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package jdk.vm.ci.meta;

Miscellaneous collection of utility methods used by jdk.vm.ci.meta and its clients.
/** * Miscellaneous collection of utility methods used by {@code jdk.vm.ci.meta} and its clients. */
public class MetaUtil {
Extends the functionality of Class.getSimpleName() to include a non-empty string for anonymous and local classes.
Params:
  • clazz – the class for which the simple name is being requested
  • withEnclosingClass – specifies if the returned name should be qualified with the name(s) of the enclosing class/classes of clazz (if any). This option is ignored if clazz denotes an anonymous or local class.
Returns:the simple name
/** * Extends the functionality of {@link Class#getSimpleName()} to include a non-empty string for * anonymous and local classes. * * @param clazz the class for which the simple name is being requested * @param withEnclosingClass specifies if the returned name should be qualified with the name(s) * of the enclosing class/classes of {@code clazz} (if any). This option is ignored * if {@code clazz} denotes an anonymous or local class. * @return the simple name */
public static String getSimpleName(Class<?> clazz, boolean withEnclosingClass) { final String simpleName = safeSimpleName(clazz); if (simpleName.length() != 0) { if (withEnclosingClass) { String prefix = ""; Class<?> enclosingClass = clazz; while ((enclosingClass = enclosingClass.getEnclosingClass()) != null) { prefix = safeSimpleName(enclosingClass) + "." + prefix; } return prefix + simpleName; } return simpleName; } // Must be an anonymous or local class final String name = clazz.getName(); int index = name.indexOf('$'); if (index == -1) { return name; } index = name.lastIndexOf('.', index); if (index == -1) { return name; } return name.substring(index + 1); } private static String safeSimpleName(Class<?> clazz) { try { return clazz.getSimpleName(); } catch (InternalError e) { // Scala inner class names do not always start with '$', // causing Class.getSimpleName to throw an InternalError Class<?> enclosingClass = clazz.getEnclosingClass(); String fqn = clazz.getName(); if (enclosingClass == null) { // Should never happen given logic in // Class.getSimpleName but best be safe return fqn; } String enclosingFQN = enclosingClass.getName(); int length = fqn.length(); if (enclosingFQN.length() >= length) { // Should also never happen return fqn; } return fqn.substring(enclosingFQN.length()); } }
Converts a type name in internal form to an external form.
Params:
  • name – the internal name to convert
  • qualified – whether the returned name should be qualified with the package name
  • classForNameCompatible – specifies if the returned name for array types should be in Class.forName(String) format (e.g., "[Ljava.lang.Object;", "[[I") or in Java source code format (e.g., "java.lang.Object[]", "int[][]" ).
/** * Converts a type name in internal form to an external form. * * @param name the internal name to convert * @param qualified whether the returned name should be qualified with the package name * @param classForNameCompatible specifies if the returned name for array types should be in * {@link Class#forName(String)} format (e.g., {@code "[Ljava.lang.Object;"}, * {@code "[[I"}) or in Java source code format (e.g., {@code "java.lang.Object[]"}, * {@code "int[][]"} ). */
public static String internalNameToJava(String name, boolean qualified, boolean classForNameCompatible) { switch (name.charAt(0)) { case 'L': { String result = name.substring(1, name.length() - 1).replace('/', '.'); if (!qualified) { final int lastDot = result.lastIndexOf('.'); if (lastDot != -1) { result = result.substring(lastDot + 1); } } return result; } case '[': return classForNameCompatible ? name.replace('/', '.') : internalNameToJava(name.substring(1), qualified, classForNameCompatible) + "[]"; default: if (name.length() != 1) { throw new IllegalArgumentException("Illegal internal name: " + name); } return JavaKind.fromPrimitiveOrVoidTypeChar(name.charAt(0)).getJavaName(); } }
Convenient shortcut for calling appendLocation(StringBuilder, ResolvedJavaMethod, int) without having to supply a StringBuilder instance and convert the result to a string.
