Meson detects the path of the target shell via `find_program("sh")`,
which essentially does a lookup via `PATH`. This may easily lead to a
subtly-broken Git distribution when the build host has its shell in a
location that the target host doesn't know about.
Fix the issue by appending "/bin" to the custom program path, which
causes us to prefer "/bin/sh" over a `PATH`-based lookup. While
"/bin/sh" isn't standardized, this path tends to work alright on Linux
and BSD distributions. Furthermore, "/bin/sh" is also the path we pick
in our Makefile by default, which further demonstrates that this shell
fulfills our needs.
Note that we intentionally append, not prepend, to the custom program
path. This is because the program path can be configured by the user via
the `-Dsane_tool_path=` build option, which should take precedence over
any defaults we pick for the user.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git needs to know about a couple of executable paths to pick at runtime.
This includes the system shell, but may also optionally include the Perl
and Python interpreters. Meson detects the location of these paths
automatically via `find_program()`, which does a lookup via the `PATH`
environment variable. As such, it may not be immediately obvious to the
developer which paths have been autodetected.
Improve this by exposing runtime executable paths at setup time.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are added in the Makefile, but not in meson. They probably won't
work well on systems without them.
CMake adds them, but only on non-Windows. Actually, it only performs
compiler checks for hstrerror, but excludes that check on Windows with
the note that it is "incompatible with the Windows build". This seems to
be misleading -- it is not incompatible, it simply doesn't exist. Still,
the compat version should not be used.
I interpret this cmake logic to mean we shouldn't even be checking for
symbol availability on Windows. In addition to making it simple to add
compat definitions, this also probably shaves off a second or two of
configure time on Windows as no compiler check needs to be performed.
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Nowhere in the codebase do we otherwise check for strerror. Nowhere in
the codebase do we make use of -DNO_STRERROR. `strerror` is not a
networking function at all.
We do utilize `hstrerror` though, which is a networking function we
should have been checking here.
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As evidenced in config.mak.uname and configure.ac, there are various
possible scenarios where these libraries are default-enabled in the
build, which mainly boils down to: SunOS. -lresolv is simply not the
only library that, when it exists, probably needs to be linked to for
networking.
Check for and add -lnsl -lsocket as well.
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On Solaris, sys/sysinfo.h is a completely different file and doesn't
resemble the linux file at all. There is also a sysinfo() function, but
it takes a totally different call signature, which asks for:
- the field you wish to receive
- a `char *buf` to copy the data to
and is very useful IFF you want to know, say, the hardware provider. Or,
get *specific* fields from uname(2).
https://docs.oracle.com/cd/E86824_01/html/E54765/sysinfo-2.html
It is surely possible to do this manually via `sysconf(3)` without the
nice API. I can't find anything more direct. Either way, I'm not very
attached to Solaris, so someone who cares can add it. Either way, it's
wrong to assume that sysinfo.h contains what we are looking for.
Check that sysinfo.h defines the struct we actually utilize in
builtins/gc.c, which will correctly fail on systems that don't have it.
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is deprecated and removed in SUS v3 / POSIX 2001, so various systems
may not include it. Solaris, in particular, carefully refrains from
defining it except inside of a maze of `#ifdef` to make sure you have
kept your nose clean and only used it in code that *targets* SUS v2 or
earlier.
config.mak.uname defines this automatically, though only for QNX.
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is repetitive logic. We either want to use some -lc function, or if
it is not available we define it as -DNO_XXX and usually (but not
always) provide some custom compatibility impl instead.
Checking the intent of each block when reading through the file is slow
and not very DRY. Switch to taking an array of checkable functions
instead.
Not all functions are straightforward to move, since different macro
prefixes are used.
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various build tweaks, including CSPRNG selection on some platforms.
