W5

src/lib/wasm_trace.h

@@ -15,7 +15,11 @@
 #include <string>
 #include <vector>
 
-#if defined(__GNUG__)
+// The demangler is a host-side nicety for trap traces. wasi-libc++ does not
+// provide __cxa_demangle, and a wasm unit that merely includes uce_lib.h must
+// not pull it in as an unresolvable import — so it is host-only.
+#if defined(__GNUG__) && !defined(__wasm__)
+#define UCE_WASM_TRACE_HAVE_DEMANGLE 1
 #include <cxxabi.h>
 #endif
 
@@ -30,7 +34,7 @@ struct WasmTraceSummary
 
 inline std::string wasm_trace_demangle(const std::string& name)
 {
-#if defined(__GNUG__)
+#if defined(UCE_WASM_TRACE_HAVE_DEMANGLE)
 	// frame names look like "module!symbol"; demangle the symbol part
 	auto bang = name.find('!');
 	std::string prefix = bang == std::string::npos ? "" : name.substr(0, bang + 1);