[DebugInfo][RemoveDIs] Eliminate another debug-info variation flag (#133917)

The "preserve input debug-info format" flag allowed some tooling to opt
into not seeing the new debug records yet, and to not autoupgrade. This
was good at the time, but un-necessary now that we'll be ditching
intrinsics shortly.

It also hides errors now: verify-uselistorder was hardcoding this flag
to on, and as a result it hasn't seen debug records before. Thus, we
missed a uselistorder variation: constant-expressions such as GEPs can
be contained within debug records and completely isolated from the value
hierachy, see the metadata-use-uselistorder.ll test. These Values didn't
get ordered, but were legitimate uses of constants like "i64 0", and we
now run into difficulty handling that. The patch to AsmWriter seeks
Values to order even through debug-info now.

Finally there are a few intrinsics-tests relying on this flag that we
can just delete, such as one in llvm-reduce and another few in the
LocalTest unit tests. For the fast-isel test, it was added in
https://reviews.llvm.org/D67703 explicitly for checking the size of
blocks without debug-info and in 1525abb the codepath it tests moved
towards being sunsetted. It'll be totally redundant once RemoveDIs is on
permanently.

Note that there's now no explicit test for the textual-IR autoupgrade
path. I submit that we can rely on the thousands of .ll files where
we've only been bothered to update the outputs, not the inputs, to debug
records.

Author: jmorse

llvm/lib/AsmParser/LLParser.cpp

@@ -64,7 +64,6 @@ static cl::opt<bool> AllowIncompleteIR(
         "metadata will be dropped)"));
 
 extern llvm::cl::opt<bool> UseNewDbgInfoFormat;
-extern cl::opt<cl::boolOrDefault> PreserveInputDbgFormat;
 
 static std::string getTypeString(Type *T) {
   std::string Result;
@@ -209,10 +208,6 @@ bool LLParser::validateEndOfModule(bool UpgradeDebugInfo) {
   // records in this IR.
   assert(!(SeenNewDbgInfoFormat && SeenOldDbgInfoFormat) &&
          "Mixed debug intrinsics/records seen without a parsing error?");
-  if (PreserveInputDbgFormat == cl::boolOrDefault::BOU_TRUE) {
-    UseNewDbgInfoFormat = SeenNewDbgInfoFormat;
-    M->setNewDbgInfoFormatFlag(SeenNewDbgInfoFormat);
-  }
 
   // Handle any function attribute group forward references.
   for (const auto &RAG : ForwardRefAttrGroups) {
@@ -447,8 +442,7 @@ bool LLParser::validateEndOfModule(bool UpgradeDebugInfo) {
   UpgradeNVVMAnnotations(*M);
   UpgradeSectionAttributes(*M);
 
-  if (PreserveInputDbgFormat != cl::boolOrDefault::BOU_TRUE)
-    M->setIsNewDbgInfoFormat(UseNewDbgInfoFormat);
+  M->setIsNewDbgInfoFormat(UseNewDbgInfoFormat);
 
   if (!Slots)
     return false;

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -103,7 +103,6 @@ static cl::opt<bool> ExpandConstantExprs(
         "Expand constant expressions to instructions for testing purposes"));
 
 extern cl::opt<bool> UseNewDbgInfoFormat;
-extern cl::opt<cl::boolOrDefault> PreserveInputDbgFormat;
 
 namespace {
 
@@ -3953,11 +3952,7 @@ Error BitcodeReader::globalCleanup() {
   for (Function &F : *TheModule) {
     MDLoader->upgradeDebugIntrinsics(F);
     Function *NewFn;
-    // If PreserveInputDbgFormat=true, then we don't know whether we want
-    // intrinsics or records, and we won't perform any conversions in either
-    // case, so don't upgrade intrinsics to records.
-    if (UpgradeIntrinsicFunction(
-            &F, NewFn, PreserveInputDbgFormat != cl::boolOrDefault::BOU_TRUE))
+    if (UpgradeIntrinsicFunction(&F, NewFn))
       UpgradedIntrinsics[&F] = NewFn;
     // Look for functions that rely on old function attribute behavior.
     UpgradeFunctionAttributes(F);
@@ -7002,37 +6997,9 @@ Error BitcodeReader::materialize(GlobalValue *GV) {
   F->setIsMaterializable(false);
 