* rj/build-tweaks:
config.mak.uname: set CSPRNG_METHOD to getrandom on Linux
config.mak.uname: add arc4random to the cygwin build
config.mak.uname: add sysinfo() configuration for cygwin
builtin/gc.c: correct RAM calculation when using sysinfo
config.mak.uname: add clock_gettime() to the cygwin build
config.mak.uname: add HAVE_GETDELIM to the cygwin section
config.mak.uname: only set NO_REGEX on cygwin for v1.7
config.mak.uname: add a note about NO_STRLCPY for Linux
Makefile: remove NEEDS_LIBRT build variable
meson.build: set default help format to html on windows
meson.build: only set build variables for non-default values
Makefile: only set some BASIC_CFLAGS when RUNTIME_PREFIX is set
meson.build: remove -DCURL_DISABLE_TYPECHECK
Code clean-up.
* ps/object-file-cleanup:
object-store: merge "object-store-ll.h" and "object-store.h"
object-store: remove global array of cached objects
object: split out functions relating to object store subsystem
object-file: drop `index_blob_stream()`
object-file: split up concerns of `HASH_*` flags
object-file: split out functions relating to object store subsystem
object-file: move `xmmap()` into "wrapper.c"
object-file: move `git_open_cloexec()` to "compat/open.c"
object-file: move `safe_create_leading_directories()` into "path.c"
object-file: move `mkdir_in_gitdir()` into "path.c"
The 'hdr-check' target in Meson and makefile is used to check if headers
can be compiled individually. The naming however isn't readable as 'hdr'
is not a common shortforme for 'header', neither is it an abbreviation.
Let's introduce 'check-headers' as an alternative target for 'hdr-check'
and add a `TODO` to deprecate the latter after 2 releases. Since this
is an internal tool, we can use a shorter deprecation cycle.
Change existing usage of 'hdr-check' in 'ci/run-static-analysis.sh' to
also use 'check-headers'.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Makefile supports a target called 'hdr-check', which checks if
individual header files can be independently compiled. Let's port this
functionality to Meson, our new build system too. The implementation
resembles that of the Makefile and provides the same check.
Since meson builds are out-of-tree, header dependencies are not
automatically met. So unlike the Makefile version, we also need to add
the required dependencies.
Also add the 'xdiff/' dir to the list of 'third_party_sources' as those
headers must be skipped from the checks too. This also skips the folder
from the 'coccinelle' checks, this is okay, since this code is an
external dependency.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'third_party_sources' variable was moved to the root 'meson.build'
file in the previous commit. The variable is actually used to exclude
third party sources, so rename it accordingly to 'third_party_excludes'
to avoid confusion. While here, remove a duplicate from the list.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Meson build for coccinelle static analysis lists all headers to
analyse. Due to the way Meson exports variables between subdirs, this
variable is also available in the root Meson build.
An upcoming commit, will add a new check complimenting 'hdr-check' in
the Makefile. This would require the list of headers. So move the
'coccinelle_headers' to the root Meson build and rename it to 'headers',
remove the root path being appended to each header and retain that in
the coccinelle Meson build since it is specific to the coccinelle build.
Also move the 'third_party_sources' variable to the root Meson build
since it is also a dependency for the 'headers' variable. This also
makes it easier to understand as the variable is now propagated from the
top level to the bottom.
While 'headers_to_check' is only computed when we have a repository and
the 'git' executable is present, the variable itself is exposed as an
empty array. This allows dependencies in upcoming commits to simply
check for length of the array and not worry about dependencies required
to actually populate the array.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove remnants of the recursive merge strategy backend, which was
superseded by the ort merge strategy.
* en/merge-recursive-debug:
builtin/{merge,rebase,revert}: remove GIT_TEST_MERGE_ALGORITHM
tests: remove GIT_TEST_MERGE_ALGORITHM and test_expect_merge_algorithm
merge-recursive.[ch]: thoroughly debug these
merge, sequencer: switch recursive merges over to ort
sequencer: switch non-recursive merges over to ort
merge-ort: enable diff-algorithms other than histogram
builtin/merge-recursive: switch to using merge_ort_generic()
checkout: replace merge_trees() with merge_ort_nonrecursive()
The build variable DEFAULT_HELP_FORMAT has an appropriate default
('man') set in the code, so there is no need to pass the -Define on
the compiler command-line, unless the build requires a non-standard
value.
