From patchwork Fri Sep  3 21:42:39 2010
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Subject: Allow more WHOPR partitions than souce files
Date: Fri, 03 Sep 2010 11:42:39 -0000
From: Jan Hubicka <hubicka@ucw.cz>
X-Patchwork-Id: 63727
Message-Id: <20100903214239.GP1664@kam.mff.cuni.cz>
To: gcc-patches@gcc.gnu.org, dnovillo@redhat.com, rguenther@suse.de

Hi,
this patch makes collect2 to accept more partition files then number of original .o files
on the command line.  This is needed for my partitioning patch that sometimes (for very
large .o files) decide to break up single .o file into multiple.

Bootstrapped/regtested x86_64-linux, OK?

Honza

	* collect2.c (maybe_run_lto_and_relink): Allow number of partition files
	to exceed number of files.


Index: collect2.c
===================================================================
--- collect2.c	(revision 163809)
+++ collect2.c	(working copy)
@@ -942,12 +942,15 @@ maybe_run_lto_and_relink (char **lto_ld_
     {
       char **lto_c_argv;
       const char **lto_c_ptr;
-      const char **p, **q, **r;
+      const char **p, **q, **r, **last_entry = NULL;
       const char **lto_o_ptr;
       struct lto_object *list;
       char *lto_wrapper = getenv ("COLLECT_LTO_WRAPPER");
       struct pex_obj *pex;
       const char *prog = "lto-wrapper";
+      int lto_ld_argv_size = 0;
+      char **out_lto_ld_argv;
+      size_t num_files;
 
       if (!lto_wrapper)
 	fatal ("COLLECT_LTO_WRAPPER must be set.");
@@ -973,7 +976,7 @@ maybe_run_lto_and_relink (char **lto_ld_
       {
 	int c;
 	FILE *stream;
-	size_t i, num_files;
+	size_t i;
 	char *start, *end;
 
 	stream = pex_read_output (pex, 0);
@@ -1007,10 +1010,14 @@ maybe_run_lto_and_relink (char **lto_ld_
       do_wait (prog, pex);
       pex = NULL;
 
+      for (lto_ld_argv_size = 0; lto_ld_argv[lto_ld_argv_size]; lto_ld_argv_size++)
+	;
+      out_lto_ld_argv = XCNEWVEC(char *, num_files + lto_ld_argv_size + 1);
+      memcpy (out_lto_ld_argv, lto_ld_argv, sizeof (char *) * lto_ld_argv_size);
       /* After running the LTO back end, we will relink, substituting
 	 the LTO output for the object files that we submitted to the
 	 LTO. Here, we modify the linker command line for the relink.  */
-      p = CONST_CAST2 (const char **, char **, lto_ld_argv);
+      p = CONST_CAST2 (const char **, char **, out_lto_ld_argv);
       lto_o_ptr = CONST_CAST2 (const char **, char **, lto_o_files);
 
       while (*p != NULL)
@@ -1023,6 +1030,7 @@ maybe_run_lto_and_relink (char **lto_ld_
                   if (*lto_o_ptr)
                     {
                       /* Replace first argument with LTO output file.  */
+		      last_entry = p;
                       *p++ = *lto_o_ptr++;
                     }
                   else
@@ -1047,15 +1055,27 @@ maybe_run_lto_and_relink (char **lto_ld_
           if (!list) ++p;
         }
 
-      /* The code above assumes we will never have more lto output files than
-	 input files.  Otherwise, we need to resize lto_ld_argv.  Check this
-	 assumption.  */
+      /* Insert remaining .o files just after last file appearing in the argument
+	 sequence.  This way relative position of crtend and friends will be right.  */
       if (*lto_o_ptr)
-	fatal ("too many lto output files");
+	{
+	  size_t remaining_files = 0;
+	  size_t tail_size = 0;
+
+	  for (p = lto_o_ptr; *p; p++)
+	    remaining_files++;
+	  for (p = last_entry + 1; *p; p++)
+	    tail_size++;
+	  memmove (last_entry + 1 + remaining_files,
+		   last_entry + 1,
+		   tail_size * sizeof (char *));
+	  memcpy (last_entry + 1, lto_o_ptr, remaining_files * sizeof (char *));
+	}
 
       /* Run the linker again, this time replacing the object files
          optimized by the LTO with the temporary file generated by the LTO.  */
-      fork_execute ("ld", lto_ld_argv);
+      fork_execute ("ld", out_lto_ld_argv);
+      free (lto_ld_argv);
 
       maybe_unlink_list (lto_o_files);
     }