diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupFunction.java
index fe44617..9bc6bf2 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupFunction.java
@@ -52,19 +52,24 @@
     /** If {@code lookupSuccessful()}, returns the {@link RootedPath} to the file. */
     public abstract RootedPath rootedPath();
 
+    /** If {@code lookupSuccessful()}, returns the file's size, in bytes. */
+    public abstract long fileSize();
+
     static FileLookupResult noFile() {
       return UnsuccessfulFileResult.INSTANCE;
     }
 
-    static FileLookupResult file(RootedPath rootedPath) {
-      return new SuccessfulFileResult(rootedPath);
+    static FileLookupResult file(RootedPath rootedPath, long fileSize) {
+      return new SuccessfulFileResult(rootedPath, fileSize);
     }
 
     private static class SuccessfulFileResult extends FileLookupResult {
       private final RootedPath rootedPath;
+      private final long fileSize;
 
-      private SuccessfulFileResult(RootedPath rootedPath) {
+      private SuccessfulFileResult(RootedPath rootedPath, long fileSize) {
         this.rootedPath = rootedPath;
+        this.fileSize = fileSize;
       }
 
       @Override
@@ -76,6 +81,11 @@
       public RootedPath rootedPath() {
         return rootedPath;
       }
+
+      @Override
+      public long fileSize() {
+        return fileSize;
+      }
     }
 
     private static class UnsuccessfulFileResult extends FileLookupResult {
@@ -92,6 +102,11 @@
       public RootedPath rootedPath() {
         throw new IllegalStateException("unsuccessful lookup");
       }
+
+      @Override
+      public long fileSize() {
+        throw new IllegalStateException("unsuccessful lookup");
+      }
     }
   }
 
@@ -121,12 +136,13 @@
     }
     BuildFileAST ast = null;
     Path path = lookupResult.rootedPath().asPath();
+    long fileSize = lookupResult.fileSize();
     // Skylark files end with bzl.
     boolean parseAsSkylark = astFilePathFragment.getPathString().endsWith(".bzl");
     try {
       if (parseAsSkylark) {
         try (Mutability mutability = Mutability.create("validate")) {
-            ast = BuildFileAST.parseSkylarkFile(path, env.getListener(),
+            ast = BuildFileAST.parseSkylarkFile(path, fileSize, env.getListener(),
                 packageManager, new ValidationEnvironment(
                     ruleClassProvider.createSkylarkRuleClassEnvironment(
                         mutability,
@@ -137,7 +153,7 @@
                     .setupDynamic(Runtime.PKG_NAME, Runtime.NONE)));
         }
       } else {
-        ast = BuildFileAST.parseBuildFile(path, env.getListener(), packageManager, false);
+        ast = BuildFileAST.parseBuildFile(path, fileSize, env.getListener(), packageManager, false);
       }
     } catch (IOException e) {
         throw new ASTLookupFunctionException(new ErrorReadingSkylarkExtensionException(
@@ -177,7 +193,7 @@
         return null;
       }
       if (fileValue.isFile()) {
-        return FileLookupResult.file(rootedPath);
+        return FileLookupResult.file(rootedPath, fileValue.getSize());
       }
     }
     return FileLookupResult.noFile();
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java
index 12eea02..cf0bf4e 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java
@@ -446,7 +446,7 @@
         // Skylark dependencies.
         reporter.handle(Event.progress("Loading package: " + packageName));
       }
-      inputSource = ParserInputSource.create(buildFilePath);
+      inputSource = ParserInputSource.create(buildFilePath, buildFileValue.getSize());
     } catch (IOException e) {
       env.getListener().handle(Event.error(Location.fromFile(buildFilePath), e.getMessage()));
       // Note that we did this work, so we should conservatively report this error as transient.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java
index ce45ca2..14a40da 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java
@@ -78,7 +78,7 @@
       }
 
       try {
-        parser.parse(ParserInputSource.create(repoWorkspace));
+        parser.parse(ParserInputSource.create(repoWorkspace, workspaceFileValue.getSize()));
       } catch (IOException e) {
         throw new WorkspaceFileFunctionException(e, Transience.TRANSIENT);
       }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java b/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java
index 8dac01e..cdd75d3 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java
@@ -218,7 +218,14 @@
   public static BuildFileAST parseBuildFile(Path buildFile, EventHandler eventHandler,
                                             CachingPackageLocator locator, boolean parsePython)
       throws IOException {
-    ParserInputSource inputSource = ParserInputSource.create(buildFile);
+    return parseBuildFile(buildFile, buildFile.getFileSize(), eventHandler, locator, parsePython);
+  }
+
+  public static BuildFileAST parseBuildFile(Path buildFile, long fileSize,
+                                            EventHandler eventHandler,
+                                            CachingPackageLocator locator, boolean parsePython)
+      throws IOException {
+    ParserInputSource inputSource = ParserInputSource.create(buildFile, fileSize);
     return parseBuildFile(inputSource, eventHandler, locator, parsePython);
   }
 
@@ -261,7 +268,14 @@
   public static BuildFileAST parseSkylarkFile(Path file, EventHandler eventHandler,
       CachingPackageLocator locator, ValidationEnvironment validationEnvironment)
           throws IOException {
-    ParserInputSource input = ParserInputSource.create(file);
+    return parseSkylarkFile(file, file.getFileSize(), eventHandler, locator,
+        validationEnvironment);
+  }
+
+  public static BuildFileAST parseSkylarkFile(Path file, long fileSize, EventHandler eventHandler,
+      CachingPackageLocator locator, ValidationEnvironment validationEnvironment)
+          throws IOException {
+    ParserInputSource input = ParserInputSource.create(file, fileSize);
     Lexer lexer = new Lexer(input, eventHandler, false);
     Parser.ParseResult result =
         Parser.parseFileForSkylark(lexer, eventHandler, locator, validationEnvironment);
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ParserInputSource.java b/src/main/java/com/google/devtools/build/lib/syntax/ParserInputSource.java
index 82b2a44..0877baa 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ParserInputSource.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ParserInputSource.java
@@ -45,12 +45,19 @@
    * all we care about here.
    */
   public static ParserInputSource create(Path path) throws IOException {
+    return create(path, path.getFileSize());
+  }
+
+  public static ParserInputSource create(Path path, long fileSize) throws IOException {
+    if (fileSize > Integer.MAX_VALUE) {
+      throw new IOException("Cannot parse file with size larger than 2GB");
+    }
     char[] content = FileSystemUtils.readContentAsLatin1(path);
-    if (path.getFileSize() > content.length) {
+    if (fileSize > content.length) {
       // This assertion is to help diagnose problems arising from the
       // filesystem;  see bugs and #859334 and #920195.
       throw new IOException("Unexpected short read from file '" + path
-          + "' (expected " + path.getFileSize() + ", got " + content.length + " bytes)");
+          + "' (expected " + fileSize + ", got " + content.length + " bytes)");
     }
     return create(content, path.asFragment());
   }
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java b/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java
index 7068278..02e1f8b 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java
@@ -664,7 +664,11 @@
    */
   protected Rule scratchRule(String packageName, String ruleName, String... lines)
       throws Exception {
-    scratch.file(packageName + "/BUILD", lines);
+    String buildFilePathString = packageName + "/BUILD";
+    scratch.file(buildFilePathString, lines);
+    skyframeExecutor.invalidateFilesUnderPathForTesting(
+        new ModifiedFileSet.Builder().modify(new PathFragment(buildFilePathString)).build(),
+        rootDirectory);
     return (Rule) getTarget("//" + packageName + ":" + ruleName);
   }