Deprecate IFrameLinker and XSLinker

They'll also emit a warning at compile-time, unless suppressed by setting
the iframe.linker.suppressDeprecationWarning configuration property to
true.

Bug: issue 8578
Change-Id: I7a119390240130f6846c11d14424d2eaa8e51061

dev/core/src/com/google/gwt/core/linker/IFrameLinker.java

diff --git a/dev/core/src/com/google/gwt/core/linker/IFrameLinker.java b/dev/core/src/com/google/gwt/core/linker/IFrameLinker.java
index fae5c92..be81b4d 100644
--- a/dev/core/src/com/google/gwt/core/linker/IFrameLinker.java
+++ b/dev/core/src/com/google/gwt/core/linker/IFrameLinker.java
@@ -18,6 +18,8 @@
 import com.google.gwt.core.ext.LinkerContext;
 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.UnableToCompleteException;
+import com.google.gwt.core.ext.linker.ArtifactSet;
+import com.google.gwt.core.ext.linker.ConfigurationProperty;
 import com.google.gwt.core.ext.linker.LinkerOrder;
 import com.google.gwt.core.ext.linker.LinkerOrder.Order;
 import com.google.gwt.core.ext.linker.Shardable;
@@ -28,19 +30,46 @@
 /**
  * Implements the canonical GWT bootstrap sequence that loads the GWT module in
  * a separate iframe.
+ *
+ * @deprecated use {@link CrossSiteIframeLinker} instead.
  */
 @LinkerOrder(Order.PRIMARY)
 @Shardable
+@Deprecated
 public class IFrameLinker extends SelectionScriptLinker {
+  private static final String SUPPRESS_DEPRECATION_WARNING_PROPERTY = "iframe.linker.suppressDeprecationWarning";
+
   /**
    * This string is inserted between script chunks. It is made default access
    * for testing.
    */
   static final String SCRIPT_CHUNK_SEPARATOR = "--></script>\n<script><!--\n";
 
+  // Also used by the XSLinker.
+  static void maybeEmitDeprecationWarning(String linkerName, TreeLogger logger, LinkerContext context) {
+    boolean suppressDeprecationWarning = false;
+    for (ConfigurationProperty prop : context.getConfigurationProperties()) {
+      if (SUPPRESS_DEPRECATION_WARNING_PROPERTY.equals(prop.getName())) {
+        suppressDeprecationWarning = Boolean.parseBoolean(prop.getValues().get(0));
+        break;
+      }
+    }
+    if (!suppressDeprecationWarning) {
+      logger.log(TreeLogger.WARN,
+          linkerName + " linker is deprecated; consider switching to the xsiframe linker");
+    }
+  }
+
   @Override
   public String getDescription() {
-    return "Standard";
+    return "IFrame";
+  }
+
+  @Override
+  public ArtifactSet link(TreeLogger logger, LinkerContext context, ArtifactSet artifacts,
+      boolean onePermutation) throws UnableToCompleteException {
+    maybeEmitDeprecationWarning(getDescription(), logger, context);
+    return super.link(logger, context, artifacts, onePermutation);
   }
 
   @Override
@@ -179,5 +208,4 @@
     out.newline();
     return out.toString();
   }
-
 }

dev/core/src/com/google/gwt/core/linker/XSLinker.java

diff --git a/dev/core/src/com/google/gwt/core/linker/XSLinker.java b/dev/core/src/com/google/gwt/core/linker/XSLinker.java
index d379794..be23647 100644
--- a/dev/core/src/com/google/gwt/core/linker/XSLinker.java
+++ b/dev/core/src/com/google/gwt/core/linker/XSLinker.java
@@ -17,6 +17,7 @@
 
 import com.google.gwt.core.ext.LinkerContext;
 import com.google.gwt.core.ext.TreeLogger;
+import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.core.ext.linker.ArtifactSet;
 import com.google.gwt.core.ext.linker.LinkerOrder;
 import com.google.gwt.core.ext.linker.LinkerOrder.Order;
@@ -28,9 +29,12 @@
 
 /**
  * Generates a cross-site compatible bootstrap sequence.
+ *
+ * @deprecated use {@link CrossSiteIframeLinker} instead.
  */
 @LinkerOrder(Order.PRIMARY)
 @Shardable
+@Deprecated
 public class XSLinker extends SelectionScriptLinker {
   @Override
   public String getDescription() {
@@ -38,6 +42,13 @@
   }
 
   @Override
+  public ArtifactSet link(TreeLogger logger, LinkerContext context, ArtifactSet artifacts,
+      boolean onePermutation) throws UnableToCompleteException {
+    IFrameLinker.maybeEmitDeprecationWarning(getDescription(), logger, context);
+    return super.link(logger, context, artifacts, onePermutation);
+  }
+
+  @Override
   protected String getCompilationExtension(TreeLogger logger,
       LinkerContext context) {
     return ".cache.js";

user/src/com/google/gwt/core/Core.gwt.xml

diff --git a/user/src/com/google/gwt/core/Core.gwt.xml b/user/src/com/google/gwt/core/Core.gwt.xml
index 8196234..55d11bf 100644
--- a/user/src/com/google/gwt/core/Core.gwt.xml
+++ b/user/src/com/google/gwt/core/Core.gwt.xml
@@ -43,6 +43,10 @@
   <inherits name="com.google.gwt.core.XSLinker" />
   <inherits name="com.google.gwt.core.CrossSiteIframeLinker" />
 
+  <!-- std and xs linkers are deprecated and will emit a warning, which can be turned off -->
+  <define-configuration-property name="iframe.linker.suppressDeprecationWarning" is-multi-valued="false" />
+  <set-configuration-property name="iframe.linker.suppressDeprecationWarning" value="false" />
+
   <!-- When true, compiles in support for GWT.unloadModule(), otherwise it is a no-op. -->
   <define-property name="gwt.unloadEnabled" values="false, true"/>
   <set-property name="gwt.unloadEnabled" value="false"/>