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Re: ld -e number makes an entry in symbol table


This is what I ended up committing.  One of my questions regarding
why -e and ENTRY should be treated differently is answered in the
comment..

     	PR ld/6766
	* lexsup.c (parse_args <-e>): Revert 2009-03-18 change.
	* ldemul.c (after_parse_default): Add entry symbol as undef.
	* emultempl/alphaelf.em (alpha_after_parse): Call after_parse_default.
	* emultempl/cr16elf.em (cr16elf_after_parse): Likewise.
	* emultempl/crxelf.em (crxelf_after_parse): Likewise.
	* emultempl/hppaelf.em (hppaelf_after_parse): Likewise.
	* emultempl/ia64elf.em (gld${EMULATION_NAME}_after_parse): Likewise.
	* emultempl/pe.em (gld_${EMULATION_NAME}_after_parse): Call
	after_parse_default and delete now duplicate code.
	* emultempl/pep.em (gld_${EMULATION_NAME}_after_parse): Likewise.
	* scripttempl/elf32cr16.sc: No need to make entry extern.
	* scripttempl/elf32cr16c.sc: Likewise.
	* scripttempl/elf32crx.sc: Likewise.
	* scripttempl/elf32xc16xs.sc: Only provide ENTRY on final link.

Index: ld/ldemul.c
===================================================================
RCS file: /cvs/src/src/ld/ldemul.c,v
retrieving revision 1.32
diff -u -p -r1.32 ldemul.c
--- ld/ldemul.c	30 Aug 2009 05:47:43 -0000	1.32
+++ ld/ldemul.c	12 Sep 2009 06:46:05 -0000
@@ -192,9 +192,35 @@ ldemul_default_target (int argc ATTRIBUT
   return ld_emulation->target_name;
 }
 
+/* If the entry point was not specified as an address, then add the
+   symbol as undefined.  This will cause ld to extract an archive
+   element defining the entry if ld is linking against such an archive.
+
+   We don't do this when generating shared libraries unless given -e
+   on the command line, because most shared libs are not designed to
+   be run as an executable.  However, some are, eg. glibc ld.so and
+   may rely on the default linker script supplying ENTRY.  So we can't
+   remove the ENTRY from the script, but would rather not insert
+   undefined _start syms.  */
+
 void
 after_parse_default (void)
 {
+  if (entry_symbol.name != NULL
+      && (link_info.executable || entry_from_cmdline))
+    {
+      bfd_boolean is_vma = FALSE;
+
+      if (entry_from_cmdline)
+	{
+	  const char *send;
+
+	  bfd_scan_vma (entry_symbol.name, &send, 0);
+	  is_vma = *send == '\0';
+	}
+      if (!is_vma)
+	ldlang_add_undef (entry_symbol.name);
+    }
 }
 
 void
Index: ld/lexsup.c
===================================================================
RCS file: /cvs/src/src/ld/lexsup.c,v
retrieving revision 1.113
diff -u -p -r1.113 lexsup.c
--- ld/lexsup.c	2 Sep 2009 07:25:35 -0000	1.113
+++ ld/lexsup.c	12 Sep 2009 06:46:06 -0000
@@ -828,7 +828,6 @@ parse_args (unsigned argc, char **argv)
 	  break;
 	case 'e':
 	  lang_add_entry (optarg, TRUE);
-	  ldlang_add_undef (optarg);
 	  break;
 	case 'f':
 	  if (command_line.auxiliary_filters == NULL)
Index: ld/emultempl/alphaelf.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/alphaelf.em,v
retrieving revision 1.14
diff -u -p -r1.14 alphaelf.em
--- ld/emultempl/alphaelf.em	2 Sep 2009 07:25:35 -0000	1.14
+++ ld/emultempl/alphaelf.em	12 Sep 2009 06:46:06 -0000
@@ -80,6 +80,8 @@ alpha_after_parse (void)
 				   exp_intop (ALPHA_TEXT_START_32BIT),
 				   exp_nameop (SIZEOF_HEADERS, NULL)),
 			NULL);
+
+  after_parse_default ();
 }
 
 static void
Index: ld/emultempl/cr16elf.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/cr16elf.em,v
retrieving revision 1.5
diff -u -p -r1.5 cr16elf.em
--- ld/emultempl/cr16elf.em	2 Sep 2009 07:25:35 -0000	1.5
+++ ld/emultempl/cr16elf.em	12 Sep 2009 06:46:06 -0000
@@ -1,5 +1,5 @@
 # This shell script emits a C file. -*- C -*-
-# Copyright 2007, 2008 Free Software Foundation, Inc.
+# Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 # Contributed by M R Swami Reddy <MR.Swami.Reddy@nsc.com>
 #
 # This file is part of the GNU Binutils.
@@ -121,6 +121,8 @@ cr16elf_after_parse (void)
      meaninful in CR16 embedded systems. Moreover, when magic_demand_paged
      is true the link sometimes fails.  */
   config.magic_demand_paged = FALSE;
+
+  after_parse_default ();
 }
 
