[PATCH 6/9] Strip "target:" prefix in solib_find if accessing local files

[Gary Benson <gbenson@redhat.com>]

This commit updates solib_find to strip the "target:" prefix from
gdb_sysroot when accessing local files.  This ensures that the same
search algorithm is used for local files regardless of whether a
"target:" prefix was used or not.  It also avoids cluttering GDB's
output with unnecessary "target:" prefixes on paths.

gdb/ChangeLog:

	* solib.c (solib_find): Strip "target:" prefix from sysroot
	if accessing local files.
---
 gdb/ChangeLog |    5 +++++
 gdb/solib.c   |   51 +++++++++++++++++++++++++++++++++++----------------
 2 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/gdb/solib.c b/gdb/solib.c
index 039f529..359a208 100644
--- a/gdb/solib.c
+++ b/gdb/solib.c
@@ -119,24 +119,30 @@ show_solib_search_path (struct ui_file *file, int from_tty,
 
    Global variable GDB_SYSROOT is used as a prefix directory
    to search for shared libraries if they have an absolute path.
+   If GDB_SYSROOT starts with "target:" and target filesystem
+   is the local filesystem then the "target:" prefix will be
+   stripped before the search starts.  This ensures that the
+   same search algorithm is used for local files regardless of
+   whether a "target:" prefix was used.
 
    Global variable SOLIB_SEARCH_PATH is used as a prefix directory
    (or set of directories, as in LD_LIBRARY_PATH) to search for all
-   shared libraries if not found in GDB_SYSROOT.
+   shared libraries if not found in either the sysroot (if set) or
+   the local filesystem.
 
    Search algorithm:
-   * If there is a gdb_sysroot and path is absolute:
-   *   Search for gdb_sysroot/path.
+   * If a sysroot is set and path is absolute:
+   *   Search for sysroot/path.
    * else
    *   Look for it literally (unmodified).
    * Look in SOLIB_SEARCH_PATH.
    * If available, use target defined search function.
-   * If gdb_sysroot is NOT set, perform the following two searches:
+   * If NO sysroot is set, perform the following two searches:
    *   Look in inferior's $PATH.
    *   Look in inferior's $LD_LIBRARY_PATH.
    *
    * The last check avoids doing this search when targetting remote
-   * machines since gdb_sysroot will almost always be set.
+   * machines since a sysroot will almost always be set.
 */
 
 char *
@@ -145,12 +151,11 @@ solib_find (char *in_pathname, int *fd)
   const struct target_so_ops *ops = solib_ops (target_gdbarch ());
   int found_file = -1;
   char *temp_pathname = NULL;
-  int gdb_sysroot_is_empty;
   const char *solib_symbols_extension
     = gdbarch_solib_symbols_extension (target_gdbarch ());
   const char *fskind = effective_target_file_system_kind ();
   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
-  char *sysroot = NULL;
+  char *sysroot = gdb_sysroot;
 
   /* If solib_symbols_extension is set, replace the file's
      extension.  */
@@ -175,18 +180,32 @@ solib_find (char *in_pathname, int *fd)
 	}
     }
 
-  gdb_sysroot_is_empty = (gdb_sysroot == NULL || *gdb_sysroot == 0);
+  if (sysroot != NULL)
+    {
+      /* If the absolute prefix starts with "target:" but the
+	 filesystem accessed by the target_fileio_* methods
+	 is the local filesystem then we strip the "target:"
+	 prefix now and work with the local filesystem.  This
+	 ensures that the same search algorithm is used for
+	 all local files regardless of whether a "target:"
+	 prefix was used.  */
+      if (is_target_filename (sysroot) && target_filesystem_is_local)
+	sysroot += strlen (TARGET_SYSROOT_PREFIX);
+
+      if (*sysroot == '\0')
+	sysroot = NULL;
+    }
 
-  if (!gdb_sysroot_is_empty)
+  if (sysroot != NULL)
     {
-      int prefix_len = strlen (gdb_sysroot);
+      int prefix_len = strlen (sysroot);
 
       /* Remove trailing slashes from absolute prefix.  */
       while (prefix_len > 0
-	     && IS_DIR_SEPARATOR (gdb_sysroot[prefix_len - 1]))
+	     && IS_DIR_SEPARATOR (sysroot[prefix_len - 1]))
 	prefix_len--;
 
-      sysroot = savestring (gdb_sysroot, prefix_len);
+      sysroot = savestring (sysroot, prefix_len);
       make_cleanup (xfree, sysroot);
     }
 
@@ -222,7 +241,7 @@ solib_find (char *in_pathname, int *fd)
        3rd attempt, c:/foo/bar.dll ==> /sysroot/foo/bar.dll
   */
 
-  if (!IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname) || gdb_sysroot_is_empty)
+  if (!IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname) || sysroot == NULL)
     temp_pathname = xstrdup (in_pathname);
   else
     {
@@ -273,7 +292,7 @@ solib_find (char *in_pathname, int *fd)
        c:/foo/bar.dll ==> /sysroot/c/foo/bar.dll.  */
 
   if (found_file < 0
-      && !gdb_sysroot_is_empty
+      && sysroot != NULL
       && HAS_TARGET_DRIVE_SPEC (fskind, in_pathname))
     {
       int need_dir_separator = !IS_DIR_SEPARATOR (in_pathname[2]);
@@ -353,7 +372,7 @@ solib_find (char *in_pathname, int *fd)
 					   &temp_pathname);
 
   /* If not found, next search the inferior's $PATH environment variable.  */
-  if (found_file < 0 && gdb_sysroot_is_empty)
+  if (found_file < 0 && sysroot == NULL)
     found_file = openp (get_in_environ (current_inferior ()->environment,
 					"PATH"),
 			OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
@@ -361,7 +380,7 @@ solib_find (char *in_pathname, int *fd)
 
   /* If not found, next search the inferior's $LD_LIBRARY_PATH
      environment variable.  */
-  if (found_file < 0 && gdb_sysroot_is_empty)
+  if (found_file < 0 && sysroot == NULL)
     found_file = openp (get_in_environ (current_inferior ()->environment,
 					"LD_LIBRARY_PATH"),
 			OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
-- 
1.7.1