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=================================================================
==2342311==ERROR: AddressSanitizer: heap-use-after-free on address 0x6030004541e4 at pc 0x7ff218ebce95 bp 0x7ff1fe2bc850 sp 0x7ff1fe2bc848
READ of size 4 at 0x6030004541e4 thread T6
    #0 0x7ff218ebce94 in wasm::Type::isTuple() const (/bin/../lib/libbinaryen.so+0x125e0e94)
    #1 0x7ff218fa852b in wasm::TypeBuilder::build() (/bin/../lib/libbinaryen.so+0x126cc52b)
    #2 0x7ff218fbda5f in wasm::Type::getLeastUpperBound(wasm::Type, wasm::Type) (/bin/../lib/libbinaryen.so+0x126e1a5f)
    #3 0x7ff2186f5006 in wasm::If::finalize() (/bin/../lib/libbinaryen.so+0x11e19006)
    #4 0x56004b397f60 in wasm::Walker<wasm::ReFinalize, wasm::OverriddenVisitor<wasm::ReFinalize, void> >::walk(wasm::Expression*&) (/bin/wasm-opt+0xce3f60)
    #5 0x7ff2178918ed in wasm::RemoveUnusedBrs::doWalkFunction(wasm::Function*) (/bin/../lib/libbinaryen.so+0x10fb58ed)
    #6 0x7ff2178973ec in wasm::WalkerPass<wasm::PostWalker<wasm::RemoveUnusedBrs, wasm::Visitor<wasm::Remove

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#include "a.h"

void a() {
  data = 42;
}

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commit 972d6299672f4508c805af5efd886bb87b0a22fe
Author: Alon Zakai <[email protected]>
Date:   Tue Apr 5 16:50:33 2022 -0700

    wip

diff --git a/src/passes/ConstantFieldPropagation.cpp b/src/passes/ConstantFieldPropagation.cpp
index e4e01dc0e..76f64535c 100644
--- a/src/passes/ConstantFieldPropagation.cpp
+++ b/src/passes/ConstantFieldPropagation.cpp

kripken

Emscripten as a linker for Zig and C

This shows how to build a nontrivial program using Zig+Emscripten or C+Emscripten. In both cases Emscripten is only used as a linker, that is the frontend is either zig or clang.

"Nontrivial" here means the program uses interesting Emscripten features:

• Asyncify
• Full GLES3 support
• GLFW3 support

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/*
 * Copyright 2011 The Emscripten Authors.  All rights reserved.
 * Emscripten is available under two separate licenses, the MIT license and the
 * University of Illinois/NCSA Open Source License.  Both these licenses can be
 * found in the LICENSE file.
 */

#include <stdio.h>
#include <errno.h>
#include <unistd.h>

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//
// Build with
//
// -pthread -s PROXY_TO_PTHREAD -s EXIT_RUNTIME
//

#include <stdlib.h>

#include <emscripten.h>
#include <emscripten/threading.h>

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# 1 "tests/core/test_atomic_cxx.cpp"
# 1 "<built-in>" 1
# 1 "<built-in>" 3
# 355 "<built-in>" 3
# 1 "<command line>" 1
# 1 "<built-in>" 2
# 1 "tests/core/test_atomic_cxx.cpp" 2
# 13 "tests/core/test_atomic_cxx.cpp"
# 1 "/home/azakai/Dev/emscripten/cache/sysroot/include/c++/v1/atomic" 1 3
# 577 "/home/azakai/Dev/emscripten/cache/sysroot/include/c++/v1/atomic" 3

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*.wasm
temp

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Building binaryen with zig cc

1. Add zigcc, zigc++ scripts because cmake doens't accept a compiler with spaces in the name like "zig cc".
2. The zigcc/zigc++ scripts can also add a target for cross-compiling as shown here.
3. Disable threads (perhaps cmake cross-compiling needs to be set up?).
4. Use a static build (otherwise cmake emits a .so - again, do we need cmake cross-compiling here?).
5. ninja stalls on the final links: it just hangs. To solve that, run ninja wasm-opt and so forth manually, as a specific build target works.

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extern "C" int foo();

int main() {
  foo();
}