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

4 files changed, 4 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h b/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
index 6f30d294f71..6914bbe9a59 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
@@ -43,7 +43,7 @@ public:
     Value(const MDNode *Var, const MDNode *Expr, MachineLocation Loc)
         : Variable(Var), Expression(Expr), EntryKind(E_Location), Loc(Loc) {
       assert(DIVariable(Var).Verify());
-      assert(DIExpression(Expr).Verify());
+      assert(DIExpression(Expr)->isValid());
     }
 
     /// The variable to which this location entry corresponds.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 6e462bf06d0..952da04a4b4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -88,7 +88,8 @@ public:
     : Var(V), Expr(1, E), TheDIE(nullptr), DotDebugLocOffset(~0U),
       MInsn(nullptr), DD(DD) {
     FrameIndex.push_back(FI);
-    assert(Var.Verify() && E.Verify());
+    assert(Var.Verify());
+    assert(!E || E->isValid());
   }
 
   /// Construct a DbgVariable from a DEBUG_VALUE.
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(); }
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index ba33d792cb2..cc5fa690d58 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -3078,15 +3078,11 @@ void DebugInfoVerifier::processCallInst(DebugInfoFinder &Finder,
       case Intrinsic::dbg_declare: {
         auto *DDI = cast<DbgDeclareInst>(&CI);
         Finder.processDeclare(*M, DDI);
-        if (auto E = DDI->getExpression())
-          Assert(DIExpression(E).Verify(), "DIExpression does not Verify!", E);
         break;
       }
       case Intrinsic::dbg_value: {
         auto *DVI = cast<DbgValueInst>(&CI);
         Finder.processValue(*M, DVI);
-        if (auto E = DVI->getExpression())
-          Assert(DIExpression(E).Verify(), "DIExpression does not Verify!", E);
         break;
       }
       default: