From 1f0a1283d029962a238c21f0c1f2607d47e1f20e Mon Sep 17 00:00:00 2001
From: Liam Miller-Cushon <cushon@google.com>
Date: Fri, 8 Mar 2024 12:28:13 -0800
Subject: [PATCH] Fix parsing of `open module ... {}` module declarations

Prompted by https://github.com/google/error-prone/pull/4311

PiperOrigin-RevId: 614012108
---
 java/com/google/turbine/parse/Parser.java        |  6 +++++-
 .../turbine/lower/ModuleIntegrationTest.java     |  3 ++-
 .../lower/moduletestdata/module-info-open.test   |  5 +++++
 .../com/google/turbine/parse/ParseErrorTest.java | 16 ++++++++++++++++
 4 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 javatests/com/google/turbine/lower/moduletestdata/module-info-open.test

diff --git a/java/com/google/turbine/parse/Parser.java b/java/com/google/turbine/parse/Parser.java
index 0f2a46ff..3336ae8d 100644
--- a/java/com/google/turbine/parse/Parser.java
+++ b/java/com/google/turbine/parse/Parser.java
@@ -210,7 +210,11 @@ public CompUnit compilationUnit() {
                 && (ident.value().equals("module") || ident.value().equals("open"))) {
               boolean open = false;
               if (ident.value().equals("open")) {
-                ident = eatIdent();
+                next();
+                if (token != IDENT) {
+                  throw error(token);
+                }
+                ident = ident();
                 open = true;
               }
               if (!ident.value().equals("module")) {
diff --git a/javatests/com/google/turbine/lower/ModuleIntegrationTest.java b/javatests/com/google/turbine/lower/ModuleIntegrationTest.java
index 0157fea3..7cc7952e 100644
--- a/javatests/com/google/turbine/lower/ModuleIntegrationTest.java
+++ b/javatests/com/google/turbine/lower/ModuleIntegrationTest.java
@@ -47,6 +47,7 @@ public static Iterable<Object[]> parameters() {
       "module-info.test", //
       "classpath.test",
       "multimodule.test",
+      "module-info-open.test",
     };
     return ImmutableList.copyOf(testCases).stream().map(x -> new Object[] {x}).collect(toList());
   }
@@ -61,7 +62,7 @@ public ModuleIntegrationTest(String test) {
 
   @Test
   public void test() throws Exception {
-    if (Double.parseDouble(JAVA_CLASS_VERSION.value()) < 53) {
+    if (Runtime.version().feature() < 9) {
       // only run on JDK 9 and later
       return;
     }
diff --git a/javatests/com/google/turbine/lower/moduletestdata/module-info-open.test b/javatests/com/google/turbine/lower/moduletestdata/module-info-open.test
new file mode 100644
index 00000000..70bd1a9c
--- /dev/null
+++ b/javatests/com/google/turbine/lower/moduletestdata/module-info-open.test
@@ -0,0 +1,5 @@
+=== module-info.java ===
+open module com.google.foop.annotation {
+  requires java.base;
+  requires java.compiler;
+}
diff --git a/javatests/com/google/turbine/parse/ParseErrorTest.java b/javatests/com/google/turbine/parse/ParseErrorTest.java
index f23b9575..9abb562d 100644
--- a/javatests/com/google/turbine/parse/ParseErrorTest.java
+++ b/javatests/com/google/turbine/parse/ParseErrorTest.java
@@ -475,6 +475,22 @@ public void typeAnnotationBeforeParam() {
                 "                ^"));
   }
 
+  @Test
+  public void moduleInfoOpen() {
+    String input =
+        lines(
+            "open {", //
+            "}");
+    TurbineError e = assertThrows(TurbineError.class, () -> Parser.parse(input));
+    assertThat(e)
+        .hasMessageThat()
+        .isEqualTo(
+            lines(
+                "<>:1: error: unexpected token: {", //
+                "open {",
+                "     ^"));
+  }
+
   private static String lines(String... lines) {
     return Joiner.on(System.lineSeparator()).join(lines);
   }