/*
 * The assembler driver that lives in /bin/as and runs the assembler for the
 * "-arch <arch_flag>" (if given) in /usr/libexec/gcc/darwin/<arch_flag>/as or
 * in /usr/local/libexec/gcc/darwin/<arch_flag>/as.  Or runs the assembler for
 * the host architecture as returned by get_arch_from_host().  The driver only
 * checks to make sure their are not multiple arch_flags and then passes all
 * flags to the assembler it will run.
 */
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "libc.h"
#include <sys/file.h>
#include <mach/mach.h>
#include "stuff/arch.h"
#include "stuff/errors.h"
#include "stuff/execute.h"
#include "stuff/allocate.h"

/* used by error calls (exported) */
char *progname = NULL;

int
main(
int argc,
char **argv,
char **envp)
{
    const char *LIB =
#if defined(__OPENSTEP__) || defined(__HERA__) || \
    defined(__GONZO_BUNSEN_BEAKER__) || defined(__KODIAK__)
		    "/usr/libexec/";
#else
		    "/usr/libexec/gcc/darwin/";
#endif
    const char *LOCALLIB =
#if defined(__OPENSTEP__) || defined(__HERA__) || \
    defined(__GONZO_BUNSEN_BEAKER__) || defined(__KODIAK__)
		    "/usr/local/libexec/";
#else
		    "/usr/local/libexec/gcc/darwin/";
#endif
    const char *AS = "/as";

    int i;
    unsigned long count, verbose;
    char *p, c, *arch_name, *as, *as_local;
    struct arch_flag arch_flag;
    const struct arch_flag *arch_flags, *family_arch_flag;

	progname = argv[0];
	arch_name = NULL;
	verbose = 0;
	/*
	 * Process the assembler flags exactly like the assembler would (except
	 * let the assembler complain about multiple flags, bad combinations of
	 * flags, unknown single letter flags and the like).  The main thing
	 * here is to parse out the "-arch <arch_flag>" and to do so the
	 * multiple argument and multiple character flags need to be known how
	 * to be stepped over correctly.
	 */
	for(i = 1; i < argc; i++){
	    /*
	     * The assembler flags start with '-' except that "--" is recognized
	     * as assemble from stdin and that flag "--" is not allowed to be
	     * grouped with other flags (so "-a-" is not the same as "-a --").
	     */
	    if(argv[i][0] == '-' &&
	       !(argv[i][1] == '-' && argv[i][2] == '0')){
		/*
		 * the assembler allows single letter flags to be grouped
		 * together so "-abc" is the same as "-a -b -c".  So that
		 * logic must be followed here.
		 */
		for(p = &(argv[i][1]); (c = *p); p++){
		    /*
		     * The assembler simply ignores the high bit of flag
		     * characters and not treat them as different characters
		     * as they are (but the argument following the flag
		     * character is not treated this way).  So it's done
		     * here as well to match it.
		     */
		    c &= 0x7F;
		    switch(c){
		    /*
		     * Flags that take a single argument.  The argument is the
		     * rest of the current argument if there is any or the it is
		     * the next argument.  Again errors like missing arguments
		     * are not handled here but left to the assembler.
		     */
		    case 'o':	/* -o name */
		    case 'I':	/* -I directory */
		    case 'm':	/* -mc68000, -mc68010 and mc68020 */
		    case 'N':	/* -NEXTSTEP-deployment-target */
			if(p[1] == '\0')
			    i++;
			break;

		    case 'a':
			if(strcmp(p, "arch") == 0){
			    if(i + 1 >= argc)
				fatal("missing argument to %s option", argv[i]);
			    if(arch_name != NULL)
				fatal("more than one %s option (not allowed, "
				      "use cc(1) instead)", argv[i]);
			    arch_name = argv[i+1];
			    break;
			}
			/* fall through for non "-arch" */
		    case 'f':
		    case 'k':
		    case 'g':
		    case 'v':
		    case 'W':
		    case 'L':
		    case 'l':
		    default:
			/* just recognize it, do nothing */
			break;
		    case 'V':
			verbose = 1;
			break;
		    }
		}
	    }
	}

	/*
	 * Construct the name of the assembler to run from the given -arch
	 * <arch_flag> or if none then from the value returned from
	 * get_arch_from_host().
	 */
	if(arch_name == NULL){
	    if(get_arch_from_host(&arch_flag, NULL))
		arch_name = arch_flag.name;
	    else
		fatal("known host architecture (can't determine which assembler"
		      " to run)");
	}
	else{
	    /*
	     * Convert a possible machine specific architecture name to a
	     * family name to base the name of the assembler to run.
	     */
	    if(get_arch_from_flag(arch_name, &arch_flag) != 0){
		family_arch_flag =
			get_arch_family_from_cputype(arch_flag.cputype);
		if(family_arch_flag != NULL)
		    arch_name = (char *)(family_arch_flag->name);
	    }

	}
	as = makestr(LIB, arch_name, AS, NULL);

	/*
	 * If this assembler exist try to run it else print an error message.
	 */
	if(access(as, F_OK) == 0){
	    argv[0] = as;
	    if(execute(argv, verbose))
		exit(0);
	    else
		exit(1);
	}
	as_local = makestr(LOCALLIB, arch_name, AS, NULL);
	if(access(as_local, F_OK) == 0){
	    argv[0] = as_local;
	    if(execute(argv, verbose))
		exit(0);
	    else
		exit(1);
	}
	else{
	    printf("%s: assembler (%s or %s) for architecture %s not "
		   "installed\n", progname, as, as_local, arch_name);
	    arch_flags = get_arch_flags();
	    count = 0;
	    for(i = 0; arch_flags[i].name != NULL; i++){
		as = makestr(LIB, arch_flags[i].name, AS, NULL);
		if(access(as, F_OK) == 0){
		    if(count == 0)
			printf("Installed assemblers are:\n");
		    printf("%s for architecture %s\n", as, arch_flags[i].name);
		    count++;
		}
		else{
		    as_local = makestr(LOCALLIB, arch_flags[i].name, AS, NULL);
		    if(access(as_local, F_OK) == 0){
			if(count == 0)
			    printf("Installed assemblers are:\n");
			printf("%s for architecture %s\n", as_local,
			       arch_flags[i].name);
			count++;
		    }
		}
	    }
	    if(count == 0)
		printf("%s: no assemblers installed\n", progname);
	    exit(1);
	}
	return(0);
}
