Vscode-cpptools: Code folding didn't work as expected in directives and block comment

[LeThiHyVong]

In my code there are many places look like this

#if SOME_CONST_EXP
;//       some code
#else
      // some code
#endif

or

if SOME_CONST_EXP
;//      some code
#endif

or

/*************************************
//
//
//
//
*************************************/

EDIT (@bobbrow): (inserting request for folding on multiple consecutive single-line comments from #1443)

// Comment
// Comment
// Comment
// Comment

The code folding only work correctly between #else and #endif.
From #if to next directive (#else in 1st case or #endif in 2nd case), if all line is started with ';//', the code folding didn't work.
From #endif to next directive, it automatically group the code outside the directive for all time.
The coding folder didn't work for 3rd, too.

System spec:

• Windows 7 SP1 x86
• VSCode 1.7.2
• Plugin 0.9.3

Please correct this.

[sean-mcmanus]

Yes, the code folding is buggy, but it's not a bug with the C/C++ extension. We don't implement any code folding. Can you move this to the vscode team?

[sean-mcmanus]

Actually, it sounds like the folding behavior you are seeing is "by design". The fixing of this is being tracked at https://github.com/Microsoft/vscode/issues/3422 . VS Code implements the folding behavior and there isn't an API yet to allow language-aware folding.

[LeThiHyVong]

According to https://github.com/Microsoft/vscode/issues/3422#event-1582353384, please re-open this issue.
Thanks.

[hoffmael]

This would be a great feature and bug fix to have and essential for the code base I work on which relies on many preprocessor switches to support multiple builds. Diming the inactive code with "C_Cpp.dimInactiveRegions": true is a good first step, but having the ability to collapse and hide the inactive code region altogether is even better.
Eclipse even has the option to collapse inactive regions by default when opening a file by default.

Here's a screenshot from 0.17.4 showing the various issues with folding currently.

[sean-mcmanus]

+1 I hit this issue sometimes with our cross platform code.

[intijk]

C++ folding without supporting this feature basically is useless for cross platform project.

[Flamefire]

@hoffmael Great example why this is required. I ran into pretty much the same thing. What is even worse: It breaks folding of whole namespaces making that completely useless.

Note why this breaks (https://github.com/Microsoft/vscode/issues/57696#issuecomment-418108134):

The folding strategy that you are seeing is based purely on the indentation of lines. A folding region starts when a line has a smaller indent than one or more following lines and ends when there is a line with the same or smaller indent.

[akbyrd]

+1 We definitely need language based folding. The current indentation based implementation is completely unnatural with preprocessor directives and public/private specifiers where a common pattern is to leave them left aligned with no indentation. #endif lines end up as folding nodes and weird, ugly things happen.

A common part of my workflow is to Fold All to get an overview of a file. With indentation based folding this goes to hell.

Here's some example code (note the placement of the folding buttons)

Here's how it actually folds. Not very useful.

Here's how I'd expect it to fold. (Though, honestly I wish the braces and ... got collapsed onto the same line as the function.)

[britalmeida]

Here is an example of how the braces look collapsed on the same line (although they weren't originally):

This is quite important to get the code to fit the screen in the case of big files with many functions.

[akbyrd]

This is a big enough daily nuisance that I started looking at doing it myself, but it looks like most of the language server functionality is bundled up into binaries that get downloaded: Microsoft.VSCode.CPP.Extension.exe & Microsoft.VSCode.CPP.IntelliSense.Msvc.exe.

Any guidance on whether it's possible to get any sort of scope or AST information out of the language server in spite of this?

[sean-mcmanus]

@akbyrd The code for the Microsoft.VSCode.CPP processes is closed source and there's no way to get any AST info (i.e. so you'd need to be a Microsoft employee or contractor). I think we just need to respond to the textDocuent/foldingRange request and run our lexer to compute the ranges. If you can't wait for us, you might be able to write a separate extension that uses an open source lexer to do this.

[akbyrd]

I figured as much. I'll roll with a custom extension for the time being. Do you have any information regarding an ETA for folding support?

[sean-mcmanus]

@akbyrd We don't have any ETA yet, but as soon as we do we'll add this issue to a Milestone with a target month. I would prefer to get this implemented by March, but other issues, such as improving our configuration experience, could get higher priority, and we haven't finished Find All References yet (our top requested feature).

[akbyrd]

@sean-mcmanus With March and April sliding by is there any possibility of nudging this in for the next milestone? Folding is a daily usability issue and language aware folding would be a massive improvement for many people even though they aren't actively complaining about it.