   // All parsed Functions should load into the debug info format dictated by the
-  // Module, unless we're attempting to preserve the input debug info format.
+  // Module.
   if (SeenDebugIntrinsic && SeenDebugRecord)
     return error("Mixed debug intrinsics and debug records in bitcode module!");
-  if (PreserveInputDbgFormat == cl::boolOrDefault::BOU_TRUE) {
-    bool SeenAnyDebugInfo = SeenDebugIntrinsic || SeenDebugRecord;
-    bool NewDbgInfoFormatDesired =
-        SeenAnyDebugInfo ? SeenDebugRecord : F->getParent()->IsNewDbgInfoFormat;
-    if (SeenAnyDebugInfo) {
-      UseNewDbgInfoFormat = SeenDebugRecord;
-    }
-    // If the module's debug info format doesn't match the observed input
-    // format, then set its format now; we don't need to call the conversion
-    // function because there must be no existing intrinsics to convert.
-    // Otherwise, just set the format on this function now.
-    if (NewDbgInfoFormatDesired != F->getParent()->IsNewDbgInfoFormat)
-      F->getParent()->setNewDbgInfoFormatFlag(NewDbgInfoFormatDesired);
-    else
-      F->setNewDbgInfoFormatFlag(NewDbgInfoFormatDesired);
-  } else {
-    // If we aren't preserving formats, we use the Module flag to get our
-    // desired format instead of reading flags, in case we are lazy-loading and
-    // the format of the module has been changed since it was set by the flags.
-    // We only need to convert debug info here if we have debug records but
-    // desire the intrinsic format; everything else is a no-op or handled by the
-    // autoupgrader.
-    bool ModuleIsNewDbgInfoFormat = F->getParent()->IsNewDbgInfoFormat;
-    if (ModuleIsNewDbgInfoFormat || !SeenDebugRecord)
-      F->setNewDbgInfoFormatFlag(ModuleIsNewDbgInfoFormat);
-    else
-      F->setIsNewDbgInfoFormat(ModuleIsNewDbgInfoFormat);
-  }
 
   if (StripDebugInfo)
     stripDebugInfo(*F);

llvm/lib/IR/AsmWriter.cpp

@@ -140,6 +140,20 @@ static void orderValue(const Value *V, OrderMap &OM) {
 static OrderMap orderModule(const Module *M) {
   OrderMap OM;
 
+  auto orderConstantValue = [&OM](const Value *V) {
+    if (isa<Constant>(V) || isa<InlineAsm>(V))
+      orderValue(V, OM);
+  };
+
+  auto OrderConstantFromMetadata = [&](Metadata *MD) {
+    if (const auto *VAM = dyn_cast<ValueAsMetadata>(MD)) {
+      orderConstantValue(VAM->getValue());
+    } else if (const auto *AL = dyn_cast<DIArgList>(MD)) {
+      for (const auto *VAM : AL->getArgs())
+        orderConstantValue(VAM->getValue());
+    }
+  };
+
   for (const GlobalVariable &G : M->globals()) {
     if (G.hasInitializer())
       if (!isa<GlobalValue>(G.getInitializer()))
@@ -171,6 +185,16 @@ static OrderMap orderModule(const Module *M) {
     for (const BasicBlock &BB : F) {
       orderValue(&BB, OM);
       for (const Instruction &I : BB) {
+        // Debug records can contain Value references, that can then contain
+        // Values disconnected from the rest of the Value hierachy, if wrapped
+        // in some kind of constant-expression. Find and order any Values that
+        // are wrapped in debug-info.
+        for (DbgVariableRecord &DVR : filterDbgVars(I.getDbgRecordRange())) {
+          OrderConstantFromMetadata(DVR.getRawLocation());
+          if (DVR.isDbgAssign())
+            OrderConstantFromMetadata(DVR.getRawAddress());
+        }
+
         for (const Value *Op : I.operands()) {
           Op = skipMetadataWrapper(Op);
           if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||

llvm/lib/IR/BasicBlock.cpp

@@ -36,13 +36,6 @@ cl::opt<bool> UseNewDbgInfoFormat(
              "eliminating intrinsics. Has no effect if "
              "--preserve-input-debuginfo-format=true."),
     cl::init(true));
-cl::opt<cl::boolOrDefault> PreserveInputDbgFormat(
-    "preserve-input-debuginfo-format", cl::Hidden,
-    cl::desc("When set to true, IR files will be processed and printed in "
-             "their current debug info format, regardless of default behaviour "
-             "or other flags passed. Has no effect if input IR does not "
-             "contain debug records or intrinsics. Ignored in llvm-link, "
-             "llvm-lto, and llvm-lto2."));
 
