uclibc-ng/extra/gcc-uClibc/gcc-uClibc.c

/* vi: set sw=4 ts=4: */
/*
 * Copyright (C) 2000 Manuel Novoa III
 * Copyright (C) 2002 Erik Andersen
 *
 * This is a crude wrapper to use uClibc with gcc.
 * It was originally written to work around ./configure for ext2fs-utils.
 * It certainly can be improved, but it works for me in the normal cases.
 *
 * April 7, 2001
 *
 * A bug was fixed in building the gcc command line when dynamic linking.
 * The functions dlopen, etc. now work.  At this time, you must make sure
 * the correct libdl.so is included however.  It is safest to, for example,
 * add /lib/libdl.so.1 if using ld-linux.so.1 rather than adding -ldl to the
 * command line.
 *
 * Note: This is only a problem if devel and target archs are the same.  To
 * avoid the problem, you can use a customized dynamic linker.
 *
 *
 * April 18, 2001
 *
 * The wrapper now works with either installed and uninstalled uClibc versions.
 * If you want to use the uninstalled header files and libs, either include
 * the string "build" in the invocation name such as
 *       'ln -s <ARCH>-uclibc-gcc <ARCH>-uclibc-gcc-build'
 * or include it in the environment variable setting of UCLIBC_ENV.
 * Note: This automatically enables the "rpath" behavior described below.
 *
 * The wrapper will now pass the location of the uClibc shared libs used to
 * the linker with the "-rpath" option if the invocation name includes the
 * string "rpath" or if the environment variable UCLIBC_ENV include it (as
 * with "build" above).  This is primarily intended to be used on devel
 * platforms of the same arch as the target.  A good place to use this feature
 * would be in the uClibc/test directory.
 *
 * The wrapper now displays the command line passed to gcc when '-v' is used.
 *
 * May 31, 2001
 *
 * "rpath" and "build" behavior are now decoupled.  You can of course get
 * the old "build" behavior by setting UCLIBC_ENV="rpath-build".  Order
 * isn't important here, as only the substrings are searched for.
 *
 * Added environment variable check for UCLIBC_GCC_DLOPT to let user specify
 * an alternative dynamic linker at runtime without using command line args.
 * Since this wouldn't commonly be used, I made it easy on myself.  You have
 * to match the option you would have passed to the gcc wrapper.  As an
 * example,
 *
 *   export UCLIBC_GCC_DLOPT="-Wl,--dynamic-linker,/lib/ld-alt-linker.so.3"
 *
 * This is really only useful if target arch == devel arch and DEVEL_PREFIX
 * isn't empty.  It involves a recompile, but you can at least test apps
 * on your devel system if combined with the "rpath" behavor if by using
 * LD_LIBRARY_PATH, etc.
 *
 * Also added check for "-Wl,--dynamic-linker" on the command line.  The
 * use default dynamic linker or the envirnment-specified dynamic linker
 * is disabled in that case.
 *
 * Added options --uclibc-use-build-dir and --uclibc-use-rpath so that those
 * behaviors can be invoked from the command line.
 *
 */

/*
 *
 * TODO:
 * Check/modify gcc-specific environment variables?
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include "gcc-uClibc.h"

static char *our_usr_lib_path = "-L"UCLIBC_DEVEL_PREFIX"/lib";

static char static_linking[] = "-static";
static char nostdinc[] = "-nostdinc";
static char nostartfiles[] = "-nostartfiles";
static char nodefaultlibs[] = "-nodefaultlibs";
static char nostdlib[] = "-nostdlib";
#ifdef __UCLIBC_CTOR_DTOR__
static char nostdinc_plus[] = "-nostdinc++";
#endif

/* Include a local implementation of basename, since this
 * uses the host system's C lib, and CYGWIN apparently
 * doesn't provide an implementation of basename(). */
char *basename(const char *path)
{
    register const char *s;
    register const char *p;
    p = s = path;
    while (*s) {
	if (*s++ == '/') {
	    p = s;
	}
    }
    return (char *) p;
}

char *dirname(char *path)
{
    static const char null_or_empty_or_noslash[] = ".";
    register char *s;
    register char *last;
    char *first;

    last = s = path;

    if (s != NULL) {

LOOP:
	while (*s && (*s != '/')) ++s;
	first = s;
	while (*s == '/') ++s;
	if (*s) {
	    last = first;
	    goto LOOP;
	}

