Unbalanced eval brackets causes TF parser loop

Describe the bug From this (link 1, link 2) slack conversation, a malformed eval statement with mismatched brackets can cause a loop in the TF parser. Example statement (note missing closing bracket):

s3_access_logs_prefix = "${replace(var.cdn_logging_prefix, "cdn", "s3")/${var.bucket_name}"

It is currently unknown if it is an infinite loop, but it’s at least very slow.

To Reproduce I have reproduced with this parse scenario: main.tf:

locals {
  # This is intentionally missing the closing bracket
  s3_access_logs_prefix = "${replace(var.cdn_logging_prefix, "cdn", "s3")/${var.bucket_name}"
}

Expected behavior expected.json:

{
  "main.tf": {
    "locals": [
      {
        "s3_access_logs_prefix": ["${replace(var.cdn_logging_prefix, 'cdn', 's3')/${var.bucket_name}"]
      }
    ]
  }
}

I wouldn’t expect extra looping in the parser.

[arielkru]

@robeden Good idea, I’m not sure about it but I’ll check that out

[metahertz]

🤘 Rock on! Thanks Rob, know you’ve been speaking with Barak+Ariel on the issue.

Adding a bit of context for other watchers on the issue: Parser in use by checkov is here: https://github.com/bridgecrewio/python-hcl2 Assigning @arielkru and work-in-progress