In addition, on windows the make build overrides the default help
format to 'html', rather than 'man', in the 'config.mak.uname' file.
In order to suppress the -Define on the C compiler command-line, only
add the -Define to the 'libgit_c_args' variable when the requested
value is not the standard 'man'. In order to override the default value
on windows, add a 'platform' value to the 'default_help_format' combo
option and set it as the default choice. When this option is set to
'platform', use the 'host_machine.system()' method call to determine the
appropriate default value for the host system.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some preprocessor -Defines have defaults set in the source code when
they have not been provided to the C compiler. In this case, there is
no need to pass them on the command-line, unless the build requires a
non-standard value.
The build variables for DEFAULT_EDITOR and DEFAULT_PAGER have appropriate
defaults ('vi' and 'less') set in the code. Add the preprocessor -Defines
to the 'libgit_c_args' only if the values set with the corresponding
'options' are different to these standard values.
Also, the 'git-var' documentation contains some conditional text which
documents the chosen compiled in value, which would not read well for
the standard values. Similar to the above, only add the corresponding
'-a' attribute arguments to the 'asciidoc_common_options' variable, if
the values set in the 'options' are different to these standard values.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 9371322a60 ("sparse: suppress some \"using sizeof on a function\"
warnings", 2013-10-06) used target-specific variable assignments to add
-DCURL_DISABLE_TYPECHECK to SPARSE_FLAGS for each of the files affected
by the "typecheck-gcc.h" warnings. (http-push.c, http.c, http-walker.c
and remote-curl.c).
These warnings are only issued by sparse, and not by gcc, so we do not
want to disable the 'type checking' for non-sparse targets. The meson
build does not provide any sparse targets, so there is no need to use
the CURL_DISABLE_TYPECHECK preprocessor flag with the c compiler.
In order to re-enable the curl 'type checking' in the meson build, remove
the assignment of -DCURL_DISABLE_TYPECHECK to libgit_c_args.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"make test" used to have a hard dependency on (basic) Perl; tests
have been rewritten help environment with NO_PERL test the build as
much as possible.
* ps/test-wo-perl-prereq:
t5703: refactor test to not depend on Perl
t5316: refactor `max_chain()` to not depend on Perl
t0210: refactor trace2 scrubbing to not use Perl
t0021: refactor `generate_random_characters()` to not depend on Perl
t/lib-httpd: refactor "one-time-perl" CGI script to not depend on Perl
t/lib-t6000: refactor `name_from_description()` to not depend on Perl
t/lib-gpg: refactor `sanitize_pgp()` to not depend on Perl
t: refactor tests depending on Perl for textconv scripts
t: refactor tests depending on Perl to print data
t: refactor tests depending on Perl substitution operator
t: refactor tests depending on Perl transliteration operator
Makefile: stop requiring Perl when running tests
meson: stop requiring Perl when tests are enabled
t: adapt existing PERL prerequisites
t: introduce PERL_TEST_HELPERS prerequisite
t: adapt `test_readlink()` to not use Perl
t: adapt `test_copy_bytes()` to not use Perl
t: adapt character translation helpers to not use Perl
t: refactor environment sanitization to not use Perl
t: skip chain lint when PERL_PATH is unset
Random build fixes.
* ps/misc-build-fixes:
ci: use Visual Studio for win+meson job on GitHub Workflows
meson: distinguish build and target host binaries
meson: respect 'tests' build option in contrib
gitweb: fix generation of "gitweb.js"
meson: fix handling of '-Dcurl=auto'
The "cmd-list.perl" script is used to extract the list of commands part
of a specific category and extracts the description of each command from
its respective manpage. The generated output is then included in git(1)
to list all Git commands.
The script is written in Perl. Refactor it to use shell scripting
exclusively so that we can get rid of the mandatory dependency on Perl
to build our documentation.
