[PATCH] Windows/PE: Do not create empty export table.

["Aaron W. LaFramboise" <aaron98wiridge9 at aaronwl dot com>]

Presently, if a DLL has no exports, an export table will be created, but 
it will be empty.  In MS LINK, no export table is created at all in this 
condition.  Both behaviors are valid, as near as I can tell, and both 
produce a DLL that Windows seems to understand.  But it's probably 
better to match MS LINK here.

This patch changes the behavior of ld on PECOFF to match MS LINK in this 
regard.

Credit goes to ReactOS developers and Herve Poussinaeu for suggesting 
this change, which they use locally in their GNU-based toolchain.

Tested on i386-pc-mingw32 by a build and test cycle, with no regressions.

OK to commit?
2004-08-06  Aaron W. LaFramboise <aaron98wiridge9@aaronwl.com>

	* pe-dll.c (process_def_file): Do not create empty export table.

	* ld-pe/exports.d: New file.
	* ld-pe/exports.s: New file.
	* ld-pe/pe.exp: New test for empty export table.

Index: ld/pe-dll.c
===================================================================
RCS file: /cvs/src/src/ld/pe-dll.c,v
retrieving revision 1.107
diff -u -p -r1.107 pe-dll.c
--- ld/pe-dll.c	31 Jul 2008 07:27:52 -0000	1.107
+++ ld/pe-dll.c	7 Aug 2008 05:56:36 -0000
@@ -603,10 +603,9 @@ process_def_file (bfd *abfd ATTRIBUTE_UN
 	}
     }
 
-  /* If we are not building a DLL, when there are no exports
+  /* If there are no exports
      we do not build an export table at all.  */
-  if (!pe_dll_export_everything && pe_def_file->num_exports == 0
-      && info->executable)
+  if (!pe_dll_export_everything && pe_def_file->num_exports == 0)
     return;
 
   /* Now, maybe export everything else the default way.  */
Index: ld/testsuite/ld-pe/exports.d
===================================================================
RCS file: ld/testsuite/ld-pe/exports.d
diff -N ld/testsuite/ld-pe/exports.d
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ld/testsuite/ld-pe/exports.d	7 Aug 2008 05:56:39 -0000
@@ -0,0 +1,4 @@
+#...
+The Data Directory
+Entry 0 00000000 00000000 Export Directory \[\.edata \(or where ever we found it\)\]
+#...
Index: ld/testsuite/ld-pe/exports.s
===================================================================
RCS file: ld/testsuite/ld-pe/exports.s
diff -N ld/testsuite/ld-pe/exports.s
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ld/testsuite/ld-pe/exports.s	7 Aug 2008 05:56:39 -0000
@@ -0,0 +1,2 @@
+# Deliberately left empty.
+
Index: ld/testsuite/ld-pe/pe.exp
===================================================================
RCS file: /cvs/src/src/ld/testsuite/ld-pe/pe.exp,v
retrieving revision 1.8
diff -u -p -r1.8 pe.exp
--- ld/testsuite/ld-pe/pe.exp	6 Aug 2007 14:41:51 -0000	1.8
+++ ld/testsuite/ld-pe/pe.exp	7 Aug 2008 05:56:39 -0000
@@ -38,6 +38,8 @@ if {[istarget x86_64-*-mingw*] } {
   set pe_tests {
     {".secrel32" "" "" {secrel1.s secrel2.s}
      {{objdump -s secrel.d}} "secrel.x"}
+    {"Empty export table" "" "" "exports.s"
+     {{objdump -p exports.d}} "exports.dll"}
   }
 }