libcb.c

一个编译器修改的例子

#include "libcb.h"

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX	1024
#define MAXSTR	"%1024s"


/* This is part of the runtime system. It is linked with the C code
 * the compiler produces when compiling Asterix source. It is not part
 * of the compiler itself.
 */

int cb_ReadLine(array *a)
{
    size_t size;
    char   str [MAX];

    if (fgets(str, MAX, stdin) == 0)
	return 0;

    size = strlen(str);
    delete_array(*a);
    *a	 = new_array(size, 1);
    memcpy((**a).data.c, str, size);

    return 1;
}


int cb_WriteLine(void)
{
    return putc('\n', stdout) == '\n';
}


int cb_ReadString(array *a)
{
    size_t size;
    char   str [MAX];

    if (scanf(MAXSTR, str) != 1)
	return 0;

    size = strlen(str);
    delete_array(*a);
    *a	 = new_array(size, 1);
    memcpy((**a).data.c, str, size);

    return 1;
}


int cb_WriteString(array a)
{
    unsigned i;

    if (a == 0)
	runtime_error( "WriteString is called with a NULL string");

    for (i = 0; i < a->size; i ++)
    {
	int ch = a->data.c [i];

	if (putc(ch, stdout) != (unsigned char) ch)
	    return 0;
    }

    return 1;
}


int cb_ReadInt(int *i)
{
    return scanf("%d", i) == 1;
}


int cb_WriteInt(int i)
{
    return printf("%d", i) >= 0;
}


int cb_ReadReal(double *d)
{
    return scanf("%lf", d) == 1;
}


int cb_WriteReal(double d)
{
    return printf("%f", d) >= 0;
}


int cb_ReadChar(char *c)
{
    return scanf("%c", c) == 1;
}


int cb_WriteChar(char c)
{
    return putc(c, stdout) == (unsigned char) c;
}


array cb_StringCopy(array orig)
{
    array copy;

    if (orig == 0)
	runtime_error( "StringCopy is called with a NULL string");

    copy = new_array(orig->size, 1);
    memcpy(copy->data.c, orig->data.c, orig->size);

    return copy;
}


int cb_StringToInt(array a)
{
    int value = 0, index;

    if (a == 0)
	runtime_error( "StringToInt is called with a NULL string");

    for (index = 0; index < a->size; index ++)
	if (!isdigit((int) a->data.c [index]))
	    break;
	else
	    value *= 10, value += a->data.c [index] - '0';

    return value;
}


array cb_IntToString(int i)
{
    size_t size;
    array  a;
    char   str [16];

    sprintf(str, "%d", i);
    size = strlen(str);
    a	 = new_array(size, 1);
    memcpy(a->data.c, str, size);

    return a;
}


array cb_RealToString(double d)
{
    size_t size;
    array  a;
    char   str [64];

    sprintf(str, "%g", d);
    size = strlen(str);
    a	 = new_array(size, 1);
    memcpy(a->data.c, str, size);

    return a;
}


double cb_StringToReal(array a)
{
    char str [MAX];

    if (a == 0)
	runtime_error( "StringToReal is called with a NULL string");

    if (a->size >= MAX)
	runtime_error("constant too large");

    memcpy(str, a->data.c, a->size);
    str [a->size] = '\0';
    return atof(str);
}


double cb_IntToReal(int i)
{
    return (double) i;
}


int cb_RealToInt(double d)
{
    return (int) d;
}


int cb_CharToInt(char c)
{
    return (int) c;
}


char cb_IntToChar(int i)
{
    return (char) i;
}


double cb_Random(void)
{
    return (double) rand() / RAND_MAX;
}