Fix MSBuild toolset/SDK detection under Wine

msbuild <project>.vcxproj previously failed with MSB8020 ("build tools for
vNNN cannot be found") because MSBuild's own toolset/SDK resolution reads
a different set of environment variables than cl/link/lib do directly
(VCInstallDir_<N>, VCToolsInstallDir_<N>, VsInstallRoot,
WindowsSdkDir_10, WindowsTargetPlatformVersion, DisableRegistryUse, etc) -
none of which the generic INCLUDE/LIB/WINEPATH env covered.

Added msbuildEnv, populated for every MSBuild toolset generation actually
present under MSBuild/Microsoft/VC/v*, and wired into the msbuild wrapper.

Verified end-to-end: msbuild successfully builds ocornut/imgui's
example_win32_directx11.vcxproj (retargeted from its original v141
PlatformToolset to this install's v145) - compiles all 8 sources and
links against d3d11.lib/d3dcompiler.lib/dxgi.lib, producing a valid
PE32+ executable.

internal/wineenv/paths.go

@@ -16,6 +16,14 @@ type Paths struct {
 	SDKBinDir     string // <dest>/kits/10/bin/<sdkver>/<host> - mc/midl/mt/rc live here
 	MSBuildBinDir string // <dest>/MSBuild/Current/Bin/<dotnetHost> - MSBuild.exe lives here
 
+	// Windows-notation ("z:\...") equivalents of the paths above, needed to
+	// populate the MSBuild-specific environment variables its toolset/SDK
+	// detection props read (see msbuildEnv in the wrapper package).
+	BaseWin     string // z:\<dest>
+	MSVCBaseWin string // z:\<dest>\vc
+	MSVCDirWin  string // z:\<dest>\vc\tools\msvc\<ver>
+	SDKBaseWin  string // z:\<dest>\kits\10
+
 	Include          string
 	Lib              string
 	LibPath          string
@@ -89,6 +97,11 @@ func NewPaths(cfg *Config, baseUnix string) *Paths {
 		SDKBinDir:     sdkBinDir,
 		MSBuildBinDir: msbuildBinDir,
 
+		BaseWin:     winBase,
+		MSVCBaseWin: msvcBase,
+		MSVCDirWin:  msvcDirWin,
+		SDKBaseWin:  sdkBase,
+
 		Include:          include,
 		Lib:              lib,
 		LibPath:          lib,

internal/wrapper/msbuildenv.go

@@ -0,0 +1,86 @@
+package wrapper
+
+import (
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/Cheviiot/msvc-go-wine/internal/wineenv"
+)
+
+var reToolsetDir = regexp.MustCompile(`^v(\d+)$`)
+
+// msbuildEnv returns the extra environment variables MSBuild's own
+// SDK/toolset-detection property sheets need. The generic INCLUDE/LIB/
+// WINEPATH set by buildEnv are enough for cl/link/lib invoked directly, but
+// MSBuild resolves the compiler location and Windows SDK through a
+// different, registry-oriented mechanism - DisableRegistryUse=true
+// redirects that lookup to these variables instead of a (nonexistent)
+// Windows Registry.
+func msbuildEnv(cfg *wineenv.Config, paths *wineenv.Paths) map[string]string {
+	env := map[string]string{
+		"DisableRegistryUse": "true",
+		"VCToolsVersion":     cfg.MSVCVer,
+		"VsInstallRoot":      paths.BaseWin + `\`,
+		"VSInstallDir":       paths.BaseWin + `\`,
+
+		"MicrosoftKitRoot":                          paths.BaseWin + `\`,
+		"SDKReferenceDirectoryRoot":                 paths.BaseWin + `\`,
+		"SDKExtensionDirectoryRoot":                 paths.BaseWin + `\`,
+		"MSBUILDSDKREFERENCEDIRECTORY":              paths.BaseWin + `\`,
+		"MSBUILDMULTIPLATFORMSDKREFERENCEDIRECTORY": paths.BaseWin + `\`,
+
+		"WindowsSdkDir_10":             paths.SDKBaseWin + `\`,
+		"UniversalCRTSdkDir_10":        paths.SDKBaseWin + `\`,
+		"WindowsSdkDir":                paths.SDKBaseWin + `\`,
+		"UniversalCRTSdkDir":           paths.SDKBaseWin + `\`,
+		"WindowsTargetPlatformVersion": cfg.SDKVer,
+		"UCRTContentRoot":              paths.SDKBaseWin + `\`,
+		"NETFXKitsDir":                 paths.SDKBaseWin + `\`,
+		"NETFXSDKDir":                  paths.SDKBaseWin + `\`,
+
+		// WDK-specific properties; harmless when not building a driver.
+		"WDKKitVersion":            "10",
+		"Driver_SpectreMitigation": "false",
+		"SignMode":                 "off",
+		"Inf2CatNoCatalog":         "true",
+		"ApiValidator_Enable":      "False",
+
+		"Platform": msbuildPlatform(cfg.Arch),
+	}
+
+	// Microsoft.Cpp.props resolves the compiler/toolset location through
+	// VCInstallDir_<N>/VCToolsInstallDir_<N>, where <N> is whatever numeric
+	// suffix the installed MSBuild toolset property sheets use (e.g.
+	// .../MSBuild/Microsoft/VC/v180 -> "180"). Populate every one actually
+	// present, so a project pinned to any of them resolves to the one real
+	// toolchain that's installed.
+	matches, _ := filepath.Glob(filepath.Join(paths.BaseUnix, "MSBuild", "Microsoft", "VC", "v*"))
+	for _, m := range matches {
+		sub := reToolsetDir.FindStringSubmatch(filepath.Base(m))
+		if sub == nil {
+			continue
+		}
+		env["VCInstallDir_"+sub[1]] = paths.MSVCBaseWin + `\`
+		env["VCToolsInstallDir_"+sub[1]] = paths.MSVCDirWin + `\`
+	}
+
+	if strings.HasSuffix(paths.MSBuildBinDir, "amd64") {
+		env["PreferredToolArchitecture"] = "x64"
+	}
+
+	return env
+}
+
+func msbuildPlatform(arch string) string {
+	switch arch {
+	case "x86":
+		return "Win32"
+	case "arm":
+		return "ARM"
+	case "arm64":
+		return "ARM64"
+	default:
+		return arch
+	}
+}

internal/wrapper/run.go

@@ -70,9 +70,15 @@ func Run(tool string, args []string) int {
 	var exitCode int
 	switch {
 	case s.rawStdout:
-		// MSBuild: skip all filtering/toolrelay, inherit stdio directly.
+		// MSBuild: skip all filtering/toolrelay, inherit stdio directly, and
+		// add the extra environment MSBuild's own toolset/SDK-detection
+		// props need on top of the generic INCLUDE/LIB/WINEPATH.
 		cmd := exec.Command(wineBin, append([]string{toolExePath}, rewritten...)...)
-		cmd.Env = buildEnv(paths)
+		env := buildEnv(paths)
+		for k, v := range msbuildEnv(cfg, paths) {
+			env = append(env, k+"="+v)
+		}
+		cmd.Env = env
 		cmd.Stdin = os.Stdin
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr