lib/generator.php

   1 <?php
   2 /*
   3   +---------------------------------------------------------------------------------+
   4   | Copyright (c) 2010 Haanga                                                       |
   5   +---------------------------------------------------------------------------------+
   6   | Redistribution and use in source and binary forms, with or without              |
   7   | modification, are permitted provided that the following conditions are met:     |
   8   | 1. Redistributions of source code must retain the above copyright               |
   9   |    notice, this list of conditions and the following disclaimer.                |
  10   |                                                                                 |
  11   | 2. Redistributions in binary form must reproduce the above copyright            |
  12   |    notice, this list of conditions and the following disclaimer in the          |
  13   |    documentation and/or other materials provided with the distribution.         |
  14   |                                                                                 |
  15   | 3. All advertising materials mentioning features or use of this software        |
  16   |    must display the following acknowledgement:                                  |
  17   |    This product includes software developed by César D. Rodas.                  |
  18   |                                                                                 |
  19   | 4. Neither the name of the César D. Rodas nor the                               |
  20   |    names of its contributors may be used to endorse or promote products         |
  21   |    derived from this software without specific prior written permission.        |
  22   |                                                                                 |
  23   | THIS SOFTWARE IS PROVIDED BY CÉSAR D. RODAS ''AS IS'' AND ANY                   |
  24   | EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED       |
  25   | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE          |
  26   | DISCLAIMED. IN NO EVENT SHALL CÉSAR D. RODAS BE LIABLE FOR ANY                  |
  27   | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES      |
  28   | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;    |
  29   | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND     |
  30   | ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT      |
  31   | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS   |
  32   | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE                     |
  33   +---------------------------------------------------------------------------------+
  34   | Authors: César Rodas <crodas@php.net>                                           |
  35   +---------------------------------------------------------------------------------+
  36 */
  37
  38 /**
  39  *  CodeGenerator class
  40  *
  41  *  This class takes the generated AST structure (arrays),
  42  *  and generated the PHP represantion.
  43  *
  44  *
  45  */
  46 class Haanga_CodeGenerator
  47 {
  48     protected $ident;
  49     protected $tab = "    ";
  50
  51     // getCode (AST $op_code) {{{
  52     /**
  53      *  Transform the AST generated by the Haanga_Compiler class
  54      *  and return the equivalent PHP code.
  55      *
  56      *  @param array $op_code
  57      *
  58      *  @return string
  59      */
  60     final function getCode($op_code)
  61     {
  62         $this->ident = 0;
  63         $code = "";
  64         foreach ($op_code as $op) {
  65             $method = "php_{$op['op']}";
  66             if (!is_callable(array($this, $method))) {
  67                 throw new Exception("CodeGenerator: Missing method $method");
  68             }
  69             switch ($op['op']) {
  70             case 'end_foreach':
  71             case 'end_if':
  72             case 'end_function':
  73             case 'else':
  74                 break;
  75             default:
  76                 $code .= $this->ident();
  77             }
  78             $code .= $this->$method($op);
  79         }
  80         return $code;
  81     }
  82     // }}}
  83
  84     // ident() {{{
  85     /**
  86      *  Get the string for the current tabulation
  87      *
  88      *  @return string