 /* This is called after the sections have been attached to output
Index: ld/emultempl/crxelf.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/crxelf.em,v
retrieving revision 1.6
diff -u -p -r1.6 crxelf.em
--- ld/emultempl/crxelf.em	2 Sep 2009 07:25:35 -0000	1.6
+++ ld/emultempl/crxelf.em	12 Sep 2009 06:46:06 -0000
@@ -1,5 +1,5 @@
 # This shell script emits a C file. -*- C -*-
-#   Copyright 2004, 2005, 2007
+#   Copyright 2004, 2005, 2007, 2009
 #   Free Software Foundation, Inc.
 #
 # This file is part of the GNU Binutils.
@@ -45,6 +45,8 @@ crxelf_after_parse (void)
      meaninful in CRX embedded systems. Moreover, when magic_demand_paged
      is true the link sometimes fails.  */
   config.magic_demand_paged = FALSE;
+
+  after_parse_default ();
 }
 
 /* This is called after the sections have been attached to output
Index: ld/emultempl/hppaelf.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/hppaelf.em,v
retrieving revision 1.54
diff -u -p -r1.54 hppaelf.em
--- ld/emultempl/hppaelf.em	2 Sep 2009 07:25:35 -0000	1.54
+++ ld/emultempl/hppaelf.em	12 Sep 2009 06:46:06 -0000
@@ -59,6 +59,8 @@ hppaelf_after_parse (void)
      			  lang_input_file_is_l_enum,
 			  NULL);
   */
+
+  after_parse_default ();
 }
 
 /* This is called before the input files are opened.  We create a new
Index: ld/emultempl/ia64elf.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/ia64elf.em,v
retrieving revision 1.9
diff -u -p -r1.9 ia64elf.em
--- ld/emultempl/ia64elf.em	2 Sep 2009 07:25:35 -0000	1.9
+++ ld/emultempl/ia64elf.em	12 Sep 2009 06:46:06 -0000
@@ -1,5 +1,5 @@
 # This shell script emits a C file. -*- C -*-
-#   Copyright 2003, 2005, 2006, 2007 Free Software Foundation, Inc.
+#   Copyright 2003, 2005, 2006, 2007, 2009 Free Software Foundation, Inc.
 #
 # This file is part of the GNU Binutils.
 #
@@ -35,6 +35,8 @@ gld${EMULATION_NAME}_after_parse (void)
 {
   link_info.relax_pass = 2;
   bfd_elf${ELFSIZE}_ia64_after_parse (itanium);
+
+  after_parse_default ();
 }
 
 EOF
Index: ld/emultempl/pe.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/pe.em,v
retrieving revision 1.150
diff -u -p -r1.150 pe.em
--- ld/emultempl/pe.em	15 May 2009 14:22:35 -0000	1.150
+++ ld/emultempl/pe.em	12 Sep 2009 06:46:07 -0000
@@ -877,27 +877,13 @@ gld_${EMULATION_NAME}_set_symbols (void)
 static void
 gld_${EMULATION_NAME}_after_parse (void)
 {
-  /* The Windows libraries are designed for the linker to treat the
-     entry point as an undefined symbol.  Otherwise, the .obj that
-     defines mainCRTStartup is brought in because it is the first
-     encountered in libc.lib and it has other symbols in it which will
-     be pulled in by the link process.  To avoid this, we act as
-     though the user specified -u with the entry point symbol.
-
-     This function is called after the linker script and command line
-     options have been read, so at this point we know the right entry
-     point.  This function is called before the input files are
-     opened, so registering the symbol as undefined will make a
-     difference.  */
-
-  if (! link_info.relocatable && entry_symbol.name != NULL)
-    ldlang_add_undef (entry_symbol.name);
-
   /* PR ld/6744:  Warn the user if they have used an ELF-only
      option hoping it will work on PE.  */
   if (link_info.export_dynamic)
     einfo (_("%P: warning: --export-dynamic is not supported for PE "
       "targets, did you mean --export-all-symbols?\n"));
+
+  after_parse_default ();
 }
 
