File:  [gforth] / gforth / vmgen-ex / mini.y
Revision 1.7: download - view: text, annotated - select for diffs
Mon Dec 31 19:02:25 2007 UTC (11 years, 10 months ago) by anton
Branches: MAIN
CVS tags: v0-7-0, HEAD
updated copyright year after changing license notice

    1: /* front-end compiler for vmgen example
    2: 
    3:   Copyright (C) 2001,2002,2003,2007 Free Software Foundation, Inc.
    4: 
    5:   This file is part of Gforth.
    6: 
    7:   Gforth is free software; you can redistribute it and/or
    8:   modify it under the terms of the GNU General Public License
    9:   as published by the Free Software Foundation, either version 3
   10:   of the License, or (at your option) any later version.
   11: 
   12:   This program is distributed in the hope that it will be useful,
   13:   but WITHOUT ANY WARRANTY; without even the implied warranty of
   14:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15:   GNU General Public License for more details.
   16: 
   17:   You should have received a copy of the GNU General Public License
   18:   along with this program; if not, see http://www.gnu.org/licenses/.
   19: */
   20: 
   21: /* I use yacc/bison here not because I think it's the best tool for
   22:    the job, but because it's widely available and popular; it's also
   23:    (barely) adequate for this job. */
   24: 
   25: %{
   26: #include <stdlib.h>
   27: #include <stdio.h>
   28: #include <string.h>
   29: #include "mini.h"
   30: 
   31: /* BB_BOUNDARY is needed on basic blocks without a preceding VM branch */
   32: #define BB_BOUNDARY (last_compiled = NULL,  /* suppress peephole opt */ \
   33:                      block_insert(vmcodep)) /* for accurate profiling */
   34: 
   35: Inst *vm_prim;
   36: Inst *vmcodep;
   37: FILE *vm_out;
   38: int vm_debug;
   39: 
   40: void yyerror(char *s)
   41: {
   42: #if 1
   43:   /* for pure flex call */
   44:   fprintf(stderr, "%s: %s\n", program_name, s);
   45: #else
   46:   /* lex or flex -l supports yylineno */
   47:   fprintf (stderr, "%s: %d: %s\n", program_name, yylineno, s);
   48: #endif
   49: }
   50: 
   51: #include "mini-gen.i"
   52: 
   53: void gen_main_end(void)
   54: {
   55:   gen_call(&vmcodep, func_addr("main"), func_calladjust("main"));
   56:   gen_end(&vmcodep);
   57:   BB_BOUNDARY; /* for profiling; see comment in mini.vmg:end */
   58: }
   59: 
   60: int locals=0;
   61: int nonparams=0;
   62: 
   63: int yylex();
   64: %}
   65: 
   66: 
   67: %token FUNC RETURN END VAR IF THEN ELSE WHILE DO BECOMES PRINT NUM IDENT
   68: 
   69: %union {
   70:   long num;
   71:   char *string;
   72:   Inst *instp;
   73: }
   74: 
   75: %type <string> IDENT;
   76: %type <num> NUM;
   77: %type <instp> elsepart;
   78: 
   79: 
   80: %%
   81: program: program function
   82:        | ;
   83: 
   84: function: FUNC IDENT { locals=0; nonparams=0; } '(' params ')' 
   85:           vars                  { insert_func($2,vmcodep,locals,nonparams); } 
   86:           stats RETURN expr ';'
   87:           END FUNC ';'          { gen_return(&vmcodep, -adjust(locals)); }
   88:         ;
   89: 
   90: params: IDENT ',' { insert_local($1); } params 
   91:       | IDENT     { insert_local($1); }
   92:       | ;
   93: 
   94: vars: vars VAR IDENT ';' { insert_local($3); nonparams++; }
   95:     | ;
   96: 
   97: stats: stats stat ';'
   98:      | ;
   99: 
  100: stat: IF expr THEN { gen_zbranch(&vmcodep, 0); $<instp>$ = vmcodep; }
  101:       stats { $<instp>$ = $<instp>4; } 
  102:       elsepart END IF { BB_BOUNDARY; $<instp>7[-1] = (Inst)vmcodep; }
  103:     | WHILE   { BB_BOUNDARY; $<instp>$ = vmcodep; } 
  104:       expr DO { gen_zbranch(&vmcodep, 0); $<instp>$ = vmcodep; }
  105:       stats END WHILE { gen_branch(&vmcodep, $<instp>2); $<instp>5[-1] = (Inst)vmcodep; }
  106:     | IDENT BECOMES expr	{ gen_storelocal(&vmcodep,  var_offset($1)); }
  107:     | PRINT expr		{ gen_print(&vmcodep); }
  108:     | expr                      { gen_drop(&vmcodep); }
  109:     ;
  110: 
  111: elsepart: ELSE { gen_branch(&vmcodep, 0); $<instp>$ = vmcodep; $<instp>0[-1] = (Inst)vmcodep; }
  112:           stats { $$ = $<instp>2; }
  113:         | { $$ = $<instp>0; }
  114:         ;
  115: 
  116: expr: term '+' term	 { gen_add(&vmcodep); }
  117:     | term '-' term	 { gen_sub(&vmcodep); }
  118:     | term '*' term	 { gen_mul(&vmcodep); }
  119:     | term '&' term	 { gen_and(&vmcodep); }
  120:     | term '|' term	 { gen_or(&vmcodep); }
  121:     | term '<' term	 { gen_lessthan(&vmcodep); }
  122:     | term '=' term	 { gen_equals(&vmcodep); }
  123:     | '!' term		 { gen_not(&vmcodep); }
  124:     | '-' term		 { gen_negate(&vmcodep); }
  125:     | term
  126:     ;
  127: 
  128: term: '(' expr ')'
  129:     | IDENT '(' args ')' { gen_call(&vmcodep, func_addr($1), func_calladjust($1)); }
  130:     | IDENT		 { gen_loadlocal(&vmcodep, var_offset($1)); }
  131:     | NUM		 { gen_lit(&vmcodep, $1); }
  132:     ;
  133: 
  134: /* missing: argument counting and checking against called function */
  135: args: expr ',' args
  136:     | expr 
  137:     | ;
  138: %%
  139: int yywrap(void)
  140: {
  141:   return 1;
  142: }
  143: 
  144: #include "lex.yy.c"

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>