  89      */
  90     protected function ident()
  91     {
  92         $code = "\n";
  93         $code .= str_repeat($this->tab, $this->ident);
  94
  95         return $code;
  96     }
  97     // }}}
  98
  99     // php_else() {{{
 100     /**
 101      *  Return code for "else"
 102      *
 103      *  @return string
 104      */
 105     protected function php_else()
 106     {
 107         $this->ident--;
 108         $code = $this->ident()."} else {";
 109         $this->ident++;
 110         return $code;
 111     }
 112     // }}}
 113
 114     // php_comment() {{{
 115     /**
 116      *  Return code for "comments"
 117      *
 118      *  @return string
 119      */
 120     function php_comment($op)
 121     {
 122         return "/* {$op['comment']} */";
 123     }
 124     // }}}
 125
 126     // php_function(array $op) {{{
 127     /**
 128      *  Return the function declaration of the class, for now
 129      *  it has fixed params, this should change soon to generate
 130      *  any sort of functions
 131      *
 132      *  @return string
 133      */
 134     function php_function($op)
 135     {
 136         $code = "function {$op['name']}(\$vars, \$return=FALSE, \$blocks=array())".$this->ident()."{";
 137         $this->ident++;
 138         return $code;
 139     }
 140     // }}}
 141
 142     // php_if(array $op) {{{
 143     /**
 144      *  Return the "if" declaration and increase $this->ident
 145      *
 146      *  @return string
 147      */
 148     protected function php_if($op)
 149     {
 150         $code  = "if (".$this->php_generate_expr($op['expr']).") {";
 151         $this->ident++;
 152         return $code;
 153     }
 154     // }}}
 155
 156     // php_expr($op) {{{
 157     /**
 158      *  Return a stand-alone statement
 159      *
 160      *  @return string
 161      */
 162     protected function php_expr($op)
 163     {
 164         return $this->php_generate_expr($op[0]).";";
 165     }
 166     // }}}
 167
 168     // php_end_block() {{{
 169     /**
 170      *  Finish the current block (if, for, function, etc),
 171      *  return the final "}", and decrease $this->ident
 172      *
 173      *  @return string
 174      */
 175     protected function php_end_block()
 176     {
 177         $this->ident--;
 178         return $this->ident()."}";
 179     }
 180     // }}}
 181
 182     // php_end_function() {{{
 183     /**
 184      *  Return code to end a function
 185      *
 186      *  @return string
 187      */
 188     protected function php_end_function()
 189     {
 190         return $this->php_end_block();
 191     }
 192     // }}}
 193
 194     // php_end_if() {{{
 195     /**
 196      *  Return code to end a if
 197      *
 198      *  @return string
 199      */
 200     protected function php_end_if()
 201     {
 202         return $this->php_end_block();
 203     }
 204     // }}}
 205
 206     // php_end_foreach() {{{
 207     /**
 208      *  Return code to end a foreach
 209      *
 210      *  @return string
 211      */
 212     protected function php_end_foreach()
 213     {
 214         return $this->php_end_block();
 215     }
 216     // }}}
 217
 218     // php_foreach(array $op)  {{{
 219     /**
 220      *  Return the declaration of a "foreach" statement.
 221      *
 222      *  @return string
 223      */
 224     protected function php_foreach($op)
 225     {
 226         $op['array'] = $this->php_get_varname($op['array']);
 227         $op['value'] = $this->php_get_varname($op['value']);
 228         $code = "foreach ({$op['array']} as ";
 229         if (!isset($op['key'])) {
 230             $code .= " {$op['value']}";
 231         } else {
 232             $op['key'] = $this->php_get_varname($op['key']);
 233             $code     .= " {$op['key']} => {$op['value']}";
 234         }
 235
 236         $code .= ") {";
 237         $this->ident++;
 238         return $code;
 239     }
 240     // }}}
 241
 242     // php_append_var(array $op) {{{
 243     /**
 244      *  Return code to append something to a variable
 245      *
 246      *  @return string
 247      */
 248     protected function php_append_var($op)
 249     {
 250         return $this->php_declare($op, '.=');
 251     }
 252     // }}}
 253
 254     // php_exec($op) {{{
 255     /**
 256      *  Return code for a function calling.