The converted script is slower compared to its Perl implementation. But
by being careful and not spawning external commands in `format_one ()`
we can mitigate the performance hit to a reasonable level:
Benchmark 1: Perl
Time (mean ± σ): 10.3 ms ± 0.2 ms [User: 7.0 ms, System: 3.3 ms]
Range (min … max): 10.0 ms … 11.1 ms 200 runs
Benchmark 2: Shell
Time (mean ± σ): 74.4 ms ± 0.4 ms [User: 48.6 ms, System: 24.7 ms]
Range (min … max): 73.1 ms … 75.5 ms 200 runs
Summary
Perl ran
7.23 ± 0.13 times faster than Shell
While a sevenfold slowdown is significant, the benefit of not requiring
Perl for a fully-functioning Git installation outweighs waiting a couple
of milliseconds longer during the build process.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up.
* js/comma-semicolon-confusion:
detect-compiler: detect clang even if it found CUDA
clang: warn when the comma operator is used
compat/regex: explicitly mark intentional use of the comma operator
wildmatch: avoid using of the comma operator
diff-delta: avoid using the comma operator
xdiff: avoid using the comma operator unnecessarily
clar: avoid using the comma operator unnecessarily
kwset: avoid using the comma operator unnecessarily
rebase: avoid using the comma operator unnecessarily
remote-curl: avoid using the comma operator unnecessarily
Fix lockfile contention in reftable code on Windows.
* ps/mingw-creat-excl-fix:
compat/mingw: fix EACCESS when opening files with `O_CREAT | O_EXCL`
meson: fix compat sources when compiling with MSVC
The object layer has been updated to take an explicit repository
instance as a parameter in more code paths.
* ps/object-wo-the-repository:
hash: stop depending on `the_repository` in `null_oid()`
hash: fix "-Wsign-compare" warnings
object-file: split out logic regarding hash algorithms
delta-islands: stop depending on `the_repository`
object-file-convert: stop depending on `the_repository`
pack-bitmap-write: stop depending on `the_repository`
pack-revindex: stop depending on `the_repository`
pack-check: stop depending on `the_repository`
environment: move access to "core.bigFileThreshold" into repo settings
pack-write: stop depending on `the_repository` and `the_hash_algo`
object: stop depending on `the_repository`
csum-file: stop depending on `the_repository`
* ps/test-wo-perl-prereq:
t5703: refactor test to not depend on Perl
t5316: refactor `max_chain()` to not depend on Perl
t0210: refactor trace2 scrubbing to not use Perl
t0021: refactor `generate_random_characters()` to not depend on Perl
t/lib-httpd: refactor "one-time-perl" CGI script to not depend on Perl
t/lib-t6000: refactor `name_from_description()` to not depend on Perl
t/lib-gpg: refactor `sanitize_pgp()` to not depend on Perl
t: refactor tests depending on Perl for textconv scripts
t: refactor tests depending on Perl to print data
t: refactor tests depending on Perl substitution operator
t: refactor tests depending on Perl transliteration operator
Makefile: stop requiring Perl when running tests
meson: stop requiring Perl when tests are enabled
t: adapt existing PERL prerequisites
t: introduce PERL_TEST_HELPERS prerequisite
t: adapt `test_readlink()` to not use Perl
t: adapt `test_copy_bytes()` to not use Perl
t: adapt character translation helpers to not use Perl
t: refactor environment sanitization to not use Perl
t: skip chain lint when PERL_PATH is unset
While we have the "object-store.h" header, most of the functionality for
object stores is actually hosted in "object-file.c". This makes it hard
to find relevant functions and causes us to mix up concerns.
Split out functions relating to the object store subsystem into a new
"object-store.c" file.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `git_open_cloexec()` wrapper function provides the ability to open a
file with `O_CLOEXEC` in a platform-agnostic way. This function is
provided by "object-file.c" even though it is not specific to the object
subsystem at all.
