[llvm] r370176 - [LLVM-C] Fix ByVal Attribute crashing

[Hans Wennborg via llvm-commits]

Author: hans
Date: Wed Aug 28 02:21:56 2019
New Revision: 370176

URL: http://llvm.org/viewvc/llvm-project?rev=370176&view=rev
Log:
[LLVM-C] Fix ByVal Attribute crashing

With the introduction of the typed byval attribute change there was no
way that the LLVM-C API could create the correct class Attribute. If a
program that uses the C API creates a ByVal attribute and annotates a
function with that attribute LLVM will crash when it assembles or write
that module containing the function out as bitcode.

This change is a minimal fix to at least allow code to work, this is
because the byval change is on the 9.0 and I don't want to introduce new
LLVM-C API this late in the release cycle.

By Jakob Bornecrantz!

Differential revision: https://reviews.llvm.org/D66144

Modified:
    llvm/trunk/lib/IR/Core.cpp

Modified: llvm/trunk/lib/IR/Core.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Core.cpp?rev=370176&r1=370175&r2=370176&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Core.cpp (original)
+++ llvm/trunk/lib/IR/Core.cpp Wed Aug 28 02:21:56 2019
@@ -140,7 +140,16 @@ unsigned LLVMGetLastEnumAttributeKind(vo
 
 LLVMAttributeRef LLVMCreateEnumAttribute(LLVMContextRef C, unsigned KindID,
                                          uint64_t Val) {
-  return wrap(Attribute::get(*unwrap(C), (Attribute::AttrKind)KindID, Val));
+  auto &Ctx = *unwrap(C);
+  auto AttrKind = (Attribute::AttrKind)KindID;
+
+  if (AttrKind == Attribute::AttrKind::ByVal) {
+    // After r362128, byval attributes need to have a type attribute. Provide a
+    // NULL one until a proper API is added for this.
+    return wrap(Attribute::getWithByValType(Ctx, NULL));
+  } else {
+    return wrap(Attribute::get(Ctx, AttrKind, Val));
+  }
 }
 
 unsigned LLVMGetEnumAttributeKind(LLVMAttributeRef A) {