Add Mercurial dist support.

docs/markdown/Release-notes-for-0.42.0.md

@@ -7,4 +7,7 @@ short-description: Release notes for 0.42 (preliminary)
 
 # New features
 
-Add features here as code is merged to master.
+## Distribution tarballs from Mercurial repositories
+
+Creating distribution tarballs can now be made out of projects based on
+Mercurial. As before, this remains possible only with the Ninja backend.

mesonbuild/scripts/dist.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 
+import lzma
 import os
 import shutil
 import subprocess
@@ -71,7 +72,8 @@ def process_submodules(dirname):
             continue
         del_gitfiles(os.path.join(dirname, v))
 
-def create_dist(dist_name, src_root, bld_root, dist_sub):
+
+def create_dist_git(dist_name, src_root, bld_root, dist_sub):
     distdir = os.path.join(dist_sub, dist_name)
     if os.path.exists(distdir):
         shutil.rmtree(distdir)
@@ -89,6 +91,22 @@ def create_dist(dist_name, src_root, bld_root, dist_sub):
     shutil.rmtree(distdir)
     return (xzname, )
 
+
+def create_dist_hg(dist_name, src_root, bld_root, dist_sub):
+    os.makedirs(dist_sub, exist_ok=True)
+
+    tarname = os.path.join(dist_sub, dist_name + '.tar')
+    xzname = tarname + '.xz'
+    subprocess.check_call(['hg', 'archive', '-R', src_root, '-S', '-t', 'tar', tarname])
+    with lzma.open(xzname, 'wb') as xf, open(tarname, 'rb') as tf:
+        shutil.copyfileobj(tf, xf)
+    os.unlink(tarname)
+    # Create only .tar.xz for now.
+    # zipname = os.path.join(dist_sub, dist_name + '.zip')
+    # subprocess.check_call(['hg', 'archive', '-R', src_root, '-S', '-t', 'zip', zipname])
+    return (xzname, )
+
+
 def check_dist(packagename, meson_command):
     print('Testing distribution package %s.' % packagename)
     unpackdir = tempfile.mkdtemp()
@@ -133,10 +151,13 @@ def run(args):
 
     dist_name = build.project_name + '-' + build.project_version
 
-    if not os.path.isdir(os.path.join(src_root, '.git')):
-        print('Dist currently only works with Git repos.')
+    if os.path.isdir(os.path.join(src_root, '.git')):
+        names = create_dist_git(dist_name, src_root, bld_root, dist_sub)
+    elif os.path.isdir(os.path.join(src_root, '.hg')):
+        names = create_dist_hg(dist_name, src_root, bld_root, dist_sub)
+    else:
+        print('Dist currently only works with Git or Mercurial repos.')
         return 1
-    names = create_dist(dist_name, src_root, bld_root, dist_sub)
     if names is None:
         return 1
     error_count = 0