Add a migrator for moving from cross to native linux_aarch64 builds

conda_forge_tick/make_migrators.py

@@ -43,6 +43,7 @@
     CrossPythonMigrator,
     CrossRBaseMigrator,
     CrossRBaseWinMigrator,
+    CrossToNativeMigrator,
     DependencyUpdateMigrator,
     DuplicateLinesCleanup,
     ExtraJinja2KeysCleanup,
@@ -968,6 +969,27 @@ def add_cdt_migrator(
         migrators[-1].pr_limit = pr_limit
 
 
+def add_cross_to_native_migrator(
+    migrators: MutableSequence[Migrator],
+    gx: nx.DiGraph,
+):
+    with fold_log_lines("making cross-to-native migrator"):
+        migrators.append(
+            CrossToNativeMigrator(
+                total_graph=gx,
+                pr_limit=PR_LIMIT,
+                piggy_back_migrations=_make_mini_migrators_with_defaults(
+                    extra_mini_migrators=[YAMLRoundTrip()],
+                ),
+            )
+        )
+        pr_limit, _, _ = _compute_migrator_pr_limit(
+            migrators[-1],
+            PR_LIMIT,
+        )
+        migrators[-1].pr_limit = pr_limit
+
+
 def _make_version_migrator(
     gx: nx.DiGraph,
     dry_run: bool = False,
@@ -1036,6 +1058,8 @@ def initialize_migrators(
 
     add_cdt_migrator(migrators, gx)
 
+    add_cross_to_native_migrator(migrators, gx)
+
     pinning_migrators: list[Migrator] = []
     migration_factory(pinning_migrators, gx, _testing_frac=_testing_frac)
     create_migration_yaml_creator(

conda_forge_tick/migrators/__init__.py

@@ -23,6 +23,9 @@
     UpdateCMakeArgsWinMigrator,
     UpdateConfigSubGuessMigrator,
 )
+from .cross_to_native import (
+    CrossToNativeMigrator,
+)
 from .cstdlib import StdlibMigrator
 from .dep_updates import DependencyUpdateMigrator
 from .duplicate_lines import DuplicateLinesCleanup

conda_forge_tick/migrators/cross_to_native.py

@@ -0,0 +1,103 @@
+from pathlib import Path
+from typing import Any
+
+from conda_forge_tick.contexts import ClonedFeedstockContext, FeedstockContext
+from conda_forge_tick.migrators.core import Migrator
+from conda_forge_tick.migrators_types import (
+    AttrsTypedDict,
+    CondaForgeYamlContents,
+    MigrationUidTypedDict,
+)
+from conda_forge_tick.utils import (
+    yaml_safe_dump,
+    yaml_safe_load,
+)
+
+
+class CrossToNativeMigrator(Migrator):
+    name = "Cross-to-native Migrator"
+    rerender = True
+    migrator_version = 1
+
+    # platforms to migrate
+    _platforms = {"linux_aarch64"}
+    # build platforms where default = github_actions
+    _gha_platforms = {"linux_64"}
+
+    def _migrate_platform(self, platform: str, cfyaml: CondaForgeYamlContents) -> bool:
+        build_platform = cfyaml.get("build_platform", {}).get(platform)
+        if build_platform is None:
+            return False
+        provider = cfyaml.get("provider", {}).get(build_platform, "default")
+        return provider == "github_actions" or (
+            provider == "default" and build_platform in self._gha_platforms
+        )
+
+    def filter_not_in_migration(
+        self, attrs: AttrsTypedDict, not_bad_str_start: str = ""
+    ) -> bool:
+        if super().filter_not_in_migration(attrs, not_bad_str_start):
+            return True
+
+        # TODO: check if there are any relevant cross-targets
+        cfyaml = attrs.get("conda-forge.yml", {})
+        for platform in self._platforms:
+            if self._migrate_platform(platform, cfyaml):
+                return False
+
+        return True
+
+    def migrate(
+        self, recipe_dir: str, attrs: AttrsTypedDict, **kwargs: Any
+    ) -> MigrationUidTypedDict:
+        # Only v0 recipes are supported, the handful of v1 recipes is not worth the complexity.
+        recipe_file = next(
+            filter(
+                lambda x: x.exists(),
+                (Path(recipe_dir) / "recipe.yaml", Path(recipe_dir) / "meta.yaml"),
+            )
+        )
+        self.set_build_number(recipe_file)
+
+        cfyaml_path = Path(recipe_dir) / "../conda-forge.yml"
+        with open(cfyaml_path) as fp:
+            cfyaml = yaml_safe_load(fp)
+
+        for platform in self._platforms:
+            if not self._migrate_platform(platform, cfyaml):
+                continue
+
+            del cfyaml["build_platform"][platform]
+            cfyaml.setdefault("provider", {})[platform] = "default"
+
+        with open(cfyaml_path, "w") as fp:
+            yaml_safe_dump(cfyaml, fp)
+        return self.migrator_uid(attrs)
+
+    def pr_body(
+        self, feedstock_ctx: ClonedFeedstockContext, add_label_text: bool = True
+    ) -> str:
+        body = super().pr_body(feedstock_ctx)
+        body = body.format(
+            f"""\
+GitHub Actions provide native runners for {", ".join(self._platforms)} builds.
+This migrator will attempt to switch from cross-compilation to native build.
+"""
+        )
+        return body
+
+    def commit_message(self, feedstock_ctx: FeedstockContext) -> str:
+        return "Migrate cross-compilation to native build"
+
+    def pr_title(self, feedstock_ctx: FeedstockContext) -> str:
+        return "Migrate cross-compilation to native build"
+
+    def remote_branch(self, feedstock_ctx: FeedstockContext) -> str:
+        return f"cross-to-native-{self.migrator_version}"
+
+    def migrator_uid(self, attrs: AttrsTypedDict) -> MigrationUidTypedDict:
+        if self.name is None:
+            raise ValueError("name is None")
+        n = super().migrator_uid(attrs)
+        n["name"] = self.name
+        return n

