Reapply "[NFC][DebugInfo][DWARF] Create new low-level dwarf library (#… (#145959) (#146112)

Reapply "[NFC][DebugInfo][DWARF] Create new low-level dwarf library (#…
(#145959)
    
This reapplies cbf781f0bdf2f680abbe784faedeefd6f84c246e, with fixes for
the shared-library build and the unconventional sanitizer-runtime build.

Original Description:

This is the culmination of a series of changes described in [1].
    
Although somewhat large by line count, it is almost entirely mechanical,
creating a new library in DebugInfo/DWARF/LowLevel. This new library has
very minimal dependencies, allowing it to be used from more places than
the normal DebugInfo/DWARF library--in particular from MC.
    
1.
https://discourse.llvm.org/t/rfc-debuginfo-dwarf-refactor-into-to-lower-and-higher-level-libraries/86665/2

bolt/include/bolt/Core/DIEBuilder.h

@@ -20,8 +20,8 @@
 #include "llvm/CodeGen/DIE.h"
 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Allocator.h"
 
 #include <list>

bolt/lib/Core/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(LLVM_LINK_COMPONENTS
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   Demangle
   MC
   MCDisassembler

bolt/lib/Core/DIEBuilder.cpp

@@ -14,11 +14,11 @@
 #include "llvm/CodeGen/DIE.h"
 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"

bolt/lib/Core/DebugNames.cpp

@@ -8,8 +8,8 @@
 
 #include "bolt/Core/DebugNames.h"
 #include "bolt/Core/BinaryContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/LEB128.h"
 #include <cstdint>

bolt/lib/Rewrite/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(LLVM_LINK_COMPONENTS
   Core
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   JITLink
   MC
   Object

bolt/lib/Rewrite/DWARFRewriter.cpp

@@ -24,10 +24,10 @@
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCObjectWriter.h"

compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh

@@ -174,6 +174,7 @@ $LINK $LIBCXX_ARCHIVE_DIR/libc++.a \
       $LLVM_BUILD/lib/libLLVMObject.a \
       $LLVM_BUILD/lib/libLLVMBinaryFormat.a \
       $LLVM_BUILD/lib/libLLVMDebugInfoDWARF.a \
+      $LLVM_BUILD/lib/libLLVMDebugInfoDWARFLowLevel.a \
       $LLVM_BUILD/lib/libLLVMDebugInfoGSYM.a \
       $LLVM_BUILD/lib/libLLVMSupport.a \
       $LLVM_BUILD/lib/libLLVMDebugInfoPDB.a \

lldb/source/Expression/DWARFExpression.cpp

@@ -36,7 +36,8 @@
 #include "lldb/Target/StackID.h"
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 
 using namespace lldb;
 using namespace lldb_private;
@@ -81,7 +82,7 @@ void DWARFExpression::DumpLocation(Stream *s, lldb::DescriptionLevel level,
   llvm::DIDumpOptions DumpOpts;
   DumpOpts.GetNameForDWARFReg = GetRegName;
   llvm::DWARFExpression E(m_data.GetAsLLVM(), m_data.GetAddressByteSize());
-  llvm::DWARFExpressionPrinter::print(&E, s->AsRawOstream(), DumpOpts, nullptr);
+  llvm::printDwarfExpression(&E, s->AsRawOstream(), DumpOpts, nullptr);
 }
 
 RegisterKind DWARFExpression::GetRegisterKind() const { return m_reg_kind; }

lldb/source/Symbol/UnwindPlan.cpp

@@ -17,7 +17,8 @@
 #include "lldb/Utility/Log.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/DebugInfo/DIContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include <optional>
 
 using namespace lldb;
@@ -89,8 +90,7 @@ static void DumpDWARFExpr(Stream &s, llvm::ArrayRef<uint8_t> expr, Thread *threa
                              order_and_width->second);
     llvm::DWARFExpression E(data, order_and_width->second,
                             llvm::dwarf::DWARF32);
-    llvm::DWARFExpressionPrinter::print(&E, s.AsRawOstream(),
+    printDwarfExpression(&E, s.AsRawOstream(), llvm::DIDumpOptions(), nullptr);
-                                        llvm::DIDumpOptions(), nullptr);
   } else
     s.PutCString("dwarf-expr");
 }

lldb/unittests/Symbol/PostfixExpressionTest.cpp

@@ -11,7 +11,8 @@
 #include "lldb/Utility/StreamString.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/DebugInfo/DIContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/raw_ostream.h"
 #include "gmock/gmock.h"
@@ -160,7 +161,7 @@ static std::string ParseAndGenerateDWARF(llvm::StringRef expr) {
   std::string result;
   llvm::raw_string_ostream os(result);
   llvm::DWARFExpression E(extractor, addr_size, llvm::dwarf::DWARF32);
-  llvm::DWARFExpressionPrinter::print(&E, os, llvm::DIDumpOptions(), nullptr);
+  llvm::printDwarfExpression(&E, os, llvm::DIDumpOptions(), nullptr);
   return result;
 }
 

lldb/unittests/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpressionTests.cpp

@@ -16,7 +16,8 @@
 #include "lldb/Utility/StreamBuffer.h"
 #include "lldb/Utility/StreamString.h"
 #include "llvm/DebugInfo/DIContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 
 using namespace lldb;
 using namespace lldb_private;
@@ -40,7 +41,7 @@ CheckValidProgramTranslation(llvm::StringRef fpo_program,
   std::string result;
   llvm::raw_string_ostream os(result);
   llvm::DWARFExpression E(extractor, /*AddressSize=*/4, llvm::dwarf::DWARF32);
-  llvm::DWARFExpressionPrinter::print(&E, os, llvm::DIDumpOptions(), nullptr);
+  llvm::printDwarfExpression(&E, os, llvm::DIDumpOptions(), nullptr);
 
   // actual check
   ASSERT_EQ(expected_dwarf_expression, result);

llvm/include/llvm/DWARFLinker/AddressesMap.h

@@ -12,8 +12,8 @@
 #include "llvm/ADT/AddressRanges.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include <cstdint>
 
 namespace llvm {

llvm/include/llvm/DWARFLinker/Classic/DWARFLinker.h

@@ -20,7 +20,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Compiler.h"
 #include <map>
 

llvm/include/llvm/DWARFLinker/DWARFLinkerBase.h

@@ -16,7 +16,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Compiler.h"
 #include <map>
 namespace llvm {

llvm/include/llvm/DebugInfo/DWARF/DWARFCFIPrinter.h

@@ -9,7 +9,7 @@
 #ifndef LLVM_DEBUGINFO_DWARF_DWARFCFIPRINTER_H
 #define LLVM_DEBUGINFO_DWARF_DWARFCFIPRINTER_H
 
-#include "llvm/DebugInfo/DWARF/DWARFCFIProgram.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.h"
 #include "llvm/Support/Compiler.h"
 
 namespace llvm {

llvm/include/llvm/DebugInfo/DWARF/DWARFDataExtractor.h

@@ -10,10 +10,10 @@
 #define LLVM_DEBUGINFO_DWARF_DWARFDATAEXTRACTOR_H
 
 #include "llvm/BinaryFormat/Dwarf.h"
-#include "llvm/DebugInfo/DWARF/DWARFDataExtractorSimple.h"
 #include "llvm/DebugInfo/DWARF/DWARFObject.h"
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFDataExtractorSimple.h"
 #include "llvm/Support/Compiler.h"
 
 namespace llvm {

llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h

@@ -12,8 +12,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/iterator.h"
-#include "llvm/DebugInfo/DWARF/DWARFCFIProgram.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Error.h"
 #include "llvm/TargetParser/Triple.h"

llvm/include/llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h

@@ -0,0 +1,66 @@
+//===--- DWARFExpressionPRinter.h - DWARF Expression Printing ---*- 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_DEBUGINFO_DWARF_DWARFEXPRESSIONPRINTER_H
+#define LLVM_DEBUGINFO_DWARF_DWARFEXPRESSIONPRINTER_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+
+// This functionality is separated from the main data structure so that nothing
+// in DWARFExpression.cpp needs build-time dependencies on DWARFUnit or other
+// higher-level Dwarf structures. This approach creates better layering and
+// allows DWARFExpression to be used from code which can't have dependencies on
+// those higher-level structures.
+
+class DWARFUnit;
+struct DIDumpOptions;
+class raw_ostream;
+
+/// Print a Dwarf expression/
+/// \param E to be printed
+/// \param OS to this stream
+/// \param GetNameForDWARFReg callback to return dwarf register name
+LLVM_ABI void printDwarfExpression(const DWARFExpression *E, raw_ostream &OS,
+                                   DIDumpOptions DumpOpts, DWARFUnit *U,
+                                   bool IsEH = false);
+
+/// Print the expression in a format intended to be compact and useful to a
+/// user, but not perfectly unambiguous, or capable of representing every
+/// valid DWARF expression. Returns true if the expression was sucessfully
+/// printed.
+///
+/// \param E to be printed
+/// \param OS to this stream
+/// \param GetNameForDWARFReg callback to return dwarf register name
+///
+/// \returns true if the expression was successfully printed
+LLVM_ABI bool printDwarfExpressionCompact(
+    const DWARFExpression *E, raw_ostream &OS,
+    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg =
+        nullptr);
+
+/// Pretty print a register opcode and operands.
+/// \param U within the context of this Dwarf unit, if any.
+/// \param OS to this stream
+/// \param DumpOpts with these options
+/// \param Opcode to print
+/// \param Operands to the opcode
+///
+/// returns true if the Op was successfully printed
+LLVM_ABI bool prettyPrintRegisterOp(DWARFUnit *U, raw_ostream &OS,
+                                    DIDumpOptions DumpOpts, uint8_t Opcode,
+                                    ArrayRef<uint64_t> Operands);
+
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_DWARF_DWARFEXPRESSIONPRINTER_H

llvm/include/llvm/DebugInfo/DWARF/DWARFVerifier.h

@@ -14,8 +14,8 @@
 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
 #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Compiler.h"
 #include <cstdint>
 #include <map>