Move the file into "compat/open.c". This file already exists before this
commit, but has only been compiled conditionally depending on whether or
not open(3p) may return EINTR. With this change we now unconditionally
compile the object, but wrap `git_open_with_retry()` in an ifdef.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/object-wo-the-repository:
hash: stop depending on `the_repository` in `null_oid()`
hash: fix "-Wsign-compare" warnings
object-file: split out logic regarding hash algorithms
delta-islands: stop depending on `the_repository`
object-file-convert: stop depending on `the_repository`
pack-bitmap-write: stop depending on `the_repository`
pack-revindex: stop depending on `the_repository`
pack-check: stop depending on `the_repository`
environment: move access to "core.bigFileThreshold" into repo settings
pack-write: stop depending on `the_repository` and `the_hash_algo`
object: stop depending on `the_repository`
csum-file: stop depending on `the_repository`
As a wise man once told me, "Deleted code is debugged code!" So, move
the functions that are shared between merge-recursive and merge-ort from
the former to the latter, and then debug the remainder of
merge-recursive.[ch].
Joking aside, merge-ort was always intended to replace merge-recursive.
It has numerous advantages over merge-recursive (operates much faster,
can operate without a worktree or index, and fixes a number of known
bugs and suboptimal merges). Since we have now replaced all callers of
merge-recursive with equivalent functions from merge-ort, move the
shared functions from the former to the latter, and delete the remainder
of merge-recursive.[ch].
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `struct reftable_reader` subsystem encapsulates a table that has
been read from the disk. As such, the current name of that structure is
somewhat hard to understand as it only talks about the fact that we read
something from disk, without really giving an indicator _what_ that is.
Furthermore, this naming schema doesn't really fit well into how the
other structures are named: `reftable_merged_table`, `reftable_stack`,
`reftable_block` and `reftable_record` are all named after what they
encapsulate.
Rename the subsystem to `reftable_table`, which directly gives a hint
that the data structure is about handling the individual tables part of
the stack.
While this change results in a lot of churn, it prepares for us exposing
the APIs to third-party callers now that the reftable library is a
standalone library that can be linked against by other projects.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Perl interpreter used to be a strict dependency for running our test
suite. This requirement is explicit in the Meson build system, where we
require Perl to be present unless tests have been disabled.
With the preceding commits we have loosened this restriction so that it
is now possible to run tests when Perl is unavailable. Loosen the above
requirement accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Almost all of the tools we discover during the build process need to be
native programs. There are only a handful of exceptions, which typically
are programs whose paths we need to embed into the resulting executable
so that they can be found on the target system when Git executes. While
this distinction typically doesn't matter, it does start to matter when
considering cross-compilation where the build and target machines are
different.
Meson supports cross-compilation via so-called machine files. These
machine files allow the user to override parameters for the build
machine, but also for the target machine when cross-compiling. Part of
the machine file is a section that allows the user to override the
location where binaries are to be found in the target system. The
following machine file would for example override the path of the POSIX
shell:
[binaries]
sh = '/usr/xpg4/bin/sh'
It can be handed over to Meson via `meson setup --cross-file`.
We do not handle this correctly right now though because we don't know
to distinguish binaries for the build and target hosts at all. Address
this by explicitly passing the `native:` parameter to `find_program()`:
- When set to `true`, we get binaries discovered on the build host.
- When set to `false`, we get either the path specified in the
machine file. Or, if no machine file exists or it doesn't specify
the binary path, then we fall back to the binary discovered on the
build host.
As mentioned, only a handful of binaries are not native: only the system
shell, Python and Perl need to be treated specially here.
Reported-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "curl" option controls whether or not a couple of features that
depend on curl shall be included. Most importantly, these features
include the HTTP remote helpers, which are rather quintessential for a
well-functioning Git installation. So while the dependency can in theory
be dropped, most users wouldn't consider the resulting installation to
be fully functional.
The "curl" option is defined as a feature, which means that it can be
"enabled", "disabled" or "auto", which has the effect that the feature
will be enabled if the dependency itself has been found. While most of
the other features have "auto" as default value, the "curl" option is
set to "enabled" by default due to it being so important. Consequently,
autoconfiguration of Git will fail by default if the library cannot be
found.
