Add flag to control native maven jar rule deprecation.

Closes #6768.
Relevant to #6799.

PiperOrigin-RevId: 223375698

site/docs/skylark/backward-compatibility.md

@@ -63,6 +63,7 @@ External repositories
 
 *   [Remove native git repository](#remove-native-git-repository)
 *   [Remove native http archive](#remove-native-http-archive)
+*   [Remove native maven jar](#remove-native-maven-jar)
 
 Java
 
@@ -394,6 +395,61 @@ parameter, not `url`).
 *   Flag: `--incompatible_remove_native_http_archive`
 *   Default: `true`
 
+### Remove native maven jar
+
+When set, the native `maven_jar` rule is disabled. The Starlark version
+
+```python
+load("@bazel_tools//tools/build_defs/repo:java.bzl", "java_import_external")
+```
+
+or the convenience wrapper
+
+```python
+load("@bazel_tools//tools/build_defs/repo:jvm.bzl", "jvm_maven_import_external")
+```
+
+should be used instead. These rules are more reliable and offer additional
+functionality over the native `maven_jar` rule. In addition to downloading
+the jars, they allow defining the jar's dependencies. They also enable
+downloading src-jars.
+
+Given a `WORKSPACE` file that looks like the following:
+
+```python
+maven_jar(
+    name = "truth",
+    artifact = "com.google.truth:truth:0.30",
+    sha1 = "9d591b5a66eda81f0b88cf1c748ab8853d99b18b",
+)
+```
+
+It will need to look like this after updating:
+```python
+load("@bazel_tools//tools/build_defs/repo:jvm.bzl", "jvm_maven_import_external")
+jvm_maven_import_external(
+    name = "truth",
+    artifact = "com.google.truth:truth:0.30",
+    artifact_sha256 = "59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a",
+    server_urls = ["http://central.maven.org/maven2"],
+    licenses = ["notice"],  # Apache 2.0
+)
+```
+
+Notably
+*   the `licenses` attribute is mandatory
+*   sha1 is no longer supported, only sha256 is
+*   the `server_urls` attribute is mandatory. If your `maven_jar` rule
+    did not specify a url then you should use the default server
+    ("http://central.maven.org/maven2"). If your rule did specify a url then
+    keep using that one.
+
+Documentation for the rule is
+[here](https://source.bazel.build/bazel/+/master:tools/build_defs/repo/java.bzl;l=15).
+
+*   Flag: `--incompatible_remove_native_maven_jar`
+*   Default: `false`
+
 ### New-style JavaInfo constructor
 
 When set, `java_common.create_provider` and certain arguments to `JavaInfo` are deprecated. The

src/main/java/com/google/devtools/build/lib/bazel/repository/MavenJarFunction.java

@@ -24,7 +24,9 @@
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.rules.repository.RepositoryDirectoryValue;
 import com.google.devtools.build.lib.rules.repository.WorkspaceAttributeMapper;
+import com.google.devtools.build.lib.skyframe.PrecomputedValue;
 import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.lib.syntax.SkylarkSemantics;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.util.Fingerprint;
 import com.google.devtools.build.lib.vfs.Path;
@@ -96,6 +98,24 @@ private static MavenServerValue getServer(Rule rule, Environment env)
   public RepositoryDirectoryValue.Builder fetch(Rule rule, Path outputDirectory,
       BlazeDirectories directories, Environment env, Map<String, String> markerData)
       throws RepositoryFunctionException, InterruptedException {
+
+    // Deprecation in favor of the Starlark rule
+    SkylarkSemantics skylarkSemantics = PrecomputedValue.SKYLARK_SEMANTICS.get(env);
+    if (skylarkSemantics == null) {
+      return null;
+    }
+    if (skylarkSemantics.incompatibleRemoveNativeMavenJar()) {
+      throw new RepositoryFunctionException(
+          new EvalException(
+              null,
+              "The native maven_jar rule is deprecated."
+                  + " See https://docs.bazel.build/versions/master/skylark/"
+                  + "backward-compatibility.html#remove-native-maven-jar for migration information."
+                  + "\nUse --incompatible_remove_native_maven_jar=false to temporarily continue"
+                  + " using the native rule."),
+          Transience.PERSISTENT);
+    }
+
     MavenServerValue serverValue = getServer(rule, env);
     if (env.valuesMissing()) {
       return null;

src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsOptions.java

@@ -476,6 +476,20 @@ public class SkylarkSemanticsOptions extends OptionsBase implements Serializable
               + "will be available")
   public boolean incompatibleRemoveNativeHttpArchive;
 
