Yank out the virtual exec root.

After this, only the virtual source root remains. Most `devirtualize()` calls can probably be removed at this point, but to be safe, I'll leave them until the virtual source root is also removed, so I don't have to distinguish between which calls are on output paths vs source paths.

PiperOrigin-RevId: 759670248
Change-Id: Ic8ee500e2b50fa5da0fcbbe0d080cdf4bd069060

Author: justinhorvitz

src/main/java/com/google/devtools/build/lib/analysis/BlazeDirectories.java

@@ -163,13 +163,13 @@ public Path getOutputBase() {
     return serverDirectories.getOutputBase();
   }
 
-  /** Returns the effective execution root, which may be virtualized. */
+  /** Returns the execution root base path with no workspace name fragment. */
   public Path getExecRootBase() {
     return serverDirectories.getExecRootBase();
   }
 
   /**
-   * Returns the local execution root of Google-internal Blaze. Virtualization is not respected.
+   * Returns the local execution root of Google-internal Blaze.
    *
    * <p>This method throws {@link NullPointerException} in Bazel. Use {@link #getExecRoot} instead.
    */
@@ -187,7 +187,7 @@ public Path getExecRoot(String workspaceName) {
   }
 
   /**
-   * Returns the local output path of Google-internal Blaze. Virtualization is not respected.
+   * Returns the local output path of Google-internal Blaze.
    *
    * <p>This method throws {@link NullPointerException} in Bazel. Use {@link #getOutputPath}
    * instead.

src/main/java/com/google/devtools/build/lib/analysis/ServerDirectories.java

@@ -121,11 +121,7 @@ public Path getOutputUserRoot() {
    * Parent of all execution roots.
    *
    * <p>By default, this is a folder called {@linkplain #EXECROOT execroot} in {@link
-   * #getOutputBase}. However, some {@link com.google.devtools.build.lib.vfs.FileSystem}
-   * implementations may choose to virtualize the execroot (in other words, it is not a real on-disk
-   * path, but one that the {@link com.google.devtools.build.lib.vfs.FileSystem} recognizes).
-   *
-   * <p>This is virtual if and only if {@link #getVirtualSourceRoot} is present.
+   * #getOutputBase}.
    */
   public Path getExecRootBase() {
     return execRootBase;
@@ -138,8 +134,6 @@ public Path getExecRootBase() {
    * <p>If present, the server's {@link com.google.devtools.build.lib.vfs.FileSystem} is responsible
    * for translating paths under this root to the actual requested {@code --package_path} for a
    * given command.
-   *
-   * <p>Present if and only if {@link #getExecRootBase} is virtualized.
    */
   @Nullable
   public Root getVirtualSourceRoot() {

src/main/java/com/google/devtools/build/lib/bazel/BazelFileSystemModule.java

@@ -30,7 +30,6 @@
 import com.google.devtools.build.lib.vfs.DigestHashFunction.DigestFunctionConverter;
 import com.google.devtools.build.lib.vfs.FileSystem;
 import com.google.devtools.build.lib.vfs.JavaIoFileSystem;
-import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.bazel.BazelHashFunctions;
 import com.google.devtools.build.lib.windows.WindowsFileSystem;
 import com.google.devtools.common.options.OptionsParsingException;
@@ -50,8 +49,7 @@ public class BazelFileSystemModule extends BlazeModule {
   }
 
   @Override
-  public ModuleFileSystem getFileSystem(
-      OptionsParsingResult startupOptions, PathFragment realExecRootBase)
+  public ModuleFileSystem getFileSystem(OptionsParsingResult startupOptions)
       throws AbruptExitException {
     BlazeServerStartupOptions options =
         checkNotNull(startupOptions.getOptions(BlazeServerStartupOptions.class));

src/main/java/com/google/devtools/build/lib/runtime/BlazeModule.java

@@ -92,11 +92,9 @@ public void globalInit(OptionsParsingResult startupOptions) throws AbruptExitExc
    * and {@link #blazeStartup}).
    *
    * @param startupOptions the server's startup options
-   * @param realExecRootBase absolute path fragment of the actual, underlying execution root
    */
   @Nullable
-  public ModuleFileSystem getFileSystem(
-      OptionsParsingResult startupOptions, PathFragment realExecRootBase)
+  public ModuleFileSystem getFileSystem(OptionsParsingResult startupOptions)
       throws AbruptExitException {
     return null;
   }
@@ -130,25 +128,15 @@ public abstract static class ModuleFileSystem {
      */
     abstract Optional<Root> virtualSourceRoot();
 
