ccache 3.0.1

Release date: 2010-07-15

Bug fixes

  • The statistics counter “called for link” is now correctly updated when linking with a single object file.

  • Fixed a problem with out-of-source builds.

ccache 3.0

Release date: 2010-06-20

General

  • ccache is now licensed under the GNU General Public License (GPL) version 3 or later.

Upgrade notes

  • The way the hashes are calculated has changed, so you won’t get cache hits for compilation results stored by older ccache versions. Because of this, you might as well clear the old cache directory with ccache --clear if you want, unless you plan to keep using an older ccache version.

New features and improvements

  • ccache now has a “direct mode” where it computes a hash of the source code (including all included files) and compiler options without running the preprocessor. By not running the preprocessor, CPU usage is reduced; the speed is somewhere between 1 and 5 times that of ccache running in traditional mode, depending on the circumstances. The 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.

  • Support has been added for rewriting absolute paths to relative paths when hashing, in order to increase cache hit rate when building the same source code in different directories even when compiling with -g and when using absolute include directory paths. This is done by setting the CCACHE_BASEDIR environment variable to an absolute path that specifies which paths to rewrite.

  • Object files are now optionally stored compressed in the cache. The runtime cost is negligible, and more files will fit in the ccache directory and in the disk cache. Set CCACHE_COMPRESS to enable object file compression. Note that you can’t use compression in combination with the hard link feature.

  • A CCACHE_COMPILERCHECK option has been added. This option 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.

  • It is now possible to specify extra files whose contents should be included in the hash sum by setting the CCACHE_EXTRAFILES option.

  • Added support for Objective-C and Objective-C++. The statistics counter “not a C/C++ file” has been renamed to “unsupported source language”.

  • Added support for the -x compiler option.

  • Added support for long command-line options.

  • A CACHEDIR.TAG file is now created in the cache directory. See http://www.brynosaurus.com/cachedir/.

  • Messages printed to the debug log (specified by CCACHE_LOGFILE) have been improved.

  • You can relax some checks that ccache does in direct mode by setting CCACHE_SLOPPINESS. See the manual for more information.

  • CCACHE_TEMPDIR no longer needs to be on the same filesystem as CCACHE_DIR.

  • The default value of CCACHE_TEMPDIR has been changed to $CCACHE_DIR/tmp to avoid cluttering the top directory.

  • Temporary files that later will be moved into the cache are now created in the cache directory they will end up in. This makes ccache more friendly to Linux’s directory layout.

  • 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.

  • 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.

  • Added installcheck and distcheck make targets.

  • Clarified cache size limit options' and cleanup semantics.

  • Improved display of cache max size values.

  • The following options are no longer hashed in the preprocessor mode: -imacros, -imultilib, -iprefix, -iquote, -isysroot, -iwithprefix, -iwithprefixbefore, -nostdinc, -nostdinc++ and -U.

Bug fixes

  • Various portability improvements.

  • Improved detection of home directory.

  • User-defined CPPFLAGS and LDFLAGS are now respected in the Makefile.

  • Fixed NFS issues.

  • Computation of the hash sum has been improved to decrease the risk of hash collisions. For instance, the compiler options -X -Y and -X-Y previously contributed equally to the hash sum.

  • Bail out on too hard compiler options --coverage, -fprofile-arcs, -fprofile-generate, -fprofile-use, -frepo, -ftest-coverage and -save-temps. Also bail out on @file style options.

  • Errors when using multiple -arch compiler options are now noted as “unsupported compiler option”.

  • -MD/-MMD options without -MT/-MF are now handled correctly.

  • The -finput-charset option is now handled correctly.

  • Added support for -Wp,-MD and -Wp,-MMD options.

  • The compiler options -Xassembler, -b, -G and -V are now correctly recognized as taking an argument.

  • Debug information containing line numbers of predefined and command-line macros (enabled with the compiler option -g3) will now be correct.

  • Corrected LRU cleanup handling of object files.

  • utimes() is now used instead of utime() when available.

  • 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.

  • Freed memory is no longer referenced when compiling a .i/.ii file and falling back to running the real compiler.

  • The test suite is now immune to external values of the CCACHE_* environment variables.

  • Improved detection of recursive invocation.

  • The ccache binary is now not unconditionally stripped when installing.

  • Statistics counters are now correctly updated for -E option failures and internal errors.