PR26103, Assertion failure with symbols defined in link-once sections

	PR 26103
	* elflink.c (elf_link_add_archive_symbols): Exclude undefined
	symbols that were defined in discarded sections.
	* cofflink.c (coff_link_check_archive_element): Likewise.
	(coff_link_add_symbols): Set indx to -3 for symbols defined in
	discarded sections.
	(_bfd_coff_write_global_sym): Don't emit such symbols.
	libcoff-in.h (struct coff_link_hash_entry): Update indx comment.
	libcoff.h: Regenerate.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 6159d3aea3fb5aa3430b87777ac0af1ef35cf7f5..fe04699b45ffa26610c3969db4bdfadd016d1f35 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,15 @@
+2020-06-15  Alan Modra  <amodra@gmail.com>
+
+       PR 26103
+       * elflink.c (elf_link_add_archive_symbols): Exclude undefined
+       symbols that were defined in discarded sections.
+       * cofflink.c (coff_link_check_archive_element): Likewise.
+       (coff_link_add_symbols): Set indx to -3 for symbols defined in
+       discarded sections.
+       (_bfd_coff_write_global_sym): Don't emit such symbols.
+       libcoff-in.h (struct coff_link_hash_entry): Update indx comment.
+       libcoff.h: Regenerate.
+
 2020-06-11  Alan Modra  <amodra@gmail.com>
 
        PR 26107

diff --git a/bfd/cofflink.c b/bfd/cofflink.c
index 27ac20e80da814065c61f250c0eac5072e7615f5..63bdcde115deae70f52d4eb543ab1170d2c49d81 100644 (file)
--- a/bfd/cofflink.c
+++ b/bfd/cofflink.c
@@ -212,6 +212,12 @@ coff_link_check_archive_element (bfd *abfd,
   if (h->type != bfd_link_hash_undefined)
     return TRUE;
 
+  /* If the archive element has already been loaded then one
+     of the symbols defined by that element might have been
+     made undefined due to being in a discarded section.  */
+  if (((struct coff_link_hash_entry *) h)->indx == -3)
+    return TRUE;
+
   /* PR 22369 - Skip non COFF objects in the archive.  */
   if (! bfd_family_coff (abfd))
     return TRUE;
@@ -286,6 +292,7 @@ coff_link_add_symbols (bfd *abfd,
          asection *section;
          bfd_vma value;
          bfd_boolean addit;
+         bfd_boolean discarded = FALSE;
 
          /* This symbol is externally visible.  */
 
@@ -311,7 +318,10 @@ coff_link_add_symbols (bfd *abfd,
              flags = BSF_EXPORT | BSF_GLOBAL;
              section = coff_section_from_bfd_index (abfd, sym.n_scnum);
              if (discarded_section (section))
-               section = bfd_und_section_ptr;
+               {
+                 discarded = TRUE;
+                 section = bfd_und_section_ptr;
+               }
              else if (! obj_pe (abfd))
                value -= section->vma;
              break;
@@ -408,6 +418,9 @@ coff_link_add_symbols (bfd *abfd,
                      (const char *) NULL, copy, FALSE,
                      (struct bfd_link_hash_entry **) sym_hash)))
                goto error_return;
+
+             if (discarded)
+               (*sym_hash)->indx = -3;
            }
 
          if (obj_pe (abfd) && (flags & BSF_SECTION_SYM) != 0)
@@ -2567,6 +2580,9 @@ _bfd_coff_write_global_sym (struct bfd_hash_entry *bh, void *data)
       return FALSE;
 
     case bfd_link_hash_undefined:
+      if (h->indx == -3)
+       return TRUE;
+      /* Fall through.  */
     case bfd_link_hash_undefweak:
       isym.n_scnum = N_UNDEF;
       isym.n_value = 0;

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 3e56a297f69833ca5c12df61e9fd7d721d33fb8d..ac00f2984e91c5e384acf0f044861e3b711fc053 100644 (file)
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -5813,7 +5813,15 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
          if (h == NULL)
            continue;
 
-         if (h->root.type == bfd_link_hash_common)
+         if (h->root.type == bfd_link_hash_undefined)
+           {
+             /* If the archive element has already been loaded then one
+                of the symbols defined by that element might have been
+                made undefined due to being in a discarded section.  */
+             if (h->indx == -3)
+               continue;
+           }
+         else if (h->root.type == bfd_link_hash_common)
            {
              /* We currently have a common symbol.  The archive map contains
                 a reference to this symbol, so we may want to include it.  We
@@ -5830,7 +5838,7 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
              if (! elf_link_is_defined_archive_symbol (abfd, symdef))
                continue;
            }
-         else if (h->root.type != bfd_link_hash_undefined)
+         else
            {
              if (h->root.type != bfd_link_hash_undefweak)
                /* Symbol must be defined.  Don't check it again.  */

diff --git a/bfd/libcoff-in.h b/bfd/libcoff-in.h
index 3f0227c4acf8d571e412ab4068c333dbac97770b..b7fcea30bb4754d72bea70206fd7f8218e57317f 100644 (file)
--- a/bfd/libcoff-in.h
+++ b/bfd/libcoff-in.h
@@ -243,8 +243,9 @@ struct coff_link_hash_entry
 {
   struct bfd_link_hash_entry root;
 
-  /* Symbol index in output file.  Set to -1 initially.  Set to -2 if
-     there is a reloc against this symbol.  */
+  /* Symbol index in output file.  This is initialized to -1.  It is
+     set to -2 if the symbol is used by a reloc.  It is set to -3 if
+     this symbol is defined in a discarded section.  */
   long indx;
 
   /* Symbol type.  */

diff --git a/bfd/libcoff.h b/bfd/libcoff.h
index d7e0548bc504b5a6af5177c608f1cc830f148f89..df32c8604ec090b373df036b17e719d8acf4c934 100644 (file)
--- a/bfd/libcoff.h
+++ b/bfd/libcoff.h
@@ -247,8 +247,9 @@ struct coff_link_hash_entry
 {
   struct bfd_link_hash_entry root;
 
-  /* Symbol index in output file.  Set to -1 initially.  Set to -2 if
-     there is a reloc against this symbol.  */
+  /* Symbol index in output file.  This is initialized to -1.  It is
+     set to -2 if the symbol is used by a reloc.  It is set to -3 if
+     this symbol is defined in a discarded section.  */
   long indx;
 
   /* Symbol type.  */