[Flamefire]

+1 for that. What would also be great (as highly related) is some view in which class/namespace/scope you are with the current cursor. This information is probably known, when code folding is implemented and helps for large files...

[sean-mcmanus]

@akbyrd I brought up this issue in our planning meeting, but we still don't have a milestone. The next milestone is probably booked with Find All References, semantic colorization, UI/config work, and performance fixes.

@Flamefire Your issue appears to be tracked by https://github.com/Microsoft/vscode-cpptools/issues/2230 (plus breadcrumbs enabled).

[akbyrd]

If anyone else wants a short term solution I slammed together a folding plugin: https://github.com/akbyrd/vsc-cpp-folding

[Shadowblitz16]

+1 I have OCD and cannot stand to program with visual studio code right now.
code folding should act the same as it does in visual studio 2019 void function() { ... }

[janwilmans]

I don't care who fixes it, could you please resolve it amongst yourselves, fix the relevant issue and close the other. see https://github.com/microsoft/vscode/issues/84977

[aeschli]

@janwilmans the comment

Yes, the code folding is buggy, but it's not a bug with the C/C++ extension. We don't implement any code folding. Can you move this to the vscode team?

was made when there was no API in VSCode for extensions to provide folding regions.

In the meantime there is and as you can see from the followup discussion, the C++ team is aware of the request but has not yet found time to work on it.

[KaeLL]

LMAO 2 weeks away from 3 years since this issue was opened, not counting the fact that you can't have a C/C++ editor without this for any coding other than hello-world level code and still nothing. Amazing.
I'm not blaming the dev's of the cpp extension or anything, just wanted to put it into perspective.

[akbyrd]

I'm not blaming the dev's of the cpp extension

vscode doesn't work with Windows features (Aero Snap). vscode-cpp doesn't work with vscode features (code folding). _Something_ in the process is fundamentally broken when a company can't keep its own products working together smoothly.

[KaeLL]

I'm not blaming the dev's of the cpp extension

vscode doesn't work with Windows features (Aero Snap). vscode-cpp doesn't work with vscode features (code folding). _Something_ in the process is fundamentally broken when a company can't keep its own products working together smoothly.

The aero snap part you can thank Electron for that. It's also the reason why there's no "its own products working together" thing.

[sean-mcmanus]

@KaeLL Yeah, this is currently the 8th top voted feature so hopefully we'll get it implemented some time next year. Last year we implemented Find All Refs and Rename which were the top issues, as well as localization, semantic colorization, doc comments, config UI, hierarchical outline/breadcrumbs, etc., with current work being done on improved multi-root support, a Makefile config provider (with improvements to the CMake Tools extension), improvements to our test coverage, and other bug fixes (i.e. https://github.com/microsoft/vscode-cpptools/milestone/44 ) in preparation for version "1.0".

[intijk]

@KaeLL Yeah, this is currently the 8th top voted feature ...

Hi @sean-mcmanus , could you let me know where to see this rank?

[sean-mcmanus]

@intijk https://github.com/Microsoft/vscode-cpptools/issues?q=is%3Aissue+is%3Aopen+sort%3Areactions-%2B1-desc . I excluded the "debugger" features in the counting.

[yuchongbo]

this issue is opened since 2016 and mentioned by so many people again and again, I am curious why Microsoft Vscode developers have been thinking it not an issue which should be fixed. what's the purpose MS gets the VScode out? can't this be easy for use?

[intijk]

@JYU2018

I kind of think this might be some challenge on the compiler tech that Microsoft people do not have the ability to do it. Anyway if there is a challenge, some idea share the hard point would also welcome.

The real sad thing I've notice about vscode project is, every time new release out, they advertise about how many tickets on the github is resolved, but from my experience, they just diligently close issues instead of really solve them.

[Flamefire]

I actually don't think this is very hard to implement. The ColorRangeProvider (or what it's name was) already has the ranges (or at least some of them) to e.g. shade inactive regions. One could picky-back on that for a quick-fix.

Or with a different approach: Simply detect the preprocessor macros #if, #else, #elif, #endif and return that as ranges. Won't be to performant though depending on how often the ranges are requested.

If someone got some time to do it and open a PR, than maybe it will be accepted. I currently haven't unfortunately. Otherwise there are already plugins out there based on regex to provide ranges. Check them out! :)

[sean-mcmanus]

This just hasn't gotten on our schedule to start working on. Different people have different opinions on what is a priority or not.

[yuchongbo]

Anyway, I do believe this is the BASIC feature which VScode should have at first time the VScode release.

[Flamefire]

Anyway, I do believe this is the BASIC feature which VScode should have at first time the VScode release.

