ccache/NEWS
Joel Rosdahl 5ea294ef76 Force new hash sums
All hash sums will from now on be different from those calculated by ccache
2.4, instead of only hash sums for compressed files. This makes hash sums for
compressed and uncompressed files equal again, which reopens for conversion
between compressed and uncompressed files, should the need arise.
2010-02-21 18:18:03 +01:00

111 lines
4.3 KiB
Plaintext

Changes since ccache 2.4
------------------------
New features and improvements:
- ccache now has a "direct mode" where it computes a hash of the source code
and compiler arguments without running the preprocessor. By not running the
preprocessor, CPU usage is reduced; the runtime is about 0.2-1.0 times that
of ccache running in traditional mode. The relative speedup will be higher
when I/O is fast (e.g., when files are in the disk cache). The direct mode
can be disabled by setting CCACHE_NODIRECT.
- When hashing the output from the preprocessor, absolute paths are rewritten
to relative paths, but only for paths under the directory specified by
CCACHE_BASEDIR. Paths specified by -I and similar options get the same
treatment. This is done to get cache hits even when compiling with -g and
when using absolute include directory paths. Absolute paths in the standard
error text will also be more accurate. The default value of CCACHE_BASEDIR
is the current working directory. To disable the rewriting, set
CCACHE_BASEDIR to the empty string.
- Object files are now by default stored compressed in the cache. The runtime
cost is negligible, and more files will fit in the ccache directory and in
the disk cache. CCACHE_NOCOMPRESS can be set to disable object file
compression.
- Added CCACHE_NOHASH_SIZE_MTIME option that tells ccache not to hash the
real compiler's size and modification time.
- Added CCACHE_HASH_COMPILER option that tells ccache to hash binary of the
compiler instead of hashing just its size and modification time.
- Temporary files are now created in the directory they will end up in. This
makes ccache more friendly to Linux's directory layout.
- Added support for long command-line options.
- A CACHEDIR.TAG file is now created in the cache directory. See
<http://www.brynosaurus.com/cachedir/>.
- Improved logging.
- By default, ccache now puts temporary files in CCACHE_DIR/tmp to avoid
cluttering the top directory.
- Improved the test suite and added tests for most of the new functionality.
It's now also possible to specify a subset of tests to run.
- Standard error output from the compiler is now only stored in the cache if
it's non-empty.
- Added installcheck and distcheck make targets.
- Clarified cache size limit options' semantics
Bug fixes:
- Fixed build on FreeBSD.
- Improved detection of home directory.
- User-defined CPPFLAGS and LDFLAGS are now respected in the Makefile.
- Fixed NFS issues.
- Bail out on profiling options --coverage, -fprofile-arcs,
-fprofile-generate, -fprofile-use and -ftest-coverage. [Bug #7091]
- -MD/-MMD options without -MT/-MF are now handled correctly. [Bug #7093]
- Added support for -Wp,-MD and -Wp,-MMD options.
- Corrected LRU cleanup handling of object files.
- utimes() is now used instead of utime() when available. [Bug #7089]
- Non-writable cache directories are now handled gracefully.
- Corrected documentation about sharing the cache directory.
- Fixed compilation warnings from GCC 4.3.
- The command specified by CCACHE_PREFIX is no longer part of the hash.
- Fixed bad memory access spotted by Valgrind.
- Fixed a bug in x_realloc. [Bug #7090]
- Removed deprecated constructions from ccache.yo.
- Freed memory is no longer referenced when compiling a .i/.ii file and
falling back to running the real compiler. [Bug #7092]
- The test suite is now immune to external values of the CCACHE_* environment
variables. [Bug #7161]
Compatibility notes:
- The way the hashes are calculated has changed, so you won't get cache hits
for compilation results stored by older ccache versions. In fact, you might
as well clear the old cache directory if you want, unless if you plan to
keep using an older ccache version.
- The statistics counters "files in cache" and "cache size" now only include
object files (previously, files containing cached standard error output
were counted as well). Consequently, the "max file" and "max cache size"
settings now specify thresholds for object files count and size.
- Using ccache 3.0 and older ccache versions with the same cache directory
works OK, except that the statistics counters will be a bit messed up.