meson.build: Simplify if-file-exists test

kjellahl · kjellahl · commit b9dcf7e9bbf5 · 2023-03-20T14:43:12.000+01:00
and use meson.project_[build,source]_root(), new in meson 0.56.0.
diff --git a/meson.build b/meson.build
@@ -37,10 +37,9 @@ macos_darwin_versions = [
   '@0@.@1@'.format(libtool_soversion[0] + 1, libtool_soversion[1])
 ]
 
-# Use these instead of meson.source_root() and meson.build_root() in subdirectories.
-# source_root() and build_root() are not useful, if this is a subproject.
-project_source_root = meson.current_source_dir()
-project_build_root = meson.current_build_dir()
+# Source and build root directories of the current (sub)project.
+project_source_root = meson.project_source_root()
+project_build_root = meson.project_build_root()
 
 cpp_compiler = meson.get_compiler('cpp')
 is_msvc = cpp_compiler.get_id() == 'msvc'
@@ -237,17 +236,9 @@ if maintainer_mode
     project_source_root / 'untracked' / 'docs',
     check: true,
   )
-else
-  cmd_py = '''
-import os
-import sys
-sys.exit(os.path.isfile("@0@"))
-'''.format(doc_reference_py)
-  file_exists = run_command(python3, '-c', cmd_py, check: false).returncode() != 0
-  if not file_exists
-    warning('Missing files in untracked/. ' + \
-      'Enable maintainer-mode if you want to build documentation or create a dist tarball.')
-  endif
+elif not import('fs').is_file(doc_reference_py)
+  warning('Missing files in untracked/.\n  ' + \
+  'Enable maintainer-mode if you want to build documentation or create a dist tarball.')
 endif
 
 # Check if perl is required and available.
