Normalize keys option

.bazelversion

@@ -0,0 +1 @@
+6.0.0

.gitignore

@@ -4,3 +4,4 @@ bazel-bin
 bazel-out
 bazel-testlogs
 bazel-execlog-parser
+bazel-exec-log-differ

src/main/java/com/airbnb/execlog_parser/ExecLogParser.kt

@@ -6,6 +6,7 @@ import java.io.File
 import java.io.FileInputStream
 import java.io.IOException
 import java.io.InputStream
+import java.nio.file.Paths
 import kotlin.jvm.Throws
 
 object ExecLogParser {
@@ -20,8 +21,12 @@ object ExecLogParser {
     return SpawnExec.parseDelimitedFrom(inputStream)
   }
 
+  fun normalizePath(path: String): String {
+    return path.replace(Regex("^bazel-out/.*?/"), "<bazel-out>/")
+  }
+
   @Throws(IOException::class)
-  fun getFileDigests(logPath: String): LinkedHashMap<String, Digest> {
+  fun getFileDigests(logPath: String, normalizePaths: Boolean): LinkedHashMap<String, Digest> {
     inputStream = FileInputStream(logPath)
     val fileHashMap = LinkedHashMap<String, Digest>()
     var spawnExec = getNext()
@@ -30,34 +35,50 @@ object ExecLogParser {
         val digest = fileProto.digest
         val hash = digest.hash
         val path = fileProto.path
-        if (fileHashMap.get(path) != null && fileHashMap.get(path)!!.hash != hash) {
+        var key = path
+        if (normalizePaths) {
+          key = normalizePath(path)
+        }
+        if (fileHashMap.get(key) != null && fileHashMap.get(key)!!.hash != hash) {
           throw Exception(
             "File hash changed during bazel build.  Something is seriously wrong!\n" +
-              "$path has at least two different hashes: ${fileHashMap[path]} $hash\n"
+              "$key has at least two different hashes: ${fileHashMap.get(key)!!.hash} $hash\n"
           )
         }
-        fileHashMap[path] = digest
+        fileHashMap[key] = digest
       }
       spawnExec = getNext()
     }
     return fileHashMap
   }
 
   @JvmStatic fun main(arg: Array<String>) {
-    if (arg.size < 2) {
+    val argsList = arg.toMutableList()
+
+    var normalizePaths = false
+    if (argsList.contains("--normalizePaths")) {
+        normalizePaths = true
+        argsList.remove("--normalizePaths")
+    }
+
+    if (argsList.size < 2) {
       println("This program takes in 2-3 arguments:")
       println("logPath1 logPath2 [allowlist of filepaths]")
       throw Exception("Invalid arguments")
     }
-    val logPath1 = arg.get(0)
-    val logPath2 = arg.get(1)
-    val allowListPath = arg.getOrNull(2)
+
+    // Resolve relative paths to the current working directory. This is a noop if the path is already
+    // absolute.
+    val logPath1 = Paths.get(argsList.get(0)).toAbsolutePath().toString()
+    val logPath2 = Paths.get(argsList.get(1)).toAbsolutePath().toString()
+    val allowListPath = argsList.getOrNull(2)?.let { Paths.get(it).toAbsolutePath().toString() }
     var allowList = setOf<String>()
     if (allowListPath != null) {
       allowList = File(allowListPath).readLines().map { it.trim() }.toSet()
     }
-    val fileHashMap1 = getFileDigests(logPath1)
-    val fileHashMap2 = getFileDigests(logPath2)
+    val fileHashMap1 = getFileDigests(logPath1, normalizePaths)
+    val fileHashMap2 = getFileDigests(logPath2, normalizePaths)
+
     if (fileHashMap1.keys != fileHashMap2.keys) {
       throw Exception(
         "Execution logs have different sets of inputs and outputs!\n" +