IR: Take advantage of -verify checks for MDExpression

Now that we check `MDExpression` during `-verify` (r232299), make
the `DIExpression` wrapper more strict:

  - remove redundant checks in `DebugInfoVerifier`,
  - overload `get()` to `cast_or_null<MDExpression>` (superseding
    `getRaw()`),
  - stop checking for null in any accessor, and
  - remove `DIExpression::Verify()` entirely in favour of
    `MDExpression::isValid()`.

There is still some logic in this class, mostly to do with high-level
iterators; I'll defer cleaning up those until the rest of the wrappers
are similarly strict.

llvm-svn: 232412

1 files changed, 1 insertions, 7 deletions

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 148fa2101c0..3c7cf9e1b8d 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -92,7 +92,7 @@ bool DIDescriptor::Verify() const {
           DIObjCProperty(DbgNode).Verify() ||
           DITemplateTypeParameter(DbgNode).Verify() ||
           DITemplateValueParameter(DbgNode).Verify() ||
-          DIImportedEntity(DbgNode).Verify() || DIExpression(DbgNode).Verify());
+          DIImportedEntity(DbgNode).Verify());
 }
 
 static Metadata *getField(const MDNode *DbgNode, unsigned Elt) {
@@ -402,12 +402,6 @@ bool DIVariable::Verify() const {
   return isTypeRef(N->getType());
 }
 
-bool DIExpression::Verify() const {
-  // FIXME: This should return false if it's null!
-  auto *N = getRaw();
-  return !N || N->isValid();
-}
-
 bool DILocation::Verify() const { return getRaw(); }
 bool DINameSpace::Verify() const { return getRaw(); }
 bool DIFile::Verify() const { return getRaw(); }