19990502 sourceware importbinu_ss_19990502

1 files changed, 359 insertions, 0 deletions

diff --git a/gas/frags.c b/gas/frags.c
new file mode 100644
index 0000000..240b2ee
--- /dev/null
+++ b/gas/frags.c
@@ -0,0 +1,359 @@
+/* frags.c - manage frags -
+   Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 97, 1998
+   Free Software Foundation, Inc.
+
+   This file is part of GAS, the GNU Assembler.
+
+   GAS is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   GAS is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GAS; see the file COPYING.  If not, write to the Free
+   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.  */
+
+#include "as.h"
+#include "subsegs.h"
+#include "obstack.h"
+
+extern fragS zero_address_frag;
+extern fragS bss_address_frag;
+
+/* Initialization for frag routines.  */
+void
+frag_init ()
+{
+  zero_address_frag.fr_type = rs_fill;
+  bss_address_frag.fr_type = rs_fill;
+}
+
+/* Allocate a frag on the specified obstack.
+   Call this routine from everywhere else, so that all the weird alignment
+   hackery can be done in just one place.  */
+fragS *
+frag_alloc (ob)
+     struct obstack *ob;
+{
+  fragS *ptr;
+  int oalign;
+
+  (void) obstack_alloc (ob, 0);
+  oalign = obstack_alignment_mask (ob);
+  obstack_alignment_mask (ob) = 0;
+  ptr = (fragS *) obstack_alloc (ob, SIZEOF_STRUCT_FRAG);
+  obstack_alignment_mask (ob) = oalign;
+  memset (ptr, 0, SIZEOF_STRUCT_FRAG);
+  return ptr;
+}
+
+/*
+ *			frag_grow()
+ *
+ * Try to augment current frag by nchars chars.
+ * If there is no room, close of the current frag with a ".fill 0"
+ * and begin a new frag. Unless the new frag has nchars chars available
+ * do not return. Do not set up any fields of *now_frag.
+ */
+void 
+frag_grow (nchars)
+     unsigned int nchars;
+{
+  if (obstack_room (&frchain_now->frch_obstack) < nchars)
+    {
+      unsigned int n;
+      long oldc;
+
+      frag_wane (frag_now);
+      frag_new (0);
+      oldc = frchain_now->frch_obstack.chunk_size;
+      frchain_now->frch_obstack.chunk_size = 2 * nchars + SIZEOF_STRUCT_FRAG;
+      while ((n = obstack_room (&frchain_now->frch_obstack)) < nchars)
+	{
+	  frag_wane (frag_now);
+	  frag_new (0);
+	}
+      frchain_now->frch_obstack.chunk_size = oldc;
+    }
+  if (obstack_room (&frchain_now->frch_obstack) < nchars)
+    as_fatal (_("Can't extend frag %d. chars"), nchars);
+}
+
+/*
+ *			frag_new()
+ *
+ * Call this to close off a completed frag, and start up a new (empty)
+ * frag, in the same subsegment as the old frag.
+ * [frchain_now remains the same but frag_now is updated.]
+ * Because this calculates the correct value of fr_fix by
+ * looking at the obstack 'frags', it needs to know how many
+ * characters at the end of the old frag belong to (the maximal)
+ * fr_var: the rest must belong to fr_fix.
+ * It doesn't actually set up the old frag's fr_var: you may have
+ * set fr_var == 1, but allocated 10 chars to the end of the frag:
+ * in this case you pass old_frags_var_max_size == 10.
+ *
+ * Make a new frag, initialising some components. Link new frag at end
+ * of frchain_now.
