Update objcopy's --section-alignment option so that it sets the alignment flag on PE sections. Add a check for aligned sections not matching their VMAs.

1 files changed, 101 insertions, 9 deletions

diff --git a/binutils/objcopy.c b/binutils/objcopy.c
index a8e0f15..77ab908 100644
--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -4100,6 +4100,50 @@ setup_bfd_headers (bfd *ibfd, bfd *obfd)
   return;
 }
 
+static inline signed int
+power_of_two (bfd_vma val)
+{
+  signed int result = 0;
+
+  if (val == 0)
+    return 0;
+
+  while ((val & 1) == 0)
+    {
+      val >>= 1;
+      ++result;
+    }
+
+  if (val != 1)
+    /* Number has more than one 1, i.e. wasn't a power of 2.  */
+    return -1;
+
+  return result;
+}
+
+static unsigned int
+image_scn_align (unsigned int alignment)
+{
+  switch (alignment)
+    {
+    case 8192: return IMAGE_SCN_ALIGN_8192BYTES;
+    case 4096: return IMAGE_SCN_ALIGN_4096BYTES;
+    case 2048: return IMAGE_SCN_ALIGN_2048BYTES;
+    case 1024: return IMAGE_SCN_ALIGN_1024BYTES;
+    case  512: return IMAGE_SCN_ALIGN_512BYTES;
+    case  256: return IMAGE_SCN_ALIGN_256BYTES;
+    case  128: return IMAGE_SCN_ALIGN_128BYTES;
+    case   64: return IMAGE_SCN_ALIGN_64BYTES;
+    case   32: return IMAGE_SCN_ALIGN_32BYTES;
+    case   16: return IMAGE_SCN_ALIGN_16BYTES;
+    case    8: return IMAGE_SCN_ALIGN_8BYTES;
+    case    4: return IMAGE_SCN_ALIGN_4BYTES;
+    case    2: return IMAGE_SCN_ALIGN_2BYTES;
+    case    1: return IMAGE_SCN_ALIGN_1BYTES;
+    default: return 0;
+    }
+}
+
 /* Create a section in OBFD with the same
    name and attributes as ISECTION in IBFD.  */
 
@@ -4224,6 +4268,8 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
   if (!bfd_set_section_size (osection, size))
     err = _("failed to set size");
 
+  bool vma_set_by_user = false;
+
   vma = bfd_section_vma (isection);
   p = find_section_list (bfd_section_name (isection), false,
 			 SECTION_CONTEXT_ALTER_VMA | SECTION_CONTEXT_SET_VMA);
@@ -4233,6 +4279,7 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
 	vma = p->vma_val;
       else
 	vma += p->vma_val;
+      vma_set_by_user = true;
     }
   else
     vma += change_section_address;
@@ -4240,6 +4287,8 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
   if (!bfd_set_section_vma (osection, vma))
     err = _("failed to set vma");
 
+  bool lma_set_by_user = false;
+
   lma = isection->lma;
   p = find_section_list (bfd_section_name (isection), false,
 			 SECTION_CONTEXT_ALTER_LMA | SECTION_CONTEXT_SET_LMA);
@@ -4249,6 +4298,7 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
 	lma += p->lma_val;
       else
 	lma = p->lma_val;
+      lma_set_by_user = true;
     }
   else
     lma += change_section_address;
@@ -4259,6 +4309,24 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
 			 SECTION_CONTEXT_SET_ALIGNMENT);
   if (p != NULL)
     alignment = p->alignment;
+  else if (pe_section_alignment != (bfd_vma) -1
+	   && bfd_get_flavour (obfd) == bfd_target_coff_flavour)
+    {
+      alignment = power_of_two (pe_section_alignment);
+
+      if (coff_section_data (ibfd, isection))
+	{
+	  struct pei_section_tdata * pei_data = pei_section_data (ibfd, isection);
+
+	  if (pei_data != NULL)
+	    {
+	      /* Set the alignment flag of the input section, which will
+		 be copied to the output section later on.  */
+	      pei_data->pe_flags &= ~IMAGE_SCN_ALIGN_POWER_BIT_MASK;
+	      pei_data->pe_flags |= image_scn_align (pe_section_alignment);
+	    }
+	}
+    }
   else
     alignment = bfd_section_alignment (isection);
 
@@ -4267,6 +4335,32 @@ setup_section (bfd *ibfd, sec_ptr isection, void *obfdarg)
   if (!bfd_set_section_alignment (osection, alignment))
     err = _("failed to set alignment");
 
+  /* If the output section's VMA is not aligned
+     and the alignment has changed
+     and the VMA was not set by the user
+     and the section does not have relocations associated with it
+     then warn the user.  */
+  if (osection->vma & ((1 << alignment) - 1)
+      && alignment != bfd_section_alignment (isection)
+      && change_section_address == 0
+      && ! vma_set_by_user
+      && bfd_get_reloc_upper_bound (ibfd, isection) < 1)
+    {
+      non_fatal (_("output section %s's alignment does not match its VMA"), name);
+    }
+
+  /* Similar check for a non-aligned LMA.
+     FIXME: Since this is only an LMA, maybe it does not matter if
+     it is not aligned ?  */
+  if (osection->lma & ((1 << alignment) - 1)
+      && alignment != bfd_section_alignment (isection)
+      && change_section_address == 0
+      && ! lma_set_by_user
+      && bfd_get_reloc_upper_bound (ibfd, isection) < 1)
+    {
+      non_fatal (_("output section %s's alignment does not match its LMA"), name);
+    }
+
   /* Copy merge entity size.  */
   osection->entsize = isection->entsize;
 
@@ -5713,15 +5807,8 @@ copy_main (int argc, char *argv[])
 	      fatal (_("bad format for --set-section-alignment: numeric argument needed"));
 
 	    /* Convert integer alignment into a power-of-two alignment.  */
-	    palign = 0;
-	    while ((align & 1) == 0)
-	      {
-	    	align >>= 1;
-	    	++palign;
-	      }
-
-	    if (align != 1)
-	      /* Number has more than on 1, i.e. wasn't a power of 2.  */
+	    palign = power_of_two (align);
+	    if (palign == -1)
 	      fatal (_("bad format for --set-section-alignment: alignment is not a power of two"));
 
 	    /* Add the alignment setting to the section list.  */
@@ -5938,6 +6025,11 @@ copy_main (int argc, char *argv[])
 	case OPTION_PE_SECTION_ALIGNMENT:
 	  pe_section_alignment = parse_vma (optarg,
 					    "--section-alignment");
+	  if (power_of_two (pe_section_alignment) == -1)
+	    {
+	      non_fatal (_("--section-alignment argument is not a power of two: %s - ignoring"), optarg);
+	      pe_section_alignment = (bfd_vma) -1;
+	    }
 	  break;
 
 	case OPTION_SUBSYSTEM: