Ramsay JonesThis series contains some miscellaneous changes to the make, meson and autoconf build systems. These are only the patches I have managed to write a commit message for; I have some others with no commit message, some need more testing and others are yet to be written. (So, there will be a 'part #2' series later... :) ).
(I have notes from a couple of months ago - as an example, I have a note that the meson build incorrectly sets ETC_GITATTRIBUTES and ETC_GITCONFIG to e.g. '/etc/gitattributes' rather than 'etc/gitattributes').
This series is based on the master branch at commit 683c54c999 ("Git 2.49", 2025-03-14).
As a simple means for comparing the build products, we can compare the symbols exported by git. So, starting at current master:
$ git checkout master Switched to branch 'master' Your branch is up-to-date with 'origin/master'. $ git describe v2.49.0 $
$ make >out 2>&1 $
$ meson setup build/ The Meson build system ... Found ninja-1.11.1 at /usr/bin/ninja $
$ cd build $ meson compile INFO: autodetecting backend as ninja INFO: calculating backend command to run: /usr/bin/ninja [661/661] Copying file contrib/completion/git-completion.zsh $ cd .. $
$ rm *.syms $ ./syms.pl git >git.syms 2>/dev/null $ ./syms.pl build/git >mgit.syms 2>/dev/null $
$ diff git.syms mgit.syms 88a89 > U -- arc4random_buf@GLIBC_2.36 98a100,101 > U -- atoi@GLIBC_2.2.5 > U -- atol@GLIBC_2.2.5 195a199 > U -- bsearch@GLIBC_2.2.5 586,587d589 < U -- dcgettext@GLIBC_2.2.5 < U -- dcngettext@GLIBC_2.2.5 746,747c748,749 < B -- __environ@GLIBC_2.2.5 < V -- environ@GLIBC_2.2.5 --- > U -- __environ@GLIBC_2.2.5 > U -- environ@GLIBC_2.2.5 909c911 < U -- __fprintf_chk@GLIBC_2.3.4 --- > U -- fprintf@GLIBC_2.2.5 914d915 < U -- __fread_chk@GLIBC_2.7 1007c1008 < U -- getc@GLIBC_2.2.5 --- > U -- getchar@GLIBC_2.2.5 1018a1020 > U -- getc_unlocked@GLIBC_2.2.5 1107a1110 > U -- gettext@GLIBC_2.2.5 1253d1255 < T -- gitstrlcpy 1355a1358 > U -- htons@GLIBC_2.2.5 1666d1668 < U -- __memcpy_chk@GLIBC_2.3.4 1673d1674 < U -- __memmove_chk@GLIBC_2.3.4 1684d1684 < U -- __memset_chk@GLIBC_2.3.4 1737a1738 > U -- ngettext@GLIBC_2.2.5 1759a1761 > U -- ntohs@GLIBC_2.2.5 1819d1820 < U -- __open64_2@GLIBC_2.7 1988a1990,2007 > U -- pcre2_code_free_8 > U -- pcre2_compile_8 > U -- pcre2_compile_context_create_8 > U -- pcre2_compile_context_free_8 > U -- pcre2_config_8 > U -- pcre2_general_context_create_8 > U -- pcre2_general_context_free_8 > U -- pcre2_get_error_message_8 > U -- pcre2_get_ovector_pointer_8 > U -- pcre2_jit_compile_8 > U -- pcre2_jit_match_8 > U -- pcre2_maketables_8 > U -- pcre2_maketables_free_8 > U -- pcre2_match_8 > U -- pcre2_match_data_create_from_pattern_8 > U -- pcre2_match_data_free_8 > U -- pcre2_pattern_info_8 > U -- pcre2_set_character_tables_8 2045c2064 < U -- __printf_chk@GLIBC_2.3.4 --- > U -- printf@GLIBC_2.2.5 2080a2100 > U -- pthread_equal@GLIBC_2.2.5 2767c2787 < U -- __snprintf_chk@GLIBC_2.3.4 --- > U -- snprintf@GLIBC_2.2.5 2925a2946 > U -- strlcpy@GLIBC_2.38 3185d3205 < U -- __uflow@GLIBC_2.2.5 3289,3290c3309,3311 < U -- __vfprintf_chk@GLIBC_2.3.4 < U -- __vsnprintf_chk@GLIBC_2.3.4 --- > U -- vfprintf@GLIBC_2.2.5 > U -- vprintf@GLIBC_2.2.5 > U -- vsnprintf@GLIBC_2.2.5 $
Looking at the above, you can see that quite a few differences relate to symbols which differ due to the level of optimization during compilation. This reflects, among other things, the different 'default' settings between the Makefile and the meson build; e.g. prefix=$HOME vs. /usr/local, initial CFLAGS='-g -O2 -Wall' vs. '-g -O0 -Wall'. Also, note that the make build does not include the (optional) pcre2 library, even if it is installed on the system.