 /* pe-dll.c directly accesses pe_data_import_dll,
Index: ld/emultempl/pep.em
===================================================================
RCS file: /cvs/src/src/ld/emultempl/pep.em,v
retrieving revision 1.27
diff -u -p -r1.27 pep.em
--- ld/emultempl/pep.em	15 May 2009 14:22:35 -0000	1.27
+++ ld/emultempl/pep.em	12 Sep 2009 06:46:08 -0000
@@ -814,27 +814,13 @@ gld_${EMULATION_NAME}_set_symbols (void)
 static void
 gld_${EMULATION_NAME}_after_parse (void)
 {
-  /* The Windows libraries are designed for the linker to treat the
-     entry point as an undefined symbol.  Otherwise, the .obj that
-     defines mainCRTStartup is brought in because it is the first
-     encountered in libc.lib and it has other symbols in it which will
-     be pulled in by the link process.  To avoid this, we act as
-     though the user specified -u with the entry point symbol.
-
-     This function is called after the linker script and command line
-     options have been read, so at this point we know the right entry
-     point.  This function is called before the input files are
-     opened, so registering the symbol as undefined will make a
-     difference.  */
-
-  if (! link_info.relocatable && entry_symbol.name != NULL)
-    ldlang_add_undef (entry_symbol.name);
-
   /* PR ld/6744:  Warn the user if they have used an ELF-only
      option hoping it will work on PE+.  */
   if (link_info.export_dynamic)
     einfo (_("%P: warning: --export-dynamic is not supported for PE+ "
       "targets, did you mean --export-all-symbols?\n"));
+
+  after_parse_default ();
 }
 
 /* pep-dll.c directly accesses pep_data_import_dll,
Index: ld/scripttempl/elf32cr16.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/elf32cr16.sc,v
retrieving revision 1.3
diff -u -p -r1.3 elf32cr16.sc
--- ld/scripttempl/elf32cr16.sc	6 Aug 2009 17:38:04 -0000	1.3
+++ ld/scripttempl/elf32cr16.sc	12 Sep 2009 06:46:10 -0000
@@ -10,14 +10,8 @@ cat <<EOF
 
 /* Example Linker Script for linking NS CR16 elf32 files. */
 
-/* The next line forces the entry point (${ENTRY} in this script)
-   to be entered in the output file as an undefined symbol.
-   It is needed in case the entry point is not called explicitly
-   (which is the usual case) AND is in an archive.  */
-
 OUTPUT_FORMAT("${OUTPUT_FORMAT}")
 OUTPUT_ARCH(${ARCH})
-${RELOCATING+EXTERN(${ENTRY})}
 ${RELOCATING+ENTRY(${ENTRY})}
 
 /* Define memory regions.  */
Index: ld/scripttempl/elf32cr16c.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/elf32cr16c.sc,v
retrieving revision 1.3
diff -u -p -r1.3 elf32cr16c.sc
--- ld/scripttempl/elf32cr16c.sc	6 Aug 2009 17:38:04 -0000	1.3
+++ ld/scripttempl/elf32cr16c.sc	12 Sep 2009 06:46:10 -0000
@@ -7,12 +7,6 @@ cat <<EOF
    elf32 files, which were compiled with either the near data
    model or the default data model.  */
 
-/* Force the entry point to be entered in the output file as
-   an undefined symbol. This is needed in case the entry point
-   (which is not called explicitly) is in an archive (which is
-   the usual case).  */
-
-${RELOCATING+EXTERN(${ENTRY})}
 ${RELOCATING+ENTRY(${ENTRY})}
 
 MEMORY
Index: ld/scripttempl/elf32crx.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/elf32crx.sc,v
retrieving revision 1.7
diff -u -p -r1.7 elf32crx.sc
--- ld/scripttempl/elf32crx.sc	6 Aug 2009 17:38:04 -0000	1.7
+++ ld/scripttempl/elf32crx.sc	12 Sep 2009 06:46:10 -0000
@@ -10,14 +10,8 @@ cat <<EOF
 
 /* Example Linker Script for linking NS CRX elf32 files. */
 
-/* The next line forces the entry point (${ENTRY} in this script)
-   to be entered in the output file as an undefined symbol.
-   It is needed in case the entry point is not called explicitly
-   (which is the usual case) AND is in an archive.  */
-
 OUTPUT_FORMAT("${OUTPUT_FORMAT}")
 OUTPUT_ARCH(${ARCH})
-${RELOCATING+EXTERN(${ENTRY})}
 ${RELOCATING+ENTRY(${ENTRY})}
 
 /* Define memory regions.  */
Index: ld/scripttempl/elf32xc16xs.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/elf32xc16xs.sc,v
retrieving revision 1.1
diff -u -p -r1.1 elf32xc16xs.sc
--- ld/scripttempl/elf32xc16xs.sc	17 Feb 2006 14:36:28 -0000	1.1
+++ ld/scripttempl/elf32xc16xs.sc	12 Sep 2009 06:46:11 -0000
@@ -1,7 +1,7 @@
 cat <<EOF
 OUTPUT_FORMAT("${OUTPUT_FORMAT}")
 OUTPUT_ARCH(${ARCH})
-ENTRY("_start")
+${RELOCATING+ENTRY ("_start")}
 MEMORY
 {
 	vectarea : o =0xc00000, l = 0x0300 

-- 
Alan Modra
Australia Development Lab, IBM


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