From 4638e8806e3a1c5550b9ee3a1201e79cc519b85e Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Fri, 6 Dec 2024 14:24:36 +0100
Subject: Makefile: use common template for GIT-BUILD-OPTIONS

The "GIT-BUILD-OPTIONS" file is generated by our build systems to
propagate built-in features and paths to our tests. The generation is
done ad-hoc, where both our Makefile and the CMake build instructions
simply echo a bunch of strings into the file. This makes it very hard to
figure out what variables are expected to exist and what format they
have, and the written variables can easily get out of sync between build
systems.

Introduce a new "GIT-BUILD-OPTIONS.in" template to address this issue.
This has multiple advantages:

  - It demonstrates which built options exist in the first place.

  - It can serve as a spot to document the build options.

  - Some build systems complain when not all variables could be
    substituted, alerting us of mismatches. Others don't, but if we
    forgot to substitute such variables we now have a bogus string that
    will likely cause our tests to fail, if they have any meaning in the
    first place.

Backfill values that we didn't yet set in our CMake build instructions.
While at it, remove the `SUPPORTS_SIMPLE_IPC` variable that we only set
up in CMake as it isn't used anywhere.

This change requires us to adapt the setup of TEST_OUTPUT_DIRECTORY in
"test-lib.sh" such that it does not get overwritten after sourcing when
it has been set up via the environment. This is the only instance I
could find where we rely on ordering on variables.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 426036b33a..20012f6f47 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -35,12 +35,6 @@ else
 	# needing to exist.
 	TEST_DIRECTORY=$(cd "$TEST_DIRECTORY" && pwd) || exit 1
 fi
-if test -z "$TEST_OUTPUT_DIRECTORY"
-then
-	# Similarly, override this to store the test-results subdir
-	# elsewhere
-	TEST_OUTPUT_DIRECTORY=$TEST_DIRECTORY
-fi
 GIT_BUILD_DIR="${TEST_DIRECTORY%/t}"
 if test "$TEST_DIRECTORY" = "$GIT_BUILD_DIR"
 then
@@ -92,6 +86,15 @@ export LSAN_OPTIONS
 prepend_var UBSAN_OPTIONS : $GIT_SAN_OPTIONS
 export UBSAN_OPTIONS
 
+# The TEST_OUTPUT_DIRECTORY will be overwritten via GIT-BUILD-OPTIONS. So in
+# case the caller has manually set up this variable via the environment we must
+# make sure to not overwrite that value, and thus we save it into
+# TEST_OUTPUT_DIRECTORY_OVERRIDE here.
+if test -n "$TEST_OUTPUT_DIRECTORY" && test -z "$TEST_OUTPUT_DIRECTORY_OVERRIDE"
+then
+	TEST_OUTPUT_DIRECTORY_OVERRIDE=$TEST_OUTPUT_DIRECTORY
+fi
+
 if test ! -f "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
 then
 	echo >&2 'error: GIT-BUILD-OPTIONS missing (has Git been built?).'
@@ -100,6 +103,13 @@ fi
 . "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
 export PERL_PATH SHELL_PATH
 
+if test -z "$TEST_OUTPUT_DIRECTORY"
+then
+	# Similarly, override this to store the test-results subdir
+	# elsewhere
+	TEST_OUTPUT_DIRECTORY=$TEST_DIRECTORY
+fi
+
 # In t0000, we need to override test directories of nested testcases. In case
 # the developer has TEST_OUTPUT_DIRECTORY part of his build options, then we'd
 # reset this value to instead contain what the developer has specified. We thus
-- 
cgit v1.3


From 7e0730c8baaac43fcf0366e686066ec2c1fc2f31 Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Fri, 6 Dec 2024 14:24:56 +0100
Subject: t: better support for out-of-tree builds

Our in-tree builds used by the Makefile use various different build
directories scattered around different locations. The paths to those
build directories have to be propagated to our tests such that they can
find the contained files. This is done via a mixture of hardcoded paths
in our test library and injected variables in our bin-wrappers or
"GIT-BUILD-OPTIONS".

The latter two mechanisms are preferable over using hardcoded paths. For
one, we have all paths which are subject to change stored in a small set
of central files instead of having the knowledge of build paths in many
files. And second, it allows build systems which build files elsewhere
to adapt those paths based on their own needs. This is especially nice
in the context of build systems that use out-of-tree builds like CMake
or Meson.

Remove hardcoded knowledge of build paths from our test library and move
it into our bin-wrappers and "GIT-BUILD-OPTIONS".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 GIT-BUILD-OPTIONS.in                |  5 +++++
 Makefile                            |  9 +++++++++
 bin-wrappers/wrap-for-bin.sh        | 11 ++++++-----
 contrib/buildsystems/CMakeLists.txt |  8 ++++++++
 t/lib-gettext.sh                    |  4 ++--
 t/t7609-mergetool--lib.sh           |  2 +-
 t/test-lib.sh                       |  6 +++---
 7 files changed, 34 insertions(+), 11 deletions(-)

