Add a built-in hash function

hash constant is widely used in file verification, so
I suggest adding a built-in `hash()` function as
a basic function. For its usage example:

```
hash_str = hash('foobar', 'sha1') # return a sha1 constant
# some process
```

Author: rruuaanng

data/syntax-highlighting/vim/syntax/meson.vim

@@ -109,6 +109,7 @@ syn keyword mesonBuiltin
   \ jar
   \ join_paths
   \ library
+  \ hash
   \ message
   \ project
   \ range

docs/yaml/functions/hash.yaml

@@ -0,0 +1,38 @@
+name: hash
+returns: str
+description: |
+  Run the specified algorithm to calculate the hash constant
+  of a given string.
+
+example: |
+  After being called, it will return the hash constant calculated
+  using the specified algorithm.
+
+  ```meson
+      message(hash('foobar', 'md5'))    # 3858f62230ac3c915f300c664312c63f
+      message(hash('foobar', 'sha1'))   # 8843d7f92416211de9ebb963ff4ce28125932878
+      message(hash('foobar', 'sha256')) # c3ab8ff13720e8ad9047dd39466b3c8974e592c2f
+                                          a383d4a3960714caef0c4f2
+      ...
+  ```
+
+posargs:
+  string:
+    type: str
+    description: A string constant or variable.
+
+  hash_type:
+    type: str
+    description: |
+      It supports the following algorithms:
+
+      - md5
+      - sha1
+      - sha224
+      - sha256
+      - sha384
+      - sha512
+      - sha3_224
+      - sha3_256
+      - sha3_384
+      - sha3_512

mesonbuild/ast/interpreter.py

@@ -247,6 +247,7 @@ def __init__(self, source_root: str, subdir: str, subproject: SubProject, subpro
                            'range': self.func_do_nothing,
                            'structured_sources': self.func_do_nothing,
                            'debug': self.func_do_nothing,
+                           'hash': self.func_do_nothing,
                            })
 
     def _unholder_args(self, args: T.Any, kwargs: T.Any) -> T.Tuple[T.Any, T.Any]:

mesonbuild/interpreter/interpreter.py

@@ -404,6 +404,7 @@ def build_func_dict(self) -> None:
                            'unset_variable': self.func_unset_variable,
                            'vcs_tag': self.func_vcs_tag,
                            'warning': self.func_warning,
+                           'hash': self.func_hash,
                            })
         if 'MESON_UNIT_TEST' in os.environ:
             self.funcs.update({'exception': self.func_exception})
@@ -1430,6 +1431,21 @@ def compatibility_sort_helper(s):
         if main_summary:
             main_summary.dump()
 
+    @typed_pos_args('hash', varargs=str, min_varargs=2 ,max_varargs=2)
+    @noKwargs
+    def func_hash(self, node: mparser.BaseNode, args: T.Tuple[T.List[str]], kwargs: 'TYPE_kwargs') -> str:
+        from hashlib import new
+        string, hash_type = args[0][0:2]
+        # For supported algorithms
+        # see https://docs.python.org/3/library/hashlib.html#hash-objects
+        if hash_type not in ['md5', 'sha1',
+                             'sha224', 'sha256', 'sha384', 'sha512',
+                             'sha3_224', 'sha3_256', 'sha3_384', 'sha3_512']:
+            raise InterpreterException(f'{hash_type} is not supported :(')
+        hash_obj = new(hash_type)
+        hash_obj.update(string.encode())
+        return hash_obj.hexdigest()
+
     @noArgsFlattening
     @FeatureNew('warning', '0.44.0')
     @noKwargs