If this was the case: Why are so few people interested in this? The metric for "interested" is the number of :+1: on this issue. There are 33 here and 191 in the top issue, see the comment https://github.com/microsoft/vscode-cpptools/issues/407#issuecomment-560983100

So either convince ~200 people to vote for this, implement it yourself (this is a foss project afterall), use an other extension for code folding (there are some) or wait till this trickles to the top of the priority queue.

[ghost]

I think Atom managed to support this type of folding with the tree-sitter parser, if that's helpful to anyone working on this.

https://blog.atom.io/2018/03/15/atom-1-25.html#improved-syntax-highlighting-and-code-folding

[sean-mcmanus]

@gbhojraj Yeah, there's a thread/issue on VS Code that discusses potentially moving to tree sitter, so then we'd get this fixed "for free". The relevant VS Code issues are https://github.com/microsoft/vscode/issues/77140 and https://github.com/microsoft/vscode/issues/50140 .

[reapler]

If someone is looking for a solution, i have created this extension https://github.com/reapler/vscode-cfold because the preprocessor directives has driven me mad :)

[HunterZ]

I want to make sure that this bug covers the ability to automatically (on either file open, or user command) fold inactive code regions (especially due to preprocessor macros). The bug title+description don't make this clear, so I wrote bug #5020 which was closed as a duplicate of this. Thanks.

[soul4soul]

After a year of being annoyed I finally came to file this bug. I wasn't too surprised to see many beat me to it. I miss C/C++ code folding which I have come to love from VS. I'm excited to see this has been moved to in progress. 🐱‍🏍

[KaeLL]

Over 3 years later.... This feature alone is the only reason I use Eclipse for a component in my project that makes extensive usage of conditional compilation macros.

[sean-mcmanus]

Accurate C++ code folding is available in https://github.com/microsoft/vscode-cpptools/releases/tag/0.28.0-insiders2 . Let us know if anyone find any issues with it.

[akbyrd]

Issue 1
Code folding does not work on new files set to C++ language mode. They revert to indentation based folding.

Issue 2
Switch cases with braces fold differently than everything else. Everything else folds up to the keyword. Cases only fold up to the opening brace. Note the position of the folding buttons in this image. The second arrows is next to switch while the third arrow is on the brace after case.

And here is the inconsistency that results

Issue 3
Switch cases without braces do not fold.

There's room for debate here, as the case contents are not a scope, but personally I'd like to be able to fold them as they are still a logical block of code, if not a lexical scope.

Issue 4
It's obnoxious code, but this if doesn't fold to a closing brace at all.

Issue 5
Multi-line macros do not fold.

I have some quick and dirty tests here in the form of .cpp files with various code examples that should or should not fold.

[sean-mcmanus]

@akbyrd Issue 1 has the same root cause as https://github.com/microsoft/vscode-cpptools/issues/4143, i.e. none of our language server features will work until the file is saved.

Issue 2 is because "case:" has no '{' associated with it in the C++ language like the other if/switch blocks, so it's treated like all other {} blocks, e.g. your code could be

case 0:
int i;
{
}
break;

The {... looks odd, but we can't do what VS does until VS Code makes changes (which has existing issues tracking it).

Issue 3: I filed a feature request on VS at https://developercommunity.visualstudio.com/idea/1020490/c-intellisense-add-code-folding-for-case-regions.html . Our implementation is shared with VS.

Issue 4: What is the result you expect in this case? It appears to fold correctly to me.

Issue 5: I've filed a feature request on VS at https://developercommunity.visualstudio.com/idea/1020893/c-intellisense-multiline-macros-dont-generate-a-co.html . I don't see it in your screenshot, but the "if" block is supposed to generate a code folding region (so let us know if you're not getting that).

[akbyrd]

Issue 1 has the same root cause as #4143, i.e. none of our language server features will work until the file is saved.

I copy code into a temp file quite frequently. This was the very first issue I encountered.

Issue 2 is because "case:" has no '{' associated with it in the C++ language like the other if/switch blocks,

Indeed, case doesn't introduce a scope in C++, but in your AST you likely have a case node followed by a scope node. That's a pattern you can handle to associate the braces with the case when they appear together. This is essentially how I've handled it (but at the token level) and it has worked quite well.

Issue 4: What is the result you expect in this case? It appears to fold correctly to me.

Apologies. You are correct. However, it is incorrect when the the active preprocessor block is reversed.

In this case I expect it to fold to the closing brace on line 39, which is in the active preprocessor region. If it were doing so, lines 38 and 39 would not be visible.

