/* frags.c - manage frags -
- Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 97, 1998
+ Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+ 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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)
+ the Free Software Foundation; either version 3, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
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. */
+ Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
+ 02110-1301, USA. */
#include "as.h"
#include "subsegs.h"
extern fragS bss_address_frag;
\f
/* Initialization for frag routines. */
+
void
-frag_init ()
+frag_init (void)
{
zero_address_frag.fr_type = rs_fill;
bss_address_frag.fr_type = rs_fill;
}
\f
+/* Check that we're not trying to assemble into a section that can't
+ allocate frags (currently, this is only possible in the absolute
+ section), or into an mri common. */
+
+static void
+frag_alloc_check (const struct obstack *ob)
+{
+ if (ob->chunk_size == 0)
+ {
+ 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;
+ }
+}
+
/* 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;
+frag_alloc (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);
+ ptr = obstack_alloc (ob, SIZEOF_STRUCT_FRAG);
obstack_alignment_mask (ob) = oalign;
memset (ptr, 0, SIZEOF_STRUCT_FRAG);
return ptr;
}
\f
-/*
- * 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;
+/* 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 (unsigned int nchars)
{
if (obstack_room (&frchain_now->frch_obstack) < nchars)
{
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);
- }
+ /* Try to allocate a bit more than needed right now. But don't do
+ this if we would waste too much memory. Especially necessary
+ for extremely big (like 2GB initialized) frags. */
+ if (nchars < 0x10000)
+ frchain_now->frch_obstack.chunk_size = 2 * nchars;
+ else
+ frchain_now->frch_obstack.chunk_size = nchars + 0x10000;
+ frchain_now->frch_obstack.chunk_size += SIZEOF_STRUCT_FRAG;
+ if (frchain_now->frch_obstack.chunk_size > 0)
+ while ((n = obstack_room (&frchain_now->frch_obstack)) < nchars
+ && (unsigned long) frchain_now->frch_obstack.chunk_size > 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);
+ as_fatal (_("can't extend frag %u chars"), nchars);
}
\f
-/*
- * 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;
+/* 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
+ variable part; 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.
+ In fact, you may use fr_var for something totally unrelated to the
+ size of the variable part of the frag; None of the generic frag
+ handling code makes use of fr_var.
+
+ Make a new frag, initialising some components. Link new frag at end
+ of frchain_now. */
+
+void
+frag_new (int old_frags_var_max_size
+ /* Number of chars (already allocated on obstack frags) in
+ variable_length part of frag. */)
{
fragS *former_last_fragP;
frchainS *frchP;
- assert (frchain_now->frch_last == frag_now);
+ gas_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;
+ frag_now->fr_fix = frag_now_fix_octets () - old_frags_var_max_size;
/* Make sure its type is valid. */
- assert (frag_now->fr_type != 0);
+ gas_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. */
+ 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);
+ gas_assert (former_last_fragP != 0);
+ gas_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. */
+ at an alignment address. */
former_last_fragP->fr_next = frag_now;
frchP->frch_last = frag_now;
}
#endif
- assert (frchain_now->frch_last == frag_now);
+ gas_assert (frchain_now->frch_last == frag_now);
frag_now->fr_next = NULL;
-} /* frag_new() */
+}
\f
-/*
- * 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.
- */
+/* 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;
+frag_more (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_alloc_check (&frchain_now->frch_obstack);
frag_grow (nchars);
retval = obstack_next_free (&frchain_now->frch_obstack);
obstack_blank_fast (&frchain_now->frch_obstack, nchars);
return (retval);
-} /* frag_more() */
+}
\f
-/*
- * 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.
- */
+/* 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;
+frag_var (relax_stateT type, int max_chars, int var, relax_substateT subtype,
+ symbolS *symbol, offsetT offset, char *opcode)
{
register char *retval;
return (retval);
}
\f
-/*
- * 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.
- */
+/* 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;
+frag_variant (relax_stateT type, int max_chars, int var,
+ relax_substateT subtype, symbolS *symbol, offsetT offset,
+ char *opcode)
{
register char *retval;
as_where (&frag_now->fr_file, &frag_now->fr_line);
frag_new (max_chars);
return (retval);
-} /* frag_variant() */
+}
\f
-/*
- * frag_wane()
- *
- * Reduce the variable end of a frag to a harmless state.
