src/share/classes/com/sun/tools/javac/main/JavaCompiler.java

@@ -361,10 +361,11 @@
             log.error("cant.access", ex.sym, ex.getDetailValue());
             if (ex instanceof ClassReader.BadClassFile)
                 throw new Abort();
         }
         source = Source.instance(context);
+        Target target = Target.instance(context);
         attr = Attr.instance(context);
         chk = Check.instance(context);
         gen = Gen.instance(context);
         flow = Flow.instance(context);
         transTypes = TransTypes.instance(context);

@@ -401,10 +402,12 @@
                         log.warning(LintCategory.OPTIONS, "source.no.bootclasspath", source.name);
                 }
             }
         }
 
+        checkForObsoleteOptions(target);
+
         verboseCompilePolicy = options.isSet("verboseCompilePolicy");
 
         if (attrParseOnly)
             compilePolicy = CompilePolicy.ATTR_ONLY;
         else

@@ -430,10 +433,30 @@
 
         if (options.isUnset("oldDiags"))
             log.setDiagnosticFormatter(RichDiagnosticFormatter.instance(context));
     }
 
+    private void checkForObsoleteOptions(Target target) {
+        // Unless lint checking on options is disabled, check for
+        // obsolete source and target options.
+        boolean obsoleteOptionFound = false;
+        if (options.isUnset(XLINT_CUSTOM, "-" + LintCategory.OPTIONS.option)) {
+            if (source.compareTo(Source.JDK1_5) <= 0) {
+                log.warning(LintCategory.OPTIONS, "option.obsolete.source", source.name);
+                obsoleteOptionFound = true;
+            }
+
+            if (target.compareTo(Target.JDK1_5) <= 0) {
+                log.warning(LintCategory.OPTIONS, "option.obsolete.target", source.name);
+                obsoleteOptionFound =true;
+            }
+
+            if (obsoleteOptionFound)
+                log.warning(LintCategory.OPTIONS, "option.obsolete.suppression");
+        }
+    }
+
     /* Switches:
      */
 
     /** Verbose output.
      */