Joel Rosdahl [Thu, 1 Oct 2020 11:00:30 +0000 (13:00 +0200)]
Handle missing .gcno file gracefully
GCC ≥9 has changed behavior for -ftest-coverage and --coverage in
combination with -fprofile-dir=dir:
- Without -fprofile-dir=dir the file is placed next to the object file
but with a “.gcno” extension.
- With -fprofile-dir=dir the file is also place next to the object file
(i.e. not in the specified profile directory) but the same style of
name as used for “.gcda” files (full pathname with slashes replaced
with hash characters).
Fix this by:
- Checking if the expected (GCC <9) .gcno file is present. If not, fall
back to running the compiler and increment the “unsupported option”
counter.
- Making sure to perform the above check before copying the object file
to the cache so that a later ccache invocation won’t believe that
there is a result in the cache.
- Improving the copy_file routine to not create the destination file
until it knows that there is a source file to copy from.
Joel Rosdahl [Tue, 1 Sep 2020 14:51:32 +0000 (16:51 +0200)]
Fix debug_prefix_map failure with old objdump versions
“objdump -g” does not list debug info like the “Multiple
-fdebug-prefix-map” test expects when using objdump 2.20, e.g. on CentOS
6. “objdump -W” does however work, and it seems to work for object files
with compressed .debug_str section as well.
Joel Rosdahl [Wed, 20 May 2020 19:26:35 +0000 (21:26 +0200)]
Handle all Intel “-xCODE” compiler options correctly
“CODE” in the Intel compiler’s “-xCODE” option for specifying processor
features seems to always start with an uppercase letter, and since GCC’s
language specifications always are lowercase we can just treat uppercase
codes as an ordinary compiler argument.
Joel Rosdahl [Sun, 5 Jul 2020 18:34:54 +0000 (20:34 +0200)]
Skip “Directory is not hashed if using -gz[=zlib]” tests for GCC 6
The GCC 6 (tested with GCC 6.3) preprocessor includes the current
working directory in the preprocessed output if run with -gz, which
means that there won’t be cache hits between directories, thus failing
the “Directory is not hashed if using -gz[=zlib]” tests. Fix this by
skipping the test if the preprocessor behaves that way.
Joel Rosdahl [Sun, 21 Jun 2020 19:29:04 +0000 (21:29 +0200)]
Remove win32 GetFileNameFromHandle compatibility function
The replacement function seems to be buggy, triggering failures in
x_realpath at least when the unit tests are run in Wine. The real
GetFinalPathNameByHandle function is allegedly supported in Windows
Vista and newer, so let’s just use it.
Joel Rosdahl [Fri, 29 May 2020 18:43:19 +0000 (20:43 +0200)]
Only try to hard link object files to/from the cache
The compiler unlinks the destination object file before writing, but it
apparently doesn’t do that for dependency files. This means that
compilation can corrupt a .d file that shares i-node with a cached .d
file when using the hard link mode. Here is a scenario where this can
happen:
1. There is a test.c which includes test.h.
2. When test.c is compiled, the compiler writes test.d which mentions
test.h and ccache hard links test.d into cache entry 1. test.d and
cache entry 1's .d file now share i-nodes.
3. The include of test.h is removed from test.c.
4. When test.c is compiled again the compiler overwrites test.d with new
content without test.h and ccache hard links test.d into cache entry
2. test.d, cache entry 1 and cache entry 2 now share i-nodes, all of
which contain the new content without test.h.
Since we can’t be sure how the compiler behaves for other types of files
(.dwo, .cov, etc.), only try to to hard link object files.
Joel Rosdahl [Fri, 22 May 2020 19:16:48 +0000 (21:16 +0200)]
Copy directly from cache to destination file instead of via tmp file
ccache copies files to the cache via a temporary file which is then
renamed into place. For simplicity reasons the same file copy function
is used when copying files from the cache as well. This however makes
ccache fail for very long destination filenames.
Fix this by introducing a “via_tmp_file” parameter to copy_file, similar
to how it works on master.
Joel Rosdahl [Thu, 30 Apr 2020 06:29:31 +0000 (08:29 +0200)]
Improve handling of profiling options
Handling of -fprofile-{generate,use}[=path] was implemented in PR #2
(2011). ccache has since then gained support for Clang, which is not
GCC-compatible for -fprofile-{generate,use}[=path]. Furthermore, GCC 9
changed the semantics of -fprofile-{generate,use}=path, making it
incompatible with ccache’s original implementation.
One crucial problem with the implementation is that there is no error
handling when the expected profiling data file cannot be found. This
means that there will be false positives cache hits for Clang and GCC
9+.
