Use JavaIoFileSystem during the bootstrapping, removing JNI compilation.

Another step towards no C++ compilation outside of Bazel for bootstrapping.

--
MOS_MIGRATED_REVID=112399835

1 files changed, 4 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index 84c7da2455..79792665d5 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -987,6 +987,10 @@ public final class BlazeRuntime {
   }
 
   private static FileSystem fileSystemImplementation() {
+    if ("0".equals(System.getProperty("io.bazel.UnixFileSystem"))) {
+      // Ignore UnixFileSystem, to be used for bootstrapping.
+      return new JavaIoFileSystem();
+    }
     // The JNI-based UnixFileSystem is faster, but on Windows it is not available.
     return OS.getCurrent() == OS.WINDOWS ? new JavaIoFileSystem() : new UnixFileSystem();
   }