llvm/include/llvm/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.h

@@ -12,8 +12,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/iterator.h"
-#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFDataExtractorSimple.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Error.h"
 #include "llvm/TargetParser/Triple.h"
@@ -78,8 +78,150 @@ public:
   /// starting at *Offset and ending at EndOffset. *Offset is updated
   /// to EndOffset upon successful parsing, or indicates the offset
   /// where a problem occurred in case an error is returned.
-  LLVM_ABI Error parse(DWARFDataExtractor Data, uint64_t *Offset,
+  template <typename T>
-                       uint64_t EndOffset);
+  LLVM_ABI Error parse(DWARFDataExtractorBase<T> &Data, uint64_t *Offset,
+                       uint64_t EndOffset) {
+    // See DWARF standard v3, section 7.23
+    const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0;
+    const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f;
+
+    DataExtractor::Cursor C(*Offset);
+    while (C && C.tell() < EndOffset) {
+      uint8_t Opcode = Data.getRelocatedValue(C, 1);
+      if (!C)
+        break;
+
+      // Some instructions have a primary opcode encoded in the top bits.
+      if (uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK) {
+        // If it's a primary opcode, the first operand is encoded in the
+        // bottom bits of the opcode itself.
+        uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK;
+        switch (Primary) {
+        case DW_CFA_advance_loc:
+        case DW_CFA_restore:
+          addInstruction(Primary, Op1);
+          break;
+        case DW_CFA_offset:
+          addInstruction(Primary, Op1, Data.getULEB128(C));
+          break;
+        default:
+          llvm_unreachable("invalid primary CFI opcode");
+        }
+        continue;
+      }
+
+      // Extended opcode - its value is Opcode itself.
+      switch (Opcode) {
+      default:
+        return createStringError(errc::illegal_byte_sequence,
+                                 "invalid extended CFI opcode 0x%" PRIx8,
+                                 Opcode);
+      case DW_CFA_nop:
+      case DW_CFA_remember_state:
+      case DW_CFA_restore_state:
+      case DW_CFA_GNU_window_save:
+      case DW_CFA_AARCH64_negate_ra_state_with_pc:
+        // No operands
+        addInstruction(Opcode);
+        break;
+      case DW_CFA_set_loc:
+        // Operands: Address
+        addInstruction(Opcode, Data.getRelocatedAddress(C));
+        break;
+      case DW_CFA_advance_loc1:
+        // Operands: 1-byte delta
+        addInstruction(Opcode, Data.getRelocatedValue(C, 1));
+        break;
+      case DW_CFA_advance_loc2:
+        // Operands: 2-byte delta
+        addInstruction(Opcode, Data.getRelocatedValue(C, 2));
+        break;
+      case DW_CFA_advance_loc4:
+        // Operands: 4-byte delta
+        addInstruction(Opcode, Data.getRelocatedValue(C, 4));
+        break;
+      case DW_CFA_restore_extended:
+      case DW_CFA_undefined:
+      case DW_CFA_same_value:
+      case DW_CFA_def_cfa_register:
+      case DW_CFA_def_cfa_offset:
+      case DW_CFA_GNU_args_size:
+        // Operands: ULEB128
+        addInstruction(Opcode, Data.getULEB128(C));
+        break;
+      case DW_CFA_def_cfa_offset_sf:
+        // Operands: SLEB128
+        addInstruction(Opcode, Data.getSLEB128(C));
+        break;
+      case DW_CFA_LLVM_def_aspace_cfa:
+      case DW_CFA_LLVM_def_aspace_cfa_sf: {
+        auto RegNum = Data.getULEB128(C);
+        auto CfaOffset = Opcode == DW_CFA_LLVM_def_aspace_cfa
+                             ? Data.getULEB128(C)
+                             : Data.getSLEB128(C);
+        auto AddressSpace = Data.getULEB128(C);
+        addInstruction(Opcode, RegNum, CfaOffset, AddressSpace);
+        break;
+      }
+      case DW_CFA_offset_extended:
+      case DW_CFA_register:
+      case DW_CFA_def_cfa:
+      case DW_CFA_val_offset: {
+        // Operands: ULEB128, ULEB128
+        // Note: We can not embed getULEB128 directly into function
+        // argument list. getULEB128 changes Offset and order of evaluation
+        // for arguments is unspecified.
+        uint64_t op1 = Data.getULEB128(C);
+        uint64_t op2 = Data.getULEB128(C);
+        addInstruction(Opcode, op1, op2);
+        break;
+      }
+      case DW_CFA_offset_extended_sf:
+      case DW_CFA_def_cfa_sf:
+      case DW_CFA_val_offset_sf: {
+        // Operands: ULEB128, SLEB128
+        // Note: see comment for the previous case
+        uint64_t op1 = Data.getULEB128(C);
+        uint64_t op2 = (uint64_t)Data.getSLEB128(C);
+        addInstruction(Opcode, op1, op2);
+        break;
+      }
+      case DW_CFA_def_cfa_expression: {
+        uint64_t ExprLength = Data.getULEB128(C);
+        addInstruction(Opcode, 0);
+        StringRef Expression = Data.getBytes(C, ExprLength);
+
+        DataExtractor Extractor(Expression, Data.isLittleEndian(),
+                                Data.getAddressSize());
+        // Note. We do not pass the DWARF format to DWARFExpression, because
+        // DW_OP_call_ref, the only operation which depends on the format, is
+        // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5.
+        Instructions.back().Expression =
+            DWARFExpression(Extractor, Data.getAddressSize());
+        break;
+      }
+      case DW_CFA_expression:
+      case DW_CFA_val_expression: {
+        uint64_t RegNum = Data.getULEB128(C);
+        addInstruction(Opcode, RegNum, 0);
+
+        uint64_t BlockLength = Data.getULEB128(C);
+        StringRef Expression = Data.getBytes(C, BlockLength);
+        DataExtractor Extractor(Expression, Data.isLittleEndian(),
+                                Data.getAddressSize());
+        // Note. We do not pass the DWARF format to DWARFExpression, because
+        // DW_OP_call_ref, the only operation which depends on the format, is
+        // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5.
+        Instructions.back().Expression =
+            DWARFExpression(Extractor, Data.getAddressSize());
+        break;
+      }
+      }
+    }
+
+    *Offset = C.tell();
+    return C.takeError();
+  }
 
   void addInstruction(const Instruction &I) { Instructions.push_back(I); }
 

llvm/include/llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h

@@ -77,7 +77,6 @@ public:
 
   private:
     friend class DWARFExpression::iterator;
-    friend class DWARFExpressionPrinter;
     friend class DWARFVerifier;
 
     uint8_t Opcode; ///< The Op Opcode, DW_OP_<something>.
@@ -156,7 +155,6 @@ public:
 
   StringRef getData() const { return Data.getData(); }
 
-  friend class DWARFExpressionPrinter;
   friend class DWARFVerifier;
 
 private:
@@ -170,65 +168,6 @@ inline bool operator==(const DWARFExpression::iterator &LHS,
   return LHS.Expr == RHS.Expr && LHS.Offset == RHS.Offset;
 }
 
-// This functionality is separated from the main data structure so that nothing
-// in DWARFExpression.cpp needs build-time dependencies on DWARFUnit or other
-// higher-level Dwarf structures. This approach creates better layering and
-// allows DWARFExpression to be used from code which can't have dependencies on
-// those higher-level structures.
-
-class DWARFUnit;
-struct DIDumpOptions;
-class raw_ostream;
-
-class DWARFExpressionPrinter {
-public:
-  /// Print a Dwarf expression/
-  /// \param E to be printed
-  /// \param OS to this stream
-  /// \param GetNameForDWARFReg callback to return dwarf register name
-  LLVM_ABI static void print(const DWARFExpression *E, raw_ostream &OS,
-                             DIDumpOptions DumpOpts, DWARFUnit *U,
-                             bool IsEH = false);
-
-  /// Print the expression in a format intended to be compact and useful to a
-  /// user, but not perfectly unambiguous, or capable of representing every
-  /// valid DWARF expression. Returns true if the expression was sucessfully
-  /// printed.
-  ///
-  /// \param E to be printed
-  /// \param OS to this stream
-  /// \param GetNameForDWARFReg callback to return dwarf register name
-  ///
-  /// \returns true if the expression was successfully printed
-  LLVM_ABI static bool printCompact(
-      const DWARFExpression *E, raw_ostream &OS,
-      std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg =
-          nullptr);
-
-  /// Pretty print a register opcode and operands.
-  /// \param U within the context of this Dwarf unit, if any.
-  /// \param OS to this stream
-  /// \param DumpOpts with these options
-  /// \param Opcode to print
-  /// \param Operands to the opcode
-  ///
-  /// returns true if the Op was successfully printed
-  LLVM_ABI static bool prettyPrintRegisterOp(DWARFUnit *U, raw_ostream &OS,
-                                             DIDumpOptions DumpOpts,
-                                             uint8_t Opcode,
-                                             ArrayRef<uint64_t> Operands);
-
-private:
-  static bool printOp(const DWARFExpression::Operation *Op, raw_ostream &OS,
-                      DIDumpOptions DumpOpts, const DWARFExpression *Expr,
-                      DWARFUnit *U);
-
-  static void prettyPrintBaseTypeRef(DWARFUnit *U, raw_ostream &OS,
-                                     DIDumpOptions DumpOpts,
-                                     ArrayRef<uint64_t> Operands,
-                                     unsigned Operand);
-};
-
 } // end namespace llvm
 
 #endif // LLVM_DEBUGINFO_DWARF_DWARFEXPRESSION_H

llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt

@@ -38,6 +38,7 @@ add_llvm_component_library(LLVMAsmPrinter
   Core
   DebugInfoCodeView
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   MC
   MCParser
   Remarks

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -32,7 +32,7 @@
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/Function.h"

llvm/lib/DWARFLinker/Classic/CMakeLists.txt

@@ -19,6 +19,7 @@ add_llvm_component_library(LLVMDWARFLinkerClassic
   CodeGen
   CodeGenTypes
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   DWARFLinker
   MC
   Object

llvm/lib/DWARFLinker/Classic/DWARFLinker.cpp

@@ -23,10 +23,10 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Error.h"

llvm/lib/DWARFLinker/Classic/DWARFLinkerCompileUnit.cpp

@@ -10,7 +10,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/DWARFLinker/Classic/DWARFLinkerDeclContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/FormatVariadic.h"
 
 namespace llvm {

llvm/lib/DWARFLinker/Parallel/CMakeLists.txt

@@ -25,6 +25,7 @@ add_llvm_component_library(LLVMDWARFLinkerParallel
   BinaryFormat
   CodeGen
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   DWARFLinker
   MC
   Object

llvm/lib/DebugInfo/DWARF/CMakeLists.txt

@@ -1,9 +1,10 @@
+add_subdirectory(LowLevel)
+
 add_llvm_component_library(LLVMDebugInfoDWARF
   DWARFAbbreviationDeclaration.cpp
   DWARFAddressRange.cpp
   DWARFAcceleratorTable.cpp
   DWARFCFIPrinter.cpp
-  DWARFCFIProgram.cpp
   DWARFCompileUnit.cpp
   DWARFContext.cpp
   DWARFDebugAbbrev.cpp
@@ -19,7 +20,7 @@ add_llvm_component_library(LLVMDebugInfoDWARF
   DWARFDebugRangeList.cpp
   DWARFDebugRnglists.cpp
   DWARFDie.cpp
-  DWARFExpression.cpp
+  DWARFExpressionPrinter.cpp
   DWARFFormValue.cpp
   DWARFGdbIndex.cpp
   DWARFListTable.cpp
@@ -35,6 +36,7 @@ add_llvm_component_library(LLVMDebugInfoDWARF
 
