[all-commits] [llvm/llvm-project] 2dca0b: [AsmParser][SystemZ][z/OS] Fix hanging scenario in...

[Anirudh Prasad via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2dca0b5a1ce431692136b293fd5f9ecadea31750
      https://github.com/llvm/llvm-project/commit/2dca0b5a1ce431692136b293fd5f9ecadea31750
  Author: Anirudh Prasad <anirudh_prasad at hotmail.com>
  Date:   2021-06-28 (Mon, 28 Jun 2021)

  Changed paths:
    M llvm/lib/MC/MCParser/AsmParser.cpp

  Log Message:
  -----------
  [AsmParser][SystemZ][z/OS] Fix hanging scenario in HLASMAsmParser class

- In the caller of the overridden `parseStatement` function (i.e. the `AsmParser::Run()`) in the case of an error **and** if we're not at the start of the statement, we "eat" up until the end of the current statement, so we don't have to process it again.
- However, in the HLASMAsmParser class what's happening is that, if an error occurs at the very start of the statement (for example, you invoke the HLASMAsmParser to parse a gnu directive), we will error out, but we never really progress in terms of the next token in the statement to parse. We simply keep looping processing the same error over and over again (partly because we're at the start of the statement)
- To remedy this, when the `parseAsHLASMLabel` function fails, before returning, we "eat" until the end of the statement function, so we don't process it anymore.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D104869