Stop using --release in versioned java_toolchains

Using --release to target versions that support modules and are not the latest supported version (e.g. --release 9 on JDK 10) doesn't work: https://bugs.openjdk.java.net/browse/JDK-8209865 Related: bazelbuild#5723
cushon · Aug 24, 2018 · e793519 · e793519
1 parent 2e677fb
commit e793519
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Showing 2 changed files with 48 additions and 37 deletions.
diff --git a/tools/jdk/BUILD b/tools/jdk/BUILD
@@ -181,57 +181,54 @@ alias(
     actual = "@embedded_jdk//:jdk",
 )
 
-genrule(
-    name = "platformclasspath",
-    srcs = ["DumpPlatformClassPath.java"],
-    outs = ["platformclasspath.jar"],
-    cmd = """
+RELEASES = (8, 9, 10)
+
+[
+    genrule(
+        name = "platformclasspath%d" % release,
+        srcs = ["DumpPlatformClassPath.java"],
+        outs = ["platformclasspath%d.jar" % release],
+        cmd = """
 set -eu
 TMPDIR=$$(mktemp -d -t tmp.XXXXXXXX)
 $(JAVABASE)/bin/javac -source 8 -target 8 \
     -cp $(JAVABASE)/lib/tools.jar \
     -d $$TMPDIR $<
 $(JAVA) -XX:+IgnoreUnrecognizedVMOptions \
     --add-exports=jdk.compiler/com.sun.tools.javac.platform=ALL-UNNAMED \
-    -cp $$TMPDIR DumpPlatformClassPath $@
+    -cp $$TMPDIR DumpPlatformClassPath %d $@
 rm -rf $$TMPDIR
-""",
-    toolchains = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
-    tools = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
-)
+""" % release,
+        toolchains = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
+        tools = ["@bazel_tools//tools/jdk:current_host_java_runtime"],
+    )
+    for release in RELEASES
+]
 
 default_java_toolchain(
     name = "toolchain_hostjdk8",
-    bootclasspath = [":platformclasspath"],
+    bootclasspath = [":platformclasspath8"],
     forcibly_disable_header_compilation = True,
     javabuilder = [":vanillajavabuilder"],
     jvm_opts = [],
     source_version = "8",
     target_version = "8",
 )
 
-default_java_toolchain(
+alias(
     name = "toolchain",
-    bootclasspath = [":platformclasspath"],
-    source_version = "8",
-    target_version = "8",
-)
-
-default_java_toolchain(
-    name = "toolchain_java9",
-    misc = DEFAULT_JAVACOPTS + [
-        "--release",
-        "9",
-    ],
+    actual = "toolchain_java8",
 )
 
-default_java_toolchain(
-    name = "toolchain_java10",
-    misc = DEFAULT_JAVACOPTS + [
-        "--release",
-        "10",
-    ],
-)
+[
+    default_java_toolchain(
+        name = "toolchain_java%d" % release,
+        bootclasspath = [":platformclasspath%d" % release],
+        source_version = "%s" % release,
+        target_version = "%s" % release,
+    )
+    for release in RELEASES
+]
 
 filegroup(
     name = "srcs",

diff --git a/tools/jdk/DumpPlatformClassPath.java b/tools/jdk/DumpPlatformClassPath.java
@@ -46,18 +46,19 @@
 import javax.tools.StandardLocation;
 
 /**
- * Output a jar file containing all classes on the platform classpath of the current JDK.
+ * Output a jar file containing all classes on the platform classpath of the given JDK release.
  *
- * <p>usage: DumpPlatformClassPath <output jar>
+ * <p>usage: DumpPlatformClassPath <release version> <output jar>
  */
 public class DumpPlatformClassPath {
 
   public static void main(String[] args) throws Exception {
-    if (args.length != 1) {
-      System.err.println("usage: DumpPlatformClassPath <output jar>");
+    if (args.length != 2) {
+      System.err.println("usage: DumpPlatformClassPath <release version> <output jar>");
       System.exit(1);
     }
-    Path output = Paths.get(args[0]);
+    int release = Integer.parseInt(args[0]);
+    Path output = Paths.get(args[1]);
 
     Map<String, byte[]> entries = new HashMap<>();
 
@@ -85,13 +86,26 @@ public static void main(String[] args) throws Exception {
       }
     }
 
-    if (entries.isEmpty()) {
+    if (!entries.isEmpty()) {
+      if (release != 8) {
+        System.err.printf(
+            "warning: ignoring release %s on --host_javabase=%s\n",
+            release, System.getProperty("java.version"));
+      }
+    } else {
       // JDK > 8 bootclasspath handling
 
       // Set up a compilation with --release 8 to initialize a filemanager
       Context context = new Context();
       JavacTool.create()
-          .getTask(null, null, null, Arrays.asList("--release", "8"), null, null, context);
+          .getTask(
+              /* out = */ null,
+              /* fileManager = */ null,
+              /* diagnosticListener = */ null,
+              /* options = */ Arrays.asList("--release", String.valueOf(release)),
+              /* classes = */ null,
+              /* compilationUnits = */ null,
+              context);
       JavaFileManager fileManager = context.get(JavaFileManager.class);
 
       for (JavaFileObject fileObject :