.z` -> 'x'
+  * `0.x.y` -> '0.x'
+  * `0.0.x` -> '0'
+  It allows to make different dependencies for uncompatible versions of the same
+  crate.
+- `-rs` suffix is added to distinguish from regular system dependencies, for
+  example `gstreamer-1.0` is a system pkg-config dependency and `gstreamer-0.22-rs`
+  is a Cargo dependency.
+
+That means the `.wrap` file should have `dependency_names = foo-1-rs` in their
+`[provide]` section when `Cargo.toml` has package name `foo` and version `1.2`.
+
+Note that the version component was added in Meson 1.4, previous versions were
+using `<package_name>-rs` format.
 
 Cargo subprojects require a toml parser. Python >= 3.11 have one built-in, older
 Python versions require either the external `tomli` module or `toml2json` program.
@@ -332,26 +345,26 @@ file like that:
 ...
 method = cargo
 [provide]
-dependency_names = foo-bar-rs
+dependency_names = foo-bar-0.1-rs
 ```
 
 Cargo features are exposed as Meson boolean options, with the `feature-` prefix.
 For example the `default` feature is named `feature-default` and can be set from
-the command line with `-Dfoo-rs:feature-default=false`. When a cargo subproject
+the command line with `-Dfoo-1-rs:feature-default=false`. When a cargo subproject
 depends on another cargo subproject, it will automatically enable features it
-needs using the `dependency('foo-rs', default_options: ...)` mechanism. However,
+needs using the `dependency('foo-1-rs', default_options: ...)` mechanism. However,
 unlike Cargo, the set of enabled features is not managed globally. Let's assume
-the main project depends on `foo-rs` and `bar-rs`, and they both depend on
-`common-rs`. The main project will first look up `foo-rs` which itself will
-configure `common-rs` with a set of features. Later, when `bar-rs` does a lookup
-for `common-rs` it has already been configured and the set of features cannot be
-changed. If `bar-rs` wants extra features from `common-rs`, Meson will error out.
+the main project depends on `foo-1-rs` and `bar-1-rs`, and they both depend on
+`common-1-rs`. The main project will first look up `foo-1-rs` which itself will
+configure `common-rs` with a set of features. Later, when `bar-1-rs` does a lookup
+for `common-1-rs` it has already been configured and the set of features cannot be
+changed. If `bar-1-rs` wants extra features from `common-1-rs`, Meson will error out.
 It is currently the responsability of the main project to resolve those
 issues by enabling extra features on each subproject:
 ```meson
 project(...,
   default_options: {
-    'common-rs:feature-something': true,
+    'common-1-rs:feature-something': true,
   },
 )
 ```

docs/markdown/snippets/cargo_dep_name.md

@@ -0,0 +1,19 @@
+## Cargo dependencies names now include the API version
+
+Cargo dependencies names are now in the format `<package_name>-<version>-rs`:
+- `package_name` is defined in `[package] name = ...` section of the `Cargo.toml`.
+- `version` is the API version deduced from `[package] version = ...` as follow:
+  * `x.y.z` -> 'x'
+  * `0.x.y` -> '0.x'
+  * `0.0.x` -> '0'
+  It allows to make different dependencies for uncompatible versions of the same
+  crate.
+- `-rs` suffix is added to distinguish from regular system dependencies, for
+  example `gstreamer-1.0` is a system pkg-config dependency and `gstreamer-0.22-rs`
+  is a Cargo dependency.
+
+That means the `.wrap` file should have `dependency_names = foo-1-rs` in their
+`[provide]` section when `Cargo.toml` has package name `foo` and version `1.2`.
+
+This is a breaking change (Cargo subprojects are still experimental), previous
+versions were using `<package_name>-rs` format.

mesonbuild/cargo/interpreter.py

@@ -162,9 +162,23 @@ class Dependency:
     package: str = ''
     default_features: bool = True
     features: T.List[str] = dataclasses.field(default_factory=list)
+    api: str = dataclasses.field(init=False)
 
     def __post_init__(self, name: str) -> None:
         self.package = self.package or name
+        # Extract wanted API version from version constraints.
