1 files changed, 263 insertions, 7 deletions

diff --git a/gcc/gcc.c b/gcc/gcc.c
index c186df30011..6ee6ed1bb65 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -112,13 +112,19 @@ extern void set_std_prefix PROTO((char *, int));
 #define DIR_SEPARATOR '/'
 #endif
 
+/* CYGNUS LOCAL -- meissner/relative pathnames */
+#ifndef DIR_UP
+#define DIR_UP ".."
+#endif
+/* END CYGNUS LOCAL -- meissner/relative pathnames */
+
 static char dir_separator_str[] = {DIR_SEPARATOR, 0};
 
 #define obstack_chunk_alloc xmalloc
 #define obstack_chunk_free free
 
-#ifndef GET_ENVIRONMENT
-#define GET_ENVIRONMENT(ENV_VALUE,ENV_NAME) ENV_VALUE = getenv (ENV_NAME)
+#ifndef GET_ENV_PATH_LIST
+#define GET_ENV_PATH_LIST(VAR,NAME)   do { (VAR) = getenv (NAME); } while (0)
 #endif
 
 extern char *my_strerror PROTO((int));
@@ -217,6 +223,11 @@ static void set_spec		PROTO((char *, char *));
 static struct compiler *lookup_compiler PROTO((char *, size_t, char *));
 static char *build_search_list	PROTO((struct path_prefix *, char *, int));
 static void putenv_from_prefixes PROTO((struct path_prefix *, char *));
+/* CYGNUS LOCAL -- meissner/relative pathnames */
+static char **split_directories PROTO((char *, int *));
+static void free_split_directories PROTO((char **));
+static char *make_relative_prefix PROTO((char *, char *, char *));
+/* END CYGNUS LOCAL -- meissner/relative pathnames */
 static char *find_a_file	PROTO((struct path_prefix *, char *, int));
 static void add_prefix		PROTO((struct path_prefix *, char *, char *,
 				       int, int, int *));
@@ -1420,6 +1431,12 @@ static char *standard_startfile_prefix_2 = "/usr/lib/";
 static char *tooldir_base_prefix = TOOLDIR_BASE_PREFIX;
 static char *tooldir_prefix;
 
+/* CYGNUS LOCAL -- meissner/relative pathnames */
+#ifdef STANDARD_BINDIR_PREFIX
+static char *standard_bindir_prefix = STANDARD_BINDIR_PREFIX;
+#endif
+/* END CYGNUS LOCAL -- meissner/relative pathnames */
+
 /* Subdirectory to use for locating libraries.  Set by
    set_multilib_dir based on the compilation options.  */
 
@@ -1974,6 +1991,234 @@ putenv_from_prefixes (paths, env_var)
   putenv (build_search_list (paths, env_var, 1));
 }
 
