C#: Move marshaling logic and generated glue to C#

We will be progressively moving most code to C#.
The plan is to only use Mono's embedding APIs to set things at launch.
This will make it much easier to later support CoreCLR too which
doesn't have rich embedding APIs.

Additionally the code in C# is more maintainable and makes it easier
to implement new features, e.g.: runtime codegen which we could use to
avoid using reflection for marshaling everytime a field, property or
method is accessed.

SOME NOTES ON INTEROP

We make the same assumptions as GDNative about the size of the Godot
structures we use. We take it a bit further by also assuming the layout
of fields in some cases, which is riskier but let's us squeeze out some
performance by avoiding unnecessary managed to native calls.

Code that deals with native structs is less safe than before as there's
no RAII and copy constructors in C#. It's like using the GDNative C API
directly. One has to take special care to free values they own.
Perhaps we could use roslyn analyzers to check this, but I don't know
any that uses attributes to determine what's owned or borrowed.

As to why we maily use pointers for native structs instead of ref/out:
- AFAIK (and confirmed with a benchmark) ref/out are pinned
  during P/Invoke calls and that has a cost.
- Native struct fields can't be ref/out in the first place.
- A `using` local can't be passed as ref/out, only `in`. Calling a
  method or property on an `in` value makes a silent copy, so we want
  to avoid `in`.

REGARDING THE BUILD SYSTEM

There's no longer a `mono_glue=yes/no` SCons options. We no longer
need to build with `mono_glue=no`, generate the glue and then build
again with `mono_glue=yes`. We build only once and generate the glue
(which is in C# now).
However, SCons no longer builds the C# projects for us. Instead one
must run `build_assemblies.py`, e.g.:
```sh
%godot_src_root%/modules/mono/build_scripts/build_assemblies.py \
        --godot-output-dir=%godot_src_root%/bin \
        --godot-target=release_debug`
```
We could turn this into a custom build target, but I don't know how
to do that with SCons (it's possible with Meson).

OTHER NOTES

Most of the moved code doesn't follow the C# naming convention and
still has the word Mono in the names despite no longer dealing with
Mono's embedding APIs. This is just temporary while transitioning,
to make it easier to understand what was moved where.

