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

This patch enables parsing and creating modules directly into the new
debug info format. Prior to this patch, all modules were constructed
with the old debug info format by default, and would be converted into
the new format just before running LLVM passes. This is an important
milestone, in that this means that every tool will now be exposed to
debug records, rather than those that run LLVM passes. As far as I've
tested, all LLVM tools/projects now either handle debug records, or
convert them to the old intrinsic format.

There are a few unit tests that need updating for this patch; these are
either cases of tests that previously needed to set the debug info
format to function, or tests that depend on the old debug info format in
some way. There should be no visible change in the output of any LLVM
tool as a result of this patch, although the likelihood of this patch
breaking downstream code means an NFC tag might be a little misleading,
if not technically incorrect:

This will probably break some downstream tools that don't already handle
debug records. If your downstream code breaks as a result of this
change, the simplest fix is to convert the module in question to the old
debug format before you process it, using
`Module::convertFromNewDbgValues()`. For more information about how to
handle debug records or about what has changed, see the migration
document:
  https://llvm.org/docs/RemoveDIsDebugInfo.html

3 files changed, 16 insertions, 24 deletions

diff --git a/llvm/unittests/IR/BasicBlockDbgInfoTest.cpp b/llvm/unittests/IR/BasicBlockDbgInfoTest.cpp
index f873bbd..26c00b8 100644
--- a/llvm/unittests/IR/BasicBlockDbgInfoTest.cpp
+++ b/llvm/unittests/IR/BasicBlockDbgInfoTest.cpp
@@ -72,8 +72,6 @@ TEST(BasicBlockDbgInfoTest, InsertAfterSelf) {
     !11 = !DILocation(line: 1, column: 1, scope: !6)
 )");
 
-  // Convert the module to "new" form debug-info.
-  M->convertToNewDbgValues();
   // Fetch the entry block.
   BasicBlock &BB = M->getFunction("f")->getEntryBlock();
 
@@ -104,8 +102,6 @@ TEST(BasicBlockDbgInfoTest, InsertAfterSelf) {
   auto Range2 = RetInst->getDbgRecordRange();
   EXPECT_EQ(std::distance(Range2.begin(), Range2.end()), 1u);
 
-  M->convertFromNewDbgValues();
-
   UseNewDbgInfoFormat = false;
 }
 
@@ -196,8 +192,6 @@ TEST(BasicBlockDbgInfoTest, MarkerOperations) {
 
   // Fetch the entry block,
   BasicBlock &BB = M->getFunction("f")->getEntryBlock();
-  // Convert the module to "new" form debug-info.
-  M->convertToNewDbgValues();
   EXPECT_EQ(BB.size(), 2u);
 
   // Fetch out our two markers,
@@ -332,8 +326,6 @@ TEST(BasicBlockDbgInfoTest, HeadBitOperations) {
   // Test that the movement of debug-data when using moveBefore etc and
   // insertBefore etc are governed by the "head" bit of iterators.
   BasicBlock &BB = M->getFunction("f")->getEntryBlock();
-  // Convert the module to "new" form debug-info.
-  M->convertToNewDbgValues();
 
   // Test that the head bit behaves as expected: it should be set when the
   // code wants the _start_ of the block, but not otherwise.
@@ -441,8 +433,6 @@ TEST(BasicBlockDbgInfoTest, InstrDbgAccess) {
   // Check that DbgVariableRecords can be accessed from Instructions without
   // digging into the depths of DbgMarkers.
   BasicBlock &BB = M->getFunction("f")->getEntryBlock();
-  // Convert the module to "new" form debug-info.
-  M->convertToNewDbgValues();
 
   Instruction *BInst = &*BB.begin();
   Instruction *CInst = BInst->getNextNode();
@@ -579,7 +569,6 @@ protected:
   void SetUp() override {
     UseNewDbgInfoFormat = true;
     M = parseIR(C, SpliceTestIR.c_str());
-    M->convertToNewDbgValues();
 
     BBEntry = &M->getFunction("f")->getEntryBlock();
     BBExit = BBEntry->getNextNode();
@@ -1219,7 +1208,6 @@ TEST(BasicBlockDbgInfoTest, DbgSpliceTrailing) {
 
   BasicBlock &Entry = M->getFunction("f")->getEntryBlock();
   BasicBlock &Exit = *Entry.getNextNode();
-  M->convertToNewDbgValues();
 
   // Begin by forcing entry block to have dangling DbgVariableRecord.
   Entry.getTerminator()->eraseFromParent();
@@ -1273,7 +1261,6 @@ TEST(BasicBlockDbgInfoTest, RemoveInstAndReinsert) {
 )");
 
   BasicBlock &Entry = M->getFunction("f")->getEntryBlock();
-  M->convertToNewDbgValues();
 
   // Fetch the relevant instructions from the converted function.
   Instruction *SubInst = &*Entry.begin();
@@ -1352,7 +1339,6 @@ TEST(BasicBlockDbgInfoTest, RemoveInstAndReinsertForOneDbgVariableRecord) {
 )");
 
   BasicBlock &Entry = M->getFunction("f")->getEntryBlock();
-  M->convertToNewDbgValues();
 
   // Fetch the relevant instructions from the converted function.
   Instruction *SubInst = &*Entry.begin();
@@ -1436,7 +1422,6 @@ TEST(BasicBlockDbgInfoTest, DbgSpliceToEmpty1) {
   Function &F = *M->getFunction("f");
   BasicBlock &Entry = F.getEntryBlock();
   BasicBlock &Exit = *Entry.getNextNode();
-  M->convertToNewDbgValues();
 