Perhaps it's assuming the first preprocessor block is the active one?

Issue 5: I don't see it in your screenshot, but the "if" block is supposed to generate a code folding region (so let us know if you're not getting that).

The if in that example does not generate a code folding region.

[sean-mcmanus]

@akbyrd Oh, issue 4 is unexpected because it doesn't repro with VS's implementation, so it implies that we somehow regressed that case or did something differently with our changes. I've filed bug https://github.com/microsoft/vscode-cpptools/issues/5429 .

I wasn't reproing issue 5 because my repro was slightly different with { on the same line as the if. I've filed VS bug https://developercommunity.visualstudio.com/content/problem/1021278/c-intellisense-code-folding-works-in-a-macro-defin.html .

Did you want us to add a setting to disable Code Folding with our extension so it can be provided by the vsc-cpp-folding extension? We thought about that but were going to wait for complaints before adding another enable/disable setting.

[akbyrd]

As a backup, yes, that would be helpful.

That said, I'd much rather use the official plugin. It's already 90% there, so I expect I'll be able to use it. The new file behavior and macro folding are the only blockers I've encountered so far.

Also, to clarify Issue 5, I would expect that the macro contents themselves fold, independent of whether the if block in the macro folds. I'm not terribly worried about the if, personally.

In the example, I'd expect that lines 20-21 and 23-27 are foldable.

[sean-mcmanus]

A C_Cpp.codeFolding ("Enabled"/"Disabled") setting has been added for 0.28.0 (not released yet): https://github.com/microsoft/vscode-cpptools/pull/5435 .

There is no ETA on when the blocking issues are going to be fixed.

[KaeLL]

Accurate C++ code folding is available in https://github.com/microsoft/vscode-cpptools/releases/tag/0.28.0-insiders2 . Let us know if anyone find any issues with it.

Ok. I understand that this issue is actually an umbrella for a lot of small issues related to how C/C++ code should be folded. I also believe the following problem, which are different issues about the same problem, indentation folding, is the most prominent of the bunch:
https://github.com/microsoft/vscode-cpptools/issues/1584
https://github.com/microsoft/vscode-cpptools/issues/2116
https://github.com/microsoft/vscode-cpptools/issues/3589
https://github.com/microsoft/vscode/issues/57696

I just checked, it's still not fixed, and indentation-based folding is still at play here, so I'm not sure what you mean by "Accurate"?

[akbyrd]

It's only in the insiders build of the plugin. If you follow the link it has instructions for enabling the insiders branch of the cpp plugin.

[KaeLL]

It's only in the insiders build of the plugin. If you follow the link it has instructions for enabling the insiders branch of the cpp plugin.

Here's the link to my settings.json file backup I update every time I change something in case you think I just added this setting. It's been enabled for quite a while.
https://pastebin.com/txMGa5Et

[elahehrashedi]

This issue is fixed in 0.28.0.
0.28.0 release: https://github.com/microsoft/vscode-cpptools/releases/tag/0.28.0

[sean-mcmanus]

@KaeLL Are you still reproing those issues with 0.28.0? I'm not able to repro those issues. Could you file a new issue with more repro details?

[sean-mcmanus]

@ret394 @KaeLL Yeah, our extension doesn't process unsaved files, so it'll fall back to use the previous code folding behavior provided by VS. You can upvote the unsaved file issue at https://github.com/microsoft/vscode-cpptools/issues/3343 .

[KaeLL]

The file was saved, for heaven's sake.
Open VS, open a new file, write that code, save it as trash.c, and there'll be no collapse arrow for the curly brackets (the main function block of code), only the individual preprocessor directives.
Indent the directives by 1 tab, and the collapse arrow shows up for the curly brackets and disappear for the directives, proving it's still indentation based folding. I'm using the 0.28.0 version of the extension, with the 1.45.1 version of VSCode on Clear Linux.
Here's my settings.json

{
    "editor.fontFamily": "'Cascadia Code', 'Source Code Pro Medium', 'Ubuntu Mono', 'Cascadia Mono'",
    "editor.fontSize": 16,
    "editor.accessibilitySupport": "off",
    "editor.wordWrap": "on",
    "editor.renderControlCharacters": true,
    "editor.renderWhitespace": "all",
    "editor.smoothScrolling": true,
    "editor.fontLigatures": true,
    "editor.cursorSmoothCaretAnimation": true,
    "editor.minimap.enabled": false,
    "editor.quickSuggestionsDelay": 0,
    "editor.renderLineHighlight": "all",

