[PATCH] D107687: [WebAssembly] Error out when Emscripten SjLj setjmp is used with Wasm EH

[Heejin Ahn via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGaca198cf748e: [WebAssembly] Error out when Emscripten SjLj setjmp is used with Wasm EH (authored by aheejin).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107687/new/

https://reviews.llvm.org/D107687

Files:
  llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
  llvm/test/CodeGen/WebAssembly/wasm-eh-em-sjlj-error.ll


Index: llvm/test/CodeGen/WebAssembly/wasm-eh-em-sjlj-error.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/WebAssembly/wasm-eh-em-sjlj-error.ll
@@ -0,0 +1,53 @@
+; RUN: not --crash llc < %s -enable-emscripten-sjlj -exception-model=wasm 2>&1 | FileCheck %s
+
+target triple = "wasm32-unknown-unknown"
+
+%struct.__jmp_buf_tag = type { [6 x i32], i32, [32 x i32] }
+
+define void @wasm_eh_emscripten_sjlj_error() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
+entry:
+  %buf = alloca [1 x %struct.__jmp_buf_tag], align 16
+  %arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
+  %call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
+  %arraydecay1 = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
+  br label %bb
+
+bb:
+  invoke void @foo()
+          to label %try.cont unwind label %catch.dispatch
+
+catch.dispatch:                                   ; preds = %entry
+  %0 = catchswitch within none [label %catch.start] unwind to caller
+
+catch.start:                                      ; preds = %catch.dispatch
+  %1 = catchpad within %0 [i8* null]
+  %2 = call i8* @llvm.wasm.get.exception(token %1)
+  %3 = call i32 @llvm.wasm.get.ehselector(token %1)
+  %4 = call i8* @__cxa_begin_catch(i8* %2) #2 [ "funclet"(token %1) ]
+  call void @__cxa_end_catch() [ "funclet"(token %1) ]
+  catchret from %1 to label %try.cont
+
+try.cont:                                         ; preds = %entry, %catch.start
+  ret void
+}
+
+declare void @foo()
+declare i32 @__gxx_wasm_personality_v0(...)
+; Function Attrs: nounwind
+declare i8* @llvm.wasm.get.exception(token) #0
+; Function Attrs: nounwind
+declare i32 @llvm.wasm.get.ehselector(token) #0
+declare i8* @__cxa_begin_catch(i8*)
+declare void @__cxa_end_catch()
+; Function Attrs: returns_twice
+declare i32 @setjmp(%struct.__jmp_buf_tag*) #0
+; Function Attrs: noreturn
+declare void @longjmp(%struct.__jmp_buf_tag*, i32) #1
+declare i8* @malloc(i32)
+declare void @free(i8*)
+
+attributes #0 = { returns_twice }
+attributes #1 = { noreturn }
+attributes #2 = { nounwind }
+
+; CHECK: LLVM ERROR: When using Wasm EH with Emscripten SjLj, there is a restriction that `setjmp` function call and exception cannot be used within the same function
Index: llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
===================================================================
--- llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
+++ llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
@@ -1105,7 +1105,10 @@
   for (unsigned I = 0; I < BBs.size(); I++) {
     BasicBlock *BB = BBs[I];
     for (Instruction &I : *BB) {
-      assert(!isa<InvokeInst>(&I));
+      if (isa<InvokeInst>(&I))
+        report_fatal_error("When using Wasm EH with Emscripten SjLj, there is "
+                           "a restriction that `setjmp` function call and "
+                           "exception cannot be used within the same function");
       auto *CI = dyn_cast<CallInst>(&I);
       if (!CI)
         continue;


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