[On cygwin the diff is slightly different, but also contains more symbols, such as all symbols relating to the compat regex routines, clock_gettime, getdelim, sysinfo and so on ... ;) ]
If we change the meson setup, thus:
$ meson setup --optimization=2 -Dprefix=$HOME -Dpcre2=disabled build/
After we re-build and repeat the above symbol generation, we find:
$ diff git.syms mgit.syms 88a89 > U -- arc4random_buf@GLIBC_2.36 746,747c747,748 < B -- __environ@GLIBC_2.2.5 < V -- environ@GLIBC_2.2.5 --- > U -- __environ@GLIBC_2.2.5 > U -- environ@GLIBC_2.2.5 1253d1253 < T -- gitstrlcpy 2925a2926 > U -- strlcpy@GLIBC_2.38 $
After applying these patches and adding settings to the config.mak file:
$ vim config.mak # add NO_STRLCPY and CSPRNG_METHOD $ $ cat config.mak DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS='--timer' PYTHON_PATH=/usr/bin/python3 GIT_TEST_HTTPD=false export GIT_TEST_HTTPD #DEVELOPER=1 SPARSE_FLAGS += -D__STDC_NO_VLA__ NO_STRLCPY= CSPRNG_METHOD=arc4random $
[Note that I commented out DEVELOPER=1. I'm not entirely sure why I did that. :) Maybe it was one less variable? ]
$ make >out 2>&1 $
$ meson setup --optimization=2 -Dprefix=$HOME -Dpcre2=disabled build/
The Meson build system
...
User defined options
optimization: 2
prefix : /home/ramsay
pcre2 : disabled
Found ninja-1.11.1 at /usr/bin/ninja
$ $ cd build $ meson compile INFO: autodetecting backend as ninja INFO: calculating backend command to run: /usr/bin/ninja [661/661] Copying file contrib/completion/git-prompt.sh $ cd .. $
$ rm *.syms $ ./syms.pl git >git.syms 2>/dev/null $ ./syms.pl build/git >mgit.syms 2>/dev/null $
$ diff git.syms mgit.syms 747,748c747,748 < B -- __environ@GLIBC_2.2.5 < V -- environ@GLIBC_2.2.5 --- > U -- __environ@GLIBC_2.2.5 > U -- environ@GLIBC_2.2.5 $ On cygwin, this diff is now empty. ;)
The above diff seems to imply a difference in the linking of main() and the C library startup routines (or something similar). However, I happened to notice that the meson build included '-fPIC' in the build flags, so I thought it was worth a punt:
$ make CFLAGS='-g -O2 -Wall -fPIC' >out 2>&1
[with the advent of ASLR, I thought -fPIC/-fPIE was the default anyway!]
$ diff git.syms mgit.syms 2809,2811c2809,2811 < U -- stderr@GLIBC_2.2.5 < U -- stdin@GLIBC_2.2.5 < U -- stdout@GLIBC_2.2.5 --- > B -- stderr@GLIBC_2.2.5 > B -- stdin@GLIBC_2.2.5 > B -- stdout@GLIBC_2.2.5 $
Hmm, so one step forward, one step back! (or is it 2 steps forward, 3 steps back? ;) ). So, something for another day.
Note that both test suite runs ('make test' and 'meson test') pass all tests (excluding the http, cvs, svn, and p4 tests) on Linux. (I am still waiting for the v2.49.0 test run to finish on cygwin! :( ).
Also, patches #5 and #12 only add/modify a comment, so they could be dropped, if people feel that they are not appropriate.
[Just in case you want to reproduce the above, I have appended the syms.pl script below.]
ATB, Ramsay Jones
Ramsay Jones (12): meson.build: remove -DCURL_DISABLE_TYPECHECK Makefile: only set some BASIC_CFLAGS when RUNTIME_PREFIX is set meson.build: only set build variables for non-default values Makefile: remove NEEDS_LIBRT build variable config.mak.uname: add a note about NO_STRLCPY for Linux config.mak.uname: only set NO_REGEX on cygwin for v1.7 config.mak.uname: add HAVE_GETDELIM to the cygwin section config.mak.uname: add clock_gettime() to the cygwin build builtin/gc.c: correct RAM calculation when using sysinfo config.mak.uname: add sysinfo() configuration for cygwin config.mak.uname; add arc4random to the cygwin build config.mak.uname: add a note about CSPRNG_METHOD for Linux
Makefile | 45 +++++++++++++++++++++++---------------------- builtin/gc.c | 9 +++++++-- config.mak.uname | 16 ++++++++++++---- configure.ac | 8 ++++++++ meson.build | 14 ++++++++++---- 5 files changed, 60 insertions(+), 32 deletions(-)
--
2.49.0
----------------- >8 ------------------ [syms.pl]
#!/usr/bin/perl -w
open(I, "-|", qw(nm -g), $ARGV[0]) or die;
while (<I>) {
unless (/^[0-9a-f ]+ ([A-Z]) (\S*)$/) {
print STDERR "? $_";
next;
}
next if ($2 =~ /^\.refptr\./);
print "$1 -- $2\n";
}
close I;