6 files changed, 306 insertions, 338 deletions

diff --git a/modules/mono/build_scripts/api_solution_build.py b/modules/mono/build_scripts/api_solution_build.py
deleted file mode 100644
index 9abac22df6..0000000000
--- a/modules/mono/build_scripts/api_solution_build.py
+++ /dev/null
@@ -1,80 +0,0 @@
-# Build the Godot API solution
-
-import os
-
-from SCons.Script import Dir
-
-
-def build_api_solution(source, target, env):
-    # source and target elements are of type SCons.Node.FS.File, hence why we convert them to str
-
-    module_dir = env["module_dir"]
-
-    solution_path = os.path.join(module_dir, "glue/GodotSharp/GodotSharp.sln")
-
-    build_config = env["solution_build_config"]
-
-    extra_msbuild_args = ["/p:NoWarn=1591"]  # Ignore missing documentation warnings
-
-    from .solution_builder import build_solution
-
-    build_solution(env, solution_path, build_config, extra_msbuild_args=extra_msbuild_args)
-
-    # Copy targets
-
-    core_src_dir = os.path.abspath(os.path.join(solution_path, os.pardir, "GodotSharp", "bin", build_config))
-    editor_src_dir = os.path.abspath(os.path.join(solution_path, os.pardir, "GodotSharpEditor", "bin", build_config))
-
-    dst_dir = os.path.abspath(os.path.join(str(target[0]), os.pardir))
-
-    if not os.path.isdir(dst_dir):
-        assert not os.path.isfile(dst_dir)
-        os.makedirs(dst_dir)
-
-    def copy_target(target_path):
-        from shutil import copy
-
-        filename = os.path.basename(target_path)
-
-        src_path = os.path.join(core_src_dir, filename)
-        if not os.path.isfile(src_path):
-            src_path = os.path.join(editor_src_dir, filename)
-
-        copy(src_path, target_path)
-
-    for scons_target in target:
-        copy_target(str(scons_target))
-
-
-def build(env_mono):
-    assert env_mono["tools"]
-
-    target_filenames = [
-        "GodotSharp.dll",
-        "GodotSharp.pdb",
-        "GodotSharp.xml",
-        "GodotSharpEditor.dll",
-        "GodotSharpEditor.pdb",
-        "GodotSharpEditor.xml",
-    ]
-
-    depend_cmd = []
-
-    for build_config in ["Debug", "Release"]:
-        output_dir = Dir("#bin").abspath
-        editor_api_dir = os.path.join(output_dir, "GodotSharp", "Api", build_config)
-
-        targets = [os.path.join(editor_api_dir, filename) for filename in target_filenames]
-
-        cmd = env_mono.CommandNoCache(
-            targets, depend_cmd, build_api_solution, module_dir=os.getcwd(), solution_build_config=build_config
-        )
-        env_mono.AlwaysBuild(cmd)
-
-        # Make the Release build of the API solution depend on the Debug build.
-        # We do this in order to prevent SCons from building them in parallel,
-        # which can freak out MSBuild. In many cases, one of the builds would
-        # hang indefinitely requiring a key to be pressed for it to continue.
-        depend_cmd = cmd
-
-    return depend_cmd
diff --git a/modules/mono/build_scripts/build_assemblies.py b/modules/mono/build_scripts/build_assemblies.py
new file mode 100755
index 0000000000..dd96f40f6b
--- /dev/null
+++ b/modules/mono/build_scripts/build_assemblies.py
@@ -0,0 +1,306 @@
+#!/usr/bin/python3
+
+import os
+import os.path
+import shlex
+import subprocess
+from dataclasses import dataclass
+
+
+def find_dotnet_cli():
+    if os.name == "nt":
+        for hint_dir in os.environ["PATH"].split(os.pathsep):
+            hint_dir = hint_dir.strip('"')
+            hint_path = os.path.join(hint_dir, "dotnet")
+            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"
+    else:
+        for hint_dir in os.environ["PATH"].split(os.pathsep):
+            hint_dir = hint_dir.strip('"')
+            hint_path = os.path.join(hint_dir, "dotnet")
+            if os.path.isfile(hint_path) and os.access(hint_path, os.X_OK):
+                return hint_path
+
+
+def find_msbuild_standalone_windows():
+    msbuild_tools_path = find_msbuild_tools_path_reg()
+
+    if msbuild_tools_path:
+        return os.path.join(msbuild_tools_path, "MSBuild.exe")
+
+    return None
+
+
+def find_msbuild_mono_windows(mono_prefix):
+    assert mono_prefix is not None
