commit f8ca9784172f263173119f09586815d13113b546
author Justin Bogner <mail@justinbogner.com> Thu May 14 06:47:02 2015 +0000
committer Justin Bogner <mail@justinbogner.com> Thu May 14 06:47:02 2015 +0000
tree de5c9b803934373bace4fee989296327574b894c
parent bed1965111fc29929e8b282c489e05c857610fb9

TableGen: Avoid undefined behaviour by doing this shift in int64

Found by ubsan. This was taking a bool and left shifting by 32 - the
result is 64 bit, so we should really do the math in a type it fits
in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237345 91177308-0d34-0410-b5e6-96231b3b80d8

lib/TableGen/Record.cpp

diff --git a/lib/TableGen/Record.cpp b/lib/TableGen/Record.cpp
index 7229b8c..1b5a902 100644
--- a/lib/TableGen/Record.cpp
+++ b/lib/TableGen/Record.cpp
@@ -230,7 +230,7 @@
   int64_t Result = 0;
   for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i)
     if (BitInit *Bit = dyn_cast<BitInit>(BI->getBit(i)))
-      Result |= Bit->getValue() << i;
+      Result |= static_cast<int64_t>(Bit->getValue()) << i;
     else
       return nullptr;
   return IntInit::get(Result);