With 57ec9254eb (docs: introduce document to announce breaking changes,
2024-06-14), we have introduced a new document that tracks upcoming
breaking changes in the Git project. In 2454970930 (BreakingChanges:
early adopter option, 2024-10-11) we have amended the document a bit to
mention that any introduced breaking changes must be accompanied by
logic that allows us to easily enable the breaking change at runtime.
While we already have two breaking changes lined up, neither of them has
such a switch because they predate those instructions.
Introduce the proposed `WITH_BREAKING_CHANGES` preprocessor macro and
wire it up with both our Makefiles and Meson.
Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
---
GIT-BUILD-OPTIONS.in | 1 +
Makefile | 5 +++++
contrib/buildsystems/CMakeLists.txt | 1 +
meson.build | 6 ++++++
meson_options.txt | 2 ++
t/test-lib.sh | 4 ++++
6 files changed, 19 insertions(+)
diff --git a/GIT-BUILD-OPTIONS.in b/GIT-BUILD-OPTIONS.in
index f651116102ae2977622dccd12b199fe7ad65af99..f1d0ecf123031dd13232cc63e100da528bfea16a 100644
--- a/GIT-BUILD-OPTIONS.in
+++ b/GIT-BUILD-OPTIONS.in
@@ -45,3 +45,4 @@ GITWEBDIR=@GITWEBDIR@
USE_GETTEXT_SCHEME=@USE_GETTEXT_SCHEME@
LOCALEDIR=@LOCALEDIR@
BROKEN_PATH_FIX=@BROKEN_PATH_FIX@
+WITH_BREAKING_CHANGES=@WITH_BREAKING_CHANGES@
diff --git a/Makefile b/Makefile
index 06f01149ecf399ae4bb1932188a007948d767283..dc3c980aa7a4f42d27ed72415a636ac82b2a5684 100644
--- a/Makefile
+++ b/Makefile
@@ -2230,6 +2230,10 @@ ifdef FSMONITOR_OS_SETTINGS
COMPAT_OBJS += compat/fsmonitor/fsm-path-utils-$(FSMONITOR_OS_SETTINGS).o
endif
+ifdef WITH_BREAKING_CHANGES
+ BASIC_CFLAGS += -DWITH_BREAKING_CHANGES
+endif
+
ifeq ($(TCLTK_PATH),)
NO_TCLTK = NoThanks
endif
@@ -3187,6 +3191,7 @@ GIT-BUILD-OPTIONS: FORCE
-e "s|@USE_GETTEXT_SCHEME@|\'$(USE_GETTEXT_SCHEME)\'|" \
-e "s|@LOCALEDIR@|\'$(localedir_SQ)\'|" \
-e "s!@BROKEN_PATH_FIX@!\'$(BROKEN_PATH_FIX)\'!" \
+ -e "s|@WITH_BREAKING_CHANGES@|\'$(WITH_BREAKING_CHANGES)\'|" \
GIT-BUILD-OPTIONS.in >$@+
@if grep -q '^[A-Z][A-Z_]*=@.*@$$' $@+; then echo "Unsubstituted build options in $@" >&2 && exit 1; fi
@if cmp $@+ $@ >/dev/null 2>&1; then $(RM) $@+; else mv $@+ $@; fi
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index 49904ca8a93981c514540bad5efa6833ddd14426..63d008892848c20d5937d9a624a480f700b19498 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -1198,6 +1198,7 @@ string(REPLACE "@GITWEBDIR@" "'${GITWEBDIR}'" git_build_options "${git_build_opt
string(REPLACE "@USE_GETTEXT_SCHEME@" "" git_build_options "${git_build_options}")
string(REPLACE "@LOCALEDIR@" "'${LOCALEDIR}'" git_build_options "${git_build_options}")
string(REPLACE "@BROKEN_PATH_FIX@" "" git_build_options "${git_build_options}")
+string(REPLACE "@WITH_BREAKING_CHANGES@" "" git_build_options "${git_build_options}")
if(USE_VCPKG)
string(APPEND git_build_options "PATH=\"$PATH:$TEST_DIRECTORY/../compat/vcbuild/vcpkg/installed/x64-windows/bin\"\n")
endif()
diff --git a/meson.build b/meson.build
index 0dccebcdf16b07650d943e53643f0e09e2975cc9..316cd9326437876828a88d96a1bc93d503199900 100644
--- a/meson.build
+++ b/meson.build
@@ -644,6 +644,12 @@ build_options_config.set('GIT_TEST_UTF8_LOCALE', '')
build_options_config.set_quoted('LOCALEDIR', fs.as_posix(get_option('prefix') / get_option('localedir')))
build_options_config.set('GITWEBDIR', fs.as_posix(get_option('prefix') / get_option('datadir') / 'gitweb'))
+if get_option('breaking_changes')
+ build_options_config.set('WITH_BREAKING_CHANGES', 'YesPlease')
+else
+ build_options_config.set('WITH_BREAKING_CHANGES', '')
+endif
+
if get_option('sane_tool_path') != ''
build_options_config.set_quoted('BROKEN_PATH_FIX', 's|^\# @BROKEN_PATH_FIX@$|git_broken_path_fix "' + get_option('sane_tool_path') + '"|')
else
diff --git a/meson_options.txt b/meson_options.txt
index 32a72139bae870745d9131cc9086a4594826be91..800e518d959c4143812f8840415b99a593667a8d 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -43,6 +43,8 @@ option('sha256_backend', type: 'combo', choices: ['openssl', 'nettle', 'gcrypt',
description: 'The backend used for hashing objects with the SHA256 object format')
# Build tweaks.
+option('breaking_changes', type: 'boolean', value: false,
+ description: 'Enable upcoming breaking changes.')
option('macos_use_homebrew_gettext', type: 'boolean', value: true,
description: 'Use gettext from Homebrew instead of the slightly-broken system-provided one.')
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 62dfcc4aaf959d0cf066d07663d939e14f92485c..6e423f655d35adf5a2d4f8b3a78d9e8c1119caab 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1864,6 +1864,10 @@ test_lazy_prereq CURL '
curl --version
'
+test_lazy_prereq WITHOUT_BREAKING_CHANGES '
+ test -z "$WITH_BREAKING_CHANGES"
+'
+
# SHA1 is a test if the hash algorithm in use is SHA-1. This is both for tests
# which will not work with other hash algorithms and tests that work but don't
# test anything meaningful (e.g. special values which cause short collisions).
--
2.47.1.447.ga7e8429e30.dirty
