Eclipse CDT is getting stuck Indexing the code

[ks1322]

Describe the bug Eclipse CDT is getting stuck Indexing the code

To Reproduce Steps to reproduce the behavior:

1. Try to index the following code

   int f()
   {
   int x = 0;
   
   return
     x < A<0>::B ?
        x < A<0>::B ?
           x < A<0>::B ?
              x < A<0>::B ? 1 : 0 :
              x < A<0>::B ? 1 : 0 :
           x < A<0>::B ?
              x < A<0>::B ? 1 : 0 :
              x < A<0>::B ? 1 : 0 :
        x < A<0>::B ?
           x < A<0>::B ?
              x < A<0>::B ? 1 : 0 :
              x < A<0>::B ? 1 : 0 :
           x < A<0>::B ?
              x < A<0>::B ?
                 x < A<0>::B ? 1 : 0 :
                 x < A<0>::B ? 1 : 0 :
              x < A<0>::B ?
                 x < A<0>::B ? 1 : 0 :
                 x < A<0>::B ? 1 : 0
   ;
   }

2. Go to Progress tab
3. "Indexing: 0/1 sources, 0 headers: Waiting for exclusive access" message appears in Progress tab
4. Eclipse CDT is getting stuck Indexing the code. Indexing consumes a lot of CPU and never ends.

Expected behavior Indexing process is finished within 1-2 seconds

Version Information (please complete the following information):

• OS and OS Version/extra details: Fedora 39
• Eclipse Version from Help -> About: 2023-09 (4.29.0)
• CDT Version from Help -> About -> Installation Details -> Features tab: 11.3.0.202309051907

[dimitarsh1]

Hi all,

I have a similar issue.

I just download CDT yesterday (different versions; installer and tar.gz) and when I create a managed C++ build it starts indexing and waits for 4-5 minutes (initially I thought it is frozen, so I tried to close it, but after that I let it run and it would finish eventually). But this frozen state happens even if you disable indexing.

It spawns new processes and the CPU utilisation goes up to 100 with little memory being used (the memory is as much as provided in the -Xmx field in the .ini).

I switched from the java which it comes along with to the one I installed (OpenJDK 24) but the same thing happens. The behaviour is reoccuring on my machine (details below) but doesn't happen on another Debian machine with the same kernel.

It spawns many processes, as you can see below and waits for them all to finish.

The behaviour is similar to what is in this post here: http://javamoods.blogspot.com/2009/04/eclipse-user-operation-is-waiting-and.html (and other bug reports but from many years ago).

I attach also the .log from the .metadata folder. [.log](https://github.com/user-attachments/files/16784033/default.log)

System info: $ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux trixie/sid Release: n/a Codename: trixie

$ uname -r 6.6.15-amd64

$ java --version openjdk 24-ea 2025-03-18 OpenJDK Runtime Environment (build 24-ea+10-Debian-2) OpenJDK 64-Bit Server VM (build 24-ea+10-Debian-2, mixed mode, sharing)

I have used all these eclipse versions with the same biheviour:

Any idea? Any more info needed from my side?

Thanks in advance.

[ks1322]

@dimitarsh1, what code are you trying to index? In my case I do not disable indexing and it works in general for large codebase. Only mentioned piece of code in https://github.com/eclipse-cdt/cdt/issues/892#issue-2484855081 makes indexing to stuck.

[dimitarsh1]

When I create a new project, when I build a project, when I run a project. Basically it always creates many new processes which cause the main one to halt/wait.

Perhaps my issue is unrelated to yours and I should open a new issue.

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---

From: ks1322 @.> Sent: Wednesday, August 28, 2024 8:26:41 PM To: eclipse-cdt/cdt @.> Cc: Dimitar Shterionov @.>; Mention @.> Subject: Re: [eclipse-cdt/cdt] Eclipse CDT is getting stuck Indexing the code (Issue #892)

@dimitarsh1https://github.com/dimitarsh1, what code are you trying to index? In my case I do not disable indexing and it works in general for large codebase. Only mentioned piece of code in #892 (comment)https://github.com/eclipse-cdt/cdt/issues/892#issue-2484855081 makes indexing to stuck.

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[jld01]

Related to Bugzilla 363609.

See the code comments in the TemplateIdStrategy class.

I can avoid the endless loop reported above by disabling this optimization in the source code.

[ks1322]

I don't think an endless loop is invoked in Eclipse. Looks like some exponential algorithm is invoked. If I remove several instances of conditional operator then no stuck is observed, Indexing process finishes.

[gvl2023]

I've seen indexer getting stuck with increasing heap usage and an eventual OOM error. I had to exclude folders containing sources that the indexer chokes on. Hope I'm wrong but with the recently introduced language-server based editor the chances of the indexer getting patched are fairly slim.