[GR-25628] Translate regexp SyntaxExceptions in visitMatch2Node

PullRequest: truffleruby/2825

Author: bjfish

src/main/java/org/truffleruby/core/regexp/ClassicRegexp.java

@@ -101,12 +101,16 @@ public static Regex makeRegexp(RubyContext context, RubyDeferredWarnings rubyDef
                             ? new RegexWarnCallback(context)
                             : new RegexWarnDeferredCallback(rubyDeferredWarnings));
         } catch (Exception e) {
-            String errorMessage = BacktraceFormatter.formatJavaThrowableMessage(e) + ": /" +
-                    RopeOperations.decodeRope(source) + "/";
+            String errorMessage = getRegexErrorMessage(source, e, options);
             throw new DeferredRaiseException(c -> c.getCoreExceptions().regexpError(errorMessage, currentNode));
         }
     }
 
+    public static String getRegexErrorMessage(Rope source, Exception e, RegexpOptions options) {
+        return BacktraceFormatter.formatJavaThrowableMessage(e) + ": /" +
+                RopeOperations.decodeRope(source) + "/" + options.toOptionsString();
+    }
+
     private static Regex getRegexpFromCache(RubyContext context, RopeBuilder bytes, RubyEncoding encoding,
             RegexpOptions options, Rope source) throws DeferredRaiseException {
         if (context == null) {

src/main/java/org/truffleruby/core/regexp/RegexpOptions.java

@@ -202,6 +202,20 @@ public RegexpOptions withoutOnce() {
         return options;
     }
 
+    public String toOptionsString() {
+        StringBuilder flags = new StringBuilder(3);
+        if (isMultiline()) {
+            flags.append('m');
+        }
+        if (isIgnorecase()) {
+            flags.append('i');
+        }
+        if (isExtended()) {
+            flags.append('x');
+        }
+        return flags.toString();
+    }
+
     @Override
     public int hashCode() {
         int hash = 7;

src/main/java/org/truffleruby/parser/BodyTranslator.java

@@ -48,6 +48,7 @@
 import org.truffleruby.core.module.ModuleNodesFactory;
 import org.truffleruby.core.numeric.BignumOperations;
 import org.truffleruby.core.range.RangeNodesFactory;
+import org.truffleruby.core.regexp.ClassicRegexp;
 import org.truffleruby.core.regexp.EncodingCache;
 import org.truffleruby.core.regexp.InterpolatedRegexpNode;
 import org.truffleruby.core.regexp.MatchDataNodes.GetIndexNode;
@@ -2114,14 +2115,22 @@ public RubyNode visitMatch2Node(Match2ParseNode node) {
         if (node.getReceiverNode() instanceof RegexpParseNode) {
             final RegexpParseNode regexpNode = (RegexpParseNode) node.getReceiverNode();
             final byte[] bytes = regexpNode.getValue().getBytes();
-            final Regex regex = new Regex(
-                    bytes,
-                    0,
-                    bytes.length,
-                    regexpNode.getOptions().toOptions(),
-                    regexpNode.getEncoding(),
-                    Syntax.RUBY,
-                    new RegexWarnDeferredCallback(rubyWarnings));
+            final Regex regex;
+            try {
+                regex = new Regex(
+                        bytes,
+                        0,
+                        bytes.length,
+                        regexpNode.getOptions().toOptions(),
+                        regexpNode.getEncoding(),
+                        Syntax.RUBY,
+                        new RegexWarnDeferredCallback(rubyWarnings));
+            } catch (Exception e) {
+                String errorMessage = ClassicRegexp
+                        .getRegexErrorMessage(regexpNode.getValue(), e, regexpNode.getOptions());
+                final RubyContext context = RubyLanguage.getCurrentContext();
+                throw new RaiseException(context, context.getCoreExceptions().regexpError(errorMessage, currentNode));
+            }
             final int numberOfNames = regex.numberOfNames();
 
             if (numberOfNames > 0) {