VerifyError with String Templates

[hjohn]

The following code:

package hs.mediasystem.db.base;

import java.lang.StringTemplate.Processor;
import java.util.Map;

public class VerifyBug {

  public static void main(String[] args) throws Exception {
    Map<String, String> stuff = Map.of("a", "b");
    Transaction tx = new Transaction();

    for(Map.Entry<String, String> entry : stuff.entrySet()) {
      String name = entry.getKey();

      String s = tx."""
        INSERT INTO settings (a, b) VALUES (\{name}, \{entry.getValue()})
      """;
    }
  }

  static class Transaction implements Processor<String, Exception> {
    @Override
    public String process(StringTemplate stringTemplate) throws Exception {
      return null;
    }
  }
}

When run will produce a VerifyError:

Error: Unable to initialize main class hs.mediasystem.db.base.VerifyBug
Caused by: java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    hs/mediasystem/db/base/VerifyBug.main([Ljava/lang/String;)V @63: invokedynamic
  Reason:
    Type 'java/lang/Object' (current frame, stack[2]) is not assignable to 'java/lang/String'
  Current Frame:
    bci: @63
    flags: { }
    locals: { '[Ljava/lang/String;', 'java/util/Map', 'hs/mediasystem/db/base/VerifyBug$Transaction', 'java/util/Map$Entry', 'java/util/Iterator', 'java/lang/String' }
    stack: { 'hs/mediasystem/db/base/VerifyBug$Transaction', 'java/lang/String', 'java/lang/Object' }
  Bytecode:
    0000000: 1213 1215 b800 174c bb00 1d59 b700 1f4d
    0000010: 2bb9 0020 0100 b900 2401 003a 04a7 002f
    0000020: 1904 b900 2a01 00c0 0030 4e2d b900 3201
    0000030: 00c0 0035 3a05 2c19 052d b900 3701 00ba
    0000040: 003a 0000 b600 3ec0 0035 3a06 1904 b900
    0000050: 4101 009a ffcd b1                      
  Stackmap Table:
    full_frame(@32,{Object[#83],Object[#24],Object[#29],Top,Object[#43]},{})
    same_frame(@76)

The problem can be fixed by first extracting entry.getValue() into a String like:

    for(Map.Entry<String, String> entry : stuff.entrySet()) {
      String name = entry.getKey();
      String value = entry.getValue();

      String s = tx."""
        INSERT INTO settings (a, b) VALUES (\{name}, \{value})
      """;
    }

[srikanth-sankaran]

@jarthana - if you are unable to get to this in time for 4.32 M1, let me know a couple weeks in advance - TIA

[iloveeclipse]

@srikanth-sankaran : is this related to / covered by #2171 ?

[srikanth-sankaran]

@srikanth-sankaran : is this related to / covered by #2171 ?

It is not related to it. But now that I looked at the code generated, I know what the problem is that causes the verify error. We are missing a generic cast I think. I'll follow up.