pcbjam/docs/features/fork-cleanup/01-revert-dead-code.md

01 — Revert dead code

~480 lines of fork diff across ~22 upstream files compile only in configurations the shipping build never uses. Reverting them is pure subtraction: zero behavior change to the WASM product, and it removes the single largest tranche of divergence.

A. #ifdef KICAD_IPC_API gating — 18 files, ~115 lines

The gates are dead. scripts/kicad/build-kicad-target.sh:354 passes -DKICAD_IPC_API=ON and links a wasm-built libprotobuf.a (-DProtobuf_LIBRARY=${SYSROOT}/lib/libprotobuf.a). So every #ifdef KICAD_IPC_API guard is always taken — the protobuf path always compiles. The OFF configuration these gates nominally enable cannot even link: the class headers (pad.h, zone.h, footprint.h, pcb_track.h:292,401,751, …) still declare void Serialize(google::protobuf::Any&) const override; unconditionally, so compiling out the definitions would leave undefined vtable symbols. Upstream confirms this is deliberate — protobuf is "required even when the IPC API is not enabled" (dev-docs build page), so the gating is not upstreamable either.

Files to revert to pristine upstream (all from commit e6a59ab94a):

common/eda_shape.cpp          common/eda_text.cpp           common/netclass.cpp
include/api/api_utils.h        pcbnew/api/api_pcb_utils.h    pcbnew/board_connected_item.cpp
pcbnew/board_stackup_manager/board_stackup.cpp              pcbnew/footprint.cpp
pcbnew/pad.cpp                 pcbnew/padstack.cpp           pcbnew/pcb_dimension.cpp
pcbnew/pcb_field.cpp           pcbnew/pcb_group.cpp          pcbnew/pcb_shape.cpp
pcbnew/pcb_text.cpp            pcbnew/pcb_textbox.cpp        pcbnew/pcb_track.cpp
pcbnew/zone.cpp

Note an internal inconsistency that confirms the gates were never exercised: netclass.cpp adds #else stub bodies for the vtable, but eda_shape.cpp/eda_text.cpp do not — an actual KICAD_IPC_API=OFF build would fail to link regardless. Just revert all 18.

B. include/gal/opengl/kiglew.h — +189/−1, dead

The +189-line #if defined(__EMSCRIPTEN__) block (GLEW stubs, glewInit no-op, glVertex2d→glVertex2f wrappers, display-list / lighting no-ops) was added for the old LEGACY_GL_EMULATION 3D-viewer path. But:

• The OpenGL GAL is compiled only if(NOT EMSCRIPTEN) (since the WebGL GAL split).
• The live WebGL GAL uses its own new header, include/gal/webgl/kiglew.h.
• The 3D viewer is not built (KICAD_BUILD_3D_VIEWER_WASM=OFF).

No wasm-compiled translation unit includes this header. The block only perturbs native builds. Revert. If the 3D viewer comes back via WebGL2 (see 10) it brings its own headers; if it ever needs a GL/ shim, use an include-path-shadowed header in a new dir — the pattern is already proven by include/gal/webgl/kiglew.h and the existing wasm/stubs/GL/.

C. common/gal/opengl/opengl_gal.cpp — +32/−31, dead

A Connect(...) → Bind(...) event-hookup refactor plus some GAL:: qualifications, to dodge a multiple-inheritance ambiguity that appeared during an early wasm compile. The file is excluded from the Emscripten build (same OpenGL-GAL exclusion as B), so this now only changes native behavior. Revert (or, if you like the modernization, upstream it — but reverting is cleaner).

D. Diagnostic call sites — ~30 lines, debugging a solved problem

The KI_DIAG_GAL / KI_DIAG_COROUTINE / KI_DIAG_CTOR macros (from include/kicad_wasm_diag.h, a fork-only header gated behind --diag build flags) were added to trace the Chrome Asyncify-rewind stall family — which is solved (see the chrome-asyncify-rewind-crash memory; fixed systemically by wasm-opt -O2 after --asyncify). The call sites are marked "TEMPORARY … Remove once the crash is fixed":

• common/tool/tool_manager.cpp +11 (dispatchInternal coroutine call)
• common/draw_panel_gal.cpp ~7 lines
• pcbnew/pcb_edit_frame.cpp 15 KI_DIAG_CTOR lines tracing ctor phases
• common/confirm.cpp +4 (unconditional wxFprintf(stderr, ...) before ShowModal — also affects native; move to the wx wasm modal shim if logging is still wanted)

Delete the call sites now. Keep the include/kicad_wasm_diag.h header itself (a new file, costs nothing) for ad-hoc reinsertion — its only in-upstream-file users disappear once the call sites go.

Net

Item	Files	~Lines	Risk
IPC-API gates	18	115	none (dead)
kiglew.h	1	190	none (dead in wasm; reverts a native-only change)
opengl_gal.cpp	1	63	none (dead in wasm)
Diagnostics	~3	30	none
Total	~23	~400	reverts also undo 4 accidental native-build changes

This is the recommended first action — see the sequencing.