Add a --host_force_python flag

This allows using PY3 binaries in the HOST configuration.

--
Change-Id: I9603bb19a72cb3d0d731de5b35e135ce952cc545
Reviewed-on: https://bazel-review.googlesource.com/2401
MOS_MIGRATED_REVID=111311727

1 files changed, 17 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/python/PythonOptions.java b/src/main/java/com/google/devtools/build/lib/rules/python/PythonOptions.java
index 7ae76511f9..0b6deb2086 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/python/PythonOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/python/PythonOptions.java
@@ -31,6 +31,7 @@ public class PythonOptions extends FragmentOptions {
       super(PythonVersion.class, "Python version");
     }
   }
+
   @Option(name = "force_python",
       defaultValue = "null",
       category = "version",
@@ -38,6 +39,17 @@ public class PythonOptions extends FragmentOptions {
       help = "Overrides default_python_version attribute. Can be \"PY2\" or \"PY3\".")
   public PythonVersion forcePython;
 
+  @Option(
+    name = "host_force_python",
+    defaultValue = "null",
+    category = "version",
+    converter = PythonVersionConverter.class,
+    help =
+        "Overrides default_python_version attribute for the host configuration."
+            + " Can be \"PY2\" or \"PY3\"."
+  )
+  public PythonVersion hostForcePython;
+
   public PythonVersion getPythonVersion() {
     return (forcePython == null) ? DEFAULT_PYTHON_VERSION : forcePython;
   }
@@ -45,7 +57,11 @@ public class PythonOptions extends FragmentOptions {
   @Override
   public FragmentOptions getHost(boolean fallback) {
     PythonOptions hostPythonOpts = (PythonOptions) getDefault();
-    hostPythonOpts.forcePython = PythonVersion.PY2;
+    if (hostForcePython != null) {
+      hostPythonOpts.forcePython = hostForcePython;
+    } else {
+      hostPythonOpts.forcePython = PythonVersion.PY2;
+    }
     return hostPythonOpts;
   }
 }