[mm-common] skeletonmm: Some fixes in the Meson build system

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 17617ce926cf35230ec9fbe04e53b85afbd26988
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Wed Apr 15 15:49:29 2020 +0200

    skeletonmm: Some fixes in the Meson build system
    
    * meson.build: Remove dist-cmd.py from the skeletonmm tarball.
    * skeletonmm/doc/reference/meson.build:
    * skeletonmm/skeleton/skeletonmm/meson.build: Don't use dist-cmd.py.
    * skeletonmm/meson.build: Don't use dist-cmd.py. Add a better error message
    if mm-common-get is required but not found. If not maintainer-mode, check
    that generate-binding.py exists.
    * skeletonmm/meson_options.txt: Default value of warnings is 'min'.
    Add dist-warnings.
    * skeletonmm/tools/dist-cmd.py: Removed file. It's not necessary in
    add_dist_script() when the first parameter is python3.path().

 meson.build                                |  1 -
 skeletonmm/doc/reference/meson.build       |  3 +--
 skeletonmm/meson.build                     | 33 ++++++++++++++++++++++++------
 skeletonmm/meson_options.txt               |  6 ++++--
 skeletonmm/skeleton/skeletonmm/meson.build |  3 +--
 skeletonmm/tools/dist-cmd.py               | 12 -----------
 6 files changed, 33 insertions(+), 25 deletions(-)
---
diff --git a/meson.build b/meson.build
index 92c639a..df2a3c3 100644
--- a/meson.build
+++ b/meson.build
@@ -237,7 +237,6 @@ skeletonmm_basefiles = [
   'tests/meson.build',
   'tests/test1/main.cc',
   'tests/test2/main.cc',
-  'tools/dist-cmd.py',
   'tools/generate_defs_and_docs.sh',
   'tools/extra_defs_gen/generate_defs_skeleton.cc',
   'tools/extra_defs_gen/meson.build',
diff --git a/skeletonmm/doc/reference/meson.build b/skeletonmm/doc/reference/meson.build
index 1ff7194..e1989aa 100644
--- a/skeletonmm/doc/reference/meson.build
+++ b/skeletonmm/doc/reference/meson.build
@@ -2,7 +2,7 @@
 
 # Input: built_files_root, project_source_root, skeletonmm_pcname, perl,
 #        hg_ccg_basenames, extra_h_files, built_h_file_targets, install_datadir,
-#        dist_cmd, python3
+#        python3
 # Output: install_docdir, install_devhelpdir
 
 tag_file_modules = [
@@ -137,7 +137,6 @@ if not meson.is_subproject()
   # Distribute built files and files copied by mm-common-prepare.
   # (add_dist_script() is not allowed in a subproject)
   meson.add_dist_script(
-    python3.path(), dist_cmd,
     python3.path(), doc_reference, 'dist_doc',
     doctool_dir,
     doctool_dist_dir,
diff --git a/skeletonmm/meson.build b/skeletonmm/meson.build
index 0c885c6..717c49e 100644
--- a/skeletonmm/meson.build
+++ b/skeletonmm/meson.build
@@ -52,11 +52,21 @@ sys.exit(os.path.isdir("@0@") or os.path.isfile("@0@"))
 '''.format(project_source_root / '.git')
 is_git_build = run_command(python3, '-c', cmd_py).returncode() != 0
 
+# Are we testing a dist tarball while it's being built?
+is_dist_check = project_source_root.contains('dist-unpack') and \
+                project_build_root.contains('dist-build')
+
 # Options.
 maintainer_mode_opt = get_option('maintainer-mode')
 maintainer_mode = maintainer_mode_opt == 'true' or \
                  (maintainer_mode_opt == 'if-git-build' and is_git_build)
-warning_level = get_option('warnings')
+if is_dist_check
+  message('Looks like a tarball is being tested. ' + \
+          'Option "dist-warnings" is used instead of "warnings".')
+  warning_level = get_option('dist-warnings')
+else
+  warning_level = get_option('warnings')
+endif
 build_deprecated_api = get_option('build-deprecated-api')
 build_documentation_opt = get_option('build-documentation')
 build_documentation = build_documentation_opt == 'true' or \
@@ -87,7 +97,10 @@ gnome = import('gnome')
 