	if (last == path) {
	    if (*last != '/') {
		goto DOT;
	    }
	    if ((*++last == '/') && (last[1] == 0)) {
		++last;
	    }
	}
	*last = 0;
	return path;
    }
DOT:
    return (char *) null_or_empty_or_noslash;
}


extern void *xmalloc(size_t size)
{
    void *ptr = malloc(size);

    if (!ptr) {
	fprintf(stderr, "memory exhausted");
	exit(EXIT_FAILURE);
    }
    return ptr;
}

void xstrcat(char **string, ...)
{
    const char *c;
    va_list p; 
    /* Don't bother to calculate how big exerything 
     * will be, just be careful to not overflow...  */
    va_start(p, string);
    *string = xmalloc(BUFSIZ);
    **string = '\0';
    while(1) {
	if (!(c = va_arg(p, const char *)))
	    break;
	strcat(*string, c); 
    }
    va_end(p);
}

int main(int argc, char **argv)
{
    int use_build_dir = 0, linking = 1, use_static_linking = 0;
    int use_stdinc = 1, use_start = 1, use_stdlib = 1, use_pic = 0;
    int source_count = 0, use_rpath = 0, verbose = 0;
    int i, j, k, l, m, n;
    char ** gcc_argv;
    char ** gcc_argument;
    char ** libraries;
    char ** libpath;
    char *dlstr;
    char *incstr;
    char *devprefix;
    char *builddir;
    char *libstr;
    char *build_dlstr = 0;
    char *cc;
    char *ep;
    char *rpath_link[2];
    char *rpath[2];
    char *uClibc_inc[2];
    char *our_lib_path[2];
    char *crt0_path[2];
    char *crtbegin_path[2];
    char *crtend_path[2];
    const char *application_name;
#ifdef __UCLIBC_CTOR_DTOR__
    char *crti_path[2];
    char *crtn_path[2];
    int len;
    int ctor_dtor = 1, cplusplus = 0, use_nostdinc_plus = 0;
    char *GPLUSPLUS_BIN = NULL;
#endif
#ifdef __UCLIBC_PROFILING__
    int profile = 0;
    char *gcrt1_path[2];
#endif

    cc     = getenv("UCLIBC_CC");
    if (!cc) {
	cc = GCC_BIN;
    }

    application_name = basename(argv[0]);
    if (application_name[0] == '-')
	application_name++;

#ifdef __UCLIBC_CTOR_DTOR__
    /* We must use strstr since g++ might be named like a
     * cross compiler (i.e. arm-linux-g++).   We must also
     * search carefully, in case we are searching something 
     * like /opt/c++/gcc-3.1/bin/arm-linux-g++ or some similar 
     * perversion...  */
    len = strlen(application_name);
    if ((strcmp(application_name+len-3, "g++")==0) ||
	    (strcmp(application_name+len-3, "c++")==0)) {
	len = strlen(cc);
	if (strcmp(cc+len-3, "gcc")==0) {
	    GPLUSPLUS_BIN = strdup(cc);
	    GPLUSPLUS_BIN[len-1]='+';
	    GPLUSPLUS_BIN[len-2]='+';
	}
	cplusplus = 1;
	use_nostdinc_plus = 1;
    }
#endif

    devprefix = getenv("UCLIBC_DEVEL_PREFIX");
    if (!devprefix) {
	devprefix = UCLIBC_DEVEL_PREFIX;
    }

    builddir = getenv("UCLIBC_BUILD_DIR");
    if (!builddir) {
	builddir = UCLIBC_BUILD_DIR;
    }

    incstr = getenv("UCLIBC_GCC_INC");
    libstr = getenv("UCLIBC_GCC_LIB");

    ep     = getenv("UCLIBC_ENV");
    if (!ep) {
	ep = "";
    }

    if (strstr(ep,"build") != 0) {
	use_build_dir = 1;
    }

    if (strstr(ep,"rpath") != 0) {
	use_rpath = 1;
    }


    xstrcat(&(rpath_link[0]), "-Wl,-rpath-link,", devprefix, "/lib", NULL);
    xstrcat(&(rpath_link[1]), "-Wl,-rpath-link,", builddir, "/lib", NULL);

    xstrcat(&(rpath[0]), "-Wl,-rpath,", devprefix, "/lib", NULL);
    xstrcat(&(rpath[1]), "-Wl,-rpath,", builddir, "/lib", NULL);

    xstrcat(&(uClibc_inc[0]), devprefix, "/include/", NULL);
    xstrcat(&(uClibc_inc[1]), builddir, "/include/", NULL);

