From 7a0f3f2e3c8dc44f9c74b2f6e6165354239b63a8 Mon Sep 17 00:00:00 2001
From: Andrew Hayzen <andrew.hayzen@kdab.com>
Date: Fri, 15 Nov 2024 15:54:45 +0000
Subject: [PATCH] result: without exception do not throw when Result Err just
 abort

For WASM targets the `cc` crate changed to always set `-fno-exceptions`,
before only `-fignore-exceptions` was being set elsewhere, so now programs
fail to build when using `cxx` if any `throw` or `try ... catch` are used.

> error: cannot use 'throw' with exceptions disabled

Instead of throwing just abort.
---
 gen/src/write.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/gen/src/write.rs b/gen/src/write.rs
index 77e1da0b2..7d3d5380d 100644
--- a/gen/src/write.rs
+++ b/gen/src/write.rs
@@ -1123,7 +1123,19 @@ fn write_rust_function_shim_impl(
     if sig.throws {
         out.builtin.rust_error = true;
         writeln!(out, "  if (error$.ptr) {{");
+        writeln!(out, "#if defined(RUST_CXX_NO_EXCEPTIONS)");
+        writeln!(
+            out,
+            "    const auto msg = static_cast<char const *>(error$.ptr);"
+        );
+        writeln!(
+            out,
+            "    std::fprintf(stderr, \"Error: %s Aborting.\\n\", msg);"
+        );
+        writeln!(out, "    std::abort();");
+        writeln!(out, "#else");
         writeln!(out, "    throw ::rust::impl<::rust::Error>::error(error$);");
+        writeln!(out, "#endif");
         writeln!(out, "  }}");
     }
     if indirect_return {