+
+    mono_bin_dir = os.path.join(mono_prefix, "bin")
+    msbuild_mono = os.path.join(mono_bin_dir, "msbuild.bat")
+
+    if os.path.isfile(msbuild_mono):
+        return msbuild_mono
+
+    return None
+
+
+def find_msbuild_mono_unix():
+    import sys
+
+    hint_dirs = []
+    if sys.platform == "darwin":
+        hint_dirs[:0] = [
+            "/Library/Frameworks/Mono.framework/Versions/Current/bin",
+            "/usr/local/var/homebrew/linked/mono/bin",
+        ]
+
+    for hint_dir in hint_dirs:
+        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"
+
+    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"
+
+    return None
+
+
+def find_msbuild_tools_path_reg():
+    import subprocess
+
+    program_files = os.getenv("PROGRAMFILES(X86)")
+    if not program_files:
+        program_files = os.getenv("PROGRAMFILES")
+    vswhere = os.path.join(program_files, "Microsoft Visual Studio", "Installer", "vswhere.exe")
+
+    vswhere_args = ["-latest", "-products", "*", "-requires", "Microsoft.Component.MSBuild"]
+
+    try:
+        lines = subprocess.check_output([vswhere] + vswhere_args).splitlines()
+
+        for line in lines:
+            parts = line.decode("utf-8").split(":", 1)
+
+            if len(parts) < 2 or parts[0] != "installationPath":
+                continue
+
+            val = parts[1].strip()
+
+            if not val:
+                raise ValueError("Value of `installationPath` entry is empty")
+
+            # Since VS2019, the directory is simply named "Current"
+            msbuild_dir = os.path.join(val, "MSBuild", "Current", "Bin")
+            if os.path.isdir(msbuild_dir):
+                return msbuild_dir
+
+            # Directory name "15.0" is used in VS 2017
+            return os.path.join(val, "MSBuild", "15.0", "Bin")
+
+        raise ValueError("Cannot find `installationPath` entry")
+    except ValueError as e:
+        print("Error reading output from vswhere: " + str(e))
+    except OSError:
+        pass  # Fine, vswhere not found
+    except (subprocess.CalledProcessError, OSError):
+        pass
+
+
+@dataclass
+class ToolsLocation:
+    dotnet_cli: str = ""
+    msbuild_standalone: str = ""
+    msbuild_mono: str = ""
+    mono_bin_dir: str = ""
+
+
+def find_any_msbuild_tool(mono_prefix):
+    # Preference order: dotnet CLI > Standalone MSBuild > Mono's MSBuild
+
+    # Find dotnet CLI
+    dotnet_cli = find_dotnet_cli()
+    if dotnet_cli:
+        return ToolsLocation(dotnet_cli=dotnet_cli)
+
+    # Find standalone MSBuild
+    if os.name == "nt":
+        msbuild_standalone = find_msbuild_standalone_windows()
+        if msbuild_standalone:
+            return ToolsLocation(msbuild_standalone=msbuild_standalone)
+
+    if mono_prefix:
+        # Find Mono's MSBuild
+        if os.name == "nt":
+            msbuild_mono = find_msbuild_mono_windows(mono_prefix)
+            if msbuild_mono:
+                return ToolsLocation(msbuild_mono=msbuild_mono)
+        else:
+            msbuild_mono = find_msbuild_mono_unix()
+            if msbuild_mono:
+                return ToolsLocation(msbuild_mono=msbuild_mono)
+
+    return None
+
+
+def run_msbuild(tools: ToolsLocation, sln: str, msbuild_args: [str] = None):
+    if msbuild_args is None:
+        msbuild_args = []
+
+    using_msbuild_mono = False
+
+    # Preference order: dotnet CLI > Standalone MSBuild > Mono's MSBuild
+    if tools.dotnet_cli:
+        args = [tools.dotnet_cli, "msbuild"]
+    elif tools.msbuild_standalone:
+        args = [tools.msbuild_standalone]
+    elif tools.msbuild_mono:
+        args = [tools.msbuild_mono]
+        using_msbuild_mono = True
+    else:
+        raise RuntimeError("Path to MSBuild or dotnet CLI not provided.")
+
+    args += [sln]
+
+    if len(msbuild_args) > 0:
+        args += msbuild_args
+
+    print("Running MSBuild: ", " ".join(shlex.quote(arg) for arg in args), flush=True)
+
+    msbuild_env = os.environ.copy()
+
+    # Needed when running from Developer Command Prompt for VS
+    if "PLATFORM" in msbuild_env:
+        del msbuild_env["PLATFORM"]
+
