[llvm] r346445 - [WebAssembly] Fix LowerEmscriptenEHSjLj when there's only longjmp
Heejin Ahn via llvm-commits
llvm-commits at lists.llvm.org
Thu Nov 8 14:56:26 PST 2018
Author: aheejin
Date: Thu Nov 8 14:56:26 2018
New Revision: 346445
URL: http://llvm.org/viewvc/llvm-project?rev=346445&view=rev
Log:
[WebAssembly] Fix LowerEmscriptenEHSjLj when there's only longjmp
Summary:
The pass incorrectly assumed if there's a longjmp declaration in the
module, there is also a setjmp function declaration. Fixed it, and now
the pass only converts longjmp and does not do any other transformation
when there's no setjmp declaration in the module.
Fixes PR39562.
Reviewers: jgravelle-google, sbc100
Subscribers: dschuff, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D54273
Added:
llvm/trunk/test/CodeGen/WebAssembly/lower-em-sjlj-longjmp-only.ll
Modified:
llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp?rev=346445&r1=346444&r2=346445&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp Thu Nov 8 14:56:26 2018
@@ -140,7 +140,17 @@
///
/// * Setjmp / Longjmp handling
///
-/// 7) In the function entry that calls setjmp, initialize setjmpTable and
+/// In case calls to longjmp() exists
+///
+/// 1) Lower
+/// longjmp(buf, value)
+/// into
+/// emscripten_longjmp_jmpbuf(buf, value)
+/// emscripten_longjmp_jmpbuf will be lowered to emscripten_longjmp later.
+///
+/// In case calls to setjmp() exists
+///
+/// 2) In the function entry that calls setjmp, initialize setjmpTable and
/// sejmpTableSize as follows:
/// setjmpTableSize = 4;
/// setjmpTable = (int *) malloc(40);
@@ -148,7 +158,7 @@
/// setjmpTable and setjmpTableSize are used in saveSetjmp() function in JS
/// code.
///
-/// 8) Lower
+/// 3) Lower
/// setjmp(buf)
/// into
/// setjmpTable = saveSetjmp(buf, label, setjmpTable, setjmpTableSize);
@@ -162,13 +172,8 @@
/// A BB with setjmp is split into two after setjmp call in order to make the
/// post-setjmp BB the possible destination of longjmp BB.
///
-/// 9) Lower
-/// longjmp(buf, value)
-/// into
-/// emscripten_longjmp_jmpbuf(buf, value)
-/// emscripten_longjmp_jmpbuf will be lowered to emscripten_longjmp later.
///
-/// 10) Lower every call that might longjmp into
+/// 4) Lower every call that might longjmp into
/// __THREW__ = 0;
/// call @__invoke_SIG(func, arg1, arg2)
/// %__THREW__.val = __THREW__;
@@ -189,21 +194,21 @@
/// ...
/// default: goto splitted next BB
/// }
-/// testSetjmp examines setjmpTable to see if there is a matching setjmp
-/// call. After calling an invoke wrapper, if a longjmp occurred, __THREW__
-/// will be the address of matching jmp_buf buffer and __threwValue be the
-/// second argument to longjmp. mem[__THREW__.val] is a setjmp ID that is
-/// stored in saveSetjmp. testSetjmp returns a setjmp label, a unique ID to
-/// each setjmp callsite. Label 0 means this longjmp buffer does not
-/// correspond to one of the setjmp callsites in this function, so in this
-/// case we just chain the longjmp to the caller. (Here we call
-/// emscripten_longjmp, which is different from emscripten_longjmp_jmpbuf.
-/// emscripten_longjmp_jmpbuf takes jmp_buf as its first argument, while
-/// emscripten_longjmp takes an int. Both of them will eventually be lowered
-/// to emscripten_longjmp in s2wasm, but here we need two signatures - we
-/// can't translate an int value to a jmp_buf.)
-/// Label -1 means no longjmp occurred. Otherwise we jump to the right
-/// post-setjmp BB based on the label.
+/// testSetjmp examines setjmpTable to see if there is a matching setjmp
+/// call. After calling an invoke wrapper, if a longjmp occurred, __THREW__
+/// will be the address of matching jmp_buf buffer and __threwValue be the
+/// second argument to longjmp. mem[__THREW__.val] is a setjmp ID that is
+/// stored in saveSetjmp. testSetjmp returns a setjmp label, a unique ID to
+/// each setjmp callsite. Label 0 means this longjmp buffer does not
+/// correspond to one of the setjmp callsites in this function, so in this
+/// case we just chain the longjmp to the caller. (Here we call
+/// emscripten_longjmp, which is different from emscripten_longjmp_jmpbuf.
+/// emscripten_longjmp_jmpbuf takes jmp_buf as its first argument, while
+/// emscripten_longjmp takes an int. Both of them will eventually be lowered
+/// to emscripten_longjmp in s2wasm, but here we need two signatures - we
+/// can't translate an int value to a jmp_buf.)
+/// Label -1 means no longjmp occurred. Otherwise we jump to the right
+/// post-setjmp BB based on the label.
