--- a/jdk/src/share/classes/sun/dyn/util/BytecodeName.java Wed Jul 05 17:38:31 2017 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,627 +0,0 @@
-/*
- * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package sun.dyn.util;
-
-/**
- * Utility routines for dealing with bytecode-level names.
- * Includes universal mangling rules for the JVM.
- *
- * <h3>Avoiding Dangerous Characters </h3>
- *
- * <p>
- * The JVM defines a very small set of characters which are illegal
- * in name spellings. We will slightly extend and regularize this set
- * into a group of <cite>dangerous characters</cite>.
- * These characters will then be replaced, in mangled names, by escape sequences.
- * In addition, accidental escape sequences must be further escaped.
- * Finally, a special prefix will be applied if and only if
- * the mangling would otherwise fail to begin with the escape character.
- * This happens to cover the corner case of the null string,
- * and also clearly marks symbols which need demangling.
- * </p>
- * <p>
- * Dangerous characters are the union of all characters forbidden
- * or otherwise restricted by the JVM specification,
- * plus their mates, if they are brackets
- * (<code><big><b>[</b></big></code> and <code><big><b>]</b></big></code>,
- * <code><big><b><</b></big></code> and <code><big><b>></b></big></code>),
- * plus, arbitrarily, the colon character <code><big><b>:</b></big></code>.
- * There is no distinction between type, method, and field names.
- * This makes it easier to convert between mangled names of different
- * types, since they do not need to be decoded (demangled).
- * </p>
- * <p>
- * The escape character is backslash <code><big><b>\</b></big></code>
- * (also known as reverse solidus).
- * This character is, until now, unheard of in bytecode names,
- * but traditional in the proposed role.
- *
- * </p>
- * <h3> Replacement Characters </h3>
- *
- *
- * <p>
- * Every escape sequence is two characters
- * (in fact, two UTF8 bytes) beginning with
- * the escape character and followed by a
- * <cite>replacement character</cite>.
- * (Since the replacement character is never a backslash,
- * iterated manglings do not double in size.)
- * </p>
- * <p>
- * Each dangerous character has some rough visual similarity
- * to its corresponding replacement character.
- * This makes mangled symbols easier to recognize by sight.
- * </p>
- * <p>
- * The dangerous characters are
- * <code><big><b>/</b></big></code> (forward slash, used to delimit package components),
- * <code><big><b>.</b></big></code> (dot, also a package delimiter),
- * <code><big><b>;</b></big></code> (semicolon, used in signatures),
- * <code><big><b>$</b></big></code> (dollar, used in inner classes and synthetic members),
- * <code><big><b><</b></big></code> (left angle),
- * <code><big><b>></b></big></code> (right angle),
- * <code><big><b>[</b></big></code> (left square bracket, used in array types),
- * <code><big><b>]</b></big></code> (right square bracket, reserved in this scheme for language use),
- * and <code><big><b>:</b></big></code> (colon, reserved in this scheme for language use).
- * Their replacements are, respectively,
- * <code><big><b>|</b></big></code> (vertical bar),
- * <code><big><b>,</b></big></code> (comma),
- * <code><big><b>?</b></big></code> (question mark),
- * <code><big><b>%</b></big></code> (percent),
- * <code><big><b>^</b></big></code> (caret),
- * <code><big><b>_</b></big></code> (underscore), and
- * <code><big><b>{</b></big></code> (left curly bracket),
- * <code><big><b>}</b></big></code> (right curly bracket),
- * <code><big><b>!</b></big></code> (exclamation mark).
- * In addition, the replacement character for the escape character itself is
- * <code><big><b>-</b></big></code> (hyphen),
- * and the replacement character for the null prefix is
- * <code><big><b>=</b></big></code> (equal sign).
- * </p>
- * <p>
- * An escape character <code><big><b>\</b></big></code>
- * followed by any of these replacement characters
- * is an escape sequence, and there are no other escape sequences.
