From 67acdea9003e9b00f9c471206acf00a5332e3ac4 Mon Sep 17 00:00:00 2001
From: Justin Lebar <jlebar@google.com>
Date: Sat, 23 Jan 2016 21:12:20 +0000
Subject: [PATCH] [CUDA] Die gracefully when trying to output an LLVM alias.

Summary:
Previously, we would just output "foo = bar" in the assembly, and then
ptxas would choke.  Now we die before emitting any invalid code.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, jhen, tra

Differential Revision: http://reviews.llvm.org/D16490

llvm-svn: 258638
---
 lib/Target/NVPTX/NVPTXAsmPrinter.cpp | 5 +++++
 test/CodeGen/NVPTX/alias.ll          | 7 +++++++
 2 files changed, 12 insertions(+)
 create mode 100644 test/CodeGen/NVPTX/alias.ll

diff --git a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index c842cf86ae4..ebeeedaec69 100644
--- a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -812,6 +812,11 @@ bool NVPTXAsmPrinter::doInitialization(Module &M) {
   const NVPTXTargetMachine &NTM = static_cast<const NVPTXTargetMachine &>(TM);
   const NVPTXSubtarget STI(TT, CPU, FS, NTM);
 
+  if (M.alias_size()) {
+    report_fatal_error("Module has aliases, which NVPTX does not support.");
+    return true; // error
+  }
+
   SmallString<128> Str1;
   raw_svector_ostream OS1(Str1);
 
diff --git a/test/CodeGen/NVPTX/alias.ll b/test/CodeGen/NVPTX/alias.ll
new file mode 100644
index 00000000000..a2785192769
--- /dev/null
+++ b/test/CodeGen/NVPTX/alias.ll
@@ -0,0 +1,7 @@
+; RUN: not llc < %s -march=nvptx -mcpu=sm_20 2>&1 | FileCheck %s
+
+; Check that llc dies gracefully when given an alias.
+
+define i32 @a() { ret i32 0 }
+; CHECK: ERROR: Module has aliases
+@b = internal alias i32 (), i32 ()* @a