+    if using_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.
+        msbuild_env.update(
+            {
+                "CscToolExe": os.path.join(tools.mono_bin_dir, "csc.bat"),
+                "VbcToolExe": os.path.join(tools.mono_bin_dir, "vbc.bat"),
+                "FscToolExe": os.path.join(tools.mono_bin_dir, "fsharpc.bat"),
+            }
+        )
+
+    return subprocess.call(args, env=msbuild_env)
+
+
+def build_godot_api(msbuild_tool, module_dir, output_dir):
+    target_filenames = [
+        "GodotSharp.dll",
+        "GodotSharp.pdb",
+        "GodotSharp.xml",
+        "GodotSharpEditor.dll",
+        "GodotSharpEditor.pdb",
+        "GodotSharpEditor.xml",
+    ]
+
+    for build_config in ["Debug", "Release"]:
+        editor_api_dir = os.path.join(output_dir, "GodotSharp", "Api", build_config)
+
+        targets = [os.path.join(editor_api_dir, filename) for filename in target_filenames]
+
+        sln = os.path.join(module_dir, "glue/GodotSharp/GodotSharp.sln")
+        exit_code = run_msbuild(
+            msbuild_tool,
+            sln=sln,
+            msbuild_args=["/restore", "/t:Build", "/p:Configuration=" + build_config, "/p:NoWarn=1591"],
+        )
+        if exit_code != 0:
+            return exit_code
+
+        # Copy targets
+
+        core_src_dir = os.path.abspath(os.path.join(sln, os.pardir, "GodotSharp", "bin", build_config))
+        editor_src_dir = os.path.abspath(os.path.join(sln, os.pardir, "GodotSharpEditor", "bin", build_config))
+
+        if not os.path.isdir(editor_api_dir):
+            assert not os.path.isfile(editor_api_dir)
+            os.makedirs(editor_api_dir)
+
+        def copy_target(target_path):
+            from shutil import copy
+
+            filename = os.path.basename(target_path)
+
+            src_path = os.path.join(core_src_dir, filename)
+            if not os.path.isfile(src_path):
+                src_path = os.path.join(editor_src_dir, filename)
+
+            print(f"Copying assembly to {target_path}...")
+            copy(src_path, target_path)
+
+        for scons_target in targets:
+            copy_target(scons_target)
+
+    return 0
+
+
+def build_all(msbuild_tool, module_dir, output_dir, dev_debug, godot_platform):
+    # Godot API
+    exit_code = build_godot_api(msbuild_tool, module_dir, output_dir)
+    if exit_code != 0:
+        return exit_code
+
+    # GodotTools
+    sln = os.path.join(module_dir, "editor/GodotTools/GodotTools.sln")
+    args = ["/restore", "/t:Build", "/p:Configuration=" + ("Debug" if dev_debug else "Release")] + (
+        ["/p:GodotPlatform=" + godot_platform] if godot_platform else []
+    )
+    exit_code = run_msbuild(msbuild_tool, sln=sln, msbuild_args=args)
+    if exit_code != 0:
+        return exit_code
+
+    # Godot.NET.Sdk
+    sln = os.path.join(module_dir, "editor/Godot.NET.Sdk/Godot.NET.Sdk.sln")
+    exit_code = run_msbuild(msbuild_tool, sln=sln, msbuild_args=["/restore", "/t:Build", "/p:Configuration=Release"])
+    if exit_code != 0:
+        return exit_code
+
+    return 0
+
+
+def main():
+    import argparse
+    import sys
+
+    parser = argparse.ArgumentParser(description="Builds all Godot .NET solutions")
+    parser.add_argument("--godot-output-dir", type=str, required=True)
+    parser.add_argument(
+        "--dev-debug",
+        action="store_true",
+        default=False,
+        help="Build GodotTools and Godot.NET.Sdk with 'Configuration=Debug'",
+    )
+    parser.add_argument("--godot-platform", type=str, default="")
+    parser.add_argument("--mono-prefix", type=str, default="")
+
+    args = parser.parse_args()
+
+    this_script_dir = os.path.dirname(os.path.realpath(__file__))
+    module_dir = os.path.abspath(os.path.join(this_script_dir, os.pardir))
+
+    output_dir = os.path.abspath(args.godot_output_dir)
+
+    msbuild_tool = find_any_msbuild_tool(args.mono_prefix)
+
+    if msbuild_tool is None:
+        print("Unable to find MSBuild")
+        sys.exit(1)
+
+    exit_code = build_all(msbuild_tool, module_dir, output_dir, args.godot_platform, args.dev_debug)
