meson: add support for dtrace/systemtap

Still at least one FIXME. And untested so far. It builds.

gio/meson.build

@@ -681,8 +681,17 @@ install_data([
 ],
 install_dir: join_paths(get_option('datadir'), 'bash-completion/completions'))
 
+if enable_dtrace
+  gio_dtrace_obj = dtrace_obj_gen.process('gio_probes.d')
+  gio_dtrace_hdr = dtrace_hdr_gen.process('gio_probes.d')
+else
+  gio_dtrace_obj = []
+  gio_dtrace_hdr = []
+endif
+
 libgio = shared_library('gio-2.0',
   gioenumtypes_h, gioenumtypes_c, gnetworking_h, gio_sources,
+  gio_dtrace_hdr, gio_dtrace_obj,
   version : library_version,
   soversion : soversion,
   install : true,
@@ -802,6 +811,14 @@ if host_system != 'windows'
     dependencies : [libintl, libgio_dep, libgobject_dep, libgmodule_dep, libglib_dep])
 endif
 
+if enable_systemtap
+  gio_stp = configure_file(input : 'gio.stp.in',
+    output : '@0@.stp'.format(libgio.full_path().split('/').get(-1)),
+    configuration : stp_cdata,
+    install_dir : tapset_install_dir,
+    install : true)
+endif
+
 if host_system != 'windows'
   subdir('tests')
 endif

glib/meson.build

@@ -199,7 +199,16 @@ else
   platform_deps = []
 endif
 
+if enable_dtrace
+  glib_dtrace_obj = dtrace_obj_gen.process('glib_probes.d')
+  glib_dtrace_hdr = dtrace_hdr_gen.process('glib_probes.d')
+else
+  glib_dtrace_obj = []
+  glib_dtrace_hdr = []
+endif
+
 libglib = shared_library('glib-2.0',
+  glib_dtrace_obj, glib_dtrace_hdr,
   sources : [deprecated_sources, glib_sources, thread_src, plat_src],
   version : library_version,
   soversion : soversion,
@@ -264,6 +273,14 @@ configure_file(
   install_dir: join_paths(get_option('datadir'), 'gdb/auto-load' + glib_libdir)
 )
 
+if enable_systemtap
+  glib_stp = configure_file(input : 'glib.stp.in',
+    output : '@0@.stp'.format(libglib.full_path().split('/').get(-1)),
+    configuration : stp_cdata,
+    install_dir : tapset_install_dir,
+    install : true)
+endif
+
 # gtester doesn't work on native windows
 if cc.get_id() != 'msvc'
   subdir('tests')

gobject/meson.build

@@ -45,7 +45,16 @@ gobject_c_sources = [
   'gvaluetypes.c',
 ]
 
+if enable_dtrace
+  gobject_dtrace_obj = dtrace_obj_gen.process('gobject_probes.d')
+  gobject_dtrace_hdr = dtrace_hdr_gen.process('gobject_probes.d')
+else
+  gobject_dtrace_obj = []
+  gobject_dtrace_hdr = []
+endif
+
 libgobject = shared_library('gobject-2.0',
+  gobject_dtrace_obj, gobject_dtrace_hdr,
   sources : [gobject_c_sources],
   version : library_version,
   soversion : soversion,
@@ -94,4 +103,12 @@ configure_file(
   install_dir: join_paths(get_option('datadir'), 'gdb/auto-load/' + glib_libdir)
 )
 
+if enable_systemtap
+  gobject_stp = configure_file(input : 'gobject.stp.in',
+    output : '@0@.stp'.format(libgobject.full_path().split('/').get(-1)),
+    configuration : stp_cdata,
+    install_dir : tapset_install_dir,
+    install : true)
+endif
+
 subdir('tests')

meson.build

@@ -1340,6 +1340,50 @@ glib_conf.set('GIO_MODULE_DIR', '${libdir}/gio/modules')
 # @G_MODULE_LIBS@ @SELINUX_LIBS@ @COCOA_LIBS@ @CARBON_LIBS@ @G_LIBS_EXTRA@
 # @PCRE_REQUIRES@ @GLIB_EXTRA_CFLAGS@ @G_THREAD_CFLAGS@
 
+# Tracing: dtrace
+want_dtrace = get_option('enable-dtrace')
+enable_dtrace = false
+
+# Since dtrace support is opt-in we just error out if it was requested but
+# is not available. We don't bother with autodetection yet.
+if want_dtrace
+  if glib_have_carbon
+    error('GLib dtrace support not yet compatible with macOS dtrace')
+  endif
+  dtrace = find_program('dtrace', required : true) # error out if not found
+  if not cc.has_header('sys/sdt.h')
+    error('dtrace support needs sys/sdt.h header')
+  endif
+  # FIXME: autotools build also passes -fPIC -DPIC but is it needed in this case?
+  dtrace_obj_gen = generator(dtrace,
+    output : '@BASENAME@.o',
+    arguments : ['-G', '-s', '@INPUT@', '-o', '@OUTPUT@'])
+  # FIXME: $(SED) -e "s,define STAP_HAS_SEMAPHORES 1,undef STAP_HAS_SEMAPHORES,"
+  #               -e "s,define _SDT_HAS_SEMAPHORES 1,undef _SDT_HAS_SEMAPHORES,"
+  dtrace_hdr_gen = generator(dtrace,
+    output : '@BASENAME@.h',
+    arguments : ['-h', '-s', '@INPUT@', '-o', '@OUTPUT@'])
+  glib_conf.set('HAVE_DTRACE', 1)
+  enable_dtrace = true
+endif
+
+# systemtap
+want_systemtap = get_option('enable-systemtap')
+enable_systemtap = false
+
+if want_systemtap and enable_dtrace
+  tapset_install_dir = get_option('tapset-install-dir')
+  if tapset_install_dir == ''
+    tapset_install_dir = join_paths(get_option('datadir'), 'systemtap/tapset')
+  endif
+  stp_cdata = configuration_data()
+  stp_cdata.set('ABS_GLIB_RUNTIME_LIBDIR', glib_libdir)
+  stp_cdata.set('LT_CURRENT', minor_version.to_int() * 100)
+  stp_cdata.set('LT_REVISION', micro_version.to_int())
+  enable_systemtap = true
+endif
+
+
 subdir('glib')
 subdir('gobject')
 subdir('gthread')

meson_options.txt

@@ -1,3 +1,9 @@
 option('with-docs', type : 'boolean', value : false)
 option('with-man', type : 'boolean', value : true)
 option('enable-libmount', type : 'combo', choices : ['auto', 'yes', 'no'], value : 'yes')
+option('enable-dtrace', type : 'boolean', value : false,
+  description : 'include tracing support for dtrace')
+option('enable-systemtap', type : 'boolean', value : false,
+  description : 'include tracing support for systemtap')
+option('tapset-install-dir', type : 'string', value : '',
+  description : 'path where systemtap tapsets are installed')