add install_emptydir function

This replaces the absolute hack of using

```
install_subdir('nonexisting', install_dir: 'share')
```

which requires you to make sure you don't accidentally or deliberately
have a completely different directory with the same name in your source
tree that is full of files you don't want installed. It also avoids
splitting the name in two and listing them in the wrong order.

You can also set the install mode of each directory component by listing
them one at a time in order, and in fact create nested structures at
all.

Fixes #1604
Properly fixes #2904

1 files changed, 14 insertions, 0 deletions

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 311732e..ef2210e 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -187,6 +187,16 @@ class Man(HoldableObject):
         return self.sources
 
 
+class EmptyDir(HoldableObject):
+
+    def __init__(self, path: str, install_mode: 'FileMode', subproject: str,
+                 install_tag: T.Optional[str] = None):
+        self.path = path
+        self.install_mode = install_mode
+        self.subproject = subproject
+        self.install_tag = install_tag
+
+
 class InstallDir(HoldableObject):
 
     def __init__(self, src_subdir: str, inst_subdir: str, install_dir: str,
@@ -239,6 +249,7 @@ class Build:
         self.benchmarks: T.List['Test'] = []
         self.headers: T.List[Headers] = []
         self.man: T.List[Man] = []
+        self.emptydir: T.List[EmptyDir] = []
         self.data: T.List[Data] = []
         self.static_linker: PerMachine[StaticLinker] = PerMachine(None, None)
         self.subprojects = {}
@@ -316,6 +327,9 @@ class Build:
     def get_data(self) -> T.List['Data']:
         return self.data
 
+    def get_emptydir(self) -> T.List['EmptyDir']:
+        return self.emptydir
+
     def get_install_subdirs(self) -> T.List['InstallDir']:
         return self.install_dirs