/** * Convenient shortcut for calling * {@link #appendLocation(StringBuilder, ResolvedJavaMethod, int)} without having to supply a * {@link StringBuilder} instance and convert the result to a string. */
public static String toLocation(ResolvedJavaMethod method, int bci) { return appendLocation(new StringBuilder(), method, bci).toString(); }
Appends a string representation of a location specified by a given method and bci to a given StringBuilder. If a stack trace element with a non-null file name and non-negative line number is available for the given method, then the string returned is the StackTraceElement.toString() value of the stack trace element, suffixed by the bci location. For example:
    java.lang.String.valueOf(String.java:2930) [bci: 12]
Otherwise, the string returned is the value of applying JavaMethod.format(String) with the format string "%H.%n(%p)", suffixed by the bci location. For example:
    java.lang.String.valueOf(int) [bci: 12]
Params:
  • sb –
  • method –
  • bci –
/** * Appends a string representation of a location specified by a given method and bci to a given * {@link StringBuilder}. If a stack trace element with a non-null file name and non-negative * line number is {@linkplain ResolvedJavaMethod#asStackTraceElement(int) available} for the * given method, then the string returned is the {@link StackTraceElement#toString()} value of * the stack trace element, suffixed by the bci location. For example: * * <pre> * java.lang.String.valueOf(String.java:2930) [bci: 12] * </pre> * * Otherwise, the string returned is the value of applying {@link JavaMethod#format(String)} * with the format string {@code "%H.%n(%p)"}, suffixed by the bci location. For example: * * <pre> * java.lang.String.valueOf(int) [bci: 12] * </pre> * * @param sb * @param method * @param bci */
public static StringBuilder appendLocation(StringBuilder sb, ResolvedJavaMethod method, int bci) { if (method != null) { StackTraceElement ste = method.asStackTraceElement(bci); if (ste.getFileName() != null && ste.getLineNumber() > 0) { sb.append(ste); } else { sb.append(method.format("%H.%n(%p)")); } } else { sb.append("Null method"); } return sb.append(" [bci: ").append(bci).append(']'); } static void appendProfile(StringBuilder buf, AbstractJavaProfile<?, ?> profile, int bci, String type, String sep) { if (profile != null) { AbstractProfiledItem<?>[] pitems = profile.getItems(); if (pitems != null) { buf.append(String.format("%s@%d:", type, bci)); for (int j = 0; j < pitems.length; j++) { AbstractProfiledItem<?> pitem = pitems[j]; buf.append(String.format(" %.6f (%s)%s", pitem.getProbability(), pitem.getItem(), sep)); } if (profile.getNotRecordedProbability() != 0) { buf.append(String.format(" %.6f <other %s>%s", profile.getNotRecordedProbability(), type, sep)); } else { buf.append(String.format(" <no other %s>%s", type, sep)); } } } }
Converts a Java source-language class name into the internal form.
Params:
  • className – the class name
Returns:the internal name form of the class name
/** * Converts a Java source-language class name into the internal form. * * @param className the class name * @return the internal name form of the class name */
public static String toInternalName(String className) { if (className.startsWith("[")) { /* Already in the correct array style. */ return className.replace('.', '/'); } StringBuilder result = new StringBuilder(); String base = className; while (base.endsWith("[]")) { result.append("["); base = base.substring(0, base.length() - 2); } switch (base) { case "boolean": result.append("Z"); break; case "byte": result.append("B"); break; case "short": result.append("S"); break; case "char": result.append("C"); break; case "int": result.append("I"); break; case "float": result.append("F"); break; case "long": result.append("J"); break; case "double": result.append("D"); break; case "void": result.append("V"); break; default: result.append("L").append(base.replace('.', '/')).append(";"); break; } return result.toString(); }
Gets a string representation of an object based soley on its class and its identity hash code. This avoids and calls to virtual methods on the object such as Object.hashCode().
/** * Gets a string representation of an object based soley on its class and its * {@linkplain System#identityHashCode(Object) identity hash code}. This avoids and calls to * virtual methods on the object such as {@link Object#hashCode()}. */
public static String identityHashCodeString(Object obj) { if (obj == null) { return "null"; } return obj.getClass().getName() + "@" + System.identityHashCode(obj); } }