diff options
| -rw-r--r-- | api/src/main/java/org/osjava/jardiff/Tools.java | 48 |
1 files changed, 44 insertions, 4 deletions
diff --git a/api/src/main/java/org/osjava/jardiff/Tools.java b/api/src/main/java/org/osjava/jardiff/Tools.java index 7ac6a42..41ba63c 100644 --- a/api/src/main/java/org/osjava/jardiff/Tools.java +++ b/api/src/main/java/org/osjava/jardiff/Tools.java @@ -65,6 +65,18 @@ public final class Tools return (value & mask) == 0; } + private static boolean isLessAccessPermitted(int oldAccess, int newAccess) { + if (has(newAccess, Opcodes.ACC_PUBLIC)) { + return false; + } else if (has(newAccess, Opcodes.ACC_PROTECTED)) { + return has(oldAccess, Opcodes.ACC_PUBLIC); + } else if (has(newAccess, Opcodes.ACC_PRIVATE)) { + return not(oldAccess, Opcodes.ACC_PRIVATE); + } else { + return has(oldAccess, Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED); + } + } + /** * @deprecated Use {@link #isClassAccessChange(int, int)}. */ @@ -118,6 +130,14 @@ public final class Tools * 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">13.4.7 Access to Members and Constructors</a><ul> + * <li>Changing the declared access of a member or constructor to permit less access + * <b>may break compatibility</b> with pre-existing binaries, causing a linkage error to be thrown when these binaries are resolved. + * </li> + * <li>The binary format is defined so that changing a member or constructor to be more accessible does not cause a + * linkage error when a subclass (already) defines a method to have less access. + * </li> + * </ul></li> * <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> @@ -155,13 +175,19 @@ public final class Tools * @return */ public static boolean isFieldAccessChange(final int oldAccess, final int newAccess) { + if (isLessAccessPermitted(oldAccess, newAccess)) { + return true; // 13.4.7 + } 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; + final int accessPermissions = Opcodes.ACC_PUBLIC | + Opcodes.ACC_PROTECTED | + Opcodes.ACC_PRIVATE; + final int oldAccess2 = oldAccess & ~compatibleChanges & ~accessPermissions; + final int newAccess2 = newAccess & ~compatibleChanges & ~accessPermissions; return oldAccess2 != newAccess2; } } @@ -170,6 +196,14 @@ public final class Tools * 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-13.4.9">13.4.7 Access to Members and Constructors</a><ul> + * <li>Changing the declared access of a member or constructor to permit less access + * <b>may break compatibility</b> with pre-existing binaries, causing a linkage error to be thrown when these binaries are resolved. + * </li> + * <li>The binary format is defined so that changing a member or constructor to be more accessible does not cause a + * linkage error when a subclass (already) defines a method to have less access. + * </li> + * </ul></li> * <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> @@ -210,6 +244,9 @@ public final class Tools * @return */ public static boolean isMethodAccessChange(final int oldAccess, final int newAccess) { + if (isLessAccessPermitted(oldAccess, newAccess)) { + return true; // 13.4.7 + } 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) && @@ -220,8 +257,11 @@ public final class Tools 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; + final int accessPermissions = Opcodes.ACC_PUBLIC | + Opcodes.ACC_PROTECTED | + Opcodes.ACC_PRIVATE; + final int oldAccess2 = oldAccess & ~compatibleChanges & ~accessPermissions; + final int newAccess2 = newAccess & ~compatibleChanges & ~accessPermissions; return oldAccess2 != newAccess2; } } |