   LINK_COMPONENTS
   BinaryFormat
+  DebugInfoDWARFLowLevel
   Object
   Support
   TargetParser

llvm/lib/DebugInfo/DWARF/DWARFCFIPrinter.cpp

@@ -8,8 +8,9 @@
 
 #include "llvm/DebugInfo/DWARF/DWARFCFIPrinter.h"
 #include "llvm/DebugInfo/DIContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFCFIProgram.h"
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Errc.h"
@@ -100,8 +101,7 @@ static void printOperand(raw_ostream &OS, const DIDumpOptions &DumpOpts,
   case CFIProgram::OT_Expression:
     assert(Instr.Expression && "missing DWARFExpression object");
     OS << " ";
-    DWARFExpressionPrinter::print(&Instr.Expression.value(), OS, DumpOpts,
+    printDwarfExpression(&Instr.Expression.value(), OS, DumpOpts, nullptr);
-                                  nullptr);
     break;
   }
 }

llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp

@@ -13,9 +13,10 @@
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFCFIPrinter.h"
-#include "llvm/DebugInfo/DWARF/DWARFCFIProgram.h"
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Errc.h"
@@ -114,7 +115,7 @@ void UnwindLocation::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const {
     break;
   case DWARFExpr: {
     if (Expr)
-      DWARFExpressionPrinter::print(&(*Expr), OS, DumpOpts, nullptr);
+      printDwarfExpression(&Expr.value(), OS, DumpOpts, nullptr);
     break;
   }
   case Constant:

llvm/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp

@@ -11,10 +11,11 @@
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
@@ -117,7 +118,7 @@ static void dumpExpression(raw_ostream &OS, DIDumpOptions DumpOpts,
   if (U)
     Format = U->getFormat();
   DWARFExpression E(Extractor, AddressSize, Format);
-  DWARFExpressionPrinter::print(&E, OS, DumpOpts, U);
+  printDwarfExpression(&E, OS, DumpOpts, U);
 }
 
 bool DWARFLocationTable::dumpLocationList(

llvm/lib/DebugInfo/DWARF/DWARFDie.cpp

@@ -15,11 +15,12 @@
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypePrinter.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Format.h"
@@ -99,7 +100,7 @@ static void dumpLocationExpr(raw_ostream &OS, const DWARFFormValue &FormValue,
   DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
                      Ctx.isLittleEndian(), 0);
   DWARFExpression DE(Data, U->getAddressByteSize(), U->getFormParams().Format);
-  DWARFExpressionPrinter::print(&DE, OS, DumpOpts, U);
+  printDwarfExpression(&DE, OS, DumpOpts, U);
 }
 
