diff options
Diffstat (limited to 'api/src/main/java/org/osjava/jardiff/Tools.java')
| -rw-r--r-- | api/src/main/java/org/osjava/jardiff/Tools.java | 175 |
1 files changed, 162 insertions, 13 deletions
diff --git a/api/src/main/java/org/osjava/jardiff/Tools.java b/api/src/main/java/org/osjava/jardiff/Tools.java index e159541..7ac6a42 100644 --- a/api/src/main/java/org/osjava/jardiff/Tools.java +++ b/api/src/main/java/org/osjava/jardiff/Tools.java @@ -32,20 +32,20 @@ public final class Tools private Tools() { /* empty */ } - + /** * Get the java class name given an internal class name. * This method currently replaces all instances of $ and / with . this * may not be according to the java language spec, and will almost * certainly fail for some inner classes. - * + * * @param internalName The internal name of the class. * @return The java class name. */ public static final String getClassName(String internalName) { - StringBuffer ret = new StringBuffer(internalName.length()); + final StringBuffer ret = new StringBuffer(internalName.length()); for (int i = 0; i < internalName.length(); i++) { - char ch = internalName.charAt(i); + final char ch = internalName.charAt(i); switch (ch) { case '$': case '/': @@ -58,22 +58,171 @@ public final class Tools return ret.toString(); } + private static boolean has(final int value, final int mask) { + return (value & mask) != 0; + } + private static boolean not(final int value, final int mask) { + return (value & mask) == 0; + } + /** - * Returns whether newAccess is incompatible with oldAccess + * @deprecated Use {@link #isClassAccessChange(int, int)}. + */ + public static boolean isAccessChange(int oldAccess, int newAccess) { + return isClassAccessChange(oldAccess, newAccess); + } + + /** + * Returns whether a class's newAccess is incompatible with oldAccess + * following <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html">Java Language Specification, Java SE 7 Edition</a>: + * <ul> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.1">13.4.1 abstract Classes</a><ul> + * <li>If a class that was not declared abstract is changed to be declared abstract, + * then pre-existing binaries that attempt to create new instances of that class + * will throw either an InstantiationError at link time, + * or (if a reflective method is used) an InstantiationException at run time. + * Such changes <b>break backward compatibility</b>!</li> + * <li>Changing a class that is declared abstract to no longer be declared abstract + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.2">13.4.2 final Classes</a><ul> + * <li>If a class that was not declared final is changed to be declared final, + * then a VerifyError is thrown if a binary of a pre-existing subclass of this class is loaded, + * because final classes can have no subclasses. + * Such changes <b>break functional backward compatibility</b>!</li> + * <li>Changing a class that is declared final to no longer be declared final + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * </ul></li> + * </ul> * * @param oldAccess * @param newAccess * @return */ - public static boolean isAccessChange(int oldAccess, int newAccess) { - if ((oldAccess & Opcodes.ACC_FINAL) == 0 && (newAccess & Opcodes.ACC_FINAL) > 0) { - return true; - } else if ((oldAccess & Opcodes.ACC_ABSTRACT) == 0 && (newAccess & Opcodes.ACC_ABSTRACT) > 0) { - return true; + public static boolean isClassAccessChange(final int oldAccess, final int newAccess) { + if ( not(oldAccess, Opcodes.ACC_ABSTRACT) && has(newAccess, Opcodes.ACC_ABSTRACT) ) { + return true; // 13.4.1 #1 + } else if ( not(oldAccess, Opcodes.ACC_FINAL) && has(newAccess, Opcodes.ACC_FINAL) ) { + return true; // 13.4.2 #1 + } else { + final int compatibleChanges = Opcodes.ACC_ABSTRACT | // 13.4.1 #2 + Opcodes.ACC_FINAL ; // 13.4.2 #2 + // FIXME Opcodes.ACC_VOLATILE ? + final int oldAccess2 = oldAccess & ~compatibleChanges; + final int newAccess2 = newAccess & ~compatibleChanges; + return oldAccess2 != newAccess2; + } + } + + /** + * Returns whether a field's newAccess is incompatible with oldAccess + * following <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html">Java Language Specification, Java SE 7 Edition</a>: + * <ul> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.9">13.4.9 final Fields and Constants</a><ul> + * <li>If a field that was not declared final is changed to be declared final, + * then it <b>can break compatibility</b> with pre-existing binaries that attempt to assign new values to the field.</li> + * <li>Deleting the keyword final or changing the value to which a <i>non-final</i> field is initialized + * <b>does not break compatibility</b> with existing binaries.</li> + * <li>If a field is a constant variable (§4.12.4), + * then deleting the keyword final or changing its value + * will <i>not break compatibility</i> with pre-existing binaries by causing them not to run, + * but they will not see any new value for the usage of the field unless they are recompiled. + * This is true even if the usage itself is not a compile-time constant expression (§15.28). + * Such changes <b>break functional backward compatibility</b>!