extend resources junit test to check we can use resources in embedding with IO disallowed

Author: timfel

graalpython/com.oracle.graal.python.test/src/com/oracle/graal/python/test/advance/ResourcesTest.java

@@ -43,7 +43,9 @@
 import static org.junit.Assert.assertTrue;
 
 import java.io.File;
+
 import org.graalvm.polyglot.Context;
+import org.graalvm.polyglot.io.IOAccess;
 import org.junit.Test;
 
 public class ResourcesTest {
@@ -59,4 +61,12 @@ public void testResourcesAsHome() {
             assertTrue(foundHome, !foundHome.contains("graalpython"));
         }
     }
+
+    @Test
+    public void testResourcesAlwaysAllowReading() {
+        try (Context context = Context.newBuilder("python").allowIO(IOAccess.NONE).option("python.PythonHome", "/path/that/does/not/exist").build()) {
+            String foundHome = context.eval("python", "import email; email.__spec__.origin").asString();
+            assertTrue(foundHome, foundHome.contains("python" + File.separator + "python-home"));
+        }
+    }
 }

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

@@ -1665,6 +1665,7 @@ private void initializePosixSupport() {
     }
 
     private TruffleString langHome, sysPrefix, basePrefix, coreHome, capiHome, jniHome, stdLibHome;
+    private TruffleFile homeResourcesFile;
 
     public void initializeHomeAndPrefixPaths(Env newEnv, String languageHome) {
         if (ImageInfo.inImageBuildtimeCode()) {
@@ -1704,7 +1705,8 @@ public void initializeHomeAndPrefixPaths(Env newEnv, String languageHome) {
                         () -> {
                             if (PythonLanguage.PYTHON_RESOURCE_CLASS != null && !ImageInfo.inImageCode()) {
                                 try {
-                                    return newEnv.getInternalResource(PythonLanguage.PYTHON_RESOURCE_CLASS).getAbsoluteFile();
+                                    homeResourcesFile = newEnv.getInternalResource(PythonLanguage.PYTHON_RESOURCE_CLASS).getAbsoluteFile();
+                                    return homeResourcesFile;
                                 } catch (IOException e) {
                                     // fall through
                                 }
@@ -2274,6 +2276,15 @@ void releaseGil() {
      */
     @TruffleBoundary
     public TruffleFile getPublicTruffleFileRelaxed(TruffleString path, TruffleString... allowedSuffixes) {
+        if (homeResourcesFile != null && !env.isFileIOAllowed()) {
+            // XXX: Workaround for Truffle resources not being considered internal truffle files
+            String jlPath = path.toJavaStringUncached();
+            String jlHome = langHome.toJavaStringUncached();
+            if (jlPath.startsWith(jlHome)) {
+                String homeRelativePath = jlPath.substring(jlHome.length() + 1);
+                return homeResourcesFile.resolve(homeRelativePath);
+            }
+        }
         TruffleFile f = env.getInternalTruffleFile(path.toJavaStringUncached());
         // 'isDirectory' does deliberately not follow symlinks because otherwise this could allow to
         // escape the language home directory.

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

@@ -139,7 +139,7 @@ private PythonOptions() {
     }
 
     @Option(category = OptionCategory.EXPERT, help = "Set the home of Python. Equivalent of GRAAL_PYTHONHOME env variable. " +
-                    "Determines default values for the CoreHome, StdLibHome, SysBasePrefix, SysPrefix.", usageSyntax = "<path>", stability = OptionStability.EXPERIMENTAL) //
+                    "Determines default values for the CoreHome, StdLibHome, SysBasePrefix, SysPrefix.", usageSyntax = "<path>", stability = OptionStability.STABLE) //
     public static final OptionKey<String> PythonHome = new OptionKey<>("");
 
     @Option(category = OptionCategory.USER, help = "Set the location of sys.prefix. Overrides any environment variables or Java options.", usageSyntax = "<path>", stability = OptionStability.STABLE) //