Merge pull request #31 from dtolnay/execplatform

Drop unneeded execution platforms

Author: dtolnay

README.md

@@ -52,7 +52,7 @@ $ buck2 build :rustc_ast[profile][llvm_passes] --show-output
 
 ## Configurations
 
-The following execution platforms are available for use with `--target-platforms`:
+The following platforms are available for use with `--target-platforms`:
 
 - `//platforms/stage1:library`
 - `//platforms/stage1:library-build-script`

platforms/BUCK

@@ -1,7 +1,7 @@
 load("@prelude//platforms:defs.bzl", "host_configuration")
-load(":defs.bzl", "execution_platforms", "platform")
+load(":defs.bzl", "execution_platform", "execution_platforms")
 
-platform(
+execution_platform(
     name = "host",
     constraint_values = [
         host_configuration.cpu,
@@ -14,13 +14,9 @@ execution_platforms(
     name = "execution",
     platforms = [
         ":host",
-        "//platforms/stage1:compiler",
         "//platforms/stage1:compiler-build-script",
-        "//platforms/stage1:library",
         "//platforms/stage1:library-build-script",
-        "//platforms/stage2:compiler",
         "//platforms/stage2:compiler-build-script",
-        "//platforms/stage2:library",
         "//platforms/stage2:library-build-script",
     ],
 )

platforms/defs.bzl

@@ -44,32 +44,45 @@ def _platform_impl(ctx: AnalysisContext) -> list[Provider]:
             label = str(platform_label),
             configuration = configuration,
         ),
-        ExecutionPlatformInfo(
+        TransitionInfo(impl = transition_impl),
+    ] + (
+        [ExecutionPlatformInfo(
             label = platform_label,
             configuration = configuration,
             executor_config = CommandExecutorConfig(
                 local_enabled = True,
                 remote_enabled = False,
                 use_windows_path_separators = use_windows_path_separators,
             ),
-        ),
-        TransitionInfo(impl = transition_impl),
-    ]
+        )] if ctx.attrs.execution_platform else []
+    )
+
+_platform_attrs = {
+    "base": attrs.option(attrs.dep(providers = [PlatformInfo]), default = None),
+    "constraint_values": attrs.list(attrs.configuration_label(), default = []),
+    # Configuration settings in this list are overwritten during a
+    # transition to this platform, whereas configuration settings not in
+    # this list are preserved.
+    "transition": attrs.list(attrs.configuration_label(), default = [
+        "//constraints:bootstrap-stage",
+        "//constraints:build-script",
+        "//constraints:opt-level",
+        "//constraints:workspace",
+    ]),
+}
 
-platform = rule(
+target_platform = rule(
     impl = _platform_impl,
-    attrs = {
-        "base": attrs.option(attrs.dep(providers = [PlatformInfo]), default = None),
-        "constraint_values": attrs.list(attrs.configuration_label(), default = []),
-        # Configuration settings in this list are overwritten during a
-        # transition to this platform, whereas configuration settings not in
-        # this list are preserved.
-        "transition": attrs.list(attrs.configuration_label(), default = [
-            "//constraints:bootstrap-stage",
-            "//constraints:build-script",
-            "//constraints:opt-level",
-            "//constraints:workspace",
-        ]),
+    attrs = _platform_attrs | {
+        "execution_platform": attrs.default_only(attrs.bool(default = False)),
+    },
+    is_configuration_rule = True,
+)
+
+execution_platform = rule(
+    impl = _platform_impl,
+    attrs = _platform_attrs | {
+        "execution_platform": attrs.default_only(attrs.bool(default = True)),
     },
     is_configuration_rule = True,
 )

platforms/stage1/BUCK

@@ -1,6 +1,6 @@
-load("//platforms:defs.bzl", "platform")
+load("//platforms:defs.bzl", "execution_platform", "target_platform")
 
-platform(
+target_platform(
     name = "library",
     base = "//platforms:host",
     constraint_values = [
@@ -12,7 +12,7 @@ platform(
     visibility = ["PUBLIC"],
 )
 
-platform(
+execution_platform(
     name = "library-build-script",
     base = ":library",
     constraint_values = [
@@ -22,7 +22,7 @@ platform(
     visibility = ["PUBLIC"],
 )
 
-platform(
+target_platform(
     name = "compiler",
     base = "//platforms:host",
     constraint_values = [
@@ -34,7 +34,7 @@ platform(
     visibility = ["PUBLIC"],
 )
 
-platform(
+execution_platform(
     name = "compiler-build-script",
     base = ":compiler",
     constraint_values = [

platforms/stage2/BUCK

@@ -1,6 +1,6 @@
-load("//platforms:defs.bzl", "platform")
+load("//platforms:defs.bzl", "execution_platform", "target_platform")
 
-platform(
+target_platform(
     name = "library",
     base = "//platforms:host",
     constraint_values = [
@@ -12,7 +12,7 @@ platform(
     visibility = ["PUBLIC"],
 )
 
-platform(
+execution_platform(
     name = "library-build-script",
     base = ":library",
     constraint_values = [
@@ -22,7 +22,7 @@ platform(
     visibility = ["PUBLIC"],
 )
 
-platform(
+target_platform(
     name = "compiler",
     base = "//platforms:host",
     constraint_values = [
@@ -34,7 +34,7 @@ platform(
     visibility = ["PUBLIC"],
 )
 
-platform(
+execution_platform(
     name = "compiler-build-script",
     base = ":compiler",
     constraint_values = [