///
///===----------------------------------------------------------------------===//
@@ -662,22 +667,6 @@ bool WebAssemblyLowerEmscriptenEHSjLj::r
if (DoSjLj) {
Changed = true; // We have setjmp or longjmp somewhere
- // Register saveSetjmp function
- FunctionType *SetjmpFTy = SetjmpF->getFunctionType();
- SmallVector<Type *, 4> Params = {SetjmpFTy->getParamType(0),
- IRB.getInt32Ty(), Type::getInt32PtrTy(C),
- IRB.getInt32Ty()};
- FunctionType *FTy =
- FunctionType::get(Type::getInt32PtrTy(C), Params, false);
- SaveSetjmpF = Function::Create(FTy, GlobalValue::ExternalLinkage,
- SaveSetjmpFName, &M);
-
- // Register testSetjmp function
- Params = {IRB.getInt32Ty(), Type::getInt32PtrTy(C), IRB.getInt32Ty()};
- FTy = FunctionType::get(IRB.getInt32Ty(), Params, false);
- TestSetjmpF = Function::Create(FTy, GlobalValue::ExternalLinkage,
- TestSetjmpFName, &M);
-
if (LongjmpF) {
// Replace all uses of longjmp with emscripten_longjmp_jmpbuf, which is
// defined in JS code
@@ -687,20 +676,39 @@ bool WebAssemblyLowerEmscriptenEHSjLj::r
LongjmpF->replaceAllUsesWith(EmLongjmpJmpbufF);
}
- FTy = FunctionType::get(IRB.getVoidTy(),
- {IRB.getInt32Ty(), IRB.getInt32Ty()}, false);
- EmLongjmpF =
- Function::Create(FTy, GlobalValue::ExternalLinkage, EmLongjmpFName, &M);
-
- // Only traverse functions that uses setjmp in order not to insert
- // unnecessary prep / cleanup code in every function
- SmallPtrSet<Function *, 8> SetjmpUsers;
- for (User *U : SetjmpF->users()) {
- auto *UI = cast<Instruction>(U);
- SetjmpUsers.insert(UI->getFunction());
+
+ if (SetjmpF) {
+ // Register saveSetjmp function
+ FunctionType *SetjmpFTy = SetjmpF->getFunctionType();
+ SmallVector<Type *, 4> Params = {SetjmpFTy->getParamType(0),
+ IRB.getInt32Ty(), Type::getInt32PtrTy(C),
+ IRB.getInt32Ty()};
+ FunctionType *FTy =
+ FunctionType::get(Type::getInt32PtrTy(C), Params, false);
+ SaveSetjmpF = Function::Create(FTy, GlobalValue::ExternalLinkage,
+ SaveSetjmpFName, &M);
+
+ // Register testSetjmp function
+ Params = {IRB.getInt32Ty(), Type::getInt32PtrTy(C), IRB.getInt32Ty()};
+ FTy = FunctionType::get(IRB.getInt32Ty(), Params, false);
+ TestSetjmpF = Function::Create(FTy, GlobalValue::ExternalLinkage,
+ TestSetjmpFName, &M);
+
+ FTy = FunctionType::get(IRB.getVoidTy(),
+ {IRB.getInt32Ty(), IRB.getInt32Ty()}, false);
+ EmLongjmpF = Function::Create(FTy, GlobalValue::ExternalLinkage,
+ EmLongjmpFName, &M);
+
+ // Only traverse functions that uses setjmp in order not to insert
+ // unnecessary prep / cleanup code in every function
+ SmallPtrSet<Function *, 8> SetjmpUsers;
+ for (User *U : SetjmpF->users()) {
+ auto *UI = cast<Instruction>(U);
+ SetjmpUsers.insert(UI->getFunction());
+ }
+ for (Function *F : SetjmpUsers)
+ runSjLjOnFunction(*F);
}
- for (Function *F : SetjmpUsers)
- runSjLjOnFunction(*F);
}
if (!Changed) {
Added: llvm/trunk/test/CodeGen/WebAssembly/lower-em-sjlj-longjmp-only.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WebAssembly/lower-em-sjlj-longjmp-only.ll?rev=346445&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/WebAssembly/lower-em-sjlj-longjmp-only.ll (added)
+++ llvm/trunk/test/CodeGen/WebAssembly/lower-em-sjlj-longjmp-only.ll Thu Nov 8 14:56:26 2018
@@ -0,0 +1,24 @@
+; RUN: opt < %s -wasm-lower-em-ehsjlj -S | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+%struct.__jmp_buf_tag = type { [6 x i32], i32, %struct.__sigset_t }
+%struct.__sigset_t = type { [32 x i32] }
+
+ at buffer = global [1 x %struct.__jmp_buf_tag] zeroinitializer, align 16
+
+; Tests if program does not crash when there's no setjmp function calls in the
+; module.
+
+; CHECK: call void @emscripten_longjmp_jmpbuf
+define void @longjmp_only() {
+entry:
+ call void @longjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @buffer, i32 0, i32 0), i32 1) #1
+ unreachable
+}
+
+; Function Attrs: noreturn nounwind
+declare void @longjmp(%struct.__jmp_buf_tag*, i32) #1
+
+attributes #1 = { noreturn nounwind }
More information about the llvm-commits
mailing list