parse.c

/*

 This code was written as part of the CMU Common Lisp project at
 Carnegie Mellon University, and has been placed in the public domain.

*/

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

#include "lisp.h"
#include "internals.h"
#include "globals.h"
#include "vars.h"
#include "parse.h"
#include "os.h"
#include "interrupt.h"
#include "lispregs.h"
#include "monitor.h"
#include "arch.h"
#include "search.h"

/*
 * What platforms DON'T have strcasecmp nowadays?  Enable this if you
 * don't have it.
 */
#if 0

static int
strcasecmp(s1, s2)
     char *s1, *s2;
{
    int c1, c2;

    do {
	c1 = (*s1++);
	if (isupper(c1))
	    c1 = tolower(c1);

	c2 = (*s2++);
	if (isupper(c2))
	    c2 = tolower(c2);
    } while (c1 == c2 && c1 != 0);

    return c1 - c2;
}

#endif

static void
skip_ws(char **ptr)
{
    while (**ptr <= ' ' && **ptr != '\0')
	(*ptr)++;
}

static boolean
string_to_long(char *token, long *value)
{
    int base, digit;
    long num;
    char *ptr;

    if (token == 0)
	return FALSE;

    if (token[0] == '0')
	if (token[1] == 'x') {
	    base = 16;
	    token += 2;
	} else {
	    base = 8;
	    token++;
    } else if (token[0] == '#') {
	switch (token[1]) {
	  case 'x':
	  case 'X':
	      base = 16;
	      token += 2;
	      break;
	  case 'o':
	  case 'O':
	      base = 8;
	      token += 2;
	      break;
	  default:
	      return FALSE;
	}
    } else
	base = 10;

    num = 0;
    ptr = token;
    while (*ptr != '\0') {
	if (*ptr >= 'a' && *ptr <= 'f')
	    digit = *ptr + 10 - 'a';
	else if (*ptr >= 'A' && *ptr <= 'F')
	    digit = *ptr + 10 - 'A';
	else if (*ptr >= '0' && *ptr <= '9')
	    digit = *ptr - '0';
	else
	    return FALSE;
	if (digit < 0 || digit >= base)
	    return FALSE;

	ptr++;
	num = num * base + digit;
    }

    *value = num;
    return TRUE;
}

static boolean
lookup_variable(char *name, lispobj * result)
{
    struct var *var = lookup_by_name(name);

    if (var == NULL)
	return FALSE;
    else {
	*result = var_value(var);
	return TRUE;
    }
}


boolean
more_p(char **ptr)
{
    skip_ws(ptr);

    if (**ptr == '\0')
	return FALSE;
    else
	return TRUE;
}

char *
parse_token(char **ptr)
{
    char *token;

    skip_ws(ptr);

    if (**ptr == '\0')
	return NULL;

    token = *ptr;

    while (**ptr > ' ')
	(*ptr)++;

    if (**ptr != '\0') {
	**ptr = '\0';
	(*ptr)++;
    }

    return token;
}

#if 0
static boolean
number_p(token)
     char *token;
{
    char *okay;

    if (token == NULL)
	return FALSE;

    okay = "abcdefABCDEF987654321d0";

    if (token[0] == '0')
	if (token[1] == 'x' || token[1] == 'X')
	    token += 2;
	else {
	    token++;
	    okay += 14;
    } else if (token[0] == '#') {
	switch (token[1]) {
	  case 'x':
	  case 'X':
	      break;
	  case 'o':
	  case 'O':
	      okay += 14;
	      break;
	  default:
	      return FALSE;
	}
    } else
	okay += 12;

    while (*token != '\0')
	if (index(okay, *token++) == NULL)
	    return FALSE;
    return TRUE;
}
#endif

long
parse_number(char **ptr)
{
    char *token = parse_token(ptr);
    long result;

    if (token == NULL) {
	printf("Expected a number.\n");
	throw_to_monitor();
    } else if (string_to_long(token, &result))
	return result;
    else {
	printf("Invalid number: ``%s''\n", token);
	throw_to_monitor();
    }
    return 0;
}