- */
-void
-frag_wane (fragP)
- register fragS *fragP;
+/* Reduce the variable end of a frag to a harmless state. */
+
+void
+frag_wane (register fragS *fragP)
{
fragP->fr_type = rs_fill;
fragP->fr_offset = 0;
fragP->fr_var = 0;
}
\f
+/* Return the number of bytes by which the current frag can be grown. */
+
+int
+frag_room (void)
+{
+ return obstack_room (&frchain_now->frch_obstack);
+}
+\f
/* 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
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;
+void
+frag_align (int alignment, int fill_character, int max)
{
if (now_seg == absolute_section)
{
addressT new_off;
+ addressT mask;
- new_off = ((abs_section_offset + alignment - 1)
- &~ ((1 << alignment) - 1));
+ mask = (~(addressT) 0) << alignment;
+ new_off = (abs_section_offset + ~mask) & mask;
if (max == 0 || new_off - abs_section_offset <= (addressT) max)
abs_section_offset = new_off;
}
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;
+void
+frag_align_pattern (int alignment, const char *fill_pattern,
+ int n_fill, int max)
{
char *p;
memcpy (p, fill_pattern, n_fill);
}
+/* The NOP_OPCODE is for the alignment fill value. Fill it with a nop
+ instruction so that the disassembler does not choke on it. */
+#ifndef NOP_OPCODE
+#define NOP_OPCODE 0x00
+#endif
+
+/* Use this to restrict the amount of memory allocated for representing
+ the alignment code. Needs to be large enough to hold any fixed sized
+ prologue plus the replicating portion. */
+#ifndef MAX_MEM_FOR_RS_ALIGN_CODE
+ /* Assume that if HANDLE_ALIGN is not defined then no special action
+ is required to code fill, which means that we get just repeat the
+ one NOP_OPCODE byte. */
+# ifndef HANDLE_ALIGN
+# define MAX_MEM_FOR_RS_ALIGN_CODE 1
+# else
+# define MAX_MEM_FOR_RS_ALIGN_CODE ((1 << alignment) - 1)
+# endif
+#endif
+
+void
+frag_align_code (int alignment, int max)
+{
+ char *p;
+
+ p = frag_var (rs_align_code, MAX_MEM_FOR_RS_ALIGN_CODE, 1,
+ (relax_substateT) max, (symbolS *) 0,
+ (offsetT) alignment, (char *) 0);
+ *p = NOP_OPCODE;
+}
+
addressT
-frag_now_fix ()
+frag_now_fix_octets (void)
{
if (now_seg == absolute_section)
return abs_section_offset;
- return (addressT) ((char*) obstack_next_free (&frchain_now->frch_obstack)
- - frag_now->fr_literal);
+
+ return ((char *) obstack_next_free (&frchain_now->frch_obstack)
+ - frag_now->fr_literal);
+}
+
+addressT
+frag_now_fix (void)
+{
+ return frag_now_fix_octets () / OCTETS_PER_BYTE;
}
void
-frag_append_1_char (datum)
- int datum;
+frag_append_1_char (int datum)
{
+ frag_alloc_check (&frchain_now->frch_obstack);
if (obstack_room (&frchain_now->frch_obstack) <= 1)
{
frag_wane (frag_now);
obstack_1grow (&frchain_now->frch_obstack, datum);
}
-/* end of frags.c */
+/* Return TRUE if FRAG1 and FRAG2 have a fixed relationship between
+ their start addresses. Set OFFSET to the difference in address
+ not already accounted for in the frag FR_ADDRESS. */
+
+bfd_boolean
+frag_offset_fixed_p (const fragS *frag1, const fragS *frag2, bfd_vma *offset)
+{
+ const fragS *frag;
+ bfd_vma off;
+
+ /* Start with offset initialised to difference between the two frags.
+ Prior to assigning frag addresses this will be zero. */
+ off = frag1->fr_address - frag2->fr_address;
+ if (frag1 == frag2)
+ {
+ *offset = off;
+ return TRUE;
+ }
+
+ /* Maybe frag2 is after frag1. */
+ frag = frag1;
+ while (frag->fr_type == rs_fill)
+ {
+ off += frag->fr_fix + frag->fr_offset * frag->fr_var;
+ frag = frag->fr_next;
+ if (frag == NULL)
+ break;
+ if (frag == frag2)
+ {
+ *offset = off;
+ return TRUE;
+ }
+ }
+
+ /* Maybe frag1 is after frag2. */
+ off = frag1->fr_address - frag2->fr_address;
+ frag = frag2;
+ while (frag->fr_type == rs_fill)
+ {
+ off -= frag->fr_fix + frag->fr_offset * frag->fr_var;
+ frag = frag->fr_next;
+ if (frag == NULL)
+ break;
+ if (frag == frag1)
+ {
+ *offset = off;
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
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