- * An equal sign is only part of an escape sequence
- * if it is the second character in the whole string, following a backslash.
- * Two consecutive backslashes do <em>not</em> form an escape sequence.
- * </p>
- * <p>
- * Each escape sequence replaces a so-called <cite>original character</cite>
- * which is either one of the dangerous characters or the escape character.
- * A null prefix replaces an initial null string, not a character.
- * </p>
- * <p>
- * All this implies that escape sequences cannot overlap and may be
- * determined all at once for a whole string. Note that a spelling
- * string can contain <cite>accidental escapes</cite>, apparent escape
- * sequences which must not be interpreted as manglings.
- * These are disabled by replacing their leading backslash with an
- * escape sequence (<code><big><b>\-</b></big></code>). To mangle a string, three logical steps
- * are required, though they may be carried out in one pass:
- * </p>
- * <ol>
- * <li>In each accidental escape, replace the backslash with an escape sequence
- * (<code><big><b>\-</b></big></code>).</li>
- * <li>Replace each dangerous character with an escape sequence
- * (<code><big><b>\|</b></big></code> for <code><big><b>/</b></big></code>, etc.).</li>
- * <li>If the first two steps introduced any change, <em>and</em>
- * if the string does not already begin with a backslash, prepend a null prefix (<code><big><b>\=</b></big></code>).</li>
- * </ol>
- *
- * To demangle a mangled string that begins with an escape,
- * remove any null prefix, and then replace (in parallel)
- * each escape sequence by its original character.
- * <p>Spelling strings which contain accidental
- * escapes <em>must</em> have them replaced, even if those
- * strings do not contain dangerous characters.
- * This restriction means that mangling a string always
- * requires a scan of the string for escapes.
- * But then, a scan would be required anyway,
- * to check for dangerous characters.
- *
- * </p>
- * <h3> Nice Properties </h3>
- *
- * <p>
- * If a bytecode name does not contain any escape sequence,
- * demangling is a no-op: The string demangles to itself.
- * Such a string is called <cite>self-mangling</cite>.
- * Almost all strings are self-mangling.
- * In practice, to demangle almost any name “found in nature”,
- * simply verify that it does not begin with a backslash.
- * </p>
- * <p>
- * Mangling is a one-to-one function, while demangling
- * is a many-to-one function.
- * A mangled string is defined as <cite>validly mangled</cite> if
- * it is in fact the unique mangling of its spelling string.
- * Three examples of invalidly mangled strings are <code><big><b>\=foo</b></big></code>,
- * <code><big><b>\-bar</b></big></code>, and <code><big><b>baz\!</b></big></code>, which demangle to <code><big><b>foo</b></big></code>, <code><big><b>\bar</b></big></code>, and
- * <code><big><b>baz\!</b></big></code>, but then remangle to <code><big><b>foo</b></big></code>, <code><big><b>\bar</b></big></code>, and <code><big><b>\=baz\-!</b></big></code>.
- * If a language back-end or runtime is using mangled names,
- * it should never present an invalidly mangled bytecode
- * name to the JVM. If the runtime encounters one,
- * it should also report an error, since such an occurrence
- * probably indicates a bug in name encoding which
- * will lead to errors in linkage.
- * However, this note does not propose that the JVM verifier
- * detect invalidly mangled names.
- * </p>
- * <p>
- * As a result of these rules, it is a simple matter to
- * compute validly mangled substrings and concatenations
- * of validly mangled strings, and (with a little care)
- * these correspond to corresponding operations on their
- * spelling strings.
