[MIPS] Don't crash on unsized extern types with -mgpopt

Summary: This fixes an assertion when building the FreeBSD MIPS64 kernel.

Reviewers: atanasyan, sdardis, emaste

Reviewed By: sdardis

Subscribers: krytarowski, llvm-commits

Differential Revision: https://reviews.llvm.org/D42571

llvm-svn: 323536

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp b/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
index 9db6b7b1bcd..f767c832198 100644
--- a/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
+++ b/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
@@ -136,6 +136,13 @@ IsGlobalInSmallSectionImpl(const GlobalObject *GO,
     return false;
 
   Type *Ty = GVA->getValueType();
+
+  // It is possible that the type of the global is unsized, i.e. a declaration
+  // of a extern struct. In this case don't presume it is in the small data
+  // section. This happens e.g. when building the FreeBSD kernel.
+  if (!Ty->isSized())
+    return false;
+
   return IsInSmallSection(
       GVA->getParent()->getDataLayout().getTypeAllocSize(Ty));
 }