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: #5723 Closes #5982. PiperOrigin-RevId: 210646978
bazelbuild · Sep 7, 2018 · a5ac7e5 · a5ac7e5
1 parent e66b90f
commit a5ac7e5
Show file tree

Hide file tree

Showing 4 changed files with 68 additions and 45 deletions.
diff --git a/src/java_tools/buildjar/BUILD b/src/java_tools/buildjar/BUILD
@@ -77,7 +77,7 @@ java_toolchain(
     # class path after -bootclasspath. For convenience, we currently have a
     # single jar that contains the contents of both the bootclasspath and
     # extdirs.
-    bootclasspath = ["//tools/jdk:platformclasspath.jar"],
+    bootclasspath = ["//tools/jdk:platformclasspath8.jar"],
     extclasspath = [],
     genclass = ["bootstrap_genclass_deploy.jar"],
     ijar = ["//third_party/ijar"],

diff --git a/tools/android/BUILD.tools b/tools/android/BUILD.tools
@@ -100,7 +100,7 @@ gen_java_lang_extras_jar_cmd = """
     $(location %s) \
         --exclude_build_data \
         --dont_change_compression \
-        --sources  $(location @bazel_tools//tools/jdk:platformclasspath) \
+        --sources  $(location @bazel_tools//tools/jdk:platformclasspath8) \
         --include_prefixes "java/lang/invoke/" \
         --include_prefixes "java/lang/annotation/" \
         --output $@
@@ -111,7 +111,7 @@ gen_java_lang_extras_jar_cmd = """
 genrule(
     name = "gen_java_lang_extras_jar",
     srcs = [
-        "@bazel_tools//tools/jdk:platformclasspath"
+        "@bazel_tools//tools/jdk:platformclasspath8"
     ],
     tools = select({
         "//src/conditions:windows": [":singlejar_javabin"],
@@ -176,7 +176,7 @@ genrule(
     $(location :desugar_java8) \
         --input $< \
         --output $@ \
-        --classpath_entry "$(location @bazel_tools//tools/jdk:platformclasspath)" \
+        --classpath_entry "$(location @bazel_tools//tools/jdk:platformclasspath8)" \
         --core_library --allow_empty_bootclasspath \
         --nobest_effort_tolerate_missing_deps \
         --noemit_dependency_metadata_as_needed \
@@ -213,7 +213,7 @@ genrule(
         --dont_rewrite_core_library_invocation "java/util/Iterator#remove" """,
     tools = [
         ":desugar_java8",
-        "@bazel_tools//tools/jdk:platformclasspath",
+        "@bazel_tools//tools/jdk:platformclasspath8",
     ],
     visibility = ["//visibility:private"],
 )

diff --git a/tools/jdk/BUILD b/tools/jdk/BUILD
@@ -169,57 +169,59 @@ alias(
     actual = "@embedded_jdk//:jdk",
 )
 
-genrule(
-    name = "platformclasspath",
-    srcs = ["DumpPlatformClassPath.java"],
-    outs = ["platformclasspath.jar"],
-    cmd = """
+RELEASES = (8, 9, 10)
+
+# Create jars containing compile-time bootclasspaths for each Java version
+# in RELEASES, using javac to read those APIs via the infrastructure added
+# for the --release flag (see http://openjdk.java.net/jeps/247).
+[
+    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(
+# Default to the Java 8 language level.
+# TODO(cushon): consider if/when we should increment this?
+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
@@ -46,22 +46,24 @@
 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<>();
 
-    // JDK 8 bootclasspath handling
+    // Legacy JDK 8 bootclasspath handling.
+    // TODO(cushon): make sure this has test coverage.
     Path javaHome = Paths.get(System.getProperty("java.home"));
     if (javaHome.endsWith("jre")) {
       javaHome = javaHome.getParent();
@@ -85,13 +87,32 @@ public static void main(String[] args) throws Exception {
       }
     }
 
-    if (entries.isEmpty()) {
-      // JDK > 8 bootclasspath handling
+    if (!entries.isEmpty()) {
+      // If we found a JDK 8 bootclasspath (rt.jar, etc.) then we're done.
+      //
+      // However JDK 8 only contains bootclasspath API information for the current release,
+      // so we're always going to get a JDK 8 API level regardless of what the user requested.
+      // Emit a warning if they wanted to target a different version.
+      if (release != 8) {
+        System.err.printf(
+            "warning: ignoring release %s on --host_javabase=%s\n",
+            release, System.getProperty("java.version"));
+      }
+    } else {
+      // JDK > 8 --host_javabase bootclasspath handling.
+      // The default --host_javabase is currently JDK 10.
 
-      // Set up a compilation with --release 8 to initialize a filemanager
+      // Set up a compilation with --release 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 :