#ifdef __UCLIBC_CTOR_DTOR__
    xstrcat(&(crt0_path[0]), devprefix, "/lib/crt1.o", NULL);
    xstrcat(&(crt0_path[1]), builddir, "/lib/crt1.o", NULL);
    xstrcat(&(crti_path[0]), devprefix, "/lib/crti.o", NULL);
    xstrcat(&(crti_path[1]), builddir, "/lib/crti.o", NULL);
    xstrcat(&(crtn_path[0]), devprefix, "/lib/crtn.o", NULL);
    xstrcat(&(crtn_path[1]), builddir, "/lib/crtn.o", NULL);
#else
    xstrcat(&(crt0_path[0]), devprefix, "/lib/crt0.o", NULL);
    xstrcat(&(crt0_path[1]), builddir, "/lib/crt0.o", NULL);
#endif
#ifdef __UCLIBC_PROFILING__
    xstrcat(&(gcrt1_path[0]), devprefix, "/lib/gcrt1.o", NULL);
    xstrcat(&(gcrt1_path[1]), builddir, "/lib/gcrt1.o", NULL);
#endif

    xstrcat(&(our_lib_path[0]), "-L", devprefix, "/lib", NULL);
    xstrcat(&(our_lib_path[1]), "-L", builddir, "/lib", NULL);

#ifdef __UCLIBC_HAS_SHARED__
    build_dlstr = "-Wl,--dynamic-linker," BUILD_DYNAMIC_LINKER;
    dlstr = getenv("UCLIBC_GCC_DLOPT");
    if (!dlstr) {
	dlstr = "-Wl,--dynamic-linker," DYNAMIC_LINKER;
    }
#endif

    m = 0;
    libraries = __builtin_alloca(sizeof(char*) * (argc));
    libraries[m] = '\0';

    n = 0;
    libpath = __builtin_alloca(sizeof(char*) * (argc));
    libpath[n] = '\0';

    for ( i = 1 ; i < argc ; i++ ) {
	if (argv[i][0] == '-') { /* option */
	    switch (argv[i][1]) {
		case 'c':		/* compile or assemble */
		case 'S':		/* generate assembler code */
		case 'E':		/* preprocess only */
		case 'M':	    /* generate dependencies */
		    linking = 0;
		    break;
		case 'L': 		/* library */
		    libpath[n++] = argv[i];
		    libpath[n] = '\0';
		    if (argv[i][2] == 0) {
			argv[i] = '\0';
			libpath[n++] = argv[++i];
			libpath[n] = '\0';
		    }
		    argv[i] = '\0';
		    break;
		case 'l': 		/* library */
		    libraries[m++] = argv[i];
		    libraries[m] = '\0';
		    argv[i] = '\0';
		    break;
		case 'v':		/* verbose */
		    if (argv[i][2] == 0) verbose = 1;
		    printf("Invoked as %s\n", argv[0]);
		    break;
		case 'n':
		    if (strcmp(nostdinc,argv[i]) == 0) {
			use_stdinc = 0;
		    } else if (strcmp(nostartfiles,argv[i]) == 0) {
#ifdef __UCLIBC_CTOR_DTOR__
			ctor_dtor = 0;
#endif
			use_start = 0;
		    } else if (strcmp(nodefaultlibs,argv[i]) == 0) {
			use_stdlib = 0;
			argv[i] = '\0';
		    } else if (strcmp(nostdlib,argv[i]) == 0) {
#ifdef __UCLIBC_CTOR_DTOR__
			ctor_dtor = 0;
#endif
			use_start = 0;
			use_stdlib = 0;
		    } 
#ifdef __UCLIBC_CTOR_DTOR__
		    else if (strcmp(nostdinc_plus,argv[i]) == 0) {
			if (cplusplus==1) {
			    use_nostdinc_plus = 0;
			}
		    }
#endif
		    break;
		case 's':
		    if (strstr(argv[i],static_linking) != NULL) {
			use_static_linking = 1;
		    }
		    if (strcmp("-shared",argv[i]) == 0) {
			use_start = 0;
			use_pic = 1;
		    }
		    break;
		case 'W':		/* -static could be passed directly to ld */
		    if (strncmp("-Wl,",argv[i],4) == 0) {
			if (strstr(argv[i],static_linking) != 0) {
			    use_static_linking = 1;
			}
			if (strstr(argv[i],"--dynamic-linker") != 0) {
			    dlstr = 0;
			}
		    }
		    break;
#ifdef __UCLIBC_PROFILING__
		case 'p':
		    if (strcmp("-pg",argv[i]) == 0) {
			profile = 1;
		    }
		    break;
#endif
		case 'f':
		    /* Check if we are doing PIC */
		    if (strcmp("-fPIC",argv[i]) == 0) {
			use_pic = 1;
		    } else if (strcmp("-fpic",argv[i]) == 0) {
			use_pic = 1;
		    } 
#ifdef __UCLIBC_PROFILING__
		    else if (strcmp("-fprofile-arcs",argv[i]) == 0) {
			profile = 1;
		    }
#endif
		    break;

