Revert "[NFC] Add fragment-getting functions to DbgRecord (llvm#97705)"

This reverts commit f21b62b.

Fails to build.

Author: nikic

llvm/include/llvm/IR/DbgVariableFragmentInfo.h

@@ -21,7 +21,6 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/IR/Constants.h"
-#include "llvm/IR/DbgVariableFragmentInfo.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/PseudoProbe.h"
 #include "llvm/Support/Casting.h"
@@ -2887,7 +2886,29 @@ class DIExpression : public MDNode {
   /// Return whether there is exactly one operator and it is a DW_OP_deref;
   bool isDeref() const;
 
-  using FragmentInfo = DbgVariableFragmentInfo;
+  /// Holds the characteristics of one fragment of a larger variable.
+  struct FragmentInfo {
+    FragmentInfo() = default;
+    FragmentInfo(uint64_t SizeInBits, uint64_t OffsetInBits)
+        : SizeInBits(SizeInBits), OffsetInBits(OffsetInBits) {}
+    uint64_t SizeInBits;
+    uint64_t OffsetInBits;
+    /// Return the index of the first bit of the fragment.
+    uint64_t startInBits() const { return OffsetInBits; }
+    /// Return the index of the bit after the end of the fragment, e.g. for
+    /// fragment offset=16 and size=32 return their sum, 48.
+    uint64_t endInBits() const { return OffsetInBits + SizeInBits; }
+
+    /// Returns a zero-sized fragment if A and B don't intersect.
+    static DIExpression::FragmentInfo intersect(DIExpression::FragmentInfo A,
+                                                DIExpression::FragmentInfo B) {
+      uint64_t StartInBits = std::max(A.OffsetInBits, B.OffsetInBits);
+      uint64_t EndInBits = std::min(A.endInBits(), B.endInBits());
+      if (EndInBits <= StartInBits)
+        return {0, 0};
+      return DIExpression::FragmentInfo(EndInBits - StartInBits, StartInBits);
+    }
+  };
 
   /// Return the number of bits that have an active value, i.e. those that
   /// aren't known to be zero/sign (depending on the type of Var) and which

llvm/include/llvm/IR/DebugInfoMetadata.h

@@ -50,7 +50,6 @@
 #include "llvm/ADT/ilist.h"
 #include "llvm/ADT/ilist_node.h"
 #include "llvm/ADT/iterator.h"
-#include "llvm/IR/DbgVariableFragmentInfo.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/SymbolTableListTraits.h"
@@ -461,17 +460,6 @@ class DbgVariableRecord : public DbgRecord, protected DebugValueUser {
     resetDebugValue(0, NewLocation);
   }
 
-  std::optional<DbgVariableFragmentInfo> getFragment() const;
-  /// Get the FragmentInfo for the variable if it exists, otherwise return a
-  /// FragmentInfo that covers the entire variable if the variable size is
-  /// known, otherwise return a zero-sized fragment.
-  DbgVariableFragmentInfo getFragmentOrEntireVariable() const {
-    if (auto Frag = getFragment())
-      return *Frag; 
-    if (auto Sz = getVariable()->getSizeInBits())
-      return {*Sz, 0};
-    return {0, 0};
-  }
   /// Get the size (in bits) of the variable, or fragment of the variable that
   /// is described.
   std::optional<uint64_t> getFragmentSizeInBits() const;

llvm/include/llvm/IR/DebugProgramInstruction.h

@@ -371,10 +371,6 @@ bool DbgVariableRecord::isKillLocation() const {
          any_of(location_ops(), [](Value *V) { return isa<UndefValue>(V); });
 }
 
-std::optional<DbgVariableFragmentInfo> DbgVariableRecord::getFragment() const {
-  return getExpression()->getFragmentInfo();
-}
-
 std::optional<uint64_t> DbgVariableRecord::getFragmentSizeInBits() const {
   if (auto Fragment = getExpression()->getFragmentInfo())
     return Fragment->SizeInBits;