 static DWARFDie resolveReferencedType(DWARFDie D, DWARFFormValue F) {

llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp

@@ -1,538 +0,0 @@
-//===-- DWARFExpression.cpp -----------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
-#include "llvm/ADT/SmallString.h"
-#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
-#include "llvm/Support/Format.h"
-#include <cassert>
-#include <cstdint>
-#include <vector>
-
-using namespace llvm;
-using namespace dwarf;
-
-namespace llvm {
-
-typedef DWARFExpression::Operation Op;
-typedef Op::Description Desc;
-
-static std::vector<Desc> getOpDescriptions() {
-  std::vector<Desc> Descriptions;
-  Descriptions.resize(0xff);
-  Descriptions[DW_OP_addr] = Desc(Op::Dwarf2, Op::SizeAddr);
-  Descriptions[DW_OP_deref] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_const1u] = Desc(Op::Dwarf2, Op::Size1);
-  Descriptions[DW_OP_const1s] = Desc(Op::Dwarf2, Op::SignedSize1);
-  Descriptions[DW_OP_const2u] = Desc(Op::Dwarf2, Op::Size2);
-  Descriptions[DW_OP_const2s] = Desc(Op::Dwarf2, Op::SignedSize2);
-  Descriptions[DW_OP_const4u] = Desc(Op::Dwarf2, Op::Size4);
-  Descriptions[DW_OP_const4s] = Desc(Op::Dwarf2, Op::SignedSize4);
-  Descriptions[DW_OP_const8u] = Desc(Op::Dwarf2, Op::Size8);
-  Descriptions[DW_OP_const8s] = Desc(Op::Dwarf2, Op::SignedSize8);
-  Descriptions[DW_OP_constu] = Desc(Op::Dwarf2, Op::SizeLEB);
-  Descriptions[DW_OP_consts] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
-  Descriptions[DW_OP_dup] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_drop] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_over] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_pick] = Desc(Op::Dwarf2, Op::Size1);
-  Descriptions[DW_OP_swap] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_rot] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_xderef] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_abs] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_and] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_div] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_minus] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_mod] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_mul] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_neg] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_not] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_or] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_plus] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_plus_uconst] = Desc(Op::Dwarf2, Op::SizeLEB);
-  Descriptions[DW_OP_shl] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_shr] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_shra] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_xor] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_bra] = Desc(Op::Dwarf2, Op::SignedSize2);
-  Descriptions[DW_OP_eq] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_ge] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_gt] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_le] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_lt] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_ne] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_skip] = Desc(Op::Dwarf2, Op::SignedSize2);
-  for (uint16_t LA = DW_OP_lit0; LA <= DW_OP_lit31; ++LA)
-    Descriptions[LA] = Desc(Op::Dwarf2);
-  for (uint16_t LA = DW_OP_reg0; LA <= DW_OP_reg31; ++LA)
-    Descriptions[LA] = Desc(Op::Dwarf2);
-  for (uint16_t LA = DW_OP_breg0; LA <= DW_OP_breg31; ++LA)
-    Descriptions[LA] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
-  Descriptions[DW_OP_regx] = Desc(Op::Dwarf2, Op::SizeLEB);
-  Descriptions[DW_OP_fbreg] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
-  Descriptions[DW_OP_bregx] = Desc(Op::Dwarf2, Op::SizeLEB, Op::SignedSizeLEB);
-  Descriptions[DW_OP_piece] = Desc(Op::Dwarf2, Op::SizeLEB);
-  Descriptions[DW_OP_deref_size] = Desc(Op::Dwarf2, Op::Size1);
-  Descriptions[DW_OP_xderef_size] = Desc(Op::Dwarf2, Op::Size1);
-  Descriptions[DW_OP_nop] = Desc(Op::Dwarf2);
-  Descriptions[DW_OP_push_object_address] = Desc(Op::Dwarf3);
-  Descriptions[DW_OP_call2] = Desc(Op::Dwarf3, Op::Size2);
-  Descriptions[DW_OP_call4] = Desc(Op::Dwarf3, Op::Size4);
-  Descriptions[DW_OP_call_ref] = Desc(Op::Dwarf3, Op::SizeRefAddr);
-  Descriptions[DW_OP_form_tls_address] = Desc(Op::Dwarf3);
-  Descriptions[DW_OP_call_frame_cfa] = Desc(Op::Dwarf3);
-  Descriptions[DW_OP_bit_piece] = Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeLEB);
-  Descriptions[DW_OP_implicit_value] =
-      Desc(Op::Dwarf4, Op::SizeLEB, Op::SizeBlock);
-  Descriptions[DW_OP_stack_value] = Desc(Op::Dwarf4);
-  Descriptions[DW_OP_implicit_pointer] =
-      Desc(Op::Dwarf5, Op::SizeRefAddr, Op::SignedSizeLEB);
-  Descriptions[DW_OP_addrx] = Desc(Op::Dwarf5, Op::SizeLEB);
-  Descriptions[DW_OP_constx] = Desc(Op::Dwarf5, Op::SizeLEB);
-  Descriptions[DW_OP_entry_value] = Desc(Op::Dwarf5, Op::SizeLEB);
-  Descriptions[DW_OP_convert] = Desc(Op::Dwarf5, Op::BaseTypeRef);
-  Descriptions[DW_OP_regval_type] =
-      Desc(Op::Dwarf5, Op::SizeLEB, Op::BaseTypeRef);
-  Descriptions[DW_OP_WASM_location] =
-      Desc(Op::Dwarf4, Op::SizeLEB, Op::WasmLocationArg);
-  Descriptions[DW_OP_GNU_push_tls_address] = Desc(Op::Dwarf3);
-  Descriptions[DW_OP_GNU_addr_index] = Desc(Op::Dwarf4, Op::SizeLEB);
-  Descriptions[DW_OP_GNU_const_index] = Desc(Op::Dwarf4, Op::SizeLEB);
-  Descriptions[DW_OP_GNU_entry_value] = Desc(Op::Dwarf4, Op::SizeLEB);
-  Descriptions[DW_OP_GNU_implicit_pointer] =
-      Desc(Op::Dwarf4, Op::SizeRefAddr, Op::SignedSizeLEB);
-  // This Description acts as a marker that getSubOpDesc must be called
-  // to fetch the final Description for the operation. Each such final
-  // Description must share the same first SizeSubOpLEB operand.
-  Descriptions[DW_OP_LLVM_user] = Desc(Op::Dwarf5, Op::SizeSubOpLEB);
-  return Descriptions;
-}
-
-static Desc getDescImpl(ArrayRef<Desc> Descriptions, unsigned Opcode) {
-  // Handle possible corrupted or unsupported operation.
-  if (Opcode >= Descriptions.size())
-    return {};
-  return Descriptions[Opcode];
-}
-
-static Desc getOpDesc(unsigned Opcode) {
-  static std::vector<Desc> Descriptions = getOpDescriptions();
-  return getDescImpl(Descriptions, Opcode);
-}
-
-static std::vector<Desc> getSubOpDescriptions() {
-  static constexpr unsigned LlvmUserDescriptionsSize = 1
-#define HANDLE_DW_OP_LLVM_USEROP(ID, NAME) +1
-#include "llvm/BinaryFormat/Dwarf.def"
-      ;
-  std::vector<Desc> Descriptions;
-  Descriptions.resize(LlvmUserDescriptionsSize);
-  Descriptions[DW_OP_LLVM_nop] = Desc(Op::Dwarf5, Op::SizeSubOpLEB);
-  return Descriptions;
-}
-
-static Desc getSubOpDesc(unsigned Opcode, unsigned SubOpcode) {
-  assert(Opcode == DW_OP_LLVM_user);
-  static std::vector<Desc> Descriptions = getSubOpDescriptions();
-  return getDescImpl(Descriptions, SubOpcode);
-}
-
-bool DWARFExpression::Operation::extract(DataExtractor Data,
-                                         uint8_t AddressSize, uint64_t Offset,
-                                         std::optional<DwarfFormat> Format) {
-  EndOffset = Offset;
-  Opcode = Data.getU8(&Offset);
-
-  Desc = getOpDesc(Opcode);
-  if (Desc.Version == Operation::DwarfNA)
-    return false;
-
-  Operands.resize(Desc.Op.size());
-  OperandEndOffsets.resize(Desc.Op.size());
-  for (unsigned Operand = 0; Operand < Desc.Op.size(); ++Operand) {
-    unsigned Size = Desc.Op[Operand];
-    unsigned Signed = Size & Operation::SignBit;
-
-    switch (Size & ~Operation::SignBit) {
-    case Operation::SizeSubOpLEB:
-      assert(Operand == 0 && "SubOp operand must be the first operand");
-      Operands[Operand] = Data.getULEB128(&Offset);
-      Desc = getSubOpDesc(Opcode, Operands[Operand]);
-      if (Desc.Version == Operation::DwarfNA)
-        return false;
-      assert(Desc.Op[Operand] == Operation::SizeSubOpLEB &&
-             "SizeSubOpLEB Description must begin with SizeSubOpLEB operand");
-      break;
-    case Operation::Size1:
-      Operands[Operand] = Data.getU8(&Offset);
-      if (Signed)
-        Operands[Operand] = (int8_t)Operands[Operand];
-      break;
-    case Operation::Size2:
-      Operands[Operand] = Data.getU16(&Offset);
-      if (Signed)
-        Operands[Operand] = (int16_t)Operands[Operand];
-      break;
-    case Operation::Size4:
-      Operands[Operand] = Data.getU32(&Offset);
-      if (Signed)
-        Operands[Operand] = (int32_t)Operands[Operand];
-      break;
-    case Operation::Size8:
-      Operands[Operand] = Data.getU64(&Offset);
-      break;
-    case Operation::SizeAddr:
-      Operands[Operand] = Data.getUnsigned(&Offset, AddressSize);
-      break;
-    case Operation::SizeRefAddr:
-      if (!Format)
-        return false;
-      Operands[Operand] =
-          Data.getUnsigned(&Offset, dwarf::getDwarfOffsetByteSize(*Format));
-      break;
-    case Operation::SizeLEB:
-      if (Signed)
-        Operands[Operand] = Data.getSLEB128(&Offset);
-      else
-        Operands[Operand] = Data.getULEB128(&Offset);
-      break;
-    case Operation::BaseTypeRef:
-      Operands[Operand] = Data.getULEB128(&Offset);
-      break;
-    case Operation::WasmLocationArg:
-      assert(Operand == 1);
-      switch (Operands[0]) {
-      case 0:
-      case 1:
-      case 2:
-      case 4:
-        Operands[Operand] = Data.getULEB128(&Offset);
-        break;
-      case 3: // global as uint32
-         Operands[Operand] = Data.getU32(&Offset);
-         break;
-      default:
-        return false; // Unknown Wasm location
-      }
-      break;
-    case Operation::SizeBlock:
-      // We need a size, so this cannot be the first operand
-      if (Operand == 0)
-        return false;
-      // Store the offset of the block as the value.
-      Operands[Operand] = Offset;
-      Offset += Operands[Operand - 1];
-      break;
-    default:
-      llvm_unreachable("Unknown DWARFExpression Op size");
-    }
-
-    OperandEndOffsets[Operand] = Offset;
-  }
-
-  EndOffset = Offset;
-  return true;
-}
-
-std::optional<unsigned> DWARFExpression::Operation::getSubCode() const {
-  if (!Desc.Op.size() || Desc.Op[0] != Operation::SizeSubOpLEB)
-    return std::nullopt;
-  return Operands[0];
-}
-
-bool DWARFExpression::operator==(const DWARFExpression &RHS) const {
-  if (AddressSize != RHS.AddressSize || Format != RHS.Format)
-    return false;
-  return Data.getData() == RHS.Data.getData();
-}
-
-void DWARFExpressionPrinter::prettyPrintBaseTypeRef(DWARFUnit *U,
-                                                    raw_ostream &OS,
-                                                    DIDumpOptions DumpOpts,
-                                                    ArrayRef<uint64_t> Operands,
-                                                    unsigned Operand) {
-  assert(Operand < Operands.size() && "operand out of bounds");
-  if (!U) {
-    OS << format(" <base_type ref: 0x%" PRIx64 ">", Operands[Operand]);
-    return;
-  }
-  auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]);
-  if (Die && Die.getTag() == dwarf::DW_TAG_base_type) {
-    OS << " (";
-    if (DumpOpts.Verbose)
-      OS << format("0x%08" PRIx64 " -> ", Operands[Operand]);
-    OS << format("0x%08" PRIx64 ")", U->getOffset() + Operands[Operand]);
-    if (auto Name = dwarf::toString(Die.find(dwarf::DW_AT_name)))
-      OS << " \"" << *Name << "\"";
-  } else {
-    OS << format(" <invalid base_type ref: 0x%" PRIx64 ">", Operands[Operand]);
-  }
-}
-
-bool DWARFExpressionPrinter::prettyPrintRegisterOp(
-    DWARFUnit *U, raw_ostream &OS, DIDumpOptions DumpOpts, uint8_t Opcode,
-    ArrayRef<uint64_t> Operands) {
-  if (!DumpOpts.GetNameForDWARFReg)
-    return false;
-
-  uint64_t DwarfRegNum;
-  unsigned OpNum = 0;
-
-  if (Opcode == DW_OP_bregx || Opcode == DW_OP_regx ||
-      Opcode == DW_OP_regval_type)
-    DwarfRegNum = Operands[OpNum++];
-  else if (Opcode >= DW_OP_breg0 && Opcode < DW_OP_bregx)
-    DwarfRegNum = Opcode - DW_OP_breg0;
-  else
-    DwarfRegNum = Opcode - DW_OP_reg0;
-
-  auto RegName = DumpOpts.GetNameForDWARFReg(DwarfRegNum, DumpOpts.IsEH);
-  if (!RegName.empty()) {
-    if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) ||
-        Opcode == DW_OP_bregx)
-      OS << ' ' << RegName << format("%+" PRId64, Operands[OpNum]);
-    else
-      OS << ' ' << RegName.data();
-
-    if (Opcode == DW_OP_regval_type)
-      prettyPrintBaseTypeRef(U, OS, DumpOpts, Operands, 1);
-    return true;
-  }
-
-  return false;
-}
-
-bool DWARFExpressionPrinter::printOp(const DWARFExpression::Operation *Op,
-                                     raw_ostream &OS, DIDumpOptions DumpOpts,
-                                     const DWARFExpression *Expr,
-                                     DWARFUnit *U) {
-  if (Op->Error) {
-    OS << "<decoding error>";
-    return false;
-  }
-
-  StringRef Name = OperationEncodingString(Op->Opcode);
-  assert(!Name.empty() && "DW_OP has no name!");
-  OS << Name;
-
-  if ((Op->Opcode >= DW_OP_breg0 && Op->Opcode <= DW_OP_breg31) ||
-      (Op->Opcode >= DW_OP_reg0 && Op->Opcode <= DW_OP_reg31) ||
-      Op->Opcode == DW_OP_bregx || Op->Opcode == DW_OP_regx ||
-      Op->Opcode == DW_OP_regval_type)
-    if (prettyPrintRegisterOp(U, OS, DumpOpts, Op->Opcode, Op->Operands))
-      return true;
-
-  for (unsigned Operand = 0; Operand < Op->Desc.Op.size(); ++Operand) {
-    unsigned Size = Op->Desc.Op[Operand];
-    unsigned Signed = Size & DWARFExpression::Operation::SignBit;
-
-    if (Size == DWARFExpression::Operation::SizeSubOpLEB) {
-      StringRef SubName =
-          SubOperationEncodingString(Op->Opcode, Op->Operands[Operand]);
-      assert(!SubName.empty() && "DW_OP SubOp has no name!");
-      OS << " " << SubName;
-    } else if (Size == DWARFExpression::Operation::BaseTypeRef && U) {
-      // For DW_OP_convert the operand may be 0 to indicate that conversion to
-      // the generic type should be done. The same holds for DW_OP_reinterpret,
-      // which is currently not supported.
-      if (Op->Opcode == DW_OP_convert && Op->Operands[Operand] == 0)
-        OS << " 0x0";
-      else
-        prettyPrintBaseTypeRef(U, OS, DumpOpts, Op->Operands, Operand);
-    } else if (Size == DWARFExpression::Operation::WasmLocationArg) {
-      assert(Operand == 1);
-      switch (Op->Operands[0]) {
-      case 0:
-      case 1:
-      case 2:
-      case 3: // global as uint32
-      case 4:
-        OS << format(" 0x%" PRIx64, Op->Operands[Operand]);
-        break;
-      default: assert(false);
-      }
-    } else if (Size == DWARFExpression::Operation::SizeBlock) {
-      uint64_t Offset = Op->Operands[Operand];
-      for (unsigned i = 0; i < Op->Operands[Operand - 1]; ++i)
-        OS << format(" 0x%02x", Expr->Data.getU8(&Offset));
-    } else {
-      if (Signed)
-        OS << format(" %+" PRId64, (int64_t)Op->Operands[Operand]);
-      else if (Op->Opcode != DW_OP_entry_value &&
-               Op->Opcode != DW_OP_GNU_entry_value)
-        OS << format(" 0x%" PRIx64, Op->Operands[Operand]);
-    }
-  }
-  return true;
-}
-
-void DWARFExpressionPrinter::print(const DWARFExpression *E, raw_ostream &OS,
-                                   DIDumpOptions DumpOpts, DWARFUnit *U,
-                                   bool IsEH) {
-  uint32_t EntryValExprSize = 0;
-  uint64_t EntryValStartOffset = 0;
-  if (E->Data.getData().empty())
-    OS << "<empty>";
-
-  for (auto &Op : *E) {
-    DumpOpts.IsEH = IsEH;
-    if (!printOp(&Op, OS, DumpOpts, E, U)) {
-      uint64_t FailOffset = Op.getEndOffset();
-      while (FailOffset < E->Data.getData().size())
-        OS << format(" %02x", E->Data.getU8(&FailOffset));
-      return;
-    }
-
-    if (Op.getCode() == DW_OP_entry_value ||
-        Op.getCode() == DW_OP_GNU_entry_value) {
-      OS << "(";
-      EntryValExprSize = Op.getRawOperand(0);
-      EntryValStartOffset = Op.getEndOffset();
-      continue;
-    }
-
-    if (EntryValExprSize) {
-      EntryValExprSize -= Op.getEndOffset() - EntryValStartOffset;
-      if (EntryValExprSize == 0)
-        OS << ")";
-    }
-
-    if (Op.getEndOffset() < E->Data.getData().size())
-      OS << ", ";
-  }
-}
-
-/// A user-facing string representation of a DWARF expression. This might be an
-/// Address expression, in which case it will be implicitly dereferenced, or a
-/// Value expression.
-struct PrintedExpr {
-  enum ExprKind {
-    Address,
-    Value,
-  };
-  ExprKind Kind;
-  SmallString<16> String;
-
-  PrintedExpr(ExprKind K = Address) : Kind(K) {}
-};
-
-static bool printCompactDWARFExpr(
-    raw_ostream &OS, DWARFExpression::iterator I,
-    const DWARFExpression::iterator E,
-    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg =
-        nullptr) {
-  SmallVector<PrintedExpr, 4> Stack;
-
-  while (I != E) {
-    const DWARFExpression::Operation &Op = *I;
-    uint8_t Opcode = Op.getCode();
-    switch (Opcode) {
-    case dwarf::DW_OP_regx: {
-      // DW_OP_regx: A register, with the register num given as an operand.
-      // Printed as the plain register name.
-      uint64_t DwarfRegNum = Op.getRawOperand(0);
-      auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
-      if (RegName.empty())
-        return false;
-      raw_svector_ostream S(Stack.emplace_back(PrintedExpr::Value).String);
-      S << RegName;
-      break;
-    }
-    case dwarf::DW_OP_bregx: {
-      int DwarfRegNum = Op.getRawOperand(0);
-      int64_t Offset = Op.getRawOperand(1);
-      auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
-      if (RegName.empty())
-        return false;
-      raw_svector_ostream S(Stack.emplace_back().String);
-      S << RegName;
-      if (Offset)
-        S << format("%+" PRId64, Offset);
-      break;
-    }
-    case dwarf::DW_OP_entry_value:
-    case dwarf::DW_OP_GNU_entry_value: {
-      // DW_OP_entry_value contains a sub-expression which must be rendered
-      // separately.
-      uint64_t SubExprLength = Op.getRawOperand(0);
-      DWARFExpression::iterator SubExprEnd = I.skipBytes(SubExprLength);
-      ++I;
-      raw_svector_ostream S(Stack.emplace_back().String);
-      S << "entry(";
-      printCompactDWARFExpr(S, I, SubExprEnd, GetNameForDWARFReg);
-      S << ")";
-      I = SubExprEnd;
-      continue;
-    }
-    case dwarf::DW_OP_stack_value: {
-      // The top stack entry should be treated as the actual value of tne
-      // variable, rather than the address of the variable in memory.
-      assert(!Stack.empty());
-      Stack.back().Kind = PrintedExpr::Value;
-      break;
-    }
-    case dwarf::DW_OP_nop: {
-      break;
-    }
-    case dwarf::DW_OP_LLVM_user: {
-      assert(Op.getSubCode() == dwarf::DW_OP_LLVM_nop);
-      break;
-    }
-    default:
-      if (Opcode >= dwarf::DW_OP_reg0 && Opcode <= dwarf::DW_OP_reg31) {
-        // DW_OP_reg<N>: A register, with the register num implied by the
-        // opcode. Printed as the plain register name.
-        uint64_t DwarfRegNum = Opcode - dwarf::DW_OP_reg0;
-        auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
-        if (RegName.empty())
-          return false;
-        raw_svector_ostream S(Stack.emplace_back(PrintedExpr::Value).String);
-        S << RegName;
-      } else if (Opcode >= dwarf::DW_OP_breg0 &&
-                 Opcode <= dwarf::DW_OP_breg31) {
-        int DwarfRegNum = Opcode - dwarf::DW_OP_breg0;
-        int64_t Offset = Op.getRawOperand(0);
-        auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
-        if (RegName.empty())
-          return false;
-        raw_svector_ostream S(Stack.emplace_back().String);
-        S << RegName;
-        if (Offset)
-          S << format("%+" PRId64, Offset);
-      } else {
-        // If we hit an unknown operand, we don't know its effect on the stack,
-        // so bail out on the whole expression.
-        OS << "<unknown op " << dwarf::OperationEncodingString(Opcode) << " ("
-           << (int)Opcode << ")>";
-        return false;
-      }
-      break;
-    }
-    ++I;
-  }
-
-  if (Stack.size() != 1) {
-    OS << "<stack of size " << Stack.size() << ", expected 1>";
-    return false;
-  }
-
-  if (Stack.front().Kind == PrintedExpr::Address)
-    OS << "[" << Stack.front().String << "]";
-  else
-    OS << Stack.front().String;
-
-  return true;
-}
-
-bool DWARFExpressionPrinter::printCompact(
-    const DWARFExpression *E, raw_ostream &OS,
-    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg) {
-  return printCompactDWARFExpr(OS, E->begin(), E->end(), GetNameForDWARFReg);
-}
-
-} // namespace llvm