(limited to 't/test-lib.sh')

diff --git a/GIT-BUILD-OPTIONS.in b/GIT-BUILD-OPTIONS.in
index 9b95a6b3ee..f651116102 100644
--- a/GIT-BUILD-OPTIONS.in
+++ b/GIT-BUILD-OPTIONS.in
@@ -35,6 +35,11 @@ GIT_PERF_MAKE_COMMAND=@GIT_PERF_MAKE_COMMAND@
 GIT_INTEROP_MAKE_OPTS=@GIT_INTEROP_MAKE_OPTS@
 GIT_TEST_INDEX_VERSION=@GIT_TEST_INDEX_VERSION@
 GIT_TEST_PERL_FATAL_WARNINGS=@GIT_TEST_PERL_FATAL_WARNINGS@
+GIT_TEST_TEXTDOMAINDIR=@GIT_TEST_TEXTDOMAINDIR@
+GIT_TEST_POPATH=@GIT_TEST_POPATH@
+GIT_TEST_TEMPLATE_DIR=@GIT_TEST_TEMPLATE_DIR@
+GIT_TEST_GITPERLLIB=@GIT_TEST_GITPERLLIB@
+GIT_TEST_MERGE_TOOLS_DIR=@GIT_TEST_MERGE_TOOLS_DIR@
 RUNTIME_PREFIX=@RUNTIME_PREFIX@
 GITWEBDIR=@GITWEBDIR@
 USE_GETTEXT_SCHEME=@USE_GETTEXT_SCHEME@
diff --git a/Makefile b/Makefile
index e1ae562760..c4b9d2801a 100644
--- a/Makefile
+++ b/Makefile
@@ -3176,6 +3176,11 @@ GIT-BUILD-OPTIONS: FORCE
 		-e "s|@GIT_INTEROP_MAKE_OPTS@|\'$(GIT_INTEROP_MAKE_OPTS)\'|" \
 		-e "s|@GIT_TEST_INDEX_VERSION@|\'$(GIT_TEST_INDEX_VERSION)\'|" \
 		-e "s|@GIT_TEST_PERL_FATAL_WARNINGS@|\'$(GIT_TEST_PERL_FATAL_WARNINGS)\'|" \
+		-e "s|@GIT_TEST_TEXTDOMAINDIR@|\'$(shell pwd)/po/build/locale\'|" \
+		-e "s|@GIT_TEST_POPATH@|\'$(shell pwd)/po\'|" \
+		-e "s|@GIT_TEST_TEMPLATE_DIR@|\'$(shell pwd)/templates/blt\'|" \
+		-e "s|@GIT_TEST_GITPERLLIB@|\'$(shell pwd)/perl/build/lib\'|" \
+		-e "s|@GIT_TEST_MERGE_TOOLS_DIR@|\'$(shell pwd)/mergetools\'|" \
 		-e "s|@RUNTIME_PREFIX@|\'$(RUNTIME_PREFIX_OPTION)\'|" \
 		-e "s|@GITWEBDIR@|\'$(gitwebdir_SQ)\'|" \
 		-e "s|@USE_GETTEXT_SCHEME@|\'$(USE_GETTEXT_SCHEME)\'|" \
@@ -3205,6 +3210,10 @@ all:: $(TEST_PROGRAMS) $(test_bindir_programs) $(UNIT_TEST_PROGS) $(CLAR_TEST_PR
 $(test_bindir_programs): bin-wrappers/%: bin-wrappers/wrap-for-bin.sh
 	$(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
 	     -e 's|@BUILD_DIR@|$(shell pwd)|' \
+	     -e 's|@GIT_TEXTDOMAINDIR@|$(shell pwd)/po/build/locale|' \
+	     -e 's|@GITPERLLIB@|$(shell pwd)/perl/build/lib|' \
+	     -e 's|@MERGE_TOOLS_DIR@|$(shell pwd)/mergetools|' \
+	     -e 's|@TEMPLATE_DIR@|$(shell pwd)/templates/blt|' \
 	     -e 's|@PROG@|$(shell pwd)/$(patsubst test-%,t/helper/test-%,$(@F))$(if $(filter-out $(BINDIR_PROGRAMS_NO_X),$(@F)),$(X),)|' < $< > $@ && \
 	chmod +x $@
 
diff --git a/bin-wrappers/wrap-for-bin.sh b/bin-wrappers/wrap-for-bin.sh
index 2feaec81f2..4b658ffd2d 100755
--- a/bin-wrappers/wrap-for-bin.sh
+++ b/bin-wrappers/wrap-for-bin.sh
@@ -4,21 +4,22 @@
 # to run test suite against sandbox, but with only bindir-installed
 # executables in PATH.  The Makefile copies this into various
 # files in bin-wrappers, substituting
-# @BUILD_DIR@ and @PROG@.
+# @BUILD_DIR@, @TEMPLATE_DIR@ and @PROG@.
 
 GIT_EXEC_PATH='@BUILD_DIR@'
 if test -n "$NO_SET_GIT_TEMPLATE_DIR"
 then
 	unset GIT_TEMPLATE_DIR
 else
-	GIT_TEMPLATE_DIR='@BUILD_DIR@/templates/blt'
+	GIT_TEMPLATE_DIR='@TEMPLATE_DIR@'
 	export GIT_TEMPLATE_DIR
 fi
-GITPERLLIB='@BUILD_DIR@/perl/build/lib'"${GITPERLLIB:+:$GITPERLLIB}"
-GIT_TEXTDOMAINDIR='@BUILD_DIR@/po/build/locale'
+MERGE_TOOLS_DIR='@MERGE_TOOLS_DIR@'
+GITPERLLIB='@GITPERLLIB@'"${GITPERLLIB:+:$GITPERLLIB}"
+GIT_TEXTDOMAINDIR='@GIT_TEXTDOMAINDIR@'
 PATH='@BUILD_DIR@/bin-wrappers:'"$PATH"
 