    "[c]": {
        "editor.wordWrapColumn": 8000,
        "editor.acceptSuggestionOnEnter": "off",
        "editor.detectIndentation": false,
        "editor.dragAndDrop": false,
        "editor.emptySelectionClipboard": false,
        "editor.insertSpaces": false,
        "editor.showFoldingControls": "always",
        "editor.wordBasedSuggestions": false,
        "editor.acceptSuggestionOnCommitCharacter": false,
        "editor.autoClosingBrackets": "beforeWhitespace",
        "editor.autoClosingQuotes": "beforeWhitespace",
        "editor.autoSurround": "brackets",
        "editor.copyWithSyntaxHighlighting": false,
        // "editor.defaultFormatter": "ms-vscode.cpptools",
        "editor.foldingStrategy": "indentation",
        // "editor.formatOnType": true,
        "editor.largeFileOptimizations": false,
    },

    "files.enableTrash": false,
    // "files.insertFinalNewline": true,
    "files.trimFinalNewlines": true,
    "files.trimTrailingWhitespace": true,
    "files.hotExit": "off",
    // "files.watcherExclude": {
    // //   "**/.**":true
    //  "**/*.old/**":true,
    // },
    // "search.exclude": {
    //  "**/*.old/**":true,
    //  "**/[.]":true,
    //  "**/esp-idf/**":true
    // },

    "workbench.editor.enablePreview": false,
    "workbench.editor.enablePreviewFromQuickOpen": false,
    "workbench.editor.highlightModifiedTabs": true,
    "workbench.settings.editor": "json",
    "workbench.settings.useSplitJSON": true,
    "workbench.settings.openDefaultSettings": true,
    "workbench.colorTheme": "Default High Contrast",
    "workbench.colorCustomizations": {
        // "editorWhitespace.foreground": "#000000a0",
        "editorWhitespace.foreground": "#ffffff50",
        // "editor.selectionBackground": "#ffffffc2",
        // "editor.selectionHighlightBackground": "#00000000"
    },

    "window.menuBarVisibility": "toggle",
    "terminal.integrated.fontFamily": "'Cascadia Mono', 'Source Code Pro Medium', 'Ubuntu Mono'",
    "terminal.integrated.cursorBlinking": true,
    "terminal.integrated.cursorStyle": "line",
    "terminal.integrated.fontSize": 16,
    "terminal.integrated.scrollback": 18446744073709551615,

    "C_Cpp.clang_format_path": "/usr/bin/clang-format",

    "C_Cpp.experimentalFeatures": "Enabled",
    "C_Cpp.updateChannel": "Insiders",
    "C_Cpp.loggingLevel": "Information",

    "diffEditor.ignoreTrimWhitespace": false,
    "breadcrumbs.enabled": true,
    "breadcrumbs.symbolSortOrder": "type",
    "files.associations": {
        "*.h": "c"
    },
    "window.zoomLevel": 0,
    "C_Cpp.autoAddFileAssociations": false,
    "C_Cpp.clang_format_sortIncludes": false,
    "C_Cpp.default.browse.limitSymbolsToIncludedHeaders": false,
    "C_Cpp.default.cppStandard": "c++20",
    "C_Cpp.default.cStandard": "c11",
    "C_Cpp.default.intelliSenseMode": "gcc-x64",
    "C_Cpp.suggestSnippets": false,
    "C_Cpp.vcpkg.enabled": false,
}

I have nothing more to add. The issue exists, but if it's happening only to me, then it's not happening and it's fixed for all intents and purposes, and I no longer care enough to pursue to the end. Might as well close the thread. Good day.

[sean-mcmanus]

@KaeLL It's caused by your setting "editor.foldingStrategy": "indentation". The issue should be fixed if you remove that.

[yuchongbo]

I tried using the .28 version cpp extension, vscode version 1.45.1 and found an interesting thing.
the case block cannot be folded in [switch] statement in an exist .cpp file, but when I copied the same content to a new created cpp file, case block folding works!

[akbyrd]

VS Code seems to cache the folding regions of files. When you open a folder or workspace it saves your open files and some other state. I _think_ folding is part of that state. I haven't played around with it enough to know how to reliably reset that state. Maybe editing the file? Closing all files and clearing editor history? Just a thought.

[sean-mcmanus]

@yuchongbo The case folding is being tracked by https://github.com/microsoft/vscode-cpptools/issues/5523 . The fact that it starts working when it's copied to unsaved/new file is due to the fact that our extension only works on "file"-based URIs (and not the "untitled" URI scheme), which is tracked by https://github.com/microsoft/vscode-cpptools/issues/3343 .