doc: PeerManagerImpl omitted by Doxygen #28377

Current behaviour

PeerManagerImpl and its methods are not processed by Doxygen.

Expected behaviour

PeerManagerImpl should be documented. I didn't check if other Impl classes have the same issue.

Apart from documentation of this class being useful, it's quite annoying to not have the full caller graph for block and header validation.

Steps to reproduce

./autogen
./configure --enable-tests --enable-wallet --enable-zmq --with-gui --disable-bench --disable-fuzz-binary 
make docs

In Safari visit in index.html and search for PeerManagerImpl.

Relevant log output

https://gist.githubusercontent.com/Sjors/be63a50000e40dcc74e22886f5ca213a/raw/c0ed70184a1f5b82a291ad8b49c62862a8cdea41/log.txt

Several messages related to PeerManagerImpl:

/Users/sjors/dev/bitcoin-docs/src/net_processing.cpp:1429: warning: documented symbol 'void PeerManagerImpl::AddTxAnnouncement' was not declared or defined.
/Users/sjors/dev/bitcoin-docs/src/net_processing.cpp:1456: warning: no matching class member found for 
  void PeerManagerImpl::UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds)
…
/Users/sjors/dev/bitcoin-docs/src/net_processing.cpp:1953: warning: no uniquely matching class member found for 
  void PeerManagerImpl::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload)
Possible candidates:
  'void TestSubscriber::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override' at line 41 of file /Users/sjors/dev/bitcoin-docs/src/test/validation_block_tests.cpp
  'virtual void CValidationInterface::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload)' at line 92 of file /Users/sjors/dev/bitcoin-docs/src/validationinterface.h
  'void CMainSignals::UpdatedBlockTip(const CBlockIndex *, const CBlockIndex *, bool fInitialDownload)' at line 199 of file /Users/sjors/dev/bitcoin-docs/src/validationinterface.h
  'void CZMQNotificationInterface::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) override' at line 38 of file /Users/sjors/dev/bitcoin-docs/src/zmq/zmqnotificationinterface.h
...

How did you obtain Bitcoin Core

Compiled from source

What version of Bitcoin Core are you using?

master@a4e0bcb6c9a8db5a74c74c5cddbb065ba9182482

Operating system and version

MacOS Ventura 13.5.1

Machine specifications

Doxygen 1.9.7

Probably an upstream doxygen issue, so there is nothing that can be done here, no?

Could be, or we're doing something wrong with how we document these implementation classes without header files?

I haven't seen a correct and complete doxygen call graph, except for the most trivial cases, yet, so I'd be surprised if this wasn't a doxygen bug.

Ok, so incomplete call graphs are a common issue? Some with entirely missing classes though? I can't it via search.

Jup, for example anything inside a lambda is ignored completely. See https://doxygen.bitcoincore.org/class_r_p_c_help_man.html which is empty and shows no call graphs at all.

AppInitServers is also completely omitted: https://doxygen.bitcoincore.org/init_8cpp.html#a29beb68bc259d98d5c425eb14f63ea81

Closing out of despair :-)