build: support selecting enabled utils in Meson

Add a new Meson array option, utils, to allow building only selected applets while keeping the default as all.

Gate source inclusion, dependencies, symlink/manpage/script install steps, and test registration by enabled util set, and make applet dispatch in src/main.c compile-time conditional via generated config defines.

Document selective build usage in README.

README.md

@@ -13,6 +13,7 @@ It bundles a growing set of FreeBSD-derived userland tools into a single `vx` bi
 - `grep`, `egrep`, `fgrep`, `rgrep`
 - `find`
 - `xargs`
+- `lspci`, `setpci`
 
 ## Build
 
@@ -24,6 +25,14 @@ meson compile -C builddir
 meson test -C builddir
 ```
 
+To build only selected utilities:
+
+```text
+meson setup builddir -Dutils=grep,find,xargs
+```
+
+The default is `-Dutils=all`.
+
 ## Run
 
 You can invoke applets either through the multicall binary:

meson.build

@@ -6,6 +6,61 @@ project('vx', 'c',
   ],
 )
 
+all_utils = [
+  'patch',
+  'diff',
+  'cmp',
+  'diff3',
+  'sdiff',
+  'which',
+  'gzip',
+  'grep',
+  'find',
+  'xargs',
+  'lspci',
+  'setpci',
+]
+
+requested_utils = get_option('utils')
+if requested_utils.length() == 0
+  error('utils option cannot be empty; specify one or more utilities or use "all"')
+endif
+
+enabled_utils = []
+if requested_utils.contains('all')
+  enabled_utils = all_utils
+else
+  enabled_utils = requested_utils
+endif
+
+enable_patch = enabled_utils.contains('patch')
+enable_diff = enabled_utils.contains('diff')
+enable_cmp = enabled_utils.contains('cmp')
+enable_diff3 = enabled_utils.contains('diff3')
+enable_sdiff = enabled_utils.contains('sdiff')
+enable_which = enabled_utils.contains('which')
+enable_gzip = enabled_utils.contains('gzip')
+enable_grep = enabled_utils.contains('grep')
+enable_find = enabled_utils.contains('find')
+enable_xargs = enabled_utils.contains('xargs')
+enable_lspci = enabled_utils.contains('lspci')
+enable_setpci = enabled_utils.contains('setpci')
+
+vx_cfg = configuration_data()
+vx_cfg.set10('VX_ENABLE_PATCH', enable_patch)
+vx_cfg.set10('VX_ENABLE_DIFF', enable_diff)
+vx_cfg.set10('VX_ENABLE_CMP', enable_cmp)
+vx_cfg.set10('VX_ENABLE_DIFF3', enable_diff3)
+vx_cfg.set10('VX_ENABLE_SDIFF', enable_sdiff)
+vx_cfg.set10('VX_ENABLE_WHICH', enable_which)
+vx_cfg.set10('VX_ENABLE_GZIP', enable_gzip)
+vx_cfg.set10('VX_ENABLE_GREP', enable_grep)
+vx_cfg.set10('VX_ENABLE_FIND', enable_find)
+vx_cfg.set10('VX_ENABLE_XARGS', enable_xargs)
+vx_cfg.set10('VX_ENABLE_LSPCI', enable_lspci)
+vx_cfg.set10('VX_ENABLE_SETPCI', enable_setpci)
+configure_file(output : 'vx-config.h', configuration : vx_cfg)
+
 # --- Portability shim for building BSD userland on Linux ---
 compat_inc = include_directories('src/compat-headers')
 
@@ -77,14 +132,6 @@ grep_src = files(
 
 grep_inc = include_directories('src/grep')
 
-# --- yacc generator for find's getdate.y ---
-yacc = find_program('yacc', 'bison')
-getdate_gen = custom_target('getdate',
-  input : 'src/find/getdate.y',
-  output : 'getdate.c',
-  command : [yacc, '-o', '@OUTPUT@', '@INPUT@'],
-)
-
 find_src = files(
