Introduce exec_file_find

This commit adds a new function, exec_file_find, which computes the
full pathname of the main executable in much the same way solib_find
does for pathnames of shared libraries.  The bulk of the existing
solib_find was moved into a new static function solib_find_1, with
exec_file_find and solib_find being small wrappers for solib_find_1.

gdb/ChangeLog:

	* solist.h (exec_file_find): New declaration.
	* solib.c (solib_find_1): New function, factored out from...
	(solib_find): ...here.
	(exec_file_find): New function.

3 files changed, 110 insertions, 47 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0de7554..bfd70a6 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2015-04-17  Gary Benson <gbenson@redhat.com>
 
+	* solist.h (exec_file_find): New declaration.
+	* solib.c (solib_find_1): New function, factored out from...
+	(solib_find): ...here.
+	(exec_file_find): New function.
+
+2015-04-17  Gary Benson <gbenson@redhat.com>
+
 	* gdbcore.h (exec_file_locate_attach): New declaration.
 	* exec.c (exec_file_locate_attach): New function, factored
 	out from...
diff --git a/gdb/solib.c b/gdb/solib.c
index 31298a7..2466235 100644
--- a/gdb/solib.c
+++ b/gdb/solib.c
@@ -112,13 +112,13 @@ show_solib_search_path (struct ui_file *file, int from_tty,
 #  define DOS_BASED_FILE_SYSTEM 0
 #endif
 
-/* Returns the full pathname of the shared library file, or NULL if
-   not found.  (The pathname is malloc'ed; it needs to be freed by the
-   caller.)  *FD is set to either -1 or an open file handle for the
-   library.
+/* Return the full pathname of a binary file (the main executable
+   or a shared library file), or NULL if not found.  The returned
+   pathname is malloc'ed and must be freed by the caller.  *FD is
+   set to either -1 or an open file handle for the binary file.
 
    Global variable GDB_SYSROOT is used as a prefix directory
-   to search for shared libraries if they have an absolute path.
+   to search for binary files 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
@@ -128,58 +128,36 @@ show_solib_search_path (struct ui_file *file, int from_tty,
    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 either the sysroot (if set) or
-   the local filesystem.
+   the local filesystem.  SOLIB_SEARCH_PATH is not used when searching
+   for the main executable.
 
    Search algorithm:
    * 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 IS_SOLIB is non-zero:
+   *   Look in SOLIB_SEARCH_PATH.
+   *   If available, use target defined search function.
    * If NO sysroot is set, perform the following two searches:
    *   Look in inferior's $PATH.
-   *   Look in inferior's $LD_LIBRARY_PATH.
+   *   If IS_SOLIB is non-zero:
+   *     Look in inferior's $LD_LIBRARY_PATH.
    *
    * The last check avoids doing this search when targetting remote
    * machines since a sysroot will almost always be set.
 */
 
-char *
-solib_find (char *in_pathname, int *fd)
+static char *
+solib_find_1 (char *in_pathname, int *fd, int is_solib)
 {
   const struct target_so_ops *ops = solib_ops (target_gdbarch ());
   int found_file = -1;
   char *temp_pathname = NULL;
-  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 = gdb_sysroot;
 
-  /* If solib_symbols_extension is set, replace the file's
-     extension.  */
-  if (solib_symbols_extension)
-    {
-      char *p = in_pathname + strlen (in_pathname);
-
-      while (p > in_pathname && *p != '.')
-	p--;
-
-      if (*p == '.')
-	{
-	  char *new_pathname;
-
-	  new_pathname = alloca (p - in_pathname + 1
-				 + strlen (solib_symbols_extension) + 1);
-	  memcpy (new_pathname, in_pathname, p - in_pathname + 1);
-	  strcpy (new_pathname + (p - in_pathname) + 1,
-		  solib_symbols_extension);
-
-	  in_pathname = new_pathname;
-	}
-    }
-
   if (sysroot != NULL)
     {
       /* If the absolute prefix starts with "target:" but the
@@ -351,23 +329,26 @@ solib_find (char *in_pathname, int *fd)
 	in_pathname++;
     }
 
-  /* If not found, search the solib_search_path (if any).  */
-  if (found_file < 0 && solib_search_path != NULL)
+  /* If not found, and we're looking for a solib, search the
+     solib_search_path (if any).  */
+  if (is_solib && found_file < 0 && solib_search_path != NULL)
     found_file = openp (solib_search_path,
 			OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH,
 			in_pathname, O_RDONLY | O_BINARY, &temp_pathname);
 
