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authorDoug Kwan <dougkwan@google.com>2009-12-09 03:02:28 +0000
committerDoug Kwan <dougkwan@google.com>2009-12-09 03:02:28 +0000
commit4f7872716e8b73149e9024e1b95db6c3cfa66bd1 (patch)
treec33f338158eadac574de9434ef24c217bfb2cb08 /gold/int_encoding.cc
parent829da89821d7f0b7663b8314128fa06878d228e0 (diff)
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2009-12-08 Doug Kwan <dougkwan@google.com>
* Makefile.am (CCFILES): Add attributes.cc and int_encoding.cc. (HFILES): Add attributes.h and int_encoding.h. * Makefile.in: Regenerate. * dwarf_reader.cc (read_unsigned_LEB_128, read_signed_LEB_128): Move function definitions to int_encoding.cc * dwarf_reader.h (read_unsigned_LEB_128, read_signed_LEB_128): Move prototypes to int_encoding.h * reduced_debug_output.cc (int_encoding.h): New include. (write_unsigned_LEB_128, get_length_as_unsigned_LEB_128): Move function definitions to int_encoding.cc (insert_into_vector, read_from_pointer): Move template definitions to int_encoding.h * attributes.cc: New file. * attributes.h: New file. * int_encoding.cc: New file. * int_encoding.h: New file.
Diffstat (limited to 'gold/int_encoding.cc')
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diff --git a/gold/int_encoding.cc b/gold/int_encoding.cc
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+// varint.cc -- variable length and unaligned integer encoding support.
+
+// Copyright 2009 Free Software Foundation, Inc.
+// Written by Doug Kwan <dougkwan@google.com> by refactoring scattered
+// contents from other files in gold. Original code written by Ian
+// Lance Taylor <iant@google.com> and Caleb Howe <cshowe@google.com>.
+
+// This file is part of gold.
+
+// 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, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include "gold.h"
+
+#include <vector>
+
+#include "int_encoding.h"
+
+namespace gold {
+
+// Read an unsigned LEB128 number. Each byte contains 7 bits of
+// information, plus one bit saying whether the number continues or
+// not.
+
+uint64_t
+read_unsigned_LEB_128(const unsigned char* buffer, size_t* len)
+{
+ uint64_t result = 0;
+ size_t num_read = 0;
+ unsigned int shift = 0;
+ unsigned char byte;
+
+ do
+ {
+ if (num_read >= 64 / 7)
+ {
+ gold_warning(_("Unusually large LEB128 decoded, "
+ "debug information may be corrupted"));
+ break;
+ }
+ byte = *buffer++;
+ num_read++;
+ result |= (static_cast<uint64_t>(byte & 0x7f)) << shift;
+ shift += 7;
+ }
+ while (byte & 0x80);
+
+ *len = num_read;
+
+ return result;
+}
+
+// Read a signed LEB128 number. These are like regular LEB128
+// numbers, except the last byte may have a sign bit set.
+
+int64_t
+read_signed_LEB_128(const unsigned char* buffer, size_t* len)
+{
+ int64_t result = 0;
+ int shift = 0;
+ size_t num_read = 0;
+ unsigned char byte;
+
+ do
+ {
+ if (num_read >= 64 / 7)
+ {
+ gold_warning(_("Unusually large LEB128 decoded, "
+ "debug information may be corrupted"));
+ break;
+ }
+ byte = *buffer++;
+ num_read++;
+ result |= (static_cast<uint64_t>(byte & 0x7f) << shift);
+ shift += 7;
+ }
+ while (byte & 0x80);
+
+ if ((shift < 8 * static_cast<int>(sizeof(result))) && (byte & 0x40))
+ result |= -((static_cast<int64_t>(1)) << shift);
+ *len = num_read;
+ return result;
+}
+
+void
+write_unsigned_LEB_128(std::vector<unsigned char>* buffer, uint64_t value)
+{
+ do
+ {
+ unsigned char current_byte = value & 0x7f;
+ value >>= 7;
+ if (value != 0)
+ {
+ current_byte |= 0x80;
+ }
+ buffer->push_back(current_byte);
+ }
+ while (value != 0);
+}
+
+size_t
+get_length_as_unsigned_LEB_128(uint64_t value)
+{
+ size_t length = 0;
+ do
+ {
+ unsigned char current_byte = value & 0x7f;
+ value >>= 7;
+ if (value != 0)
+ {
+ current_byte |= 0x80;
+ }
+ length++;
+ }
+ while (value != 0);
+ return length;
+}
+
+} // End namespace gold.