git/config.mak.dev, branch v2.30.2

Merge branch 'jc/sparse-error-for-developer-build'

2020-11-18T21:32:54Z

"make DEVELOPER=1 sparse" used to run sparse and let it emit warnings; now such warnings will cause an error. * jc/sparse-error-for-developer-build: Makefile: enable -Wsparse-error for DEVELOPER build

Merge branch 'jk/perl-warning'

2020-11-09T22:06:25Z

Dev support. * jk/perl-warning: perl: check for perl warnings while running tests

Merge branch 'jk/no-common'

2020-11-02T21:17:41Z

Dev support to catch a tentative definition of a variable in our C code as an error. * jk/no-common: config.mak.dev: build with -fno-common

Makefile: enable -Wsparse-error for DEVELOPER build

2020-10-31T22:24:40Z

With -Wsparse-error, "make sparse" would fail, instead of just giving a warning message. Signed-off-by: Junio C Hamano

perl: check for perl warnings while running tests

2020-10-22T06:11:48Z

We set "use warnings" in most of our perl code to catch problems. But as the name implies, warnings just emit a message to stderr and don't otherwise affect the program. So our tests are quite likely to miss that warnings are being spewed, as most of them do not look at stderr. We could ask perl to make all warnings fatal, but this is likely annoying for non-developers, who would rather have a running program with a warning than something that refuses to work at all. So instead, let's teach the perl code to respect an environment variable (GIT_PERL_FATAL_WARNINGS) to increase the severity of the warnings. This can be set for day-to-day running if people want to be really pedantic, but the primary use is to trigger it within the test suite. We could also trigger that for every test run, but likewise even the tests failing may be annoying to distro builders, etc (just as -Werror would be for compiling C code). So we'll tie it to a special test-mode variable (GIT_TEST_PERL_FATAL_WARNINGS) that can be set in the environment or as a Makefile knob, and we'll automatically turn the knob when DEVELOPER=1 is set. That should give developers and CI the more careful view without disrupting normal users or packagers. Note that the mapping from the GIT_TEST_* form to the GIT_* form in test-lib.sh is necessary even if they had the same name: the perl scripts need it to be normalized to a perl truth value, and we also have to make sure it's exported (we might have gotten it from the environment, but we might also have gotten it from GIT-BUILD-OPTIONS directly). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

config.mak.dev: build with -fno-common

2020-10-16T15:41:40Z

It's an easy mistake to define a variable in a header with "int x;" when you really meant to only declare the variable as "extern int x;" instead. Clang and gcc will both allow this when building with "-fcommon"; they put these "tentative definitions" in a common block which the linker is able to resolve. This is the default in clang and was the default in gcc until gcc-10, since it helps some legacy code. However, we would prefer not to rely on this because: - using "extern" makes the intent more clear (so it's a style issue, but it's one the compiler can help us catch) - according to the gcc manpage, it may yield a speed and code size penalty So let's build explicitly with -fno-common when the DEVELOPER knob is set, which will let developers using clang and older versions of gcc notice these problems. I didn't bother making this conditional on a particular version of gcc. As far as I know, this option has been available forever in both gcc and clang, so old versions don't need to avoid it. And we already expect gcc and clang options throughout config.mak.dev, so it's unlikely anybody setting the DEVELOPER knob is using anything else. It's a noop on gcc-10, of course, but it's not worth trying to exclude it there. Note that there's nothing to fix in the code; we already don't have any issues here. But if you want to test the patch, you can add a bare "int x;" into cache.h, which will cause the link step to fail. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

repository: enable SHA-256 support by default

2020-07-30T16:16:49Z

Now that we have a complete SHA-256 implementation in Git, let's enable it so people can use it. Remove the ENABLE_SHA256 define constant everywhere it's used. Add tests for initializing a repository with SHA-256. Signed-off-by: brian m. carlson Reviewed-by: Eric Sunshine Signed-off-by: Junio C Hamano

Merge branch 'bc/sha-256-part-1-of-4'

2020-03-27T00:11:20Z

SHA-256 transition continues. * bc/sha-256-part-1-of-4: (22 commits) fast-import: add options for rewriting submodules fast-import: add a generic function to iterate over marks fast-import: make find_marks work on any mark set fast-import: add helper function for inserting mark object entries fast-import: permit reading multiple marks files commit: use expected signature header for SHA-256 worktree: allow repository version 1 init-db: move writing repo version into a function builtin/init-db: add environment variable for new repo hash builtin/init-db: allow specifying hash algorithm on command line setup: allow check_repository_format to read repository format t/helper: make repository tests hash independent t/helper: initialize repository if necessary t/helper/test-dump-split-index: initialize git repository t6300: make hash algorithm independent t6300: abstract away SHA-1-specific constants t: use hash-specific lookup tables to define test constants repository: require a build flag to use SHA-256 hex: add functions to parse hex object IDs in any algorithm hex: introduce parsing variants taking hash algorithms ...

config.mak.dev: re-enable -Wformat-zero-length

2020-02-28T16:39:45Z

We recently triggered some -Wformat-zero-length warnings in the code, but no developers noticed because we suppress that warning in builds with the DEVELOPER=1 Makefile knob set. But we _don't_ suppress them in a non-developer build (and they're part of -Wall). So even though non-developers probably aren't using -Werror, they see the annoying warnings when they build. We've had back and forth discussion over the years on whether this warning is useful or not. In most cases we've seen, it's not true that the call is a mistake, since we're using its side effects (like adding a newline status_printf_ln()) or writing an empty string to a destination which is handled by the function (as in write_file()). And so we end up working around it in the source by passing ("%s", ""). There's more discussion in the subthread starting at: https://lore.kernel.org/git/xmqqtwaod7ly.fsf@gitster.mtv.corp.google.com/ The short of it is that we probably can't just disable the warning for everybody because of portability issues. And ignoring it for developers puts us in the situation we're in now, where non-dev builds are annoyed. Since the workaround is both rarely needed and fairly straight-forward, let's just commit to doing it as necessary, and re-enable the warning. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

repository: require a build flag to use SHA-256

2020-02-24T17:33:21Z

At this point, SHA-256 support is experimental and some behavior may change. To avoid surprising unsuspecting users, require a build flag, ENABLE_SHA256, to allow use of a non-SHA-1 algorithm. Enable this flag by default when the DEVELOPER make flag is set so that contributors can test this case adequately. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano