RE: ARC port broken reloc processing

[Cupertino Miranda <Cupertino dot Miranda at synopsys dot com>]

Strange, I did test it by applying the patch from Andrew and running dejagnu with it. :(
Thanks for the fix. I will validate it with the full toolchain to make sure nothing got broken.

-----Original Message-----
From: Alan Modra [mailto:amodra@gmail.com] 
Sent: Tuesday, December 01, 2015 4:12 AM
To: Cupertino Miranda
Cc: Andrew Burgess; binutils@sourceware.org; Claudiu Zissulescu
Subject: Re: ARC port broken reloc processing

On Tue, Dec 01, 2015 at 11:34:45AM +1030, Alan Modra wrote:
> On Mon, Nov 30, 2015 at 11:57:32AM +0000, Cupertino Miranda wrote:
> > I believe in this way we set the mask to a correct value for all the relocation types, without possibly introducing inconsistencies (repetitions) in the reloc definition.
> > Nevertheless, the generic relocation patching cannot be used to fix relocations, as FORMULA would not be applied.
> 
> Applied.  Your patch will fix the relocs used in debug sections, but

Except it didn't fix the testcase, due to nothing calling arc_elf_howto_init.  Next time, please test patches before posting.

	* elf32-arc.c (ARC_ELF_HOWTO): Delete.
	(arc_elf_howto): New function.
	(bfd_elf32_bfd_reloc_type_lookup): Use it in place of existing
	init code.
	(bfd_elf32_bfd_reloc_name_lookup): Use arc_elf_howto.
	(arc_info_to_howto_rel, elf_arc_relocate_section): Likwise.
	(elf_arc_check_relocs): Likewise.

diff --git a/bfd/elf32-arc.c b/bfd/elf32-arc.c index c02db9d..bc63991 100644
--- a/bfd/elf32-arc.c
+++ b/bfd/elf32-arc.c
@@ -246,8 +246,13 @@ const int howto_table_lookup[] =  };  #undef ARC_RELOC_HOWTO
 
-#define ARC_ELF_HOWTO(r_type) \
-  (&elf_arc_howto_table[r_type])
+static reloc_howto_type *
+arc_elf_howto (unsigned int r_type)
+{
+  if (elf_arc_howto_table[R_ARC_32].dst_mask == 0)
+    arc_elf_howto_init ();
+  return &elf_arc_howto_table[r_type];
+}
 
 /* Map BFD reloc types to ARC ELF reloc types.  */
 
@@ -275,18 +280,11 @@ bfd_elf32_bfd_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
 				 bfd_reloc_code_real_type code)
 {
   unsigned int i;
-  static int fully_initialized = FALSE;
-
-  if (fully_initialized == FALSE)
-    {
-      arc_elf_howto_init ();
-      fully_initialized = TRUE; /* TODO: CHECK THIS IF IT STOPS WORKING.  */
-    }
 
   for (i = ARRAY_SIZE (arc_reloc_map); i--;)
     {
       if (arc_reloc_map[i].bfd_reloc_val == code)
-	return elf_arc_howto_table + arc_reloc_map[i].elf_reloc_val;
+	return arc_elf_howto (arc_reloc_map[i].elf_reloc_val);
     }
 
   return NULL;
@@ -300,7 +298,7 @@ bfd_elf32_bfd_reloc_name_lookup (bfd * abfd ATTRIBUTE_UNUSED, const char *r_name
   for (i = 0; i < ARRAY_SIZE (elf_arc_howto_table); i++)
     if (elf_arc_howto_table[i].name != NULL
 	&& strcasecmp (elf_arc_howto_table[i].name, r_name) == 0)
-      return elf_arc_howto_table + i;
+      return arc_elf_howto (i);
 
   return NULL;
 }
@@ -316,7 +314,7 @@ arc_info_to_howto_rel (bfd * abfd ATTRIBUTE_UNUSED,
 
   r_type = ELF32_R_TYPE (dst->r_info);
   BFD_ASSERT (r_type < (unsigned int) R_ARC_max);
-  cache_ptr->howto = &elf_arc_howto_table[r_type];
+  cache_ptr->howto = arc_elf_howto (r_type);
 }
 
 /* Set the right machine number for an ARC ELF file.  */
@@ -743,7 +741,7 @@ elf_arc_relocate_section (bfd *                   output_bfd,
 	  bfd_set_error (bfd_error_bad_value);
 	  return FALSE;
 	}
-      howto = &elf_arc_howto_table[r_type];
+      howto = arc_elf_howto (r_type);
 
       reloc_data.input_section = input_section;
       reloc_data.howto = howto;
@@ -960,7 +958,7 @@ elf_arc_check_relocs (bfd *                      abfd,
 	  bfd_set_error (bfd_error_bad_value);
 	  return FALSE;
 	}
-      howto = &elf_arc_howto_table[r_type];
+      howto = arc_elf_howto (r_type);
 
       /* Load symbol information.  */
       r_symndx = ELF32_R_SYM (rel->r_info);

--
Alan Modra
Australia Development Lab, IBM