fn_registry/bash/functions/infra/build_wasm_cpp_app.md

name, kind, lang, domain, version, purity, signature, description, tags, uses_functions, uses_types, returns, returns_optional, error_type, imports, example, tested, tests, test_file_path, file_path, params, output

name	kind	lang	domain	version	purity	signature	description	tags	uses_functions	uses_types	returns	returns_optional	error_type	imports	example	tested	tests	test_file_path	file_path	params	output
build_wasm_cpp_app	function	bash	infra	0.1.0	impure	build_wasm_cpp_app(app_name: string, [--no-budget-check]) -> void	Compila una app C++ del registry (cpp/apps/<name>) a WASM via emscripten. Sale build/wasm/<name>/<name>.{html,js,wasm,wasm.gz}. Falla si gzip > 2 MB.	wasm emscripten cpp build gamedev				false	error_go_core		bash bash/functions/infra/build_wasm_cpp_app.sh engine_smoke	false			bash/functions/infra/build_wasm_cpp_app.sh	name desc app_name Nombre del directorio bajo cpp/apps/. Debe contener CMakeLists.txt self-sufficient (top-level project) con guard `if(EMSCRIPTEN)` para flags wasm. name desc --no-budget-check Opcional. Salta verificacion de tamaño (gzip < 2 MB hard, < 1.5 MB soft).	Reporte de tamaños en stdout. Crea build/wasm/<app>/<app>.html/.js/.wasm/.wasm.gz. Exit 3 si excede budget hard.

build_wasm_cpp_app

Compila apps C++ del registry a WebAssembly. Issue 0072d (parte del stack gamedev).

Requisitos

• emsdk instalado y activo en el shell, o presente en <repo>/emsdk/ (autoactiva).
• cpp/apps/<app>/CMakeLists.txt con bloque if(EMSCRIPTEN) ... endif() que define los flags wasm (USE_WEBGL2, FULL_ES3, ALLOW_MEMORY_GROWTH, etc.).
• cpp/CMakeLists.txt debe seguir tolerando configuracion via emcmake. La app target se elige con cmake --build $BUILD_DIR --target <app>.

Flujo

1. Localiza emcc en PATH o autoactiva <repo>/emsdk/emsdk_env.sh.
2. emcmake cmake -S cpp -B build/wasm/<app> -DCMAKE_BUILD_TYPE=MinSizeRel
3. cmake --build build/wasm/<app> --target <app> -j
4. gzip -9 -k <app>.wasm y brotli -q 11 -k <app>.wasm (si brotli disponible).
5. Reporta tamaños y compara contra budget (1.5 MB gzip soft, 2 MB hard).

Budgets

Limite	Valor	Comportamiento
Soft	1.5 MB gzip	Warning, sigue
Hard	2 MB gzip	Exit 3, falla

Skip con --no-budget-check.

Apps soportadas

Cualquier app bajo cpp/apps/<name>/ cuyo CMakeLists.txt defina target con flags emscripten. Probada con: engine_smoke (issue 0072a).

Errores comunes

• emcc no encontrado → instalar emsdk segun instrucciones del propio script.
• <app>.wasm no encontrado → fallo de build. Re-ejecutar con 2>&1 | tee para ver compiler errors.
• wasm.gz excede budget → revisar bloat, usar twiggy top o wasm-objdump -h. Ver issue 0072d.