extra/gcc-uClibc/gcc-uClibc.c

   1
   2 /*
   3  * Copyright (C) 2000 Manuel Novoa III
   4  *
   5  * This is a crude wrapper to use uClibc with gcc.
   6  * It was originally written to work around ./configure for ext2fs-utils.
   7  * It certainly can be improved, but it works for me in the normal cases.
   8  *
   9  * April 7, 2001
  10  *
  11  * A bug was fixed in building the gcc command line when dynamic linking.
  12  * The functions dlopen, etc. now work.  At this time, you must make sure
  13  * the correct libdl.so is included however.  It is safest to, for example,
  14  * add /lib/libdl.so.1 if using ld-linux.so.1 rather than adding -ldl to the
  15  * command line.
  16  *
  17  * Note: This is only a problem if devel and target archs are the same.  To
  18  * avoid the problem, you can use a customized dynamic linker.
  19  *
  20  *
  21  * April 18, 2001
  22  *
  23  * The wrapper now works with either installed and uninstalled uClibc versions.
  24  * If you want to use the uninstalled header files and libs, either include
  25  * the string "build" in the invocation name such as
  26  *       'ln -s <ARCH>-uclibc-gcc <ARCH>-uclibc-gcc-build'
  27  * or include it in the environment variable setting of UCLIBC_GCC.
  28  * Note: This automatically enables the "rpath" behavior described below.
  29  *
  30  * The wrapper will now pass the location of the uClibc shared libs used to
  31  * the linker with the "-rpath" option if the invocation name includes the
  32  * string "rpath" or if the environment variable UCLIBC_GCC include it (as
  33  * with "build" above).  This is primarily intended to be used on devel
  34  * platforms of the same arch as the target.  A good place to use this feature
  35  * would be in the uClibc/test directory.
  36  *
  37  * The wrapper now displays the command line passed to gcc when '-v' is used.
  38  *
  39  * May 31, 2001
  40  *
  41  * "rpath" and "build" behavior are now decoupled.  You can of course get
  42  * the old "build" behavior by setting UCLIBC_GCC="rpath-build".  Order
  43  * isn't important here, as only the substrings are searched for.
  44  *
  45  * Added environment variable check for UCLIBC_GCC_DLOPT to let user specify
  46  * an alternative dynamic linker at runtime without using command line args.
  47  * Since this wouldn't commonly be used, I made it easy on myself.  You have
  48  * to match the option you would have passed to the gcc wrapper.  As an
  49  * example,
  50  *
  51  *   export UCLIBC_GCC_DLOPT="-Wl,--dynamic-linker,/lib/ld-alt-linker.so.3"
  52  *
  53  * This is really only useful if target arch == devel arch and DEVEL_PREFIX
  54  * isn't empty.  It involves a recompile, but you can at least test apps
  55  * on your devel system if combined with the "rpath" behavor if by using
  56  * LD_LIBRARY_PATH, etc.
  57  *
  58  * Also added check for "-Wl,--dynamic-linker" on the command line.  The
  59  * use default dynamic linker or the envirnment-specified dynamic linker
  60  * is disabled in that case.
  61  *
  62  * Added options --uclibc-use-build-dir and --uclibc-use-rpath so that those
  63  * behaviors can be invoked from the command line.
  64  *
  65  */
  66
  67 /*
  68  *
  69  * TODO:
  70  * Check/modify gcc-specific environment variables?
  71  */
  72
  73 #include <stdio.h>
  74 #include <stdlib.h>
  75 #include <string.h>
  76 #include <unistd.h>
  77
  78 #include "gcc-uClibc.h"
  79
  80 static char *rpath_link[] = {
  81         "-Wl,-rpath-link,"UCLIBC_DEVEL_PREFIX UCLIBC_ROOT_DIR"/lib",
  82         "-Wl,-rpath-link,"UCLIBC_BUILD_DIR"/lib"
  83 };
  84
  85 static char *rpath[] = {
  86         "-Wl,-rpath,"UCLIBC_DEVEL_PREFIX UCLIBC_ROOT_DIR"/lib",
  87         "-Wl,-rpath,"UCLIBC_BUILD_DIR"/lib"
  88 };
  89
  90 static char *uClibc_inc[] = {
  91         "-I"UCLIBC_DEVEL_PREFIX UCLIBC_ROOT_DIR"/usr/include/",
  92         "-I"UCLIBC_BUILD_DIR"/include/"
  93 };
  94
  95 static char *crt0_path[] = {
  96         UCLIBC_DEVEL_PREFIX UCLIBC_ROOT_DIR"/usr/lib/crt0.o",
  97         UCLIBC_BUILD_DIR"/lib/crt0.o"
  98 };
  99
 100 static char *lib_path[] = {
 101         "-L"UCLIBC_DEVEL_PREFIX UCLIBC_ROOT_DIR"/lib",
 102         "-L"UCLIBC_BUILD_DIR"/lib"
 103 };
 104
 105 static char *usr_lib_path = "-L"UCLIBC_DEVEL_PREFIX UCLIBC_ROOT_DIR"/usr/lib";
 106
 107 static char static_linking[] = "-static";
 108 static char nostdinc[] = "-nostdinc";
 109 static char nostartfiles[] = "-nostartfiles";
 110 static char nodefaultlibs[] = "-nodefaultlibs";
 111 static char nostdlib[] = "-nostdlib";
 112
 113 int main(int argc, char **argv)
 114 {
 115         int use_build_dir = 0, linking = 1, use_static_linking = 0;
 116         int use_stdinc = 1, use_start = 1, use_stdlib = 1;
 117         int source_count = 0, use_rpath = 0, verbose = 0;
 118         int i, j;
 119         char ** gcc_argv;
 120         char *dlstr;
 121         char *build_dlstr;
 122         char *ep;
 123
 124         build_dlstr = "-Wl,--dynamic-linker," BUILD_DYNAMIC_LINKER;
 125         dlstr = getenv("UCLIBC_GCC_DLOPT");
 126         if (!dlstr) {
 127                 dlstr = "-Wl,--dynamic-linker," DYNAMIC_LINKER;
 128         }
 129
 130         ep = getenv("UCLIBC_GCC");
 131         if (!ep) {
 132                 ep = "";
 133         }
 134
 135         if (strstr(ep,"build") != 0) {
 136                 use_build_dir = 1;
 137         }
 138
 139         if (strstr(ep,"rpath") != 0) {
 140                 use_rpath = 1;
 141         }
 142
 143         for ( i = 1 ; i < argc ; i++ ) {
 144                 if (argv[i][0] == '-') { /* option */
 145                         switch (argv[i][1]) {
