DebugInfo: Assert dbg.declare/value insts are valid

Remove early returns for when `getVariable()` is null, and just assert
that it never happens.  The Verifier already confirms that there's a
valid variable on these intrinsics, so we should assume the debug info
isn't broken.  I also updated a check for a `!dbg` attachment, which the
Verifier similarly guarantees.

llvm-svn: 235400

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index bb40326ba2d..b7882329955 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -202,8 +202,9 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
       // during the initial isel pass through the IR so that it is done
       // in a predictable order.
       if (const DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(I)) {
-        DIVariable DIVar = DI->getVariable();
-        if (MMI.hasDebugInfo() && DIVar && DI->getDebugLoc()) {
+        assert(DI->getVariable() && "Missing variable");
+        assert(DI->getDebugLoc() && "Missing location");
+        if (MMI.hasDebugInfo()) {
           // Don't handle byval struct arguments or VLAs, for example.
           // Non-byval arguments are handled here (they refer to the stack
           // temporary alloca at this point).