calc_yacc.c

利用flex和bison做的简易C语言编译器核心 支持C语言的大部分运算操作和语法,但是没有 变量声明和函数声明 适合制作虚拟机之类的 输出结果是伪汇编代码 我会继续更新

	    YYSIZE_T yyalloc = 2 * yysize;
	    if (! (yysize <= yyalloc && yyalloc <= YYSTACK_ALLOC_MAXIMUM))
	      yyalloc = YYSTACK_ALLOC_MAXIMUM;
	    if (yymsg != yymsgbuf)
	      YYSTACK_FREE (yymsg);
	    yymsg = (char *) YYSTACK_ALLOC (yyalloc);
	    if (yymsg)
	      yymsg_alloc = yyalloc;
	    else
	      {
		yymsg = yymsgbuf;
		yymsg_alloc = sizeof yymsgbuf;
	      }
	  }

	if (0 < yysize && yysize <= yymsg_alloc)
	  {
	    (void) yysyntax_error (yymsg, yystate, yychar);
	    yyerror (yymsg);
	  }
	else
	  {
	    yyerror (YY_("syntax error"));
	    if (yysize != 0)
	      goto yyexhaustedlab;
	  }
      }
#endif
    }



  if (yyerrstatus == 3)
    {
      /* If just tried and failed to reuse look-ahead token after an
	 error, discard it.  */

      if (yychar <= YYEOF)
	{
	  /* Return failure if at end of input.  */
	  if (yychar == YYEOF)
	    YYABORT;
	}
      else
	{
	  yydestruct ("Error: discarding",
		      yytoken, &yylval);
	  yychar = YYEMPTY;
	}
    }

  /* Else will try to reuse look-ahead token after shifting the error
     token.  */
  goto yyerrlab1;


/*---------------------------------------------------.
| yyerrorlab -- error raised explicitly by YYERROR.  |
`---------------------------------------------------*/
yyerrorlab:

  /* Pacify compilers like GCC when the user code never invokes
     YYERROR and the label yyerrorlab therefore never appears in user
     code.  */
  if (/*CONSTCOND*/ 0)
     goto yyerrorlab;

  /* Do not reclaim the symbols of the rule which action triggered
     this YYERROR.  */
  YYPOPSTACK (yylen);
  yylen = 0;
  YY_STACK_PRINT (yyss, yyssp);
  yystate = *yyssp;
  goto yyerrlab1;


/*-------------------------------------------------------------.
| yyerrlab1 -- common code for both syntax error and YYERROR.  |
`-------------------------------------------------------------*/
yyerrlab1:
  yyerrstatus = 3;	/* Each real token shifted decrements this.  */

  for (;;)
    {
      yyn = yypact[yystate];
      if (yyn != YYPACT_NINF)
	{
	  yyn += YYTERROR;
	  if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)
	    {
	      yyn = yytable[yyn];
	      if (0 < yyn)
		break;
	    }
	}

      /* Pop the current state because it cannot handle the error token.  */
      if (yyssp == yyss)
	YYABORT;


      yydestruct ("Error: popping",
		  yystos[yystate], yyvsp);
      YYPOPSTACK (1);
      yystate = *yyssp;
      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  *++yyvsp = yylval;


  /* Shift the error token.  */
  YY_SYMBOL_PRINT ("Shifting", yystos[yyn], yyvsp, yylsp);

  yystate = yyn;
  goto yynewstate;


/*-------------------------------------.
| yyacceptlab -- YYACCEPT comes here.  |
`-------------------------------------*/
yyacceptlab:
  yyresult = 0;
  goto yyreturn;

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  yyresult = 1;
  goto yyreturn;