		case '-':
		    if (strstr(argv[i]+1,static_linking) != NULL) {
			use_static_linking = 1;
			argv[i]='\0';
		    } else if (strcmp("--uclibc-use-build-dir",argv[i]) == 0) {
			use_build_dir = 1;
			argv[i]='\0';
		    } else if (strcmp("--uclibc-use-rpath",argv[i]) == 0) {
			use_rpath = 1;
			argv[i]='\0';
		    }
#ifdef __UCLIBC_CTOR_DTOR__
		    else if (strcmp("--uclibc-no-ctors",argv[i]) == 0) {
			ctor_dtor = 0;
			argv[i]='\0';
		    }
#endif
		    break;
	    }
	} else {				/* assume it is an existing source file */
	    ++source_count;
	}
    }

    gcc_argv = __builtin_alloca(sizeof(char*) * (argc + 64));
    gcc_argument = __builtin_alloca(sizeof(char*) * (argc + 20));

    i = 0; k = 0;
#ifdef __UCLIBC_CTOR_DTOR__
    if (ctor_dtor) {
	struct stat statbuf;
	if (stat(LIBGCC_DIR, &statbuf)!=0 || 
		!S_ISDIR(statbuf.st_mode))
	{
	    /* Bummer, gcc has moved things on us... */
	    int status, gcc_pipe[2];
	    pid_t pid, wpid;

	    pipe(gcc_pipe);
	    if (!(pid = fork())) {
		char *argv[4];
		close(gcc_pipe[0]);
		close(1);
		close(2);
		dup2(gcc_pipe[1], 1);
		dup2(gcc_pipe[1], 2);
		argv[0] = cc; 
		argv[2] = "-print-libgcc-file-name";
		argv[3] = NULL;
		execvp(argv[0], argv);
		close(gcc_pipe[1]);
		_exit(-1);
	    }
	    wpid=0;
	    while (wpid != pid) {
		wpid = wait(&status);
	    }
	    close(gcc_pipe[1]);
	    if (WIFEXITED(status)) {
		char buf[1024], *dir;
		status = read(gcc_pipe[0], buf, sizeof(buf));
		if (status < 0) {
		    goto crash_n_burn;
		}
		dir = dirname(buf);
		xstrcat(&(crtbegin_path[0]), dir, "crtbegin.o", NULL);
		xstrcat(&(crtbegin_path[1]), dir, "crtbeginS.o", NULL);
		xstrcat(&(crtend_path[0]), dir, "crtend.o", NULL);
		xstrcat(&(crtend_path[1]), dir, "crtendS.o", NULL);
	    } else {
crash_n_burn:
		fprintf(stderr, "Unable to locale crtbegin.o provided by gcc");
		exit(EXIT_FAILURE);
	    }
	    close(gcc_pipe[0]);

	} else {
	    xstrcat(&(crtbegin_path[0]), LIBGCC_DIR, "crtbegin.o", NULL);
	    xstrcat(&(crtbegin_path[1]), LIBGCC_DIR, "crtbeginS.o", NULL);
	    xstrcat(&(crtend_path[0]), LIBGCC_DIR, "crtend.o", NULL);
	    xstrcat(&(crtend_path[1]), LIBGCC_DIR, "crtendS.o", NULL);
	}
    }

    if (cplusplus && GPLUSPLUS_BIN)
	gcc_argv[i++] = GPLUSPLUS_BIN;
    else
#endif
	gcc_argv[i++] = cc;

    for ( j = 1 ; j < argc ; j++ ) {
	if (argv[j]=='\0') {
	    continue;
	} else {
	    gcc_argument[k++] = argv[j];
	    gcc_argument[k] = '\0';
	}
    }

