-Changes since ccache 2.4
-------------------------
+News for ccache 3.0 (UNRELEASED)
+Changes since ccache 2.4:
-New features and improvements:
+ UPGRADING NOTES:
- - 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.
+ - The way the hashes are calculated has changed, so you won't get cache
+ hits for compilation results stored by older ccache versions.
- - 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.
+ - The statistics counters "files in cache" and "cache size" now only count
+ object files. (Previously, files containing cached standard error output
+ were counted as well.) The existing values of the two counters will be
+ erroneous at first after the upgrade, but will correct themselves
+ eventually when enough cleanups have been made, or when you run "ccache
+ --cleanup".
- - 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.
+ - The "max file" and "max cache size" settings now specify thresholds for
+ object files count and size.
- - Added CCACHE_COMPILERCHECK option that tells ccache what
- compiler-identifying information to hash to ensure that results retrieved
- from the cache are accurate. Possible values are: none (don't hash
- anything), mtime (hash the compiler's mtime and size) and content (hash the
- content of the compiler binary). The default is mtime.
+ - Because of the changes mentioned above, you might as well clear the old
+ cache directory with "ccache -C" if you want, unless you plan to keep
+ using an older ccache version.
- - Temporary files are now created in the directory they will end up in. This
- makes ccache more friendly to Linux's directory layout.
+ NEW FEATURES AND IMPROVEMENTS:
- - Added support for long command-line options.
+ - 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.
- - A CACHEDIR.TAG file is now created in the cache directory. See
- <http://www.brynosaurus.com/cachedir/>.
+ - 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.
- - Improved logging.
+ - 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.
- - By default, ccache now puts temporary files in CCACHE_DIR/tmp to avoid
- cluttering the top directory.
+ - Added CCACHE_COMPILERCHECK option that tells ccache what
+ compiler-identifying information to hash to ensure that results retrieved
+ from the cache are accurate. Possible values are: none (don't hash
+ anything), mtime (hash the compiler's mtime and size) and content (hash
+ the content of the compiler binary). The default is mtime.
- - 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.
+ - Temporary files are now created in the directory they will end up in.
+ This makes ccache more friendly to Linux's directory layout.
- - Standard error output from the compiler is now only stored in the cache if
- it's non-empty.
+ - Added support for long command-line options.
- - If the compiler produces no object file or an empty object file, but gives
- a zero exit status (could be due to a file system problem, a buggy program
- specified by CCACHE_PREFIX, etc.), ccache copes with it properly.
+ - A CACHEDIR.TAG file is now created in the cache directory. See
+ <http://www.brynosaurus.com/cachedir/>.
- - Added installcheck and distcheck make targets.
+ - Improved logging.
- - Clarified cache size limit options' semantics
+ - By default, ccache now puts temporary files in CCACHE_DIR/tmp to avoid
+ cluttering the top directory.
- - Improved display of cache max size values.
+ - 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.
-Bug fixes:
+ - Standard error output from the compiler is now only stored in the cache
+ if it's non-empty.
- - Fixed build on FreeBSD.
+ - If the compiler produces no object file or an empty object file, but
+ gives a zero exit status (could be due to a file system problem, a buggy
+ program specified by CCACHE_PREFIX, etc.), ccache copes with it properly.
- - Improved detection of home directory.
+ - Added installcheck and distcheck make targets.
- - User-defined CPPFLAGS and LDFLAGS are now respected in the Makefile.
+ - Clarified cache size limit options' semantics
- - Fixed NFS issues.
+ - Improved display of cache max size values.
- - Bail out on too hard compiler options --coverage, -fprofile-arcs,
- -fprofile-generate, -fprofile-use, -ftest-coverage and -save-temps. Also
- bail out on "@file" style options.
+ BUG FIXES:
- - -MD/-MMD options without -MT/-MF are now handled correctly.
+ - Fixed build on FreeBSD.
- - Added support for -Wp,-MD and -Wp,-MMD options.
+ - Improved detection of home directory.
- - Corrected LRU cleanup handling of object files.
+ - User-defined CPPFLAGS and LDFLAGS are now respected in the Makefile.
- - utimes() is now used instead of utime() when available.
+ - Fixed NFS issues.
- - Non-writable cache directories are now handled gracefully.
+ - Bail out on too hard compiler options --coverage, -fprofile-arcs,
+ -fprofile-generate, -fprofile-use, -ftest-coverage and -save-temps. Also
+ bail out on "@file" style options.
- - Corrected documentation about sharing the cache directory.
+ - -MD/-MMD options without -MT/-MF are now handled correctly.
- - Fixed compilation warnings from GCC 4.3.
+ - Added support for -Wp,-MD and -Wp,-MMD options.
- - The command specified by CCACHE_PREFIX is no longer part of the hash.
+ - Corrected LRU cleanup handling of object files.
- - Fixed bad memory access spotted by Valgrind.
+ - utimes() is now used instead of utime() when available.
- - Fixed a bug in x_realloc.
+ - Non-writable cache directories are now handled gracefully.
- - Removed deprecated constructions from ccache.yo.
+ - Corrected documentation about sharing the cache directory.
- - Freed memory is no longer referenced when compiling a .i/.ii file and
- falling back to running the real compiler.
+ - Fixed compilation warnings from GCC 4.3.
- - The test suite is now immune to external values of the CCACHE_* environment
- variables.
+ - The command specified by CCACHE_PREFIX is no longer part of the hash.
-Upgrading notes:
+ - Fixed bad memory access spotted by Valgrind.
- - The way the hashes are calculated has changed, so you won't get cache hits
- for compilation results stored by older ccache versions.
+ - Fixed a bug in x_realloc.
- - The statistics counters "files in cache" and "cache size" now only count
- object files. (Previously, files containing cached standard error output
- were counted as well.) The existing values of the two counters will be
- erroneous at first after the upgrade, but will correct themselves
- eventually when enough cleanups have been made, or when you run "ccache
- --cleanup".
+ - Removed deprecated constructions from ccache.yo.
- - The "max file" and "max cache size" settings now specify thresholds for
- object files count and size.
+ - Freed memory is no longer referenced when compiling a .i/.ii file and
+ falling back to running the real compiler.
- - Because of the changes mentioned above, you might as well clear the old
- cache directory with "ccache -C" if you want, unless you plan to keep using
- an older ccache version.
+ - The test suite is now immune to external values of the CCACHE_*
+ environment variables.
projects / thirdparty / ccache.git / commitdiff