+ */
+void 
+frag_new (old_frags_var_max_size)
+     /* Number of chars (already allocated on obstack frags) in
+	variable_length part of frag. */
+     int old_frags_var_max_size;
+{
+  fragS *former_last_fragP;
+  frchainS *frchP;
+
+  assert (frchain_now->frch_last == frag_now);
+
+  /* Fix up old frag's fr_fix.  */
+  frag_now->fr_fix = frag_now_fix () - old_frags_var_max_size;
+  /* Make sure its type is valid.  */
+  assert (frag_now->fr_type != 0);
+
+  /* This will align the obstack so the next struct we allocate on it
+     will begin at a correct boundary. */
+  obstack_finish (&frchain_now->frch_obstack);
+  frchP = frchain_now;
+  know (frchP);
+  former_last_fragP = frchP->frch_last;
+  assert (former_last_fragP != 0);
+  assert (former_last_fragP == frag_now);
+  frag_now = frag_alloc (&frchP->frch_obstack);
+
+  as_where (&frag_now->fr_file, &frag_now->fr_line);
+
+  /* Generally, frag_now->points to an address rounded up to next
+     alignment.  However, characters will add to obstack frags
+     IMMEDIATELY after the struct frag, even if they are not starting
+     at an alignment address. */
+  former_last_fragP->fr_next = frag_now;
+  frchP->frch_last = frag_now;
+
+#ifndef NO_LISTING
+  {
+    extern struct list_info_struct *listing_tail;
+    frag_now->line = listing_tail;
+  }
+#endif
+
+  assert (frchain_now->frch_last == frag_now);
+
+  frag_now->fr_next = NULL;
+}				/* frag_new() */
+
+/*
+ *			frag_more()
+ *
+ * Start a new frag unless we have n more chars of room in the current frag.
+ * Close off the old frag with a .fill 0.
+ *
+ * Return the address of the 1st char to write into. Advance
+ * frag_now_growth past the new chars.
+ */
+
+char *
+frag_more (nchars)
+     int nchars;
+{
+  register char *retval;
+
+  if (now_seg == absolute_section)
+    {
+      as_bad (_("attempt to allocate data in absolute section"));
+      subseg_set (text_section, 0);
+    }
+
+  if (mri_common_symbol != NULL)
+    {
+      as_bad (_("attempt to allocate data in common section"));
+      mri_common_symbol = NULL;
+    }
+
+  frag_grow (nchars);
+  retval = obstack_next_free (&frchain_now->frch_obstack);
+  obstack_blank_fast (&frchain_now->frch_obstack, nchars);
+  return (retval);
+}				/* frag_more() */
+
+/*
+ *			frag_var()
+ *
+ * Start a new frag unless we have max_chars more chars of room in the current frag.
+ * Close off the old frag with a .fill 0.
+ *
+ * Set up a machine_dependent relaxable frag, then start a new frag.
+ * Return the address of the 1st char of the var part of the old frag
+ * to write into.
+ */
+
+char *
+frag_var (type, max_chars, var, subtype, symbol, offset, opcode)
+     relax_stateT type;
+     int max_chars;
+     int var;
+     relax_substateT subtype;
+     symbolS *symbol;
+     offsetT offset;
+     char *opcode;
+{
+  register char *retval;
+
+  frag_grow (max_chars);
+  retval = obstack_next_free (&frchain_now->frch_obstack);
+  obstack_blank_fast (&frchain_now->frch_obstack, max_chars);
+  frag_now->fr_var = var;
+  frag_now->fr_type = type;
+  frag_now->fr_subtype = subtype;
+  frag_now->fr_symbol = symbol;
+  frag_now->fr_offset = offset;
+  frag_now->fr_opcode = opcode;
+#ifdef USING_CGEN
+  frag_now->fr_cgen.insn = 0;
+  frag_now->fr_cgen.opindex = 0;
+  frag_now->fr_cgen.opinfo = 0;
+#endif
+#ifdef TC_FRAG_INIT
+  TC_FRAG_INIT (frag_now);
+#endif
+  as_where (&frag_now->fr_file, &frag_now->fr_line);
+  frag_new (max_chars);
+  return (retval);
+}
+
+/*
+ *			frag_variant()
+ *
+ * OVE: This variant of frag_var assumes that space for the tail has been
+ *      allocated by caller.
+ *      No call to frag_grow is done.
