Last bisection step. cpp/cpp_smoke.cpp reduced to a single extern 'C'
function that returns 42. No #include, no std::atomic, no std::mutex,
no std::thread. Only C++ things remaining are:
- cc::Build::new().cpp(true) in build.rs (C++ mode compile)
- cpp_link_stdlib('c++_shared') emitting -lc++_shared
If this still crashes with the same __init_tcb+4 / pthread_create
stack, we've conclusively proven the trigger is NOT any C++ code
that ends up in the final .so (everything gets dead-stripped
anyway because Rust never references wzp_cpp_hello). The trigger
must be either:
a) cargo:rustc-link-lib=c++_shared (adds NEEDED entry for
libc++_shared.so in the .so's dynamic table, causing the
dynamic linker to load libc++_shared.so at dlopen() time
alongside our .so), or
b) Some interaction between cpp(true) mode and the rest of the
build pipeline (toolchain flags, symbol visibility, etc.)
After this build we stop and write an incident report for the
WarzonePhone Tauri Android rewrite bisection so far.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Incremental bisection within Step E. E.4 (atomic + mutex + thread) still
crashed at __init_tcb. Drop mutex and thread, keep only std::atomic.
Build.rs still emits cargo:rustc-link-lib=c++_shared via
cpp_link_stdlib('c++_shared'), so the NEEDED entry for libc++_shared.so
in the final .so stays identical. Goal: if this crashes, the issue is
purely the dynamic link against libc++_shared (not thread/mutex code).
If it passes, the issue is actually std::thread or std::mutex use.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Bisection for the __init_tcb+4 crash that Step E introduced: drop the
full Oboe C++ build (200+ files, hundreds of KB of code) and replace
it with ONE tiny cpp/cpp_smoke.cpp that exercises the libc++ features
Oboe uses — std::atomic, std::mutex, std::thread — via an
extern "C" wzp_cpp_smoke() function that's exported but NEVER called
from Rust.
Still compiled with cpp_link_stdlib("c++_shared"), same as Oboe.
libc++_shared.so still copied into gen/android jniLibs. But no Oboe
headers, no Oboe source files, no -llog / -lOpenSLES links.
Hypothesis: if cpp_smoke.cpp alone reproduces the __init_tcb crash,
the trigger is "any libc++_shared link that references
std::thread/std::mutex" and Oboe is not the specific culprit. If it
launches cleanly, Oboe itself (its size, its static constructors, or
a specific header) is responsible — and we then bisect Oboe's
source tree.
fetch_oboe() and add_cpp_files_recursive() are retained in build.rs
with #[allow(dead_code)] so re-enabling the full Oboe compile is a
one-line edit once we've identified what's safe to include.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