-export GIT_EXEC_PATH GITPERLLIB PATH GIT_TEXTDOMAINDIR
+export MERGE_TOOLS_DIR GIT_EXEC_PATH GITPERLLIB PATH GIT_TEXTDOMAINDIR
 
 case "$GIT_DEBUGGER" in
 '')
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index c643a44427..49904ca8a9 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -1100,6 +1100,9 @@ endforeach()
 
 file(STRINGS ${CMAKE_SOURCE_DIR}/bin-wrappers/wrap-for-bin.sh content NEWLINE_CONSUME)
 string(REPLACE "@BUILD_DIR@" "${CMAKE_BINARY_DIR}" content "${content}")
+string(REPLACE "@GIT_TEXTDOMAINDIR@" "${CMAKE_BINARY_DIR}/po/build/locale" content "${content}")
+string(REPLACE "@GITPERLLIB@" "${CMAKE_BINARY_DIR}/perl/build/lib" content "${content}")
+string(REPLACE "@MERGE_TOOLS_DIR@" "${CMAKE_SOURCE_DIR}/mergetools" content "${content}")
 string(REPLACE "@PROG@" "${CMAKE_BINARY_DIR}/git-cvsserver" content "${content}")
 file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/git-cvsserver ${content})
 
@@ -1185,6 +1188,11 @@ string(REPLACE "@GIT_PERF_MAKE_COMMAND@" "" git_build_options "${git_build_optio
 string(REPLACE "@GIT_INTEROP_MAKE_OPTS@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_INDEX_VERSION@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_PERL_FATAL_WARNINGS@" "" git_build_options "${git_build_options}")
+string(REPLACE "@GIT_TEST_TEXTDOMAINDIR@" "'${CMAKE_BINARY_DIR}/po/build/locale'" git_build_options "${git_build_options}")
+string(REPLACE "@GIT_TEST_POPATH@" "'${CMAKE_BINARY_DIR}/po'" git_build_options "${git_build_options}")
+string(REPLACE "@GIT_TEST_TEMPLATE_DIR@" "'${CMAKE_BINARY_DIR}/templates/blt'" git_build_options "${git_build_options}")
+string(REPLACE "@GIT_TEST_GITPERLLIB@" "'${CMAKE_BINARY_DIR}/perl/build/lib'" git_build_options "${git_build_options}")
+string(REPLACE "@GIT_TEST_MERGE_TOOLS_DIR@" "'${RUNTIME_PREFIX}'" git_build_options "${git_build_options}")
 string(REPLACE "@RUNTIME_PREFIX@" "'${RUNTIME_PREFIX}'" git_build_options "${git_build_options}")
 string(REPLACE "@GITWEBDIR@" "'${GITWEBDIR}'" git_build_options "${git_build_options}")
 string(REPLACE "@USE_GETTEXT_SCHEME@" "" git_build_options "${git_build_options}")
diff --git a/t/lib-gettext.sh b/t/lib-gettext.sh
index cc6bb2cdea..7a734c6973 100644
--- a/t/lib-gettext.sh
+++ b/t/lib-gettext.sh
@@ -6,8 +6,8 @@
 
 . ./test-lib.sh
 
-GIT_TEXTDOMAINDIR="$GIT_BUILD_DIR/po/build/locale"
-GIT_PO_PATH="$GIT_BUILD_DIR/po"
+GIT_TEXTDOMAINDIR="$GIT_TEST_TEXTDOMAINDIR"
+GIT_PO_PATH="$GIT_TEST_POPATH"
 export GIT_TEXTDOMAINDIR GIT_PO_PATH
 
 if test -n "$GIT_TEST_INSTALLED"
diff --git a/t/t7609-mergetool--lib.sh b/t/t7609-mergetool--lib.sh
index 330d6d603d..e8e205707e 100755
--- a/t/t7609-mergetool--lib.sh
+++ b/t/t7609-mergetool--lib.sh
@@ -7,7 +7,7 @@ Testing basic merge tools options'
 . ./test-lib.sh
 
 test_expect_success 'mergetool --tool=vimdiff creates the expected layout' '
-	. "$GIT_BUILD_DIR"/mergetools/vimdiff &&
+	. "$GIT_TEST_MERGE_TOOLS_DIR"/vimdiff &&
 	run_unit_tests
 '
 
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 20012f6f47..fe688a3fce 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1419,7 +1419,7 @@ else # normal case, use ../bin-wrappers only unless $with_dashes:
 		PATH="$GIT_BUILD_DIR:$GIT_BUILD_DIR/t/helper:$PATH"
 	fi
 fi
-GIT_TEMPLATE_DIR="$GIT_BUILD_DIR"/templates/blt
+GIT_TEMPLATE_DIR="$GIT_TEST_TEMPLATE_DIR"
 GIT_CONFIG_NOSYSTEM=1
 GIT_ATTR_NOSYSTEM=1
 GIT_CEILING_DIRECTORIES="$TRASH_DIRECTORY/.."
@@ -1485,9 +1485,9 @@ then
 	fi
 fi
 
-GITPERLLIB="$GIT_BUILD_DIR"/perl/build/lib
+GITPERLLIB="$GIT_TEST_GITPERLLIB"
 export GITPERLLIB
-test -d "$GIT_BUILD_DIR"/templates/blt || {
+test -d "$GIT_TEMPLATE_DIR" || {
 	BAIL_OUT "You haven't built things yet, have you?"
 }
 
-- 
cgit v1.3


From 5ee8927824fe5308bc9a1b7c7a1283e79eb135d5 Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Fri, 6 Dec 2024 14:24:57 +0100
Subject: t: allow overriding build dir

Our "test-lib.sh" assumes that our build directory is the parent
directory of "t/". While true when using our Makefile, it's not when
using build systems that support out-of-tree builds.

