Replace path implementation.

Path and PathFragment have been replaced with String-based implementations. They are pretty similar, but each method is dissimilar enough that I did not feel sharing code was appropriate.

A summary of changes:

PATH
====

* Subsumes LocalPath (deleted, its tests repurposed)
* Use a simple string to back Path
* Path instances are no longer interned; Reference equality will no longer work
* Always normalized (same as before)
* Some operations will now be slower, like instance compares (which were previously just a reference check)
* Multiple identical paths will now consume more memory since they are not interned

PATH FRAGMENT
=============

* Use a simple string to back PathFragment
* No more segment arrays with interned strings
* Always normalized
* Remove isNormalized
* Replace some isNormalizied uses with containsUpLevelReferences() to check if path fragments try to escape their scope
* To check if user input is normalized, supply static methods on PathFragment to validate the string before constructing a PathFragment
* Because PathFragments are always normalized, we have to replace checks for literal "." from PathFragment#getPathString to PathFragment#getSafePathString. The latter returns "." for the empty string.
* The previous implementation supported efficient segment semantics (segment count, iterating over segments). This is now expensive since we do longer have a segment array.

ARTIFACT
========

* Remove Path instance. It is instead dynamically constructed on request. This is necessary to avoid this CL becoming a memory regression.

RELNOTES: None
PiperOrigin-RevId: 185062932

7 files changed, 1 insertions, 18 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionFunctionTest.java
index 7c864789ec..f8b6a9db3d 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionFunctionTest.java
@@ -39,7 +39,6 @@ import com.google.devtools.build.lib.analysis.actions.SpawnActionTemplate.Output
 import com.google.devtools.build.lib.events.NullEventHandler;
 import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
 import com.google.devtools.build.lib.testutil.FoundationTestCase;
-import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.Root;
 import com.google.devtools.build.skyframe.EvaluationResult;
@@ -205,9 +204,7 @@ public final class ActionTemplateExpansionFunctionTest extends FoundationTestCas
 
   private SpecialArtifact createTreeArtifact(String path) {
     PathFragment execPath = PathFragment.create("out").getRelative(path);
-    Path fullPath = rootDirectory.getRelative(execPath);
     return new SpecialArtifact(
-        fullPath,
         ArtifactRoot.asDerivedRoot(rootDirectory, rootDirectory.getRelative("out")),
         execPath,
         ArtifactOwner.NullArtifactOwner.INSTANCE,
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java
index 1699fc25fc..21b0a10274 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java
@@ -250,10 +250,8 @@ public class ArtifactFunctionTest extends ArtifactFunctionTestCase {
 
   private Artifact createDerivedArtifact(String path) {
     PathFragment execPath = PathFragment.create("out").getRelative(path);
-    Path fullPath = root.getRelative(execPath);
     Artifact output =
         new Artifact(
-            fullPath,
             ArtifactRoot.asDerivedRoot(root, root.getRelative("out")),
             execPath,
             ALL_OWNER);
@@ -264,9 +262,7 @@ public class ArtifactFunctionTest extends ArtifactFunctionTestCase {
   private Artifact createMiddlemanArtifact(String path) {
     ArtifactRoot middlemanRoot =
         ArtifactRoot.middlemanRoot(middlemanPath, middlemanPath.getRelative("out"));
-    Path fullPath = middlemanRoot.getRoot().getRelative(path);
-    return new Artifact(
-        fullPath, middlemanRoot, middlemanRoot.getExecPath().getRelative(path), ALL_OWNER);
+    return new Artifact(middlemanRoot, middlemanRoot.getExecPath().getRelative(path), ALL_OWNER);
   }
 
   private SpecialArtifact createDerivedTreeArtifactWithAction(String path) {
@@ -277,9 +273,7 @@ public class ArtifactFunctionTest extends ArtifactFunctionTestCase {
 
   private SpecialArtifact createDerivedTreeArtifactOnly(String path) {
     PathFragment execPath = PathFragment.create("out").getRelative(path);
-    Path fullPath = root.getRelative(execPath);
     return new SpecialArtifact(
-        fullPath,
         ArtifactRoot.asDerivedRoot(root, root.getRelative("out")),
         execPath,
         ALL_OWNER,
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
index f7a989a4ae..48ccd7e341 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
@@ -620,7 +620,6 @@ public class FilesystemValueCheckerTest {
     outputDir.createDirectory();
     ArtifactRoot derivedRoot = ArtifactRoot.asDerivedRoot(fs.getPath("/"), outputDir);
     return new SpecialArtifact(
-        outputPath,
         derivedRoot,
         derivedRoot.getExecPath().getRelative(derivedRoot.getRoot().relativize(outputPath)),
         ArtifactOwner.NullArtifactOwner.INSTANCE,
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java
index 872de47ad0..25b510e18e 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java
@@ -171,10 +171,8 @@ public final class RecursiveFilesystemTraversalFunctionTest extends FoundationTe
 
   private Artifact derivedArtifact(String path) {
     PathFragment execPath = PathFragment.create("out").getRelative(path);
-    Path fullPath = rootDirectory.getRelative(execPath);
     Artifact output =
         new Artifact(
-            fullPath,
             ArtifactRoot.asDerivedRoot(rootDirectory, rootDirectory.getRelative("out")),
             execPath);
     return output;
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java b/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
index 3b39d03441..e63d1ea06e 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
@@ -336,9 +336,7 @@ public abstract class TimestampBuilderTestCase extends FoundationTestCase {
   Artifact createDerivedArtifact(FileSystem fs, String name) {
     Path execRoot = fs.getPath(TestUtils.tmpDir());
     PathFragment execPath = PathFragment.create("out").getRelative(name);
-    Path path = execRoot.getRelative(execPath);
     return new Artifact(
-        path,
         ArtifactRoot.asDerivedRoot(execRoot, execRoot.getRelative("out")),
         execPath,
         ACTION_LOOKUP_KEY);
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java
index 30b6c4caf8..5d24b9ef28 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactBuildTest.java
@@ -1192,9 +1192,7 @@ public class TreeArtifactBuildTest extends TimestampBuilderTestCase {
     FileSystem fs = scratch.getFileSystem();
     Path execRoot = fs.getPath(TestUtils.tmpDir());
     PathFragment execPath = PathFragment.create("out").getRelative(name);
-    Path path = execRoot.getRelative(execPath);
     return new SpecialArtifact(
-        path,
         ArtifactRoot.asDerivedRoot(execRoot, execRoot.getRelative("out")),
         execPath,
         ACTION_LOOKUP_KEY,
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactMetadataTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactMetadataTest.java
index 96bc4bed65..9e3fd39ddd 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactMetadataTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TreeArtifactMetadataTest.java
@@ -204,7 +204,6 @@ public class TreeArtifactMetadataTest extends ArtifactFunctionTestCase {
     Path fullPath = root.getRelative(execPath);
     SpecialArtifact output =
         new SpecialArtifact(
-            fullPath,
             ArtifactRoot.asDerivedRoot(root, root.getRelative("out")),
             execPath,
             ALL_OWNER,