 257      *
 258      *  @return string
 259      */
 260     protected function php_exec($op)
 261     {
 262         $code  = "";
 263         $code .= $op['name'].'(';
 264         if (isset($op['args'])) {
 265             $code .= $this->php_generate_list($op['args']);
 266         }
 267         $code .= ')';
 268         return $code;
 269     }
 270     // }}}
 271
 272     // php_generate_expr($op) {{{
 273     /**
 274      *  Return an expression
 275      *
 276      *  @return string
 277      */
 278     protected function php_generate_expr($expr)
 279     {
 280         $code = '';
 281         if (is_array($expr) && isset($expr['op_expr'])) {
 282             if ($expr['op_expr'] == 'expr') {
 283                 $code .= "(";
 284                 $code .= $this->php_generate_expr($expr[0]);
 285                 $code .= ")";
 286             } else {
 287                 $code .= $this->php_generate_expr($expr[0]);
 288                 $code .= " {$expr['op_expr']} ";
 289                 $code .= $this->php_generate_expr($expr[1]);
 290             }
 291         } else {
 292             if (is_array($expr)) {
 293                 $code .= $this->php_generate_stmt(array($expr));
 294             } else {
 295                 if ($expr === FALSE) {
 296                     $expr = 'FALSE';
 297                 } else if ($expr === TRUE) {
 298                     $expr = 'TRUE';
 299                 }
 300                 $code .= $expr;
 301             }
 302         }
 303         return $code;
 304     }
 305     // }}}
 306
 307     // php_generate_list(array ($array) {{{
 308     /**
 309      *  Return a list of expressions for parameters
 310      *  of a function
 311      *
 312      *  @return string
 313      */
 314     protected function php_generate_list($array)
 315     {
 316         $code = "";
 317         foreach ($array as $value) {
 318             $code .= $this->php_generate_stmt(array($value));
 319             $code .= ", ";
 320         }
 321         return substr($code, 0, -2);
 322     }
 323     // }}}
 324
 325     // php_generate_stmt(Array $op) {{{
 326     /**
 327      *  Return the representation of a statement
 328      *
 329      *  @return string
 330      */
 331     protected function php_generate_stmt($op)
 332     {
 333         $code = "";
 334
 335         for ($i=0; $i < count($op); $i++) {
 336             if (!isset($op[$i])) {
 337                 continue;
 338             }
 339             if (!is_Array($op[$i])) {
 340                 throw new Haanga_CompilerException("Malformed declaration ".print_r($op, TRUE));
 341             }
 342             $key   = key($op[$i]);
 343             $value = current($op[$i]);
 344             switch ($key) {
 345             case 'array':
 346                 $code .= "Array(";
 347                 $code .= $this->php_generate_list($value);
 348                 $code .= ")";
 349                 break;
 350             case 'function':
 351             case 'exec':
 352                 if (strlen($code) != 0 && $code[strlen($code) -1] != '.') {
 353                     $code .= '.';
 354                 }
 355
 356                 $value = array('name' => $value, 'args' => $op[$i]['args']);
 357                 $code .= $this->php_exec($value, FALSE);
 358                 $code .= '.';
 359                 break;
 360             case 'key':
 361                 $code .= $this->php_generate_stmt(array($value[0]))." => ".$this->php_generate_stmt(array($value[1]));
 362                 break;
 363             case 'string':
 364                 if ($code != "" && $code[strlen($code)-1] == '"') {
 365                     $code = substr($code, 0, -1);
 366                 } else {
 367                     $code .= '"';
 368                 }
 369                 $html  = addslashes($value);
 370                 $html  = str_replace(array('$', "\r", "\t", "\n","\\'"), array('\\$', '\r', '\t', '\n',"'"), $html);
 371                 $code .= $html.'"';
 372                 break;
 373             case 'var':
 374                 if (strlen($code) != 0 && $code[strlen($code) -1] != '.') {
 375                     $code .= '.';
 376                 }
 377                 $code .= $this->php_get_varname($value).'.';
 378                 break;
 379             case 'number':
 380                 if (!is_numeric($value)) {
 381                     throw new Exception("$value is not a valid number");
 382                 }
 383                 $code .= $value;
