Add --backtraces-to-native to show a backtrace on ValueWrapper#toNative

Author: eregon

src/main/java/org/truffleruby/cext/ValueWrapperManager.java

@@ -315,7 +315,7 @@ protected long allocateSharedHandleOnKnownThread(ValueWrapper wrapper) {
                     true);
         }
 
-        protected static long allocateHandle(ValueWrapper wrapper, RubyContext context, RubyLanguage language,
+        protected long allocateHandle(ValueWrapper wrapper, RubyContext context, RubyLanguage language,
                 HandleBlockHolder holder, boolean shared) {
             HandleBlock block;
             if (shared) {
@@ -328,6 +328,10 @@ protected static long allocateHandle(ValueWrapper wrapper, RubyContext context,
                 context.getValueWrapperManager().recordHandleAllocation();
             }
 
+            if (context.getOptions().BACKTRACE_ON_TO_NATIVE) {
+                context.getDefaultBacktraceFormatter().printBacktraceOnEnvStderr("ValueWrapper#toNative: ", getNode());
+            }
+
             if (block == null || block.isFull()) {
                 if (block != null) {
                     context.getMarkingService().queueForMarking(block);

src/main/java/org/truffleruby/options/Options.java

@@ -166,6 +166,8 @@ public class Options {
     public final boolean CEXTS_TO_NATIVE_STATS;
     /** --cexts-to-native-count=CEXTS_TO_NATIVE_STATS */
     public final boolean CEXTS_TO_NATIVE_COUNT;
+    /** --backtraces-to-native=false */
+    public final boolean BACKTRACE_ON_TO_NATIVE;
     /** --basic-ops-log-rewrite=false */
     public final boolean BASICOPS_LOG_REWRITE;
     /** --array-small=3 */
@@ -279,6 +281,7 @@ public Options(Env env, OptionValues options, LanguageOptions languageOptions) {
         PRINT_INTERNED_TSTRING_STATS = options.get(OptionsCatalog.PRINT_INTERNED_TSTRING_STATS_KEY);
         CEXTS_TO_NATIVE_STATS = options.get(OptionsCatalog.CEXTS_TO_NATIVE_STATS_KEY);
         CEXTS_TO_NATIVE_COUNT = options.hasBeenSet(OptionsCatalog.CEXTS_TO_NATIVE_COUNT_KEY) ? options.get(OptionsCatalog.CEXTS_TO_NATIVE_COUNT_KEY) : CEXTS_TO_NATIVE_STATS;
+        BACKTRACE_ON_TO_NATIVE = options.get(OptionsCatalog.BACKTRACE_ON_TO_NATIVE_KEY);
         BASICOPS_LOG_REWRITE = options.get(OptionsCatalog.BASICOPS_LOG_REWRITE_KEY);
         ARRAY_SMALL = options.get(OptionsCatalog.ARRAY_SMALL_KEY);
         CEXTS_MARKING_CACHE = options.get(OptionsCatalog.CEXTS_MARKING_CACHE_KEY);
@@ -445,6 +448,8 @@ public Object fromDescriptor(OptionDescriptor descriptor) {
                 return CEXTS_TO_NATIVE_STATS;
             case "ruby.cexts-to-native-count":
                 return CEXTS_TO_NATIVE_COUNT;
+            case "ruby.backtraces-to-native":
+                return BACKTRACE_ON_TO_NATIVE;
             case "ruby.basic-ops-log-rewrite":
                 return BASICOPS_LOG_REWRITE;
             case "ruby.array-small":

src/options.yml

@@ -173,6 +173,7 @@ INTERNAL: # Options for debugging the TruffleRuby implementation
     PRINT_INTERNED_TSTRING_STATS: [print-interned-tstring-stats, boolean, false, Print interned tstring stats at application exit]
     CEXTS_TO_NATIVE_STATS: [cexts-to-native-stats, boolean, false, Track the number of conversions of VALUEs to native and print the stats at application exit]
     CEXTS_TO_NATIVE_COUNT: [cexts-to-native-count, boolean, CEXTS_TO_NATIVE_STATS, Track the number of conversions of VALUEs to native]
+    BACKTRACE_ON_TO_NATIVE: [backtraces-to-native, boolean, false, Show a backtrace when a ValueWrapper handle is created for a Ruby object]
 
     # Options to debug the implementation
     LAZY_BUILTINS: [lazy-builtins, boolean, LAZY_CALLTARGETS, Load builtin classes (core methods & primitives) lazily on first use]

src/shared/java/org/truffleruby/shared/options/OptionsCatalog.java

@@ -103,6 +103,7 @@ public class OptionsCatalog {
     public static final OptionKey<Boolean> PRINT_INTERNED_TSTRING_STATS_KEY = new OptionKey<>(false);
     public static final OptionKey<Boolean> CEXTS_TO_NATIVE_STATS_KEY = new OptionKey<>(false);
     public static final OptionKey<Boolean> CEXTS_TO_NATIVE_COUNT_KEY = new OptionKey<>(CEXTS_TO_NATIVE_STATS_KEY.getDefaultValue());
+    public static final OptionKey<Boolean> BACKTRACE_ON_TO_NATIVE_KEY = new OptionKey<>(false);
     public static final OptionKey<Boolean> LAZY_BUILTINS_KEY = new OptionKey<>(LAZY_CALLTARGETS_KEY.getDefaultValue());
     public static final OptionKey<Boolean> LAZY_TRANSLATION_CORE_KEY = new OptionKey<>(LAZY_CALLTARGETS_KEY.getDefaultValue());
     public static final OptionKey<Boolean> CHAOS_DATA_KEY = new OptionKey<>(false);
@@ -827,6 +828,14 @@ public class OptionsCatalog {
             .usageSyntax("")
             .build();
 
+    public static final OptionDescriptor BACKTRACE_ON_TO_NATIVE = OptionDescriptor
+            .newBuilder(BACKTRACE_ON_TO_NATIVE_KEY, "ruby.backtraces-to-native")
+            .help("Show a backtrace when a ValueWrapper handle is created for a Ruby object")
+            .category(OptionCategory.INTERNAL)
+            .stability(OptionStability.EXPERIMENTAL)
+            .usageSyntax("")
+            .build();
+
     public static final OptionDescriptor LAZY_BUILTINS = OptionDescriptor
             .newBuilder(LAZY_BUILTINS_KEY, "ruby.lazy-builtins")
             .help("Load builtin classes (core methods & primitives) lazily on first use")
@@ -1467,6 +1476,8 @@ public static OptionDescriptor fromName(String name) {
                 return CEXTS_TO_NATIVE_STATS;
             case "ruby.cexts-to-native-count":
                 return CEXTS_TO_NATIVE_COUNT;
+            case "ruby.backtraces-to-native":
+                return BACKTRACE_ON_TO_NATIVE;
             case "ruby.lazy-builtins":
                 return LAZY_BUILTINS;
             case "ruby.lazy-translation-core":
@@ -1675,6 +1686,7 @@ public static OptionDescriptor[] allDescriptors() {
             PRINT_INTERNED_TSTRING_STATS,
             CEXTS_TO_NATIVE_STATS,
             CEXTS_TO_NATIVE_COUNT,
+            BACKTRACE_ON_TO_NATIVE,
             LAZY_BUILTINS,
             LAZY_TRANSLATION_CORE,
             CHAOS_DATA,