C++: fully qualified return type breaks parsing prototypes

[b4n]

The name of the parser:

C++

The command line you used to run ctags:

$ ctags --options=NONE --C++-kinds=+p -o- foo.cxx

The content of input file:

#include <string>

::std::string bar();
::std::string baz() { return "not a prototype"; }

The tags output you are not satisfied with:

baz	foo.cxx	/^::std::string baz() { return "not a prototype"; }$/;"	f	typeref:typename:::std::string

The tags output you expect:

bar	foo.cxx	/^::std::string bar();$/;"	p	typeref:typename:::std::string	file:
baz	foo.cxx	/^::std::string baz() { return "not a prototype"; }$/;"	f	typeref:typename:::std::string

The version of ctags:

$ ./ctags --version
Universal Ctags 6.0.0(c260d9e8), Copyright (C) 2015-2022 Universal Ctags Team
Universal Ctags is derived from Exuberant Ctags.
Exuberant Ctags 5.8, Copyright (C) 1996-2009 Darren Hiebert
  Compiled: Apr  6 2023, 15:34:13
  URL: https://ctags.io/
  Output version: 0.0
  Optional compiled features: +wildcards, +regex, +iconv, +option-directory, +xpath, +yaml, +packcc, +optscript, +pcre2

How do you get ctags binary:

Built it locally under Debian GNU/Linux Testing.

Details:

If you remove the leading :: from the return type (e.g. remove the FQ property) for the prototype that is missing here, it is properly recognized:

#include <string>

std::string bar();
::std::string baz() { return "not a prototype"; }

$ ctags --options=NONE --C++-kinds=+p -o- foo.cxx
bar	foo.cxx	/^std::string bar();$/;"	p	typeref:typename:std::string	file:
baz	foo.cxx	/^::std::string baz() { return "not a prototype"; }$/;"	f	typeref:typename:::std::string

This seems to happen in any context (e.g. it's the same inside a class or such, and same with a pure virtual method using a FQ return type).

[masatake]

About the reported case, the following change fixes the issue.
I'll take more time for this.

diff --git a/parsers/cxx/cxx_parser.c b/parsers/cxx/cxx_parser.c
index 63256ba8a..6ed9a83dd 100644
--- a/parsers/cxx/cxx_parser.c
+++ b/parsers/cxx/cxx_parser.c
@@ -1497,7 +1497,8 @@ void cxxParserAnalyzeOtherStatement(void)
 
        CXXToken * t = cxxTokenChainFirst(g_cxx.pTokenChain);
 
-       if(!cxxTokenTypeIsOneOf(t,CXXTokenTypeIdentifier | CXXTokenTypeKeyword))
+       if(!cxxTokenTypeIsOneOf(t,CXXTokenTypeIdentifier | CXXTokenTypeKeyword
+                                                       | CXXTokenTypeMultipleColons))
        {
                CXX_DEBUG_LEAVE_TEXT("Statement does not start with an identifier or keyword");
                return;

[b4n]

@masatake you rock, thanks! I'll test this in the coming days. It's really annoying me lately as I'm working a lot on code full of these kind of pure virtual prototypes, and it breaks autocompletion.

[masatake]

@b4n, thank you for testing. I opened the pull request.