Handle null source sections in DSL intepreter

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/code/CodeBuiltins.java

@@ -490,14 +490,16 @@ Object positions(PCode self) {
                             continue;
                         }
                         SourceSection section = rootNode.getSourceSectionForLocation(instruction.getLocation());
-                        lines.add(PFactory.createTuple(language, new int[]{
-                                        section.getStartLine(),
-                                        section.getEndLine(),
-                                        // 1-based inclusive to 0-based inclusive
-                                        section.getStartColumn() - 1,
-                                        // 1-based inclusive to 0-based exclusive (-1 + 1 = 0)
-                                        section.getEndColumn()
-                        }));
+                        if (section != null) {
+                            lines.add(PFactory.createTuple(language, new int[]{
+                                            section.getStartLine(),
+                                            section.getEndLine(),
+                                            // 1-based inclusive to 0-based inclusive
+                                            section.getStartColumn() - 1,
+                                            // 1-based inclusive to 0-based exclusive (-1 + 1 = 0)
+                                            section.getEndColumn()
+                            }));
+                        }
                     }
                 } else {
                     BytecodeCodeUnit bytecodeCo = (BytecodeCodeUnit) co;

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/bytecode_dsl/PBytecodeDSLRootNode.java

@@ -892,7 +892,11 @@ protected Source getSource() {
 
     @TruffleBoundary
     public int bciToLine(int bci, BytecodeNode bytecodeNode) {
-        return getSourceSectionForLocation(bci, bytecodeNode).getStartLine();
+        SourceSection sourceSection = getSourceSectionForLocation(bci, bytecodeNode);
+        if (sourceSection != null) {
+            return sourceSection.getStartLine();
+        }
+        return -1;
     }
 
     @TruffleBoundary