Fix this by:
* Checking for different profiling data file locations to handle
different compilers and versions.
* Bailing out if no profiling data file can be found.
Also:
* Implemented support for Clang’s -fprofile-instr-{generate,use}[=path]
options.
* Implemented support for -fauto-profile[=path].
* Removed the conversion of absolute path to the profile directory. 91a2954e says that the directory is rewritten to increase the hit
rate, but I don’t understand how that could be the case.
* Added tests for the profiling options. Exception:
-fauto-profile[=path], since that would require running the perf tool.
Joel Rosdahl [Tue, 24 Mar 2020 20:33:56 +0000 (21:33 +0100)]
Remove incorrect result check in `format`
`format` considers a zero-length result (e.g. from `format("%s", "")`)
to be a fatal error. The check originates from 0a7cea64 where it was
appropriate but become incorrect later when refactoring the original
`x_asprintf2` function to `format`.
I can’t find any call to `format` that would trigger this edge case, but
let’s remove the erroneous check anyway.
Joel Rosdahl [Sun, 22 Mar 2020 13:41:44 +0000 (14:41 +0100)]
Improve name of tmp file in x_unlink
There is no need to generate a unique temporary name in x_unlink since
we don’t care whether the temporary file is clobbered on NFS. The
previous usage of tmp_string() was not quite correct since the returned
string is supposed to be passed to mkstemp, not used as is.
Joel Rosdahl [Sun, 22 Mar 2020 13:30:23 +0000 (14:30 +0100)]
Disable hard link mode when the output object file is /dev/null
When hard link mode is enabled, ccache ≥3.6 unlinks the output file
before writing to it as a workaround for a bug in Clang (#331). This
unfortunately means that /dev/null will be removed when building as root
(don’t do that, BTW) with hard link mode enabled and /dev/null as the
the output file. A similar problem exists if the dependency file is
/dev/null, regardless of hard link mode.
Fix this by not unlinking the output file if it’s /dev/null and by not
copying files to /dev/null at all. (There is no need to handle other
non-regular output files since /dev/null is the only allowed non-regular
output file.)
Joel Rosdahl [Wed, 26 Feb 2020 21:50:12 +0000 (22:50 +0100)]
Rewrite the Windows version of the lockfile routines
Instead of emulating the POSIX version, use the native Windows file API
to create a lockfile. This should mitigate several problems with the old
implementation.
Joel Rosdahl [Tue, 14 Jan 2020 20:30:29 +0000 (21:30 +0100)]
Avoid passing compilation-only options to the preprocessor redux
25e73c1f (“Include compiler-only arguments in the hash”) attempted to
fix a regression in 5d8585b5 (“Don’t pass -Werror and compilation-only
options to the preprocessor”). It succeeded fixing the regression all
right, but it also essentially reverted the essence of 5d8585b5 (#312)
since compiler-only arguments once again are passed to the preprocessor.
Sigh.
Fix this for real and also write a test that proves it.
Joel Rosdahl [Sat, 4 Jan 2020 18:19:01 +0000 (19:19 +0100)]
Make sure to always log a “Result:” line
Fixes #500.
A side effect of this is that read-only cache misses now will update the
“cache miss” statistics counter, which is consistent with the cache hit
cases (which already now update the counters).
The reason for reverting is that the change introduced a nasty bug: the
dependency file will get an incorrect object file location if 1) build
directory != source directory and 2) -MF is not specified explictly by
the user.
Details: The dependency file is created by the preprocessor pass which
does not have access to the final output file name, so the preprocessor
uses the default object location derived from the source file location
instead.
Note that this partly reverts a compatibility improvement for EDG-based
compilers (see issue #460).
It should be possible to pass the dependency arguments to the compiler
instead of the preprocessor to make -MD/-MMD without -MQ work, but
that’s too risky to be done as a bug fix.
Joel Rosdahl [Sun, 29 Dec 2019 18:21:39 +0000 (19:21 +0100)]
Remove the unify mode
The unify mode has not received enough attention and has at least these
bugs:
1. The direct mode doesn’t work if the unify mode is enabled. This is
because the unify mode doesn’t call into process_preprocessed_file
which stores the paths and hashes of included files needed by the
direct mode.
2. The .incbin directive detection has no effect when using the unify
mode. This is again because the unify mode doesn’t use
process_preprocessed_file which is where the .incbin detection takes
place.
3. The unifier’s tokenizer doesn’t understand C++11 raw string literals.
4. The unifier ignores comments, but comments may have semantic meaning
to modern compilers, e.g. “fall through” comments.
Bugs 3 and 4 are fixable by improving the unifier’s tokenization
algorithm, but since it’s a bit tricky it likely won’t be worth the
effort, especially not as a bug fix.
