Reapply "[DLCov] Implement DebugLoc coverage tracking (#107279)"

Reapplied after fixing the config issue that was causing issues following
the previous merge.

This reverts commit fdbf073a86573c9ac4d595fac8e06d252ce1469f.

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 557b57d..dff9a08 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -988,8 +988,10 @@ void Instruction::updateLocationAfterHoist() { dropLocation(); }
 
 void Instruction::dropLocation() {
   const DebugLoc &DL = getDebugLoc();
-  if (!DL)
+  if (!DL) {
+    setDebugLoc(DebugLoc::getDropped());
     return;
+  }
 
   // If this isn't a call, drop the location to allow a location from a
   // preceding instruction to propagate.
@@ -1001,7 +1003,7 @@ void Instruction::dropLocation() {
   }
 
   if (!MayLowerToCall) {
-    setDebugLoc(DebugLoc());
+    setDebugLoc(DebugLoc::getDropped());
     return;
   }
 
@@ -1020,7 +1022,7 @@ void Instruction::dropLocation() {
     //
     // One alternative is to set a line 0 location with the existing scope and
     // inlinedAt info. The location might be sensitive to when inlining occurs.
-    setDebugLoc(DebugLoc());
+    setDebugLoc(DebugLoc::getDropped());
 }
 
 //===----------------------------------------------------------------------===//