SCons: Format buildsystem files with psf/black

Configured for a max line length of 120 characters.

psf/black is very opinionated and purposely doesn't leave much room for
configuration. The output is mostly OK so that should be fine for us,
but some things worth noting:

- Manually wrapped strings will be reflowed, so by using a line length
  of 120 for the sake of preserving readability for our long command
  calls, it also means that some manually wrapped strings are back on
  the same line and should be manually merged again.

- Code generators using string concatenation extensively look awful,
  since black puts each operand on a single line. We need to refactor
  these generators to use more pythonic string formatting, for which
  many options are available (`%`, `format` or f-strings).

- CI checks and a pre-commit hook will be added to ensure that future
  buildsystem changes are well-formatted.

(cherry picked from commit cd4e46ee65)

modules/mono/build_scripts/solution_builder.py

@@ -1,4 +1,3 @@
-
 import os
 
 
@@ -42,44 +41,44 @@ def find_msbuild_unix():
         hint_path = os.path.join(hint_dir, "msbuild")
         if os.path.isfile(hint_path):
             return hint_path
-        elif os.path.isfile(hint_path + '.exe'):
-            return hint_path + '.exe'
+        elif os.path.isfile(hint_path + ".exe"):
+            return hint_path + ".exe"
 
-    for hint_dir in os.environ['PATH'].split(os.pathsep):
+    for hint_dir in os.environ["PATH"].split(os.pathsep):
         hint_dir = hint_dir.strip('"')
         hint_path = os.path.join(hint_dir, "msbuild")
         if os.path.isfile(hint_path) and os.access(hint_path, os.X_OK):
             return hint_path
-        if os.path.isfile(hint_path + '.exe') and os.access(hint_path + '.exe', os.X_OK):
-            return hint_path + '.exe'
+        if os.path.isfile(hint_path + ".exe") and os.access(hint_path + ".exe", os.X_OK):
+            return hint_path + ".exe"
 
     return None
 
 
 def find_msbuild_windows(env):
-    from . mono_reg_utils import find_mono_root_dir, find_msbuild_tools_path_reg
+    from .mono_reg_utils import find_mono_root_dir, find_msbuild_tools_path_reg
 
-    mono_root = env['mono_prefix'] or find_mono_root_dir(env['bits'])
+    mono_root = env["mono_prefix"] or find_mono_root_dir(env["bits"])
 
     if not mono_root:
-        raise RuntimeError('Cannot find mono root directory')
+        raise RuntimeError("Cannot find mono root directory")
 
-    mono_bin_dir = os.path.join(mono_root, 'bin')
-    msbuild_mono = os.path.join(mono_bin_dir, 'msbuild.bat')
+    mono_bin_dir = os.path.join(mono_root, "bin")
+    msbuild_mono = os.path.join(mono_bin_dir, "msbuild.bat")
 
     msbuild_tools_path = find_msbuild_tools_path_reg()
 
     if msbuild_tools_path:
-        return (os.path.join(msbuild_tools_path, 'MSBuild.exe'), {})
+        return (os.path.join(msbuild_tools_path, "MSBuild.exe"), {})
 
     if os.path.isfile(msbuild_mono):
         # The (Csc/Vbc/Fsc)ToolExe environment variables are required when
         # building with Mono's MSBuild. They must point to the batch files
         # in Mono's bin directory to make sure they are executed with Mono.
         mono_msbuild_env = {
-            'CscToolExe': os.path.join(mono_bin_dir, 'csc.bat'),
-            'VbcToolExe': os.path.join(mono_bin_dir, 'vbc.bat'),
-            'FscToolExe': os.path.join(mono_bin_dir, 'fsharpc.bat')
+            "CscToolExe": os.path.join(mono_bin_dir, "csc.bat"),
+            "VbcToolExe": os.path.join(mono_bin_dir, "vbc.bat"),
+            "FscToolExe": os.path.join(mono_bin_dir, "fsharpc.bat"),
         }
         return (msbuild_mono, mono_msbuild_env)
 
@@ -88,7 +87,7 @@ def find_msbuild_windows(env):
 
 def run_command(command, args, env_override=None, name=None):
     def cmd_args_to_str(cmd_args):
-        return ' '.join([arg if not ' ' in arg else '"%s"' % arg for arg in cmd_args])
+        return " ".join([arg if not " " in arg else '"%s"' % arg for arg in cmd_args])
 
     args = [command] + args
 
@@ -99,6 +98,7 @@ def run_command(command, args, env_override=None, name=None):
         print("Running '%s': %s" % (name, cmd_args_to_str(args)))
 
     import subprocess
+
     try:
         if env_override is None:
             subprocess.check_call(args)
@@ -110,13 +110,13 @@ def run_command(command, args, env_override=None, name=None):
 
 def build_solution(env, solution_path, build_config, extra_msbuild_args=[]):
     global verbose
-    verbose = env['verbose']
+    verbose = env["verbose"]
 
     msbuild_env = os.environ.copy()
 
     # Needed when running from Developer Command Prompt for VS
-    if 'PLATFORM' in msbuild_env:
-        del msbuild_env['PLATFORM']
+    if "PLATFORM" in msbuild_env:
+        del msbuild_env["PLATFORM"]
 
     msbuild_args = []
 
@@ -124,7 +124,7 @@ def build_solution(env, solution_path, build_config, extra_msbuild_args=[]):
 
     if dotnet_cli:
         msbuild_path = dotnet_cli
-        msbuild_args += ["msbuild"] # `dotnet msbuild` command
+        msbuild_args += ["msbuild"]  # `dotnet msbuild` command
     else:
         # Find MSBuild
         if os.name == "nt":
@@ -138,7 +138,7 @@ def build_solution(env, solution_path, build_config, extra_msbuild_args=[]):
             if msbuild_path is None:
                 raise RuntimeError("Cannot find MSBuild executable")
 
-    print('MSBuild path: ' + msbuild_path)
+    print("MSBuild path: " + msbuild_path)
 
     # Build solution
 
@@ -147,4 +147,4 @@ def build_solution(env, solution_path, build_config, extra_msbuild_args=[]):
     msbuild_args += [solution_path, "/t:%s" % ",".join(targets), "/p:Configuration=" + build_config]
     msbuild_args += extra_msbuild_args
 
-    run_command(msbuild_path, msbuild_args, env_override=msbuild_env, name='msbuild')
+    run_command(msbuild_path, msbuild_args, env_override=msbuild_env, name="msbuild")