 # Some dependencies are required only in maintainer mode and/or if
 # reference documentation shall be built.
-mm_common_get = find_program('mm-common-get', required: maintainer_mode)
+mm_common_get = find_program('mm-common-get', required: false)
+if maintainer_mode and not mm_common_get.found()
+  error('mm-common-get not found. mm-common >= 1.0.0 is required.')
+endif
 m4 = find_program('m4', required: maintainer_mode) # Used by gmmproc (in glibmm)
 perl = find_program('perl', required: maintainer_mode or build_documentation)
 doxygen = find_program('doxygen', required: build_documentation)
@@ -97,18 +110,28 @@ xsltproc = find_program('xsltproc', required: build_documentation)
 # Where to find gmmproc and generate_wrap_init.pl.
 gmmproc_dir = glibmm_dep.get_pkgconfig_variable('gmmprocdir')
 
+# Script files copied to 'untracked' by mm-common-get.
 script_dir = project_source_root / 'untracked' / 'build_scripts'
 generate_binding = script_dir / 'generate-binding.py'
 doc_reference = script_dir / 'doc-reference.py'
 dist_changelog = script_dir / 'dist-changelog.py'
 dist_build_scripts = script_dir / 'dist-build-scripts.py'
 check_dllexport_usage = script_dir / 'check-dllexport-usage.py'
-dist_cmd = project_source_root / 'tools' / 'dist-cmd.py' # Must be committed to git.
 
-if maintainer_mode and mm_common_get.found()
+if maintainer_mode
   # Copy files to untracked/build_scripts and untracked/doc.
   run_command(mm_common_get, '--force', script_dir,
     project_source_root / 'untracked' / 'doc')
+else
+  cmd_py = '''
+import os
+import sys
+sys.exit(os.path.isfile("@0@"))
+'''.format(generate_binding)
+  file_exists = run_command(python3, '-c', cmd_py).returncode() != 0
+  if not file_exists
+    error('Missing files in untracked/. You must enable maintainer-mode.')
+  endif
 endif
 
 cpp_compiler = meson.get_compiler('cpp')
@@ -141,14 +164,12 @@ if not meson.is_subproject()
   # Add a ChangeLog file to the distribution directory.
   # (add_dist_script() is not allowed in a subproject)
   meson.add_dist_script(
-    python3.path(), dist_cmd,
     python3.path(), dist_changelog,
     project_source_root,
   )
   # Add build scripts to the distribution directory, and delete .gitignore
   # files and an empty $MESON_DIST_ROOT/build/ directory.
   meson.add_dist_script(
-    python3.path(), dist_cmd,
     python3.path(), dist_build_scripts,
     project_source_root,
     'untracked' / 'build_scripts',
diff --git a/skeletonmm/meson_options.txt b/skeletonmm/meson_options.txt
index 6611d15..5cf429d 100644
--- a/skeletonmm/meson_options.txt
+++ b/skeletonmm/meson_options.txt
@@ -1,7 +1,9 @@
 option('maintainer-mode', type: 'combo', choices: ['false', 'if-git-build', 'true'],
   value: 'if-git-build', description: 'Generate source code from .hg and .ccg files')
-option('warnings', type: 'combo', choices: ['no', 'min', 'max', 'fatal'], value: 'fatal',
-  description: 'Compiler warning level')
+option('warnings', type: 'combo', choices: ['no', 'min', 'max', 'fatal'],
+  value: 'min', description: 'Compiler warning level')
+option('dist-warnings', type: 'combo', choices: ['no', 'min', 'max', 'fatal'],
+  value: 'fatal', description: 'Compiler warning level when a tarball is created')
 option('build-deprecated-api', type: 'boolean', value: true,
   description: 'Build deprecated API and include it in the library')
 option('build-documentation', type: 'combo', choices: ['false', 'if-maintainer-mode', 'true'],
diff --git a/skeletonmm/skeleton/skeletonmm/meson.build b/skeletonmm/skeleton/skeletonmm/meson.build
index 89e9373..db6327a 100644
--- a/skeletonmm/skeleton/skeletonmm/meson.build
+++ b/skeletonmm/skeleton/skeletonmm/meson.build
@@ -2,7 +2,7 @@
 
 # Input: skeletonmm_build_dep, skeletonmm_pcname, maintainer_mode, project_source_root,
 #        generate_binding, m4_files, skeletonmm_libversion, install_includedir,
-#        dist_cmd, python3
+#        python3
 # Output: hg_ccg_basenames, extra_h_files, built_h_file_targets, built_files_root,
 #         skeletonmm_dep
 
@@ -158,7 +158,6 @@ if not meson.is_subproject()
   # Distribute built files.
   # (add_dist_script() is not allowed in a subproject)
   meson.add_dist_script(
-    python3.path(), dist_cmd,
     python3.path(), generate_binding, 'dist_built_files',
     built_h_cc_dir,
     untracked_skeletonmm,