[llvm] r369137 - [WebAssembly] Forbid use of EM_ASM with setjmp/longjmp
Guanzhong Chen via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 16 11:21:08 PDT 2019
Author: quantum
Date: Fri Aug 16 11:21:08 2019
New Revision: 369137
URL: http://llvm.org/viewvc/llvm-project?rev=369137&view=rev
Log:
[WebAssembly] Forbid use of EM_ASM with setjmp/longjmp
Summary:
We tried to support EM_ASM with setjmp/longjmp in binaryen. But with dynamic
linking thrown into the mix, the code is no longer understandable and cannot
be maintained. We also discovered more bugs in the EM_ASM handling code.
To ensure maintainability and correctness of the binaryen code, EM_ASM will
no longer be supported with setjmp/longjmp. This is probably fine since the
support was added recently and haven't be published.
Reviewers: tlively, sbc100, jgravelle-google, kripken
Reviewed By: tlively, kripken
Subscribers: dschuff, hiraditya, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66356
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=369137&r1=369136&r2=369137&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp Fri Aug 16 11:21:08 2019
@@ -274,6 +274,7 @@ class WebAssemblyLowerEmscriptenEHSjLj f
bool areAllExceptionsAllowed() const { return EHWhitelistSet.empty(); }
bool canLongjmp(Module &M, const Value *Callee) const;
+ bool isEmAsmCall(Module &M, const Value *Callee) const;
void rebuildSSA(Function &F);
@@ -537,6 +538,23 @@ bool WebAssemblyLowerEmscriptenEHSjLj::c
return true;
}
+bool WebAssemblyLowerEmscriptenEHSjLj::isEmAsmCall(Module &M,
+ const Value *Callee) const {
+ // This is an exhaustive list from Emscripten's <emscripten/em_asm.h>.
+ Function *EmAsmConstIntF = M.getFunction("emscripten_asm_const_int");
+ Function *EmAsmConstDoubleF = M.getFunction("emscripten_asm_const_double");
+ Function *EmAsmConstIntSyncMainF =
+ M.getFunction("emscripten_asm_const_int_sync_on_main_thread");
+ Function *EmAsmConstDoubleSyncMainF =
+ M.getFunction("emscripten_asm_const_double_sync_on_main_thread");
+ Function *EmAsmConstAsyncMainF =
+ M.getFunction("emscripten_asm_const_async_on_main_thread");
+
+ return Callee == EmAsmConstIntF || Callee == EmAsmConstDoubleF ||
+ Callee == EmAsmConstIntSyncMainF ||
+ Callee == EmAsmConstDoubleSyncMainF || Callee == EmAsmConstAsyncMainF;
+}
+
// Generate testSetjmp function call seqence with preamble and postamble.
// The code this generates is equivalent to the following JavaScript code:
// if (%__THREW__.val != 0 & threwValue != 0) {
@@ -983,6 +1001,12 @@ bool WebAssemblyLowerEmscriptenEHSjLj::r
const Value *Callee = CI->getCalledValue();
if (!canLongjmp(M, Callee))
continue;
+ if (isEmAsmCall(M, Callee))
+ report_fatal_error("Cannot use EM_ASM* alongside setjmp/longjmp in " +
+ F.getName() +
+ ". Please consider using EM_JS, or move the "
+ "EM_ASM into another function.",
+ false);
Value *Threw = nullptr;
BasicBlock *Tail;
More information about the llvm-commits
mailing list