diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -2668,6 +2668,11 @@ // Passing 'true' for doesNotReturn above won't generate the trap for us. if (TM.getTargetTriple().isPS4CPU()) Chain = DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, Chain); + // WebAssembly needs an unreachable instruction after a non-returning call, + // because the function return type can be different from __stack_chk_fail's + // return type (void). + if (TM.getTargetTriple().isWasm()) + Chain = DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, Chain); DAG.setRoot(Chain); } diff --git a/llvm/test/CodeGen/WebAssembly/stack-protector.ll b/llvm/test/CodeGen/WebAssembly/stack-protector.ll --- a/llvm/test/CodeGen/WebAssembly/stack-protector.ll +++ b/llvm/test/CodeGen/WebAssembly/stack-protector.ll @@ -1,13 +1,13 @@ ; RUN: llc -verify-machineinstrs -mtriple=wasm32-unknown-unknown < %s | FileCheck -check-prefix=WASM32 %s -; WASM32: i32.load 28 -; WASM32-NEXT: i32.ne -; WASM32-NEXT: br_if 0 - -; WASM32: __stack_chk_fail - @"\01LC" = internal constant [11 x i8] c"buf == %s\0A\00" ; <[11 x i8]*> [#uses=1] +; WASM32-LABEL: test +; WASM32: i32.load 28 +; WASM32: br_if 0 +; WASM32: call __stack_chk_fail +; WASM32-NEXT: unreachable + define void @test(i8* %a) nounwind ssp { entry: %a_addr = alloca i8* ; [#uses=2] @@ -25,6 +25,27 @@ ret void } +; WASM32-LABEL: test_return_i32 +; WASM32: call __stack_chk_fail +; WASM32-NEXT: unreachable + +define i32 @test_return_i32(i8* %a) nounwind ssp { +entry: + %a_addr = alloca i8* ; [#uses=2] + %buf = alloca [8 x i8] ; <[8 x i8]*> [#uses=2] + %"alloca point" = bitcast i32 0 to i32 ; [#uses=0] + store i8* %a, i8** %a_addr + %buf1 = bitcast [8 x i8]* %buf to i8* ; [#uses=1] + %0 = load i8*, i8** %a_addr, align 4 ; [#uses=1] + %1 = call i8* @strcpy(i8* %buf1, i8* %0) nounwind ; [#uses=0] + %buf2 = bitcast [8 x i8]* %buf to i8* ; [#uses=1] + %2 = call i32 (i8*, ...) @printf(i8* getelementptr ([11 x i8], [11 x i8]* @"\01LC", i32 0, i32 0), i8* %buf2) nounwind ; [#uses=0] + br label %return + +return: ; preds = %entry + ret i32 0 +} + declare i8* @strcpy(i8*, i8*) nounwind declare i32 @printf(i8*, ...) nounwind