Reapply#4 "[RemoveDIs] Load into new debug info format by default in LLVM (#89799)"

Reapplies commit c5aeca73 (and its followup commit 21396be8), which were
reverted due to missing functionality in MLIR and Flang regarding printing
debug records. This has now been added in commit 08aa511, along with support
for printing debug records in flang.

This reverts commit 2dc2290860355dd2bac3b655eea895fe30fde257.

6 files changed, 26 insertions, 24 deletions

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index f0fde9a..eb1e3e4 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -74,23 +74,6 @@ static std::string getTypeString(Type *T) {
   return Tmp.str();
 }
 
-// Whatever debug info format we parsed, we should convert to the expected debug
-// info format immediately afterwards.
-bool LLParser::finalizeDebugInfoFormat(Module *M) {
-  // We should have already returned an error if we observed both intrinsics and
-  // records in this IR.
-  assert(!(SeenNewDbgInfoFormat && SeenOldDbgInfoFormat) &&
-         "Mixed debug intrinsics/records seen without a parsing error?");
-  if (PreserveInputDbgFormat == cl::boolOrDefault::BOU_TRUE) {
-    UseNewDbgInfoFormat = SeenNewDbgInfoFormat;
-    WriteNewDbgInfoFormatToBitcode = SeenNewDbgInfoFormat;
-    WriteNewDbgInfoFormat = SeenNewDbgInfoFormat;
-  } else if (M) {
-    M->setIsNewDbgInfoFormat(false);
-  }
-  return false;
-}
-
 /// Run: module ::= toplevelentity*
 bool LLParser::Run(bool UpgradeDebugInfo,
                    DataLayoutCallbackTy DataLayoutCallback) {
@@ -108,7 +91,7 @@ bool LLParser::Run(bool UpgradeDebugInfo,
   }
 
   return parseTopLevelEntities() || validateEndOfModule(UpgradeDebugInfo) ||
-         validateEndOfIndex() || finalizeDebugInfoFormat(M);
+         validateEndOfIndex();
 }
 
 bool LLParser::parseStandaloneConstantValue(Constant *&C,
@@ -207,6 +190,18 @@ void LLParser::dropUnknownMetadataReferences() {
 bool LLParser::validateEndOfModule(bool UpgradeDebugInfo) {
   if (!M)
     return false;
+
+  // We should have already returned an error if we observed both intrinsics and
+  // records in this IR.
+  assert(!(SeenNewDbgInfoFormat && SeenOldDbgInfoFormat) &&
+         "Mixed debug intrinsics/records seen without a parsing error?");
+  if (PreserveInputDbgFormat == cl::boolOrDefault::BOU_TRUE) {
+    UseNewDbgInfoFormat = SeenNewDbgInfoFormat;
+    WriteNewDbgInfoFormatToBitcode = SeenNewDbgInfoFormat;
+    WriteNewDbgInfoFormat = SeenNewDbgInfoFormat;
+    M->setNewDbgInfoFormatFlag(SeenNewDbgInfoFormat);
+  }
+
   // Handle any function attribute group forward references.
   for (const auto &RAG : ForwardRefAttrGroups) {
     Value *V = RAG.first;
@@ -439,6 +434,9 @@ bool LLParser::validateEndOfModule(bool UpgradeDebugInfo) {
   UpgradeModuleFlags(*M);
   UpgradeSectionAttributes(*M);
 
+  if (PreserveInputDbgFormat != cl::boolOrDefault::BOU_TRUE)
+    M->setIsNewDbgInfoFormat(UseNewDbgInfoFormat);
+
   if (!Slots)
     return false;
   // Initialize the slot mapping.
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 4ad3a2e..af5d689 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4358,7 +4358,7 @@ Error BitcodeReader::parseModule(uint64_t ResumeBit,
   if (PreserveInputDbgFormat != cl::boolOrDefault::BOU_TRUE) {
     TheModule->IsNewDbgInfoFormat =
         UseNewDbgInfoFormat &&
-        LoadBitcodeIntoNewDbgInfoFormat == cl::boolOrDefault::BOU_TRUE;
+        LoadBitcodeIntoNewDbgInfoFormat != cl::boolOrDefault::BOU_FALSE;
   }
 
   this->ValueTypeCallback = std::move(Callbacks.ValueType);
diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index 29f2cbf..aea9425 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -181,7 +181,7 @@ template class llvm::SymbolTableListTraits<Instruction,
 BasicBlock::BasicBlock(LLVMContext &C, const Twine &Name, Function *NewParent,
                        BasicBlock *InsertBefore)
     : Value(Type::getLabelTy(C), Value::BasicBlockVal),
-      IsNewDbgInfoFormat(false), Parent(nullptr) {
+      IsNewDbgInfoFormat(UseNewDbgInfoFormat), Parent(nullptr) {
 
   if (NewParent)
     insertInto(NewParent, InsertBefore);
diff --git a/llvm/lib/IR/DebugProgramInstruction.cpp b/llvm/lib/IR/DebugProgramInstruction.cpp
index fbca7cd..9a4926c 100644
--- a/llvm/lib/IR/DebugProgramInstruction.cpp
+++ b/llvm/lib/IR/DebugProgramInstruction.cpp
@@ -366,8 +366,8 @@ void DbgVariableRecord::setKillLocation() {
 }
 
 bool DbgVariableRecord::isKillLocation() const {
-  return (getNumVariableLocationOps() == 0 &&
-          !getExpression()->isComplex()) ||
+  return (!hasArgList() && isa<MDNode>(getRawLocation())) ||
+         (getNumVariableLocationOps() == 0 && !getExpression()->isComplex()) ||
          any_of(location_ops(), [](Value *V) { return isa<UndefValue>(V); });
 }
 
diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index 3f73502..9360e6d 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -83,6 +83,8 @@ static cl::opt<int> NonGlobalValueMaxNameSize(
     "non-global-value-max-name-size", cl::Hidden, cl::init(1024),
     cl::desc("Maximum size for the name of non-global values."));
 
+extern cl::opt<bool> UseNewDbgInfoFormat;
+
 void Function::convertToNewDbgValues() {
   IsNewDbgInfoFormat = true;
   for (auto &BB : *this) {
@@ -441,7 +443,7 @@ Function::Function(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace,
     : GlobalObject(Ty, Value::FunctionVal,
                    OperandTraits<Function>::op_begin(this), 0, Linkage, name,
                    computeAddrSpace(AddrSpace, ParentModule)),
-      NumArgs(Ty->getNumParams()), IsNewDbgInfoFormat(false) {
+      NumArgs(Ty->getNumParams()), IsNewDbgInfoFormat(UseNewDbgInfoFormat) {
   assert(FunctionType::isValidReturnType(getReturnType()) &&
          "invalid return type");
   setGlobalObjectSubClassData(0);
diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index f97dd18..55c282c 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -54,6 +54,8 @@
 
 using namespace llvm;
 
+extern cl::opt<bool> UseNewDbgInfoFormat;
+
 //===----------------------------------------------------------------------===//
 // Methods to implement the globals and functions lists.
 //
@@ -72,7 +74,7 @@ template class llvm::SymbolTableListTraits<GlobalIFunc>;
 Module::Module(StringRef MID, LLVMContext &C)
     : Context(C), ValSymTab(std::make_unique<ValueSymbolTable>(-1)),
       ModuleID(std::string(MID)), SourceFileName(std::string(MID)), DL(""),
-      IsNewDbgInfoFormat(false) {
+      IsNewDbgInfoFormat(UseNewDbgInfoFormat) {
   Context.addModule(this);
 }