+    sys.exit(exit_code)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/modules/mono/build_scripts/gen_cs_glue_version.py b/modules/mono/build_scripts/gen_cs_glue_version.py
deleted file mode 100644
index 98bbb4d9be..0000000000
--- a/modules/mono/build_scripts/gen_cs_glue_version.py
+++ /dev/null
@@ -1,20 +0,0 @@
-def generate_header(solution_dir, version_header_dst):
-    import os
-
-    latest_mtime = 0
-    for root, dirs, files in os.walk(solution_dir, topdown=True):
-        dirs[:] = [d for d in dirs if d not in ["Generated"]]  # Ignored generated files
-        files = [f for f in files if f.endswith(".cs")]
-        for file in files:
-            filepath = os.path.join(root, file)
-            mtime = os.path.getmtime(filepath)
-            latest_mtime = mtime if mtime > latest_mtime else latest_mtime
-
-    glue_version = int(latest_mtime)  # The latest modified time will do for now
-
-    with open(version_header_dst, "w") as version_header:
-        version_header.write("/* THIS FILE IS GENERATED DO NOT EDIT */\n")
-        version_header.write("#ifndef CS_GLUE_VERSION_H\n")
-        version_header.write("#define CS_GLUE_VERSION_H\n\n")
-        version_header.write("#define CS_GLUE_VERSION UINT32_C(" + str(glue_version) + ")\n")
-        version_header.write("\n#endif // CS_GLUE_VERSION_H\n")
diff --git a/modules/mono/build_scripts/godot_net_sdk_build.py b/modules/mono/build_scripts/godot_net_sdk_build.py
deleted file mode 100644
index 8c5a60d2db..0000000000
--- a/modules/mono/build_scripts/godot_net_sdk_build.py
+++ /dev/null
@@ -1,55 +0,0 @@
-# Build Godot.NET.Sdk solution
-
-import os
-
-from SCons.Script import Dir
-
-
-def build_godot_net_sdk(source, target, env):
-    # source and target elements are of type SCons.Node.FS.File, hence why we convert them to str
-
-    module_dir = env["module_dir"]
-
-    solution_path = os.path.join(module_dir, "editor/Godot.NET.Sdk/Godot.NET.Sdk.sln")
-    build_config = "Release"
-
-    from .solution_builder import build_solution
-
-    extra_msbuild_args = ["/p:GodotPlatform=" + env["platform"]]
-
-    build_solution(env, solution_path, build_config, extra_msbuild_args)
-    # No need to copy targets. The Godot.NET.Sdk csproj takes care of copying them.
-
-
-def get_nupkgs_versions(props_file):
-    import xml.etree.ElementTree as ET
-
-    tree = ET.parse(props_file)
-    root = tree.getroot()
-
-    return {
-        "Godot.NET.Sdk": root.find("./PropertyGroup/PackageVersion_Godot_NET_Sdk").text.strip(),
-        "Godot.SourceGenerators": root.find("./PropertyGroup/PackageVersion_Godot_SourceGenerators").text.strip(),
-    }
-
-
-def build(env_mono):
-    assert env_mono["tools"]
-
-    output_dir = Dir("#bin").abspath
-    editor_tools_dir = os.path.join(output_dir, "GodotSharp", "Tools")
-    nupkgs_dir = os.path.join(editor_tools_dir, "nupkgs")
-
-    module_dir = os.getcwd()
-
-    nupkgs_versions = get_nupkgs_versions(os.path.join(module_dir, "SdkPackageVersions.props"))
-
-    target_filenames = [
-        "Godot.NET.Sdk.%s.nupkg" % nupkgs_versions["Godot.NET.Sdk"],
-        "Godot.SourceGenerators.%s.nupkg" % nupkgs_versions["Godot.SourceGenerators"],
-    ]
-
-    targets = [os.path.join(nupkgs_dir, filename) for filename in target_filenames]
-
-    cmd = env_mono.CommandNoCache(targets, [], build_godot_net_sdk, module_dir=module_dir)
-    env_mono.AlwaysBuild(cmd)
diff --git a/modules/mono/build_scripts/godot_tools_build.py b/modules/mono/build_scripts/godot_tools_build.py
deleted file mode 100644
index 3bbbf29d3b..0000000000
--- a/modules/mono/build_scripts/godot_tools_build.py
+++ /dev/null
@@ -1,38 +0,0 @@
-# Build GodotTools solution
-
-import os
-
-from SCons.Script import Dir
-
-
-def build_godot_tools(source, target, env):
-    # source and target elements are of type SCons.Node.FS.File, hence why we convert them to str
-
-    module_dir = env["module_dir"]
-
-    solution_path = os.path.join(module_dir, "editor/GodotTools/GodotTools.sln")
-    build_config = "Debug" if env["target"] == "debug" else "Release"
-
-    from .solution_builder import build_solution
-
-    extra_msbuild_args = ["/p:GodotPlatform=" + env["platform"]]
-
