Summary

Add default-on lint category "incubating" and trigger incubating module warning according to the category.

Problem

Incubating module warning is not suppressible and -Werror turns incubator module warning to an error.

Solution

Add default-on lint category "incubating" and disable incubating module warning at compile time when the category is disabled.

Specification

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Lint.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Lint.java
index e9d64a6ad72..de37229f68f 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Lint.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Lint.java
@@ -130,6 +130,7 @@ protected Lint(Context context) {
                 values.add(LintCategory.PREVIEW);
             }
             values.add(LintCategory.SYNCHRONIZATION);
+            values.add(LintCategory.INCUBATING);
         }

         // Look for specific overrides
@@ -215,6 +216,11 @@ public enum LintCategory {
          */
         FINALLY("finally"),
+
+        /**
+         * Warn about use of incubating modules.
+         */
+        INCUBATING("incubating"),

         /**
           * Warn about compiler possible lossy conversions.
           */
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/javac.properties b/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/javac.properties
index d9bd05ba62a..7893d328afa 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/javac.properties
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/javac.properties
@@ -213,6 +213,9 @@ javac.opt.Xlint.desc.fallthrough=\
 javac.opt.Xlint.desc.finally=\
     Warn about finally clauses that do not terminate normally.

+javac.opt.Xlint.desc.incubating=\
+    Warn about use of incubating modules.
+
 javac.opt.Xlint.desc.lossy-conversions=\
     Warn about possible lossy conversions in compound assignment.

diff --git a/src/jdk.compiler/share/classes/module-info.java b/src/jdk.compiler/share/classes/module-info.java
index c8716233c0f..9826b3f576b 100644
--- a/src/jdk.compiler/share/classes/module-info.java
+++ b/src/jdk.compiler/share/classes/module-info.java
@@ -162,6 +162,7 @@
  * <tr><th scope="row">{@code fallthrough}          <td>falling through from one case of a {@code switch} statement to
  *                                                      the next
  * <tr><th scope="row">{@code finally}              <td>{@code finally} clauses that do not terminate normally
+ * <tr><th scope="row">{@code incubating}           <td>use of incubating modules
  * <tr><th scope="row">{@code lossy-conversions}    <td>possible lossy conversions in compound assignment
  * <tr><th scope="row">{@code missing-explicit-ctor} <td>missing explicit constructors in public and protected classes
  *                                                      in exported packages
diff --git a/src/jdk.compiler/share/man/javac.1 b/src/jdk.compiler/share/man/javac.1
index 30b260ac648..b8a7fe60af5 100644
--- a/src/jdk.compiler/share/man/javac.1
+++ b/src/jdk.compiler/share/man/javac.1
@@ -725,6 +725,8 @@ a switch statement to the next.
 \f[V]finally\f[R]: Warns about \f[V]finally\f[R] clauses that do not
 terminate normally.
 .IP \[bu] 2
+\f[V]incubating\f[R]: Warns about the use of incubating modules.
+.IP \[bu] 2
 \f[V]lossy-conversions\f[R]: Warns about possible lossy conversions in
 compound assignment.
 .IP \[bu] 2