PNaCl ABI checker: Disallow the GetElementPtr instruction

This instruction is removed by ExpandGetElementPtr.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3343
TEST=test/NaCl/PNaClABI/instructions.ll + PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/14071005

2 files changed, 4 insertions, 1 deletions

diff --git a/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp b/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp
index 55269dc9fe..5e773e9751 100644
--- a/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp
+++ b/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp
@@ -65,6 +65,8 @@ bool PNaClABIVerifyFunctions::runOnFunction(Function &F) {
       switch (BBI->getOpcode()) {
         // Disallowed instructions. Default is to disallow.
         default:
+        // We expand GetElementPtr out into arithmetic.
+        case Instruction::GetElementPtr:
         // indirectbr may interfere with streaming
         case Instruction::IndirectBr:
         // No vector instructions yet
@@ -112,7 +114,6 @@ bool PNaClABIVerifyFunctions::runOnFunction(Function &F) {
         case Instruction::Fence:
         case Instruction::AtomicCmpXchg:
         case Instruction::AtomicRMW:
-        case Instruction::GetElementPtr:
         // Conversion operations
         case Instruction::Trunc:
         case Instruction::ZExt:
diff --git a/test/NaCl/PNaClABI/instructions.ll b/test/NaCl/PNaClABI/instructions.ll
index 3bd95c8e0f..49585b1fca 100644
--- a/test/NaCl/PNaClABI/instructions.ll
+++ b/test/NaCl/PNaClABI/instructions.ll
@@ -71,6 +71,8 @@ define void @memory() {
   fence acq_rel
   %a3 = cmpxchg i32* undef, i32 undef, i32 undef acq_rel
   %a4 = atomicrmw add i32* undef, i32 1 acquire
+; CHECK-NOT: disallowed
+; CHECK: Function memory has disallowed instruction: getelementptr
   %a5 = getelementptr { i32, i32}* undef
   ret void
 }