[NFC][DebugInfo][DWARF] Create new low-level dwarf library (#145081)

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.
    
I am happy to put it in another location, or to structure it differently
if that makes sense. Some have suggested in BinaryFormat, but it is not
a great fit there. But if that makes more sense to the reviewers, I can
do that.
 
Another possibility would be to use pass-through headers to allow
clients who don't care to depend only on DebugInfo/DWARF. This would be
a much less invasive change, and perhaps easier for clients. But also a
system that hides details.

Either way, I'm open.

1.
https://discourse.llvm.org/t/rfc-debuginfo-dwarf-refactor-into-to-lower-and-higher-level-libraries/86665/2

Author: Sterling-Augustine

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"

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(),
-                                        llvm::DIDumpOptions(), nullptr);
+    printDwarfExpression(&E, s.AsRawOstream(), 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);