+/* CYGNUS LOCAL -- meissner/relative pathnames */
+/* Split a filename into component directories.  */
+
+static char **
+split_directories (name, ptr_num_dirs)
+     char *name;
+     int *ptr_num_dirs;
+{
+  int num_dirs = 0;
+  char **dirs;
+  char *p, *q;
+  int ch;
+
+  /* Count the number of directories.  Special case MSDOS disk names as part
+     of the initial directory.  */
+  p = name;
+  if (DIR_SEPARATOR == '\\' && name[1] == ':'
+      && (name[2] == DIR_SEPARATOR || name[2] == '/'))
+    {
+      p += 3;
+      num_dirs++;
+    }
+
+  while ((ch = *p++) != '\0')
+    {
+      if (ch == '/' || ch == DIR_SEPARATOR)
+        {
+          num_dirs++;
+          while ((ch = *p) == '/' || ch == DIR_SEPARATOR)
+            p++;
+        }
+    }
+
+  dirs = (char **) xmalloc (sizeof (char *) * (num_dirs + 2));
+
+  /* Now copy the directory parts.  */
+  num_dirs = 0;
+  p = name;
+  if (DIR_SEPARATOR == '\\' && name[1] == ':'
+      && (name[2] == DIR_SEPARATOR || name[2] == '/'))
+    {
+      dirs[num_dirs++] = save_string (p, 3);
+      p += 3;
+    }
+
+  q = p;
+  while ((ch = *p++) != '\0')
+    {
+      if (ch == '/' || ch == DIR_SEPARATOR)
+        {
+          while ((ch = *p) == '/' || ch == DIR_SEPARATOR)
+            p++;
+
+          dirs[num_dirs++] = save_string (q, p - q);
+          q = p;
+        }
+    }
+
+  if (p - 1 - q > 0)
+    dirs[num_dirs++] = save_string (q, p - 1 - q);
+
+  dirs[num_dirs] = NULL_PTR;
+  if (ptr_num_dirs)
+    *ptr_num_dirs = num_dirs;
+
+  return dirs;
+}
+
+/* Release storage held by split directories.  */
+
+static void
+free_split_directories (dirs)
+     char **dirs;
+{
+  int i = 0;
+
+  while (dirs[i] != NULL_PTR)
+    free (dirs[i++]);
+
+  free ((char *)dirs);
+}
+
+/* Given three strings PROGNAME, BIN_PREFIX, PREFIX, return a string that gets
+   to PREFIX starting with the directory portion of PROGNAME and a relative
+   pathname of the difference between BIN_PREFIX and PREFIX.
+
+   For example, if BIN_PREFIX is /alpha/beta/gamma/gcc/delta, PREFIX is
+   /alpha/beta/gamma/omega/, and PROGNAME is /red/green/blue/gcc, then this
+   function will return /reg/green/blue/../omega.
+
+   If no relative prefix can be found, return NULL.  */
+
+static char *
+make_relative_prefix (progname, bin_prefix, prefix)
+     char *progname;
+     char *bin_prefix;
+     char *prefix;
+{
+  char **prog_dirs, **bin_dirs, **prefix_dirs;
+  int prog_num, bin_num, prefix_num, std_loc_p;
+  int i, n, common;
+
+  prog_dirs = split_directories (progname, &prog_num);
+  bin_dirs = split_directories (bin_prefix, &bin_num);
+
+  /* If there is no full pathname, try to find the program by checking in each
+     of the directories specified in the PATH environment variable.  */
+  if (prog_num == 1)
+    {
+      char *temp;
+
+      GET_ENV_PATH_LIST (temp, "PATH");
+      if (temp)
+        {
+          char *startp, *endp;
+          char *nstore = (char *) alloca (strlen (temp) + strlen (progname) + 1\
+);
+
+          startp = endp = temp;
+          while (1)
+            {
+              if (*endp == PATH_SEPARATOR || *endp == 0)
+                {
+                  if (endp == startp)
+                    {
+                      nstore[0] = '.';
+                      nstore[1] = DIR_SEPARATOR;
+                      nstore[2] = '\0';
+                    }
+                  else
+                    {
+                      strncpy (nstore, startp, endp-startp);
+                      if (endp[-1] != '/' && endp[-1] != DIR_SEPARATOR)
+                        {
+                          nstore[endp-startp] = DIR_SEPARATOR;
+                          nstore[endp-startp+1] = 0;
+                        }
+                      else
+                        nstore[endp-startp] = 0;
+                    }
+                  strcat (nstore, progname);
+                  if (!access (nstore, X_OK))
+                    {
+                      free_split_directories (prog_dirs);
+                      progname = nstore;
+                      prog_dirs = split_directories (progname, &prog_num);
+                      break;
+                    }
+
+                  if (*endp == 0)
+                    break;
+                  endp = startp = endp + 1;
+                }
+              else
+                endp++;
+            }
+        }
+    }
+
+  /* Remove the program name from comparison of directory names.  */
+  prog_num--;
+
+  /* Determine if the compiler is installed in the standard location, and if
+     so, we don't need to specify relative directories.  Also, if argv[0]
+     doesn't contain any directory specifiers, there is not much we can do.  */
+  std_loc_p = 0;
+  if (prog_num == bin_num)
+    {
+      for (i = 0; i < bin_num; i++)
+        {
+          if (strcmp (prog_dirs[i], bin_dirs[i]) != 0)
+            break;
+        }
+
+      if (prog_num <= 0 || i == bin_num)
+        {
+          std_loc_p = 1;
+          free_split_directories (prog_dirs);
+          free_split_directories (bin_dirs);
+          prog_dirs = bin_dirs = (char **)0;
+          return NULL_PTR;
+        }
+    }
+
+  prefix_dirs = split_directories (prefix, &prefix_num);
+
+  /* Find how many directories are in common between bin_prefix & prefix */
+  n = (prefix_num < bin_num) ? prefix_num : bin_num;
+  for (common = 0; common < n; common++)
+    {
+      if (strcmp (bin_dirs[common], prefix_dirs[common]) != 0)
+        break;
+    }
+
+  /* If there are no common directories, there can be no relative prefix.  */
+  if (common == 0)
+    {
+      free_split_directories (prog_dirs);
+      free_split_directories (bin_dirs);
+      free_split_directories (prefix_dirs);
+      return NULL_PTR;
+    }
+
+  /* Build up the pathnames in argv[0].  */
+  for (i = 0; i < prog_num; i++)
+    obstack_grow (&obstack, prog_dirs[i], strlen (prog_dirs[i]));
+
+  /* Now build up the ..'s.  */
+  for (i = common; i < n; i++)
+    {
+      obstack_grow (&obstack, DIR_UP, sizeof (DIR_UP)-1);
+      obstack_1grow (&obstack, DIR_SEPARATOR);
+    }
+
+  /* Put in directories to move over to prefix.  */
+  for (i = common; i < prefix_num; i++)
+    obstack_grow (&obstack, prefix_dirs[i], strlen (prefix_dirs[i]));
+
+  free_split_directories (prog_dirs);
+  free_split_directories (bin_dirs);
+  free_split_directories (prefix_dirs);
+
+  obstack_1grow (&obstack, '\0');
+  return obstack_finish (&obstack);
+}
+/* END CYGNUS LOCAL -- meissner/relative pathnames */
+
+
 /* Search for NAME using the prefix list PREFIXES.  MODE is passed to
    access to check permissions.
    Return 0 if not found, otherwise return its name, allocated with malloc.  */
@@ -2570,7 +2815,7 @@ process_command (argc, argv)
   int have_o = 0;
   int lang_n_infiles = 0;
 