There is a bug though with how we handle the option in case the user
overrides the feature with `meson setup -Dcurl=auto`: while we will try
to find the library in that case, we won't ever use it because we later
on check for `get_option('curl').enabled()` when deciding whether or not
we want to build dependent sources. But `enabled()` only returns true if
the option has the value "enabled", for "auto" it will return false.
Fix the issue by instead checking for `curl.found()`, which is only true
if the library has been found. And as we only try to find the library
when `get_option('curl')` returns "true" or "auto" this is exactly what
we want.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enable -Wunreachable-code for developer builds.
* jk/use-wunreachable-code-for-devs:
config.mak.dev: enable -Wunreachable-code
git-compat-util: add NOT_CONSTANT macro and use it in atfork_prepare()
run-command: use errno to check for sigfillset() error
When compiling Git using `clang`, the `-Wcomma` option can be used to
warn about code using the comma operator (because it is typically
unintentional and wants to use the semicolon instead).
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In our compat library we have both "msvc.c" and "mingw.c". The former is
mostly a thin wrapper around the latter as it directly includes it, but
it has a couple of extra headers that aren't included in "mingw.c" and
is expected to be used with the Visual Studio compiler toolchain.
While our Makefile knows to pick up the correct file depending on
whether or not the Visual Studio toolchain is used, we don't do the same
with Meson. Fix this.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Having the compiler point out unreachable code can help avoid bugs, like
the one discussed in:
https://lore.kernel.org/git/20250307195057.GA3675279@coredump.intra.peff.net/
In that case it was found by Coverity, but finding it earlier saves
everybody time and effort.
We can use -Wunreachable-code to get some help from the compiler here.
Interestingly, this is a noop in gcc. It was a real warning up until gcc
4.x, when it was removed for being too flaky, but they left the
command-line option to avoid breaking users. See:
https://stackoverflow.com/questions/17249934/why-does-gcc-not-warn-for-unreachable-code
However, clang does implement this option, and it finds the case
mentioned above (and no other cases within the code base). And since we
run clang in several of our CI jobs, that's enough to get an early
warning of breakage.
We could enable it only for clang, but since gcc is happy to ignore it,
it's simpler to just turn it on for all developer builds.
Signed-off-by: Jeff King <peff@peff.net>
[jc: squashed meson.build change sent by Patrick]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our hope is that the number of code paths that falsely trigger
warnings with the -Wunreachable-code compilation option are small,
and they can be worked around case-by-case basis, like we just did
in the previous commit. If we need such a workaround a bit more
often, however, we may benefit from a more generic and descriptive
facility that helps document the cases we need such workarounds.
Side note: if we need the workaround all over the place, it
simply means -Wunreachable-code is not a good tool for us to
save engineering effort to catch mistakes. We are still
exploring if it helps us, so let's assume that it is not the
case.
Introduce NOT_CONSTANT() macro, with which, the developer can tell
the compiler:
Do not optimize this expression out, because, despite whatever
you are told by the system headers, this expression should *not*
be treated as a constant.
and use it as a replacement for the workaround we used that was
somewhat specific to the sigfillset case. If the compiler already
knows that the call to sigfillset() cannot fail on a particular
platform it is compiling for and declares that the if() condition
would not hold, it is plausible that the next version of the
compiler may learn that sigfillset() that never fails would not
touch errno and decide that in this sequence:
errno = 0;
sigfillset(&all)
if (errno)
die_errno("sigfillset");
the if() statement will never trigger. Marking that the value
returned by sigfillset() cannot be a constant would document our
intention better and would not break with such a new version of
compiler that is even more "clever". With the marco, the above
sequence can be rewritten:
if (NOT_CONSTANT(sigfillset(&all)))
die_errno("sigfillset");
which looks almost like other innocuous annotations we have,
e.g. UNUSED.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `perl` variable in meson.build is assigned to a program lookup,
which may have the value "not-found object" if configuring with
`-Dperl=disabled`.
There is already a list of other cases where we do need a perl command,
even when not building perl bindings. Building documentation should be
one of those cases, but was missing from the list. Add it.