In commit ee9e66e4e7 (cmake: avoid editing t/test-lib.sh, 2022-10-18),
we have introduce support for overriding the GIT_BUILD_DIR by creating
the file "$GIT_BUILD_DIR/GIT-BUILD-DIR" with its contents pointing to
the location of the build directory. The intent was to stop modifying
"t/test-lib.sh" with the CMake build systems while allowing out-of-tree
builds. But "$GIT_BUILD_DIR" is somewhat misleadingly named, as it in
fact points to the _source_ directory. So while that commit solved part
of the problem for out-of-tree builds, CMake still has to write files
into the source tree.

Solve the second part of the problem, namely not having to write any
data into the source directory at all, by also supporting an environment
variable that allows us to point to a different build directory. This
allows us to perform properly self-contained out-of-tree builds.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index fe688a3fce..62dfcc4aaf 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -35,7 +35,7 @@ else
 	# needing to exist.
 	TEST_DIRECTORY=$(cd "$TEST_DIRECTORY" && pwd) || exit 1
 fi
-GIT_BUILD_DIR="${TEST_DIRECTORY%/t}"
+GIT_BUILD_DIR="${GIT_BUILD_DIR:-${TEST_DIRECTORY%/t}}"
 if test "$TEST_DIRECTORY" = "$GIT_BUILD_DIR"
 then
 	echo "PANIC: Running in a $TEST_DIRECTORY that doesn't end in '/t'?" >&2
@@ -522,6 +522,7 @@ unset VISUAL EMAIL LANGUAGE $("$PERL_PATH" -e '
 		PERF_
 		CURL_VERBOSE
 		TRACE_CURL
+		BUILD_DIR
 	));
 	my @vars = grep(/^GIT_/ && !/^GIT_($ok)/o, @env);
 	print join("\n", @vars);
-- 
cgit v1.3


From cbcc2f79117ded0161b012dc5107f181b5d87b09 Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Fri, 27 Dec 2024 13:10:18 +0100
Subject: GIT-BUILD-OPTIONS: wire up NO_GITWEB option

Building our "gitweb" interface is optional in our Makefile and in Meson
and not wired up at all with CMake, but disabling it causes a couple of
tests in the t950* range that pull in "t/lib-gitweb.sh". This is because
the test library knows to execute gitweb-tests based on whether or not
Perl is available, but we may have Perl available and still end up not
building gitweb e.g. with `make test NO_GITWEB=YesPlease`.

Fix this issue by wiring up a new "NO_GITWEB" build option so that we
can skip these tests in case gitweb is not built.

Note that this new build option requires us to move the configuration of
GIT-BUILD-OPTIONS to a later point in our Meson build instructions. But
as that file is only consumed by our tests at runtime this change does
not cause any issues.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 GIT-BUILD-OPTIONS.in                |  1 +
 Makefile                            |  1 +
 contrib/buildsystems/CMakeLists.txt |  1 +
 meson.build                         | 59 +++++++++++++++++++------------------
 t/lib-gitweb.sh                     |  5 ++++
 t/test-lib.sh                       |  1 +
 6 files changed, 40 insertions(+), 28 deletions(-)

(limited to 't/test-lib.sh')

diff --git a/GIT-BUILD-OPTIONS.in b/GIT-BUILD-OPTIONS.in
index 162cc39190..edff75ae16 100644
--- a/GIT-BUILD-OPTIONS.in
+++ b/GIT-BUILD-OPTIONS.in
@@ -24,6 +24,7 @@ LOCALEDIR=@LOCALEDIR@
 NO_CURL=@NO_CURL@
 NO_EXPAT=@NO_EXPAT@
 NO_GETTEXT=@NO_GETTEXT@
+NO_GITWEB=@NO_GITWEB@
 NO_ICONV=@NO_ICONV@
 NO_PERL=@NO_PERL@
 NO_PERL_CPAN_FALLBACKS=@NO_PERL_CPAN_FALLBACKS@
diff --git a/Makefile b/Makefile
index f80e70702f..97e8385b66 100644
--- a/Makefile
+++ b/Makefile
@@ -3171,6 +3171,7 @@ GIT-BUILD-OPTIONS: FORCE
 		-e "s|@NO_CURL@|\'$(NO_CURL)\'|" \
 		-e "s|@NO_EXPAT@|\'$(NO_EXPAT)\'|" \
 		-e "s|@NO_GETTEXT@|\'$(NO_GETTEXT)\'|" \
+		-e "s|@NO_GITWEB@|\'$(NO_GITWEB)\'|" \
 		-e "s|@NO_ICONV@|\'$(NO_ICONV)\'|" \
 		-e "s|@NO_PERL@|\'$(NO_PERL)\'|" \
 		-e "s|@NO_PERL_CPAN_FALLBACKS@|\'$(NO_PERL_CPAN_FALLBACKS_SQ)\'|" \
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index f45407b060..10dc54fdcb 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -1184,6 +1184,7 @@ string(REPLACE "@LOCALEDIR@" "'${LOCALEDIR}'" git_build_options "${git_build_opt
 string(REPLACE "@NO_CURL@" "${NO_CURL}" git_build_options "${git_build_options}")
 string(REPLACE "@NO_EXPAT@" "${NO_EXPAT}" git_build_options "${git_build_options}")
 string(REPLACE "@NO_GETTEXT@" "${NO_GETTEXT}" git_build_options "${git_build_options}")
+string(REPLACE "@NO_GITWEB@" "1" git_build_options "${git_build_options}")
 string(REPLACE "@NO_ICONV@" "${NO_ICONV}" git_build_options "${git_build_options}")
 string(REPLACE "@NO_PERL@" "${NO_PERL}" git_build_options "${git_build_options}")
 string(REPLACE "@NO_PERL_CPAN_FALLBACKS@" "" git_build_options "${git_build_options}")
diff --git a/meson.build b/meson.build
index a0654a3f24..3e57793862 100644
--- a/meson.build
+++ b/meson.build
@@ -1456,34 +1456,6 @@ else
   build_options_config.set('RUNTIME_PREFIX', 'false')
 endif
 
