[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

2 files changed, 4 insertions, 2 deletions

diff --git a/llvm/tools/llvm-objdump/CMakeLists.txt b/llvm/tools/llvm-objdump/CMakeLists.txt
index 0306736..7e3197f 100644
--- a/llvm/tools/llvm-objdump/CMakeLists.txt
+++ b/llvm/tools/llvm-objdump/CMakeLists.txt
@@ -5,6 +5,7 @@ set(LLVM_LINK_COMPONENTS
   BinaryFormat
   DebugInfoBTF
   DebugInfoDWARF
+  DebugInfoDWARFLowLevel
   Demangle
   MC
   MCDisassembler
diff --git a/llvm/tools/llvm-objdump/SourcePrinter.cpp b/llvm/tools/llvm-objdump/SourcePrinter.cpp
index bf33637..3630502 100644
--- a/llvm/tools/llvm-objdump/SourcePrinter.cpp
+++ b/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) {