C#: Unset Platform env variable when invoking vcvarsall.bat

Author: hvitved

csharp/autobuilder/Semmle.Autobuild/CommandBuilder.cs

@@ -169,7 +169,7 @@ void NextCommand()
                 arguments.Append(" &&");
         }
 
-        public CommandBuilder RunCommand(string exe, string argumentsOpt = null)
+        public CommandBuilder RunCommand(string exe, string argumentsOpt = null, bool quoteExe = true)
         {
             var (exe0, arg0) =
                 escapingMode == EscapeMode.Process && exe.EndsWith(".exe", System.StringComparison.Ordinal)
@@ -183,7 +183,10 @@ public CommandBuilder RunCommand(string exe, string argumentsOpt = null)
             }
             else
             {
-                QuoteArgument(exe0);
+                if (quoteExe)
+                    QuoteArgument(exe0);
+                else
+                    Argument(exe0);
             }
             Argument(arg0);
             Argument(argumentsOpt);

csharp/autobuilder/Semmle.Autobuild/MsBuildRule.cs

@@ -57,7 +57,14 @@ public BuildScript Analyse(Autobuilder builder, bool auto)
                 var command = new CommandBuilder(builder.Actions);
 
                 if (vsTools != null)
+                {
                     command.CallBatFile(vsTools.Path);
+                    // `vcvarsall.bat` sets a default Platform environment variable,
+                    // which may not be compatible with the supported platforms of the
+                    // given project/solution. Unsetting it means that the default platform
+                    // of the project/solution is used instead.
+                    command.RunCommand("set Platform=&& type NUL", quoteExe: false);
+                }
 
                 builder.MaybeIndex(command, MsBuild);
                 command.QuoteArgument(projectOrSolution.FullPath);