 384                 break;
 385             case 'op_expr':
 386                 if (strlen($code) != 0) {
 387                     $code .= '.';
 388                 }
 389                 $code .= $this->php_generate_expr($op[$i]);
 390                 $code .= ".";
 391                 break;
 392             case 'expr':
 393                 if (strlen($code) != 0) {
 394                     $code .= '.';
 395                 }
 396                 $code .= $this->php_generate_expr($value);
 397                 $code .= ".";
 398                 break;
 399             case 'expr_cond':
 400                 if (strlen($code) != 0) {
 401                     $code .= '.';
 402                 }
 403                 $code .= "(";
 404                 $code .= $this->php_generate_expr($value);
 405                 $code .= " ? ";
 406                 $code .= $this->php_generate_stmt(array($op[$i]['true']));
 407                 $code .= " : ";
 408                 $code .= $this->php_generate_stmt(array($op[$i]['false']));
 409                 $code .= ").";
 410                 break;
 411             case 'constant':
 412                 $code = $value;
 413                 break;
 414             default:
 415                 throw new Exception("Don't know how to declare {$key} = {$value} (".print_r($op[$i], TRUE));
 416             }
 417         }
 418
 419         if ($code != "" && $code[strlen($code)-1] == '.') {
 420             $code = substr($code, 0, -1);
 421         }
 422
 423         return $code;
 424     }
 425     // }}}
 426
 427     // php_print(array $op) {{{
 428     /**
 429      *  Return an echo of an stmt
 430      *
 431      *  @return string
 432      */
 433     protected function php_print($op)
 434     {
 435         return 'echo '.$this->php_generate_stmt($op).';';
 436     }
 437     // }}}
 438
 439     // php_inc(array $op) {{{
 440     /**
 441      *  Return increment a variable ($var++)
 442      *
 443      *  @return string
 444      */
 445     protected function php_inc($op)
 446     {
 447         return $this->php_get_varname($op['name'])."++;";
 448     }
 449     // }}}
 450
 451     // php_declare(array $op, $assign='=') {{{
 452     /**
 453      *  Return a variable declaration
 454      *
 455      *  @return string
 456      */
 457     protected function php_declare($op, $assign=' =')
 458     {
 459         $op['name'] = $this->php_get_varname($op['name']);
 460         $code = "{$op['name']} {$assign} ".$this->php_generate_stmt($op).";";
 461         return $code;
 462     }
 463     // }}}
 464
 465     // php_get_varname(mixed $var) {{{
 466     /**
 467      *  Return a variable
 468      *
 469      *  @param mixed $var
 470      *
 471      *  @return string
 472      */
 473     protected function php_get_varname($var)
 474     {
 475         if (is_array($var)) {
 476             if (!is_string($var[0])) {
 477                 if (count($var) == 1) {
 478                     return $this->php_get_varname($var[0]);
 479                 } else {
 480                     throw new Exception("Invalid variable definition ".print_r($var, TRUE));
 481                 }
 482             }
 483             $var_str = $this->php_get_varname($var[0]);
 484             for ($i=1; $i < count($var); $i++) {
 485                 $var_str .= "[";
 486                 if (is_string($var[$i])) {
 487                     $var_str .= '"'.$var[$i].'"';
 488                 } else if (is_array($var[$i])) {
 489                     if (isset($var[$i]['var'])) {
 490                         $var_str .= $this->php_get_varname($var[$i]['var']);
 491                     } else if (isset($var[$i]['string'])) {
 492                         $var_str .= '"'.addslashes($var[$i]['string']).'"';
 493                     }
 494                 }
 495                 $var_str .= "]";
 496             }
 497             return $var_str;
 498         } else {
 499             return "\$".$var;
 500         }
 501     }
 502     // }}}
 503
 504     // php_return($op) {{{
 505     /**
 506      *  Return "return"
 507      *
 508      *  @return string
 509      */
 510     protected function php_return($op)
 511     {
 512         $code = "return ".$this->php_generate_stmt($op).";";
 513         return $code;
 514     }
 515     // }}}
 516
 517 }
 518
 519 /*
 520  * Local variables:
 521  * tab-width: 4
 522  * c-basic-offset: 4
 523  * End:
 524  * vim600: sw=4 ts=4 fdm=marker
 525  * vim<600: sw=4 ts=4
 526  */