#define W while#define S strspn #define R return #define F fprintf(stderr,#define C continue;#include <stdlib.h>#include <stdio.h>#include <string.h>#include <sys/stat.h>#ifndef RULES#define RULES	500#endif#define N(p, i)	(p += i, p += S(p, w), i = strcspn(p, w))char *b, l[BUFSIZ], *t[RULES], *d[RULES], *c[RULES], w[] = "\n\t ";time_t M();int T();void U();time_tM(f)char *f;{	int j, x;	size_t i = 0;	struct stat s;	N(f, i);	x = f[i];	f[i] = 0; 	j = stat(f, &s);	f[i] = x;	R j < 0 ? 0 : s.st_mtime;}intT(f)char *f;{	char *q;	size_t i = 0, j, k = 1;	N(f, i);	W ((q = t[k])) {		j = 0;		W (N(q, j)) {			if (i == j && !strncmp(f, q, i))				R k;		}		++k;	}	R 0;}voidU(f)char *f;{	time_t t = M(f);	size_t i = 0, j = !t, k = T(f);	char *p = d[k], *q = c[k];	if (!N(p, i) && q && *q != '\t' && j) {		F "am: Don't know how to make '%s'.\n", f);		exit(1);	}	W (0 < i) {		U(p);		if (t < M(p))			j = 1;		N(p, i);	}	if (j && q && *q == '\t') {		sleep(1);		W (*q++ == '\t') {			i = j = 1;			W (0 < S(q, "-+@")) {				if (*q == '@')										i = 0;				if (*q++ == '-')										j = 0;			}			if (i)				puts(q);			if (system(q) && j) {				F "am: Error making '%s'\n", f);				exit(1);			}			q += strlen(q) + 1;		}		c[k] = 0;	}}intmain(u, v)int u;char **v;{	FILE *f;	struct stat s;	size_t i, j, k;	char *m, *n, *p, *q, *r;	if (u < 2) {		F "usage: am <makefile> [target]\n");		R 2;	}	if (stat(*++v, &s) || !(f = fopen(*v, "r")))		R 3;	q = b = malloc(2*s.st_size);	if (!b)		R 4;	i = 1;	k = 0;	m = 0;	*t = *d = *c = "";	W ((r = fgets(l, BUFSIZ, f))) {		if (RULES <= i) {			F "am: Number of target-rules exceeds %d.\n", RULES);			R 1;		}		if (k) {			*q++ = ' ';			r += S(r, w);		} else {			if (t[i])				c[i++] = q;			if (m && putenv(m))				F "am: No more environment space.\n");			m = 0;			if (*l == '#' || *l == '\n')				C			p = q;		}		W (!(k = *r == '\\' && r[1] == '\n') && *r) {			if (*r == '$') {				if (r[1] == '(') {					n = r+2;					r += strcspn(r, ")");					*r++ = 0;					n = getenv(n);					if (n) 						q = strcpy(q, n) + strlen(n);					C				}				if (*r == r[1])					++r;			} 			if (*r == '=' && *l != '\t' && !m) {				*q = 0;				m = p;				j = 0;				q = N(m, j) + m;				*q++ = *r;				j = 1;				if (!N(r, j))					*q++ = 0;				C			}			if (*r == ':') {				t[i] = p;				*r = 0;				d[i] = q+1;			}			if (*r == '\n')				*r = 0;			*q++ = *r++;		}	}	fclose(f);	U(2 < u ? *++v : t[1]);	R 0;}