diff options
Diffstat (limited to 'src/core')
-rw-r--r-- | src/core/lombok/bytecode/ClassFileMetaData.java | 83 |
1 files changed, 78 insertions, 5 deletions
diff --git a/src/core/lombok/bytecode/ClassFileMetaData.java b/src/core/lombok/bytecode/ClassFileMetaData.java index 693a9ad5..618ba8f0 100644 --- a/src/core/lombok/bytecode/ClassFileMetaData.java +++ b/src/core/lombok/bytecode/ClassFileMetaData.java @@ -25,8 +25,10 @@ import java.util.ArrayList; import java.util.Collections; import java.util.List; +/** + * Utility to read the constant pool, header, and inheritance information of any class file. + */ public class ClassFileMetaData { - private static final byte UTF8 = 1; private static final byte INTEGER = 3; private static final byte FLOAT = 4; @@ -119,14 +121,31 @@ public class ClassFileMetaData { return result.toString(); } + /** + * Checks if the constant pool contains the provided 'raw' string. These are used as source material for further JVM types, such as string constants, type references, etcetera. + */ public boolean containsUtf8(String value) { return findUtf8(value) != NOT_FOUND; } + /** + * Checks if the constant pool contains a reference to the provided class. + * + * NB: Most uses of a type do <em>NOT</em> show up as a class in the constant pool. + * For example, the parameter types and return type of any method you invoke or declare, are stored as signatures and not as type references, + * but the type to which any method you invoke belongs, is. Read the JVM Specification for more information. + * + * @param className must be provided JVM-style, such as {@code java/lang/String} + */ public boolean usesClass(String className) { return findClass(className) != NOT_FOUND; } + /** + * Checks if the constant pool contains a reference to a given field, either for writing or reading. + * + * @param className must be provided JVM-style, such as {@code java/lang/String} + */ public boolean usesField(String className, String fieldName) { int classIndex = findClass(className); if (classIndex == NOT_FOUND) return false; @@ -142,6 +161,11 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains a reference to a given method, with any signature (return type and parameter types). + * + * @param className must be provided JVM-style, such as {@code java/lang/String} + */ public boolean usesMethod(String className, String methodName) { int classIndex = findClass(className); if (classIndex == NOT_FOUND) return false; @@ -157,6 +181,12 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains a reference to a given method. + * + * @param className must be provided JVM-style, such as {@code java/lang/String} + * @param descriptor must be provided JVM-style, such as {@code (IZ)Ljava/lang/String;} + */ public boolean usesMethod(String className, String methodName, String descriptor) { int classIndex = findClass(className); if (classIndex == NOT_FOUND) return false; @@ -171,6 +201,11 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains the provided string constant, which implies the constant is used somewhere in the code. + * + * NB: String literals get concatenated by the compiler. + */ public boolean containsStringConstant(String value) { int index = findUtf8(value); if (index == NOT_FOUND) return false; @@ -180,6 +215,11 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains the provided long constant, which implies the constant is used somewhere in the code. + * + * NB: compile-time constant expressions are evaluated at compile time. + */ public boolean containsLong(long value) { for (int i = 1; i < maxPoolSize; i++) { if (types[i] == LONG && readLong(i) == value) return true; @@ -187,6 +227,11 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains the provided double constant, which implies the constant is used somewhere in the code. + * + * NB: compile-time constant expressions are evaluated at compile time. + */ public boolean containsDouble(double value) { boolean isNan = Double.isNaN(value); for (int i = 1; i < maxPoolSize; i++) { @@ -198,6 +243,11 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains the provided int constant, which implies the constant is used somewhere in the code. + * + * NB: compile-time constant expressions are evaluated at compile time. + */ public boolean containsInteger(int value) { for (int i = 1; i < maxPoolSize; i++) { if (types[i] == INTEGER && readInteger(i) == value) return true; @@ -205,6 +255,11 @@ public class ClassFileMetaData { return false; } + /** + * Checks if the constant pool contains the provided float constant, which implies the constant is used somewhere in the code. + * + * NB: compile-time constant expressions are evaluated at compile time. + */ public boolean containsFloat(float value) { boolean isNan = Float.isNaN(value); for (int i = 1; i < maxPoolSize; i++) { @@ -230,7 +285,7 @@ public class ClassFileMetaData { private long readInteger(int index) { return read32(offsets[index]); } - + private float readFloat(int index) { return Float.intBitsToFloat(read32(offsets[index])); } @@ -238,15 +293,27 @@ public class ClassFileMetaData { private int read32(int pos) { return (byteCode[pos] & 0xFF) << 24 | (byteCode[pos + 1] & 0xFF) << 16 | (byteCode[pos + 2] & 0xFF) << 8 | (byteCode[pos + 3] &0xFF); } - + + /** + * Returns the name of the class in JVM format, such as {@code java/lang/String} + */ public String getClassName() { return getClassName(readValue(endOfPool + 2)); } + /** + * Returns the name of the superclass in JVM format, such as {@code java/lang/Object} + * + * NB: If you try this on Object itself, you'll get {@code null}.<br /> + * NB2: For interfaces and annotation interfaces, you'll always get {@code java/lang/Object} + */ public String getSuperClassName() { return getClassName(readValue(endOfPool + 4)); } + /** + * Returns the name of all implemented interfaces. + */ public List<String> getInterfaces() { int size = readValue(endOfPool + 6); if (size == 0) return Collections.emptyList(); @@ -258,10 +325,16 @@ public class ClassFileMetaData { return result; } + /** + * A {@code toString()} like utility to dump all contents of the constant pool into a string. + * + * NB: No guarantees are made about the exact layout of this string. It is for informational purposes only, don't try to parse it.<br /> + * NB2: After a double or long, there's a JVM spec-mandated gap, which is listed as {@code (cont.)} in the returned string. + */ public String poolContent() { StringBuilder result = new StringBuilder(); for (int i = 1; i < maxPoolSize; i++) { - result.append(String.format("#%02d: ", i)); + result.append(String.format("#%02x: ", i)); int pos = offsets[i]; switch(types[i]) { case UTF8: @@ -359,4 +432,4 @@ public class ClassFileMetaData { private int readValue(int position) { return ((byteCode[position] & 0xFF) << 8) | (byteCode[position + 1] & 0xFF); } -}
\ No newline at end of file +} |