Implement environment variable passing for Process on Win32. Closes #790

. Closes #792

sdk/os/native/ProcessWin32.ooc

@@ -76,6 +76,8 @@ ProcessWin32: class extends Process {
             si flags |= StartFlags UseStdHandles
         }
 
+        envString := buildEnvironment()
+
         // Reference: http://msdn.microsoft.com/en-us/library/ms682512%28VS.85%29.aspx
         // Start the child process.
         if(!CreateProcess(
@@ -85,7 +87,7 @@ ProcessWin32: class extends Process {
             null,        // Thread handle not inheritable
             true,        // Set handle inheritance to true
             0,           // No creation flags
-            null,        // Use parent's environment block
+            envString,   // Use parent's environment block
             cwd ? cwd toCString() : null, // Use custom cwd if we have one
             si&,         // Pointer to STARTUPINFO structure
             pi&          // Pointer to PROCESS_INFORMATION structure
@@ -114,6 +116,40 @@ ProcessWin32: class extends Process {
         return pi pid
     }
 
+    buildEnvironment: func -> Char* {
+        if (env == null) {
+            return null
+        }
+
+        envLength := 1
+        env each(|k, v|
+            envLength += k size
+            envLength += v size
+            envLength += 2 // one for the =, one for the \0
+        )
+
+        envString := gc_malloc(envLength) as Char*
+        index := 0
+        for (k in env getKeys()) {
+            v := env get(k)
+
+            memcpy(envString + index, k toCString(), k size)
+            index += k size
+
+            envString[index] = '='
+            index += 1
+
+            memcpy(envString + index, v toCString(), v size)
+            index += v size
+
+            envString[index] = '\0'
+            index += 1
+        }
+
+        envString[index] = '\0'
+        envString
+    }
+
     terminate: func {
         // TODO!
         "please implement me! ProcessWin32 terminate" println()

test/sdk/os/processenv.ooc

@@ -1,12 +1,23 @@
 import os/Process, structs/HashMap
 
-p := Process new(["bash", "-c", "echo $MYVAR"])
+main: func {
+    env := HashMap<String, String> new()
+    env put("MYVAR", "42")
 
-env := HashMap<String, String> new()
-env put("MYVAR", "42")
-p setEnv(env)
+    command := ["bash", "-c", "echo $MYVAR"]
+    version (windows) {
+        command = ["cmd", "/c", "echo %MYVAR%"]
+    }
 
-p execute()
-output := p getOutput()
+    p := Process new(command)
+    p setEnv(env)
+    p execute()
+    output := p getOutput()
+    output = output trim()
+    if (output != "42") {
+        "Fail! expected output = 42, but got #{output}" println()
+        exit(1)
+    }
 
-"output = %s" printfln(output)
+    "Pass" println()
+}