4 files changed, 111 insertions, 6 deletions
diff --git a/include/llvm/DebugInfo/DWARF/DWARFContext.h b/include/llvm/DebugInfo/DWARF/DWARFContext.h
index 3c04c6716ea3..b9f3425d5deb 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFContext.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFContext.h
@@ -172,6 +172,9 @@ public:
     return DWOCUs[index].get();
   }
 
+  /// Get a DIE given an exact offset.
+  DWARFDie getDIEForOffset(uint32_t Offset);
+
   const DWARFUnitIndex &getCUIndex();
   DWARFGdbIndex &getGdbIndex();
   const DWARFUnitIndex &getTUIndex();
diff --git a/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h b/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h
index dd0e2648bf30..e21245b97b73 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h
@@ -30,7 +30,7 @@ public:
   struct FileNameEntry {
     FileNameEntry() = default;
 
-    const char *Name = nullptr;
+    StringRef Name = StringRef();
     uint64_t DirIdx = 0;
     uint64_t ModTime = 0;
     uint64_t Length = 0;
@@ -44,6 +44,10 @@ public:
     uint64_t TotalLength;
     /// Version identifier for the statement information format.
     uint16_t Version;
+    /// In v5, size in bytes of an address (or segment offset).
+    uint8_t AddressSize;
+    /// In v5, size in bytes of a segment selector.
+    uint8_t SegSelectorSize;
     /// The number of bytes following the prologue_length field to the beginning
     /// of the first byte of the statement program itself.
     uint64_t PrologueLength;
@@ -63,7 +67,7 @@ public:
     /// The number assigned to the first special opcode.
     uint8_t OpcodeBase;
     std::vector<uint8_t> StandardOpcodeLengths;
-    std::vector<const char *> IncludeDirectories;
+    std::vector<StringRef> IncludeDirectories;
     std::vector<FileNameEntry> FileNames;
 
     bool IsDWARF64;
@@ -100,7 +104,7 @@ public:
     void postAppend();
     void reset(bool DefaultIsStmt);
     void dump(raw_ostream &OS) const;
-
+    static void dumpTableHeader(raw_ostream &OS);
     static bool orderByAddress(const Row &LHS, const Row &RHS) {
       return LHS.Address < RHS.Address;
     }
diff --git a/include/llvm/DebugInfo/DWARF/DWARFUnit.h b/include/llvm/DebugInfo/DWARF/DWARFUnit.h
index e29ba523238c..68e541bac73c 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFUnit.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFUnit.h
@@ -312,9 +312,9 @@ public:
         [](const DWARFDebugInfoEntry &LHS, uint32_t Offset) {
           return LHS.getOffset() < Offset;
         });
-    if (it == DieArray.end())
-      return DWARFDie();
-    return DWARFDie(this, &*it);
+    if (it != DieArray.end() && it->getOffset() == Offset)
+      return DWARFDie(this, &*it);
+    return DWARFDie();
   }
 
   uint32_t getLineTableOffset() const {
diff --git a/include/llvm/DebugInfo/DWARF/DWARFVerifier.h b/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
new file mode 100644
index 000000000000..8e12bcd2c8e2
--- /dev/null
+++ b/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
@@ -0,0 +1,98 @@
+//===- DWARFVerifier.h ----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H
+#define LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H
+
+#include <cstdint>
+#include <map>
+#include <set>
+
+namespace llvm {
+class raw_ostream;
+struct DWARFAttribute;
+class DWARFContext;
+class DWARFDie;
+class DWARFUnit;
+
+/// A class that verifies DWARF debug information given a DWARF Context.
+class DWARFVerifier {
+  raw_ostream &OS;
+  DWARFContext &DCtx;
+  /// A map that tracks all references (converted absolute references) so we
+  /// can verify each reference points to a valid DIE and not an offset that
+  /// lies between to valid DIEs.
+  std::map<uint64_t, std::set<uint32_t>> ReferenceToDIEOffsets;
+  uint32_t NumDebugInfoErrors;
+  uint32_t NumDebugLineErrors;
+
+  /// Verifies the attribute's DWARF attribute and its value.
+  ///
+  /// This function currently checks for:
+  /// - DW_AT_ranges values is a valid .debug_ranges offset
+  /// - DW_AT_stmt_list is a valid .debug_line offset
+  ///
+  /// @param Die          The DWARF DIE that owns the attribute value
+  /// @param AttrValue    The DWARF attribute value to check
+  void verifyDebugInfoAttribute(DWARFDie &Die, DWARFAttribute &AttrValue);
+
+  /// Verifies the attribute's DWARF form.
+  ///
+  /// This function currently checks for:
+  /// - All DW_FORM_ref values that are CU relative have valid CU offsets
+  /// - All DW_FORM_ref_addr values have valid .debug_info offsets
+  /// - All DW_FORM_strp values have valid .debug_str offsets
+  ///
+  /// @param Die          The DWARF DIE that owns the attribute value
+  /// @param AttrValue    The DWARF attribute value to check
+  void verifyDebugInfoForm(DWARFDie &Die, DWARFAttribute &AttrValue);
+
+  /// Verifies the all valid references that were found when iterating through
+  /// all of the DIE attributes.
+  ///
+  /// This function will verify that all references point to DIEs whose DIE
+  /// offset matches. This helps to ensure if a DWARF link phase moved things
+  /// around, that it doesn't create invalid references by failing to relocate
+  /// CU relative and absolute references.
+  void veifyDebugInfoReferences();
+
+  /// Verify the the DW_AT_stmt_list encoding and value and ensure that no
+  /// compile units that have the same DW_AT_stmt_list value.
+  void verifyDebugLineStmtOffsets();
+
+  /// Verify that all of the rows in the line table are valid.
+  ///
+  /// This function currently checks for:
+  /// - addresses within a sequence that decrease in value
+  /// - invalid file indexes
+  void verifyDebugLineRows();
+
+public:
+  DWARFVerifier(raw_ostream &S, DWARFContext &D)
+      : OS(S), DCtx(D), NumDebugInfoErrors(0), NumDebugLineErrors(0) {}
+  /// Verify the information in the .debug_info section.
+  ///
+  /// Any errors are reported to the stream that was this object was
+  /// constructed with.
+  ///
+  /// @return True if the .debug_info verifies successfully, false otherwise.
+  bool handleDebugInfo();
+
+  /// Verify the information in the .debug_line section.
+  ///
+  /// Any errors are reported to the stream that was this object was
+  /// constructed with.
+  ///
+  /// @return True if the .debug_line verifies successfully, false otherwise.
+  bool handleDebugLine();
+};
+
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H