1 files changed, 184 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h b/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
new file mode 100644
index 000000000000..17e39b3d3268
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugLocEntry.h
@@ -0,0 +1,184 @@
+//===-- llvm/CodeGen/DebugLocEntry.h - Entry in debug_loc list -*- C++ -*--===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCENTRY_H
+
+#include "DebugLocStream.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MachineLocation.h"
+#include "llvm/Support/Debug.h"
+
+namespace llvm {
+class AsmPrinter;
+
+/// A single location or constant.
+class DbgValueLoc {
+  /// Any complex address location expression for this DbgValueLoc.
+  const DIExpression *Expression;
+
+  /// Type of entry that this represents.
+  enum EntryType { E_Location, E_Integer, E_ConstantFP, E_ConstantInt };
+  enum EntryType EntryKind;
+
+  /// Either a constant,
+  union {
+    int64_t Int;
+    const ConstantFP *CFP;
+    const ConstantInt *CIP;
+  } Constant;
+
+  /// Or a location in the machine frame.
+  MachineLocation Loc;
+
+public:
+  DbgValueLoc(const DIExpression *Expr, int64_t i)
+      : Expression(Expr), EntryKind(E_Integer) {
+    Constant.Int = i;
+  }
+  DbgValueLoc(const DIExpression *Expr, const ConstantFP *CFP)
+      : Expression(Expr), EntryKind(E_ConstantFP) {
+    Constant.CFP = CFP;
+  }
+  DbgValueLoc(const DIExpression *Expr, const ConstantInt *CIP)
+      : Expression(Expr), EntryKind(E_ConstantInt) {
+    Constant.CIP = CIP;
+  }
+  DbgValueLoc(const DIExpression *Expr, MachineLocation Loc)
+      : Expression(Expr), EntryKind(E_Location), Loc(Loc) {
+    assert(cast<DIExpression>(Expr)->isValid());
+  }
+
+  bool isLocation() const { return EntryKind == E_Location; }
+  bool isInt() const { return EntryKind == E_Integer; }
+  bool isConstantFP() const { return EntryKind == E_ConstantFP; }
+  bool isConstantInt() const { return EntryKind == E_ConstantInt; }
+  int64_t getInt() const { return Constant.Int; }
+  const ConstantFP *getConstantFP() const { return Constant.CFP; }
+  const ConstantInt *getConstantInt() const { return Constant.CIP; }
+  MachineLocation getLoc() const { return Loc; }
+  bool isFragment() const { return getExpression()->isFragment(); }
+  bool isEntryVal() const { return getExpression()->isEntryValue(); }
+  const DIExpression *getExpression() const { return Expression; }
+  friend bool operator==(const DbgValueLoc &, const DbgValueLoc &);
+  friend bool operator<(const DbgValueLoc &, const DbgValueLoc &);
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+  LLVM_DUMP_METHOD void dump() const {
+    if (isLocation()) {
+      llvm::dbgs() << "Loc = { reg=" << Loc.getReg() << " ";
+      if (Loc.isIndirect())
+        llvm::dbgs() << "+0";
+      llvm::dbgs() << "} ";
+    } else if (isConstantInt())
+      Constant.CIP->dump();
+    else if (isConstantFP())
+      Constant.CFP->dump();
+    if (Expression)
+      Expression->dump();
+  }
+#endif
+};
+
+/// This struct describes location entries emitted in the .debug_loc
+/// section.
+class DebugLocEntry {
+  /// Begin and end symbols for the address range that this location is valid.
+  const MCSymbol *Begin;
+  const MCSymbol *End;
+
+  /// A nonempty list of locations/constants belonging to this entry,
+  /// sorted by offset.
+  SmallVector<DbgValueLoc, 1> Values;
+
+public:
+  /// Create a location list entry for the range [\p Begin, \p End).
+  ///
+  /// \param Vals One or more values describing (parts of) the variable.
+  DebugLocEntry(const MCSymbol *Begin, const MCSymbol *End,
+                ArrayRef<DbgValueLoc> Vals)
+      : Begin(Begin), End(End) {
+    addValues(Vals);
+  }
+
+  /// Attempt to merge this DebugLocEntry with Next and return
+  /// true if the merge was successful. Entries can be merged if they
+  /// share the same Loc/Constant and if Next immediately follows this
+  /// Entry.
+  bool MergeRanges(const DebugLocEntry &Next) {
+    // If this and Next are describing the same variable, merge them.
+    if ((End == Next.Begin && Values == Next.Values)) {
+      End = Next.End;
+      return true;
+    }
+    return false;
+  }
+
+  const MCSymbol *getBeginSym() const { return Begin; }
+  const MCSymbol *getEndSym() const { return End; }
+  ArrayRef<DbgValueLoc> getValues() const { return Values; }
+  void addValues(ArrayRef<DbgValueLoc> Vals) {
+    Values.append(Vals.begin(), Vals.end());
+    sortUniqueValues();
+    assert((Values.size() == 1 || all_of(Values, [](DbgValueLoc V) {
+              return V.isFragment();
+            })) && "must either have a single value or multiple pieces");
+  }
+
+  // Sort the pieces by offset.
+  // Remove any duplicate entries by dropping all but the first.
+  void sortUniqueValues() {
+    llvm::sort(Values);
+    Values.erase(std::unique(Values.begin(), Values.end(),
+                             [](const DbgValueLoc &A, const DbgValueLoc &B) {
+                               return A.getExpression() == B.getExpression();
+                             }),
+                 Values.end());
+  }
+
+  /// Lower this entry into a DWARF expression.
+  void finalize(const AsmPrinter &AP,
+                DebugLocStream::ListBuilder &List,
+                const DIBasicType *BT,
+                DwarfCompileUnit &TheCU);
+};
+
+/// Compare two DbgValueLocs for equality.
+inline bool operator==(const DbgValueLoc &A,
+                       const DbgValueLoc &B) {
+  if (A.EntryKind != B.EntryKind)
+    return false;
+
+  if (A.Expression != B.Expression)
+    return false;
+
+  switch (A.EntryKind) {
+  case DbgValueLoc::E_Location:
+    return A.Loc == B.Loc;
+  case DbgValueLoc::E_Integer:
+    return A.Constant.Int == B.Constant.Int;
+  case DbgValueLoc::E_ConstantFP:
+    return A.Constant.CFP == B.Constant.CFP;
+  case DbgValueLoc::E_ConstantInt:
+    return A.Constant.CIP == B.Constant.CIP;
+  }
+  llvm_unreachable("unhandled EntryKind");
+}
+
+/// Compare two fragments based on their offset.
+inline bool operator<(const DbgValueLoc &A,
+                      const DbgValueLoc &B) {
+  return A.getExpression()->getFragmentInfo()->OffsetInBits <
+         B.getExpression()->getFragmentInfo()->OffsetInBits;
+}
+
+}
+
+#endif