tests/test_cross_to_native.py

@@ -0,0 +1,123 @@
+import networkx as nx
+import pytest
+from test_migrators import run_test_migration
+
+from conda_forge_tick.migrators import CrossToNativeMigrator
+
+TOTAL_GRAPH = nx.DiGraph()
+TOTAL_GRAPH.graph["outputs_lut"] = {}
+cross_to_native_migrator = CrossToNativeMigrator(total_graph=TOTAL_GRAPH)
+
+
+TEST_YAML = """\
+{% set version = "1.2.3" %}
+{% set build = @BUILD@ %}
+
+package:
+  name: test
+  version: {{ version }}
+
+build:
+  number: {{ build }}
+"""
+
+
+@pytest.mark.parametrize("provider", [None, "default", "github_actions"])
+def test_cross_to_native(tmp_path, provider: str | None):
+    """Test successfully migrating cross to native."""
+    input_yaml = """\
+build_platform:
+  linux_aarch64: linux_64
+  linux_ppc64le: linux_64
+  osx_arm64: osx_64
+  win_arm64: win_64
+"""
+    if provider is not None:
+        input_yaml += f"""\
+provider:
+  linux_64: {provider}
+"""
+
+    cfyaml = tmp_path / "conda-forge.yml"
+    cfyaml.write_text(input_yaml)
+
+    run_test_migration(
+        m=cross_to_native_migrator,
+        inp=TEST_YAML.replace("@BUILD@", "1"),
+        output=TEST_YAML.replace("@BUILD@", "2"),
+        prb="GitHub Actions provide native runners for linux_aarch64 builds",
+        kwargs={},
+        mr_out={
+            "migrator_name": "CrossToNativeMigrator",
+            "migrator_version": 1,
+            "name": "Cross-to-native Migrator",
+        },
+        tmp_path=tmp_path,
+    )
+
+    expected_providers = ""
+    if provider is not None:
+        expected_providers += f"  linux_64: {provider}\n"
+
+    assert (
+        cfyaml.read_text()
+        == f"""\
+build_platform:
+  linux_ppc64le: linux_64
+  osx_arm64: osx_64
+  win_arm64: win_64
+provider:
+{expected_providers}\
+  linux_aarch64: default
+"""
+    )
+
+
+@pytest.mark.parametrize("provider_platform", ["linux_64", "linux_aarch64"])
+def test_no_cross(tmp_path, provider_platform: str):
+    """Test package with no aarch64 build and with native aarch64 build."""
+    input_yaml = f"""\
+provider:
+  {provider_platform}: default
+"""
+
+    cfyaml = tmp_path / "conda-forge.yml"
+    cfyaml.write_text(input_yaml)
+
+    run_test_migration(
+        m=cross_to_native_migrator,
+        inp=TEST_YAML.replace("@BUILD@", "1"),
+        output="",
+        prb=None,
+        kwargs={},
+        mr_out=None,
+        tmp_path=tmp_path,
+        should_filter=True,
+    )
+
+
+def test_azure(tmp_path):
+    """Test package using non-GHA runner."""
+    input_yaml = """\
+build_platform:
+  linux_aarch64: linux_64
+  linux_ppc64le: linux_64
+  osx_arm64: osx_64
+  win_arm64: win_64
+provider:
+  linux_64: azure
+"""
+
+    cfyaml = tmp_path / "conda-forge.yml"
+    cfyaml.write_text(input_yaml)
+
+    run_test_migration(
+        m=cross_to_native_migrator,
+        inp=TEST_YAML.replace("@BUILD@", "1"),
+        output="",
+        prb=None,
+        kwargs={},
+        mr_out=None,
+        tmp_path=tmp_path,
+        should_filter=True,
+    )