Syntax causes tokenization to break for remainder of file

[alexr00]

Checklist

• This problem exists even with the setting "C_Cpp.enhancedColorization": "Disabled"
• This bug exists for C
• This bug exists for C++
• This bug exists for Objective-C
• This bug exists for Objective-C++

The code with a problem is:

Test::Test() : Base ("{}") {
   // Broken syntax highlight
}

It looks like:

It should look like:

It looks like things start to go wrong on the first curly brace, which ends up with these scopes:

punctuation.section.block.begin.bracket.curly.function.definition.special.constructor.cpp
meta.head.function.definition.special.constructor.cpp
meta.function.definition.special.constructor.cpp
source.cpp

[jeff-hykin]

Does this code use macros?

There's probably a more graceful way the syntax can handle this, but if the code isn't using utilizing the preprocessor I'd be very surprised if that code was valid.

[marzojr]

The code does not use macros or the preprocessor in any way and is perfectly valid in all versions of c++ ever; here is a full example that compiles:

struct Base {
    Base(const char *s_);
    const char *s;
};

struct Test : public Base {
    Test();
};

Base::Base(const char *s_) : s(s_) {}

Test::Test() : Base ("{}") {
   // Broken syntax highlight
}

You can place it on a c++ file and compile with any compiler.

Edit: live example.

[matter123]

@jeff-hykin constructors are allowed to call other constructors or the base constructor in the initializer list.

This is no different than

class Test {
std::string _member;
Test();
}

Test::Test(): _member("{}") {
}

Though both highlight correctly for me (if you ignore bracket highlighter getting confused)

[marzojr]

@matter123 It will break highlight if you add a space between _member and (. It seems like adding a space there combines with the curly braces in the string to break the highlighting.

[matter123]

@marzojr It seems that this may have been fixed sometime between the most recently published version and the version that vscode is using. You can manually install the "Better C++ Syntax" extension, to fix for now.

I finally, somewhat, have some time I can put into looking into #460, so hopefully, at some point, the version vscode is using should be able to be updated again.

[marzojr]

@matter123 I tried the extension you mentioned, and it does make the problem much better -- but it is still there.

Note that the curly braces in your screenshot are all highlighted as brackets, not as characters inside a character literal. Also, the closing parenthesis of the initializer, as well as the curly braces of the constructor, are incorrectly highlighted.

Exploring a bit, most of the syntax highlighting is correct with that extension, but curly braces, square brackets, and parenthesis, are all incorrectly highlighted for the remainder of the file -- they highlight as brackets while inside strings, and are not highlighted outside of strings.

Interestingly, changing from {} to {}[] in the character literal will fix the highlighting, probably because the grammar probably identifies it as a lambda introducer instead of as a scope.

[matter123]

Are your brackets colored via your color theme or via an extension like "Bracket Pair Colorizer 2"?

If you use Developer: Inspect Editor Tokens and Scopes (in the command palate), you should see that the grammar correctly marks the "{}" as string.quoted.double.cpp

[marzojr]

Hm, nice catch; the incorrect bracket highlighting is coming from "Bracker Pair Colorizer 2", and with it disabled, it seems that "Better C++ Syntax" fixes this issue.

[matter123]

Closing this as this is fixed in a released version.

[jeff-hykin]

Thanks for taking care of this.

And well, I guess consider me surprised, I didn't account for the case of an external initializer list. I guess I'm a bit too used to inline constructors.