[PATCH] D64115: [WebAssembly] Prevent inline assembly from being mangled by SjLj
Guanzhong Chen via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 2 17:23:24 PDT 2019
quantum created this revision.
quantum added reviewers: aheejin, tlively.
Herald added subscribers: llvm-commits, sunfish, hiraditya, jgravelle-google, sbc100, dschuff.
Herald added a project: LLVM.
Before, inline assembly gets mangled by the SjLj transformation.
For example, in a function with setjmp/longjmp, this LLVM IR code
call void asm sideeffect "", ""()
would be transformed into
call void @__invoke_void(void ()* asm sideeffect "", "")
This is invalid, and results in the error:
Cannot take the address of an inline asm!
In this diff, we skip the transformation for inline assembly.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D64115
Files:
llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
Index: llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
===================================================================
--- llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
+++ llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
@@ -188,6 +188,27 @@
; CHECK-NEXT: call void @emscripten_longjmp_jmpbuf(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 5) #1
}
+; Test inline asm handling
+define hidden void @inline_asm() #0 {
+; CHECK-LABEL: @inline_asm
+entry:
+ %env = alloca [1 x %struct.__jmp_buf_tag], align 16
+ %arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %env, i32 0, i32 0
+ %call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #4
+ %cmp = icmp eq i32 %call, 0
+ br i1 %cmp, label %if.then, label %if.else
+
+if.then: ; preds = %entry
+; CHECK: call void asm sideeffect "", ""()
+ call void asm sideeffect "", ""()
+ %arraydecay1 = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %env, i32 0, i32 0
+ call void @longjmp(%struct.__jmp_buf_tag* %arraydecay1, i32 1) #5
+ unreachable
+
+if.else: ; preds = %entry
+ ret void
+}
+
declare void @foo()
; Function Attrs: returns_twice
declare i32 @setjmp(%struct.__jmp_buf_tag*) #0
Index: llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
===================================================================
--- llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
+++ llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
@@ -961,7 +961,7 @@
continue;
const Value *Callee = CI->getCalledValue();
- if (!canLongjmp(M, Callee))
+ if (!canLongjmp(M, Callee) || isa<InlineAsm>(Callee))
continue;
Value *Threw = nullptr;
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