/* frags.c - manage frags -
- Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 97, 1998
- Free Software Foundation, Inc.
+ Copyright (C) 1987-2020 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"
#include "obstack.h"
extern fragS zero_address_frag;
-extern fragS bss_address_frag;
+extern fragS predefined_address_frag;
+
+static int totalfrags;
+
+int
+get_frag_count (void)
+{
+ return totalfrags;
+}
+
+void
+clear_frag_count (void)
+{
+ totalfrags = 0;
+}
\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;
+ predefined_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;
ptr = (fragS *) obstack_alloc (ob, SIZEOF_STRUCT_FRAG);
obstack_alignment_mask (ob) = oalign;
memset (ptr, 0, SIZEOF_STRUCT_FRAG);
+ totalfrags++;
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 off the current frag with a ".fill 0"
+ and begin a new frag. Then loop until the new frag has at least
+ nchars chars available. Does not set up any fields in frag_now. */
+
+void
+frag_grow (size_t 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;
- 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;
+ size_t oldc;
+ size_t newc;
+
+ /* 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)
+ newc = 2 * nchars;
+ else
+ newc = nchars + 0x10000;
+ newc += SIZEOF_STRUCT_FRAG;
+
+ /* Check for possible overflow. */
+ if (newc < nchars)
+ as_fatal (ngettext ("can't extend frag %lu char",
+ "can't extend frag %lu chars",
+ (unsigned long) nchars),
+ (unsigned long) nchars);
+
+ /* Force to allocate at least NEWC bytes, but not less than the
+ default. */
+ oldc = obstack_chunk_size (&frchain_now->frch_obstack);
+ if (newc > oldc)
+ obstack_chunk_size (&frchain_now->frch_obstack) = newc;
+
+ while (obstack_room (&frchain_now->frch_obstack) < nchars)
+ {
+ /* Not enough room in this frag. Close it and start a new one.
+ This must be done in a loop because the created frag may not
+ be big enough if the current obstack chunk is used. */
+ frag_wane (frag_now);
+ frag_new (0);
+ }
+
+ /* Restore the old chunk size. */
+ obstack_chunk_size (&frchain_now->frch_obstack) = oldc;
}
- if (obstack_room (&frchain_now->frch_obstack) < nchars)
- as_fatal (_("Can't extend frag %d. 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 (size_t 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_octets () - old_frags_var_max_size;
+ frag_now->fr_fix = frag_now_fix_octets ();
+ gas_assert (frag_now->fr_fix >= old_frags_var_max_size);
+ frag_now->fr_fix -= 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);
+ frag_now->fr_file = as_where (&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 (size_t 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;
- }
+ char *retval;
+ 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() */
+ return retval;
+}
\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.
- */
+/* Close the current frag, setting its fields for a relaxable frag. Start a
+ new frag. */
-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;
+static void
+frag_var_init (relax_stateT type, size_t max_chars, size_t 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_cgen.opinfo = 0;
#endif
#ifdef TC_FRAG_INIT
- TC_FRAG_INIT (frag_now);
+ TC_FRAG_INIT (frag_now, max_chars);
#endif
- as_where (&frag_now->fr_file, &frag_now->fr_line);
+ frag_now->fr_file = as_where (&frag_now->fr_line);
+
frag_new (max_chars);
- return (retval);
+}
+
+/* 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 (relax_stateT type, size_t max_chars, size_t var,
+ relax_substateT subtype, symbolS *symbol, offsetT offset,
+ char *opcode)
+{
+ char *retval;
+
+ frag_grow (max_chars);
+ retval = obstack_next_free (&frchain_now->frch_obstack);
+ obstack_blank_fast (&frchain_now->frch_obstack, max_chars);
+ frag_var_init (type, max_chars, var, subtype, symbol, offset, opcode);
+ 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, size_t max_chars, size_t var,
+ relax_substateT subtype, symbolS *symbol, offsetT offset,
+ char *opcode)
{
- register char *retval;
+ 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_var_init (type, max_chars, var, subtype, symbol, offset, opcode);
+
+ return retval;
+}
\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 (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. */
+
+size_t
+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,
+ size_t 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_octets ()
+frag_now_fix_octets (void)
{
if (now_seg == absolute_section)
return abs_section_offset;
- return ((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 ()
+frag_now_fix (void)
{
- return frag_now_fix_octets() / OCTETS_PER_BYTE;
+ /* Symbols whose section has SEC_ELF_OCTETS set,
+ resolve to octets instead of target bytes. */
+ if (now_seg->flags & SEC_OCTETS)
+ return frag_now_fix_octets ();
+ else
+ 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, offsetT *offset)
+{
+ const fragS *frag;
+ offsetT 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;
+}
+
+/* Return TRUE if we can determine whether FRAG2 OFF2 appears after
+ (strict >, not >=) FRAG1 OFF1, assuming it is not before. Set
+ *OFFSET so that resolve_expression will resolve an O_gt operation
+ between them to false (0) if they are guaranteed to be at the same
+ location, or to true (-1) if they are guaranteed to be at different
+ locations. Return FALSE conservatively, e.g. if neither result can
+ be guaranteed (yet).
+
+ They are known to be in the same segment, and not the same frag
+ (this is a fallback for frag_offset_fixed_p, that always takes care
+ of this case), and it is expected (from the uses this is designed
+ to simplify, namely location view increments) that frag2 is
+ reachable from frag1 following the fr_next links, rather than the
+ other way round. */
+
+bfd_boolean
+frag_gtoffset_p (valueT off2, const fragS *frag2,
+ valueT off1, const fragS *frag1, offsetT *offset)
+{
+ /* Insanity check. */
+ if (frag2 == frag1 || off1 > frag1->fr_fix)
+ return FALSE;
+
+ /* If the first symbol offset is at the end of the first frag and
+ the second symbol offset at the beginning of the second frag then
+ it is possible they are at the same address. Go looking for a
+ non-zero fr_fix in any frag between these frags. If found then
+ we can say the O_gt result will be true. If no such frag is
+ found we assume that frag1 or any of the following frags might
+ have a variable tail and thus the answer is unknown. This isn't
+ strictly true; some frags don't have a variable tail, but it
+ doesn't seem worth optimizing for those cases. */
+ const fragS *frag = frag1;
+ offsetT delta = off2 - off1;
+ for (;;)
+ {
+ delta += frag->fr_fix;
+ frag = frag->fr_next;
+ if (frag == frag2)
+ {
+ if (delta == 0)
+ return FALSE;
+ break;
+ }
+ /* If we run off the end of the frag chain then we have a case
+ where frag2 is not after frag1, ie. an O_gt expression not
+ created for .loc view. */
+ if (frag == NULL)
+ return FALSE;
+ }
+
+ *offset = (off2 - off1 - delta) * OCTETS_PER_BYTE;
+ return TRUE;
+}