char *
parse_addr(char **ptr)
{
    char *token = parse_token(ptr);
    long result;

    if (token == NULL) {
	printf("Expected an address.\n");
	throw_to_monitor();
    } else if (token[0] == '$') {
	if (!lookup_variable(token + 1, (lispobj *) & result)) {
	    printf("Unknown variable: ``%s''\n", token);
	    throw_to_monitor();
	}
	result &= ~7;
    } else {
	if (!string_to_long(token, &result)) {
	    printf("Invalid number: ``%s''\n", token);
	    throw_to_monitor();
	}
	result &= ~3;
    }

    if (!valid_addr((os_vm_address_t) result)) {
	printf("Invalid address: 0x%lx\n", result);
	throw_to_monitor();
    }

    return (char *) result;
}

static boolean
lookup_symbol(char *name, lispobj * result)
{
    int count;
    lispobj *headerptr;

    /* Search static space */
    headerptr = static_space;
    count = ((lispobj *) SymbolValue(STATIC_SPACE_FREE_POINTER) - static_space);
    if (search_for_symbol(name, &headerptr, &count)) {
	*result = (lispobj) headerptr | type_OtherPointer;
	return TRUE;
    }

    /* Search dynamic space */
    headerptr = current_dynamic_space;
#if !defined(ibmrt) && !defined(i386) && !defined(__x86_64)
    count = current_dynamic_space_free_pointer - current_dynamic_space;
#else
    count = (lispobj *) SymbolValue(ALLOCATION_POINTER) - current_dynamic_space;
#endif
    if (search_for_symbol(name, &headerptr, &count)) {
	*result = (lispobj) headerptr | type_OtherPointer;
	return TRUE;
    }

    return FALSE;
}

static int
parse_regnum(char *s)
{
    if ((s[1] == 'R') || (s[1] == 'r')) {
	int regnum;

	if (s[2] == '\0')
	    return -1;

	/* skip the $R part and call atoi on the number */
	regnum = atoi(s + 2);
	if ((regnum >= 0) && (regnum < NREGS))
	    return regnum;
	else
	    return -1;
    } else {
	int i;

	for (i = 0; i < NREGS; i++)
	    if (strcasecmp(s + 1, lisp_register_names[i]) == 0)
#ifdef i386
		return i * 2;
#else
		return i;
#endif

	return -1;
    }
}

lispobj
parse_lispobj(char **ptr)
{
    char *token = parse_token(ptr);
    long pointer;
    lispobj result;

    if (token == NULL) {
	printf("Expected an object.\n");
	throw_to_monitor();
    } else if (token[0] == '$') {
	if (isalpha(token[1])) {
	    int free;
	    int regnum;
	    os_context_t *context;

	    free = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX) >> 2;

	    if (free == 0) {
		printf
		    ("Variable ``%s'' is not valid -- there is no current interrupt context.\n",
		     token);
		throw_to_monitor();
	    }

	    context = lisp_interrupt_contexts[free - 1];

	    regnum = parse_regnum(token);
	    if (regnum < 0) {
		printf("Bogus register: ``%s''\n", token);
		throw_to_monitor();
	    }

	    result = SC_REG(context, regnum);
	} else if (!lookup_variable(token + 1, &result)) {
	    printf("Unknown variable: ``%s''\n", token);
	    throw_to_monitor();
	}
    } else if (token[0] == '@') {
	if (string_to_long(token + 1, &pointer)) {
	    pointer &= ~3;
	    if (valid_addr((os_vm_address_t) pointer))
		result = *(lispobj *) pointer;
	    else {
		printf("Invalid address: ``%s''\n", token + 1);
		throw_to_monitor();
	    }
	} else {
	    printf("Invalid address: ``%s''\n", token + 1);
	    throw_to_monitor();
	}
    } else if (string_to_long(token, (long *) &result));
    else if (lookup_symbol(token, &result));
    else {
	printf("Invalid lisp object: ``%s''\n", token);
	throw_to_monitor();
    }

    return result;
}