- * </p>
- * <ul>
- * <li>Any prefix of a validly mangled string is also validly mangled,
- * although a null prefix may need to be removed.</li>
- * <li>Any suffix of a validly mangled string is also validly mangled,
- * although a null prefix may need to be added.</li>
- * <li>Two validly mangled strings, when concatenated,
- * are also validly mangled, although any null prefix
- * must be removed from the second string,
- * and a trailing backslash on the first string may need escaping,
- * if it would participate in an accidental escape when followed
- * by the first character of the second string.</li>
- * </ul>
- * <p>If languages that include non-Java symbol spellings use this
- * mangling convention, they will enjoy the following advantages:
- * </p>
- * <ul>
- * <li>They can interoperate via symbols they share in common.</li>
- * <li>Low-level tools, such as backtrace printers, will have readable displays.</li>
- * <li>Future JVM and language extensions can safely use the dangerous characters
- * for structuring symbols, but will never interfere with valid spellings.</li>
- * <li>Runtimes and compilers can use standard libraries for mangling and demangling.</li>
- * <li>Occasional transliterations and name composition will be simple and regular,
- * for classes, methods, and fields.</li>
- * <li>Bytecode names will continue to be compact.
- * When mangled, spellings will at most double in length, either in
- * UTF8 or UTF16 format, and most will not change at all.</li>
- * </ul>
- *
- *
- * <h3> Suggestions for Human Readable Presentations </h3>
- *
- *
- * <p>
- * For human readable displays of symbols,
- * it will be better to present a string-like quoted
- * representation of the spelling, because JVM users
- * are generally familiar with such tokens.
- * We suggest using single or double quotes before and after
- * mangled symbols which are not valid Java identifiers,
- * with quotes, backslashes, and non-printing characters
- * escaped as if for literals in the Java language.
- * </p>
- * <p>
- * For example, an HTML-like spelling
- * <code><big><b><pre></b></big></code> mangles to
- * <code><big><b>\^pre\_</b></big></code> and could
- * display more cleanly as
- * <code><big><b>'<pre>'</b></big></code>,
- * with the quotes included.
- * Such string-like conventions are <em>not</em> suitable
- * for mangled bytecode names, in part because
- * dangerous characters must be eliminated, rather
- * than just quoted. Otherwise internally structured
- * strings like package prefixes and method signatures
- * could not be reliably parsed.
- * </p>
- * <p>
- * In such human-readable displays, invalidly mangled
- * names should <em>not</em> be demangled and quoted,
- * for this would be misleading. Likewise, JVM symbols
- * which contain dangerous characters (like dots in field
- * names or brackets in method names) should not be
- * simply quoted. The bytecode names
- * <code><big><b>\=phase\,1</b></big></code> and
- * <code><big><b>phase.1</b></big></code> are distinct,
- * and in demangled displays they should be presented as
- * <code><big><b>'phase.1'</b></big></code> and something like
- * <code><big><b>'phase'.1</b></big></code>, respectively.
- * </p>
- *
- * @author John Rose
- * @version 1.2, 02/06/2008
- * @see http://blogs.sun.com/jrose/entry/symbolic_freedom_in_the_vm
- */
-public class BytecodeName {
- private BytecodeName() { } // static only class
-
- /** Given a source name, produce the corresponding bytecode name.
- * The source name should not be qualified, because any syntactic
- * markers (dots, slashes, dollar signs, colons, etc.) will be mangled.
- * @param s the source name
- * @return a valid bytecode name which represents the source name
- */
- public static String toBytecodeName(String s) {
- String bn = mangle(s);
- assert((Object)bn == s || looksMangled(bn)) : bn;
- assert(s.equals(toSourceName(bn))) : s;
- return bn;
- }
-
- /** Given an unqualified bytecode name, produce the corresponding source name.
- * The bytecode name must not contain dangerous characters.
- * In particular, it must not be qualified or segmented by colon {@code ':'}.
- * @param s the bytecode name
- * @return the source name, which may possibly have unsafe characters
- * @throws IllegalArgumentException if the bytecode name is not {@link #isSafeBytecodeName safe}
- * @see #isSafeBytecodeName(java.lang.String)
- */
- public static String toSourceName(String s) {
- checkSafeBytecodeName(s);
- String sn = s;
- if (looksMangled(s)) {
- sn = demangle(s);
- assert(s.equals(mangle(sn))) : s+" => "+sn+" => "+mangle(sn);
- }
- return sn;
- }
-
- /**
- * Given a bytecode name from a classfile, separate it into
- * components delimited by dangerous characters.