-  GET_ENVIRONMENT (gcc_exec_prefix, "GCC_EXEC_PREFIX");
+  GET_ENV_PATH_LIST (gcc_exec_prefix, "GCC_EXEC_PREFIX");
 
   n_switches = 0;
   n_infiles = 0;
@@ -2588,7 +2833,18 @@ process_command (argc, argv)
 	}
     }
 
-  /* Set up the default search paths.  */
+  /* CYGNUS LOCAL meissner/relative pathnames */
+  /* Set up the default search paths.  If there is no GCC_EXEC_PREFIX, see if we
+     can create it from the pathname specified in argv[0].  */
+
+  if (!gcc_exec_prefix)
+    {
+      gcc_exec_prefix = make_relative_prefix (argv[0], standard_bindir_prefix,
+                                              standard_exec_prefix);
+      if (gcc_exec_prefix)
+        putenv (concat ("GCC_EXEC_PREFIX=", gcc_exec_prefix, NULL_PTR));
+    }
+  /* END CYGNUS LOCAL -- meissner/relative pathnames */
 
   if (gcc_exec_prefix)
     {
@@ -2613,7 +2869,7 @@ process_command (argc, argv)
   /* COMPILER_PATH and LIBRARY_PATH have values
      that are lists of directory names with colons.  */
 
-  GET_ENVIRONMENT (temp, "COMPILER_PATH");
+  GET_ENV_PATH_LIST (temp, "COMPILER_PATH");
   if (temp)
     {
       char *startp, *endp;
@@ -2647,7 +2903,7 @@ process_command (argc, argv)
 	}
     }
 
-  GET_ENVIRONMENT (temp, "LIBRARY_PATH");
+  GET_ENV_PATH_LIST (temp, "LIBRARY_PATH");
   if (temp && *cross_compile == '0')
     {
       char *startp, *endp;
@@ -2680,7 +2936,7 @@ process_command (argc, argv)
     }
 
   /* Use LPATH like LIBRARY_PATH (for the CMU build program).  */
-  GET_ENVIRONMENT (temp, "LPATH");
+  GET_ENV_PATH_LIST (temp, "LPATH");
   if (temp && *cross_compile == '0')
     {
       char *startp, *endp;