[WebAssembly] Fix allocsize attribute in sjlj lowering

Summary: The allocsize attribute refers to call parameters by index. Thus, when we add the extra parameter in sjlj lowering, we need to increment the referenced paramater in the allocsize attribute to avoid angering the Verifier. Reviewed By: aheejin Differential Revision: https://reviews.llvm.org/D65470 llvm-svn: 367765
llvm · Aug 3, 2019 · 3c805d1 · 3c805d1
1 parent 3daccaa
commit 3c805d1
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Showing 2 changed files with 31 additions and 3 deletions.
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
@@ -432,9 +432,22 @@ Value *WebAssemblyLowerEmscriptenEHSjLj::wrapInvoke(CallOrInvoke *CI) {
   for (unsigned I = 0, E = CI->getNumArgOperands(); I < E; ++I)
     ArgAttributes.push_back(InvokeAL.getParamAttributes(I));
 
+  AttrBuilder FnAttrs(InvokeAL.getFnAttributes());
+  if (FnAttrs.contains(Attribute::AllocSize)) {
+    // The allocsize attribute (if any) referes to parameters by index and needs
+    // to be adjusted.
+    unsigned SizeArg;
+    Optional<unsigned> NEltArg;
+    std::tie(SizeArg, NEltArg) = FnAttrs.getAllocSizeArgs();
+    SizeArg += 1;
+    if (NEltArg.hasValue())
+      NEltArg = NEltArg.getValue() + 1;
+    FnAttrs.addAllocSizeAttr(SizeArg, NEltArg);
+  }
+
   // Reconstruct the AttributesList based on the vector we constructed.
   AttributeList NewCallAL =
-      AttributeList::get(C, InvokeAL.getFnAttributes(),
+      AttributeList::get(C, AttributeSet::get(C, FnAttrs),
                          InvokeAL.getRetAttributes(), ArgAttributes);
   NewCall->setAttributes(NewCallAL);
 

diff --git a/llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll b/llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
@@ -94,7 +94,7 @@ entry:
 }
 
 ; Test a case when a function call is within try-catch, after a setjmp
-define hidden void @exception_and_longjmp() #3 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+define hidden void @exception_and_longjmp() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
 ; CHECK-LABEL: @exception_and_longjmp
 entry:
   %buf = alloca [1 x %struct.__jmp_buf_tag], align 16
@@ -185,7 +185,7 @@ entry:
   call void @longjmp(%struct.__jmp_buf_tag* %arraydecay, i32 5) #1
   unreachable
 ; CHECK: %[[ARRAYDECAY:.*]] = getelementptr inbounds
-; CHECK-NEXT: call void @emscripten_longjmp_jmpbuf(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 5) #1
+; CHECK-NEXT: call void @emscripten_longjmp_jmpbuf(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 5)
 }
 
 ; Test inline asm handling
@@ -203,6 +203,19 @@ entry:
   ret void
 }
 
+; Test that the allocsize attribute is being transformed properly
+declare i8 *@allocator(i32, %struct.__jmp_buf_tag*) #3
+define hidden i8 *@allocsize() {
+; CHECK-LABEL: @allocsize
+entry:
+  %buf = alloca [1 x %struct.__jmp_buf_tag], align 16
+  %arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
+  %call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
+; CHECK: i8* @"__invoke_i8*_i32_%struct.__jmp_buf_tag*"([[ARGS:.*]]) #[[ALLOCSIZE_ATTR:[0-9]+]]
+  %alloc = call i8* @allocator(i32 20, %struct.__jmp_buf_tag* %arraydecay) #3
+  ret i8 *%alloc
+}
+
 declare void @foo()
 ; Function Attrs: returns_twice
 declare i32 @setjmp(%struct.__jmp_buf_tag*) #0
@@ -227,3 +240,5 @@ declare void @free(i8*)
 attributes #0 = { returns_twice }
 attributes #1 = { noreturn }
 attributes #2 = { nounwind }
+attributes #3 = { allocsize(0) }
+; CHECK: attributes #[[ALLOCSIZE_ATTR]] = { allocsize(1) }