-foreach key, value : {
-  'DIFF': diff.full_path(),
-  'GIT_TEST_CMP': diff.full_path() + ' -u',
-  'GIT_TEST_GITPERLLIB': meson.project_build_root() / 'perl',
-  'GIT_TEST_MERGE_TOOLS_DIR': meson.project_source_root() / 'mergetools',
-  'GIT_TEST_POPATH': meson.project_source_root() / 'po',
-  'GIT_TEST_TEMPLATE_DIR': meson.project_build_root() / 'templates',
-  'GIT_TEST_TEXTDOMAINDIR': meson.project_build_root() / 'po',
-  'PAGER_ENV': get_option('pager_environment'),
-  'PERL_PATH': perl.found() ? perl.full_path() : '',
-  'PYTHON_PATH': python.found () ? python.full_path() : '',
-  'SHELL_PATH': shell.full_path(),
-  'TAR': tar.full_path(),
-  'TEST_OUTPUT_DIRECTORY': test_output_directory,
-  'TEST_SHELL_PATH': shell.full_path(),
-}
-  if value != '' and cygpath.found()
-    value = run_command(cygpath, value, check: true).stdout().strip()
-  endif
-  build_options_config.set_quoted(key, value)
-endforeach
-
-configure_file(
-  input: 'GIT-BUILD-OPTIONS.in',
-  output: 'GIT-BUILD-OPTIONS',
-  configuration: build_options_config,
-)
-
 git_version_file = custom_target(
   command: [
     shell,
@@ -1893,6 +1865,9 @@ subdir('contrib')
 gitweb_option = get_option('gitweb').disable_auto_if(not perl.found())
 if gitweb_option.enabled()
   subdir('gitweb')
+  build_options_config.set('NO_GITWEB', '')
+else
+  build_options_config.set('NO_GITWEB', '1')
 endif
 
 subdir('templates')
@@ -1909,6 +1884,34 @@ if get_option('docs') != []
   subdir('Documentation')
 endif
 
+foreach key, value : {
+  'DIFF': diff.full_path(),
+  'GIT_TEST_CMP': diff.full_path() + ' -u',
+  'GIT_TEST_GITPERLLIB': meson.project_build_root() / 'perl',
+  'GIT_TEST_MERGE_TOOLS_DIR': meson.project_source_root() / 'mergetools',
+  'GIT_TEST_POPATH': meson.project_source_root() / 'po',
+  'GIT_TEST_TEMPLATE_DIR': meson.project_build_root() / 'templates',
+  'GIT_TEST_TEXTDOMAINDIR': meson.project_build_root() / 'po',
+  'PAGER_ENV': get_option('pager_environment'),
+  'PERL_PATH': perl.found() ? perl.full_path() : '',
+  'PYTHON_PATH': python.found () ? python.full_path() : '',
+  'SHELL_PATH': shell.full_path(),
+  'TAR': tar.full_path(),
+  'TEST_OUTPUT_DIRECTORY': test_output_directory,
+  'TEST_SHELL_PATH': shell.full_path(),
+}
+  if value != '' and cygpath.found()
+    value = run_command(cygpath, value, check: true).stdout().strip()
+  endif
+  build_options_config.set_quoted(key, value)
+endforeach
+
+configure_file(
+  input: 'GIT-BUILD-OPTIONS.in',
+  output: 'GIT-BUILD-OPTIONS',
+  configuration: build_options_config,
+)
+
 summary({
   'curl': curl.found(),
   'expat': expat.found(),
diff --git a/t/lib-gitweb.sh b/t/lib-gitweb.sh
index 7f9808ec20..a6e3dd11b3 100644
--- a/t/lib-gitweb.sh
+++ b/t/lib-gitweb.sh
@@ -105,6 +105,11 @@ if ! test_have_prereq PERL; then
 	test_done
 fi
 
+if ! test_have_prereq GITWEB; then
+	skip_all='skipping gitweb tests, gitweb not available'
+	test_done
+fi
+
 perl -MEncode -e '$e="";decode_utf8($e, Encode::FB_CROAK)' >/dev/null 2>&1 || {
 	skip_all='skipping gitweb tests, perl version is too old'
 	test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 62dfcc4aaf..1a67adb207 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1687,6 +1687,7 @@ esac
 
 ( COLUMNS=1 && test $COLUMNS = 1 ) && test_set_prereq COLUMNS_CAN_BE_1
 test -z "$NO_CURL" && test_set_prereq LIBCURL
+test -z "$NO_GITWEB" && test_set_prereq GITWEB
 test -z "$NO_ICONV" && test_set_prereq ICONV
 test -z "$NO_PERL" && test_set_prereq PERL
 test -z "$NO_PTHREADS" && test_set_prereq PTHREADS
-- 
cgit v1.3


From d601aee6056a0afc6df7f77e15cdc155ff402dee Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Sun, 29 Dec 2024 23:24:01 -0500
Subject: test-lib: use individual lsan dir for --stress runs

When storing output in test-results/, we usually give each numbered run
in a --stress set its own output file. But we don't do that for storing
LSan logs, so something like:

  ./t0003-attributes.sh --stress

will have many scripts simultaneously creating, writing to, and deleting
the test-results/t0003-attributes.leak directory. This can cause logs
from one run to be attributed to another, spurious failures when
creation and deletion race, and so on.

