From patchwork Tue Jul 27 14:51:29 2010
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Subject: LTO: Handle merged option sections
Date: Tue, 27 Jul 2010 04:51:29 -0000
From: Andi Kleen <andi@firstfloor.org>
X-Patchwork-Id: 60145
Message-Id: <20100727145128.GA32142@basil.fritz.box>
To: gcc-patches@gcc.gnu.org

LTO: Handle merged option sections

This closes one small hole in the merged section "ld -r" handling.
The options section does not have a suffix and can be merged.
Fix the option reader to loop over all copies of the options. 

Passed a bootstrap and full test suite run on x86_64-linux

Ok to commit?

2010-07-27  Andi Kleen <ak@linux.intel.com>

	* lto-opts.c (lto_file_read_options): Add loop over all inputs.


Index: gcc/lto-opts.c
===================================================================
--- gcc/lto-opts.c	(revision 162566)
+++ gcc/lto-opts.c	(working copy)
@@ -349,8 +349,8 @@
 void
 lto_read_file_options (struct lto_file_decl_data *file_data)
 {
-  size_t len;
-  const char *data;
+  size_t len, l, skip;
+  const char *data, *p;
   const struct lto_simple_header *header;
   int32_t opts_offset;
   struct lto_input_block ib;
@@ -358,14 +358,30 @@
   data = lto_get_section_data (file_data, LTO_section_opts, NULL, &len);
   if (!data)
 	  return;
-  header = (const struct lto_simple_header *) data;
-  opts_offset = sizeof (*header);
 
-  lto_check_version (header->lto_header.major_version,
-		     header->lto_header.minor_version);
+  /* Option could be multiple sections merged (through ld -r) 
+     Keep reading all options.  This is ok right now because
+     the options just get mashed together anyways.
+     This will have to be done differently once lto-opts knows
+     how to associate options with different files. */
+  l = len;
+  p = data;
+  do 
+    { 
+      header = (const struct lto_simple_header *) p;
+      opts_offset = sizeof (*header);
 
-  LTO_INIT_INPUT_BLOCK (ib, data + opts_offset, 0, header->main_size);
-  input_options (&ib);
+      lto_check_version (header->lto_header.major_version,
+			 header->lto_header.minor_version);
+      
+      LTO_INIT_INPUT_BLOCK (ib, p + opts_offset, 0, header->main_size);
+      input_options (&ib);
+      
+      skip = header->main_size + opts_offset;
+      l -= skip;
+      p += skip;
+    } 
+  while (l > 0);
 
   lto_free_section_data (file_data, LTO_section_opts, 0, data, len);
 }