Vscode-cpptools: Infinite loop in the Intellisense process

[ogrisel]

Steps to reproduce:

• Install vs code and the official C/C++ extension by Microsoft
• git clone https://github.com/python/cpython
• cd cpython
• code .
• ctrl-p to open "Modules/_pickle.c"

Problem

The following process runs in the background with 100% CPU usage:

/home/testuser/.vscode/extensions/ms-vscode.cpptools-0.14.3/bin/Microsoft.VSCode.CPP.IntelliSense.Msvc.linux

There is also the following process:

/home/testuser/.vscode/extensions/ms-vscode.cpptools-0.14.3/bin/Microsoft.VSCode.CPP.Extension.linux

All those processes stay alive after exiting VS Code. I have to kill Microsoft.VSCode.CPP.IntelliSense.Msvc.linux manually to terminate it. When I do not kill it seems to run for ever (I waited at least 20 min) and it was still running with 100% CPU.

Environment:

• Ubuntu Linux 16.04
• VS Code 1.18.1
• vscode-cpp-tools 0.14.2

I created a new testuser account and installed no other extension besides vscode-cpp-tools. My settings.json is empty. I tried to use:

"C_Cpp.intelliSenseEngine": "Default"

instead but does not seem to fix the problem.

Here is the output of the log of the C/C++ extension:

IntelliSense Engine = Default.
The extension will use the Tag Parser for IntelliSense when #includes don't resolve.
Autocomplete is enabled.
Error squiggles are enabled.
File exclude: **/.git
File exclude: **/.svn
File exclude: **/.hg
File exclude: **/CVS
File exclude: **/.DS_Store
File exclude: **/.vscode
Search exclude: **/node_modules
Search exclude: **/bower_components
Search exclude: **/.vscode
Code browsing service initialized
  Folder: /usr/lib/gcc/x86_64-linux-gnu/5/include/ will be indexed
  Folder: /usr/local/include/ will be indexed
  Folder: /usr/lib/gcc/x86_64-linux-gnu/5/include-fixed/ will be indexed
  Folder: /usr/include/ will be indexed
  Folder: /home/testuser/code/cpython/ will be indexed
Discovering files...
Checking for syntax errors: file:///home/testuser/code/cpython/Modules/_pickle.c
  Processing folder (recursive): /usr/lib/gcc/x86_64-linux-gnu/5/include/
  Processing folder (recursive): /usr/local/include/
  Processing folder (recursive): /usr/lib/gcc/x86_64-linux-gnu/5/include-fixed/
  Processing folder (recursive): /usr/include/
  Processing folder (recursive): /home/testuser/code/cpython/
  Indexing: 8689 file(s) processed
  Indexing: 0 file(s) removed from database
Done discovering files.
Parsing open files...
Done parsing open files.
Checking for edits and parsing remaining files...
  Processing folder (recursive): /home/testuser/code/cpython/
  Parsing: 4283 files(s) processed
Done parsing remaining files.

[bobbrow]

Thank you for the report. I am able to duplicate this. The IntelliSense process is stuck in an infinite loop and the Extension process is waiting for the IntelliSense process to respond to a shutdown request (which it won't because it's stuck).

That said, I was able to get it working by adding "__GNUC__=5" and "Py_BUILD_CORE" to the "defines" array and "${workspaceRoot}/Include" to the "includePath" in c_cpp_properties.json.

[ogrisel]

I confirm that this workaround works for me as well.

[nico87]

I have the same issue but the suggested workaround did not work.

[0x00deaf]

Well, even if this workaround works for this particular code it does not work for my code project.

Is there any other ways to make intellisense from taking 100% cpu for each opened file (each creates its own thread) that totally hangs the operting system ( 4.15.1-2-ARCH # 1 SMP x86_64 GNU/Linux)

The only solution for me and my team-mates was to do run it with 'nice 20 code'. At least I am able to move my mouse when this happens.

[sean-mcmanus]

@0x00deaf You can set the intelliSenseEngine to "Tag Parser" to disable the IntelliSense process until we can get the infinite processing fixed. 0.16.0 is going to add a compilerPath option and set the compiler defines correctly (and maybe a language version option) which may fix the issue if it's caused by incorrect flags/defines being passed to our parser. But if it's still not fixed, we may need to find a repro or get a call stack.

[Colengms]

This appears to have been addressed. Using the repo steps, I see the IntelliSense process complete an initial pass and settle down quickly. On close, everything shuts down.