CompilerUtils


1   /* ****************************************************************************
2    * CompilerUtils.java
3   * ****************************************************************************/
4   
5   /* J_LZ_COPYRIGHT_BEGIN *******************************************************
6   * Copyright 2001-2004 Laszlo Systems, Inc.  All Rights Reserved.              *
7   * Use is subject to license terms.                                            *
8   * J_LZ_COPYRIGHT_END *********************************************************/
9   
10  package org.openlaszlo.compiler;
11  
12  import org.openlaszlo.css.CSSParser;
13  import org.openlaszlo.sc.Function;
14  import org.openlaszlo.sc.ScriptCompiler;
15  import org.openlaszlo.utils.ChainedException;
16  
17  import java.io.*;
18  import java.util.*;
19  import org.jdom.Element;
20  import org.apache.log4j.*;
21  import java.text.DecimalFormat  ;
22  import java.text.FieldPosition  ;
23  
24  public class CompilerUtils  {
25      /** Return a string that can be included in a script to tell the
26       * script compiler that subsequent lines should be numbered
27       * relative to the beginning or end position of the source text
28       * for this element.
29       *
30       * @param start true if the location should be relative to the
31       * start of the element (otherwise it is relative to the end)
32       */
33      public static String   sourceLocationDirective(Element elt, boolean start) {
34          // Parser adds these attributes.
35          String   pathname = Parser.getSourceMessagePathname(elt);
36          Integer   lineno = Parser.getSourceLocation(elt, Parser.LINENO, start);
37          Integer   colno = Parser.getSourceLocation(elt, Parser.COLNO, start);
38          return sourceLocationDirective(pathname, lineno, colno);
39      }
40  
41      /** Return a string that can be used as a unique name for the
42       * element for compiler generated function names.
43       *
44       * @param start true if the location should be relative to the
45       * start of the element (otherwise it is relative to the end)
46       */
47      public static String   sourceUniqueName(Element elt, boolean start) {
48          // Parser adds these attributes.
49          String   pathname = Parser.getSourceMessagePathname(elt);
50          Integer   lineno = Parser.getSourceLocation(elt, Parser.LINENO, start);
51          Integer   colno = Parser.getSourceLocation(elt, Parser.COLNO, start);
52          // When parsing with crimson, the column number isn't defined.
53          // TODO: [2004-11-10] This won't generate unique names, so it
54          // will fail with krank.  Krank isn't used in this environment
55          // so that's okay for now.
56          if (colno.intValue() < 0)
57              colno = new Integer  (0);
58          
59          if (pathname == null) {
60              pathname = "unknown_file";
61          } else {
62              pathname = encodeJavaScriptIdentifier(pathname);
63          }
64          return "$" + pathname + '_' + lineno + '_' + colno;
65      }
66      
67      /** Returns a string that is a valid JavaScript identifier.
68       * Characters in the input string that are not valid in a
69       * JavaScript identifier are replaced by "$xx", where xx is the
70       * hex code of the character.  '$' is also replaced.  This is
71       * similar to URL encoding, except '$' is used as the quote
72       * character. */
73      public static String   encodeJavaScriptIdentifier(String   s) {
74          StringBuffer   buffer = new StringBuffer  ();
75          for (int i = 0; i < s.length(); i++) {
76              char c = s.charAt(i);
77              // Java and JavaScript identifiers have the same lexical
78              // specification, so the Java methods work for this
79              if (!(Character.isJavaIdentifierPart(c) ||
80                    (i == 0 && Character.isJavaIdentifierStart(c))) ||
81                  c == '$') {
82                  String   hex = Integer.toHexString((int) c);
83                  if (hex.length() < 2)
84                      hex = "0" + hex;
85                  buffer.append('$');
86                  buffer.append(hex.toUpperCase());
87              } else {
88                  buffer.append(c);
89              }
90          }
91          return buffer.toString();
92      }
93      
94      /* TODO: [2002-12-20 hqm] we need a better way to locate where
95       * an attribute occurs in a source file.
96       */
97      public static String   attributeLocationDirective(Element elt,
98                                                      String   attrname)
99      {
100         return sourceLocationDirective(elt, true);
101     }
102     
103     /** TODO: [2003-03-14 ptw] ditto */
104     public static String   attributeUniqueName(Element elt, String   attrname) {
105         return sourceUniqueName(elt, true);
106     }
107     
108     /** Return a string that can be included in a script to tell the
109      * script compiler that subsequent lines should be numbered
110      * relative to the beginning or end position of the source text
111      * for this element.
112      *
113      * @param start true if the location should be relative to the
114      * start of the element (otherwise it is relative to the end)
115      */
116     public static String   sourceLocationDirective(String   pathname,
117                                                  Integer   lineno,
118                                                  Integer   colno)
119     {
120         StringBuffer   buffer = new StringBuffer  ();
121         if (pathname != null) {
122             buffer.append("\n#file " + pathname + "\n");
123         }
124         if (lineno != null) {
125             // Set the line number of the following line.  Prepend a
126             // line feed, in case this directive is being added after
127             // other text.
128             if (buffer.length() == 0) {
129                 buffer.append('\n');
130             }
131             buffer.append("#line " + lineno + "\n");
132             // Add enough spaces to line the column of the following
133             // text up to the same position it had within the source
134             // text, so that the column numbers in source reporting
135             // are correct.
136             if (colno != null) {
137                 for (int i = colno.intValue(); i > 0; --i) {
138                     buffer.append(' ');
139                 }
140             }
141         }
142         return buffer.toString();
143     }
144     
145     public static String   sourceLocationPrettyString(Element elt) {
146         // Parser adds these attributes.
147         String   pathname = Parser.getSourceMessagePathname(elt);
148         Integer   lineno = Parser.getSourceLocation(elt, Parser.LINENO, true);
149         Integer   colno = Parser.getSourceLocation(elt, Parser.COLNO, true);
150         return pathname+":"+lineno+":"+colno;
151     }
152     
153     /** Returns true if the argument is at the top level of an lzx
154      * program: it is immediately within a canvas element, or within a
155      * library element that is itself at the top level. */
156     static boolean isAtToplevel(Element element) {
157         // To simplify the implementation, root canvas and library
158         // elements are also considered to be at the top level, as is
159         // a canvas inside a top level element.
160         Element parent = element.getParent();
161         return parent == null
162             || (ToplevelCompiler.isElement(parent) &&
163                 isAtToplevel(parent));
164     }
165 }
166
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