    if (linking && source_count) {
#if defined __HAVE_ELF__ && ! defined __UCLIBC_HAS_MMU__
	gcc_argv[i++] = "-Wl,-elf2flt";
#endif
	gcc_argv[i++] = nostdlib;
	if (use_static_linking) {
	    gcc_argv[i++] = static_linking;
	}
	if (!use_static_linking) {
	    if (dlstr && use_build_dir) {
		gcc_argv[i++] = build_dlstr;
	    } else if (dlstr) {
		gcc_argv[i++] = dlstr;
	    }
	    if (use_rpath) {
		gcc_argv[i++] = rpath[use_build_dir];
	    }
	}
	for ( l = 0 ; l < n ; l++ ) {
	    if (libpath[l]) gcc_argv[i++] = libpath[l];
	}
	gcc_argv[i++] = rpath_link[use_build_dir]; /* just to be safe */
	if( libstr )
	    gcc_argv[i++] = libstr;
	gcc_argv[i++] = our_lib_path[use_build_dir];
	if (!use_build_dir) {
	    gcc_argv[i++] = our_usr_lib_path;
	}
    }
    if (use_stdinc && source_count) {
	gcc_argv[i++] = nostdinc;
#ifdef __UCLIBC_CTOR_DTOR__
	if (cplusplus) {
	    char *cppinc;
	    if (use_nostdinc_plus) {
		gcc_argv[i++] = nostdinc_plus;
	    }
	    xstrcat(&cppinc, uClibc_inc[use_build_dir], "g++/", NULL);
	    gcc_argv[i++] = "-isystem";
	    gcc_argv[i++] = cppinc;
	    xstrcat(&cppinc, uClibc_inc[use_build_dir], "g++-v3/", NULL);
	    gcc_argv[i++] = "-isystem";
	    gcc_argv[i++] = cppinc;
	}
#endif
	gcc_argv[i++] = "-isystem";
	gcc_argv[i++] = uClibc_inc[use_build_dir];
	gcc_argv[i++] = "-iwithprefix";
	gcc_argv[i++] = "include";
	if( incstr )
	    gcc_argv[i++] = incstr;
    }

    if (linking && source_count) {

#ifdef __UCLIBC_PROFILING__
	if (profile) {
	    gcc_argv[i++] = gcrt1_path[use_build_dir];
	}
#endif
#ifdef __UCLIBC_CTOR_DTOR__
	if (ctor_dtor) {
	    gcc_argv[i++] = crti_path[use_build_dir];
	    if (use_pic) {
		gcc_argv[i++] = crtbegin_path[1];
	    } else {
		gcc_argv[i++] = crtbegin_path[0];
	    }
	}
#endif
	if (use_start) {
#ifdef __UCLIBC_PROFILING__
	    if (!profile)
#endif
	    {
		gcc_argv[i++] = crt0_path[use_build_dir];
	    }
	}
	for ( l = 0 ; l < k ; l++ ) {
	    if (gcc_argument[l]) gcc_argv[i++] = gcc_argument[l];
	}
	if (use_stdlib) {
	    //gcc_argv[i++] = "-Wl,--start-group";
	    gcc_argv[i++] = "-lgcc";
	}
	for ( l = 0 ; l < m ; l++ ) {
	    if (libraries[l]) gcc_argv[i++] = libraries[l];
	}
	if (use_stdlib) {
#ifdef __UCLIBC_CTOR_DTOR__
	    if (cplusplus) {
		gcc_argv[ i++ ] = "-lstdc++";
		gcc_argv[ i++ ] = "-lm";
	    }
#endif
	    gcc_argv[i++] = "-lc";
	    gcc_argv[i++] = "-lgcc";
	    //gcc_argv[i++] = "-Wl,--end-group";
	}
#ifdef __UCLIBC_CTOR_DTOR__
	if (ctor_dtor) {
	    if (use_pic) {
		gcc_argv[i++] = crtend_path[1];
	    } else {
		gcc_argv[i++] = crtend_path[0];
	    }

	    gcc_argv[i++] = crtn_path[use_build_dir];
	}
#endif
    } else {
	for ( l = 0 ; l < k ; l++ ) {
	    if (gcc_argument[l]) gcc_argv[i++] = gcc_argument[l];
	}
    }
    gcc_argv[i++] = NULL;

    if (verbose) {
	for ( j = 0 ; gcc_argv[j] ; j++ ) {
	    printf("arg[%2i] = %s\n", j, gcc_argv[j]);
	}
	fflush(stdout);
    }
    //no need to free memory from xstrcat because we never return... 
#ifdef __UCLIBC_CTOR_DTOR__
    if (cplusplus && GPLUSPLUS_BIN)
	return execvp(GPLUSPLUS_BIN, gcc_argv);
    else
#endif
	return execvp(cc, gcc_argv);
}