[PATCH] D101403: [WebAssembly] Error when wasm EH is used with Emscripten EH/SjLj

[Heejin Ahn via Phabricator via llvm-commits]

aheejin created this revision.
aheejin added reviewers: dschuff, tlively.
Herald added subscribers: wingo, ecnelises, sunfish, hiraditya, jgravelle-google, sbc100.
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- Error out when both Emscripten EH and wasm EH are used together, i.e., both `-enable-emscripten-cxx-exceptions` and `-exception-model=wasm` are given together. This will not happen if you use Emscripten, but this can happen when you call `llc` manually with wrong set of arguments.
- Currently we don't yet support using wasm EH with Emscripten SjLj. Unlike `-enable-emscripten-cxx-exceptions` which is turned on only when you use `emcc -s DISABLE_EXCEPTION_CATCHING=0`, `-enable-emscripten-sjlj` is turned on by Emscripten by default. So we error out only when it is turned on and `setjmp` or `longjmp` is actually used.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D101403

Files:
  llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
  llvm/test/CodeGen/WebAssembly/lower-em-ehsjlj-options.ll


Index: llvm/test/CodeGen/WebAssembly/lower-em-ehsjlj-options.ll
===================================================================
--- llvm/test/CodeGen/WebAssembly/lower-em-ehsjlj-options.ll
+++ llvm/test/CodeGen/WebAssembly/lower-em-ehsjlj-options.ll
@@ -3,6 +3,8 @@
 ; RUN: llc < %s | FileCheck %s --check-prefix=NONE
 ; RUN: not --crash llc < %s -enable-emscripten-cxx-exceptions -mtriple=wasm64-unknown-unknown 2>&1 | FileCheck %s --check-prefix=WASM64-EH
 ; RUN: not --crash llc < %s -enable-emscripten-sjlj -mtriple=wasm64-unknown-unknown 2>&1 | FileCheck %s --check-prefix=WASM64-SJLJ
+; RUN: not --crash llc < %s -enable-emscripten-cxx-exceptions -exception-model=wasm 2>&1 | FileCheck %s --check-prefix=WASM-EH-EM-EH
+; RUN: not --crash llc < %s -enable-emscripten-sjlj -exception-model=wasm 2>&1 | FileCheck %s --check-prefix=WASM-EH-EM-SJLJ
 
 target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
@@ -104,3 +106,5 @@
 
 ; WASM64-EH: LLVM ERROR: Emscripten EH/SjLj is not supported with wasm64 yet
 ; WASM64-SJLJ: LLVM ERROR: Emscripten EH/SjLj is not supported with wasm64 yet
+; WASM-EH-EM-EH: LLVM ERROR: -exception-model=wasm not allowed with -enable-emscripten-cxx-exceptions
+; WASM-EH-EM-SJLJ: LLVM ERROR: Emscripten SjLj is not supported with Wasm EH yet
Index: llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
===================================================================
--- llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
+++ llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
@@ -681,14 +681,19 @@
   bool LongjmpUsed = LongjmpF && !LongjmpF->use_empty();
   bool DoSjLj = EnableSjLj && (SetjmpUsed || LongjmpUsed);
 
-  if ((EnableEH || DoSjLj) &&
-      Triple(M.getTargetTriple()).getArch() == Triple::wasm64)
-    report_fatal_error("Emscripten EH/SjLj is not supported with wasm64 yet");
-
   auto *TPC = getAnalysisIfAvailable<TargetPassConfig>();
   assert(TPC && "Expected a TargetPassConfig");
   auto &TM = TPC->getTM<WebAssemblyTargetMachine>();
 
+  if ((EnableEH || DoSjLj) &&
+      Triple(M.getTargetTriple()).getArch() == Triple::wasm64)
+    report_fatal_error("Emscripten EH/SjLj is not supported with wasm64 yet");
+  if (EnableEH && TM.Options.ExceptionModel == ExceptionHandling::Wasm)
+    report_fatal_error("-exception-model=wasm not allowed with "
+                       "-enable-emscripten-cxx-exceptions");
+  if (DoSjLj && TM.Options.ExceptionModel == ExceptionHandling::Wasm)
+    report_fatal_error("Emscripten SjLj is not supported with Wasm EH yet");
+
   // Declare (or get) global variables __THREW__, __threwValue, and
   // getTempRet0/setTempRet0 function which are used in common for both
   // exception handling and setjmp/longjmp handling


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