 146                                 case 'c':               /* compile or assemble */
 147                                 case 'S':               /* generate assembler code */
 148                                 case 'E':               /* preprocess only */
 149                                 case 'r':               /* partial-link */
 150                                 case 'i':               /* partial-link */
 151                                 case 'M':       /* map file generation */
 152                                         if (argv[i][2] == 0) linking = 0;
 153                                         break;
 154                                 case 'v':               /* verbose */
 155                                         if (argv[i][2] == 0) verbose = 1;
 156                                         break;
 157                                 case 'n':
 158                                         if (strcmp(nostdinc,argv[i]) == 0) {
 159                                                 use_stdinc = 0;
 160                                         } else if (strcmp(nostartfiles,argv[i]) == 0) {
 161                                                 use_start = 0;
 162                                         } else if (strcmp(nodefaultlibs,argv[i]) == 0) {
 163                                                 use_stdlib = 0;
 164                                         } else if (strcmp(nostdlib,argv[i]) == 0) {
 165                                                 use_start = 0;
 166                                                 use_stdlib = 0;
 167                                         }
 168                                         break;
 169                                 case 's':
 170                                         if (strcmp(static_linking,argv[i]) == 0) {
 171                                                 use_static_linking = 1;
 172                                         }
 173                                         break;
 174                             case 'W':           /* -static could be passed directly to ld */
 175                                         if (strncmp("-Wl,",argv[i],4) == 0) {
 176                                                 if (strstr(argv[i],static_linking) != 0) {
 177                                                         use_static_linking = 1;
 178                                                 }
 179                                                 if (strstr(argv[i],"--dynamic-linker") != 0) {
 180                                                         dlstr = 0;
 181                                                 }
 182                                         }
 183                                         break;
 184                                 case '-':
 185                                         if (strcmp(static_linking,argv[i]+1) == 0) {
 186                                                 use_static_linking = 1;
 187                                         }
 188                                         break;
 189                         }
 190                 } else {                                /* assume it is an existing source file */
 191                         ++source_count;
 192                 }
 193         }
 194
 195 #if 1
 196         gcc_argv = __builtin_alloca(sizeof(char*) * (argc + 20));
 197 #else
 198         if (!(gcc_argv = malloc(sizeof(char) * (argc + 20)))) {
 199                 return EXIT_FAILURE;
 200         }
 201 #endif
 202
 203         i = 0;
 204         gcc_argv[i++] = GCC_BIN;
 205         for ( j = 1 ; j < argc ; j++ ) {
 206                 if (strcmp("--uclibc-use-build-dir",argv[j]) == 0) {
 207                         use_build_dir = 1;
 208                 } else if (strcmp("--uclibc-use-rpath",argv[j]) == 0) {
 209                         use_rpath = 1;
 210                 } else {
 211                         gcc_argv[i++] = argv[j];
 212                 }
 213         }
 214         if (use_stdinc) {
 215                 gcc_argv[i++] = nostdinc;
 216                 gcc_argv[i++] = uClibc_inc[use_build_dir];
 217                 gcc_argv[i++] = GCC_INCDIR;
 218         }
 219         if (linking && source_count) {
 220                 if (!use_static_linking) {
 221                         if (dlstr && use_build_dir) {
 222                                 gcc_argv[i++] = build_dlstr;
 223                         } else if (dlstr) {
 224                                 gcc_argv[i++] = dlstr;
 225                         }
 226                         if (use_rpath) {
 227                                 gcc_argv[i++] = rpath[use_build_dir];
 228                         }
 229                 }
 230                 gcc_argv[i++] = rpath_link[use_build_dir]; /* just to be safe */
 231                 gcc_argv[i++] = lib_path[use_build_dir];
 232                 if (!use_build_dir) {
 233                         gcc_argv[i++] = usr_lib_path;
 234                 }
 235                 if (use_start) {
 236                         gcc_argv[i++] = crt0_path[use_build_dir];
 237                 }
 238                 if (use_stdlib) {
 239                         gcc_argv[i++] = nostdlib;
 240                         gcc_argv[i++] = "-lc";
 241                         gcc_argv[i++] = GCC_LIB;
 242                 }
 243         }
 244         gcc_argv[i++] = NULL;
 245
 246         if (verbose) {
 247                 printf("Invoked as %s\n", argv[0]);
 248                 for ( j = 0 ; gcc_argv[j] ; j++ ) {
 249                         printf("arg[%2i] = %s\n", j, gcc_argv[j]);
 250                 }
 251         }
 252
 253         return execvp(GCC_BIN, gcc_argv);
 254 }