2009-03-05 Christophe Lyon <christophe.lyon@st.com>

[deliverable/binutils-gdb.git] / bfd / elf32-arm.c

diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index 2527e5e8425714d8dd1d96aa6242c08f64b020cd..607ba04adaa7a6c269e138d40fcb43a9adee1cf3 100644 (file)
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -2857,6 +2857,7 @@ arm_type_of_stub (struct bfd_link_info *info,
   int thumb2;
   int thumb_only;
   enum elf32_arm_stub_type stub_type = arm_stub_none;
+  int use_plt = 0;
 
   /* We don't know the actual type of destination in case it is of
      type STT_SECTION: give up.  */
@@ -2878,20 +2879,38 @@ arm_type_of_stub (struct bfd_link_info *info,
 
   r_type = ELF32_R_TYPE (rel->r_info);
 
-  /* If the call will go through a PLT entry then we do not need
-     glue.  */
+  /* Keep a simpler condition, for the sake of clarity.  */
   if (globals->splt != NULL && hash != NULL && hash->root.plt.offset != (bfd_vma) -1)
-    return stub_type;
+    {
+      use_plt = 1;
+      /* Note when dealing with PLT entries: the main PLT stub is in
+        ARM mode, so if the branch is in Thumb mode, another
+        Thumb->ARM stub will be inserted later just before the ARM
+        PLT stub. We don't take this extra distance into account
+        here, because if a long branch stub is needed, we'll add a
+        Thumb->Arm one and branch directly to the ARM PLT entry
+        because it avoids spreading offset corrections in several
+        places.  */
+    }
 
   if (r_type == R_ARM_THM_CALL)
     {
+      /* Handle cases where:
+        - this call goes too far (different Thumb/Thumb2 max
+           distance)
+        - it's a Thumb->Arm call and blx is not available. A stub is
+           needed in this case, but only if this call is not through a
+           PLT entry. Indeed, PLT stubs handle mode switching already.
+      */
       if ((!thumb2
            && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
                || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
          || (thumb2
              && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
                  || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
-         || ((st_type != STT_ARM_TFUNC) && !globals->use_blx))
+         || ((st_type != STT_ARM_TFUNC)
+             && ((r_type == R_ARM_THM_CALL) && !globals->use_blx)
+             && !use_plt))
        {
          if (st_type == STT_ARM_TFUNC)
            {
@@ -6049,9 +6068,11 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
       /* Handle relocations which should use the PLT entry.  ABS32/REL32
         will use the symbol's value, which may point to a PLT entry, but we
         don't need to handle that here.  If we created a PLT entry, all
-        branches in this object should go to it.  */
+        branches in this object should go to it, except if the PLT is too
+        far away, in which case a long branch stub should be inserted.  */
       if ((r_type != R_ARM_ABS32 && r_type != R_ARM_REL32
-           && r_type != R_ARM_ABS32_NOI && r_type != R_ARM_REL32_NOI)
+           && r_type != R_ARM_ABS32_NOI && r_type != R_ARM_REL32_NOI
+          && r_type != R_ARM_CALL)
          && h != NULL
          && splt != NULL
          && h->plt.offset != (bfd_vma) -1)
@@ -6208,11 +6229,6 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
          bfd_signed_vma branch_offset;
          struct elf32_arm_stub_hash_entry *stub_entry = NULL;
 
-         from = (input_section->output_section->vma
-                 + input_section->output_offset
-                 + rel->r_offset);
-         branch_offset = (bfd_signed_vma)(value - from);
-
          if (r_type == R_ARM_XPC25)
            {
              /* Check for Arm calling Arm function.  */
@@ -6244,6 +6260,21 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
             destination is too far or we are changing mode.  */
          if (r_type == R_ARM_CALL)
            {
+             /* If the call goes through a PLT entry, make sure to
+                check distance to the right destination address.  */
+             if (h != NULL && splt != NULL && h->plt.offset != (bfd_vma) -1)
+               {
+                 value = (splt->output_section->vma
+                          + splt->output_offset
+                          + h->plt.offset);
+                 *unresolved_reloc_p = FALSE;
+               }
+
+             from = (input_section->output_section->vma
+                     + input_section->output_offset
+                     + rel->r_offset);
+             branch_offset = (bfd_signed_vma)(value - from);
+
              if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
                  || branch_offset < ARM_MAX_BWD_BRANCH_OFFSET
                  || sym_flags == STT_ARM_TFUNC)