src/jdk.compiler/share/classes/com/sun/tools/javac/parser/JavacParser.java

*** 90,99 ****
--- 90,102 ----
      private Source source;
  
      /** The name table. */
      private Names names;
  
+     /** The lint settings. */
+     private Lint lint;
+ 
      /** End position mappings container */
      protected final AbstractEndPosTable endPosTable;
  
      // Because of javac's limited lookahead, some contexts are ambiguous in
      // the presence of type annotations even though they are not ambiguous
*** 184,193 ****
--- 187,197 ----
          this.parseModuleInfo = parseModuleInfo;
          docComments = newDocCommentTable(keepDocComments, fac);
          this.keepLineMap = keepLineMap;
          this.errorTree = F.Erroneous();
          endPosTable = newEndPosTable(keepEndPositions);
+         this.lint = fac.lint;
      }
  
      protected AbstractEndPosTable newEndPosTable(boolean keepEndPositions) {
          return  keepEndPositions
                  ? new SimpleEndPosTable(this)
*** 637,647 ****
--- 641,654 ----
                  nextToken();
                  return names.error;
              }
          } else if (token.kind == UNDERSCORE) {
              if (allowUnderscoreIdentifier) {
+                 if (lint.isEnabled(Lint.LintCategory.FUTURE) &&
+                     !lint.isSuppressed(Lint.LintCategory.FUTURE)) {
                      warning(token.pos, "underscore.as.identifier");
+                 }
              } else {
                  error(token.pos, "underscore.as.identifier");
              }
              Name name = token.name();
              nextToken();