Add a (working) windows compatibility mode that makes Bazel create hardlinks for links to writable files.

Curiously enough, the native Unix JNI wrapper already had a function for link(), but it wasn't on the Java interface.

build-runfiles is also updated accordingly.

--
MOS_MIGRATED_REVID=113029168

1 files changed, 8 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/vfs/UnixFileSystem.java b/src/main/java/com/google/devtools/build/lib/vfs/UnixFileSystem.java
index c0d41bd9c1..ee6af3fb39 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/UnixFileSystem.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/UnixFileSystem.java
@@ -374,7 +374,10 @@ public class UnixFileSystem extends AbstractFileSystemWithCustomStat {
       throws IOException {
     SymlinkImplementation strategy = computeSymlinkImplementation(linkPath, targetFragment);
     switch (strategy) {
-      case HARDLINK:  // TBD, fallthrough for now
+      case HARDLINK:
+        FilesystemUtils.link(targetFragment.toString(), linkPath.toString());
+        break;
+
       case JUNCTION:  // Junctions are emulated on Linux with symlinks, fall through
       case SYMLINK:
         synchronized (linkPath) {
@@ -492,6 +495,10 @@ public class UnixFileSystem extends AbstractFileSystemWithCustomStat {
         "Target is a non-writable file", linkPath, targetFragment);
   }
 
+  public SymlinkStrategy getSymlinkStrategy() {
+    return symlinkStrategy;
+  }
+
   @Override
   protected PathFragment readSymbolicLink(Path path) throws IOException {
     // Note that the default implementation of readSymbolicLinkUnchecked calls this method and thus