build: fix FreeBSD build when sysinfo compat library installed

Commit 50dec7c566 ("config.mak.uname: add sysinfo() configuration for
cygwin", 2025-04-17) and later commit 187ce0222f ("configure.ac: upgrade
to a compilation check for sysinfo", 2025-05-19) added a 'sysinfo()'
check to the autoconf build.

The FreeBSD system has an optional sysinfo compatibility library, used
to assist in porting software, which causes the build to fail when it
is installed. The reason for the failure is the lack of '-lsysinfo'
during the linking step.

Several solutions were considered:

  - add a 'linking' check to configure.ac in order to determine the
    need to link a separate library (-lsysinfo). (This would require
    a similar change to meson.build).

  - change the order of the preprocessor conditionals in the total_ram()
    function in 'builtin/gc.c', so that the *BSD sysctl() function
    (in the HAVE_BSD_SYSCTL block) takes priority over the sysinfo()
    function (in the HAVE_SYSINFO block).

  - suppress the setting of HAVE_SYSINFO when HAVE_BSD_SYSCTL has been
    defined (in both configure.ac and meson.build).

The first solution above, while simple, adds unnecessary code (the
sysinfo compat function is likely implemented using sysctl() anyway)
when git is happy to use sysctl() on *BSD systems.

The second solution would only be required by the autoconf and meson
build systems, the Makefile already sets the build variables to the
required values (since they are not 'auto-detected').

Here we opt for the final solution above, since it only requires that
we prioritise the 'auto-detected' build variables in the autoconf and
meson builds.

In order to fix the FreeBSD build, move the sysinfo() check after the
determination of the HAVE_BSD_SYSCTL build variable, suppressing the
setting of HAVE_SYSINFO if HAVE_BSD_SYSCTL is defined. Apply this logic
to both the configure.ac and meson.build file.

[Thanks go to Renato Botelho <garga@FreeBSD.org> for testing this patch
on FreeBSD.]

Tested-by: Renato Botelho <garga@FreeBSD.org>
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/configure.ac b/configure.ac
index f6caab919a3e0e351954815c758ea6ddf0e6c117..bf710ac91a450d6ae9c695ca505039cdee676a5e 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1067,32 +1067,6 @@ AC_CHECK_LIB([iconv], [locale_charset],
                      [CHARSET_LIB=-lcharset])])
 GIT_CONF_SUBST([CHARSET_LIB])
 
-#
-# Define HAVE_SYSINFO=YesPlease if sysinfo is available.
-#
-AC_DEFUN([HAVE_SYSINFO_SRC], [
-AC_LANG_PROGRAM([[
-#include <stdint.h>
-#include <sys/sysinfo.h>
-]], [[
-struct sysinfo si;
-uint64_t t = 0;
-if (!sysinfo(&si)) {
-       t = si.totalram;
-       if (si.mem_unit > 1)
-               t *= (uint64_t)si.mem_unit;
-}
-return t;
-]])])
-
-AC_MSG_CHECKING([for sysinfo])
-AC_COMPILE_IFELSE([HAVE_SYSINFO_SRC],
-       [AC_MSG_RESULT([yes])
-       HAVE_SYSINFO=YesPlease],
-       [AC_MSG_RESULT([no])
-       HAVE_SYSINFO=])
-GIT_CONF_SUBST([HAVE_SYSINFO])
-
 #
 # Define HAVE_CLOCK_GETTIME=YesPlease if clock_gettime is available.
 GIT_CHECK_FUNC(clock_gettime,
@@ -1221,6 +1195,41 @@ AC_COMPILE_IFELSE([BSD_SYSCTL_SRC],
        HAVE_BSD_SYSCTL=])
 GIT_CONF_SUBST([HAVE_BSD_SYSCTL])
 
+#
+# Define HAVE_SYSINFO=YesPlease if sysinfo is available.
+#
+
+HAVE_SYSINFO=
+# on a *BSD system, sysctl() takes precedence over the
+# sysinfo() compatibility library (if installed).
+
+if test -z "$HAVE_BSD_SYSCTL"; then
+
+  AC_DEFUN([HAVE_SYSINFO_SRC], [
+  AC_LANG_PROGRAM([[
+  #include <stdint.h>
+  #include <sys/sysinfo.h>
+  ]], [[
+  struct sysinfo si;
+  uint64_t t = 0;
+  if (!sysinfo(&si)) {
+       t = si.totalram;
+       if (si.mem_unit > 1)
+               t *= (uint64_t)si.mem_unit;
+  }
+  return t;
+  ]])])
+
+  AC_MSG_CHECKING([for sysinfo])
+  AC_COMPILE_IFELSE([HAVE_SYSINFO_SRC],
+       [AC_MSG_RESULT([yes])
+       HAVE_SYSINFO=YesPlease],
+       [AC_MSG_RESULT([no])
+       HAVE_SYSINFO=])
+  GIT_CONF_SUBST([HAVE_SYSINFO])
+
+fi
+
 ## Other checks.
 # Define NO_SYMLINK_HEAD if you never want .git/HEAD to be a symbolic link.
 # Enable it on Windows.  By default, symrefs are still used.

diff --git a/meson.build b/meson.build
index 596f5ac7110ebf608ced79dc335226d10a09b4a8..70d2f86f4b0fa93e8618fecbcf448ab563e7d7af 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -1331,10 +1331,6 @@ if host_machine.system() != 'windows'
   endif
 endif
 
-if compiler.has_member('struct sysinfo', 'totalram', prefix: '#include <sys/sysinfo.h>')
-  libgit_c_args += '-DHAVE_SYSINFO'
-endif
-
 if compiler.has_member('struct stat', 'st_mtimespec.tv_nsec', prefix: '#include <sys/stat.h>')
   libgit_c_args += '-DUSE_ST_TIMESPEC'
 elif not compiler.has_member('struct stat', 'st_mtim.tv_nsec', prefix: '#include <sys/stat.h>')
@@ -1449,6 +1445,12 @@ if compiler.has_header('sys/sysctl.h')
   endif
 endif
 
+if not has_bsd_sysctl
+  if compiler.has_member('struct sysinfo', 'totalram', prefix: '#include <sys/sysinfo.h>')
+    libgit_c_args += '-DHAVE_SYSINFO'
+  endif
+endif
+
 if not meson.is_cross_build() and compiler.run('''
   #include <stdio.h>