llvm/lib/DebugInfo/DWARF/DWARFExpressionPrinter.cpp

@@ -0,0 +1,311 @@
+//===-- DWARFExpression.cpp -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
+#include "llvm/Support/Format.h"
+#include <cassert>
+#include <cstdint>
+#include <vector>
+
+using namespace llvm;
+using namespace dwarf;
+
+namespace llvm {
+
+typedef DWARFExpression::Operation Op;
+typedef Op::Description Desc;
+
+static void prettyPrintBaseTypeRef(DWARFUnit *U, raw_ostream &OS,
+                                   DIDumpOptions DumpOpts,
+                                   ArrayRef<uint64_t> Operands,
+                                   unsigned Operand) {
+  assert(Operand < Operands.size() && "operand out of bounds");
+  if (!U) {
+    OS << format(" <base_type ref: 0x%" PRIx64 ">", Operands[Operand]);
+    return;
+  }
+  auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]);
+  if (Die && Die.getTag() == dwarf::DW_TAG_base_type) {
+    OS << " (";
+    if (DumpOpts.Verbose)
+      OS << format("0x%08" PRIx64 " -> ", Operands[Operand]);
+    OS << format("0x%08" PRIx64 ")", U->getOffset() + Operands[Operand]);
+    if (auto Name = dwarf::toString(Die.find(dwarf::DW_AT_name)))
+      OS << " \"" << *Name << "\"";
+  } else {
+    OS << format(" <invalid base_type ref: 0x%" PRIx64 ">", Operands[Operand]);
+  }
+}
+
+static bool printOp(const DWARFExpression::Operation *Op, raw_ostream &OS,
+                    DIDumpOptions DumpOpts, const DWARFExpression *Expr,
+                    DWARFUnit *U) {
+  if (Op->isError()) {
+    OS << "<decoding error>";
+    return false;
+  }
+
+  StringRef Name = OperationEncodingString(Op->getCode());
+  assert(!Name.empty() && "DW_OP has no name!");
+  OS << Name;
+
+  if ((Op->getCode() >= DW_OP_breg0 && Op->getCode() <= DW_OP_breg31) ||
+      (Op->getCode() >= DW_OP_reg0 && Op->getCode() <= DW_OP_reg31) ||
+      Op->getCode() == DW_OP_bregx || Op->getCode() == DW_OP_regx ||
+      Op->getCode() == DW_OP_regval_type)
+    if (prettyPrintRegisterOp(U, OS, DumpOpts, Op->getCode(),
+                              Op->getRawOperands()))
+      return true;
+
+  for (unsigned Operand = 0; Operand < Op->getDescription().Op.size();
+       ++Operand) {
+    unsigned Size = Op->getDescription().Op[Operand];
+    unsigned Signed = Size & DWARFExpression::Operation::SignBit;
+
+    if (Size == DWARFExpression::Operation::SizeSubOpLEB) {
+      StringRef SubName =
+          SubOperationEncodingString(Op->getCode(), Op->getRawOperand(Operand));
+      assert(!SubName.empty() && "DW_OP SubOp has no name!");
+      OS << " " << SubName;
+    } else if (Size == DWARFExpression::Operation::BaseTypeRef && U) {
+      // For DW_OP_convert the operand may be 0 to indicate that conversion to
+      // the generic type should be done. The same holds for DW_OP_reinterpret,
+      // which is currently not supported.
+      if (Op->getCode() == DW_OP_convert && Op->getRawOperand(Operand) == 0)
+        OS << " 0x0";
+      else
+        prettyPrintBaseTypeRef(U, OS, DumpOpts, Op->getRawOperands(), Operand);
+    } else if (Size == DWARFExpression::Operation::WasmLocationArg) {
+      assert(Operand == 1);
+      switch (Op->getRawOperand(0)) {
+      case 0:
+      case 1:
+      case 2:
+      case 3: // global as uint32
+      case 4:
+        OS << format(" 0x%" PRIx64, Op->getRawOperand(Operand));
+        break;
+      default:
+        assert(false);
+      }
+    } else if (Size == DWARFExpression::Operation::SizeBlock) {
+      uint64_t Offset = Op->getRawOperand(Operand);
+      for (unsigned i = 0; i < Op->getRawOperand(Operand - 1); ++i)
+        OS << format(" 0x%02x",
+                     static_cast<uint8_t>(Expr->getData()[Offset++]));
+    } else {
+      if (Signed)
+        OS << format(" %+" PRId64, (int64_t)Op->getRawOperand(Operand));
+      else if (Op->getCode() != DW_OP_entry_value &&
+               Op->getCode() != DW_OP_GNU_entry_value)
+        OS << format(" 0x%" PRIx64, Op->getRawOperand(Operand));
+    }
+  }
+  return true;
+}
+
+void printDwarfExpression(const DWARFExpression *E, raw_ostream &OS,
+                          DIDumpOptions DumpOpts, DWARFUnit *U, bool IsEH) {
+  uint32_t EntryValExprSize = 0;
+  uint64_t EntryValStartOffset = 0;
+  if (E->getData().empty())
+    OS << "<empty>";
+
+  for (auto &Op : *E) {
+    DumpOpts.IsEH = IsEH;
+    if (!printOp(&Op, OS, DumpOpts, E, U)) {
+      uint64_t FailOffset = Op.getEndOffset();
+      while (FailOffset < E->getData().size())
+        OS << format(" %02x", static_cast<uint8_t>(E->getData()[FailOffset++]));
+      return;
+    }
+
+    if (Op.getCode() == DW_OP_entry_value ||
+        Op.getCode() == DW_OP_GNU_entry_value) {
+      OS << "(";
+      EntryValExprSize = Op.getRawOperand(0);
+      EntryValStartOffset = Op.getEndOffset();
+      continue;
+    }
+
+    if (EntryValExprSize) {
+      EntryValExprSize -= Op.getEndOffset() - EntryValStartOffset;
+      if (EntryValExprSize == 0)
+        OS << ")";
+    }
+
+    if (Op.getEndOffset() < E->getData().size())
+      OS << ", ";
+  }
+}
+
+/// A user-facing string representation of a DWARF expression. This might be an
+/// Address expression, in which case it will be implicitly dereferenced, or a
+/// Value expression.
+struct PrintedExpr {
+  enum ExprKind {
+    Address,
+    Value,
+  };
+  ExprKind Kind;
+  SmallString<16> String;
+
+  PrintedExpr(ExprKind K = Address) : Kind(K) {}
+};
+
+static bool printCompactDWARFExpr(
+    raw_ostream &OS, DWARFExpression::iterator I,
+    const DWARFExpression::iterator E,
+    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg =
+        nullptr) {
+  SmallVector<PrintedExpr, 4> Stack;
+
+  while (I != E) {
+    const DWARFExpression::Operation &Op = *I;
+    uint8_t Opcode = Op.getCode();
+    switch (Opcode) {
+    case dwarf::DW_OP_regx: {
+      // DW_OP_regx: A register, with the register num given as an operand.
+      // Printed as the plain register name.
+      uint64_t DwarfRegNum = Op.getRawOperand(0);
+      auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
+      if (RegName.empty())
+        return false;
+      raw_svector_ostream S(Stack.emplace_back(PrintedExpr::Value).String);
+      S << RegName;
+      break;
+    }
+    case dwarf::DW_OP_bregx: {
+      int DwarfRegNum = Op.getRawOperand(0);
+      int64_t Offset = Op.getRawOperand(1);
+      auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
+      if (RegName.empty())
+        return false;
+      raw_svector_ostream S(Stack.emplace_back().String);
+      S << RegName;
+      if (Offset)
+        S << format("%+" PRId64, Offset);
+      break;
+    }
+    case dwarf::DW_OP_entry_value:
+    case dwarf::DW_OP_GNU_entry_value: {
+      // DW_OP_entry_value contains a sub-expression which must be rendered
+      // separately.
+      uint64_t SubExprLength = Op.getRawOperand(0);
+      DWARFExpression::iterator SubExprEnd = I.skipBytes(SubExprLength);
+      ++I;
+      raw_svector_ostream S(Stack.emplace_back().String);
+      S << "entry(";
+      printCompactDWARFExpr(S, I, SubExprEnd, GetNameForDWARFReg);
+      S << ")";
+      I = SubExprEnd;
+      continue;
+    }
+    case dwarf::DW_OP_stack_value: {
+      // The top stack entry should be treated as the actual value of tne
+      // variable, rather than the address of the variable in memory.
+      assert(!Stack.empty());
+      Stack.back().Kind = PrintedExpr::Value;
+      break;
+    }
+    case dwarf::DW_OP_nop: {
+      break;
+    }
+    case dwarf::DW_OP_LLVM_user: {
+      assert(Op.getSubCode() == dwarf::DW_OP_LLVM_nop);
+      break;
+    }
+    default:
+      if (Opcode >= dwarf::DW_OP_reg0 && Opcode <= dwarf::DW_OP_reg31) {
+        // DW_OP_reg<N>: A register, with the register num implied by the
+        // opcode. Printed as the plain register name.
+        uint64_t DwarfRegNum = Opcode - dwarf::DW_OP_reg0;
+        auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
+        if (RegName.empty())
+          return false;
+        raw_svector_ostream S(Stack.emplace_back(PrintedExpr::Value).String);
+        S << RegName;
+      } else if (Opcode >= dwarf::DW_OP_breg0 &&
+                 Opcode <= dwarf::DW_OP_breg31) {
+        int DwarfRegNum = Opcode - dwarf::DW_OP_breg0;
+        int64_t Offset = Op.getRawOperand(0);
+        auto RegName = GetNameForDWARFReg(DwarfRegNum, false);
+        if (RegName.empty())
+          return false;
+        raw_svector_ostream S(Stack.emplace_back().String);
+        S << RegName;
+        if (Offset)
+          S << format("%+" PRId64, Offset);
+      } else {
+        // If we hit an unknown operand, we don't know its effect on the stack,
+        // so bail out on the whole expression.
+        OS << "<unknown op " << dwarf::OperationEncodingString(Opcode) << " ("
+           << (int)Opcode << ")>";
+        return false;
+      }
+      break;
+    }
+    ++I;
+  }
+
+  if (Stack.size() != 1) {
+    OS << "<stack of size " << Stack.size() << ", expected 1>";
+    return false;
+  }
+
+  if (Stack.front().Kind == PrintedExpr::Address)
+    OS << "[" << Stack.front().String << "]";
+  else
+    OS << Stack.front().String;
+
+  return true;
+}
+
+bool printDwarfExpressionCompact(
+    const DWARFExpression *E, raw_ostream &OS,
+    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg) {
+  return printCompactDWARFExpr(OS, E->begin(), E->end(), GetNameForDWARFReg);
+}
+
+bool prettyPrintRegisterOp(DWARFUnit *U, raw_ostream &OS,
+                           DIDumpOptions DumpOpts, uint8_t Opcode,
+                           ArrayRef<uint64_t> Operands) {
+  if (!DumpOpts.GetNameForDWARFReg)
+    return false;
+
+  uint64_t DwarfRegNum;
+  unsigned OpNum = 0;
+
+  if (Opcode == DW_OP_bregx || Opcode == DW_OP_regx ||
+      Opcode == DW_OP_regval_type)
+    DwarfRegNum = Operands[OpNum++];
+  else if (Opcode >= DW_OP_breg0 && Opcode < DW_OP_bregx)
+    DwarfRegNum = Opcode - DW_OP_breg0;
+  else
+    DwarfRegNum = Opcode - DW_OP_reg0;
+
+  auto RegName = DumpOpts.GetNameForDWARFReg(DwarfRegNum, DumpOpts.IsEH);
+  if (!RegName.empty()) {
+    if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) ||
+        Opcode == DW_OP_bregx)
+      OS << ' ' << RegName << format("%+" PRId64, Operands[OpNum]);
+    else
+      OS << ' ' << RegName.data();
+
+    if (Opcode == DW_OP_regval_type)
+      prettyPrintBaseTypeRef(U, OS, DumpOpts, Operands, 1);
+    return true;
+  }
+
+  return false;
+}
+
+} // namespace llvm

llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

@@ -19,12 +19,12 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFListTable.h"
 #include "llvm/DebugInfo/DWARF/DWARFObject.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Errc.h"

llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp

@@ -19,13 +19,13 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFObject.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Object/Error.h"
 #include "llvm/Support/DJB.h"
 #include "llvm/Support/Error.h"

llvm/lib/DebugInfo/DWARF/LowLevel/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_llvm_component_library(LLVMDebugInfoDWARFLowLevel
+  DWARFCFIProgram.cpp
+  DWARFExpression.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/DebugInfo/DWARF/LowLevel
+
+  // This code should have almost no dependencies. Anything that needs
+  // more should use the higher-level DebugInfo/DWARF/ library.
+  LINK_COMPONENTS
+  BinaryFormat
+  Support
+  TargetParser
+  )

llvm/lib/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.cpp

@@ -6,9 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/DebugInfo/DWARF/DWARFCFIProgram.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFCFIProgram.h"
-#include "llvm/DebugInfo/DIContext.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFDataExtractorSimple.h"
-#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Errc.h"
@@ -23,149 +22,6 @@
 using namespace llvm;
 using namespace dwarf;
 
-// See DWARF standard v3, section 7.23
-const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0;
-const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f;
-
-Error CFIProgram::parse(DWARFDataExtractor Data, uint64_t *Offset,
-                        uint64_t EndOffset) {
-  DataExtractor::Cursor C(*Offset);
-  while (C && C.tell() < EndOffset) {
-    uint8_t Opcode = Data.getRelocatedValue(C, 1);
-    if (!C)
-      break;
-
-    // Some instructions have a primary opcode encoded in the top bits.
-    if (uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK) {
-      // If it's a primary opcode, the first operand is encoded in the bottom
-      // bits of the opcode itself.
-      uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK;
-      switch (Primary) {
-      case DW_CFA_advance_loc:
-      case DW_CFA_restore:
-        addInstruction(Primary, Op1);
-        break;
-      case DW_CFA_offset:
-        addInstruction(Primary, Op1, Data.getULEB128(C));
-        break;
-      default:
-        llvm_unreachable("invalid primary CFI opcode");
-      }
-      continue;
-    }
-
-    // Extended opcode - its value is Opcode itself.
-    switch (Opcode) {
-    default:
-      return createStringError(errc::illegal_byte_sequence,
-                               "invalid extended CFI opcode 0x%" PRIx8, Opcode);
-    case DW_CFA_nop:
-    case DW_CFA_remember_state:
-    case DW_CFA_restore_state:
-    case DW_CFA_GNU_window_save:
-    case DW_CFA_AARCH64_negate_ra_state_with_pc:
-      // No operands
-      addInstruction(Opcode);
-      break;
-    case DW_CFA_set_loc:
-      // Operands: Address
-      addInstruction(Opcode, Data.getRelocatedAddress(C));
-      break;
-    case DW_CFA_advance_loc1:
-      // Operands: 1-byte delta
-      addInstruction(Opcode, Data.getRelocatedValue(C, 1));
-      break;
-    case DW_CFA_advance_loc2:
-      // Operands: 2-byte delta
-      addInstruction(Opcode, Data.getRelocatedValue(C, 2));
-      break;
-    case DW_CFA_advance_loc4:
-      // Operands: 4-byte delta
-      addInstruction(Opcode, Data.getRelocatedValue(C, 4));
-      break;
-    case DW_CFA_restore_extended:
-    case DW_CFA_undefined:
-    case DW_CFA_same_value:
-    case DW_CFA_def_cfa_register:
-    case DW_CFA_def_cfa_offset:
-    case DW_CFA_GNU_args_size:
-      // Operands: ULEB128
-      addInstruction(Opcode, Data.getULEB128(C));
-      break;
-    case DW_CFA_def_cfa_offset_sf:
-      // Operands: SLEB128
-      addInstruction(Opcode, Data.getSLEB128(C));
-      break;
-    case DW_CFA_LLVM_def_aspace_cfa:
-    case DW_CFA_LLVM_def_aspace_cfa_sf: {
-      auto RegNum = Data.getULEB128(C);
-      auto CfaOffset = Opcode == DW_CFA_LLVM_def_aspace_cfa
-                           ? Data.getULEB128(C)
-                           : Data.getSLEB128(C);
-      auto AddressSpace = Data.getULEB128(C);
-      addInstruction(Opcode, RegNum, CfaOffset, AddressSpace);
-      break;
-    }
-    case DW_CFA_offset_extended:
-    case DW_CFA_register:
-    case DW_CFA_def_cfa:
-    case DW_CFA_val_offset: {
-      // Operands: ULEB128, ULEB128
-      // Note: We can not embed getULEB128 directly into function
-      // argument list. getULEB128 changes Offset and order of evaluation
-      // for arguments is unspecified.
-      uint64_t op1 = Data.getULEB128(C);
-      uint64_t op2 = Data.getULEB128(C);
-      addInstruction(Opcode, op1, op2);
-      break;
-    }
-    case DW_CFA_offset_extended_sf:
-    case DW_CFA_def_cfa_sf:
-    case DW_CFA_val_offset_sf: {
-      // Operands: ULEB128, SLEB128
-      // Note: see comment for the previous case
-      uint64_t op1 = Data.getULEB128(C);
-      uint64_t op2 = (uint64_t)Data.getSLEB128(C);
-      addInstruction(Opcode, op1, op2);
-      break;
-    }
-    case DW_CFA_def_cfa_expression: {
-      uint64_t ExprLength = Data.getULEB128(C);
-      addInstruction(Opcode, 0);
-      StringRef Expression = Data.getBytes(C, ExprLength);
-
-      DataExtractor Extractor(Expression, Data.isLittleEndian(),
-                              Data.getAddressSize());
-      // Note. We do not pass the DWARF format to DWARFExpression, because
-      // DW_OP_call_ref, the only operation which depends on the format, is
-      // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5.
-      Instructions.back().Expression =
-          DWARFExpression(Extractor, Data.getAddressSize());
-      break;
-    }
-    case DW_CFA_expression:
-    case DW_CFA_val_expression: {
-      uint64_t RegNum = Data.getULEB128(C);
-      addInstruction(Opcode, RegNum, 0);
-
-      uint64_t BlockLength = Data.getULEB128(C);
-      StringRef Expression = Data.getBytes(C, BlockLength);
-      DataExtractor Extractor(Expression, Data.isLittleEndian(),
-                              Data.getAddressSize());
-      // Note. We do not pass the DWARF format to DWARFExpression, because
-      // DW_OP_call_ref, the only operation which depends on the format, is
-      // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5.
-      Instructions.back().Expression =
-          DWARFExpression(Extractor, Data.getAddressSize());
-      break;
-    }
-    }
-  }
-
-  *Offset = C.tell();
-  return C.takeError();
-}
-
 StringRef CFIProgram::callFrameString(unsigned Opcode) const {
   return dwarf::CallFrameString(Opcode, Arch);
 }