- * Each resulting array element will be either a dangerous character,
- * or else a safe bytecode name.
- * (The safe name might possibly be mangled to hide further dangerous characters.)
- * For example, the qualified class name {@code java/lang/String}
- * will be parsed into the array {@code {"java", '/', "lang", '/', "String"}}.
- * The name {@code <init>} will be parsed into { '<', "init", '>'}}
- * The name {@code foo/bar$:baz} will be parsed into
- * {@code {"foo", '/', "bar", '$', ':', "baz"}}.
- * The name {@code ::\=:foo:\=bar\!baz} will be parsed into
- * {@code {':', ':', "", ':', "foo", ':', "bar:baz"}}.
- */
- public static Object[] parseBytecodeName(String s) {
- int slen = s.length();
- Object[] res = null;
- for (int pass = 0; pass <= 1; pass++) {
- int fillp = 0;
- int lasti = 0;
- for (int i = 0; i <= slen; i++) {
- int whichDC = -1;
- if (i < slen) {
- whichDC = DANGEROUS_CHARS.indexOf(s.charAt(i));
- if (whichDC < DANGEROUS_CHAR_FIRST_INDEX) continue;
- }
- // got to end of string or next dangerous char
- if (lasti < i) {
- // normal component
- if (pass != 0)
- res[fillp] = toSourceName(s.substring(lasti, i));
- fillp++;
- lasti = i+1;
- }
- if (whichDC >= DANGEROUS_CHAR_FIRST_INDEX) {
- if (pass != 0)
- res[fillp] = DANGEROUS_CHARS_CA[whichDC];
- fillp++;
- lasti = i+1;
- }
- }
- if (pass != 0) break;
- // between passes, build the result array
- res = new Object[fillp];
- if (fillp <= 1 && lasti == 0) {
- if (fillp != 0) res[0] = toSourceName(s);
- break;
- }
- }
- return res;
- }
-
- /**
- * Given a series of components, create a bytecode name for a classfile.
- * This is the inverse of {@link #parseBytecodeName(java.lang.String)}.
- * Each component must either be an interned one-character string of
- * a dangerous character, or else a safe bytecode name.
- * @param components a series of name components
- * @return the concatenation of all components
- * @throws IllegalArgumentException if any component contains an unsafe
- * character, and is not an interned one-character string
- * @throws NullPointerException if any component is null
- */
- public static String unparseBytecodeName(Object[] components) {
- Object[] components0 = components;
- for (int i = 0; i < components.length; i++) {
- Object c = components[i];
- if (c instanceof String) {
- String mc = toBytecodeName((String) c);
- if (i == 0 && components.length == 1)
- return mc; // usual case
- if ((Object)mc != c) {
- if (components == components0)
- components = components.clone();
- components[i] = c = mc;
- }
- }
- }
- return appendAll(components);
- }
- private static String appendAll(Object[] components) {
- if (components.length <= 1) {
- if (components.length == 1) {
- return String.valueOf(components[0]);
- }
- return "";
- }
- int slen = 0;
- for (Object c : components) {
- if (c instanceof String)
- slen += String.valueOf(c).length();
- else
- slen += 1;
- }
- StringBuilder sb = new StringBuilder(slen);
- for (Object c : components) {
- sb.append(c);
- }
- return sb.toString();
- }
-
- /**
- * Given a bytecode name, produce the corresponding display name.
- * This is the source name, plus quotes if needed.
- * If the bytecode name contains dangerous characters,
- * assume that they are being used as punctuation,
- * and pass them through unchanged.
- * Non-empty runs of non-dangerous characters are demangled
- * if necessary, and the resulting names are quoted if
- * they are not already valid Java identifiers, or if
- * they contain a dangerous character (i.e., dollar sign "$").