-    build_solution(env, solution_path, build_config, extra_msbuild_args)
-    # No need to copy targets. The GodotTools csproj takes care of copying them.
-
-
-def build(env_mono, api_sln_cmd):
-    assert env_mono["tools"]
-
-    output_dir = Dir("#bin").abspath
-    editor_tools_dir = os.path.join(output_dir, "GodotSharp", "Tools")
-
-    target_filenames = ["GodotTools.dll"]
-
-    if env_mono["target"] == "debug":
-        target_filenames += ["GodotTools.pdb"]
-
-    targets = [os.path.join(editor_tools_dir, filename) for filename in target_filenames]
-
-    cmd = env_mono.CommandNoCache(targets, api_sln_cmd, build_godot_tools, module_dir=os.getcwd())
-    env_mono.AlwaysBuild(cmd)
diff --git a/modules/mono/build_scripts/solution_builder.py b/modules/mono/build_scripts/solution_builder.py
deleted file mode 100644
index 6a621c3c8b..0000000000
--- a/modules/mono/build_scripts/solution_builder.py
+++ /dev/null
@@ -1,145 +0,0 @@
-import os
-
-
-verbose = False
-
-
-def find_dotnet_cli():
-    import os.path
-
-    if os.name == "nt":
-        for hint_dir in os.environ["PATH"].split(os.pathsep):
-            hint_dir = hint_dir.strip('"')
-            hint_path = os.path.join(hint_dir, "dotnet")
-            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"
-    else:
-        for hint_dir in os.environ["PATH"].split(os.pathsep):
-            hint_dir = hint_dir.strip('"')
-            hint_path = os.path.join(hint_dir, "dotnet")
-            if os.path.isfile(hint_path) and os.access(hint_path, os.X_OK):
-                return hint_path
-
-
-def find_msbuild_unix():
-    import os.path
-    import sys
-
-    hint_dirs = []
-    if sys.platform == "darwin":
-        hint_dirs[:0] = [
-            "/Library/Frameworks/Mono.framework/Versions/Current/bin",
-            "/usr/local/var/homebrew/linked/mono/bin",
-        ]
-
-    for hint_dir in hint_dirs:
-        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"
-
-    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"
-
-    return None
-
-
-def find_msbuild_windows(env):
-    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"])
-
-    if not mono_root:
-        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")
-
-    msbuild_tools_path = find_msbuild_tools_path_reg()
-
-    if msbuild_tools_path:
-        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"),
-        }
-        return (msbuild_mono, mono_msbuild_env)
-
-    return None
-
-
-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])
-
-    args = [command] + args
-
-    if name is None:
-        name = os.path.basename(command)
-
-    if verbose:
-        print("Running '%s': %s" % (name, cmd_args_to_str(args)))
-
-    import subprocess
-
-    try:
-        if env_override is None:
-            subprocess.check_call(args)
-        else:
-            subprocess.check_call(args, env=env_override)
-    except subprocess.CalledProcessError as e:
-        raise RuntimeError("'%s' exited with error code: %s" % (name, e.returncode))
-
-
-def build_solution(env, solution_path, build_config, extra_msbuild_args=[]):
-    global 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"]
-
-    msbuild_args = []
-
-    dotnet_cli = find_dotnet_cli()
-
-    if dotnet_cli:
-        msbuild_path = dotnet_cli
-        msbuild_args += ["msbuild"]  # `dotnet msbuild` command
-    else:
-        # Find MSBuild
-        if os.name == "nt":
-            msbuild_info = find_msbuild_windows(env)
-            if msbuild_info is None:
-                raise RuntimeError("Cannot find MSBuild executable")
-            msbuild_path = msbuild_info[0]
-            msbuild_env.update(msbuild_info[1])
-        else:
-            msbuild_path = find_msbuild_unix()
-            if msbuild_path is None:
-                raise RuntimeError("Cannot find MSBuild executable")
-
-    print("MSBuild path: " + msbuild_path)
-
-    # Build solution
-
-    msbuild_args += [solution_path, "/restore", "/t:Build", "/p:Configuration=" + build_config]
-    msbuild_args += extra_msbuild_args
-
-    run_command(msbuild_path, msbuild_args, env_override=msbuild_env, name="msbuild")