llvm/lib/DebugInfo/DWARF/LowLevel/DWARFExpression.cpp

@@ -0,0 +1,253 @@
+//===-- DWARFExpression.cpp -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Format.h"
+#include <cassert>
+#include <cstdint>
+#include <vector>
+
+using namespace llvm;
+using namespace dwarf;
+
+namespace llvm {
+
+typedef DWARFExpression::Operation Op;
+typedef Op::Description Desc;
+
+static std::vector<Desc> getOpDescriptions() {
+  std::vector<Desc> Descriptions;
+  Descriptions.resize(0xff);
+  Descriptions[DW_OP_addr] = Desc(Op::Dwarf2, Op::SizeAddr);
+  Descriptions[DW_OP_deref] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_const1u] = Desc(Op::Dwarf2, Op::Size1);
+  Descriptions[DW_OP_const1s] = Desc(Op::Dwarf2, Op::SignedSize1);
+  Descriptions[DW_OP_const2u] = Desc(Op::Dwarf2, Op::Size2);
+  Descriptions[DW_OP_const2s] = Desc(Op::Dwarf2, Op::SignedSize2);
+  Descriptions[DW_OP_const4u] = Desc(Op::Dwarf2, Op::Size4);
+  Descriptions[DW_OP_const4s] = Desc(Op::Dwarf2, Op::SignedSize4);
+  Descriptions[DW_OP_const8u] = Desc(Op::Dwarf2, Op::Size8);
+  Descriptions[DW_OP_const8s] = Desc(Op::Dwarf2, Op::SignedSize8);
+  Descriptions[DW_OP_constu] = Desc(Op::Dwarf2, Op::SizeLEB);
+  Descriptions[DW_OP_consts] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
+  Descriptions[DW_OP_dup] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_drop] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_over] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_pick] = Desc(Op::Dwarf2, Op::Size1);
+  Descriptions[DW_OP_swap] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_rot] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_xderef] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_abs] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_and] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_div] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_minus] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_mod] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_mul] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_neg] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_not] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_or] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_plus] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_plus_uconst] = Desc(Op::Dwarf2, Op::SizeLEB);
+  Descriptions[DW_OP_shl] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_shr] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_shra] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_xor] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_bra] = Desc(Op::Dwarf2, Op::SignedSize2);
+  Descriptions[DW_OP_eq] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_ge] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_gt] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_le] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_lt] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_ne] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_skip] = Desc(Op::Dwarf2, Op::SignedSize2);
+  for (uint16_t LA = DW_OP_lit0; LA <= DW_OP_lit31; ++LA)
+    Descriptions[LA] = Desc(Op::Dwarf2);
+  for (uint16_t LA = DW_OP_reg0; LA <= DW_OP_reg31; ++LA)
+    Descriptions[LA] = Desc(Op::Dwarf2);
+  for (uint16_t LA = DW_OP_breg0; LA <= DW_OP_breg31; ++LA)
+    Descriptions[LA] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
+  Descriptions[DW_OP_regx] = Desc(Op::Dwarf2, Op::SizeLEB);
+  Descriptions[DW_OP_fbreg] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
+  Descriptions[DW_OP_bregx] = Desc(Op::Dwarf2, Op::SizeLEB, Op::SignedSizeLEB);
+  Descriptions[DW_OP_piece] = Desc(Op::Dwarf2, Op::SizeLEB);
+  Descriptions[DW_OP_deref_size] = Desc(Op::Dwarf2, Op::Size1);
+  Descriptions[DW_OP_xderef_size] = Desc(Op::Dwarf2, Op::Size1);
+  Descriptions[DW_OP_nop] = Desc(Op::Dwarf2);
+  Descriptions[DW_OP_push_object_address] = Desc(Op::Dwarf3);
+  Descriptions[DW_OP_call2] = Desc(Op::Dwarf3, Op::Size2);
+  Descriptions[DW_OP_call4] = Desc(Op::Dwarf3, Op::Size4);
+  Descriptions[DW_OP_call_ref] = Desc(Op::Dwarf3, Op::SizeRefAddr);
+  Descriptions[DW_OP_form_tls_address] = Desc(Op::Dwarf3);
+  Descriptions[DW_OP_call_frame_cfa] = Desc(Op::Dwarf3);
+  Descriptions[DW_OP_bit_piece] = Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeLEB);
+  Descriptions[DW_OP_implicit_value] =
+      Desc(Op::Dwarf4, Op::SizeLEB, Op::SizeBlock);
+  Descriptions[DW_OP_stack_value] = Desc(Op::Dwarf4);
+  Descriptions[DW_OP_implicit_pointer] =
+      Desc(Op::Dwarf5, Op::SizeRefAddr, Op::SignedSizeLEB);
+  Descriptions[DW_OP_addrx] = Desc(Op::Dwarf5, Op::SizeLEB);
+  Descriptions[DW_OP_constx] = Desc(Op::Dwarf5, Op::SizeLEB);
+  Descriptions[DW_OP_entry_value] = Desc(Op::Dwarf5, Op::SizeLEB);
+  Descriptions[DW_OP_convert] = Desc(Op::Dwarf5, Op::BaseTypeRef);
+  Descriptions[DW_OP_regval_type] =
+      Desc(Op::Dwarf5, Op::SizeLEB, Op::BaseTypeRef);
+  Descriptions[DW_OP_WASM_location] =
+      Desc(Op::Dwarf4, Op::SizeLEB, Op::WasmLocationArg);
+  Descriptions[DW_OP_GNU_push_tls_address] = Desc(Op::Dwarf3);
+  Descriptions[DW_OP_GNU_addr_index] = Desc(Op::Dwarf4, Op::SizeLEB);
+  Descriptions[DW_OP_GNU_const_index] = Desc(Op::Dwarf4, Op::SizeLEB);
+  Descriptions[DW_OP_GNU_entry_value] = Desc(Op::Dwarf4, Op::SizeLEB);
+  Descriptions[DW_OP_GNU_implicit_pointer] =
+      Desc(Op::Dwarf4, Op::SizeRefAddr, Op::SignedSizeLEB);
+  // This Description acts as a marker that getSubOpDesc must be called
+  // to fetch the final Description for the operation. Each such final
+  // Description must share the same first SizeSubOpLEB operand.
+  Descriptions[DW_OP_LLVM_user] = Desc(Op::Dwarf5, Op::SizeSubOpLEB);
+  return Descriptions;
+}
+
+static Desc getDescImpl(ArrayRef<Desc> Descriptions, unsigned Opcode) {
+  // Handle possible corrupted or unsupported operation.
+  if (Opcode >= Descriptions.size())
+    return {};
+  return Descriptions[Opcode];
+}
+
+static Desc getOpDesc(unsigned Opcode) {
+  static std::vector<Desc> Descriptions = getOpDescriptions();
+  return getDescImpl(Descriptions, Opcode);
+}
+
+static std::vector<Desc> getSubOpDescriptions() {
+  static constexpr unsigned LlvmUserDescriptionsSize = 1
+#define HANDLE_DW_OP_LLVM_USEROP(ID, NAME) +1
+#include "llvm/BinaryFormat/Dwarf.def"
+      ;
+  std::vector<Desc> Descriptions;
+  Descriptions.resize(LlvmUserDescriptionsSize);
+  Descriptions[DW_OP_LLVM_nop] = Desc(Op::Dwarf5, Op::SizeSubOpLEB);
+  return Descriptions;
+}
+
+static Desc getSubOpDesc(unsigned Opcode, unsigned SubOpcode) {
+  assert(Opcode == DW_OP_LLVM_user);
+  static std::vector<Desc> Descriptions = getSubOpDescriptions();
+  return getDescImpl(Descriptions, SubOpcode);
+}
+
+bool DWARFExpression::Operation::extract(DataExtractor Data,
+                                         uint8_t AddressSize, uint64_t Offset,
+                                         std::optional<DwarfFormat> Format) {
+  EndOffset = Offset;
+  Opcode = Data.getU8(&Offset);
+
+  Desc = getOpDesc(Opcode);
+  if (Desc.Version == Operation::DwarfNA)
+    return false;
+
+  Operands.resize(Desc.Op.size());
+  OperandEndOffsets.resize(Desc.Op.size());
+  for (unsigned Operand = 0; Operand < Desc.Op.size(); ++Operand) {
+    unsigned Size = Desc.Op[Operand];
+    unsigned Signed = Size & Operation::SignBit;
+
+    switch (Size & ~Operation::SignBit) {
+    case Operation::SizeSubOpLEB:
+      assert(Operand == 0 && "SubOp operand must be the first operand");
+      Operands[Operand] = Data.getULEB128(&Offset);
+      Desc = getSubOpDesc(Opcode, Operands[Operand]);
+      if (Desc.Version == Operation::DwarfNA)
+        return false;
+      assert(Desc.Op[Operand] == Operation::SizeSubOpLEB &&
+             "SizeSubOpLEB Description must begin with SizeSubOpLEB operand");
+      break;
+    case Operation::Size1:
+      Operands[Operand] = Data.getU8(&Offset);
+      if (Signed)
+        Operands[Operand] = (int8_t)Operands[Operand];
+      break;
+    case Operation::Size2:
+      Operands[Operand] = Data.getU16(&Offset);
+      if (Signed)
+        Operands[Operand] = (int16_t)Operands[Operand];
+      break;
+    case Operation::Size4:
+      Operands[Operand] = Data.getU32(&Offset);
+      if (Signed)
+        Operands[Operand] = (int32_t)Operands[Operand];
+      break;
+    case Operation::Size8:
+      Operands[Operand] = Data.getU64(&Offset);
+      break;
+    case Operation::SizeAddr:
+      Operands[Operand] = Data.getUnsigned(&Offset, AddressSize);
+      break;
+    case Operation::SizeRefAddr:
+      if (!Format)
+        return false;
+      Operands[Operand] =
+          Data.getUnsigned(&Offset, dwarf::getDwarfOffsetByteSize(*Format));
+      break;
+    case Operation::SizeLEB:
+      if (Signed)
+        Operands[Operand] = Data.getSLEB128(&Offset);
+      else
+        Operands[Operand] = Data.getULEB128(&Offset);
+      break;
+    case Operation::BaseTypeRef:
+      Operands[Operand] = Data.getULEB128(&Offset);
+      break;
+    case Operation::WasmLocationArg:
+      assert(Operand == 1);
+      switch (Operands[0]) {
+      case 0:
+      case 1:
+      case 2:
+      case 4:
+        Operands[Operand] = Data.getULEB128(&Offset);
+        break;
+      case 3: // global as uint32
+        Operands[Operand] = Data.getU32(&Offset);
+        break;
+      default:
+        return false; // Unknown Wasm location
+      }
+      break;
+    case Operation::SizeBlock:
+      // We need a size, so this cannot be the first operand
+      if (Operand == 0)
+        return false;
+      // Store the offset of the block as the value.
+      Operands[Operand] = Offset;
+      Offset += Operands[Operand - 1];
+      break;
+    default:
+      llvm_unreachable("Unknown DWARFExpression Op size");
+    }
+
+    OperandEndOffsets[Operand] = Offset;
+  }
+
+  EndOffset = Offset;
+  return true;
+}
+
+std::optional<unsigned> DWARFExpression::Operation::getSubCode() const {
+  if (!Desc.Op.size() || Desc.Op[0] != Operation::SizeSubOpLEB)
+    return std::nullopt;
+  return Operands[0];
+}
+
+bool DWARFExpression::operator==(const DWARFExpression &RHS) const {
+  if (AddressSize != RHS.AddressSize || Format != RHS.Format)
+    return false;
+  return Data.getData() == RHS.Data.getData();
+}
+
+} // namespace llvm