   'src/find/find.c',
   'src/find/function.c',
@@ -104,9 +151,15 @@ xargs_src = files(
 
 xargs_inc = include_directories('src/xargs')
 
-pci_src = files(
+pci_common_src = files(
   'src/pci/pci.c',
+)
+
+lspci_src = files(
   'src/pci/lspci.c',
+)
+
+setpci_src = files(
   'src/pci/setpci.c',
 )
 
@@ -117,49 +170,160 @@ gzip_defines = [
   '-DNO_ZSTD_SUPPORT',
 ]
 
+vx_sources = files('src/main.c')
+vx_sources += compat_src
+vx_include_dirs = [compat_inc]
+vx_c_args = compat_args
+
 cc = meson.get_compiler('c')
 libm = cc.find_library('m', required : false)
-libz = dependency('zlib')
+vx_dependencies = [libm]
-liblzma = dependency('liblzma')
+
-libacl = cc.find_library('acl', required : true)
+if enable_patch
+  vx_sources += patch_src
+endif
+
+if enable_diff
+  vx_sources += diff_src
+endif
+
+if enable_cmp
+  vx_sources += cmp_src
+endif
+
+if enable_diff3
+  vx_sources += diff3_src
+endif
+
+if enable_sdiff
+  vx_sources += sdiff_src
+endif
+
+if enable_which
+  vx_sources += which_src
+endif
+
+if enable_gzip
+  vx_sources += gzip_src
+  vx_include_dirs += [gzip_inc]
+  vx_c_args += gzip_defines
+  vx_dependencies += [dependency('zlib'), dependency('liblzma')]
+endif
+
+if enable_grep
+  vx_sources += grep_src
+  vx_include_dirs += [grep_inc]
+endif
+
+if enable_find
+  # --- yacc generator for find's getdate.y ---
+  yacc = find_program('yacc', 'bison')
+  getdate_gen = custom_target('getdate',
+    input : 'src/find/getdate.y',
+    output : 'getdate.c',
+    command : [yacc, '-o', '@OUTPUT@', '@INPUT@'],
+  )
+
+  vx_sources += find_src
+  vx_sources += [getdate_gen]
+  vx_include_dirs += [find_inc]
+  vx_dependencies += [cc.find_library('acl', required : true)]
+endif
+
+if enable_xargs
+  vx_sources += xargs_src
+  vx_include_dirs += [xargs_inc]
+endif
+
+if enable_lspci or enable_setpci
+  vx_sources += pci_common_src
+  vx_include_dirs += [pci_inc]
+endif
+
+if enable_lspci
+  vx_sources += lspci_src
+endif
+
+if enable_setpci
+  vx_sources += setpci_src
+endif
 
 vx = executable('vx',
-  'src/main.c',
+  vx_sources,
-  patch_src,
+  include_directories : vx_include_dirs,
-  diff_src,
+  c_args : vx_c_args,
-  cmp_src,
+  dependencies : vx_dependencies,
-  diff3_src,
-  sdiff_src,
-  which_src,
-  gzip_src,
-  grep_src,
-  find_src,
-  getdate_gen,
-  xargs_src,
-  pci_src,
-  compat_src,
-  include_directories : [compat_inc, gzip_inc, grep_inc, find_inc, xargs_inc, pci_inc],
-  c_args : compat_args + gzip_defines,
-  dependencies : [libm, libz, liblzma, libacl],
   install : true,
 )
 
-# Create symlinks for all applets pointing to the vx binary
+# Create symlinks for selected applets pointing to the vx binary.
 bindir = get_option('bindir')
-foreach name : ['patch', 'diff', 'cmp', 'diff3', 'sdiff', 'which', 'gzip', 'gunzip', 'zcat', 'uncompress', 'grep', 'egrep', 'fgrep', 'rgrep', 'find', 'xargs', 'lspci', 'setpci']
+install_applets = []
+if enable_patch
+  install_applets += ['patch']
+endif
+if enable_diff
+  install_applets += ['diff']
+endif
+if enable_cmp
+  install_applets += ['cmp']
+endif
+if enable_diff3
