[LLVM] Add a new attribute optdebug

Author: gmh5225

llvm/include/llvm/Bitcode/LLVMBitCodes.h

@@ -721,6 +721,7 @@ enum AttributeKindCodes {
   ATTR_KIND_HAS_CXXSEH = 93,
   ATTR_KIND_IS_SEH_FILTER_FUNCTION = 94,
   ATTR_KIND_IS_SEH_FINALLY_FUNCTION = 95,
+  ATTR_KIND_OPTIMIZE_FOR_DEBUGGING = 96,
 };
 
 enum ComdatSelectionKindCodes {

llvm/include/llvm/IR/Attributes.td

@@ -200,6 +200,9 @@ def NoSanitizeCoverage : EnumAttr<"nosanitize_coverage", [FnAttr]>;
 /// Null pointer in address space zero is valid.
 def NullPointerIsValid : EnumAttr<"null_pointer_is_valid", [FnAttr]>;
 
+/// Select optimizations that give decent debug info.
+def OptimizeForDebugging : EnumAttr<"optdebug", [FnAttr]>;
+
 /// Select optimizations for best fuzzing signal.
 def OptForFuzzing : EnumAttr<"optforfuzzing", [FnAttr]>;
 

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -2072,6 +2072,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
     return Attribute::IsSEHFilterFunction;
   case bitc::ATTR_KIND_IS_SEH_FINALLY_FUNCTION:
     return Attribute::IsSEHFinallyFunction;
+  case bitc::ATTR_KIND_OPTIMIZE_FOR_DEBUGGING:
+    return Attribute::OptimizeForDebugging;
   }
 }
 

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -844,6 +844,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
     return bitc::ATTR_KIND_IS_SEH_FILTER_FUNCTION;
   case Attribute::IsSEHFinallyFunction:
     return bitc::ATTR_KIND_IS_SEH_FINALLY_FUNCTION;
+  case Attribute::OptimizeForDebugging:
+    return bitc::ATTR_KIND_OPTIMIZE_FOR_DEBUGGING;
   }
 
   llvm_unreachable("Trying to encode unknown attribute");

llvm/lib/Transforms/Utils/CodeExtractor.cpp

@@ -941,6 +941,7 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
       case Attribute::NoSanitizeBounds:
       case Attribute::NoSanitizeCoverage:
       case Attribute::NullPointerIsValid:
+      case Attribute::OptimizeForDebugging:
       case Attribute::OptForFuzzing:
       case Attribute::OptimizeNone:
       case Attribute::OptimizeForSize: