Tolerate "..." as the base filename for the fdo profile.

This is fragile, and there might be other places in the codebase this issue occurs.

--
MOS_MIGRATED_REVID=97784977

3 files changed, 21 insertions, 5 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java
index 9d4818ef24..23ee8f9e94 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java
@@ -34,6 +34,7 @@ import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.packages.Type;
 import com.google.devtools.build.lib.syntax.Label;
 import com.google.devtools.build.lib.syntax.Label.SyntaxException;
+import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.view.config.crosstool.CrosstoolConfig;
 
@@ -150,6 +151,12 @@ public class CppConfigurationLoader implements ConfigurationFragmentFactory {
       }
     } else {
       fdoZip = directories.getWorkspace().getRelative(cppOptions.fdoOptimize);
+      try {
+        // We don't check for file existence, but at least the filename should be well-formed.
+        FileSystemUtils.checkBaseName(fdoZip.getBaseName());
+      } catch (IllegalArgumentException e) {
+        throw new InvalidConfigurationException(e);
+      }
     }
 
     Label ccToolchainLabel;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/FdoSupport.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/FdoSupport.java
index c960ef8912..a2339c2b2a 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/FdoSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/FdoSupport.java
@@ -222,12 +222,12 @@ public class FdoSupport {
         : Root.asDerivedRoot(execRoot, execRoot.getRelative("blaze-fdo"));
     this.fdoRootExecPath = fdoProfile == null
         ? null
-        : fdoRoot.getExecPath().getRelative(new PathFragment("_fdo").getChild(
-            FileSystemUtils.removeExtension(fdoProfile.getBaseName())));
+        : fdoRoot.getExecPath().getRelative(FileSystemUtils.removeExtension(
+            new PathFragment("_fdo").getChild(fdoProfile.getBaseName())));
     this.fdoPath = fdoProfile == null
         ? null
-        : new PathFragment("_fdo").getChild(
-            FileSystemUtils.removeExtension(fdoProfile.getBaseName()));
+        : FileSystemUtils.removeExtension(new PathFragment("_fdo").getChild(
+            fdoProfile.getBaseName()));
     this.lipoMode = lipoMode;
     this.useAutoFdo = fdoProfile != null && isAutoFdo(fdoProfile.getBaseName());
     this.useLLVMFdo = fdoProfile != null && isLLVMFdo(fdoProfile.getBaseName());
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java b/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java
index 796d8286e2..6ce67aeac2 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/FileSystemUtils.java
@@ -157,7 +157,10 @@ public class FileSystemUtils {
    * filename string. If the basename contains no '.', the filename is returned
    * unchanged.
    *
-   * e.g. "foo/bar.x" -> "foo/bar"
+   * <p>e.g. "foo/bar.x" -> "foo/bar"
+   *
+   * <p>Note that if the filename is composed entirely of ".", this method will return the string
+   * with one fewer ".", which may have surprising effects.
    */
   @ThreadSafe
   public static String removeExtension(String filename) {
@@ -176,6 +179,9 @@ public class FileSystemUtils {
    * unchanged.
    *
    * <p>e.g. "foo/bar.x" -> "foo/bar"
+   *
+   * <p>Note that if the base filename is composed entirely of ".", this method will return the
+   * filename with one fewer "." in the base filename, which may have surprising effects.
    */
   @ThreadSafe
   public static PathFragment removeExtension(PathFragment path) {
@@ -188,6 +194,9 @@ public class FileSystemUtils {
    * unchanged.
    *
    * <p>e.g. "foo/bar.x" -> "foo/bar"
+   *
+   * <p>Note that if the base filename is composed entirely of ".", this method will return the
+   * filename with one fewer "." in the base filename, which may have surprising effects.
    */
   @ThreadSafe
   public static Path removeExtension(Path path) {