This has always been broken, but nobody noticed because it's rare to do
a --stress run with LSan (since the point is for the code to run quickly
many times in order to hit races). But if you're trying to find a race
in the leak sanitizing code, it makes sense to use these together.

We can fix it by using $TEST_RESULTS_BASE, which already incorporates
the stress job suffix.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 1a67adb207..96f2dfb69d 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -331,7 +331,7 @@ TEST_RESULTS_BASE="$TEST_RESULTS_DIR/$TEST_NAME$TEST_STRESS_JOB_SFX"
 TEST_RESULTS_SAN_FILE_PFX=trace
 TEST_RESULTS_SAN_DIR_SFX=leak
 TEST_RESULTS_SAN_FILE=
-TEST_RESULTS_SAN_DIR="$TEST_RESULTS_DIR/$TEST_NAME.$TEST_RESULTS_SAN_DIR_SFX"
+TEST_RESULTS_SAN_DIR="$TEST_RESULTS_BASE.$TEST_RESULTS_SAN_DIR_SFX"
 TRASH_DIRECTORY="trash directory.$TEST_NAME$TEST_STRESS_JOB_SFX"
 test -n "$root" && TRASH_DIRECTORY="$root/$TRASH_DIRECTORY"
 case "$TRASH_DIRECTORY" in
-- 
cgit v1.3


From 5fa0c4dd296d3731bbbd1977d7bf9c50d8c4b7c1 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 1 Jan 2025 15:14:44 -0500
Subject: test-lib: rely on logs to detect leaks

When we run with sanitizers, we set abort_on_error=1 so that the tests
themselves can detect problems directly (when the buggy program exits
with SIGABRT). This has one blind spot, though: we don't always check
the exit codes for all programs (e.g., helpers like upload-pack invoked
behind the scenes).

For ASan and UBSan this is mostly fine; they exit as soon as they see an
error, so the unexpected abort of the program causes the test to fail
anyway.

But for LSan, the program runs to completion, since we can only check
for leaks at the end. And in that case we could miss leak reports. And
thus we started checking LSan logs in faececa53f (test-lib: have the
"check" mode for SANITIZE=leak consider leak logs, 2022-07-28).
Originally the logs were optional, but logs are generated (and checked)
always as of 8c1d6691bc (test-lib: GIT_TEST_SANITIZE_LEAK_LOG enabled by
default, 2024-07-11). And we even check them for each test snippet, as
of cf1464331b (test-lib: check for leak logs after every test,
2024-09-24).

So now aborting on error is superfluous for LSan! We can get everything
we need by checking the logs. And checking the logs is actually
preferable, since it gives us more control over silencing false
positives (something we do not yet do, but will soon).

So let's tell LSan to just exit normally, even if it finds leaks. We can
do so with exitcode=0, which also suppresses the abort_on_error flag.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 1 +
 1 file changed, 1 insertion(+)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 96f2dfb69d..dd2ba6e6cc 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -80,6 +80,7 @@ prepend_var ASAN_OPTIONS : detect_leaks=0
 export ASAN_OPTIONS
 
 prepend_var LSAN_OPTIONS : $GIT_SAN_OPTIONS
+prepend_var LSAN_OPTIONS : exitcode=0
 prepend_var LSAN_OPTIONS : fast_unwind_on_malloc=0
 export LSAN_OPTIONS
 
-- 
cgit v1.3


From 373a4326961c504ad6365fc1e4a9082e387499c7 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 1 Jan 2025 15:17:21 -0500
Subject: test-lib: simplify leak-log checking

We have a function to count the number of leaks found (actually, it is
the number of processes which produced a log file). Once upon a time we
cared about seeing if this number increased between runs. But we
simplified that away in 95c679ad86 (test-lib: stop showing old leak
logs, 2024-09-24), and now we only care if it returns any results or
not.

In preparation for refactoring it further, let's drop the counting
function entirely, and roll it into the "is it empty" check. The outcome
should be the same, but we'll be free to return a boolean "did we find
anything" without worrying about somebody adding a new call to the
counting function.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index dd2ba6e6cc..23eb26bfbe 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -340,17 +340,6 @@ case "$TRASH_DIRECTORY" in
  *) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$TRASH_DIRECTORY" ;;
 esac
 
