[clang] [CodeGen][ObjC] Initial WebAssembly Support for GNUstep v2 (PR #183753)

[Jonathan Schleifer via cfe-commits]

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@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -triple wasm32-unknown-emscripten -fobjc-exceptions -fexceptions -exception-model=wasm -mllvm -wasm-enable-eh -emit-llvm -fobjc-runtime=gnustep-2.2 -o - %s | FileCheck %s
+
+void may_throw(void) {
+        @throw (id) 1;
+}
+
+int main(void) {
+        int retval = 0;
+        @try {
+                may_throw();
+                // CHECK: invoke void @may_throw()
+                // CHECK-NEXT: to label %[[INVOKE_CONT:.*]] unwind label %[[CATCH_DISPATCH:.*]]
+        }
+        // Check that the dispatch block has been emitted correctly.
+        // CHECK: [[CATCH_DISPATCH]]:
+        // CHECK-NEXT: %[[CATCHSWITCH:.*]] = catchswitch within none [label %[[CATCH_START:.*]] unwind to caller
+
+
+        // The native WASM EH uses the new exception handling IR instructions
+        // (catchswitch, catchpad, etc.) that are also used when targeting Windows MSVC.
+        // For SEH, we emit a catchpad instruction for each catch statement. On WASM, we
+        // merge all catch statements into one big catch block.
+
+        // CHECK: catchpad within %[[CATCHSWITCH]] [ptr @__objc_id_type_info, ptr null]
+
+        // We use the cxa functions instead of objc_{begin,end}_catch.
+        // CHECK: call ptr @__cxa_begin_catch
+        @catch(id a) {
+            retval = 1;
+        }
+        @catch(...) {
+            retval = 2;
+        }
+        return retval;
----------------
Midar wrote:

The test case should probably also contain a @finally to make sure that a.) it is there in the non-exception flow b.) in all catch handler flows c.) in the catch all and rethrow flow.

https://github.com/llvm/llvm-project/pull/183753