Create dwarf2/leb.[ch]

This moves some scalar-unpacking code into a couple of new files,
dwarf2/leb.h and dwarf2/leb.c.

gdb/ChangeLog
2020-02-08  Tom Tromey  <tom@tromey.com>

	* dwarf2read.h (read_unsigned_leb128): Don't declare.
	* dwarf2read.c (read_1_byte, read_1_signed_byte, read_2_bytes)
	(read_2_signed_bytes, read_3_bytes, read_4_bytes)
	(read_4_signed_bytes, read_8_bytes): Move to dwarf2/leb.h.
	(read_unsigned_leb128, read_signed_leb128): Move to dwarf2/leb.c.
	* dwarf2/leb.h: New file, from dwarf2read.c.
	* dwarf2/leb.c: New file, from dwarf2read.c.
	* dwarf2-frame.c (read_1_byte, read_4_bytes, read_8_bytes):
	Remove.
	* Makefile.in (CONFIG_SRC_SUBDIR): Add dwarf2.
	(COMMON_SFILES): Add dwarf2/leb.c.

Change-Id: Idd19647686c8f959d226a95fdfca4db47c6e96d0

1 files changed, 85 insertions, 0 deletions

diff --git a/gdb/dwarf2/leb.c b/gdb/dwarf2/leb.c
new file mode 100644
index 0000000..d26b48b
--- /dev/null
+++ b/gdb/dwarf2/leb.c
@@ -0,0 +1,85 @@
+/* Low-level DWARF 2 reading code
+
+   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+
+   Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
+   Inc.  with support from Florida State University (under contract
+   with the Ada Joint Program Office), and Silicon Graphics, Inc.
+   Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
+   based on Fred Fish's (Cygnus Support) implementation of DWARF 1
+   support.
+
+   This file is part of GDB.
+
+   This program 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 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "dwarf2/leb.h"
+
+ULONGEST
+read_unsigned_leb128 (bfd *abfd, const gdb_byte *buf,
+			  unsigned int *bytes_read_ptr)
+{
+  ULONGEST result;
+  unsigned int num_read;
+  int shift;
+  unsigned char byte;
+
+  result = 0;
+  shift = 0;
+  num_read = 0;
+  while (1)
+    {
+      byte = bfd_get_8 (abfd, buf);
+      buf++;
+      num_read++;
+      result |= ((ULONGEST) (byte & 127) << shift);
+      if ((byte & 128) == 0)
+	{
+	  break;
+	}
+      shift += 7;
+    }
+  *bytes_read_ptr = num_read;
+  return result;
+}
+
+LONGEST
+read_signed_leb128 (bfd *abfd, const gdb_byte *buf,
+		    unsigned int *bytes_read_ptr)
+{
+  ULONGEST result;
+  int shift, num_read;
+  unsigned char byte;
+
+  result = 0;
+  shift = 0;
+  num_read = 0;
+  while (1)
+    {
+      byte = bfd_get_8 (abfd, buf);
+      buf++;
+      num_read++;
+      result |= ((ULONGEST) (byte & 127) << shift);
+      shift += 7;
+      if ((byte & 128) == 0)
+	{
+	  break;
+	}
+    }
+  if ((shift < 8 * sizeof (result)) && (byte & 0x40))
+    result |= -(((ULONGEST) 1) << shift);
+  *bytes_read_ptr = num_read;
+  return result;
+}