From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mumit Khan <khan@xraylith.wisc.EDU>
To: binutils@sourceware.cygnus.com
Subject: (patch) pe-coff shared section flag
Date: Fri, 06 Aug 1999 23:47:00 -0000
Message-id: <199908070537.AAA16135@mercury.xraylith.wisc.edu>
X-SW-Source: 1999-08/msg00042.html

pe-coff has a facility for sharing data among executables/DLLs via
shared segments. This patch allows a named section to be sharable
by adding a 's' flag to the existing set of section flags. 

Patch against 1999-07-21 snapshot, but should apply cleanly against
the current tree. I did try the current CVS, but it produces
executables that windows refuses to run, with or without my
change (I'd like to blame Donn Terry, but probably need some evidence 
first ;-).

GCC of course needs to be update to allow for this, and the patch
is on its way.
  
  int __attribute__((section("my_shared_data"),shared) foo = 0;

will put foo in a named section called "my_share_data" and make it 
shareable among all running copies of the executable.

bfd/ChangeLog:

Fri Aug  6 23:41:35 1999  Mumit Khan  <khan@xraylith.wisc.edu>

	* section.c (SEC_SHARED): Define.
	* bfd-in2.h: Rebuild.
	* bfd/coffcode.h (sec_to_styp_flags): Handle SEC_SHARED. 
	(styp_to_sec_flags): Likewise.
	* peicode.h (coff_swap_scnhdr_out): Likewise.

gas/ChangeLog:
Fri Aug  6 23:44:22 1999  Mumit Khan  <khan@xraylith.wisc.edu>

	* config/obj-coff.c (obj_coff_section): Handle 's' (shared) section 
	flag.

Index: bfd/section.c
===================================================================
RCS file: /cvs/binutils/binutils/bfd/section.c,v
retrieving revision 1.5
diff -u -3 -p -r1.5 section.c
--- bfd/section.c	1999/07/11 19:49:43	1.5
+++ bfd/section.c	1999/08/07 06:37:21
@@ -311,6 +311,9 @@ CODE_FRAGMENT
 .	   "near" the GP.  *}
 .#define SEC_SHORT 0x2000000
 .
+.	{* This section contains "shared" data. Only used on PE-coff.  *}
+.#define SEC_SHARED 0x4000000
+.
 .	{*  End of section flags.  *}
 .
 .	{* Some internal packed boolean fields.  *}
Index: bfd/bfd-in2.h
===================================================================
RCS file: /cvs/binutils/binutils/bfd/bfd-in2.h,v
retrieving revision 1.14
diff -u -3 -p -r1.14 bfd-in2.h
--- bfd/bfd-in2.h	1999/07/19 14:55:15	1.14
+++ bfd/bfd-in2.h	1999/08/07 06:37:21
@@ -1008,6 +1008,9 @@ typedef struct sec
           "near" the GP.  */
 #define SEC_SHORT 0x2000000
 
+        /* This section contains "shared" data. Only used on PE-coff.  */
+#define SEC_SHARED 0x4000000
+
         /*  End of section flags.  */
 
         /* Some internal packed boolean fields.  */
Index: bfd/coffcode.h
===================================================================
RCS file: /cvs/binutils/binutils/bfd/coffcode.h,v
retrieving revision 1.7
diff -u -3 -p -r1.7 coffcode.h
--- bfd/coffcode.h	1999/07/19 14:55:15	1.7
+++ bfd/coffcode.h	1999/08/07 06:37:22
@@ -443,6 +443,8 @@ sec_to_styp_flags (sec_name, sec_flags)
 #ifdef COFF_WITH_PE
   if (sec_flags & SEC_LINK_ONCE)
     styp_flags |= IMAGE_SCN_LNK_COMDAT;
+  if (sec_flags & SEC_SHARED)
+    styp_flags |= IMAGE_SCN_MEM_SHARED;
 #endif
 
   return (styp_flags);
@@ -576,6 +578,9 @@ styp_to_sec_flags (abfd, hdr, name)
 #ifdef COFF_WITH_PE
   if (styp_flags & IMAGE_SCN_LNK_REMOVE)
     sec_flags |= SEC_EXCLUDE;
+
+  if (styp_flags & IMAGE_SCN_MEM_SHARED)
+    sec_flags |= SEC_SHARED;
 
   if (styp_flags & IMAGE_SCN_LNK_COMDAT)
     {
Index: bfd/peicode.h
===================================================================
RCS file: /cvs/binutils/binutils/bfd/peicode.h,v
retrieving revision 1.6
diff -u -3 -p -r1.6 peicode.h
--- bfd/peicode.h	1999/07/12 10:29:58	1.6
+++ bfd/peicode.h	1999/08/07 06:37:22
@@ -1239,6 +1239,8 @@ coff_swap_scnhdr_out (abfd, in, out)
 	flags |= IMAGE_SCN_MEM_READ;
 	if (! (flags & SEC_READONLY))
 	  flags |= IMAGE_SCN_MEM_WRITE;
+	if (flags & SEC_SHARED)
+	  flags |= IMAGE_SCN_MEM_SHARED;
       }
 
     bfd_h_put_32(abfd, flags, (bfd_byte *) scnhdr_ext->s_flags);
Index: gas/config/obj-coff.c
===================================================================
RCS file: /cvs/binutils/binutils/gas/config/obj-coff.c,v
retrieving revision 1.6
diff -u -3 -p -r1.6 obj-coff.c
--- gas/config/obj-coff.c	1999/06/26 19:35:44	1.6
+++ gas/config/obj-coff.c	1999/08/07 06:37:23
@@ -1193,6 +1193,7 @@ coff_frob_file_after_relocs ()
  *						 'd' (apparently m88k for data)
  *                                               'x' for text
  *						 'r' for read-only data
+ *						 's' for shared data (pe-coff)
  * But if the argument is not a quoted string, treat it as a
  * subsegment number.
  */
@@ -1250,6 +1251,7 @@ obj_coff_section (ignore)
 		case 'w': flags |= SEC_DATA; flags &=~ SEC_READONLY; break;
 		case 'x': flags |= SEC_CODE; break;
 		case 'r': flags |= SEC_READONLY; break;
+		case 's': flags |= SEC_SHARED; break;
 
 		case 'i': /* STYP_INFO */
 		case 'l': /* STYP_LIB */

Regards,
Mumit