export "something" { } wrong parsing

[FoxOneReal]

Describe the bug
I have something like this

extern "OldAsmCall" {
	void func1();
	void func2();
}

in my sources (old VDSP compiler). Doxygen parse this as extern variable OldAsmCall with intializer { void func1() and normal function void func2()

extern "C" { } or "C++" do parsed normally

Expected behavior
Expected to see extern void func1() and extern void func2()

Screenshots

Version
Tested 1.9.2

[albert-github]

Is the VDSP the VisualDSP compiler from Analogous Devices (which version) or is it another compiler?

Is the meaning of extern "OldAsmCall" { similar to extern "C" {?
Doxygen only supports extern "C" and extern "C++" and in the C / C++ standard I did not find any reference to OldAsmCall and doxygen doesn't understand it.
In the manual from mentioned compiler I could not find a reference to this type of construct though.

Best way to go is to write a small filter, see FILTER_PATTERNS and INPUT_FILTER (a filter like INPUT_FILTER = "sed -e 's/extern *\"OldAsmCall\"/extern \"C\"/'" would probably be sufficient).

[FoxOneReal]

You are right! It is VisualDSP++ compiler from Analog Devices. And there is extern OldAsmCall in documentation (C Compiler And Library Manual for ADSP-218x DSPs section Legacy Support page C-3, 1-157 also and more)

extern string-literal declaration where string-literal - The name of the required language linkage. The standard guarantes only two language linkages to be supported: "C" and "C++" I mean it does not restrict existing of some other language linkage But I thought Doxygen ignores language linkage at all. It's useless for Doxygen. I was pretty surprised it was parsed as a variable declaration

I've got your idea to use INPUT_FILTER. Thanks! Sadly, there is no sed on windows system. And I don't understand how FILTER_PATTERNS may help.

[albert-github]

The FILTER_PATTERN is similar to INPUT_FILTER though it just operates on files with a specific extension, the INPUT_FILTER operates on all other files.
For sed there are some alternatives on windows:

• install (part of) Cygwin, probably a bit of an overkill
• install, part of , the GNU tools for windows, search for gnu sed windows
• search the web for sed replacement windows to get some ideas
• write your own filter in your preferred language (C / C++, Python, perl, ...)

[FoxOneReal]

Anyway INPUT_FILTER is workaround. Is such behavior a doxygen bug? or clang bug? or something else?

[albert-github]

I see extern "OldAsmCall" as not strict standard C / C++ and in the manual you quoted it is under "Legacy Support".

I looked (again) in the C++ standard (after rereading your comment: "extern string-literal declaration where string-literal - The name of the required language linkage. The standard guarantes only two language linkages to be supported: "C" and "C++" I mean it does not restrict existing of some other language linkage ") and see in paragraph 9.11 Linkage Specification:

Linkage (6.6) between C++ and non-C++ code fragments can be achieved using a linkage-specification:
    linkage-specification:
        extern string-literal { declaration-seqopt }
        extern string-literal declaration
The string-literal indicates the required language linkage. This document specifies the semantics for the
string-literals "C" and "C++". Use of a string-literal other than "C" or "C++" is conditionally-supported, with
implementation-defined semantics.

So it indeed looks like "OldAsmCall" should be supported.

[albert-github]

I've just pushed a proposed patch, pull request #8842

[albert-github]

Code has been integrated in master on GitHub (please don't close the issue as this will be done at the moment of an official release).

[doxygen]

This issue was previously marked 'fixed but not released',
which means it should be fixed in doxygen version 1.9.3.
Please verify if this is indeed the case. Reopen the
issue if you think it is not fixed and please include any additional information
that you think can be relevant (preferably in the form of a self-contained example).