+        api = set()
+        for v in self.version:
+            if v.startswith(('>=', '==')):
+                api.add(_version_to_api(v[2:].strip()))
+            elif v.startswith('='):
+                api.add(_version_to_api(v[1:].strip()))
+        if not api:
+            self.api = '0'
+        elif len(api) == 1:
+            self.api = api.pop()
+        else:
+            raise MesonException(f'Cannot determine minimum API version from {self.version}.')
 
     @classmethod
     def from_raw(cls, name: str, raw: manifest.DependencyV) -> Dependency:
@@ -351,8 +365,21 @@ def _load_manifests(subdir: str) -> T.Dict[str, Manifest]:
     return manifests
 
 
-def _dependency_name(package_name: str) -> str:
-    return package_name if package_name.endswith('-rs') else f'{package_name}-rs'
+def _version_to_api(version: str) -> str:
+    # x.y.z -> x
+    # 0.x.y -> 0.x
+    # 0.0.x -> 0
+    vers = version.split('.')
+    if int(vers[0]) != 0:
+        return vers[0]
+    elif len(vers) >= 2 and int(vers[1]) != 0:
+        return f'0.{vers[1]}'
+    return '0'
+
+
+def _dependency_name(package_name: str, api: str) -> str:
+    basename = package_name[:-3] if package_name.endswith('-rs') else package_name
+    return f'{basename}-{api}-rs'
 
 
 def _dependency_varname(package_name: str) -> str:
@@ -517,7 +544,7 @@ def _create_dependencies(cargo: Manifest, build: builder.Builder) -> T.List[mpar
             build.assign(
                 build.function(
                     'dependency',
-                    [build.string(_dependency_name(dep.package))],
+                    [build.string(_dependency_name(dep.package, dep.api))],
                     kw,
                 ),
                 _dependency_varname(dep.package),
@@ -559,7 +586,7 @@ def _create_dependencies(cargo: Manifest, build: builder.Builder) -> T.List[mpar
                     build.if_(build.not_in(build.identifier('f'), build.identifier('actual_features')), build.block([
                         build.function('error', [
                             build.string('Dependency'),
-                            build.string(_dependency_name(dep.package)),
+                            build.string(_dependency_name(dep.package, dep.api)),
                             build.string('previously configured with features'),
                             build.identifier('actual_features'),
                             build.string('but need'),
@@ -666,7 +693,7 @@ def _create_lib(cargo: Manifest, build: builder.Builder, crate_type: manifest.CR
             'override_dependency',
             build.identifier('meson'),
             [
-                build.string(_dependency_name(cargo.package.name)),
+                build.string(_dependency_name(cargo.package.name, _version_to_api(cargo.package.version))),
                 build.identifier('dep'),
             ],
         ),
@@ -674,7 +701,8 @@ def _create_lib(cargo: Manifest, build: builder.Builder, crate_type: manifest.CR
 
 
 def interpret(subp_name: str, subdir: str, env: Environment) -> T.Tuple[mparser.CodeBlockNode, KeyedOptionDictType]:
-    package_name = subp_name[:-3] if subp_name.endswith('-rs') else subp_name
+    # subp_name should be in the form "foo-0.1-rs"
+    package_name = subp_name.rsplit('-', 2)[0]
     manifests = _load_manifests(os.path.join(env.source_dir, subdir))
     cargo = manifests.get(package_name)
     if not cargo:

test cases/rust/22 cargo subproject/meson.build

@@ -1,6 +1,6 @@
 project('cargo subproject', 'c')
 
-foo_dep = dependency('foo-rs')
+foo_dep = dependency('foo-0-rs')
 exe = executable('app', 'main.c',
   dependencies: foo_dep,
 )

test cases/rust/22 cargo subproject/subprojects/extra-dep-1-rs/meson.build

@@ -7,4 +7,4 @@ d = declare_dependency(link_with: l,
   variables: {
     'features': 'default',
   })
-meson.override_dependency('extra-dep-rs', d)
+meson.override_dependency('extra-dep-1-rs', d)