-# Utility functions using $TEST_RESULTS_* variables
-nr_san_dir_leaks_ () {
-	# stderr piped to /dev/null because the directory may have
-	# been "rmdir"'d already.
-	find "$TEST_RESULTS_SAN_DIR" \
-		-type f \
-		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
-	xargs grep -lv "Unable to get registers from thread" |
-	wc -l
-}
-
 # If --stress was passed, run this test repeatedly in several parallel loops.
 if test "$GIT_TEST_STRESS_STARTED" = "done"
 then
@@ -1181,8 +1170,14 @@ test_atexit_handler () {
 }
 
 check_test_results_san_file_empty_ () {
-	test -z "$TEST_RESULTS_SAN_FILE" ||
-	test "$(nr_san_dir_leaks_)" = 0
+	test -z "$TEST_RESULTS_SAN_FILE" && return 0
+
+	# stderr piped to /dev/null because the directory may have
+	# been "rmdir"'d already.
+	! find "$TEST_RESULTS_SAN_DIR" \
+		-type f \
+		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
+	xargs grep -qv "Unable to get registers from thread"
 }
 
 check_test_results_san_file_ () {
-- 
cgit v1.3


From 6fb8cb3d685382089a2e34ba35a30e898d63ab26 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 1 Jan 2025 15:18:28 -0500
Subject: test-lib: check leak logs for presence of DEDUP_TOKEN

When we check the leak logs, our original strategy was to check for any
non-empty log file produced by LSan. We later amended that to ignore
noisy lines in 370ef7e40d (test-lib: ignore uninteresting LSan output,
2023-08-28).

This makes it hard to ignore noise which is more than a single line;
we'd have to actually parse the file to determine the meaning of each
line.

But there's an easy line-oriented solution. Because we always pass the
dedup_token_length option, the output will contain a DEDUP_TOKEN line
for each leak that has been found. So if we invert our strategy to stop
ignoring useless lines and only look for useful ones, we can just count
the number of DEDUP_TOKEN lines. If it's non-zero, then we found at
least one leak (it would even give us a count of unique leaks, but we
really only care if it is non-zero).

This should yield the same outcome, but will help us build more false
positive detection on top.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 23eb26bfbe..c9487d0805 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1177,7 +1177,7 @@ check_test_results_san_file_empty_ () {
 	! find "$TEST_RESULTS_SAN_DIR" \
 		-type f \
 		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
-	xargs grep -qv "Unable to get registers from thread"
+	xargs grep -q ^DEDUP_TOKEN
 }
 
 check_test_results_san_file_ () {
-- 
cgit v1.3


From b119a687d411864433aed92017c144d311b53a4c Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Wed, 1 Jan 2025 15:21:24 -0500
Subject: test-lib: ignore leaks in the sanitizer's thread code

Our CI jobs sometimes see false positive leaks like this:

        =================================================================
        ==3904583==ERROR: LeakSanitizer: detected memory leaks

        Direct leak of 32 byte(s) in 1 object(s) allocated from:
            #0 0x7fa790d01986 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
            #1 0x7fa790add769 in __pthread_getattr_np nptl/pthread_getattr_np.c:180
            #2 0x7fa790d117c5 in __sanitizer::GetThreadStackTopAndBottom(bool, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:150
            #3 0x7fa790d11957 in __sanitizer::GetThreadStackAndTls(bool, unsigned long*, unsigned long*, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:598
            #4 0x7fa790d03fe8 in __lsan::ThreadStart(unsigned int, unsigned long long, __sanitizer::ThreadType) ../../../../src/libsanitizer/lsan/lsan_posix.cpp:51
            #5 0x7fa790d013fd in __lsan_thread_start_func ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:440
            #6 0x7fa790adc3eb in start_thread nptl/pthread_create.c:444
            #7 0x7fa790b5ca5b in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

This is not a leak in our code, but appears to be a race between one
thread calling exit() while another one is in LSan's stack setup code.
You can reproduce it easily by running t0003 or t5309 with --stress
(these trigger it because of the threading in git-grep and index-pack
respectively).

This may be a bug in LSan, but regardless of whether it is eventually
fixed, it is useful to work around it so that we stop seeing these false
positives.

We can recognize it by the mention of the sanitizer functions in the
DEDUP_TOKEN line. With this patch, the scripts mentioned above should
run with --stress indefinitely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index c9487d0805..d1f62adbf8 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1177,7 +1177,8 @@ check_test_results_san_file_empty_ () {
 	! find "$TEST_RESULTS_SAN_DIR" \
 		-type f \
 		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
-	xargs grep -q ^DEDUP_TOKEN
+	xargs grep ^DEDUP_TOKEN |
+	grep -qv sanitizer::GetThreadStackTopAndBottom
 }
 
 check_test_results_san_file_ () {
-- 
cgit v1.3


From 8d24d56ce1da13caff82cfa8950413309e08da13 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Tue, 7 Jan 2025 02:05:01 -0500
Subject: test-lib: invert return value of check_test_results_san_file_empty

We have a function to check whether LSan logged any leaks. It returns
success for no leaks, and non-zero otherwise. This is the simplest thing
for its callers, who want to say "if no leaks then return early". But
because it's implemented as a shell pipeline, you end up with the
awkward:

  ! find ... |
  xargs grep leaks |
  grep -v false-positives

where the "!" is actually negating the final grep. Switch the return
value (and name) to return success when there are leaks. This should
make the code a little easier to read, and the negation in the callers
still reads pretty naturally.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib-functions.sh | 2 +-
 t/test-lib.sh           | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 78e054ab50..c25cee0ad8 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -927,7 +927,7 @@ test_expect_success () {
 		test -n "$test_skip_test_preamble" ||
 		say >&3 "expecting success of $TEST_NUMBER.$test_count '$1': $test_body"
 		if test_run_ "$test_body" &&
-		   check_test_results_san_file_empty_
+		   ! check_test_results_san_file_has_entries_
 		then
 			test_ok_ "$1"
 		else
diff --git a/t/test-lib.sh b/t/test-lib.sh
index d1f62adbf8..be3553e40e 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1169,12 +1169,12 @@ test_atexit_handler () {
 	teardown_malloc_check
 }
 
