Flag to import external repositories in python import path

This flag will be used to turn off the feature until we
get support for --incompatible flag.

This flag is going to go away very fast, do not rely on it too much.

To be cherry-picked for 0.4.5 (#2472)

--
Change-Id: I2d3c79ae0c2c53089677573cffd40fa07e03c7e1
Reviewed-on: https://cr.bazel.build/9210
PiperOrigin-RevId: 149291628
MOS_MIGRATED_REVID=149291628

3 files changed, 24 insertions, 6 deletions

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 fa5e21942a..d1768e1611 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
@@ -48,6 +48,12 @@ public class BazelPythonConfiguration extends BuildConfiguration.Fragment {
       category = "version",
       help = "Local path to the Python3 executable.")
     public String python3Path;
+
+    @Option(name = "experimental_python_import_all_repositories",
+      defaultValue = "true",
+      category = "undocumented",
+      help = "Do not use.")
+    public boolean experimentalPythonImportAllRepositories;
   }
 
   /**
@@ -85,4 +91,8 @@ public class BazelPythonConfiguration extends BuildConfiguration.Fragment {
   public String getPython3Path() {
     return options.python3Path;
   }
+
+  public boolean getImportAllRepositories() {
+    return options.experimentalPythonImportAllRepositories;
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonSemantics.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonSemantics.java
index 06fe867fa0..a913927f8f 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonSemantics.java
@@ -144,7 +144,9 @@ public class BazelPythonSemantics implements PythonSemantics {
                   Substitution.of("%python_binary%", pythonBinary),
                   Substitution.of("%imports%", Joiner.on(":").join(imports)),
                   Substitution.of("%workspace_name%", ruleContext.getWorkspaceName()),
-                  Substitution.of("%is_zipfile%", "False")),
+                  Substitution.of("%is_zipfile%", "False"),
+                  Substitution.of("%import_all%",
+                      config.getImportAllRepositories() ? "True" : "False")),
               true));
     } else {
       Artifact zipFile = getPythonZipArtifact(ruleContext, executable);
@@ -160,7 +162,9 @@ public class BazelPythonSemantics implements PythonSemantics {
                   Substitution.of("%python_binary%", pythonBinary),
                   Substitution.of("%imports%", Joiner.on(":").join(imports)),
                   Substitution.of("%workspace_name%", ruleContext.getWorkspaceName()),
-                  Substitution.of("%is_zipfile%", "True")),
+                  Substitution.of("%is_zipfile%", "True"),
+                  Substitution.of("%import_all%",
+                      config.getImportAllRepositories() ? "True" : "False")),
               true));
 
       ruleContext.registerAction(
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/stub_template.txt b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/stub_template.txt
index 00ebcc51fc..0e28ce16f7 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/python/stub_template.txt
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/python/stub_template.txt
@@ -99,6 +99,13 @@ def CreateModuleSpace():
   zf.extractall(temp_dir)
   return os.path.join(temp_dir, ZIP_RUNFILES_DIRECTORY_NAME)
 
+# Returns repository roots to add to the import path.
+def GetRepositoriesImports(module_space, import_all):
+  if import_all:
+    repo_dirs = [os.path.join(module_space, d) for d in os.listdir(module_space)]
+    return [d for d in repo_dirs if os.path.isdir(d)]
+  return [os.path.join(module_space, "%workspace_name%")]
+
 def Main():
   args = sys.argv[1:]
 
@@ -111,10 +118,7 @@ def Main():
 
   python_imports = '%imports%'
   python_path_entries = CreatePythonPathEntries(python_imports, module_space)
-
-  repo_dirs = [os.path.join(module_space, d) for d in os.listdir(module_space)]
-  repositories = [d for d in repo_dirs if os.path.isdir(d)]
-  python_path_entries += repositories
+  python_path_entries += GetRepositoriesImports(module_space, %import_all%)
 
   old_python_path = os.environ.get('PYTHONPATH')
   python_path = os.pathsep.join(python_path_entries)