Rename GlobalVariables.put => define and ensure the variable was not defined before

Author: eregon

src/main/java/org/truffleruby/core/kernel/TruffleKernelNodes.java

@@ -25,13 +25,11 @@
 import org.truffleruby.language.RubyNode;
 import org.truffleruby.language.RubyRootNode;
 import org.truffleruby.language.control.RaiseException;
-import org.truffleruby.language.globals.GlobalVariableStorage;
 import org.truffleruby.language.globals.ReadSimpleGlobalVariableNode;
 import org.truffleruby.language.globals.WriteSimpleGlobalVariableNode;
 import org.truffleruby.language.loader.CodeLoader;
 import org.truffleruby.language.loader.FileLoader;
 import org.truffleruby.language.methods.DeclarationContext;
-import org.truffleruby.language.objects.shared.WriteBarrierNode;
 import org.truffleruby.language.threadlocal.FindThreadAndFrameLocalStorageNode;
 import org.truffleruby.language.threadlocal.FindThreadAndFrameLocalStorageNodeGen;
 import org.truffleruby.parser.ParserContext;
@@ -138,7 +136,7 @@ public abstract static class DefineHookedVariableInnerNode extends CoreMethodArr
         @TruffleBoundary
         @Specialization(guards = { "isRubySymbol(name)", "isRubyProc(getter)", "isRubyProc(setter)" })
         public DynamicObject defineHookedVariableInnerNode(DynamicObject name, DynamicObject getter, DynamicObject setter, DynamicObject isDefined) {
-            getContext().getCoreLibrary().getGlobalVariables().put(Layouts.SYMBOL.getString(name), getter, setter, isDefined);
+            getContext().getCoreLibrary().getGlobalVariables().define(Layouts.SYMBOL.getString(name), getter, setter, isDefined);
             return nil();
         }
 

src/main/java/org/truffleruby/language/TruffleBootNodes.java

@@ -165,14 +165,14 @@ private void setArgvGlobals(StringNodes.MakeStringNode makeStringNode) {
                     String key = global_values[i];
                     String value = global_values[i + 1];
 
-                    getContext().getCoreLibrary().getGlobalVariables().put(
+                    getContext().getCoreLibrary().getGlobalVariables().define(
                             "$" + key,
                             makeStringNode.executeMake(value, UTF8Encoding.INSTANCE, CodeRange.CR_UNKNOWN));
                 }
 
                 String[] global_flags = getContext().getOptions().ARGV_GLOBAL_FLAGS;
                 for (String flag : global_flags) {
-                    getContext().getCoreLibrary().getGlobalVariables().put("$" + flag, true);
+                    getContext().getCoreLibrary().getGlobalVariables().define("$" + flag, true);
                 }
             }
         }

src/main/java/org/truffleruby/language/globals/GlobalVariables.java

@@ -14,7 +14,6 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
@@ -45,17 +44,19 @@ public GlobalVariableReader getReader(String name) {
         return new GlobalVariableReader(this, name);
     }
 
-    public GlobalVariableStorage put(String name, Object value) {
-        assert !variables.containsKey(name);
-        final GlobalVariableStorage storage = new GlobalVariableStorage(value, defaultValue, null, null, null);
-        variables.put(name, storage);
-        return storage;
+    public GlobalVariableStorage define(String name, Object value) {
+        return define(name, new GlobalVariableStorage(value, defaultValue, null, null, null));
+    }
+
+    public GlobalVariableStorage define(String name, DynamicObject getter, DynamicObject setter, DynamicObject isDefined) {
+        return define(name, new GlobalVariableStorage(defaultValue, getter, setter, isDefined));
     }
 
-    public GlobalVariableStorage put(String name, DynamicObject getter, DynamicObject setter, DynamicObject isDefined) {
-        assert !variables.containsKey(name);
-        final GlobalVariableStorage storage = new GlobalVariableStorage(defaultValue, getter, setter, isDefined);
-        variables.put(name, storage);
+    private GlobalVariableStorage define(String name, GlobalVariableStorage storage) {
+        final GlobalVariableStorage previous = variables.putIfAbsent(name, storage);
+        if (previous != null) {
+            throw new IllegalArgumentException("Global variable $" + name + " is already defined");
+        }
         return storage;
     }