-    /**
-     * Present if this filesystem virtualizes the execroot folder. See {@link
-     * ServerDirectories#getExecRootBase}.
-     */
-    abstract Optional<Path> virtualExecRootBase();
-
     public static ModuleFileSystem createWithVirtualization(
-        FileSystem fileSystem, PathFragment virtualSourceRoot, PathFragment virtualExecRootBase) {
+        FileSystem fileSystem, PathFragment virtualSourceRoot) {
       return new AutoValue_BlazeModule_ModuleFileSystem(
-          fileSystem,
-          Optional.of(Root.fromPath(fileSystem.getPath(virtualSourceRoot))),
-          Optional.of(fileSystem.getPath(virtualExecRootBase)));
+          fileSystem, Optional.of(Root.fromPath(fileSystem.getPath(virtualSourceRoot))));
     }
 
     public static ModuleFileSystem create(FileSystem fileSystem) {
       return new AutoValue_BlazeModule_ModuleFileSystem(
-          fileSystem,
-          /* virtualSourceRoot= */ Optional.empty(),
-          /* virtualExecRootBase= */ Optional.empty());
+          fileSystem, /* virtualSourceRoot= */ Optional.empty());
     }
   }
 

src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java

@@ -1290,7 +1290,7 @@ private static BlazeRuntime newRuntime(
     PathFragment outputUserRoot = startupOptions.outputUserRoot;
     PathFragment installBase = startupOptions.installBase;
     PathFragment outputBase = startupOptions.outputBase;
-    PathFragment realExecRootBase = outputBase.getRelative(ServerDirectories.EXECROOT);
+    PathFragment execRootBase = outputBase.getRelative(ServerDirectories.EXECROOT);
 
     // Force JNI linking before the first real use of JNI to emit a helpful error message now that
     // we have the install base path handy.
@@ -1314,14 +1314,12 @@ private static BlazeRuntime newRuntime(
 
     FileSystem nativeFs = null;
     Optional<Root> virtualSourceRoot = Optional.empty();
-    Optional<Path> virtualExecRootBase = Optional.empty();
     for (BlazeModule module : blazeModules) {
-      ModuleFileSystem moduleFs = module.getFileSystem(options, realExecRootBase);
+      ModuleFileSystem moduleFs = module.getFileSystem(options);
       if (moduleFs != null) {
         Preconditions.checkState(nativeFs == null, "more than one module returns a file system");
         nativeFs = moduleFs.fileSystem();
         virtualSourceRoot = moduleFs.virtualSourceRoot();
-        virtualExecRootBase = moduleFs.virtualExecRootBase();
       }
     }
 
@@ -1415,7 +1413,7 @@ public void uncaughtException(Thread thread, Throwable throwable) {
     Path outputUserRootPath = fs.getPath(outputUserRoot);
     Path installBasePath = fs.getPath(installBase);
     Path outputBasePath = fs.getPath(outputBase);
-    Path execRootBasePath = virtualExecRootBase.orElseGet(() -> fs.getPath(realExecRootBase));
+    Path execRootBasePath = fs.getPath(execRootBase);
     Path workspaceDirectoryPath = null;
     if (!workspaceDirectory.equals(PathFragment.EMPTY_FRAGMENT)) {
       workspaceDirectoryPath = nativeFs.getPath(workspaceDirectory);

src/test/java/com/google/devtools/build/lib/buildtool/util/BuildIntegrationTestCase.java

@@ -254,7 +254,7 @@ public final void createFilesAndMocks() throws Exception {
             /* installBase= */ outputBase,
             /* outputBase= */ outputBase,
             /* outputUserRoot= */ outputBase,
-            /* execRootBase= */ getExecRootBase(),
+            /* execRootBase= */ outputBase.getRelative(ServerDirectories.EXECROOT),
             /* virtualSourceRoot= */ getVirtualSourceRoot(),
             // Arbitrary install base hash.
             /* installMD5= */ "83bc4458738962b9b77480bac76164a9");
@@ -332,10 +332,6 @@ protected Root getVirtualSourceRoot() {
     return null;
   }
 
-  protected Path getExecRootBase() {
-    return outputBase.getRelative(ServerDirectories.EXECROOT);
-  }
-
   protected void createRuntimeWrapper() throws Exception {
     if (runtimeWrapper != null) {
       cleanupInterningPools();

src/test/java/com/google/devtools/build/lib/skyframe/rewinding/RewindingTest.java

@@ -102,9 +102,7 @@ public void onTargetAnalyzed(TargetConfiguredEvent event) throws IOException {
       // Necessary due to the RepositoryHelpersHolder nulling above, simulates the effect of
       // TopLevelTargetReadyForSymlinkPlanting.
       FileSystemUtils.ensureSymbolicLink(
-          getExecRootBase()
-              .getChild(TestConstants.WORKSPACE_NAME)
-              .getRelative("external/bazel_tools"),
+          directories.getExecRoot(TestConstants.WORKSPACE_NAME).getRelative("external/bazel_tools"),
           getOutputBase().getRelative("external/bazel_tools"));
     }
   }