From 38b278944f7f0131d4eb2e1863009b7aabc39e2d Mon Sep 17 00:00:00 2001
From: Richard Levasseur <rlevasseur@google.com>
Date: Tue, 15 Nov 2022 09:49:20 -0800
Subject: [PATCH] Expose Python configuration fragments to Starlark for Bazel

Work towards #15897

PiperOrigin-RevId: 488684553
Change-Id: I6b439cf5b8fd75170e6647e4c76fa4ac8f72bdec
---
 .../devtools/build/lib/bazel/rules/python/BUILD      |  1 +
 .../bazel/rules/python/BazelPythonConfiguration.java | 12 ++++++++----
 .../build/lib/rules/python/PythonConfiguration.java  |  8 ++++++++
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BUILD b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BUILD
index 26da7689d97889..7493ceffc59c67 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BUILD
@@ -49,6 +49,7 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/util:os",
         "//src/main/java/com/google/devtools/build/lib/vfs:pathfragment",
         "//src/main/java/com/google/devtools/common/options",
+        "//src/main/java/net/starlark/java/annot",
         "//third_party:guava",
         "//third_party:jsr305",
     ],
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonConfiguration.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonConfiguration.java
index d4e5d2a569a3fc..537a212e4f02af 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonConfiguration.java
@@ -30,9 +30,12 @@
 import com.google.devtools.common.options.OptionDocumentationCategory;
 import com.google.devtools.common.options.OptionEffectTag;
 import com.google.devtools.common.options.OptionMetadataTag;
+import net.starlark.java.annot.StarlarkBuiltin;
+import net.starlark.java.annot.StarlarkMethod;
 
 /** Bazel-specific Python configuration. */
 @Immutable
+@StarlarkBuiltin(name = "bazel_py")
 @RequiresOptions(options = {BazelPythonConfiguration.Options.class, PythonOptions.class})
 public class BazelPythonConfiguration extends Fragment {
 
@@ -92,9 +95,7 @@ public static final class Options extends FragmentOptions {
                 + "is less likely to experience import name collisions.")
     public boolean experimentalPythonImportAllRepositories;
 
-     /**
-     * Make Python configuration options available for host configurations as well
-     */
+    /** Make Python configuration options available for host configurations as well */
     @Override
     public FragmentOptions getHost() {
       return clone(); // host options are the same as target options
@@ -151,8 +152,11 @@ public String getPythonPath() {
     return options.pythonPath == null ? "python" : options.pythonPath;
   }
 
+  @StarlarkMethod(
+      name = "python_import_all_repositories",
+      structField = true,
+      doc = "The value of the --experimental_python_import_all_repositories flag.")
   public boolean getImportAllRepositories() {
     return options.experimentalPythonImportAllRepositories;
   }
-
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/python/PythonConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/python/PythonConfiguration.java
index 596cf386f0991d..c60884146512dc 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/python/PythonConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/python/PythonConfiguration.java
@@ -126,6 +126,10 @@ public String getOutputDirectoryName() {
   }
 
   /** Returns whether to build the executable zip file for Python binaries. */
+  @StarlarkMethod(
+      name = "build_python_zip",
+      structField = true,
+      doc = "The effective value of --build_python_zip")
   public boolean buildPythonZip() {
     switch (buildPythonZip) {
       case YES:
@@ -157,6 +161,10 @@ public boolean useToolchains() {
     return useToolchains;
   }
 
+  @StarlarkMethod(
+      name = "default_to_explicit_init_py",
+      structField = true,
+      doc = "The value from the --incompatible_default_to_explicit_init_py flag")
   /**
    * Returns true if executable Python rules should only write out empty __init__ files to their
    * runfiles tree when explicitly requested via {@code legacy_create_init}.