1 /*

     2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package jdk.jshell;

    26 

    27 import java.util.Set;

    28 import java.util.stream.Collectors;

    29 import java.util.stream.Stream;

    30 

    31 /**

    32  * Within a String, mask code comments and ignored modifiers (within context).

    33  *

    34  * @author Robert Field

    35  */

    36 class MaskCommentsAndModifiers {

    37 

    38     private final static Set<String> IGNORED_MODIFERS =

    39             Stream.of( "public", "protected", "private", "static", "final" )

    40                     .collect( Collectors.toSet() );

    41 

    42     private final StringBuilder sbCleared = new StringBuilder();

    43     private final StringBuilder sbMask = new StringBuilder();

    44     private final String str;

    45     private final int length;

    46     private final boolean maskModifiers;

    47     private int next = 0;

    48     private boolean wasMasked = false;

    49     private boolean inside = false;

    50 

    51     @SuppressWarnings("empty-statement")

    52     public MaskCommentsAndModifiers(String s, boolean maskModifiers) {

    53         this.str = s;

    54         this.length = s.length();

    55         this.maskModifiers = maskModifiers;

    56         do { } while (next());

    57     }

    58 

    59     public String cleared() {

    60         return sbCleared.toString();

    61     }

    62 

    63     public String mask() {

    64         return sbMask.toString();

    65     }

    66 

    67     public boolean wasMasked() {

    68         return wasMasked;

    69     }

    70 

    71     /**

    72      * Read the next character

    73      */

    74     private int read() {

    75         if (next >= length) {

    76             return -1;

    77         }

    78         return str.charAt(next++);

    79     }

    80 

    81     private void write(StringBuilder sb, int ch) {

    82         sb.append((char)ch);

    83     }

    84 

    85     private void write(int ch) {

    86         write(sbCleared, ch);

    87         write(sbMask, Character.isWhitespace(ch) ? ch : ' ');

    88     }

    89 

    90     private void writeMask(int ch) {

    91         wasMasked = true;

    92         write(sbMask, ch);

    93         write(sbCleared, Character.isWhitespace(ch) ? ch : ' ');

    94     }

    95 

    96     private void write(CharSequence s) {

    97         for (int cp : s.chars().toArray()) {

    98             write(cp);

    99         }

   100     }

   101 

   102     private void writeMask(CharSequence s) {

   103         for (int cp : s.chars().toArray()) {

   104             writeMask(cp);

   105         }

   106     }

   107 

   108     private boolean next() {

   109         return next(read());

   110     }

   111 

   112     private boolean next(int c) {

   113         if (c < 0) {

   114             return false;

   115         }

   116 

   117         if (c == '\'' || c == '"') {

   118             inside = true;

   119             write(c);

   120             int match = c;

   121             c = read();

   122             while (c != match) {

   123                 if (c < 0) {

   124                     return false;

   125                 }

   126                 if (c == '\n' || c == '\r') {

   127                     write(c);

   128                     return true;

   129                 }

   130                 if (c == '\\') {

   131                     write(c);

   132                     c = read();

   133                 }

   134                 write(c);

   135                 c = read();

   136             }

   137             write(c);

   138             return true;

   139         }

   140 

   141         if (c == '/') {

   142             c = read();

   143             if (c == '*') {

   144                 writeMask('/');

   145                 writeMask(c);

   146                 int prevc = 0;

   147                 while ((c = read()) != '/' || prevc != '*') {

   148                     if (c < 0) {

   149                         return false;

   150                     }

   151                     writeMask(c);

   152                     prevc = c;

   153                 }

   154                 writeMask(c);

   155                 return true;

   156             } else if (c == '/') {

   157                 writeMask('/');

   158                 writeMask(c);

   159                 while ((c = read()) != '\n' && c != '\r') {

   160                     if (c < 0) {

   161                         return false;

   162                     }

   163                     writeMask(c);

   164                 }

   165                 writeMask(c);

   166                 return true;

   167             } else {

   168                 inside = true;

   169                 write('/');

   170                 // read character falls through

   171             }

   172         }

   173 

   174         if (Character.isJavaIdentifierStart(c)) {

   175             if (maskModifiers && !inside) {

   176                 StringBuilder sb = new StringBuilder();

   177                 do {

   178                     write(sb, c);

   179                     c = read();

   180                 } while (Character.isJavaIdentifierPart(c));

   181                 String id = sb.toString();

   182                 if (IGNORED_MODIFERS.contains(id)) {

   183                     writeMask(sb);

   184                 } else {

   185                     write(sb);

   186                     if (id.equals("import")) {

   187                         inside = true;

   188                     }

   189                 }

   190                 return next(c); // recurse to handle left-over character

   191             }

   192         } else if (!Character.isWhitespace(c)) {

   193             inside = true;

   194         }

   195 

   196         if (c < 0) {

   197             return false;

   198         }

   199         write(c);

   200         return true;

   201     }

   202 }