Use a symbol flag bit to mark linker defined symbols
authorAlan Modra <amodra@gmail.com>
Tue, 23 Dec 2014 08:37:23 +0000 (19:07 +1030)
committerAlan Modra <amodra@gmail.com>
Tue, 23 Dec 2014 13:06:50 +0000 (23:36 +1030)
Trying to use the SEC_LINKER_CREATED section flag to determine whether
a symbol is linker defined fails to work on targets like alpha that
define special SEC_COMMON sections.  These might contain symbols that
originated in an object file.

include/
* bfdlink.h (struct bfd_link_hash_entry): Comment non_ir_ref.  Add
linker_def.
bfd/
* elflink.c (_bfd_elf_define_linkage_sym): Set linker_def.
* linker.c (_bfd_generic_link_add_one_symbol): Clear linker_def
for CDEF, DEF, DEFW, COM.
ld/
* ldexp.c (exp_fold_tree_1 <etree_provide>): Test linker_def.
ld/testsuite/
* ld-powerpc/sdabase.s,
* ld-powerpc/sdabase.t,
* ld-powerpc/sdabase.d: New test.
* ld-powerpc/sdabase2.t,
* ld-powerpc/sdabase2.d: New test.
* ld-powerpc/powerpc.exp: Run them.

14 files changed:
bfd/ChangeLog
bfd/elflink.c
bfd/linker.c
include/ChangeLog
include/bfdlink.h
ld/ChangeLog
ld/ldexp.c
ld/testsuite/ChangeLog
ld/testsuite/ld-powerpc/powerpc.exp
ld/testsuite/ld-powerpc/sdabase.d [new file with mode: 0644]
ld/testsuite/ld-powerpc/sdabase.s [new file with mode: 0644]
ld/testsuite/ld-powerpc/sdabase.t [new file with mode: 0644]
ld/testsuite/ld-powerpc/sdabase2.d [new file with mode: 0644]
ld/testsuite/ld-powerpc/sdabase2.t [new file with mode: 0644]

index 50ff01f..4bb379b 100644 (file)
@@ -1,3 +1,9 @@
+2014-12-23  Alan Modra  <amodra@gmail.com>
+
+       * elflink.c (_bfd_elf_define_linkage_sym): Set linker_def.
+       * linker.c (_bfd_generic_link_add_one_symbol): Clear linker_def
+       for CDEF, DEF, DEFW, COM.
+
 2014-12-22  Nick Clifton  <nickc@redhat.com>
 
        PR binutils/17512
index b701fa0..16421cf 100644 (file)
@@ -85,6 +85,7 @@ _bfd_elf_define_linkage_sym (bfd *abfd,
   h = (struct elf_link_hash_entry *) bh;
   h->def_regular = 1;
   h->non_elf = 0;
+  h->root.linker_def = 1;
   h->type = STT_OBJECT;
   if (ELF_ST_VISIBILITY (h->other) != STV_INTERNAL)
     h->other = (h->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN;
index abdf5b0..9223810 100644 (file)
@@ -1560,6 +1560,7 @@ _bfd_generic_link_add_one_symbol (struct bfd_link_info *info,
              h->type = bfd_link_hash_defined;
            h->u.def.section = section;
            h->u.def.value = value;
+           h->linker_def = 0;
 
            /* If we have been asked to, we act like collect2 and
               identify all functions that might be global
@@ -1659,6 +1660,7 @@ _bfd_generic_link_add_one_symbol (struct bfd_link_info *info,
            }
          else
            h->u.c.p->section = section;
+         h->linker_def = 0;
          break;
 
        case REF:
index 1114a63..d2e057b 100644 (file)
@@ -1,3 +1,8 @@
+2014-12-23  Alan Modra  <amodra@gmail.com>
+
+       * bfdlink.h (struct bfd_link_hash_entry): Comment non_ir_ref.  Add
+       linker_def.
+
 2014-12-12  Phil Muldoon  <pmuldoon@redhat.com>
            Jan Kratochvil  <jan.kratochvil@redhat.com>
            Tom Tromey  <tromey@redhat.com>
index f3181ba..48c91da 100644 (file)
@@ -91,8 +91,14 @@ struct bfd_link_hash_entry
   /* Type of this entry.  */
   ENUM_BITFIELD (bfd_link_hash_type) type : 8;
 
+  /* Symbol is referenced in a normal object file, as distict from a LTO
+     IR object file.  */
   unsigned int non_ir_ref : 1;
 
