The executables precompile Qt since #7235, but the libcockatrice_*
static libraries still reparse the full Qt Core stack in every TU.
Measured over the tree after the IWYU pass: 380 MB of header parse in
the libraries, 92% of it reachable from qtcore_pch.h.
- Apply qtcore_pch.h to the 14 Qt Core static library targets
(skips libcockatrice_rng: its SFMT.c is C and cannot use a C++
precompiled header).
- Grow qtcore_pch.h with 25 QtCore headers that IWYU shows are
re-parsed across many TUs and were not already reachable from the
existing list (JSON/QUuid cluster, QSettings, item models,
threading, XmlStream, QTemporaryDir, ...).
- Grow qtwidgets_pch.h with 30 QtGui/QtWidgets headers (dialog
cluster, item views, QImageReader, ...).
Only stable Qt headers go into the PCH, so it rarely invalidates.
Test executables stay PCH-less: 1-3 TUs per target does not amortize
the extra precompile.
Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>
* [Build] Add precompiled headers for Qt-backed executables
Reparsing QtCore/QtGui/QtWidgets/QtNetwork in ~460 client translation
units is the dominant compilation cost. Precompile the two common layers:
- qtcore_pch.h (Qt Core only; safe even for headless Servatrice)
- qtwidgets_pch.h (adds Gui/Widgets/Network; used by Cockatrice and Oracle)
target_precompile_headers() requires CMake 3.16, now the project minimum.
Estimated 30-50% faster client rebuilds.
* [Build] Format qtwidgets precompiled header
clang-format include regrouping and a missing trailing newline.
* [Build] Add PCH-aware ccache sloppiness config; format cmake/pch headers
---------
Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>
