commit 1f332e0c33ba98e82a5ba32c4e7c298a4ac99eff
author juliexxia <juliexxia@google.com> Wed Oct 31 14:20:55 2018 -0700
committer Copybara-Service <copybara-piper@google.com> Wed Oct 31 14:22:30 2018 -0700
tree d98174add1c621c160cce6023f5bc50d1e7a5a35
parent 7f4f3ce2b924934043babb97c22ee163926c35d1

Allow starlark rules to be build settings.

For skylark rules that are declared build settings, we auto-add a nonconfigurable build_setting_default attribute which must be set on a per target basis. We also add access to the build setting value via the rule context object. All of this functionality is hidden behind the --experimental_build_setting_api flag which by default is flipped off.

This includes:
- Add a build_setting parameter to starlark rule construction.
- If a starlark rule sets the build_setting parameter, auto-add a mandatory 'build_setting_default' attribute of the same type.
- Allow the value of a build setting skylark rules to be accessed via ctx.build_setting_value.
- Get rid of BuildSettingDescriptor since we don't need both it and BuildSetting.
- Add the --experimental_build_setting_api flag to SkylarkSemantics flags.

Work towards issue #5577

PiperOrigin-RevId: 219537101

src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java
index db78fb1..4580e2e 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java
@@ -43,6 +43,7 @@
         SkylarkSemantics::experimentalAnalysisTestingImprovements),
     EXPERIMENTAL_ENABLE_ANDROID_MIGRATION_APIS(
         SkylarkSemantics::experimentalEnableAndroidMigrationApis),
+    EXPERIMENTAL_BUILD_SETTING_API(SkylarkSemantics::experimentalBuildSettingApi),
     EXPERIMENTAL_PLATFORM_API(SkylarkSemantics::experimentalPlatformsApi),
     INCOMPATIBLE_DISABLE_OBJC_PROVIDER_RESOURCES(
         SkylarkSemantics::incompatibleDisableObjcProviderResources),
@@ -109,6 +110,8 @@
   // <== Add new options here in alphabetic order ==>
   public abstract boolean experimentalAnalysisTestingImprovements();
 
+  public abstract boolean experimentalBuildSettingApi();
+
   public abstract List<String> experimentalCcSkylarkApiEnabledPackages();
 
   public abstract boolean experimentalEnableAndroidMigrationApis();
@@ -193,6 +196,7 @@
       builder()
           // <== Add new options here in alphabetic order ==>
           .experimentalAnalysisTestingImprovements(false)
+          .experimentalBuildSettingApi(false)
           .experimentalCcSkylarkApiEnabledPackages(ImmutableList.of())
           .experimentalEnableAndroidMigrationApis(false)
           .experimentalEnableRepoMapping(false)
@@ -236,6 +240,8 @@
     // <== Add new options here in alphabetic order ==>
     public abstract Builder experimentalAnalysisTestingImprovements(boolean value);
 
+    public abstract Builder experimentalBuildSettingApi(boolean value);
+
     public abstract Builder experimentalCcSkylarkApiEnabledPackages(List<String> value);
 
     public abstract Builder experimentalEnableAndroidMigrationApis(boolean value);