Imported binutils-2.20

[msp430-binutils.git] / gold / compressed_output.cc

diff --git a/gold/compressed_output.cc b/gold/compressed_output.cc
new file mode 100644 (file)
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+++ b/gold/compressed_output.cc
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+// compressed_output.cc -- manage compressed output sections for gold
+
+// Copyright 2007, 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@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"
+
+#ifdef HAVE_ZLIB_H
+#include <zlib.h>
+#endif
+
+#include "parameters.h"
+#include "options.h"
+#include "compressed_output.h"
+
+namespace gold
+{
+
+// Compress UNCOMPRESSED_DATA of size UNCOMPRESSED_SIZE.  Returns true
+// if it successfully compressed, false if it failed for any reason
+// (including not having zlib support in the library).  If it returns
+// true, it allocates memory for the compressed data using new, and
+// sets *COMPRESSED_DATA and *COMPRESSED_SIZE to appropriate values.
+// It also writes a header before COMPRESSED_DATA: 4 bytes saying
+// "ZLIB", and 8 bytes indicating the uncompressed size, in big-endian
+// order.
+
+#ifdef HAVE_ZLIB_H
+
+static bool
+zlib_compress(const unsigned char* uncompressed_data,
+              unsigned long uncompressed_size,
+              unsigned char** compressed_data,
+              unsigned long* compressed_size)
+{
+  const int header_size = 12;
+  *compressed_size = uncompressed_size + uncompressed_size / 1000 + 128;
+  *compressed_data = new unsigned char[*compressed_size + header_size];
+
+  int compress_level;
+  if (parameters->options().optimize() >= 1)
+    compress_level = 9;
+  else
+    compress_level = 1;
+
+  int rc = compress2(reinterpret_cast<Bytef*>(*compressed_data) + header_size,
+                     compressed_size,
+                     reinterpret_cast<const Bytef*>(uncompressed_data),
+                     uncompressed_size,
+                     compress_level);
+  if (rc == Z_OK)
+    {
+      memcpy(*compressed_data, "ZLIB", 4);
+      elfcpp::Swap_unaligned<64, true>::writeval(*compressed_data + 4,
+                                                uncompressed_size);
+      *compressed_size += header_size;
+      return true;
+    }
+  else
+    {
+      delete[] *compressed_data;
+      *compressed_data = NULL;
+      return false;
+    }
+}
+
+#else // !defined(HAVE_ZLIB_H)
+
+static bool
+zlib_compress(const unsigned char*, unsigned long,
+              unsigned char**, unsigned long*)
+{
+  return false;
+}
+
+#endif // !defined(HAVE_ZLIB_H)
+
+// Class Output_compressed_section.
+
+// Set the final data size of a compressed section.  This is where
+// we actually compress the section data.
+
+void
+Output_compressed_section::set_final_data_size()
+{
+  off_t uncompressed_size = this->postprocessing_buffer_size();
+
+  // (Try to) compress the data.
+  unsigned long compressed_size;
+  unsigned char* uncompressed_data = this->postprocessing_buffer();
+
+  // At this point the contents of all regular input sections will
+  // have been copied into the postprocessing buffer, and relocations
+  // will have been applied.  Now we need to copy in the contents of
+  // anything other than a regular input section.
+  this->write_to_postprocessing_buffer();
+
+  bool success = false;
+  if (strcmp(this->options_->compress_debug_sections(), "zlib") == 0)
+    success = zlib_compress(uncompressed_data, uncompressed_size,
+                            &this->data_, &compressed_size);
+  if (success)
+    {
+      // This converts .debug_foo to .zdebug_foo
+      this->new_section_name_ = std::string(".z") + (this->name() + 1);
+      this->set_name(this->new_section_name_.c_str());
+      this->set_data_size(compressed_size);
+    }
+  else
+    {
+      gold_warning(_("not compressing section data: zlib error"));
+      gold_assert(this->data_ == NULL);
+      this->set_data_size(uncompressed_size);
+    }
+}
+
+// Write out a compressed section.  If we couldn't compress, we just
+// write it out as normal, uncompressed data.
+
+void
+Output_compressed_section::do_write(Output_file* of)
+{
+  off_t offset = this->offset();
+  off_t data_size = this->data_size();
+  unsigned char* view = of->get_output_view(offset, data_size);
+  if (this->data_ == NULL)
+    memcpy(view, this->postprocessing_buffer(), data_size);
+  else
+    memcpy(view, this->data_, data_size);
+  of->write_output_view(offset, data_size, view);
+}
+
+} // End namespace gold.