+  /* Symbol is a built-in define.  These will be overridden by PROVIDE
+     in a linker script.  */
+  unsigned int linker_def : 1;
+
   /* A union of information depending upon the type.  */
   union
     {
index f16d1d5..7f6eca2 100644 (file)
@@ -1,5 +1,9 @@
 2014-12-23  Alan Modra  <amodra@gmail.com>
 
+       * ldexp.c (exp_fold_tree_1 <etree_provide>): Test linker_def.
+
+2014-12-23  Alan Modra  <amodra@gmail.com>
+
        * ldexp.c (exp_fold_tree_1 <etree_provide>): Leave bfd_link_hash_common
        symbols alone.
 
index 8615869..b4af893 100644 (file)
@@ -1072,9 +1072,7 @@ exp_fold_tree_1 (etree_type *tree)
              if (h == NULL
                  || !(h->type == bfd_link_hash_new
                       || h->type == bfd_link_hash_undefined
-                      || (h->type == bfd_link_hash_defined
-                          && (h->u.def.section->flags
-                              & SEC_LINKER_CREATED) != 0)))
+                      || h->linker_def))
                {
                  /* Do nothing.  The symbol was never referenced, or
                     was defined in some object file.  Undefined weak
index c901bb7..cfc0284 100644 (file)
@@ -1,5 +1,14 @@
 2014-12-23  Alan Modra  <amodra@gmail.com>
 
+       * ld-powerpc/sdabase.s,
+       * ld-powerpc/sdabase.t,
+       * ld-powerpc/sdabase.d: New test.
+       * ld-powerpc/sdabase2.t,
+       * ld-powerpc/sdabase2.d: New test.
+       * ld-powerpc/powerpc.exp: Run them.
+
+2014-12-23  Alan Modra  <amodra@gmail.com>
+
        * ld-elf/endsym.s, *ld-elf/endsym.d: New test.
 
 2014-12-19  Matthew Fortune  <matthew.fortune@imgtec.com>
index 599b980..645236d 100644 (file)
@@ -289,6 +289,8 @@ if { [istarget "powerpc*-eabi*"] } {
 }
 
 run_dump_test "plt1"
+run_dump_test "sdabase"
+run_dump_test "sdabase2"
 
 run_dump_test "attr-gnu-4-00"
 run_dump_test "attr-gnu-4-01"
diff --git a/ld/testsuite/ld-powerpc/sdabase.d b/ld/testsuite/ld-powerpc/sdabase.d
new file mode 100644 (file)
index 0000000..c54f750
--- /dev/null
@@ -0,0 +1,10 @@
+#source: sdabase.s
+#as: -a32
+#ld: -melf32ppc -T sdabase.t
+#objdump: -s
+#target: powerpc*-*-*
+
+.*:     file format .*
+
+Contents of section \.sdata:
+ 0400 (00008400|00840000) (00000400|00040000) .*
diff --git a/ld/testsuite/ld-powerpc/sdabase.s b/ld/testsuite/ld-powerpc/sdabase.s
new file mode 100644 (file)
index 0000000..8c85688
--- /dev/null
@@ -0,0 +1,9 @@
+       .text
+       .globl _start
+_start:
+
+       .section .sdata,"aw",@progbits
+       .globl my_sdata
+my_sdata:
+       .dc.a   _SDA_BASE_
+       .dc.a   my_sdata
diff --git a/ld/testsuite/ld-powerpc/sdabase.t b/ld/testsuite/ld-powerpc/sdabase.t
new file mode 100644 (file)
index 0000000..2486962
--- /dev/null
@@ -0,0 +1,6 @@
+SECTIONS
+{
+  .text 0x100 : { *(.text) }
+  .sdata 0x400 : { *(.sdata) }
+  /DISCARD/ : { *(*) }
+}
diff --git a/ld/testsuite/ld-powerpc/sdabase2.d b/ld/testsuite/ld-powerpc/sdabase2.d
new file mode 100644 (file)
index 0000000..a0da6f5
--- /dev/null
@@ -0,0 +1,10 @@
+#source: sdabase.s
+#as: -a32
+#ld: -melf32ppc -T sdabase2.t
+#objdump: -s
+#target: powerpc*-*-*
+
+.*:     file format .*
+
+Contents of section \.sdata:
+ 0400 (00000400|00040000) (00000400|00040000) .*
diff --git a/ld/testsuite/ld-powerpc/sdabase2.t b/ld/testsuite/ld-powerpc/sdabase2.t
new file mode 100644 (file)
index 0000000..2a8f5d0
--- /dev/null
@@ -0,0 +1,6 @@
+SECTIONS
+{
+  .text 0x100 : { *(.text) }
+  .sdata 0x400 : { PROVIDE (_SDA_BASE_ = .); *(.sdata) }
+  /DISCARD/ : { *(*) }
+}