+ */
+
+char *
+frag_variant (type, max_chars, var, subtype, symbol, offset, opcode)
+     relax_stateT type;
+     int max_chars;
+     int var;
+     relax_substateT subtype;
+     symbolS *symbol;
+     offsetT offset;
+     char *opcode;
+{
+  register char *retval;
+
+  retval = obstack_next_free (&frchain_now->frch_obstack);
+  frag_now->fr_var = var;
+  frag_now->fr_type = type;
+  frag_now->fr_subtype = subtype;
+  frag_now->fr_symbol = symbol;
+  frag_now->fr_offset = offset;
+  frag_now->fr_opcode = opcode;
+#ifdef USING_CGEN
+  frag_now->fr_cgen.insn = 0;
+  frag_now->fr_cgen.opindex = 0;
+  frag_now->fr_cgen.opinfo = 0;
+#endif
+#ifdef TC_FRAG_INIT
+  TC_FRAG_INIT (frag_now);
+#endif
+  as_where (&frag_now->fr_file, &frag_now->fr_line);
+  frag_new (max_chars);
+  return (retval);
+}				/* frag_variant() */
+
+/*
+ *			frag_wane()
+ *
+ * Reduce the variable end of a frag to a harmless state.
+ */
+void 
+frag_wane (fragP)
+     register fragS *fragP;
+{
+  fragP->fr_type = rs_fill;
+  fragP->fr_offset = 0;
+  fragP->fr_var = 0;
+}
+
+/* Make an alignment frag.  The size of this frag will be adjusted to
+   force the next frag to have the appropriate alignment.  ALIGNMENT
+   is the power of two to which to align.  FILL_CHARACTER is the
+   character to use to fill in any bytes which are skipped.  MAX is
+   the maximum number of characters to skip when doing the alignment,
+   or 0 if there is no maximum.  */
+
+void 
+frag_align (alignment, fill_character, max)
+     int alignment;
+     int fill_character;
+     int max;
+{
+  if (now_seg == absolute_section)
+    {
+      addressT new_off;
+
+      new_off = ((abs_section_offset + alignment - 1)
+		 &~ ((1 << alignment) - 1));
+      if (max == 0 || new_off - abs_section_offset <= (addressT) max)
+	abs_section_offset = new_off;
+    }
+  else
+    {
+      char *p;
+
+      p = frag_var (rs_align, 1, 1, (relax_substateT) max,
+		    (symbolS *) 0, (offsetT) alignment, (char *) 0);
+      *p = fill_character;
+    }
+}
+
+/* Make an alignment frag like frag_align, but fill with a repeating
+   pattern rather than a single byte.  ALIGNMENT is the power of two
+   to which to align.  FILL_PATTERN is the fill pattern to repeat in
+   the bytes which are skipped.  N_FILL is the number of bytes in
+   FILL_PATTERN.  MAX is the maximum number of characters to skip when
+   doing the alignment, or 0 if there is no maximum.  */
+
+void 
+frag_align_pattern (alignment, fill_pattern, n_fill, max)
+     int alignment;
+     const char *fill_pattern;
+     int n_fill;
+     int max;
+{
+  char *p;
+
+  p = frag_var (rs_align, n_fill, n_fill, (relax_substateT) max,
+		(symbolS *) 0, (offsetT) alignment, (char *) 0);
+  memcpy (p, fill_pattern, n_fill);
+}
+
+addressT
+frag_now_fix ()
+{
+  if (now_seg == absolute_section)
+    return abs_section_offset;
+  return (addressT) ((char*) obstack_next_free (&frchain_now->frch_obstack)
+		     - frag_now->fr_literal);
+}
+
+void
+frag_append_1_char (datum)
+     int datum;
+{
+  if (obstack_room (&frchain_now->frch_obstack) <= 1)
+    {
+      frag_wane (frag_now);
+      frag_new (0);
+    }
+  obstack_1grow (&frchain_now->frch_obstack, datum);
+}
+
+/* end of frags.c */