</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.10">13.4.10 static Fields</a><ul> + * <li>If a field that is not declared private was not declared static + * and is changed to be declared static, or vice versa, + * then a linkage error, specifically an IncompatibleClassChangeError, + * will result if the field is used by a pre-existing binary which expected a field of the other kind. + * Such changes <b>break backward compatibility</b>!</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.11">13.4.11. transient Fields </a><ul> + * <li>Adding or deleting a transient modifier of a field + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * </ul></li> + * <li><a href="http://www.wsu.edu/UNIX_Systems/java/langspec-1.0/13.doc.html#45194">13.4.11 volatile Fields (JLS 1.0)</a><ul> + * <li>If a field that is not declared private was not declared volatile + * and is changed to be declared volatile, or vice versa, then a linkage time error, + * specifically an IncompatibleClassChangeError, may result if the field is used + * by a preexisting binary that expected a field of the opposite volatility. + * Such changes <b>break backward compatibility</b>!</li> + * </ul></li> + * </ul> + * + * @param oldAccess + * @param newAccess + * @return + */ + public static boolean isFieldAccessChange(final int oldAccess, final int newAccess) { + if ( not(oldAccess, Opcodes.ACC_FINAL) && has(newAccess, Opcodes.ACC_FINAL) ) { + return true; // 13.4.9 #1 + } else { + final int compatibleChanges = Opcodes.ACC_FINAL | // 13.4.9 #2 + Opcodes.ACC_TRANSIENT; // 13.4.11 #1 + final int oldAccess2 = oldAccess & ~compatibleChanges; + final int newAccess2 = newAccess & ~compatibleChanges; + return oldAccess2 != newAccess2; + } + } + + /** + * Returns whether a method's newAccess is incompatible with oldAccess + * following <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html">Java Language Specification, Java SE 7 Edition</a>: + * <ul> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.16">13.4.16 abstract Methods</a><ul> + * <li>Changing a method that is declared abstract to no longer be declared abstract + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * <li>Changing a method that is not declared abstract to be declared abstract + * <b>will break compatibility</b> with pre-existing binaries that previously invoked the method, causing an AbstractMethodError.</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.17">13.4.17 final</a><ul> + * <li>Changing a method that is declared final to no longer be declared final + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * <li>Changing an instance method that is not declared final to be declared final + * <b>may break compatibility</b> with existing binaries that depend on the ability to override the method.</li> + * <li>Changing a class (static) method that is not declared final to be declared final + * <b>does not break compatibility</b> with existing binaries, because the method could not have been overridden.</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.18">13.4.18 native Methods</a><ul> + * <li>Adding or deleting a native modifier of a method + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.19">13.4.19 static Methods</a><ul> + * <li>If a method that is not declared private is also declared static (that is, a class method) + * and is changed to not be declared static (that is, to an instance method), or vice versa, + * then <i>compatibility with pre-existing binaries may be broken</i>, resulting in a linkage time error, + * namely an IncompatibleClassChangeError, if these methods are used by the pre-existing binaries. + * Such changes <b>break functional backward compatibility</b>!</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.20">13.4.20 synchronized Methods</a><ul> + * <li>Adding or deleting a synchronized modifier of a method + * <b>does not break compatibility</b> with pre-existing binaries.</li> + * </ul></li> + * <li><a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-13.html#jls-13.4.21">13.4.21 Method and Constructor Throws</a><ul> + * <li>Changes to the throws clause of methods or constructors + * <b>do not break compatibility</b> with pre-existing binaries; these clauses are checked only at compile time.</li> + * </ul></li> + * </ul> + * + * @param oldAccess + * @param newAccess + * @return + */ + public static boolean isMethodAccessChange(final int oldAccess, final int newAccess) { + if ( not(oldAccess, Opcodes.ACC_ABSTRACT) && has(newAccess, Opcodes.ACC_ABSTRACT) ) { + return true; // 13.4.16 #2 + } else if ( not(oldAccess, Opcodes.ACC_FINAL) && not(oldAccess, Opcodes.ACC_STATIC) && + has(newAccess, Opcodes.ACC_FINAL) ) { + return true; // 13.4.17 #2 excluding and #3 } else { - oldAccess = oldAccess & ~Opcodes.ACC_FINAL & ~Opcodes.ACC_ABSTRACT; - newAccess = newAccess & ~Opcodes.ACC_FINAL & ~Opcodes.ACC_ABSTRACT; + final int compatibleChanges = Opcodes.ACC_ABSTRACT | // 13.4.16 #1 + Opcodes.ACC_FINAL | // 13.4.17 #1 + Opcodes.ACC_NATIVE | // 13.4.18 #1 + Opcodes.ACC_SYNCHRONIZED; // 13.4.20 #1 + final int oldAccess2 = oldAccess & ~compatibleChanges; + final int newAccess2 = newAccess & ~compatibleChanges; + return oldAccess2 != newAccess2; } - return oldAccess != newAccess; } } |