[Patch/ld] Fix pe-dll.c exclusion of MS-formatted (ILF) import lib internals when exporting symbols

["Danny Smith" <dansmister at gmail dot com>]

When using --the export-all switch (explicitly or by default) for
building a PE .dll, the inclusion of of a MS-style (ILF) import lib,
causes bogus identifiers to be added to the export table.

For example, from Mingw-Bug reported at:
https://sourceforge.net/tracker/index.php?func=detail&aid=1901008&group_id=2435&atid=102435

With function.o containing a dependency on the MS PSDK library
wlanapi.dll, and using the MS import lib wlanapi.lib (in current dir)
to resolve that
dependency


	ld -L./ -shared -o library.dll --output-def bad_syntax.def function.o -lwlanapi


produces the error
Cannot export Wlanapi_NULL_THUNK_DATA: symbol not found

and creates the bad_syntax.def file
EXPORTS
    .idata$4 @1 DATA
    .idata$5 @2 DATA
    .idata$6 @3 DATA
    _IMPORT_DESCRIPTOR_Wlanapi @4 DATA
    _NULL_IMPORT_DESCRIPTOR @5 DATA
    function @6
    Wlanapi_NULL_THUNK_DATA DATA


The following patch fixes by filtering out these strings
(_IMPORT_DESCRIPTOR_. _NULL_THUNK_DATA, _NULL_IMPORT_DESCRIPTOR) used
internally by ILF libs, and extends the exclusion of the ".text" label to
all symbols starting with  ".".

OK to commit?


2008-07-05  Danny Smith  <dannysmith@users.sourceforge.net>

	*pe-dll.c (autofilter_symbolprefixlist): Excude all symbols
	starting with ".".
	Exclude "_IMPORT_DESCRIPTOR_".
	(autofilter_symbolsuffixlist): Exclude "_NULL_THUNK_DATA".
	(autofilter_symbollist_generic): Don't check for ".text".
	Exclude STRING_COMMA_LEN ("_NULL_IMPORT_DESCRIPTOR".
	(autofilter_symbollist_i386): Likewise.

Index: pe-dll.c
===================================================================
RCS file: /cvs/src/src/ld/pe-dll.c,v
retrieving revision 1.105
diff -c -3 -p -r1.105 pe-dll.c
*** pe-dll.c	27 May 2008 08:34:26 -0000	1.105
--- pe-dll.c	5 Jul 2008 09:41:33 -0000
*************** pe_details_type;
*** 187,193 ****

  static const autofilter_entry_type autofilter_symbollist_generic[] =
  {
!   { STRING_COMMA_LEN (".text") },
    /* Entry point symbols.  */
    { STRING_COMMA_LEN ("DllMain") },
    { STRING_COMMA_LEN ("DllMainCRTStartup") },
--- 187,193 ----

  static const autofilter_entry_type autofilter_symbollist_generic[] =
  {
!   { STRING_COMMA_LEN ("_NULL_IMPORT_DESCRIPTOR") },
    /* Entry point symbols.  */
    { STRING_COMMA_LEN ("DllMain") },
    { STRING_COMMA_LEN ("DllMainCRTStartup") },
*************** static const autofilter_entry_type autof
*** 200,206 ****

  static const autofilter_entry_type autofilter_symbollist_i386[] =
  {
!   { STRING_COMMA_LEN (".text") },
    /* Entry point symbols, and entry hooks.  */
    { STRING_COMMA_LEN ("cygwin_crt0") },
  #ifdef pe_use_x86_64
--- 200,206 ----

  static const autofilter_entry_type autofilter_symbollist_i386[] =
  {
!   { STRING_COMMA_LEN ("_NULL_IMPORT_DESCRIPTOR") },
    /* Entry point symbols, and entry hooks.  */
    { STRING_COMMA_LEN ("cygwin_crt0") },
  #ifdef pe_use_x86_64
*************** static const autofilter_entry_type autof
*** 350,361 ****
--- 350,366 ----
    { STRING_COMMA_LEN ("_nm_") },
    /* Don't export symbols specifying internal DLL layout.  */
    { STRING_COMMA_LEN ("_head_") },
+   { STRING_COMMA_LEN ("_IMPORT_DESCRIPTOR_") },
+   /* Don't export section labels or artificial symbols
+   (eg ".weak.foo".  */
+   { STRING_COMMA_LEN (".") },
    { NULL, 0 }
  };

  static const autofilter_entry_type autofilter_symbolsuffixlist[] =
  {
    { STRING_COMMA_LEN ("_iname") },
+   { STRING_COMMA_LEN ("_NULL_THUNK_DATA") },
    { NULL, 0 }
  };