llvm/lib/DebugInfo/LogicalView/CMakeLists.txt

@@ -47,7 +47,8 @@ add_llvm_component_library(LLVMDebugInfoLogicalView
   MC
   Support
   TargetParser
-  DebugInfoDWARF
   DebugInfoCodeView
+  DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   DebugInfoPDB
   )

llvm/lib/DebugInfo/LogicalView/Readers/LVDWARFReader.cpp

@@ -14,7 +14,8 @@
 #include "llvm/DebugInfo/LogicalView/Readers/LVDWARFReader.h"
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/DebugInfo/LogicalView/Core/LVLine.h"
 #include "llvm/DebugInfo/LogicalView/Core/LVScope.h"
 #include "llvm/DebugInfo/LogicalView/Core/LVSymbol.h"
@@ -594,8 +595,7 @@ std::string LVDWARFReader::getRegisterName(LVSmall Opcode,
     return {};
   };
   DumpOpts.GetNameForDWARFReg = GetRegName;
-  DWARFExpressionPrinter::prettyPrintRegisterOp(/*U=*/nullptr, Stream, DumpOpts,
+  prettyPrintRegisterOp(/*U=*/nullptr, Stream, DumpOpts, Opcode, Operands);
-                                                Opcode, Operands);
   return Stream.str();
 }
 

llvm/lib/ProfileData/CMakeLists.txt

@@ -35,6 +35,7 @@ add_llvm_component_library(LLVMProfileData
   Demangle
   Symbolize
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   TargetParser
   )
 

llvm/lib/ProfileData/InstrProfCorrelator.cpp

@@ -10,10 +10,10 @@
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Format.h"

llvm/tools/dsymutil/CMakeLists.txt

@@ -15,6 +15,7 @@ set(LLVM_LINK_COMPONENTS
   DWARFLinkerClassic
   DWARFLinkerParallel
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   MC
   Object
   Option

llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

@@ -39,10 +39,10 @@
 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCCodeEmitter.h"

llvm/tools/llvm-dwarfdump/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(LLVM_LINK_COMPONENTS
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   AllTargetsDescs
   AllTargetsInfos
   MC

llvm/tools/llvm-dwarfdump/Statistics.cpp

@@ -12,7 +12,7 @@
 #include "llvm/ADT/StringSet.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/JSON.h"
 

llvm/tools/llvm-dwarfutil/CMakeLists.txt

@@ -11,6 +11,7 @@ set(LLVM_LINK_COMPONENTS
   DWARFLinkerClassic
   DWARFLinkerParallel
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   MC
   ObjCopy
   Object

llvm/tools/llvm-dwarfutil/DebugInfoLinker.cpp

@@ -13,7 +13,7 @@
 #include "llvm/DWARFLinker/Classic/DWARFStreamer.h"
 #include "llvm/DWARFLinker/Parallel/DWARFLinker.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Object/ObjectFile.h"
 #include <memory>
 #include <vector>

llvm/tools/llvm-objdump/CMakeLists.txt

@@ -5,6 +5,7 @@ set(LLVM_LINK_COMPONENTS
   BinaryFormat
   DebugInfoBTF
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   Demangle
   MC
   MCDisassembler

llvm/tools/llvm-objdump/SourcePrinter.cpp

@@ -15,7 +15,8 @@
 #include "SourcePrinter.h"
 #include "llvm-objdump.h"
 #include "llvm/ADT/SmallSet.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/Support/FormatVariadic.h"
 
 #define DEBUG_TYPE "objdump"
@@ -45,7 +46,7 @@ void LiveVariable::print(raw_ostream &OS, const MCRegisterInfo &MRI) const {
     return {};
   };
 
-  DWARFExpressionPrinter::printCompact(&Expression, OS, GetRegName);
+  printDwarfExpressionCompact(&Expression, OS, GetRegName);
 }
 
 void LiveVariablePrinter::addVariable(DWARFDie FuncDie, DWARFDie VarDie) {

llvm/unittests/DebugInfo/DWARF/CMakeLists.txt

@@ -4,6 +4,7 @@ set(LLVM_LINK_COMPONENTS
   BinaryFormat
   CodeGenTypes
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   MC
   Object
   ObjectYAML

llvm/unittests/DebugInfo/DWARF/DWARFExpressionCompactPrinterTest.cpp

@@ -10,7 +10,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpressionPrinter.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/TargetRegistry.h"
@@ -70,7 +71,7 @@ void DWARFExpressionCompactPrinterTest::TestExprPrinter(
     return {};
   };
 
-  DWARFExpressionPrinter::printCompact(&Expr, OS, GetRegName);
+  printDwarfExpressionCompact(&Expr, OS, GetRegName);
   EXPECT_EQ(OS.str(), Expected);
 }
 

llvm/unittests/DebugInfo/DWARF/DWARFExpressionCopyBytesTest.cpp

@@ -11,7 +11,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
-#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/LowLevel/DWARFExpression.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCCodeEmitter.h"

utils/bazel/llvm-project-overlay/bolt/BUILD.bazel

@@ -106,6 +106,7 @@ cc_library(
         "//llvm:DWARFLinker",
         "//llvm:DWP",
         "//llvm:DebugInfoDWARF",
+        "//llvm:DebugInfoDWARFLowLevel",
         "//llvm:Demangle",
         "//llvm:JITLink",
         "//llvm:MC",
@@ -296,6 +297,7 @@ cc_library(
         "//llvm:BinaryFormat",
         "//llvm:CodeGen",
         "//llvm:DebugInfoDWARF",
+        "//llvm:DebugInfoDWARFLowLevel",
         "//llvm:Demangle",
         "//llvm:ExecutionEngine",
         "//llvm:MC",

utils/bazel/llvm-project-overlay/llvm/BUILD.bazel

@@ -493,6 +493,7 @@ cc_library(
         ":DebugInfo",
         ":DebugInfoCodeView",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":DebugInfoPDB",
         ":Demangle",
         ":MC",
@@ -572,6 +573,7 @@ cc_library(
     deps = [
         ":BinaryFormat",
         ":DebugInfo",
+        ":DebugInfoDWARFLowLevel",
         ":MC",
         ":Object",
         ":Support",
@@ -579,6 +581,20 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "DebugInfoDWARFLowLevel",
+    srcs = glob([
+        "lib/DebugInfo/DWARF/LowLevel/*.cpp",
+    ]),
+    hdrs = glob(["include/llvm/DebugInfo/DWARF/LowLevel/*.h"]),
+    copts = llvm_copts,
+    deps = [
+        ":BinaryFormat",
+        ":Support",
+        ":TargetParser",
+    ],
+)
+
 cc_library(
     name = "DebugInfoGSYM",
     srcs = glob([
@@ -1163,6 +1179,7 @@ cc_library(
         ":Core",
         ":DebugInfo",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":Demangle",
         ":Object",
         ":Support",
@@ -2090,6 +2107,7 @@ cc_library(
         ":Core",
         ":DebugInfoCodeView",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":IPO",
         ":IRPrinter",
         ":Instrumentation",
@@ -3231,6 +3249,7 @@ cc_library(
         ":CodeGenTypes",
         ":DWARFLinkerBase",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":MC",
         ":Support",
         ":Target",
@@ -3249,6 +3268,7 @@ cc_library(
         ":BinaryFormat",
         ":CodeGen",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":Support",
         ":Target",
     ],
@@ -3549,6 +3569,7 @@ cc_library(
         ":DWARFLinkerParallel",
         ":DebugInfo",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":DsymutilTableGen",
         ":MC",
         ":Object",
@@ -3966,6 +3987,7 @@ cc_binary(
         ":BinaryFormat",
         ":DebugInfo",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":MC",
         ":Object",
         ":Support",
@@ -3997,6 +4019,7 @@ cc_binary(
         ":DWARFLinker",
         ":DWARFLinkerParallel",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":DwarfutilOptionsTableGen",
         ":MC",
         ":ObjCopy",
@@ -4614,6 +4637,7 @@ cc_library(
         ":DebugInfo",
         ":DebugInfoBTF",
         ":DebugInfoDWARF",
+        ":DebugInfoDWARFLowLevel",
         ":Debuginfod",
         ":Demangle",
         ":MC",