-check_test_results_san_file_empty_ () {
-	test -z "$TEST_RESULTS_SAN_FILE" && return 0
+check_test_results_san_file_has_entries_ () {
+	test -z "$TEST_RESULTS_SAN_FILE" && return 1
 
 	# stderr piped to /dev/null because the directory may have
 	# been "rmdir"'d already.
-	! find "$TEST_RESULTS_SAN_DIR" \
+	find "$TEST_RESULTS_SAN_DIR" \
 		-type f \
 		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
 	xargs grep ^DEDUP_TOKEN |
@@ -1182,7 +1182,7 @@ check_test_results_san_file_empty_ () {
 }
 
 check_test_results_san_file_ () {
-	if check_test_results_san_file_empty_
+	if ! check_test_results_san_file_has_entries_
 	then
 		return
 	fi &&
-- 
cgit v1.3


From b9a9df93a3f5580c7f7b8cc099aad1c204ced8a4 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Tue, 7 Jan 2025 02:07:52 -0500
Subject: test-lib: simplify lsan results check

We want to know if there are any leaks logged by LSan in the results
directory, so we run "find" on the containing directory and pipe it to
xargs. We can accomplish the same thing by just globbing in the shell
and passing the result to grep, which has a few advantages:

  - it's one fewer process to run

  - we can glob on the TEST_RESULTS_SAN_FILE pattern, which is what we
    checked at the beginning of the function, and is the same glob used
    to show the logs in check_test_results_san_file_

  - this correctly handles the case where TEST_OUTPUT_DIRECTORY has a
    space in it. For example doing:

       mkdir "/tmp/foo bar"
       TEST_OUTPUT_DIRECTORY="/tmp/foo bar" make SANITIZE=leak test

    would yield a lot of:

      grep: /tmp/foo: No such file or directory
      grep: bar/test-results/t0006-date.leak/trace.test-tool.582311: No such file or directory

    when there are leaks. We could do the same thing with "xargs
    --null", but that isn't portable.

We are now subject to command-line length limits, but that is also true
of the globbing cat used to show the logs themselves. This hasn't been a
problem in practice.

We do need to use "grep -s" for the case that the glob does not expand
(i.e., there are not any log files at all). This option is in POSIX, and
has been used in t7407 for several years without anybody complaining.
This also also naturally handles the case where the surrounding
directory has already been removed (in which case there are likewise no
files!), dropping the need to comment about it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index be3553e40e..898c2267b8 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1172,12 +1172,7 @@ test_atexit_handler () {
 check_test_results_san_file_has_entries_ () {
 	test -z "$TEST_RESULTS_SAN_FILE" && return 1
 
-	# stderr piped to /dev/null because the directory may have
-	# been "rmdir"'d already.
-	find "$TEST_RESULTS_SAN_DIR" \
-		-type f \
-		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
-	xargs grep ^DEDUP_TOKEN |
+	grep -s ^DEDUP_TOKEN "$TEST_RESULTS_SAN_FILE".* |
 	grep -qv sanitizer::GetThreadStackTopAndBottom
 }
 
-- 
cgit v1.3


From 164a2516eb622fdf032ce526ec97e79a53bf2893 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Tue, 7 Jan 2025 02:08:31 -0500
Subject: test-lib: add a few comments to LSan log checking

Commit b119a687d4 (test-lib: ignore leaks in the sanitizer's thread
code, 2025-01-01) added code to suppress a false positive in the leak
checker. But if you're just reading the code, the obscure grep call is a
bit of a head-scratcher. Let's add a brief comment explaining what's
going on (and anybody digging further can find this commit or that one
for all the details).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/test-lib.sh | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 't/test-lib.sh')

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 898c2267b8..9f27a49995 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1172,6 +1172,11 @@ test_atexit_handler () {
 check_test_results_san_file_has_entries_ () {
 	test -z "$TEST_RESULTS_SAN_FILE" && return 1
 
+	# Lines marked with DEDUP_TOKEN show unique leaks. We only care that we
+	# found at least one.
+	#
+	# But also suppress any false positives caused by bugs or races in the
+	# sanitizer itself.
 	grep -s ^DEDUP_TOKEN "$TEST_RESULTS_SAN_FILE".* |
 	grep -qv sanitizer::GetThreadStackTopAndBottom
 }
-- 
cgit v1.3


From c5bc9a7f94a41c3e719afebf4a6c3e04cba82e4d Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Wed, 22 Jan 2025 12:31:29 +0100
Subject: Makefile: wire up build option for deprecated features

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 enable the breaking change at compile-time.
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. This does not yet wire up
the build flag for existing deprecations.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 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(+)

(limited to 't/test-lib.sh')

diff --git a/GIT-BUILD-OPTIONS.in b/GIT-BUILD-OPTIONS.in
index f651116102..f1d0ecf123 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 06f01149ec..dc3c980aa7 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 $@+ $@; fi
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index 49904ca8a9..63d0088928 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -1198,6 +1198,7 @@ string(REPLACE "@GITWEBDIR@" "'${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 0dccebcdf1..316cd93264 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 32a72139ba..800e518d95 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 62dfcc4aaf..6e423f655d 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).
-- 
cgit v1.3