-// compressed_output.cc -- manage compressed output sections for gold
+// compressed_output.cc -- manage compressed debug sections for gold
-// Copyright 2007 Free Software Foundation, Inc.
+// Copyright (C) 2007-2014 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
namespace gold
{
+#ifdef HAVE_ZLIB_H
+
// 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.
-
-#ifdef HAVE_ZLIB_H
+// It also writes a header before COMPRESSED_DATA: 4 bytes saying
+// "ZLIB", and 8 bytes indicating the uncompressed size, in big-endian
+// order.
static bool
-zlib_compress(const char* uncompressed_data, unsigned long uncompressed_size,
- char** compressed_data, unsigned long* compressed_size)
+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 char[*compressed_size];
+ *compressed_data = new unsigned char[*compressed_size + header_size];
int compress_level;
- if (parameters->optimization_level() >= 1)
+ if (parameters->options().optimize() >= 1)
compress_level = 9;
else
compress_level = 1;
- int rc = compress2(reinterpret_cast<Bytef*>(*compressed_data),
+ 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)
- return true;
+ {
+ 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;
}
}
+// Decompress COMPRESSED_DATA of size COMPRESSED_SIZE, into a buffer
+// UNCOMPRESSED_DATA of size UNCOMPRESSED_SIZE. Returns TRUE if it
+// decompressed successfully, false if it failed. The buffer, of
+// appropriate size, is provided by the caller, and is typically part
+// of the memory-mapped output file.
+
+static bool
+zlib_decompress(const unsigned char* compressed_data,
+ unsigned long compressed_size,
+ unsigned char* uncompressed_data,
+ unsigned long uncompressed_size)
+{
+ z_stream strm;
+ int rc;
+
+ /* It is possible the section consists of several compressed
+ buffers concatenated together, so we uncompress in a loop. */
+ strm.zalloc = NULL;
+ strm.zfree = NULL;
+ strm.opaque = NULL;
+ strm.avail_in = compressed_size;
+ strm.next_in = const_cast<Bytef*>(compressed_data);
+ strm.avail_out = uncompressed_size;
+
+ rc = inflateInit(&strm);
+ while (strm.avail_in > 0)
+ {
+ if (rc != Z_OK)
+ return false;
+ strm.next_out = ((Bytef*) uncompressed_data
+ + (uncompressed_size - strm.avail_out));
+ rc = inflate(&strm, Z_FINISH);
+ if (rc != Z_STREAM_END)
+ return false;
+ rc = inflateReset(&strm);
+ }
+ rc = inflateEnd(&strm);
+ if (rc != Z_OK || strm.avail_out != 0)
+ return false;
+
+ return true;
+}
+
#else // !defined(HAVE_ZLIB_H)
static bool
-zlib_compress(const char*, unsigned long, char**, unsigned long*)
+zlib_compress(const unsigned char*, unsigned long,
+ unsigned char**, unsigned long*)
+{
+ return false;
+}
+
+static bool
+zlib_decompress(const unsigned char*, unsigned long,
+ unsigned char*, unsigned long)
{
return false;
}
#endif // !defined(HAVE_ZLIB_H)
-// After compressing an output section, we rename it from foo to
-// foo.zlib.nnnn, where nnnn is the uncompressed size of the section.
+// Read the compression header of a compressed debug section and return
+// the uncompressed size.
-static std::string
-zlib_compressed_suffix(unsigned long uncompressed_size)
+uint64_t
+get_uncompressed_size(const unsigned char* compressed_data,
+ section_size_type compressed_size)
{
- char size_string[64];
- snprintf(size_string, sizeof(size_string), "%lu", uncompressed_size);
- return std::string(".zlib.") + size_string;
+ const unsigned int zlib_header_size = 12;
+
+ /* Verify the compression header. Currently, we support only zlib
+ compression, so it should be "ZLIB" followed by the uncompressed
+ section size, 8 bytes in big-endian order. */
+ if (compressed_size >= zlib_header_size
+ && strncmp(reinterpret_cast<const char*>(compressed_data),
+ "ZLIB", 4) == 0)
+ return elfcpp::Swap_unaligned<64, true>::readval(compressed_data + 4);
+ return -1ULL;
+}
+
+// Decompress a compressed debug section directly into the output file.
+
+bool
+decompress_input_section(const unsigned char* compressed_data,
+ unsigned long compressed_size,
+ unsigned char* uncompressed_data,
+ unsigned long uncompressed_size)
+{
+ const unsigned int zlib_header_size = 12;
+
+ /* Verify the compression header. Currently, we support only zlib
+ compression, so it should be "ZLIB" followed by the uncompressed
+ section size, 8 bytes in big-endian order. */
+ if (compressed_size >= zlib_header_size
+ && strncmp(reinterpret_cast<const char*>(compressed_data),
+ "ZLIB", 4) == 0)
+ {
+ unsigned long uncompressed_size_check =
+ elfcpp::Swap_unaligned<64, true>::readval(compressed_data + 4);
+ gold_assert(uncompressed_size_check == uncompressed_size);
+ return zlib_decompress(compressed_data + zlib_header_size,
+ compressed_size - zlib_header_size,
+ uncompressed_data,
+ uncompressed_size);
+ }
+ return false;
}
// Class Output_compressed_section.
// (Try to) compress the data.
unsigned long compressed_size;
- unsigned char* u_uncompressed_data = this->postprocessing_buffer();
- char* uncompressed_data = reinterpret_cast<char*>(u_uncompressed_data);
+ 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
this->write_to_postprocessing_buffer();
bool success = false;
- if (this->options_->zlib_compress_debug_sections())
+ if (strcmp(this->options_->compress_debug_sections(), "zlib") == 0)
success = zlib_compress(uncompressed_data, uncompressed_size,
&this->data_, &compressed_size);
if (success)
{
- std::string suffix(zlib_compressed_suffix(uncompressed_size));
- this->new_section_name_ = std::string(this->name()) + suffix;
+ // 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);
}
projects / platform / upstream / binutils.git / blobdiff