Detect files with trailing space

On Windows, if you accidently add a space at the end of a file name, like
`files('myfile.txt ')`, the file is not reported as missing, because of
the normalization performed by the OS. However, ninja will reference it
with the trailing space, and will fail because the file does not exist.

See python/cpython#115104 for reference.

Author: bruchar1

mesonbuild/interpreter/interpreter.py

@@ -664,6 +664,9 @@ def func_import(self, node: mparser.BaseNode, args: T.Tuple[str],
     @typed_pos_args('files', varargs=str)
     @noKwargs
     def func_files(self, node: mparser.FunctionNode, args: T.Tuple[T.List[str]], kwargs: 'TYPE_kwargs') -> T.List[mesonlib.File]:
+        for filename in args[0]:
+            if filename.endswith(' '):
+                raise MesonException(f'{filename!r} ends with a space. This is probably an error.', file=node.filename, lineno=node.lineno, colno=node.colno)
         return self.source_strings_to_files(args[0])
 
     @noPosargs

mesonbuild/utils/universal.py

@@ -398,7 +398,7 @@ def __repr__(self) -> str:
 
     @staticmethod
     @lru_cache(maxsize=None)
-    def from_source_file(source_root: str, subdir: str, fname: str) -> 'File':
+    def from_source_file(source_root: str, subdir: str, fname: str) -> File:
         if not os.path.isfile(os.path.join(source_root, subdir, fname)):
             raise MesonException(f'File {fname} does not exist.')
         return File(False, subdir, fname)

test cases/failing/2 missing file/test.json

@@ -1,7 +1,7 @@
 {
   "stdout": [
     {
-      "line": "test cases/failing/2 missing file/meson.build:3:0: ERROR: File missing.c does not exist."
+      "line": "test cases/failing/2 missing file/meson.build:3:0: ERROR: File 'missing.c' does not exist."
     }
   ]
 }

test cases/failing/65 skip only subdir/test.json

@@ -1,7 +1,7 @@
 {
   "stdout": [
     {
-      "line": "test cases/failing/65 skip only subdir/meson.build:8:0: ERROR: File main.cpp does not exist."
+      "line": "test cases/failing/65 skip only subdir/meson.build:8:0: ERROR: File 'main.cpp' does not exist."
     }
   ]
 }

test cases/failing/9 missing extra file/test.json

@@ -1,7 +1,7 @@
 {
   "stdout": [
     {
-      "line": "test cases/failing/9 missing extra file/meson.build:3:0: ERROR: File missing.txt does not exist."
+      "line": "test cases/failing/9 missing extra file/meson.build:3:0: ERROR: File 'missing.txt' does not exist."
     }
   ]
 }