When we converted ld-elf2flt from the shell script to C, one small nuance

was missed: argv[0] contains the full path only when invoked with the full
path.  This is not the same behavior for shell scripts as $0 is always the
full path to the script in question.  Most of the time this isn't an issue
as gcc will invoke all of its tools (like the linker) with a full relative
path to itself.  However, if we attempt to invoke the linker directly, we
can see misbehavior such as:
	bfin-uclinux-ld.real: cannot open linker script file ./../lib/elf2flt.ld:
		No such file or directory

So, to fix this, we lean on more libiberty functions.  Specifically, the
make_relative_prefix() function.  This function locates a full argv[0] by
scanning $PATH to see where it was invoked.  This might sound a little
dodgy, but this is fundamental to how gcc and binutils implement support
for their runtime relocation, so it can't break ld-elf2flt without first
breaking every one else ;).

In the fall out of this fix, we can cull a bunch of local code that does
custom path parsing.  So not only do we get to fix an annoying bug, we get
to shrink code in the process.

Signed-off-by: Steve Kilbane <steve@whitecrow.demon.co.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/ld-elf2flt.c b/ld-elf2flt.c
index 707e9e10fef4c195e294ebe99c4f828f3b87c4b4..e4cb0736f4ad6898a1a3f79af222d60b11877af0 100644 (file)
--- a/ld-elf2flt.c
+++ b/ld-elf2flt.c
@@ -46,7 +46,6 @@ static const char *elf2flt = NULL;
 static const char *nm = NULL;
 static const char *objdump = NULL;
 static const char *objcopy = NULL;
-static const char *tooldir = ".";
 static const char *ldscriptpath = BINUTILS_LDSCRIPTDIR;
 
 /* A list of sed commands */
@@ -473,47 +472,49 @@ static void parse_args(int argc, char **argv)
 
 int main(int argc, char *argv[])
 {
-       const char *ptr;
-       char *tmp;
        const char *argv0 = argv[0];
-       size_t len;
+       const char *argv0_dir = make_relative_prefix(argv0, "/", "/");
+       char *tooldir = argv0_dir;
+       char *bindir = argv0_dir;
+       char *tmp;
        struct stat buf;
        const char *have_exe = NULL;
        int status;
 
-       len = strlen(argv0);
 #ifdef __WIN32
        /* Remove the .exe extension, if it's there.  */
+       size_t len = strlen(argv0);
        if (len > 4 && streq(&argv0[len - 4], ".exe")) {
                have_exe = ".exe";
                len -= 4;
                argv0 = tmp = xstrdup(argv0);
                tmp[len] = 0;
+               argv[0][len] = '\0';
        }
 #endif
-       elf2flt_progname = argv0;
-       for (ptr = elf2flt_progname + len; ptr != elf2flt_progname; ptr--)
-               if (IS_DIR_SEPARATOR(ptr[-1])) {
-                       tooldir = tmp = xmalloc(len);
-                       memcpy(tmp, argv0, len);
-                       tmp[ptr - elf2flt_progname - 1] = 0;
-                       elf2flt_progname = ptr;
-                       /* The standard binutils tool layout has:
-
-                          bin/<TARGET_ALIAS>-foo
-                          lib/
-                          <TARGET_ALIAS>/bin/foo
-                          <TARGET_ALIAS>/lib
-
-                          It's <TARGET_ALIAS>/ that we want here: files in lib/ are for
-                          the host while those in <TARGET_ALIAS>/lib are for the target.  */
-                       if (streqn(elf2flt_progname, TARGET_ALIAS)) {
-                               tmp = concat(tooldir, "/../" TARGET_ALIAS "/bin", NULL);
-                               if (stat(tmp, &buf) == 0 && S_ISDIR(buf.st_mode))
-                                       tooldir = tmp;
-                       }
-                       break;
-               }
+       elf2flt_progname = lbasename(argv0);
+
+       /* The standard binutils tool layout has:
+
+          bin/<TARGET_ALIAS>-foo
+          lib/
+          <TARGET_ALIAS>/bin/foo
+          <TARGET_ALIAS>/lib
+
+          It's <TARGET_ALIAS>/ that we want here: files in lib/ are for
+          the host while those in <TARGET_ALIAS>/lib are for the target.
+          Make bindir point to the bin dir for bin/<TARGET_ALIAS>-foo.
+          Make tooldir point to the bin dir for <TARGET_ALIAS>/bin/foo.  */
+       if (streqn(elf2flt_progname, TARGET_ALIAS)) {
+               tmp = concat(argv0_dir, "../" TARGET_ALIAS "/bin/", NULL);
+               if (stat(tmp, &buf) == 0 && S_ISDIR(buf.st_mode))
+                       tooldir = tmp;
+       } else {
+               tmp = concat(argv0_dir, "../../bin/", NULL);
+               if (stat(tmp, &buf) == 0 && S_ISDIR(buf.st_mode))
+                       bindir = tmp;
+       }
+
        /* Typically ld-elf2flt is invoked as `ld` which means error
         * messages from it will look like "ld: " which is completely
         * confusing.  So append an identifier to keep things clear.
@@ -522,25 +523,20 @@ int main(int argc, char *argv[])
 
        xmalloc_set_program_name(elf2flt_progname);
 
-       tmp = xmalloc(len + 16);
-       memcpy(tmp, argv0, len);
-       while (len && tmp[len - 1] != '-' && !IS_DIR_SEPARATOR(tmp[len - 1]))
-               len--;
-       tmp[len] = 0;
-
-       linker = concat(tmp, "ld.real", have_exe, NULL);
-       elf2flt = concat(tmp, "elf2flt", have_exe, NULL);
-       nm = concat(tmp, "nm", have_exe, NULL);
-       objdump = concat(tooldir, "/../../bin/", TARGET_ALIAS, "-objdump", have_exe, NULL);
-       objcopy = concat(tooldir, "/../../bin/", TARGET_ALIAS, "-objcopy", have_exe, NULL);
+       linker = concat(tooldir, "ld.real", have_exe, NULL);
+       elf2flt = concat(tooldir, "elf2flt", have_exe, NULL);
+       nm = concat(tooldir, "nm", have_exe, NULL);
+       objdump = concat(bindir, TARGET_ALIAS "-objdump", have_exe, NULL);
+       objcopy = concat(bindir, TARGET_ALIAS "-objcopy", have_exe, NULL);
 
        if (stat(ldscriptpath, &buf) || !S_ISDIR(buf.st_mode))
-               ldscriptpath = concat(tooldir, "/../lib", NULL);
+               ldscriptpath = concat(tooldir, "../lib", NULL);
 
        parse_args(argc, argv);
 
        if (flag_verbose) {
                fprintf(stderr, "argv[0]      = '%s'\n", argv[0]);
+               fprintf(stderr, "bindir       = '%s'\n", bindir);
                fprintf(stderr, "tooldir      = '%s'\n", tooldir);
                fprintf(stderr, "linker       = '%s'\n", linker);
                fprintf(stderr, "elf2flt      = '%s'\n", elf2flt);