build: use regexp in gtkdoc --ignore-decorators option

gtkdoc-scan supports regular expressions in the --ignore-decorators
command-line option. Since it is easier to use a regexp than grepping
macros from a source file, revert the ugly solution from commit
2d941dc95a ('build: fix errors when building with gtk-doc 1.32').

(cherry picked from commit 11cf082a62)
(cherry picked from commit a369e61d2a)

docs/libnm/Makefile.am

@@ -18,10 +18,8 @@ DOC_SOURCE_DIR= \
 	$(top_srcdir)/libnm \
 	$(top_builddir)/libnm
 
-decorators := $(shell $(top_srcdir)/tools/decorators.sh $(top_srcdir)/libnm-core/nm-version.h)
-
 # Extra options to supply to gtkdoc-scan.
-SCAN_OPTIONS=--rebuild-types --rebuild-sections --ignore-decorators "$(decorators)"
+SCAN_OPTIONS=--rebuild-types --rebuild-sections --ignore-decorators="NM_AVAILABLE_IN_\d_\d\d?|NM_DEPRECATED_IN_\d_\d\d?"
 
 # Extra options to supply to gtkdoc-mkdb.
 MKDB_OPTIONS=--sgml-mode --output-format=xml

docs/libnm/meson.build

@@ -32,9 +32,6 @@ configure_file(
   configuration: version_conf,
 )
 
-result = run_command(join_paths(meson.source_root(), 'tools', 'decorators.sh'),
-                     join_paths(meson.source_root(), 'libnm-core', 'nm-version.h'))
-
 gnome.gtkdoc(
   doc_module,
   main_xml: doc_module + '-docs.xml',
@@ -46,7 +43,7 @@ gnome.gtkdoc(
   scan_args: [
     '--rebuild-types',
     '--rebuild-sections',
-    '--ignore-decorators=' + result.stdout().strip(),
+    '--ignore-decorators=NM_AVAILABLE_IN_\d_\d\d?|NM_DEPRECATED_IN_\d_\d\d?',
     '--ignore-headers=' + ' '.join(private_headers),
   ],
   scanobjs_args: '--type-init-func="g_type_init();"',

tools/decorators.sh

@@ -1,7 +0,0 @@
-#!/bin/sh
-
-# Extract NM_DEPRECATED_IN_* and NM_AVAILABLE_IN_* macros from a
-# header file and output them in a way suitable to be passed to
-# 'gtkdoc-scan --ignore-decorators'
-
-grep -o "NM_DEPRECATED_IN_[0-9]_[0-9]\+$\|NM_AVAILABLE_IN_[0-9]_[0-9]\+$" "$1" | sed ':a;N;$!ba;s/\n/|/g'