main.c

unix环境下实现的cmm语言编译器

#include "cmm.h"
#include <unistd.h>
#include <fcntl.h>

Interface *IR = &x86IR;

struct arg{
	char *name;
	int	 generated;
};
static char	*infile, *outfile;
static int	fs, fc, fo;	/*-S选项，-c选项, -o选项*/
static int	doarg(int argc, char *argv[]);
static char	*genname(char *path, char *suffix);
static char *get_suffix(char *path);

int main(int argc, char *argv[]) 
{
	int i,j;
	static struct arg *asmset,*objset;

	fs = fc = fo = 0;
	i = doarg(argc, argv);
	asmset = newarray(sizeof (struct arg ), argc - i + 1, PERM);
	objset = newarray(sizeof (struct arg ), argc - i + 1, PERM);
	for (j = 0; j < argc - i + 1; j++) {
		asmset[j].name = objset[j].name = NULL;
		asmset[j].generated = objset[j].generated = 0;
	}
	(*IR->progbeg)();
	for (j = 0;i < argc; i++, j++) {
		char *ps;
		infile = argv[i];
		ps = get_suffix(argv[i]);
		if (!strcmp(ps, ".asm") || !strcmp(ps, ".s")) {
			asmset[j].name = argv[i];
			continue;
		}
		else if (!strcmp(ps, ".o")) {
			objset[j].name = argv[i];
			continue;
		}
		if (fo && fs)
			asmset[j].name  = outfile;
		else if (fs || (fc && !fo)) {
			asmset[j].name = genname(infile, ".asm");
			asmset[j].generated = 1;
		}
		else {
			asmset[j].name  = tempnam(".",NULL);
			asmset[j].generated = 1;
		}

		if (infile != NULL)
			if ((infd = open(infile, 0)) < 0) {
				fprint(2, "%s: can't read `%s'\n",
					argv[0], infile);
				exit(1);
			}
		if (asmset[j].name != NULL)
			if ((outfd = creat(asmset[j].name, 0666)) < 0) {
				fprint(2, "%s: can't write `%s'\n",
					argv[0], asmset[j].name);
				exit(1);
			}
		inputInit();
		outputInit();
		init_sym();	
		t = gettoken();
		program();
		finalize();
		outflush();
		close(infd);
		close(outfd);
	}

	if (!errcnt) {
		int s;
		if (fs)
			goto finish;
		if (fc && fo) {
			s = system(stringf("nasm -f elf %s -o %s", asmset[0].name,outfile));
			if (asmset[0].generated)
				unlink(asmset[0].name);
			if (s)
				exit(1);
			goto finish;
		}
		{char *objstr;
			for (i = 0; asmset[i].name || objset[i].name; i++) {
				if (asmset[i].name) {
					objset[i].name = genname(asmset[i].name, ".o");
					objset[i].generated = 1;
					s = system(stringf("nasm -f elf %s -o %s",
							asmset[i].name, objset[i].name));
					if (asmset[i].generated)
						unlink(asmset[i].name);
					if (s)
						exit(1);
				}
			}
			if (fc)
				goto finish;
			if (!fo) {
				outfile = "a.out";
				if (i >= 2)
					i = 1;
			}
			objstr = allocate(_POSIX_ARG_MAX, PERM);
			*objstr = '\0';
			for (j = 0; j < i; j++) {
				if (strlen(objstr) >= _POSIX_ARG_MAX)
					break;
				strcat(objstr, stringf("%s ",objset[j].name));
			}
			s = system(stringf("ld -o %s -dynamic-linker \
						/lib/ld-linux.so.2 \
						/usr/lib/crt1.o \
						/usr/lib/crti.o \
						/usr/lib/crtn.o %s \
						-L/usr/lib -lc -lm",
						outfile, objstr));
			for (j = 0; objset[j].name; j++)
				if (objset[j].generated)
					unlink(objset[j].name);
			if (s)
				exit(1);
		}
	}
finish:
	close(errfd);
	deallocate(PERM);
	dispose();
	return errcnt > 0;
}

#define  OPTSTR "Sco:"
static int doarg(int argc, char *argv[])
{
	int	c;
	
	opterr = 0;
	while ((c = getopt(argc, argv, OPTSTR)) != EOF) {
		switch (c) {
		case 'S':
			fs = 1;
			break;
		case 'c':
			fc = 1;
			break;
		case 'o':
			outfile = optarg;
			fo = 1;
			break;
		case '?':
			error("unrecognized option: -%c", optopt);
			fprint(2, "usage: scc [-S] [-c] [-o outfile] inputfile");
			exit(1);
		}
	}
	if (optind >= argc) {
		fprint(2, "usage: scc [-S] [-c] [-o outfile] inputfile\n");
		exit(1);
	}
	if ((fs || fc) && fo && optind < argc - 1) {
		fprint(2, "当有多个文件时不能在已指定 -c 或 -S 的情况下指定 -o\n");
		exit(1);
	}
	if (fs)
		fc = 0;
	return optind;
}

/*genname:将后缀suffix替换原来的后缀生成输出文件名*/
static char *genname(char *path,char *suffix)
{
	int i,j,k;
	char *p;
	for (i=j=k=0; path[i]; i++)
		if ('/' == path[i])
			j = i;
		else if ('.' == path[i])
			k = i;
	if (j) j++;		/*path为当前目录下的文件名*/
	if (!k) k = i;	/*path中没有后缀*/
	for (i = 0; suffix[i]; i++)
		;
	p = allocate(i + k - j + 1, PERM);
	for (i = 0;j < k; j++,i++)
		p[i] = path[j];
	while ((p[i++] = *suffix++) != '\0')
		;
	return p;
}

/*get_suffix:返回文件名中的后缀*/
static char *get_suffix(char *path)
{
	int i,j;
	char *p;

	for (i=j=0; path[i]; i++)
      if ('.' == path[i])
		j = i;
	if (!j) j = i;
	p = allocate(i - j + 1, PERM);
	i = 0;
	while ((p[i++] = path[j++]) != '\0')
		;
	return p;
}