CodeGen: Assert that bundle iterators are valid

Add an assertion to the MachineInstrBundleIterator from instr_iterator
that the underlying iterator is valid.  This is possible know that we
can check ilist_node::isSentinel (since r281168), and is consistent with
the constructors from MachineInstr* and MachineInstr&.

Avoiding the new assertion in operator== and operator!= requires four
(!!!!) new overloads each.

(As an aside, I'm strongly in favour of:
- making the conversion from instr_iterator explicit;
- making the conversion from pointer explicit;
- making the conversion from reference explicit; and
- removing all the extra overloads of operator== and operator!= except
  const_instr_iterator.

I'm not signing up for that at this point, but being clear about when
something is an MachineInstr-iterator (possibly instr_end()) vs
MachineInstr-bundle-iterator (possibly end()) vs MachineInstr* (possibly
nullptr) vs MachineInstr& (known valid) would surely make code
cleaner... and it would remove a ton of boilerplate from
MachineInstrBundleIterator operators.)

llvm-svn: 281170

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/unittests/CodeGen/MachineInstrBundleIteratorTest.cpp b/llvm/unittests/CodeGen/MachineInstrBundleIteratorTest.cpp
index 738d07d06a6..ca61fcbe59f 100644
--- a/llvm/unittests/CodeGen/MachineInstrBundleIteratorTest.cpp
+++ b/llvm/unittests/CodeGen/MachineInstrBundleIteratorTest.cpp
@@ -74,6 +74,14 @@ TEST(MachineInstrBundleIteratorTest, CompareToBundledMI) {
   ASSERT_FALSE(CI == &MBI);
   ASSERT_FALSE(CI == CMBI);
   ASSERT_FALSE(CI == &CMBI);
+  ASSERT_FALSE(MBI.getIterator() == I);
+  ASSERT_FALSE(CMBI.getIterator() == I);
+  ASSERT_FALSE(I == MBI.getIterator());
+  ASSERT_FALSE(I == CMBI.getIterator());
+  ASSERT_FALSE(MBI.getIterator() == CI);
+  ASSERT_FALSE(CMBI.getIterator() == CI);
+  ASSERT_FALSE(CI == MBI.getIterator());
+  ASSERT_FALSE(CI == CMBI.getIterator());
   ASSERT_TRUE(MBI != I);
   ASSERT_TRUE(&MBI != I);
   ASSERT_TRUE(CMBI != I);
@@ -90,6 +98,14 @@ TEST(MachineInstrBundleIteratorTest, CompareToBundledMI) {
   ASSERT_TRUE(CI != &MBI);
   ASSERT_TRUE(CI != CMBI);
   ASSERT_TRUE(CI != &CMBI);
+  ASSERT_TRUE(MBI.getIterator() != I);
+  ASSERT_TRUE(CMBI.getIterator() != I);
+  ASSERT_TRUE(I != MBI.getIterator());
+  ASSERT_TRUE(I != CMBI.getIterator());
+  ASSERT_TRUE(MBI.getIterator() != CI);
+  ASSERT_TRUE(CMBI.getIterator() != CI);
+  ASSERT_TRUE(CI != MBI.getIterator());
+  ASSERT_TRUE(CI != CMBI.getIterator());
 }
 
 } // end namespace