src/java.base/share/classes/jdk/internal/module/ClassFileAttributes.java

*** 738,743 ****
--- 738,821 ----
  
              return attr;
          }
      }
  
+ 
+     /**
+      *  ModuleResolution_attribute {
+      *    u2 attribute_name_index;    // "ModuleResolution"
+      *    u4 attribute_length;        // 2
+      *    u2 resolution_flags;
+      *
+      *  The value of the resolution_flags item is a mask of flags used to denote
+      *  properties of module resolution. The flags are as follows:
+      *
+      *   // Optional
+      *   0x0001 (DO_NOT_RESOLVE_BY_DEFAULT)
+      *
+      *   // At most one of:
+      *   0x0002 (WARN_DEPRECATED)
+      *   0x0004 (WARN_DEPRECATED_FOR_REMOVAL)
+      *   0x0008 (WARN_INCUBATING)
+      */
+     static class ModuleResolution extends Attribute {
+         private final boolean doNotResolveByDefault;
+         private final WarnIfResolvedReason warnIfResolvedReason;
+ 
+         ModuleResolution(boolean doNotResolveByDefault,
+                          WarnIfResolvedReason warnIfResolvedReason) {
+             super(MODULE_RESOLUTION);
+             this.doNotResolveByDefault= doNotResolveByDefault;
+             this.warnIfResolvedReason = warnIfResolvedReason;
+         }
+ 
+         ModuleResolution() {
+             this(false, WarnIfResolvedReason.NONE);
+         }
+ 
+         @Override
+         protected Attribute read(ClassReader cr,
+                                  int off,
+                                  int len,
+                                  char[] buf,
+                                  int codeOff,
+                                  Label[] labels)
+         {
+             int flags = cr.readUnsignedShort(off);
+ 
+             boolean doNotResolve = false;
+             if ((flags & DO_NOT_RESOLVE_BY_DEFAULT) != 0)
+                 doNotResolve = true;
+ 
+             WarnIfResolvedReason warnReason = WarnIfResolvedReason.NONE;
+             if ((flags & WARN_DEPRECATED) != 0)
+                 warnReason = WarnIfResolvedReason.DEPRECATED;
+             else if ((flags & WARN_DEPRECATED_FOR_REMOVAL) != 0)
+                 warnReason = WarnIfResolvedReason.DEPRECATED_FOR_REMOVAL;
+             else if ((flags & WARN_INCUBATING) != 0)
+                 warnReason = WarnIfResolvedReason.INCUBATING;
+ 
+             return new ModuleResolution(doNotResolve, warnReason);
+         }
+ 
+         @Override
+         protected ByteVector write(ClassWriter cw,
+                                    byte[] code,
+                                    int len,
+                                    int maxStack,
+                                    int maxLocals)
+         {
+             int flags = 0;
+             if (doNotResolveByDefault)
+                 flags |= DO_NOT_RESOLVE_BY_DEFAULT;
+ 
+             int reason = warnIfResolvedReason.classFileConstant();
+             if (reason != 0)
+                 flags |= reason;
+ 
+             ByteVector attr = new ByteVector();
+             attr.putShort(flags);
+             return attr;
+         }
+     }
  }