Create a .scommon section for each input BFD so the linker has

something to attach small common symbols to.  Then avoid writing out
the (empty) .scommon section for the output BFD.

Tue Feb  2 11:41:06 1993  Ian Lance Taylor  (ian@cygnus.com)

	* coff-mips.c: Completed support for linker and binutils.

1 files changed, 83 insertions, 20 deletions

diff --git a/bfd/coff-mips.c b/bfd/coff-mips.c
index 082f6ba..bbd7b9e 100644
--- a/bfd/coff-mips.c
+++ b/bfd/coff-mips.c
@@ -122,6 +122,12 @@ typedef struct ecoff_symbol_struct
 /* The page boundary used to align sections in the executable file.  */
 #define PAGE_SIZE 0x2000
 
+/* The linker needs a section to hold small common variables while
+   linking.  There is no convenient way to create it when the linker
+   needs it, so we always create one for each BFD.  We then avoid
+   writing it out.  */
+#define SCOMMON ".scommon"
+
 /* MIPS ECOFF has COFF sections, but the debugging information is
    stored in a completely different format.  This files uses the some
    of the swapping routines from coffswap.h, and some of the generic
@@ -215,6 +221,10 @@ DEFUN (ecoff_mkobject, (abfd),
       return false;
     }
 
+  /* Always create a .scommon section for every BFD.  This is a hack so
+     that the linker has something to attach scSCommon symbols to.  */
+  bfd_make_section (abfd, SCOMMON);
+
   return true;
 }
 
@@ -242,7 +252,7 @@ ecoff_mkobject_hook (abfd, filehdr, aouthdr)
 
       ecoff->gp = internal_a->gp_value;
       ecoff->gprmask = internal_a->gprmask;
-      for (i = 0; i < 3; i++)
+      for (i = 0; i < 4; i++)
 	ecoff->cprmask[i] = internal_a->cprmask[i];
     }
 
@@ -661,18 +671,27 @@ DEFUN (ecoff_set_symbol_info, (abfd, ecoff_sym, asym, ext),
       asym->flags = BSF_DEBUGGING;
       break;
     case scCommon:
-      asym->section = &bfd_com_section;
-      break;
+      /* FIXME: We should take a -G argument, which gives the maximum
+	 size of objects to be put in the small common section.  Until
+	 we do, we put objects of sizes up to 8 in the small common
+	 section.  The assembler should do this for us, but the native
+	 assembler seems to get confused.  */
+      if (asym->value > 8)
+	{
+	  asym->section = &bfd_com_section;
+	  break;
+	}
+      /* Fall through.  */
     case scSCommon:
       if (ecoff_scom_section.name == NULL)
 	{
 	  /* Initialize the small common section.  */
-	  ecoff_scom_section.name = "*SCOM*";
+	  ecoff_scom_section.name = SCOMMON;
 	  ecoff_scom_section.flags = SEC_IS_COMMON;
 	  ecoff_scom_section.output_section = &ecoff_scom_section;
 	  ecoff_scom_section.symbol = &ecoff_scom_symbol;
 	  ecoff_scom_section.symbol_ptr_ptr = &ecoff_scom_symbol_ptr;
-	  ecoff_scom_symbol.name = "*SCOM*";
+	  ecoff_scom_symbol.name = SCOMMON;
 	  ecoff_scom_symbol.flags = BSF_SECTION_SYM;
 	  ecoff_scom_symbol.section = &ecoff_scom_section;
 	  ecoff_scom_symbol_ptr = &ecoff_scom_symbol;
@@ -2337,10 +2356,11 @@ DEFUN (ecoff_add_string, (output_bfd, fdr, string, external),
 /* Accumulate the debugging information from an input section.  */
 
 static boolean
-DEFUN (ecoff_get_debug, (output_bfd, seclet, section),
+DEFUN (ecoff_get_debug, (output_bfd, seclet, section, relocateable),
        bfd *output_bfd AND
        bfd_seclet_type *seclet AND
-       asection *section)
+       asection *section AND
+       boolean relocateable)
 {
   bfd *input_bfd;
   HDRR *output_symhdr;
@@ -2410,7 +2430,14 @@ DEFUN (ecoff_get_debug, (output_bfd, seclet, section),
 					       &fdr,
 					       (*sym_ptr)->name,
 					       false);
-	  internal_sym.value = (*sym_ptr)->value;
+
+	  if (bfd_is_com_section ((*sym_ptr)->section)
+	      || (*sym_ptr)->section == &bfd_und_section)
+	    internal_sym.value = (*sym_ptr)->value;
+	  else
+	    internal_sym.value = ((*sym_ptr)->value
+				  + (*sym_ptr)->section->output_offset
+				  + (*sym_ptr)->section->output_section->vma);
 	  internal_sym.st = stNil;
 	  internal_sym.sc = scUndefined;
 	  internal_sym.index = indexNil;
@@ -2461,6 +2488,17 @@ DEFUN (ecoff_get_debug, (output_bfd, seclet, section),
 	  SYMR sym;
 
 	  ecoff_swap_sym_in (input_bfd, esym_ptr->native.lnative, &sym);
+
+	  /* If we're producing an executable, move common symbols
+	     into bss.  */
+	  if (relocateable == false)
+	    {
+	      if (sym.sc == scCommon)
+		sym.sc = scBss;
+	      else if (sym.sc == scSCommon)
+		sym.sc = scSBss;
+	    }
+
 	  if (! bfd_is_com_section (esym_ptr->symbol.section)
 	      && (esym_ptr->symbol.flags & BSF_DEBUGGING) == 0
 	      && esym_ptr->symbol.section != &bfd_und_section)
@@ -2638,7 +2676,7 @@ DEFUN (ecoff_get_debug, (output_bfd, seclet, section),
     int i;
 
     output_ecoff->gprmask |= input_ecoff->gprmask;
-    for (i = 0; i < 3; i++)
+    for (i = 0; i < 4; i++)
       output_ecoff->cprmask[i] |= input_ecoff->cprmask[i];
   }
 