+  @Option(
+      name = "incompatible_remove_native_maven_jar",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.SKYLARK_SEMANTICS,
+      effectTags = {OptionEffectTag.BUILD_FILE_SEMANTICS},
+      metadataTags = {
+        OptionMetadataTag.INCOMPATIBLE_CHANGE,
+        OptionMetadataTag.TRIGGERED_BY_ALL_INCOMPATIBLE_CHANGES
+      },
+      help =
+          "If set to true, the native maven_jar rule is disabled; only the Starlark version "
+              + "will be available")
+  public boolean incompatibleRemoveNativeMavenJar;
+
   @Option(
       name = "incompatible_static_name_resolution",
       defaultValue = "true",
@@ -566,6 +580,7 @@ public SkylarkSemantics toSkylarkSemantics() {
         .incompatibleRangeType(incompatibleRangeType)
         .incompatibleRemoveNativeGitRepository(incompatibleRemoveNativeGitRepository)
         .incompatibleRemoveNativeHttpArchive(incompatibleRemoveNativeHttpArchive)
+        .incompatibleRemoveNativeMavenJar(incompatibleRemoveNativeMavenJar)
         .incompatibleStaticNameResolution(incompatibleStaticNameResolution)
         .incompatibleStricArgumentOrdering(incompatibleStricArgumentOrdering)
         .incompatibleStringIsNotIterable(incompatibleStringIsNotIterable)

src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java

@@ -176,6 +176,8 @@ public boolean flagValue(FlagIdentifier flagIdentifier) {
 
   public abstract boolean incompatibleRemoveNativeHttpArchive();
 
+  public abstract boolean incompatibleRemoveNativeMavenJar();
+
   public abstract boolean incompatibleStaticNameResolution();
 
   public abstract boolean incompatibleStricArgumentOrdering();
@@ -231,6 +233,7 @@ public static Builder builderWithDefaults() {
           .incompatibleRangeType(true)
           .incompatibleRemoveNativeGitRepository(true)
           .incompatibleRemoveNativeHttpArchive(true)
+          .incompatibleRemoveNativeMavenJar(false)
           .incompatibleStaticNameResolution(true)
           .incompatibleStricArgumentOrdering(false)
           .incompatibleStringIsNotIterable(false)
@@ -306,6 +309,8 @@ public abstract static class Builder {
 
     public abstract Builder incompatibleRemoveNativeHttpArchive(boolean value);
 
+    public abstract Builder incompatibleRemoveNativeMavenJar(boolean value);
+
     public abstract Builder incompatibleStaticNameResolution(boolean value);
 
     public abstract Builder incompatibleStricArgumentOrdering(boolean value);

src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java

@@ -153,6 +153,7 @@ private static SkylarkSemanticsOptions buildRandomOptions(Random rand) throws Ex
         "--incompatible_range_type=" + rand.nextBoolean(),
         "--incompatible_remove_native_git_repository=" + rand.nextBoolean(),
         "--incompatible_remove_native_http_archive=" + rand.nextBoolean(),
+        "--incompatible_remove_native_maven_jar=" + rand.nextBoolean(),
         "--incompatible_static_name_resolution=" + rand.nextBoolean(),
         "--incompatible_strict_argument_ordering=" + rand.nextBoolean(),
         "--incompatible_string_is_not_iterable=" + rand.nextBoolean(),
@@ -199,6 +200,7 @@ private static SkylarkSemantics buildRandomSemantics(Random rand) {
         .incompatibleRangeType(rand.nextBoolean())
         .incompatibleRemoveNativeGitRepository(rand.nextBoolean())
         .incompatibleRemoveNativeHttpArchive(rand.nextBoolean())
+        .incompatibleRemoveNativeMavenJar(rand.nextBoolean())
         .incompatibleStaticNameResolution(rand.nextBoolean())
         .incompatibleStricArgumentOrdering(rand.nextBoolean())
         .incompatibleStringIsNotIterable(rand.nextBoolean())