[PATCH v4 3/5] meson: correct path to system config/attribute files

From: Ramsay Jones <ramsay@ramsayjones.plus.com>
Date: May 19, 2025, 16:25 UTC
Message-ID: <20250519162523.1001478-4-ramsay@ramsayjones.plus.com>
In-Reply-To: <20250519162523.1001478-1-ramsay@ramsayjones.plus.com>

The path to the system-wide config and attributes files are not being set correctly in the meson build. Unless explicitly overridden on the command line during setup, the 'gitconfig' and 'gitattributes' options are defaulting to absolute paths in the '/etc' system directory. This is only appropriate if the <prefix> is set specifically to '/usr'.

The directory in which these files are placed is generally referred to as the 'system configuration directory' or 'sysconfdir' for short. When the prefix is '/usr' then the sysconfdir is usually set to '/etc', but any other value for prefix results in the relative directory value 'etc' instead. (eg if prefix is '/usr/local', then the 'etc' relative value results in a system configuration directory of '/usr/local/etc'). When setting the 'sysconfdir' builtin option value, the meson system uses exactly this algorithm, so we can use get_option('sysconfdir') directly when setting the (non-overridden) build variables.

In order to allow for overriding from the command line, remove the default values specified for the 'gitconfig' and 'gitattributes' options in the 'meson_options.txt' file. This allows the user to specify any pathname for those options, while being able to test for the unset (empty) value. An absolute pathname will be used unchanged and a relative pathname will be appended to '<prefix>/'. These values are then used to set the 'ETC_GITCONFIG' and 'ETC_GITATTRIBUTES' build variables which are, in turn, passed to the compiler as '-D' arguments.

When the 'gitconfig' or 'gitattributes' options are not used, then use the built-in 'sysconfdir' and set the ETC_GITCONFIG build variable to the string "<sysconfdir>/gitconfig". Similarly, set ETC_ATTRIBUTES to "<sysconfdir>/gitattributes".

Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
---
 meson.build       | 16 ++++++++++++++--
 meson_options.txt |  8 ++++----
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/meson.build b/meson.build
index 48f31157a0..8e8f228a37 100644
--- a/meson.build
+++ b/meson.build
@@ -757,8 +757,6 @@ endif
 libgit_c_args = [
   '-DBINDIR="' + get_option('bindir') + '"',
   '-DDEFAULT_GIT_TEMPLATE_DIR="' + get_option('datadir') / 'git-core/templates' + '"',
-  '-DETC_GITATTRIBUTES="' + get_option('gitattributes') + '"',
-  '-DETC_GITCONFIG="' + get_option('gitconfig') + '"',
   '-DFALLBACK_RUNTIME_PREFIX="' + get_option('prefix') + '"',
   '-DGIT_HOST_CPU="' + host_machine.cpu_family() + '"',
   '-DGIT_HTML_PATH="' + get_option('datadir') / 'doc/git-doc"',
@@ -769,6 +767,20 @@ libgit_c_args = [
   '-DSHELL_PATH="' + fs.as_posix(target_shell.full_path()) + '"',
 ]
 
+system_attributes = get_option('gitattributes')
+if system_attributes != ''
+  libgit_c_args += '-DETC_GITATTRIBUTES="' + system_attributes + '"'
+else
+  libgit_c_args += '-DETC_GITATTRIBUTES="' + get_option('sysconfdir') / 'gitattributes"'
+endif
+
+system_config = get_option('gitconfig')
+if system_config != ''
+  libgit_c_args += '-DETC_GITCONFIG="' + system_config + '"'
+else
+  libgit_c_args += '-DETC_GITCONFIG="' + get_option('sysconfdir') / 'gitconfig"'
+endif
+
 editor_opt = get_option('default_editor')
 if editor_opt != '' and editor_opt != 'vi'
   libgit_c_args += '-DDEFAULT_EDITOR="' + editor_opt + '"'
diff --git a/meson_options.txt b/meson_options.txt
index 8547c0eb47..5afbf8ec00 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -3,10 +3,10 @@ option('default_pager', type: 'string', value: 'less',
   description: 'Fall-back pager.')
 option('default_editor', type: 'string', value: 'vi',
   description: 'Fall-back editor.')
-option('gitconfig', type: 'string', value: '/etc/gitconfig',
-  description: 'Path to the global git configuration file.')
-option('gitattributes', type: 'string', value: '/etc/gitattributes',
-  description: 'Path to the global git attributes file.')
+option('gitconfig', type: 'string',
+  description: 'Path to the global git configuration file. (default: etc/gitconfig)')
+option('gitattributes', type: 'string',
+  description: 'Path to the global git attributes file. (default: etc/gitattributes)')
 option('pager_environment', type: 'string', value: 'LESS=FRX LV=-c',
   description: 'Environment used when spawning the pager')
 option('perl_cpan_fallback', type: 'boolean', value: true,

-- 
2.49.0