Fixes:
```
$ meson setup builddir/ -Ddocs=man -Dperl=disabled -Dtests=false
[...]
Documentation/meson.build:308:22: ERROR: Tried to use not-found external program in "command"
```
Bug: https://bugs.gentoo.org/949247
Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We continue to compile the git-pack-redundant(1) builtin with Meson when
breaking changes are enabled even though we ultimately don't expose this
command at all. This is mostly harmless, but given that the intent of
the build option is to be as close as possible to the state where the
breaking change has been fully implemented this isn't optimal either.
Improve the situation by not compiling the builtin when breaking changes
are enabled.
Based-on-patch-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While Meson already supports the `-Dbreaking_changes=true` option, it
only wires up the build option that propagates into the tests. The build
option is only used for our tests to enable the `WITH_BREAKING_CHANGES`
prerequisite though, and does not influence the code that is actually
being built.
The omission went unnoticed because we only have tests right now that
get disabled when breaking changes are enabled, but not the other way
round. In other words, we don't have any tests that verify that breaking
changes behave as expected.
Fix the build issue by setting the `WITH_BREAKING_CHANGES` preprocessor
macro when breaking changes are enabled. Note that the `libgit_c_args`
array is defined after the current spot where we handle the option, so
to not have multiple sites where we handle it we instead move it after
the array has been defined.
Based-on-patch-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While we have a "hash.h" header, the actual implementation of the
subsystem is hosted by "object-file.c". This makes it harder than
necessary to find the actual implementation of the hash subsystem and
intermingles the different concerns with one another.
Split out the implementation of hash algorithms into a new, separate
"hash.c" file.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 904339edbd (Introduce support for the Meson build system,
2024-12-06) the `meson.build` file was introduced, adding also a
Windows-specific list of source files. This list was obviously meant to
be sorted alphabetically, but there is one mistake. Let's fix that.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Assorted fixes and improvements to the build procedure based on
meson.
* ps/build-meson-fixes-0130:
gitlab-ci: restrict maximum number of link jobs on Windows
meson: consistently use custom program paths to resolve programs
meson: fix overwritten `git` variable
meson: prevent finding sed(1) in a loop
meson: improve handling of `sane_tool_path` option
meson: improve PATH handling
meson: drop separate version library
meson: stop linking libcurl into all executables
meson: introduce `libgit_curl` dependency
meson: simplify use of the common-main library
meson: inline the static 'git' library
meson: fix OpenSSL fallback when not explicitly required
meson: fix exec path with enabled runtime prefix
Through git-diff(1), a single diff can be generated from a pair of blob
revisions directly. Unfortunately, there is not a mechanism to compute
batches of specific file pair diffs in a single process. Such a feature
is particularly useful on the server-side where diffing between a large
set of changes is not feasible all at once due to timeout concerns.
To facilitate this, introduce git-diff-pairs(1) which acts as a backend
passing its NUL-terminated raw diff format input from stdin through diff
machinery to produce various forms of output such as patch or raw.
The raw format was originally designed as an interchange format and
represents the contents of the diff_queued_diff list making it possible
to break the diff pipeline into separate stages. For example,
git-diff-tree(1) can be used as a frontend to compute file pairs to
queue and feed its raw output to git-diff-pairs(1) to compute patches.
With this, batches of diffs can be progressively generated without
having to recompute renames or retrieve object context. Something like
the following:
git diff-tree -r -z -M $old $new |
git diff-pairs -p -z
should generate the same output as `git diff-tree -p -M`. Furthermore,
each line of raw diff formatted input can also be individually fed to a
separate git-diff-pairs(1) process and still produce the same output.
Based-on-patch-by: Jeff King <peff@peff.net>
Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're assigning the `git` variable in three places:
- In "meson.build" to store the external Git executable.
- In "meson.build" to store the compiled Git executable.
- In "Documentation/meson.build" to store the external Git executable,
a second time.
The last case is only needed because we overwrite the original variable
with the built version. Rename the variable used for the built Git
executable so that we don't have to resolve the external Git executable
multiple times.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
