MSVC C1202 Workaround Cleanup

Table of Contents

Problem

Three sets of files were split artificially to keep per-TU rfl template instantiation depth below MSVC's C1202 limit ("recursive type or function dependency context too complex"). The root cause was that rfl::internal::no_duplicate_field_names performs O(N²) constexpr comparisons across all variant field names; with trade_instrument (9 top-level alternatives, two of which are nested variants) and the accompanying trade sub-struct tree, the combined cost in a single translation unit exceeded MSVC's default 100 000- step constexpr budget.

The correct fix — [[#pragma constexpr_steps]] before the problematic rfl::json::read call — was applied in PR #786 (hotfix branch hotfix/msvc-windows-build-errors). Now the artificial splits can be removed and the code reorganised on genuine domain lines.

Already resolved

  • get_trade_detail_response_base / get_trade_detail_instrument_wrapper split in trade_protocol.hpp — removed in PR #786.
  • get_trade_detail_response now parsed in one rfl::json::read call in ClientManagerTrades.cpp with a TU-local pragma.

Solution

Three remaining groups of workarounds to clean up:

  1. Items 2 & 3 — Merge ClientManagerSetup.cpp and ClientManagerEvents.cpp back into ClientManager.cpp.
  2. Item 4 — Decompose register_other_instrument_handlers into one function per instrument family, matching the structure already used for FX and rates.

Item 2 & 3 — ClientManager file-split reversal

Background

ClientManagerSetup.cpp (testConnection, signup) and ClientManagerEvents.cpp (subscribeToEvent, unsubscribeFromEvent) were each extracted from ClientManager.cpp purely to reduce the rfl instantiation count in that TU. The files carry explicit comments to this effect.

Changes

File Action
projects/ores.qt.api/src/ClientManager.cpp Add pragma block; absorb 4 methods
projects/ores.qt.api/src/ClientManagerSetup.cpp Delete
projects/ores.qt.api/src/ClientManagerEvents.cpp Delete

No CMakeLists.txt change needed — the target uses GLOB_RECURSE *.cpp.

Pragma placement

Add once near the top of ClientManager.cpp, before the first rfl::json::read call: 

#ifdef _MSC_VER
#  pragma constexpr_depth(1024)
#  pragma constexpr_steps(1000000)
#endif

Method inventory

  • From ClientManagerSetup.cpp: testConnection(), signup()
  • From ClientManagerEvents.cpp: subscribeToEvent(), unsubscribeFromEvent()

Strip each file's licence header and its duplicate #include "ores.qt/ClientManager.hpp" line when absorbing into ClientManager.cpp.

Item 4 — Decompose register_other_instrument_handlers

Background

registrar_other_instruments.cpp registers handlers for six instrument families in a single function whose name ("other instruments") reflects its origin as a catch-all rather than a domain concept.

The existing registrar structure already splits by domain family for FX (registrar_fx.cpp → typed_fx_instrument_handler) and rates (registrar_rates.cpp → rates_instrument_handler). The same pattern should apply to the remaining families.

Current contents of register_other_instrument_handlers

Section Handler class Subjects
Bond bond_instrument_handler list, save, remove, history (4)
Credit credit_instrument_handler list, save, remove, history (4)
Typed equity typed_equity_instrument_handler 9 typed save operations
Commodity commodity_instrument_handler list, save, remove, history (4)
Composite composite_instrument_handler get_legs, list, save, remove, history (5)
Scripted scripted_instrument_handler list, save, remove, history (4)

Target state

One file per family, using the same naming convention as registrar_fx.cpp and registrar_rates.cpp:

New file New function Handler class
registrar_bond.cpp register_bond_handlers bond_instrument_handler
registrar_credit.cpp register_credit_handlers credit_instrument_handler
registrar_equity.cpp register_equity_handlers typed_equity_instrument_handler
registrar_commodity.cpp register_commodity_handlers commodity_instrument_handler
registrar_composite.cpp register_composite_handlers composite_instrument_handler
registrar_scripted.cpp register_scripted_handlers scripted_instrument_handler

Delete registrar_other_instruments.cpp.

No CMakeLists.txt change needed — ores.trading.core also uses GLOB_RECURSE.

registrar_detail.hpp

  • Remove the declaration of register_other_instrument_handlers.
  • Add six ORES_TRADING_CORE_EXPORT declarations with the same signature (nats, ctx, verifier; no http_base_url — that is only needed by the trade handlers).
  • Replace the MSVC C1202 comment with: Split by instrument family for domain clarity and parallel incremental builds.

registrar.cpp

Replace the single register_other_instrument_handlers call with six new calls and adjust subs.reserve(N) to the correct total.

Subscription count breakdown (verify by reading each existing registrar file):

  • register_bond_handlers: 4
  • register_credit_handlers: 4
  • register_equity_handlers: 9
  • register_commodity_handlers: 4
  • register_composite_handlers: 5
  • register_scripted_handlers: 4
  • Subtotal "other" replacement: 30

Read registrar_trades.cpp, registrar_rates.cpp, registrar_fx.cpp to get their exact counts, then set reserve to the true total.

Commit strategy

All work on the current hotfix/msvc-windows-build-errors branch.

  1. [qt] Merge ClientManagerSetup/Events back into ClientManager (items 2 & 3)
  2. [trading] Split register_other_instrument_handlers by instrument family (item 4)

Then push and update PR #786.

Verification

# No stale references remain
grep -rn "ClientManagerSetup\|ClientManagerEvents" projects/
grep -rn "register_other_instrument_handlers" projects/

# Build the affected targets (ask user to run)
make -C build/output/linux-clang-debug-make -j$(nproc) ores.qt.api.lib ores.trading.core.lib