[Verifier] Check byval/etc type when comparing ABI attributes

[nikic]

Summary

For musttail calls, ABI attributes between the function and the musttail call must match. The current check discards the type of type attribute like byval, which means that it will consider byval(i32) and byval(i64) (or similar) as compatible.

I assume this is a leftover from before these attributes had a type argument. Ran into this while trying to tighten an assertion in AttrBuilder.

[rnk]

lgtm

Yes, attempting to actually execute such a tail call would probably crash.

llvm/lib/IR/Verifier.cpp

 static AttrBuilder getParameterABIAttributes(int I, AttributeList Attrs) {
   static const Attribute::AttrKind ABIAttrs[] = {
       Attribute::StructRet,  Attribute::ByVal,          Attribute::InAlloca,
       Attribute::InReg,      Attribute::StackAlignment, Attribute::SwiftSelf,
       Attribute::SwiftAsync, Attribute::SwiftError,     Attribute::Preallocated,
       Attribute::ByRef};
   AttrBuilder Copy;
   for (auto AK : ABIAttrs) {
-    if (Attrs.hasParamAttribute(I, AK))
-      Copy.addAttribute(AK);
+    Attribute Attr = Attrs.getParamAttributes(I).getAttribute(AK);
+    if (Attr.isValid())
+      Copy.addAttribute(Attr);
   }
 
   // `align` is ABI-affecting only in combination with `byval` or `byref`.
   if (Attrs.hasParamAttribute(I, Attribute::Alignment) &&
       (Attrs.hasParamAttribute(I, Attribute::ByVal) ||
        Attrs.hasParamAttribute(I, Attribute::ByRef)))
     Copy.addAlignmentAttr(Attrs.getParamAlignment(I));
   return Copy;

llvm/test/Verifier/musttail-invalid.ll

 
 declare void @mismatched_byval_callee({ i32 }*)
 define void @mismatched_byval({ i32 }* byval({ i32 }) %a) {
 ; CHECK: mismatched ABI impacting function attributes
   musttail call void @mismatched_byval_callee({ i32 }* %a)
   ret void
 }
 
+declare void @mismatched_byval_callee2(ptr byval(i32))
+define void @mismatched_byval2(ptr byval(i64) %a) {
+; CHECK: mismatched ABI impacting function attributes
+  musttail call void @mismatched_byval_callee2(ptr byval(i32) %a)
+  ret void
+}
+
 declare void @mismatched_inreg_callee(i32 inreg)
 define void @mismatched_inreg(i32 %a) {
 ; CHECK: mismatched ABI impacting function attributes
   musttail call void @mismatched_inreg_callee(i32 inreg %a)
   ret void
 }
 
 declare void @mismatched_sret_callee(i32* sret(i32))