Enable WarnExperimentalFeatures by default for embedding

Author: msimacek

CHANGELOG.md

@@ -7,7 +7,7 @@ language runtime. The main focus is on user-observable behavior of the engine.
 * Updated developer metadata of Maven artifacts.
 
 ## Version 24.1.0
-* GraalPy is now considered stable for pure Python workloads. While many workloads involving native extension modules work, we continue to consider them experimental. You can use the command-line option `--python.WarnExperimentalFeatures` to enable warnings for such modules at runtime. In Java embeddings, set the context option `python.WarnExperimentalFeatures` to true.
+* GraalPy is now considered stable for pure Python workloads. While many workloads involving native extension modules work, we continue to consider them experimental. You can use the command-line option `--python.WarnExperimentalFeatures` to enable warnings for such modules at runtime. In Java embeddings the warnings are enabled by default and you can suppress them by setting the context option 'python.WarnExperimentalFeatures' to 'false'.
 * Update to Python 3.11.7
 * We now provide intrinsified `_pickle` module also in the community version.
 * `polyglot.eval` now raises more meaningful exceptions. Unavaliable languages raise `ValueError`. Exceptions from the polyglot language are raised directly as interop objects (typed as `polyglot.ForeignException`). The shortcut for executing python files without specifying language has been removed, use regular `eval` for executing Python code.

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

@@ -791,6 +791,10 @@ protected void launch(Builder contextBuilder) {
             contextBuilder.option("python.PosixModuleBackend", "java");
         }
 
+        if (!hasContextOptionSetViaCommandLine("WarnExperimentalFeatures")) {
+            contextBuilder.option("python.WarnExperimentalFeatures", "false");
+        }
+
         if (multiContext) {
             contextBuilder.engine(Engine.newBuilder().allowExperimentalOptions(true).options(enginePolyglotOptions).build());
         }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/common/CExtContext.java

@@ -306,7 +306,13 @@ public static Object loadCExtModule(Node location, PythonContext context, Module
                     throws IOException, ApiInitException, ImportException {
 
         if (context.getOption(PythonOptions.WarnExperimentalFeatures) && !C_EXT_SUPPORTED_LIST.contains(spec.name.toJavaStringUncached())) {
-            getLogger().warning(() -> "Loading C extension module %s from '%s'. Support for the Python C API is considered experimental.".formatted(spec.name, spec.path));
+            getLogger().warning(() -> {
+                String message = "Loading C extension module %s from '%s'. Support for the Python C API is considered experimental.";
+                if (!context.getOption(PythonOptions.RunViaLauncher)) {
+                    message += " You can suppress this warning by setting the context option 'python.WarnExperimentalFeatures' to 'false'";
+                }
+                return message.formatted(spec.name, spec.path);
+            });
         }
 
         // we always need to load the CPython C API

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

@@ -389,7 +389,7 @@ private PythonOptions() {
     public static final OptionKey<Boolean> UseNativePrimitiveStorageStrategy = new OptionKey<>(false);
 
     @Option(category = OptionCategory.EXPERT, usageSyntax = "true|false", help = "Print warnings when using experimental features at runtime.", stability = OptionStability.STABLE) //
-    public static final OptionKey<Boolean> WarnExperimentalFeatures = new OptionKey<>(false);
+    public static final OptionKey<Boolean> WarnExperimentalFeatures = new OptionKey<>(true);
 
     public static final OptionDescriptors DESCRIPTORS = new PythonOptionsOptionDescriptors();