feat: set up macros for buildrequires generation

data/macros.meson

@@ -45,3 +45,8 @@
         --num-processes %{_smp_build_ncpus} \
         --print-errorlogs \
         %{nil}}
+
+%meson_buildrequires \
+     %{shrink: mesongenbuildreq %{__meson} \
+    %{nil}}
+

data/mesongenbuildreq.py

@@ -0,0 +1,16 @@
+import subprocess
+import json
+import sys
+deps_json = json.loads(subprocess.run(['sys.argv[0]', "introspect", "--dependencies", "meson.build"], capture_output=True).stdout)
+deps = dict(zip([x['name'] for x in deps_json],[x['version'] for x in deps_json]))
+deps.pop('', None)
+for lib, versions in deps.items() :
+     # Prepare version constraint
+     version_str = ' ' + ' '.join(versions) if versions else ''
+     line = []
+     for prefix in ["cmake", "pkgconfig", "qmake"] :
+         buildreq = (f"{prefix}({lib}){version_str}")
+         if buildreq.split('=')[-1] == '' and '=' in buildreq :
+             buildreq = buildreq.split('=')[0]
+         line.append(buildreq)
+     print(f"BuildRequires: ({' or '.join(line)})")