@@ -2830,7 +2868,7 @@ DEFUN (ecoff_bfd_seclet_link, (abfd, data, relocateable),
 	    {
 	      if (p->type == bfd_indirect_seclet)
 		{
-		  if (ecoff_get_debug (abfd, p, o) == false)
+		  if (ecoff_get_debug (abfd, p, o, relocateable) == false)
 		    return false;
 		}
 	    }
@@ -2883,6 +2921,16 @@ DEFUN (ecoff_bfd_seclet_link, (abfd, data, relocateable),
 		abort ();
 	      ecoff_swap_ext_in (abfd, ecoff_sym_ptr->native.enative, &esym);
 
+	      /* If we're producing an executable, move common symbols
+		 into bss.  */
+	      if (relocateable == false)
+		{
+		  if (esym.asym.sc == scCommon)
+		    esym.asym.sc = scBss;
+		  else if (esym.asym.sc == scSCommon)
+		    esym.asym.sc = scSBss;
+		}
+
 	      /* Adjust the FDR index for the symbol by that used for
 		 the input BFD.  */
 	      esym.ifd += ecoff_data (bfd_asymbol_bfd (sym_ptr))->ifdbase;
@@ -2931,6 +2979,17 @@ DEFUN (ecoff_set_arch_mach, (abfd, arch, machine),
   return arch == bfd_arch_mips;
 }
 
+/* Get the size of the section headers.  We do not output the .scommon
+   section which we created in ecoff_mkobject.  */
+
+static int
+ecoff_sizeof_headers (abfd, reloc)
+     bfd *abfd;
+     boolean reloc;
+{
+  return FILHSZ + AOUTSZ + (abfd->section_count - 1) * SCNHSZ;
+}
+
 /* Calculate the file position for each section, and set
    reloc_filepos.  */
 
@@ -2943,15 +3002,10 @@ DEFUN (ecoff_compute_section_file_positions, (abfd),
   file_ptr old_sofar;
   boolean first_data;
 
-  sofar = FILHSZ;
-
   if (bfd_get_start_address (abfd)) 
     abfd->flags |= EXEC_P;
 
-  /* Unlike normal COFF, ECOFF always use the ``optional'' header.  */
-  sofar += AOUTSZ;
-
-  sofar += abfd->section_count * SCNHSZ;
+  sofar = ecoff_sizeof_headers (abfd, false);
 
   first_data = true;
   for (current = abfd->sections;
@@ -2959,7 +3013,8 @@ DEFUN (ecoff_compute_section_file_positions, (abfd),
        current = current->next)
     {
       /* Only deal with sections which have contents */
-      if (! (current->flags & SEC_HAS_CONTENTS))
+      if (! (current->flags & SEC_HAS_CONTENTS)
+	  || strcmp (current->name, SCOMMON) == 0)
 	continue;
 
       /* On Ultrix, the data sections in an executable file must be
@@ -3051,6 +3106,8 @@ DEFUN (ecoff_write_object_contents, (abfd),
        current != (asection *)NULL; 
        current = current->next) 
     {
+      if (strcmp (current->name, SCOMMON) == 0)
+	continue;
       current->target_index = count;
       ++count;
       if (current->reloc_count != 0)
@@ -3076,7 +3133,7 @@ DEFUN (ecoff_write_object_contents, (abfd),
 
   ecoff_data (abfd)->sym_filepos = sym_base;
 
-  text_size = FILHSZ + AOUTSZ + abfd->section_count * SCNHSZ;
+  text_size = ecoff_sizeof_headers (abfd, false);
   text_start = 0;
   data_size = 0;
   data_start = 0;
@@ -3094,6 +3151,13 @@ DEFUN (ecoff_write_object_contents, (abfd),
       struct internal_scnhdr section;
       bfd_vma vma;
 
+      if (strcmp (current->name, SCOMMON) == 0)
+	{
+	  BFD_ASSERT (bfd_get_section_size_before_reloc (current) == 0
+		      && current->reloc_count == 0);
+	  continue;
+	}
+
       ++internal_f.f_nscns;
 
       strncpy (section.s_name, current->name, sizeof section.s_name);
@@ -3230,7 +3294,7 @@ DEFUN (ecoff_write_object_contents, (abfd),
   internal_a.gp_value = ecoff_data (abfd)->gp;
 
   internal_a.gprmask = ecoff_data (abfd)->gprmask;
-  for (i = 0; i < 3; i++)
+  for (i = 0; i < 4; i++)
     internal_a.cprmask[i] = ecoff_data (abfd)->cprmask[i];
 
   /* Write out the file header and the optional header.  */
@@ -3841,7 +3905,6 @@ static CONST bfd_coff_backend_data bfd_ecoff_std_swap_table = {
 #define	ecoff_get_section_contents	bfd_generic_get_section_contents
 #define ecoff_get_reloc_upper_bound	coff_get_reloc_upper_bound
 #define	ecoff_close_and_cleanup		bfd_generic_close_and_cleanup
-#define ecoff_sizeof_headers		coff_sizeof_headers
 #define ecoff_bfd_debug_info_start	bfd_void
 #define ecoff_bfd_debug_info_end	bfd_void
 #define ecoff_bfd_debug_info_accumulate	\