From 058430b4a1ed7441dfc2e167bfdb9dc89ea9a209 Mon Sep 17 00:00:00 2001
From: Alan Modra <amodra@gmail.com>
Date: Tue, 17 Nov 2020 12:41:36 +1030
Subject: Re: Stop Gas from generating line info or address ranges

	* doc/as.texi (.nop): Document optional size arg.
	* dwarf2dbg.c (dwarf2_gen_line_info_1): Only check SEC_ALLOC
	when ELF.  Warn whenever dwarf line number information is ignored.
	* frags.c (frag_offset_ignore_align_p): New function.
	* frags.h (frag_offset_ignore_align_p): Declare.
	* read.c (s_nop): Extend to support optional size arg.
	* testsuite/gas/elf/dwarf2-20.d: Expect warnings, and exact range.
	* testsuite/gas/elf/dwarf2-20.s: Emit 16 bytes worth of nops.
	* testsuite/gas/m68hc11/indexed12.d: Expect warnings.
---
 gas/frags.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

(limited to 'gas/frags.c')

diff --git a/gas/frags.c b/gas/frags.c
index c926ec3..9ed4d7b 100644
--- a/gas/frags.c
+++ b/gas/frags.c
@@ -468,6 +468,48 @@ frag_offset_fixed_p (const fragS *frag1, const fragS *frag2, offsetT *offset)
   return FALSE;
 }
 
+/* Return TRUE if FRAG2 follows FRAG1 with a fixed relationship
+   between the two assuming alignment frags do nothing.  Set OFFSET to
+   the difference in address not already accounted for in the frag
+   FR_ADDRESS.  */
+
+bfd_boolean
+frag_offset_ignore_align_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;
+    }
+
+  frag = frag1;
+  while (frag->fr_type == rs_fill
+	 || frag->fr_type == rs_align
+	 || frag->fr_type == rs_align_code
+	 || frag->fr_type == rs_align_test)
+    {
+      if (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;
+	}
+    }
+
+  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
-- 
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