[PATCH] -fdump-tree, -save-temps=obj & subdirs

https://gcc.gnu.org/ml/gcc-patches/2017-12/msg00377.html
	* opts.c (finish_options): Don't prefix dump_base_name if it
	already contains directories.

From-SVN: r255820

gcc/ChangeLog

+2017-12-19  Nathan Sidwell  <nathan@acm.org>
+
+	* opts.c (finish_options): Don't prefix dump_base_name if it
+	already contains directories.
+
 2017-12-19  Martin Liska  <mliska@suse.cz>
 
 	PR rtl-optimization/82675

gcc/opts.c

@@ -700,19 +700,27 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
   enum unwind_info_type ui_except;
 
   if (opts->x_dump_base_name
-      && ! IS_ABSOLUTE_PATH (opts->x_dump_base_name)
       && ! opts->x_dump_base_name_prefixed)
     {
-      /* First try to make OPTS->X_DUMP_BASE_NAME relative to the
-	 OPTS->X_DUMP_DIR_NAME directory.  Then try to make
-	 OPTS->X_DUMP_BASE_NAME relative to the OPTS->X_AUX_BASE_NAME
-	 directory, typically the directory to contain the object
-	 file.  */
-      if (opts->x_dump_dir_name)
+      const char *sep = opts->x_dump_base_name;
+
+      for (; *sep; sep++)
+	if (IS_DIR_SEPARATOR (*sep))
+	  break;
+
+      if (*sep)
+	/* If dump_base_path contains subdirectories, don't prepend
+	   anything.  */;
+      else if (opts->x_dump_dir_name)
+	/* We have a DUMP_DIR_NAME, prepend that.  */
 	opts->x_dump_base_name = opts_concat (opts->x_dump_dir_name,
 					      opts->x_dump_base_name, NULL);
       else if (opts->x_aux_base_name
 	       && strcmp (opts->x_aux_base_name, HOST_BIT_BUCKET) != 0)
+	/* AUX_BASE_NAME is set and is not the bit bucket.  If it
+	   contains a directory component, prepend those directories.
+	   Typically this places things in the same directory as the
+	   object file.  */
 	{
 	  const char *aux_base;
 
@@ -731,7 +739,9 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
 	      opts->x_dump_base_name = new_dump_base_name;
 	    }
 	}
-	opts->x_dump_base_name_prefixed = true;
+
+      /* It is definitely prefixed now.  */
+      opts->x_dump_base_name_prefixed = true;
     }
 
   /* Handle related options for unit-at-a-time, toplevel-reorder, and