Set 'sys.executable' on startup for AOT.

(cherry picked from commit ebf2d3c)

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java

@@ -102,6 +102,7 @@ protected void finalizeContext(PythonContext context) {
 
     @Override
     protected boolean patchContext(PythonContext context, Env newEnv) {
+        ensureSysExecutable(context);
         ensureHomeInOptions(newEnv);
         if (!optionsAllowPreInitializedContext(context, newEnv)) {
             // Incompatible options - cannot use pre-initialized context
@@ -114,6 +115,11 @@ protected boolean patchContext(PythonContext context, Env newEnv) {
         return true;
     }
 
+    private static void ensureSysExecutable(PythonContext context) {
+        PythonModule sys = context.getCore().lookupBuiltinModule("sys");
+        sys.setAttribute("executable", Compiler.command(new Object[]{"com.oracle.svm.core.posix.GetExecutableName"}));
+    }
+
     private static boolean optionsAllowPreInitializedContext(PythonContext context, Env newEnv) {
         // Verify that the option for using a shared core is the same as
         // at image building time

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java

@@ -100,7 +100,9 @@ public void initialize(PythonCore core) {
         builtinConstants.put("copyright", LICENSE);
         builtinConstants.put("dont_write_bytecode", true);
         if (TruffleOptions.AOT) {
-            builtinConstants.put("executable", Compiler.command(new Object[]{"com.oracle.svm.core.posix.GetExecutableName"}));
+            // cannot set the path at this time since the binary is not yet known; will be patched
+            // in the context
+            builtinConstants.put("executable", PNone.NONE);
         } else {
             StringBuilder sb = new StringBuilder();
             sb.append(System.getProperty("java.home")).append(PythonCore.FILE_SEPARATOR).append("bin").append(PythonCore.FILE_SEPARATOR).append("java ");