fix: detect VS2017 even on highly restricted environments

.gitignore

@@ -2,3 +2,4 @@ node_modules/
 npm-debug.log
 out/
 coverage/
+tools/*.exe

lib/gyp/platform/win.js

@@ -4,6 +4,7 @@ const gyp = require('../../gyp');
 const fs = gyp.bindings.fs;
 const path = gyp.bindings.path;
 const process = gyp.bindings.process;
+const execSync = gyp.bindings.execSync;
 
 const win = exports;
 
@@ -391,25 +392,84 @@ win.getOSBits = function getOSBits() {
     return 32;
 };
 
-function tryVS7(hostBits, target_arch) {
+function tryVS7_powershell() {
   try {
-    const psFile = path.join(__dirname,
-      '..', '..', '..', 'tools', 'Get-VSConfig.ps1');
-    const vsSetupRaw = gyp.bindings.execSync(`powershell ${psFile}`).toString();
+    const cs = path.join(__dirname, '..', '..', '..', 'tools', 'VSConfig.cs');
+    const cmd = `powershell -Command \
+      "&{ Add-Type -Path ${cs} ; [VisualStudioSetup]::Main()}"`;
+    const vsSetupRaw = execSync(cmd).toString();
     if (!vsSetupRaw) return;
+    const vsSetup = vsSetupRaw.split(/[\r|\n]+/g).reduce((s, l) => {
+      const lParts = l.split(': ');
+      if (lParts.length > 1) s[lParts[0]] = lParts[1];
+      return s;
+    }, {});
+    return vsSetup.InstallationPath;
+  } catch (e) {
+    gyp.bindings.log('Couldn\'t find VS7 with powershell' , e.message);
+  }
+}
+
+function tryVS7_CSC() {
+  const VREG = /.*v(\d+\.\d+).*/;
+  const dirCMD = 'dir /b /s %windir%\\Microsoft.NET\\Framework\\csc.exe';
+  try {
+    const files = execSync(dirCMD)
+      .toString()
+      .trim()
+      .split(/[\r|\n]+/g)
+      .map(f => [Number(f.replace(VREG, '$1')), f]);
+    const maxVer = Math.max.apply(Math, files.map(v => v[0]));
+    const cscPath = files.find(v => v[0] === maxVer)[1];
+    const toolsPath = path.join(__dirname, '..', '..', '..', 'tools');
+    const csPath = path.join(toolsPath, 'VSConfig.cs');
+    const exePath = path.join(toolsPath, 'VSConfig.exe');
+    execSync(`${cscPath} /out:${exePath} ${csPath}`);
+    const vsSetupRaw = execSync(exePath).toString();
     const vsSetup = vsSetupRaw.split(/[\r|\n]/g).reduce((s, l) => {
       const lParts = l.split(': ');
       if (lParts.length > 1) s[lParts[0]] = lParts[1];
       return s;
     }, {});
-    const VsDevCmd = path.join(vsSetup.InstallationPath,
-      'Common7', 'Tools', 'VsDevCmd.bat');
-    const argArch = target_arch === 'x64' ? 'amd64' : 'x86';
-    const argHost = hostBits === 64 ? 'amd64' : 'x86';
-    return `${VsDevCmd} -arch=${argArch} -host_arch=${argHost} -no_logo`;
+    return vsSetup.InstallationPath;
   } catch (e) {
+    gyp.bindings.log('Couldn\'t find VS7 with a compiled exe', e.message);
+  }
+}
+
+function tryVS7_registry() {
+  const magicKey = String.raw`HKLM\Software\Microsoft\VisualStudio\SxS\VS7`;
+  const magicQuery = `reg query ${magicKey} /reg:32`;
+  const qRet = execSync(magicQuery).toString().trim();
+  if (qRet.includes('ERROR')) {
+    gyp.bindings.log('Couldn\'t find VS7 in registry:(');
+    return;
+  }
+  const values = qRet.split(/[\r|\n]+/g).slice(1);
+  const ret = values.map(v => {
+    const parts = v.trim().replace(/\s+/g, ' ').split(' ');
+    return [Number(parts[0]), parts[2]];
+  });
+  if (!ret.length) {
+    gyp.bindings.log('Couldn\'t find VS7 in registry');
+    return;
+  }
+  const maxVer = Math.max.apply(Math, ret.map(v => v[0]));
+  return ret.find(v => v[0] === maxVer)[1];
+}
+
+win._forTesting = {tryVS7_powershell, tryVS7_CSC, tryVS7_registry};
+
+function tryVS7(hostBits, target_arch) {
+  const btPath = tryVS7_powershell() || tryVS7_CSC() || tryVS7_registry();
+  if (!btPath) {
     gyp.bindings.log('Couldn\'t find VS7 :(');
+    return;
   }
+  const VsDevCmd = path.join(btPath, 'Common7', 'Tools', 'VsDevCmd.bat');
+  const argArch = target_arch === 'x64' ? 'amd64' : 'x86';
+  const argHost = hostBits === 64 ? 'amd64' : 'x86';
+  return `${VsDevCmd} -arch=${argArch} -host_arch=${argHost} -no_logo`;
 }
 
 function findOldVcVarsFile(hostBits, target_arch) {

test/platform-win-test.js

@@ -228,6 +228,23 @@ describe('gyp.platform.win', () => {
   if (process.platform === 'win32') {
     describe('genEnvironment', function () {
       this.timeout(20000);
+
+      it('try with powershell', () => {
+        const path = win._forTesting.tryVS7_powershell();
+        assert(path.includes('BuildTools'));
+      });
+
+      it('try with csc', () => {
+        const path = win._forTesting.tryVS7_CSC();
+        assert(path.includes('BuildTools'));
+      });
+
+      it('try with registry', () => {
+        const path = win._forTesting.tryVS7_registry();
+        assert(path.includes('BuildTools'));
+
+      });
+
       it('resolve for x64', () => {
         const env = win.resolveDevEnvironment('x64');
         assert(env, 'didn\'t get ENVIRONMENT :(');

tools/Get-VSConfig.ps1 → tools/VSConfig.cs

@@ -1,4 +1,3 @@
-$Source = @"
 using System;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -171,6 +170,3 @@ private static void PrintInstance(ISetupInstance2 setupInstance2)
         Console.WriteLine();
     }
 }
-"@
-Add-Type -TypeDefinition $Source -Language CSharp
-[VisualStudioSetup]::Main()