#ifndef yyoverflow
/*-------------------------------------------------.
| yyexhaustedlab -- memory exhaustion comes here.  |
`-------------------------------------------------*/
yyexhaustedlab:
  yyerror (YY_("memory exhausted"));
  yyresult = 2;
  /* Fall through.  */
#endif

yyreturn:
  if (yychar != YYEOF && yychar != YYEMPTY)
     yydestruct ("Cleanup: discarding lookahead",
		 yytoken, &yylval);
  /* Do not reclaim the symbols of the rule which action triggered
     this YYABORT or YYACCEPT.  */
  YYPOPSTACK (yylen);
  YY_STACK_PRINT (yyss, yyssp);
  while (yyssp != yyss)
    {
      yydestruct ("Cleanup: popping",
		  yystos[*yyssp], yyvsp);
      YYPOPSTACK (1);
    }
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
#if YYERROR_VERBOSE
  if (yymsg != yymsgbuf)
    YYSTACK_FREE (yymsg);
#endif
  /* Make sure YYID is used.  */
  return YYID (yyresult);
}


#line 174 "calc_yacc.y"


Node * var_id(char *vs)
{
    Node *p_node;

    p_node = (Node *)malloc(sizeof(Node));

    p_node->node_data.id.s_label = vs;

    p_node->node_type = TYPE_EXPR_ID;

    return(p_node);
}

Node * con_cs(char *vs)
{
    Node *p_node;

    p_node = (Node *)malloc(sizeof(Node));

    p_node->node_data.cs.s_value = vs;

    p_node->node_type = TYPE_EXPR_CS;

    return(p_node);
}

Node * con_cc(char vc)
{
    Node *p_node;

    p_node = (Node *)malloc(sizeof(Node));

    p_node->node_data.cc.c_value = vc;

    p_node->node_type = TYPE_EXPR_CC;

    return(p_node);
}

Node * con_ci(long vi)
{
    Node *p_node;

    p_node = (Node *)malloc(sizeof(Node));

    p_node->node_data.ci.i_value = vi;

    p_node->node_type = TYPE_EXPR_CI;

    return(p_node);
}

Node * con_cr(Real vr)
{
    Node *p_node;

    p_node = (Node *)malloc(sizeof(Node));

    p_node->node_data.cr.r_value = vr;

    p_node->node_type = TYPE_EXPR_CR;

    return(p_node);
}

Node * ass_op(long op, char *va, Node *ex)
{
    Node *p_node;

    p_node = (Node *)malloc(sizeof(Node));

    p_node->node_data.op.oper = op;
    p_node->node_data.op.op_n = 2;
    p_node->node_data.op.op_s[0] = var_id(va);
    p_node->node_data.op.op_s[1] = ex;

    p_node->node_type = TYPE_EXPR_OP;

    return(p_node);
}

Node * exp_op(long op, long np, ...)
{
    Node *p_node;

    va_list ap;

    int ai;

    p_node = (Node *)malloc(sizeof(Node));

    va_start(ap, np);

    for(ai = 0; ai < np && ai < 4; ai ++)
    {
        p_node->node_data.op.op_s[ai] =
                va_arg(ap, Node *);
    }

    va_end(ap);

    p_node->node_data.op.oper = op;
    p_node->node_data.op.op_n = ai;

    p_node->node_type = TYPE_EXPR_OP;

    return(p_node);
}

void cc_cleanup(Node *p_node)
{
    if(NULL != p_node)
    {
        if(TYPE_EXPR_OP == p_node->node_type)
        {
            int i;

            for(i = 0; i < p_node->node_data.op.op_n; i ++)
            {
                cc_cleanup(p_node->node_data.op.op_s[i]);
            }
        }
        else
        if(TYPE_EXPR_ID == p_node->node_type)
        {
            if(NULL != p_node->node_data.id.s_label)
                  free(p_node->node_data.id.s_label);
        }
        else
        if(TYPE_EXPR_CS == p_node->node_type)
        {
            if(NULL != p_node->node_data.cs.s_value)
                  free(p_node->node_data.cs.s_value);
        }

        free(p_node);
    }
}

long cc_builder(Node *p_node)
{
    if(NULL != p_node)
    {
        switch(p_node->node_type)
        {
        case TYPE_EXPR_ID:
            fprintf(asout,"push_v %s\n", p_node->node_data.id.s_label);
            break;

