[8/9,gas] Introduce new section flag: SEC_ELF_OCTETS

Message ID 20191121211732.16653-9-ceggers@gmx.de
State New
Headers show
Series
  • ELF support for targets with octets_per_byte>1
Related show

Commit Message

Christian Eggers Nov. 21, 2019, 9:17 p.m.
All symbols, sizes and relocations in this sections are octets instead
of bytes. Required for DWARF debug sections as DWARF information is
organized in octets, not bytes.

	* as.h: Define SEC_OCTETS as SEC_ELF_OCTETS if OBJ_ELF.
	* dwarf2dbg.c: (dwarf2_finish): Set section flag SEC_OCTETS for
	.debug_line, .debug_info, .debug_abbrev, .debug_aranges, .debug_str
	and .debug_ranges sections.
	* write.c (maybe_generate_build_notes): Set section flag
	SEC_OCTETS for .gnu.build.attributes section.
	* frags.c (frag_now_fix): Don't divide by OCTETS_PER_BYTE if
	SEC_OCTETS is set.
	* symbols.c (resolve_symbol_value): Likewise.

Signed-off-by: Christian Eggers <ceggers@gmx.de>

---
 gas/as.h        |  7 +++++++
 gas/dwarf2dbg.c | 19 ++++++++++++-------
 gas/frags.c     |  7 ++++++-
 gas/symbols.c   | 15 +++++++++++++--
 gas/write.c     |  3 ++-
 5 files changed, 40 insertions(+), 11 deletions(-)

--
2.16.4

Patch

diff --git a/gas/as.h b/gas/as.h
index d996697bed..ecf44bd421 100644
--- a/gas/as.h
+++ b/gas/as.h
@@ -648,4 +648,11 @@  COMMON int flag_sectname_subst;
  #error "Octets per byte conflicts with its power-of-two definition!"
 #endif

+#if defined OBJ_ELF || defined OBJ_MAYBE_ELF
+/* On ELF platforms, mark debug sections with SEC_ELF_OCTETS */
+#define SEC_OCTETS (IS_ELF ? SEC_ELF_OCTETS : 0)
+#else
+#define SEC_OCTETS 0
+#endif
+
 #endif /* GAS */
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index dce96033df..001e2a16ad 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -2215,7 +2215,7 @@  dwarf2_finish (void)

   /* Create and switch to the line number section.  */
   line_seg = subseg_new (".debug_line", 0);
-  bfd_set_section_flags (line_seg, SEC_READONLY | SEC_DEBUGGING);
+  bfd_set_section_flags (line_seg, SEC_READONLY | SEC_DEBUGGING | SEC_OCTETS);

   /* For each subsection, chain the debug entries together.  */
   for (s = all_segs; s; s = s->next)
@@ -2261,11 +2261,15 @@  dwarf2_finish (void)
       aranges_seg = subseg_new (".debug_aranges", 0);
       str_seg = subseg_new (".debug_str", 0);

-      bfd_set_section_flags (info_seg, SEC_READONLY | SEC_DEBUGGING);
-      bfd_set_section_flags (abbrev_seg, SEC_READONLY | SEC_DEBUGGING);
-      bfd_set_section_flags (aranges_seg, SEC_READONLY | SEC_DEBUGGING);
-      bfd_set_section_flags (str_seg, (SEC_READONLY | SEC_DEBUGGING
-				       | SEC_MERGE | SEC_STRINGS));
+      bfd_set_section_flags (info_seg,
+			      SEC_READONLY | SEC_DEBUGGING | SEC_OCTETS);
+      bfd_set_section_flags (abbrev_seg,
+			      SEC_READONLY | SEC_DEBUGGING | SEC_OCTETS);
+      bfd_set_section_flags (aranges_seg,
+			      SEC_READONLY | SEC_DEBUGGING | SEC_OCTETS);
+      bfd_set_section_flags (str_seg,
+			      SEC_READONLY | SEC_DEBUGGING | SEC_OCTETS
+				       | SEC_MERGE | SEC_STRINGS);
       str_seg->entsize = 1;