+  install_applets += ['diff3']
+endif
+if enable_sdiff
+  install_applets += ['sdiff']
+endif
+if enable_which
+  install_applets += ['which']
+endif
+if enable_gzip
+  install_applets += ['gzip', 'gunzip', 'zcat', 'uncompress']
+endif
+if enable_grep
+  install_applets += ['grep', 'egrep', 'fgrep', 'rgrep']
+endif
+if enable_find
+  install_applets += ['find']
+endif
+if enable_xargs
+  install_applets += ['xargs']
+endif
+if enable_lspci
+  install_applets += ['lspci']
+endif
+if enable_setpci
+  install_applets += ['setpci']
+endif
+
+foreach name : install_applets
   meson.add_install_script('sh', '-c',
     'ln -sf vx "$MESON_INSTALL_DESTDIR_PREFIX/' + bindir + '/' + name + '"',
   )
 endforeach
 
 # --- Manpages ---
-install_man(
+manpages = []
-  'src/patch/patch.1',
+if enable_patch
-  'src/diff/diff.1',
+  manpages += ['src/patch/patch.1']
-  'src/cmp/cmp.1',
+endif
-  'src/diff3/diff3.1',
+if enable_diff
-  'src/sdiff/sdiff.1',
+  manpages += ['src/diff/diff.1']
-  'src/which/which.1',
+endif
+if enable_cmp
+  manpages += ['src/cmp/cmp.1']
+endif
+if enable_diff3
+  manpages += ['src/diff3/diff3.1']
+endif
+if enable_sdiff
+  manpages += ['src/sdiff/sdiff.1']
+endif
+if enable_which
+  manpages += ['src/which/which.1']
+endif
+if enable_gzip
+  manpages += [
     'src/gzip/gzip.1',
     'src/gzip/gzexe.1',
     'src/gzip/zdiff.1',
@@ -167,33 +331,86 @@ install_man(
     'src/gzip/zmore.1',
     'src/gzip/znew.1',
     'src/gzip/zgrep.1',
-  'src/grep/grep.1',
+  ]
-  'src/find/find.1',
+endif
-  'src/xargs/xargs.1',
+if enable_grep
-  'src/pci/lspci.8',
+  manpages += ['src/grep/grep.1']
-  'src/pci/setpci.8',
+endif
-)
+if enable_find
+  manpages += ['src/find/find.1']
+endif
+if enable_xargs
+  manpages += ['src/xargs/xargs.1']
+endif
+if enable_lspci
+  manpages += ['src/pci/lspci.8']
+endif
+if enable_setpci
+  manpages += ['src/pci/setpci.8']
+endif
 
-# --- Gzip shell script utilities ---
+install_man(manpages)
-foreach s : ['zdiff', 'zforce', 'zmore', 'znew', 'gzexe', 'zgrep', 'zless']
+
+if enable_gzip
+  # --- Gzip shell script utilities ---
+  foreach s : ['zdiff', 'zforce', 'zmore', 'znew', 'gzexe', 'zgrep', 'zless']
     install_data('src/gzip/' + s,
       install_dir : get_option('bindir'),
       install_mode : 'rwxr-xr-x',
     )
-endforeach
+  endforeach
 
-# Install symlinks for script aliases
+  # Install symlinks for script aliases
-foreach pair : [['zcmp', 'zdiff'], ['zegrep', 'zgrep'], ['zfgrep', 'zgrep']]
+  foreach pair : [['zcmp', 'zdiff'], ['zegrep', 'zgrep'], ['zfgrep', 'zgrep']]
     meson.add_install_script('sh', '-c',
       'ln -sf ' + pair[1] + ' "$MESON_INSTALL_DESTDIR_PREFIX/' + bindir + '/' + pair[0] + '"',
     )
-endforeach
+  endforeach
+endif
 
 # --- Tests ---
 test_env = environment()
 test_env.set('VX', vx.full_path())
 
-foreach t : ['test_patch', 'test_diff', 'test_cmp', 'test_diff3', 'test_sdiff', 'test_which', 'test_gzip', 'test_grep', 'test_find', 'test_xargs', 'test_lspci', 'test_setpci']
+test_targets = []
+if enable_patch
+  test_targets += ['test_patch']
+endif
+if enable_diff