-  /* If not found, next search the solib_search_path (if any) for the basename
-     only (ignoring the path).  This is to allow reading solibs from a path
-     that differs from the opened path.  */
-  if (found_file < 0 && solib_search_path != NULL)
+  /* If not found, and we're looking for a solib, next search the
+     solib_search_path (if any) for the basename only (ignoring the
+     path).  This is to allow reading solibs from a path that differs
+     from the opened path.  */
+  if (is_solib && found_file < 0 && solib_search_path != NULL)
     found_file = openp (solib_search_path,
 			OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH,
 			target_lbasename (fskind, in_pathname),
 			O_RDONLY | O_BINARY, &temp_pathname);
 
-  /* If not found, try to use target supplied solib search method.  */
-  if (found_file < 0 && ops->find_and_open_solib)
+  /* If not found, and we're looking for a solib, try to use target
+     supplied solib search method.  */
+  if (is_solib && found_file < 0 && ops->find_and_open_solib)
     found_file = ops->find_and_open_solib (in_pathname, O_RDONLY | O_BINARY,
 					   &temp_pathname);
 
@@ -378,9 +359,9 @@ solib_find (char *in_pathname, int *fd)
 			OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
 			O_RDONLY | O_BINARY, &temp_pathname);
 
-  /* If not found, next search the inferior's $LD_LIBRARY_PATH
-     environment variable.  */
-  if (found_file < 0 && sysroot == NULL)
+  /* If not found, and we're looking for a solib, next search the
+     inferior's $LD_LIBRARY_PATH environment variable.  */
+  if (is_solib && 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,
@@ -390,6 +371,78 @@ solib_find (char *in_pathname, int *fd)
   return temp_pathname;
 }
 
+/* Return the full pathname of the main executable, or NULL if not
+   found.  The returned pathname is malloc'ed and must be freed by
+   the caller.  *FD is set to either -1 or an open file handle for
+   the main executable.
+
+   The search algorithm used is described in solib_find_1's comment
+   above.  */
+
+char *
+exec_file_find (char *in_pathname, int *fd)
+{
+  char *result = solib_find_1 (in_pathname, fd, 0);
+
+  if (result == NULL)
+    {
+      const char *fskind = effective_target_file_system_kind ();
+
+      if (fskind == file_system_kind_dos_based)
+	{
+	  char *new_pathname;
+
+	  new_pathname = alloca (strlen (in_pathname) + 5);
+	  strcpy (new_pathname, in_pathname);
+	  strcat (new_pathname, ".exe");
+
+	  result = solib_find_1 (new_pathname, fd, 0);
+	}
+    }
+
+  return result;
+}
+
+/* Return the full pathname of a shared library file, or NULL if not
+   found.  The returned pathname is malloc'ed and must be freed by
+   the caller.  *FD is set to either -1 or an open file handle for
+   the shared library.
+
+   The search algorithm used is described in solib_find_1's comment
+   above.  */
+
+char *
+solib_find (char *in_pathname, int *fd)
+{
+  const char *solib_symbols_extension
+    = gdbarch_solib_symbols_extension (target_gdbarch ());
+
+  /* If solib_symbols_extension is set, replace the file's
+     extension.  */
+  if (solib_symbols_extension != NULL)
+    {
+      char *p = in_pathname + strlen (in_pathname);
+
+      while (p > in_pathname && *p != '.')
+	p--;
+
+      if (*p == '.')
+	{
+	  char *new_pathname;
+
+	  new_pathname = alloca (p - in_pathname + 1
+				 + strlen (solib_symbols_extension) + 1);
+	  memcpy (new_pathname, in_pathname, p - in_pathname + 1);
+	  strcpy (new_pathname + (p - in_pathname) + 1,
+		  solib_symbols_extension);
+
+	  in_pathname = new_pathname;
+	}
+    }
+
+  return solib_find_1 (in_pathname, fd, 1);
+}
+
 /* Open and return a BFD for the shared library PATHNAME.  If FD is not -1,
    it is used as file handle to open the file.  Throws an error if the file
    could not be opened.  Handles both local and remote file access.
diff --git a/gdb/solist.h b/gdb/solist.h
index 148bec1..7021f5c 100644
--- a/gdb/solist.h
+++ b/gdb/solist.h
@@ -176,6 +176,9 @@ void free_so (struct so_list *so);
 /* Return address of first so_list entry in master shared object list.  */
 struct so_list *master_so_list (void);
 
+/* Find main executable binary file.  */
+extern char *exec_file_find (char *in_pathname, int *fd);
+
 /* Find shared library binary file.  */
 extern char *solib_find (char *in_pathname, int *fd);