       record_alignment (aranges_seg, ffs (2 * sizeof_address) - 1);
@@ -2275,7 +2279,8 @@  dwarf2_finish (void)
       else
 	{
 	  ranges_seg = subseg_new (".debug_ranges", 0);
-	  bfd_set_section_flags (ranges_seg, SEC_READONLY | SEC_DEBUGGING);
+	  bfd_set_section_flags (ranges_seg,
+				 SEC_READONLY | SEC_DEBUGGING | SEC_OCTETS);
 	  record_alignment (ranges_seg, ffs (2 * sizeof_address) - 1);
 	  out_debug_ranges (ranges_seg);
 	}
diff --git a/gas/frags.c b/gas/frags.c
index 2f21b9db20..f35cc80a38 100644
--- a/gas/frags.c
+++ b/gas/frags.c
@@ -395,7 +395,12 @@  frag_now_fix_octets (void)
 addressT
 frag_now_fix (void)
 {
-  return frag_now_fix_octets () / OCTETS_PER_BYTE;
+  /* Symbols whose section has SEC_ELF_OCTETS set,
+     resolve to octets instead of target bytes.  */
+  if (now_seg->flags & SEC_OCTETS)
+    return frag_now_fix_octets ();
+  else
+    return frag_now_fix_octets () / OCTETS_PER_BYTE;
 }

 void
diff --git a/gas/symbols.c b/gas/symbols.c
index cff24059e6..857a3e6c5c 100644
--- a/gas/symbols.c
+++ b/gas/symbols.c
@@ -1217,7 +1217,13 @@  resolve_symbol_value (symbolS *symp)
       if (local_symbol_resolved_p (locsym))
 	return final_val;

-      final_val += local_symbol_get_frag (locsym)->fr_address / OCTETS_PER_BYTE;
+      /* Symbols whose section has SEC_ELF_OCTETS set,
+	 resolve to octets instead of target bytes. */
+      if (locsym->lsy_section->flags & SEC_OCTETS)
+	final_val += local_symbol_get_frag (locsym)->fr_address;
+      else
+	final_val += (local_symbol_get_frag (locsym)->fr_address
+		      / OCTETS_PER_BYTE);

       if (finalize_syms)
 	{
@@ -1330,7 +1336,12 @@  resolve_symbol_value (symbolS *symp)
 	  /* Fall through.  */

 	case O_constant:
-	  final_val += symp->sy_frag->fr_address / OCTETS_PER_BYTE;
+	  /* Symbols whose section has SEC_ELF_OCTETS set,
+	     resolve to octets instead of target bytes. */
+	  if (symp->bsym->section->flags & SEC_OCTETS)
+	    final_val += symp->sy_frag->fr_address;
+	  else
+	    final_val += symp->sy_frag->fr_address / OCTETS_PER_BYTE;
 	  if (final_seg == expr_section)
 	    final_seg = absolute_section;
 	  /* Fall through.  */
diff --git a/gas/write.c b/gas/write.c
index 8f7786eb36..7e8851ebb1 100644
--- a/gas/write.c
+++ b/gas/write.c
@@ -1960,7 +1960,8 @@  maybe_generate_build_notes (void)
   /* Create a GNU Build Attribute section.  */
   sec = subseg_new (GNU_BUILD_ATTRS_SECTION_NAME, FALSE);
   elf_section_type (sec) = SHT_NOTE;
-  bfd_set_section_flags (sec, SEC_READONLY | SEC_HAS_CONTENTS | SEC_DATA);
+  bfd_set_section_flags (sec, SEC_READONLY | SEC_HAS_CONTENTS | SEC_DATA
+			 | SEC_OCTETS);
   bfd_set_section_alignment (sec, 2);

   /* Work out the size of the notes that we will create,