CodeQL frequently runs out of memory

[vadi2]

See https://github.com/Mudlet/Mudlet/runs/2545548490?check_suite_focus=true. This only started happening recently.

tarting evaluation of codeql-cpp/Security/CWE/CWE-676/DangerousUseOfCin.ql.
  
  <--- Last few GCs --->
  FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
  
  [15072:0x4152290]   358171 ms: Mark-sweep 2044.9 (2050.5) -> 2044.2 (2050.8) MB, 2648.9 / 0.2 ms  (average mu = 0.102, current mu = 0.055) allocation failure scavenge might not succeed
  [15072:0x4152290]   360310 ms: Mark-sweep 2045.0 (2050.8) -> 2044.3 (2050.8) MB, 2136.4 / 0.7 ms  (average mu = 0.058, current mu = 0.001) allocation failure scavenge might not succeed
  
  
  <--- JS stacktrace --->
  
  ==== JS stack trace =========================================
  
      0: ExitFrame [pc: 0x1374fd9]
  Security context: 0x1c8fde0ea671 <JSObject>
      1: assign [0x1c8fde0eaf79](this=0x1c8fde0ea709 <JSFunction Object (sfi = 0x2f98f5fc7d69)>,0x24e7b9366d99 <Object map = 0x26412af40431>,0x24e7b9354089 <Object map = 0x202c0adc4df1>,0x1f85b62e3031 <Object map = 0x4f2c4e158d1>)
      2: loadExtensionMap(aka value) [0x24e7b9354019] [/home/runner/work/_actions/github/codeql-action/v1/node_modules/github-linguist/dis...
  
   1: 0x9da7c0 node::Abort() [/home/runner/runners/2.278.0/externals/node12/bin/node]

[aeisenberg]

This is likely happening because the codeql action is running its lines of code counting concurrently with running the queries. We did this originally to save time, but it's looking like we can't do both at the same time. I will change the action to run this serially.

[vadi2]

Agree, pity we can't have the optimization.

[aeisenberg]

I can reproduce this counting the lines locally. It only happens after boost is installed. Ie- counting the lines without boost installed completes with no errors. Downloading boost, unzipping, and then counting lines causes OOME.

Going to play around with this some more.

[aeisenberg]

I created a pull request that should allow your code scanning to work again. The change explicitly ignores the 3rdparty directory. It's not ideal since we should not be running out of memory here. This does not require the workflow to run in serial.

[vadi2]

If it makes CodeQL to run quicker - to be honest an even better solution, I don't mind specifying it by hand. Thanks for checking this out so quickly!

[aeisenberg]

Closing this issue in favour of github/codeql-action#498 where we will do more work.