Initial revision

1 files changed, 285 insertions, 0 deletions

diff --git a/gas/frags.c b/gas/frags.c
new file mode 100644
index 0000000..3526603
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+++ b/gas/frags.c
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+/* frags.c - manage frags -
+   Copyright (C) 1987, 1990, 1991 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* static const char rcsid[] = "$Id$"; */
+
+#include "as.h"
+#include "subsegs.h"
+#include "obstack.h"
+
+struct obstack  frags;	/* All, and only, frags live here. */
+
+fragS zero_address_frag = {
+	0,			/* fr_address */
+	NULL,			/* fr_next */
+	0,			/* fr_fix */
+	0,			/* fr_var */
+	0,			/* fr_symbol */
+	0,			/* fr_offset */
+	NULL,			/* fr_opcode */
+	rs_fill,		/* fr_type */
+	0,			/* fr_subtype */
+	0,			/* fr_pcrel_adjust */
+	0,			/* fr_bsr */
+	0			/* fr_literal [0] */
+};
+
+fragS bss_address_frag = {
+	0,			/* fr_address. Gets filled in to make up
+				   sy_value-s. */
+	NULL,			/* fr_next */
+	0,			/* fr_fix */
+	0,			/* fr_var */
+	0,			/* fr_symbol */
+	0,			/* fr_offset */
+	NULL,			/* fr_opcode */
+	rs_fill,		/* fr_type */
+	0,			/* fr_subtype */
+	0,			/* fr_pcrel_adjust */
+	0,			/* fr_bsr */
+	0			/* fr_literal [0] */
+};
+
+/*
+ *			frag_grow()
+ *
+ * Internal.
+ * 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.
+ */
+static void frag_grow(nchars)
+unsigned int nchars;
+{
+    if (obstack_room (&frags) < nchars) {
+	unsigned int n,oldn;
+	long oldc;
+
+	frag_wane(frag_now);
+	frag_new(0);
+	oldn=(unsigned)-1;
+	oldc=frags.chunk_size;
+	frags.chunk_size=2*nchars;
+	while((n=obstack_room(&frags))<nchars && n<oldn) {
+		frag_wane(frag_now);
+		frag_new(0);
+		oldn=n;
+	}
+	frags.chunk_size=oldc;
+    }
+    if (obstack_room (&frags) < nchars)
+	as_fatal("Can't extend frag %d. chars", nchars);
+} /* frag_grow() */
+
+/*
+ *			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)
+int old_frags_var_max_size;	/* Number of chars (already allocated on
+				   obstack frags) */
+ /* in variable_length part of frag. */
+{
+    register    fragS * former_last_fragP;
+/*    char   *throw_away_pointer; JF unused */
+    register    frchainS * frchP;
+    long	tmp;		/* JF */
+
+    frag_now->fr_fix = (char *) (obstack_next_free (&frags)) -
+    (frag_now->fr_literal) - old_frags_var_max_size;
+ /* Fix up old frag's fr_fix. */
+
+    obstack_finish (&frags);
+ /* This will align the obstack so the */
+ /* next struct we allocate on it will */
+ /* begin at a correct boundary. */
+    frchP = frchain_now;
+    know (frchP);
+    former_last_fragP = frchP->frch_last;
+    know (former_last_fragP);
+    know (former_last_fragP == frag_now);
+    obstack_blank (&frags, SIZEOF_STRUCT_FRAG);
+ /* We expect this will begin at a correct */
+ /* boundary for a struct. */
+    tmp=obstack_alignment_mask(&frags);
+    obstack_alignment_mask(&frags)=0;		/* Turn off alignment */
+    						/* If we ever hit a machine
+						   where strings must be
+						   aligned, we Lose Big */
+ frag_now=(fragS *)obstack_finish(&frags);
+    obstack_alignment_mask(&frags)=tmp;		/* Restore alignment */
+
+ /* Just in case we don't get zero'd bytes */
+ bzero(frag_now, SIZEOF_STRUCT_FRAG);
+
+/*    obstack_unaligned_done (&frags, &frag_now); */
+/*    know (frags.obstack_c_next_free == frag_now->fr_literal); */
+ /* 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;
+    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;
+
+    frag_grow (nchars);
+    retval = obstack_next_free (&frags);
+    obstack_blank_fast (&frags, 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;
+long offset;
+char *opcode;
+{
+    register char  *retval;
+
+    frag_grow (max_chars);
+    retval = obstack_next_free (&frags);
+    obstack_blank_fast (&frags, 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;
+    /* default these to zero. */
+    frag_now->fr_pcrel_adjust = 0;
+    frag_now->fr_bsr = 0;
+    frag_new (max_chars);
+    return (retval);
+}				/* frag_var() */
+
+/*
+ *			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.
+ *      Two new arguments have been added.
+ */
+
+char *frag_variant(type, max_chars, var, subtype, symbol, offset, opcode, pcrel_adjust,bsr)
+     relax_stateT	 type;
+     int		 max_chars;
+     int		 var;
+     relax_substateT	 subtype;
+     symbolS		*symbol;
+     long		 offset;
+     char		*opcode;
+     int		 pcrel_adjust;
+     char		 bsr;
+{
+    register char  *retval;
+
+/*    frag_grow (max_chars); */
+    retval = obstack_next_free (&frags);
+/*  obstack_blank_fast (&frags, max_chars); */ /* OVE: so far the only diff */
+    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;
+    frag_now->fr_pcrel_adjust = pcrel_adjust;
+    frag_now->fr_bsr = bsr;
+    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;
+}
+
+/*
+ *			frag_align()
+ *
+ * Make a frag for ".align foo,bar". Call is "frag_align (foo,bar);".
+ * Foo & bar are absolute integers.
+ *
+ * Call to close off the current frag with a ".align", then start a new
+ * (so far empty) frag, in the same subsegment as the last frag.
+ */
+
+void frag_align(alignment, fill_character)
+int alignment;
+int fill_character;
+{
+    *(frag_var (rs_align, 1, 1, (relax_substateT)0, (symbolS *)0,
+ (long)alignment, (char *)0)) = fill_character;
+} /* frag_align() */
+
+/* end: frags.c */