- * Single quotes are used when quoting.
- * Within quoted names, embedded single quotes and backslashes
- * are further escaped by prepended backslashes.
- *
- * @param s the original bytecode name (which may be qualified)
- * @return a human-readable presentation
- */
- public static String toDisplayName(String s) {
- Object[] components = parseBytecodeName(s);
- for (int i = 0; i < components.length; i++) {
- if (!(components[i] instanceof String))
- continue;
- String sn = (String) components[i];
- // note that the name is already demangled!
- //sn = toSourceName(sn);
- if (!isJavaIdent(sn) || sn.indexOf('$') >=0 ) {
- components[i] = quoteDisplay(sn);
- }
- }
- return appendAll(components);
- }
- private static boolean isJavaIdent(String s) {
- int slen = s.length();
- if (slen == 0) return false;
- if (!Character.isJavaIdentifierStart(s.charAt(0)))
- return false;
- for (int i = 1; i < slen; i++) {
- if (!Character.isJavaIdentifierPart(s.charAt(i)))
- return false;
- }
- return true;
- }
- private static String quoteDisplay(String s) {
- // TO DO: Replace wierd characters in s by C-style escapes.
- return "'"+s.replaceAll("['\\\\]", "\\\\$0")+"'";
- }
-
- private static void checkSafeBytecodeName(String s)
- throws IllegalArgumentException {
- if (!isSafeBytecodeName(s)) {
- throw new IllegalArgumentException(s);
- }
- }
-
- /**
- * Report whether a simple name is safe as a bytecode name.
- * Such names are acceptable in class files as class, method, and field names.
- * Additionally, they are free of "dangerous" characters, even if those
- * characters are legal in some (or all) names in class files.
- * @param s the proposed bytecode name
- * @return true if the name is non-empty and all of its characters are safe
- */
- public static boolean isSafeBytecodeName(String s) {
- if (s.length() == 0) return false;
- // check occurrences of each DANGEROUS char
- for (char xc : DANGEROUS_CHARS_A) {
- if (xc == ESCAPE_C) continue; // not really that dangerous
- if (s.indexOf(xc) >= 0) return false;
- }
- return true;
- }
-
- /**
- * Report whether a character is safe in a bytecode name.
- * This is true of any unicode character except the following
- * <em>dangerous characters</em>: {@code ".;:$[]<>/"}.
- * @param s the proposed character
- * @return true if the character is safe to use in classfiles
- */
- public static boolean isSafeBytecodeChar(char c) {
- return DANGEROUS_CHARS.indexOf(c) < DANGEROUS_CHAR_FIRST_INDEX;
- }
-
- private static boolean looksMangled(String s) {
- return s.charAt(0) == ESCAPE_C;
- }
-
- private static String mangle(String s) {
- if (s.length() == 0)
- return NULL_ESCAPE;
-
- // build this lazily, when we first need an escape:
- StringBuilder sb = null;
-
- for (int i = 0, slen = s.length(); i < slen; i++) {
- char c = s.charAt(i);
-
- boolean needEscape = false;
- if (c == ESCAPE_C) {
- if (i+1 < slen) {
- char c1 = s.charAt(i+1);
- if ((i == 0 && c1 == NULL_ESCAPE_C)
- || c1 != originalOfReplacement(c1)) {
- // an accidental escape
- needEscape = true;
- }
- }
- } else {
- needEscape = isDangerous(c);
- }
-
- if (!needEscape) {
- if (sb != null) sb.append(c);
- continue;
- }
-
- // build sb if this is the first escape
- if (sb == null) {
- sb = new StringBuilder(s.length()+10);
- // mangled names must begin with a backslash:
- if (s.charAt(0) != ESCAPE_C && i > 0)
- sb.append(NULL_ESCAPE);
- // append the string so far, which is unremarkable:
- sb.append(s.substring(0, i));
- }
-
- // rewrite \ to \-, / to \|, etc.