   // Begin by forcing entry block to have dangling DbgVariableRecord.
   Entry.getTerminator()->eraseFromParent();
@@ -1506,7 +1491,6 @@ TEST(BasicBlockDbgInfoTest, DbgSpliceToEmpty2) {
   Function &F = *M->getFunction("f");
   BasicBlock &Entry = F.getEntryBlock();
   BasicBlock &Exit = *Entry.getNextNode();
-  M->convertToNewDbgValues();
 
   // Begin by forcing entry block to have dangling DbgVariableRecord.
   Entry.getTerminator()->eraseFromParent();
@@ -1576,7 +1560,6 @@ TEST(BasicBlockDbgInfoTest, DbgMoveToEnd) {
   Function &F = *M->getFunction("f");
   BasicBlock &Entry = F.getEntryBlock();
   BasicBlock &Exit = *Entry.getNextNode();
-  M->convertToNewDbgValues();
 
   // Move the return to the end of the entry block.
   Instruction *Br = Entry.getTerminator();
diff --git a/llvm/unittests/IR/DebugInfoTest.cpp b/llvm/unittests/IR/DebugInfoTest.cpp
index d06b979..ef6aa7f 100644
--- a/llvm/unittests/IR/DebugInfoTest.cpp
+++ b/llvm/unittests/IR/DebugInfoTest.cpp
@@ -237,6 +237,9 @@ TEST(DbgVariableIntrinsic, EmptyMDIsKillLocation) {
 // Duplicate of above test, but in DbgVariableRecord representation.
 TEST(MetadataTest, DeleteInstUsedByDbgVariableRecord) {
   LLVMContext C;
+  bool OldDbgValueMode = UseNewDbgInfoFormat;
+  UseNewDbgInfoFormat = true;
+
   std::unique_ptr<Module> M = parseIR(C, R"(
     define i16 @f(i16 %a) !dbg !6 {
       %b = add i16 %a, 1, !dbg !11
@@ -262,10 +265,7 @@ TEST(MetadataTest, DeleteInstUsedByDbgVariableRecord) {
     !11 = !DILocation(line: 1, column: 1, scope: !6)
 )");
 
-  bool OldDbgValueMode = UseNewDbgInfoFormat;
-  UseNewDbgInfoFormat = true;
   Instruction &I = *M->getFunction("f")->getEntryBlock().getFirstNonPHI();
-  M->convertToNewDbgValues();
 
   // Find the DbgVariableRecords using %b.
   SmallVector<DbgValueInst *, 2> DVIs;
@@ -1044,9 +1044,8 @@ TEST(MetadataTest, ConvertDbgToDbgVariableRecord) {
 TEST(MetadataTest, DbgVariableRecordConversionRoutines) {
   LLVMContext C;
 
-  // For the purpose of this test, set and un-set the command line option
-  // corresponding to UseNewDbgInfoFormat.
-  UseNewDbgInfoFormat = true;
+  bool OldDbgValueMode = UseNewDbgInfoFormat;
+  UseNewDbgInfoFormat = false;
 
   std::unique_ptr<Module> M = parseIR(C, R"(
     define i16 @f(i16 %a) !dbg !6 {
@@ -1077,6 +1076,11 @@ TEST(MetadataTest, DbgVariableRecordConversionRoutines) {
     !11 = !DILocation(line: 1, column: 1, scope: !6)
 )");
 
+  // For the purpose of this test, set and un-set the command line option
+  // corresponding to UseNewDbgInfoFormat, but only after parsing, to ensure
+  // that the IR starts off in the old format.
+  UseNewDbgInfoFormat = true;
+
   // Check that the conversion routines and utilities between dbg.value
   // debug-info format and DbgVariableRecords works.
   Function *F = M->getFunction("f");
@@ -1181,7 +1185,7 @@ TEST(MetadataTest, DbgVariableRecordConversionRoutines) {
   EXPECT_EQ(DVI2->getVariable(), DLV2);
   EXPECT_EQ(DVI2->getExpression(), Expr2);
 
-  UseNewDbgInfoFormat = false;
+  UseNewDbgInfoFormat = OldDbgValueMode;
 }
 
 } // end namespace
diff --git a/llvm/unittests/IR/InstructionsTest.cpp b/llvm/unittests/IR/InstructionsTest.cpp
index b47c73f..6c4debf 100644
--- a/llvm/unittests/IR/InstructionsTest.cpp
+++ b/llvm/unittests/IR/InstructionsTest.cpp
@@ -31,6 +31,8 @@
 #include "gtest/gtest.h"
 #include <memory>
 
+extern llvm::cl::opt<llvm::cl::boolOrDefault> PreserveInputDbgFormat;
+
 namespace llvm {
 namespace {
 
@@ -1460,6 +1462,8 @@ TEST(InstructionsTest, GetSplat) {
 
 TEST(InstructionsTest, SkipDebug) {
   LLVMContext C;
+  cl::boolOrDefault OldDbgFormat = PreserveInputDbgFormat;
+  PreserveInputDbgFormat = cl::boolOrDefault::BOU_TRUE;
   std::unique_ptr<Module> M = parseIR(C,
                                       R"(
       declare void @llvm.dbg.value(metadata, metadata, metadata)
@@ -1495,6 +1499,7 @@ TEST(InstructionsTest, SkipDebug) {
 
   // After the terminator, there are no non-debug instructions.
   EXPECT_EQ(nullptr, Term->getNextNonDebugInstruction());
+  PreserveInputDbgFormat = OldDbgFormat;
 }
 
 TEST(InstructionsTest, PhiMightNotBeFPMathOperator) {