[GR-8143] Support PYTHONPATH environment variable for prefixing sys.path

Author: timfel

graalpython/com.oracle.graal.python.shell/src/com/oracle/graal/python/shell/GraalPythonMain.java

@@ -172,6 +172,11 @@ protected void launch(Builder contextBuilder) {
             contextBuilder.option("log.python.level", "FINE");
         }
 
+        String pythonpath = System.getenv("PYTHONPATH");
+        if (pythonpath != null) {
+            contextBuilder.option("python.PythonPath", pythonpath);
+        }
+
         ConsoleHandler consoleHandler = createConsoleHandler(System.in, System.out);
         contextBuilder.arguments(getLanguageId(), programArgs.toArray(new String[0])).in(consoleHandler.createInputStream());
 

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/Python3Core.java

@@ -130,6 +130,7 @@
 import com.oracle.graal.python.builtins.objects.type.TypeBuiltins;
 import com.oracle.graal.python.runtime.PythonContext;
 import com.oracle.graal.python.runtime.PythonCore;
+import com.oracle.graal.python.runtime.PythonOptions;
 import com.oracle.graal.python.runtime.PythonParser;
 import com.oracle.graal.python.runtime.exception.PException;
 import com.oracle.graal.python.runtime.exception.PythonErrorType;
@@ -364,19 +365,23 @@ public PythonModule initializeSysModule() {
 
     private void initializeSysPath(PythonModule sys, String[] args) {
         Env env = getContext().getEnv();
-        Object[] path = new Object[]{
-                        getScriptPath(env, args),
-                        PythonCore.getStdlibHome(env),
-                        PythonCore.getCoreHome(env) + PythonCore.FILE_SEPARATOR + "modules"};
+        String option = PythonOptions.getOption(getContext(), PythonOptions.PythonPath);
+        Object[] path;
+        int pathIdx = 0;
+        if (option.length() > 0) {
+            String[] split = option.split(PythonCore.PATH_SEPARATOR);
+            path = new Object[split.length + 3];
+            System.arraycopy(split, 0, path, 0, split.length);
+            pathIdx = split.length;
+        } else {
+            path = new Object[3];
+        }
+        path[pathIdx] = getScriptPath(env, args);
+        path[pathIdx + 1] = PythonCore.getStdlibHome(env);
+        path[pathIdx + 2] = PythonCore.getCoreHome(env) + PythonCore.FILE_SEPARATOR + "modules";
         PList sysPaths = factory().createList(path);
         sys.setAttribute("path", sysPaths);
         // sysPaths.append(getPythonLibraryExtrasPath());
-        String pythonPath = System.getenv("PYTHONPATH");
-        if (pythonPath != null) {
-            for (String s : pythonPath.split(PythonCore.PATH_SEPARATOR)) {
-                sysPaths.append(s);
-            }
-        }
     }
 
     private static String getScriptPath(Env env, String[] args) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonOptions.java

@@ -85,6 +85,9 @@ private PythonOptions() {
     @Option(category = OptionCategory.USER, help = "") //
     public static final OptionKey<Boolean> InspectFlag = new OptionKey<>(false);
 
+    @Option(category = OptionCategory.USER, help = "") //
+    public static final OptionKey<String> PythonPath = new OptionKey<>("");
+
     @Option(category = OptionCategory.USER, help = "Remove assert statements and any code conditional on the value of __debug__.") //
     public static final OptionKey<Boolean> PythonOptimizeFlag = new OptionKey<>(false);