Declare global define aliases that J2clUtilGetDefineRewriterPass can read from

This will allow goog.defines declared in goog.modules to be consumable by J2CL's
System.getProperty infrastructure. Since these reads are out-of-scope of the
declaration, we need to provide some hook to link the two. To do this we define
a global variable to serve as a well-known alias to the define.

For the J2CL pass we can assume what the global variable is based on the define
name, so we just simply replace the getProperty references with the appropriate
global, if it exists.

PiperOrigin-RevId: 719370016

Author: kevinoconnor7

src/com/google/javascript/jscomp/J2clUtilGetDefineRewriterPass.java

@@ -64,8 +64,9 @@ private void rewriteUtilGetDefine(NodeTraversal t, Node callNode) {
   }
 
   private Node getDefineReplacement(Node firstExpr, Node secondExpr) {
-    if (defines.contains(firstExpr.getString())) {
-      Node define = NodeUtil.newQName(compiler, firstExpr.getString());
+    String defineName = firstExpr.getString();
+    if (defines.contains(defineName)) {
+      Node define = NodeUtil.newQName(compiler, ProcessDefines.getGlobalDefineAlias(defineName));
       Node defineStringValue = NodeUtil.newCallNode(IR.name("String"), define);
       return IR.comma(secondExpr, defineStringValue);
     } else {

src/com/google/javascript/jscomp/ProcessDefines.java

@@ -244,6 +244,31 @@ private void overrideDefines() {
 
           compiler.reportChangeToEnclosingScope(define.valueParent);
         }
+
+        // When requested, create a globally accessible alias for all define values. This will
+        // provide a hook for passes like J2clUtilGetDefineRewriterPass to read them in out-of-scope
+        // contexts.
+        if (J2clSourceFileChecker.shouldRunJ2clPasses(compiler)) {
+          String alias = getGlobalDefineAlias(define.defineName);
+          if (!alias.equals(define.defineName)) {
+            // If we had:
+            //  var x = goog.define('y', ...);
+            // we'll add an additional statement:
+            //  var goog$defines$y = x;
+            Node globalDefineName =
+                NodeUtil.newName(
+                    compiler, getGlobalDefineAlias(define.defineName), define.valueParent);
+            Node defineLhs =
+                define.valueParent.isAssign()
+                    ? define.valueParent.getFirstChild().cloneTree()
+                    : define.valueParent.cloneNode();
+            checkState(defineLhs.isName() || defineLhs.isQualifiedName(), defineLhs);
+            Node globalDefineVar =
+                IR.var(globalDefineName, defineLhs).srcrefTreeIfMissing(define.valueParent);
+            globalDefineVar.insertAfter(define.valueParent.getParent());
+            compiler.reportChangeToEnclosingScope(define.valueParent.getParent());
+          }
+        }
       }
     }
 
@@ -261,6 +286,17 @@ private void overrideDefines() {
     }
   }
 
+  static String getGlobalDefineAlias(String defineName) {
+    // Known defines are already globally accessible and may not be present in code. Therefore we'll
+    // reference them directly.
+    // goog.LOCALE is a special case as it's not processed as a define, it is instead
+    // late-substituted.
+    if (KNOWN_DEFINES.contains(defineName) || defineName.equals("goog.LOCALE")) {
+      return defineName;
+    }
+    return "jscomp$defines$" + defineName.replace('.', '$');
+  }
+
   /**
    * Returns the replacement value for a @define, if any.
    *
@@ -347,7 +383,11 @@ private void collectDefines(Node root) {
         }
       }
     }
-    compiler.setDefineNames(defineByDefineName.keySet());
+    compiler.setDefineNames(
+        ImmutableSet.<String>builder()
+            .addAll(KNOWN_DEFINES)
+            .addAll(defineByDefineName.keySet())
+            .build());
   }
 
   private @Nullable Ref selectDefineDeclaration(Name name) {

test/com/google/javascript/jscomp/J2clUtilGetDefineRewriterPassTest.java

@@ -53,7 +53,8 @@ public void testUtilGetDefine() {
             "var a = {};",
             "a.b = {}",
             "/** @define {boolean} */ a.b.c = true;",
-            "('def', String(a.b.c));"));
+            "var jscomp$defines$a$b$c = a.b.c;",
+            "('def', String(jscomp$defines$a$b$c));"));
     test(
         lines(
             "var a = {};",
@@ -64,7 +65,22 @@ public void testUtilGetDefine() {
             "var a = {};",
             "a.b = {}",
             "/** @define {boolean} */ a.b.c = true;",
-            "(null, String(a.b.c));"));
+            "var jscomp$defines$a$b$c = a.b.c;",
+            "(null, String(jscomp$defines$a$b$c));"));
+    test(
+        lines(
+            "/** @define {boolean} */ var x = goog.define('x', 1);",
+            "/** @define {boolean} */ var y = goog.define('y', x);",
+            "nativebootstrap.Util.$getDefine('x');",
+            "nativebootstrap.Util.$getDefine('y');"),
+        lines(
+            "/** @define {boolean} */ var x = 1;",
+            "var jscomp$defines$x = x;",
+            "/** @define {boolean} */ var y = x;",
+            "var jscomp$defines$y = y;",
+            "(null, String(jscomp$defines$x));",
+            "(null, String(jscomp$defines$y));"));
+    test(lines("nativebootstrap.Util.$getDefine('COMPILED');"), "(null, String(COMPILED));");
   }
 
   @Test

test/com/google/javascript/jscomp/ProcessDefinesTest.java

@@ -41,6 +41,8 @@ public ProcessDefinesTest() {
   private ProcessDefines.Mode mode;
   private boolean recognizeClosureDefines = true;
 
+  private boolean enableJ2clPasses = false;
+
   @Override
   @Before
   public void setUp() throws Exception {
@@ -55,6 +57,9 @@ public void setUp() throws Exception {
 
   @Override
   protected CompilerPass getProcessor(Compiler compiler) {
+    if (enableJ2clPasses) {
+      J2clSourceFileChecker.markToRunJ2clPasses(compiler);
+    }
     return new ProcessDefinesWithInjectedNamespace(compiler);
   }
 
@@ -940,6 +945,30 @@ public void testClosureDefinesErrors_enabledByRecognizeClosureDefines() {
     testSame("var CLOSURE_DEFINES = {'FOO': a};");
   }
 
+  @Test
+  public void testGenerateGlobalAliases() {
+    enableJ2clPasses = true;
+
+    test(
+        lines("var a = {};", "/** @define {number} */ a.b = goog.define('a.b', 1);"),
+        lines("var a = {};", "/** @define {number} */ a.b = 1;", "var jscomp$defines$a$b = a.b;"));
+    test(
+        lines("var a = {};", "/** @define {number} */ a.b = goog.define('c.d', 1);"),
+        lines("var a = {};", "/** @define {number} */ a.b = 1;", "var jscomp$defines$c$d = a.b;"));
+    test(
+        "/** @define {number} */ var a = goog.define('c.d', 1);",
+        lines("/** @define {number} */ var a = 1;", "var jscomp$defines$c$d = a;"));
+    test(
+        lines(
+            "/** @define {number} */ var a = goog.define('a', 1);",
+            "/** @define {number} */ var b = goog.define('b', a);"),
+        lines(
+            "/** @define {number} */ var a = 1;",
+            "var jscomp$defines$a = a;",
+            "/** @define {number} */ var b = a;",
+            "var jscomp$defines$b = b;"));
+  }
+
   private class ProcessDefinesWithInjectedNamespace implements CompilerPass {
     private final Compiler compiler;