+  test_targets += ['test_diff']
+endif
+if enable_cmp
+  test_targets += ['test_cmp']
+endif
+if enable_diff3
+  test_targets += ['test_diff3']
+endif
+if enable_sdiff
+  test_targets += ['test_sdiff']
+endif
+if enable_which
+  test_targets += ['test_which']
+endif
+if enable_gzip
+  test_targets += ['test_gzip']
+endif
+if enable_grep
+  test_targets += ['test_grep']
+endif
+if enable_find
+  test_targets += ['test_find']
+endif
+if enable_xargs
+  test_targets += ['test_xargs']
+endif
+if enable_lspci
+  test_targets += ['test_lspci']
+endif
+if enable_setpci
+  test_targets += ['test_setpci']
+endif
+
+foreach t : test_targets
   test(t, find_program('tests/' + t + '.sh'),
     env : test_env,
     depends : vx,

meson_options.txt

@@ -0,0 +1,20 @@
+option('utils',
+  type : 'array',
+  value : ['all'],
+  choices : [
+    'all',
+    'patch',
+    'diff',
+    'cmp',
+    'diff3',
+    'sdiff',
+    'which',
+    'gzip',
+    'grep',
+    'find',
+    'xargs',
+    'lspci',
+    'setpci',
+  ],
+  description : 'Utilities to include in vx (default: all)'
+)

src/main.c

@@ -1,20 +1,46 @@
+#include "vx-config.h"
+
 #include <libgen.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 
+#if VX_ENABLE_PATCH
 int patch_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_DIFF
 int diff_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_CMP
 int cmp_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_DIFF3
 int diff3_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_SDIFF
 int sdiff_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_WHICH
 int which_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_GZIP
 int gzip_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_GREP
 int grep_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_FIND
 int find_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_XARGS
 int xargs_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_LSPCI
 int lspci_main(int argc, char *argv[]);
+#endif
+#if VX_ENABLE_SETPCI
 int setpci_main(int argc, char *argv[]);
+#endif
 
 struct applet {
 	const char *name;
@@ -22,25 +48,49 @@ struct applet {
 };
 
 static const struct applet applets[] = {
+#if VX_ENABLE_PATCH
 	{ "patch", patch_main },
+#endif
+#if VX_ENABLE_DIFF
 	{ "diff",  diff_main },
+#endif
+#if VX_ENABLE_CMP
 	{ "cmp",   cmp_main },
+#endif
+#if VX_ENABLE_DIFF3
 	{ "diff3", diff3_main },
+#endif
+#if VX_ENABLE_SDIFF
 	{ "sdiff", sdiff_main },
+#endif
+#if VX_ENABLE_WHICH
 	{ "which", which_main },
+#endif
+#if VX_ENABLE_GZIP
 	{ "gzip", gzip_main },
 	{ "gunzip", gzip_main },
 	{ "zcat", gzip_main },
 	{ "gzcat", gzip_main },
 	{ "uncompress", gzip_main },
+#endif
+#if VX_ENABLE_GREP
 	{ "grep", grep_main },
 	{ "egrep", grep_main },
 	{ "fgrep", grep_main },
 	{ "rgrep", grep_main },
+#endif
+#if VX_ENABLE_FIND
 	{ "find", find_main },
+#endif
+#if VX_ENABLE_XARGS
 	{ "xargs", xargs_main },
+#endif
+#if VX_ENABLE_LSPCI
 	{ "lspci", lspci_main },
+#endif
+#if VX_ENABLE_SETPCI
 	{ "setpci", setpci_main },
+#endif
 };
 
 static const size_t n_applets = sizeof(applets) / sizeof(applets[0]);