Bugs 1 and 2 are also fixable by unifying the two code paths, but that’s
a non-trivial effort.
In addition to the bugs, I believe that the usefullness of the unify
mode is low:
* It’s only applicable when not using -g.
* It won't be enabled for C++ unless somebody fixes bug 3.
* It can make line numbers in warning messages and __LINE__ expansions
incorrect.
* Since comments should not be ignored, the unify mode can only make a
difference for some types of whitespace changes, like adding or
removing blank lines or changing a+b to a + b. (a + b is already
normalized to a + b by the preprocessor.)
Therefore I’ll just remove the unify mode to fix the bugs.
Joel Rosdahl [Sat, 16 Nov 2019 21:59:33 +0000 (22:59 +0100)]
Always include input file path in direct mode hash
The “file_macro sloppiness” mode is a way of opting out of inclusion of
the input file path in the direct mode hash. This can produce a false
cache hit in the following scenario:
- a/r.h exists.
- a/x.c has #include "r.h".
- b/x.c is identical to a/x.c.
- Compiling a/x.c records a/r.h in the manifest.
- Compiling b/x.c results in a false cache hit since a/x.c and b/x.c
share manifests and a/r.h exists.
Therefore, ditch the file_macro sloppiness mode so that the input file
path is always included in the direct mode hash.
This bug has existed ever since the file_macro sloppiness was introduced
in eb5d9bd3beb5 (ccache 3.0). It has remained undetected since
compilations tend to use .d files and ccache before 3.7.5 added an
implicit “-MQ <output_file_path>” argument, thus in practice including
the output file path in the hash and therefore making manifests unique
when the object file path mirrors the source file path. However, ccache
3.7.5 no longer adds the implicit -MQ option, thus exposing the bug.
Russell King [Thu, 31 Oct 2019 16:30:22 +0000 (16:30 +0000)]
stats: Fix statistics update with full filesystem
The statistics file update does not check for write errors correctly
as stdio files are normally buffered. This means that data can be
written to the stdio buffer but not written out until fclose().
Hence, it is imperative that the fclose() return value is also
checked.
If either fprintf() or fclose() fail, clean up the temporary file,
rather than littering the filesystem with needless temporary files.
Igor Pylypiv [Mon, 10 Jun 2019 20:52:35 +0000 (13:52 -0700)]
Fix possible NULL pointer dereference (#433)
cppcheck:
[src/manifest.c:270] -> [src/manifest.c:269]: (warning)
Either the condition '!errmsg' is redundant or there is possible null pointer
dereference: errmsg.
Joel Rosdahl [Mon, 21 Oct 2019 18:06:22 +0000 (20:06 +0200)]
Don’t fail fatally if temporary cpp_stderr file is missing
If the temporary cpp_stderr file is missing when the compilation command
has finished then either some user removed it or ccache removed it in
clean_up_internal_tempdir (since the compilation took more than hour or
the system clock was adjusted?). In either case, let’s just fall back to
running the real compiler instead of failing fatally.
Joel Rosdahl [Tue, 17 Sep 2019 20:37:57 +0000 (22:37 +0200)]
Include compiler-only arguments in the hash
After 5d8585b5 (#312), arguments that are not considered affecting the
preprocessor output won’t be passed to the preprocessor. -Werror and
-Wno-error are also not passed to the preprocessor so that options not
properly marked as “compiler only” will only trigger warnings, not
errors. This was a workaround for Clang complaining about unused
arguments in the preprocessor step performed by ccache.
However, it also introduced a regression: -Werror and the other options
were excluded from the hash as well. This means that
cc -c file_with_warnings.c
would be cached by ccache, including the warning message. A later
cc -Werror -c file_with_warnings.c
call would then be a cache hit, resulting in a compilation warning
instead of an error.
This commit fixes the problem by also including the compiler-only
arguments in the hash.
Joel Rosdahl [Sun, 15 Sep 2019 19:32:50 +0000 (21:32 +0200)]
Only enable more warnings in dev mode when requested
21ded3ae enabled “more warnings” in dev mode unconditionally, but that
doesn’t play well in dev builds with a Clang version older than the one
used in Travis-CI since the “-Wno-foo” options may be unknown. Instead
of doing feature tests for those options, just enable “more warnings”
when --enable-more-warnings is specified and specify it for Travis-CI
builds.
Joel Rosdahl [Thu, 12 Sep 2019 18:50:46 +0000 (20:50 +0200)]
Support GCC 9’s -gz=[type] option
-gz[=type] neither disables nor enables generation of debug info, so
don’t enable the fallback behavior of hashing the current directory when
seeing -gz[=type] alone.