mintro: Add exclude_{files, dirs} to install_subdir install_plan

These are necessary for projects outside Meson itself that want to
extend the 'meson install' functionality as meson-python does to
assemble Python package wheels from Meson projects.

Fixes #11426.

mesonbuild/mintro.py

@@ -146,11 +146,19 @@ def list_install_plan(installdata: backends.InstallData) -> T.Dict[str, T.Dict[s
             if key == 'headers':  # in the headers, install_path_name is the directory
                 install_path_name = os.path.join(install_path_name, os.path.basename(data.path))
 
-            plan[data_type] = plan.get(data_type, {})
-            plan[data_type][data.path] = {
+            entry = {
                 'destination': install_path_name,
                 'tag': data.tag or None,
             }
+
+            if key == 'install_subdirs':
+                exclude_files, exclude_dirs = data.exclude or ([], [])
+                entry['exclude_dirs'] = list(exclude_dirs)
+                entry['exclude_files'] = list(exclude_files)
+
+            plan[data_type] = plan.get(data_type, {})
+            plan[data_type][data.path] = entry
+
     return plan
 
 def get_target_dir(coredata: cdata.CoreData, subdir: str) -> str:

test cases/unit/98 install all targets/excludes/excluded.txt

@@ -0,0 +1 @@
+Excluded

test cases/unit/98 install all targets/excludes/excluded/placeholder.txt

@@ -0,0 +1 @@
+Placeholder

test cases/unit/98 install all targets/excludes/installed.txt

@@ -0,0 +1 @@
+Installed

test cases/unit/98 install all targets/meson.build

@@ -94,6 +94,12 @@ install_subdir('custom_files',
   install_dir: get_option('datadir'),
   install_tag: 'custom',
 )
+install_subdir('excludes',
+  install_dir: get_option('datadir'),
+  install_tag: 'custom',
+  exclude_directories: 'excluded',
+  exclude_files: 'excluded.txt',
+)
 
 # First is custom, 2nd is devel, 3rd has no tag
 custom_target('ct3',

unittests/allplatformstests.py

@@ -4235,6 +4235,8 @@ class AllPlatformTests(BasePlatformTests):
             Path(installpath, 'usr/share/out3-custom.txt'),
             Path(installpath, 'usr/share/custom_files'),
             Path(installpath, 'usr/share/custom_files/data.txt'),
+            Path(installpath, 'usr/share/excludes'),
+            Path(installpath, 'usr/share/excludes/installed.txt'),
             Path(installpath, 'usr/lib'),
             Path(installpath, 'usr/lib/libbothcustom.a'),
             Path(installpath, 'usr/' + shared_lib_name('bothcustom')),
@@ -4442,7 +4444,15 @@ class AllPlatformTests(BasePlatformTests):
             'install_subdirs': {
                 f'{testdir}/custom_files': {
                     'destination': '{datadir}/custom_files',
-                    'tag': 'custom'
+                    'tag': 'custom',
+                    'exclude_dirs': [],
+                    'exclude_files': [],
+                },
+                f'{testdir}/excludes': {
+                    'destination': '{datadir}/excludes',
+                    'tag': 'custom',
+                    'exclude_dirs': ['excluded'],
+                    'exclude_files': ['excluded.txt'],
                 }
             }
         }