- sb.append(ESCAPE_C);
- sb.append(replacementOf(c));
- }
-
- if (sb != null) return sb.toString();
-
- return s;
- }
-
- private static String demangle(String s) {
- // build this lazily, when we first meet an escape:
- StringBuilder sb = null;
-
- int stringStart = 0;
- if (s.startsWith(NULL_ESCAPE))
- stringStart = 2;
-
- for (int i = stringStart, slen = s.length(); i < slen; i++) {
- char c = s.charAt(i);
-
- if (c == ESCAPE_C && i+1 < slen) {
- // might be an escape sequence
- char rc = s.charAt(i+1);
- char oc = originalOfReplacement(rc);
- if (oc != rc) {
- // build sb if this is the first escape
- if (sb == null) {
- sb = new StringBuilder(s.length());
- // append the string so far, which is unremarkable:
- sb.append(s.substring(stringStart, i));
- }
- ++i; // skip both characters
- c = oc;
- }
- }
-
- if (sb != null)
- sb.append(c);
- }
-
- if (sb != null) return sb.toString();
-
- return s.substring(stringStart);
- }
-
- static char ESCAPE_C = '\\';
- // empty escape sequence to avoid a null name or illegal prefix
- static char NULL_ESCAPE_C = '=';
- static String NULL_ESCAPE = ESCAPE_C+""+NULL_ESCAPE_C;
-
- static final String DANGEROUS_CHARS = "\\/.;:$[]<>"; // \\ must be first
- static final String REPLACEMENT_CHARS = "-|,?!%{}^_";
- static final int DANGEROUS_CHAR_FIRST_INDEX = 1; // index after \\
- static char[] DANGEROUS_CHARS_A = DANGEROUS_CHARS.toCharArray();
- static char[] REPLACEMENT_CHARS_A = REPLACEMENT_CHARS.toCharArray();
- static final Character[] DANGEROUS_CHARS_CA;
- static {
- Character[] dcca = new Character[DANGEROUS_CHARS.length()];
- for (int i = 0; i < dcca.length; i++)
- dcca[i] = Character.valueOf(DANGEROUS_CHARS.charAt(i));
- DANGEROUS_CHARS_CA = dcca;
- }
-
- static final long[] SPECIAL_BITMAP = new long[2]; // 128 bits
- static {
- String SPECIAL = DANGEROUS_CHARS + REPLACEMENT_CHARS;
- //System.out.println("SPECIAL = "+SPECIAL);
- for (char c : SPECIAL.toCharArray()) {
- SPECIAL_BITMAP[c >>> 6] |= 1L << c;
- }
- }
- static boolean isSpecial(char c) {
- if ((c >>> 6) < SPECIAL_BITMAP.length)
- return ((SPECIAL_BITMAP[c >>> 6] >> c) & 1) != 0;
- else
- return false;
- }
- static char replacementOf(char c) {
- if (!isSpecial(c)) return c;
- int i = DANGEROUS_CHARS.indexOf(c);
- if (i < 0) return c;
- return REPLACEMENT_CHARS.charAt(i);
- }
- static char originalOfReplacement(char c) {
- if (!isSpecial(c)) return c;
- int i = REPLACEMENT_CHARS.indexOf(c);
- if (i < 0) return c;
- return DANGEROUS_CHARS.charAt(i);
- }
- static boolean isDangerous(char c) {
- if (!isSpecial(c)) return false;
- return (DANGEROUS_CHARS.indexOf(c) >= DANGEROUS_CHAR_FIRST_INDEX);
- }
- static int indexOfDangerousChar(String s, int from) {
- for (int i = from, slen = s.length(); i < slen; i++) {
- if (isDangerous(s.charAt(i)))
- return i;
- }
- return -1;
- }
- static int lastIndexOfDangerousChar(String s, int from) {
- for (int i = Math.min(from, s.length()-1); i >= 0; i--) {
- if (isDangerous(s.charAt(i)))
- return i;
- }
- return -1;
- }
-
-
-}