        case TYPE_EXPR_CS:
            fprintf(asout,"push_s %s\n", p_node->node_data.cs.s_value);
            break;

        case TYPE_EXPR_CC:
            fprintf(asout,"push_c %c\n", p_node->node_data.cc.c_value);
            break;

        case TYPE_EXPR_CI:
            fprintf(asout,"push_i %d\n", p_node->node_data.ci.i_value);
            break;

        case TYPE_EXPR_CR:
            fprintf(asout,"push_r %e\n", p_node->node_data.cr.r_value);
            break;

        case TYPE_EXPR_OP:
            switch(p_node->node_data.op.oper)
            {
            case IFX:
                if(p_node->node_data.op.op_n > 2)
                {
                    char m_LabStrA[16];
                    char m_LabStrB[16];

                    /*if else*/
                    cc_builder(p_node->node_data.op.op_s[0]);

                    zzlabel(m_LabStrA);
                    fprintf(asout, "jump_z %s\n", m_LabStrA);

                    cc_builder(p_node->node_data.op.op_s[1]);

                    zzlabel(m_LabStrB);
                    fprintf(asout, "jump   %s\n", m_LabStrB);

                    fprintf(asout, "label: %s\n", m_LabStrA);

                    cc_builder(p_node->node_data.op.op_s[2]);

                    fprintf(asout, "label: %s\n", m_LabStrB);
                }
                else
                {
                    char m_LabStrA[16];

                    /*if then*/
                    cc_builder(p_node->node_data.op.op_s[0]);

                    zzlabel(m_LabStrA);
                    fprintf(asout, "jump_z %s\n", m_LabStrA);

                    cc_builder(p_node->node_data.op.op_s[1]);

                    fprintf(asout, "label: %s\n", m_LabStrA);
                }
                break;

            case GOTO:
                fprintf(asout,"jump   %s\n", p_node->
                        node_data.op.op_s[0]->
                        node_data.id.s_label);
                break;

            case LABE:
                fprintf(asout,"label: %s\n", p_node->
                        node_data.op.op_s[0]->
                        node_data.id.s_label);

                cc_builder(p_node->node_data.op.op_s[1]);
                break;

            case DO: /* do ... while(...); */
            	{
                    char m_LabStrA[16];

	            	zzlabel(m_LabStrA);
	            	fprintf(asout, "label: %s\n", m_LabStrA);

	            	cc_builder(p_node->node_data.op.op_s[0]);

	            	cc_builder(p_node->node_data.op.op_s[1]);

	            	fprintf(asout, "jump_n %s\n", m_LabStrA);
            	}
            	break;

            case WH: /* while(...) ...     */
            	{
                    char m_LabStrA[16];
                    char m_LabStrB[16];

					zzlabel(m_LabStrA);
	            	fprintf(asout, "label: %s\n", m_LabStrA);

	            	cc_builder(p_node->node_data.op.op_s[0]);

	            	zzlabel(m_LabStrB);
	            	fprintf(asout, "jump_z %s\n", m_LabStrB);

	            	cc_builder(p_node->node_data.op.op_s[1]);

	            	fprintf(asout, "jump   %s\n", m_LabStrA);

	            	fprintf(asout, "label: %s\n", m_LabStrB);
            	}
            	break;

            case CALL:
                {   int i = cc_builder(p_node->node_data.op.op_s[1]);

                    fprintf(asout,"push_i %d\n",i);

                    fprintf(asout,"call_f %s\n", p_node->
                             node_data.op.op_s[0]->
                             node_data.id.s_label);
                }
                break;

            case ',':
                {   int i = cc_builder(p_node->node_data.op.op_s[0]);
                    int j = cc_builder(p_node->node_data.op.op_s[1]);

                    return(i + j);
                }
                break;

            case ';':
                cc_builder(p_node->node_data.op.op_s[0]);
                fprintf(