 DbgMarker *BasicBlock::createMarker(Instruction *I) {
   assert(IsNewDbgInfoFormat &&

llvm/test/Assembler/2010-02-05-FunctionLocalMetadataBecomesNull.ll

@@ -13,7 +13,7 @@ target triple = "x86_64-apple-darwin10.2"
 define i32 @main() nounwind readonly !dbg !1 {
   %diff1 = alloca i64                             ; <ptr> [#uses=2]
 ; CHECK: #dbg_value(i64 72,
-  call void @llvm.dbg.declare(metadata ptr %diff1, metadata !0, metadata !DIExpression()), !dbg !DILocation(scope: !1)
+    #dbg_declare(ptr %diff1, !0, !DIExpression(), !DILocation(scope: !1))
   store i64 72, ptr %diff1, align 8
   %v1 = load ptr, ptr @TestArrayPtr, align 8 ; <ptr> [#uses=1]
   %v2 = ptrtoint ptr %v1 to i64 ; <i64> [#uses=1]

llvm/test/Assembler/DIDefaultTemplateParam.ll

@@ -15,8 +15,8 @@ entry:
   %f1 = alloca %class.foo, align 1
   %f2 = alloca %class.foo.0, align 1
   store i32 0, ptr %retval, align 4
-  call void @llvm.dbg.declare(metadata ptr %f1, metadata !11, metadata !DIExpression()), !dbg !16
-  call void @llvm.dbg.declare(metadata ptr %f2, metadata !17, metadata !DIExpression()), !dbg !23
+    #dbg_declare(ptr %f1, !11, !DIExpression(), !16)
+    #dbg_declare(ptr %f2, !17, !DIExpression(), !23)
   ret i32 0, !dbg !24
 }
 ; Function Attrs: nounwind readnone speculatable willreturn

llvm/test/Assembler/metadata-use-uselistorder.ll

@@ -7,6 +7,11 @@
 ; correctly preserved due to the uses in the dbg.value contant expressions not
 ; being considered, since they are wrapped in metadata.
 
+; With debug records (i.e., not with intrinsics) there's less chance of
+; debug-info affecting use-list order as it exists outside of the Value
+; hierachy. However, debug records still use ValueAsMetadata nodes, so this
+; test remains worthwhile.
+
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
@@ -16,21 +21,19 @@ target triple = "x86_64-unknown-linux-gnu"
 define void @foo() local_unnamed_addr !dbg !6 {
 entry:
   %0 = load i64, ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 4), align 16
-  call void @llvm.dbg.value(metadata ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 5), metadata !10, metadata !DIExpression()), !dbg !13
+    #dbg_value(ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 5), !10, !DIExpression(), !13)
   %1 = load i64, ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 6), align 16
-  call void @llvm.dbg.value(metadata ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 6), metadata !10, metadata !DIExpression()), !dbg !14
+    #dbg_value(ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 6), !10, !DIExpression(), !14)
+    #dbg_assign(i32 0, !10, !DIExpression(), !19, ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 6), !DIExpression(), !14)
   ret void
 }
 
 define void @bar() local_unnamed_addr !dbg !15 {
 entry:
-  call void @llvm.dbg.value(metadata ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 7), metadata !17, metadata !DIExpression()), !dbg !18
+    #dbg_value(ptr getelementptr inbounds ([10 x i64], ptr @global_arr, i64 0, i64 7), !17, !DIExpression(), !18)
   ret void
 }
 
-; Function Attrs: nounwind readnone speculatable
-declare void @llvm.dbg.value(metadata, metadata, metadata) #0
-
 attributes #0 = { nounwind readnone speculatable }
 
 !llvm.dbg.cu = !{!0}
@@ -56,3 +59,4 @@ attributes #0 = { nounwind readnone speculatable }
 !16 = !{!17}
 !17 = !DILocalVariable(name: "local2", scope: !15, file: !1, line: 13, type: !11)
 !18 = !DILocation(line: 14, column: 1, scope: !15)
+!19 = distinct !DIAssignID()

llvm/test/Bitcode/dbg-record-roundtrip.ll

@@ -1,12 +1,10 @@
 ;; Roundtrip tests.
 
-;; Tests that bitcode can be printed and interpreted by llvm-dis with non-intrinsic
-;; debug records -- llvm-as will autoupgrade.
 ; RUN: llvm-as %s -o - \
 ; RUN: | llvm-dis \
 ; RUN: | FileCheck %s --check-prefixes=RECORDS
 
-;; Check that verify-uselistorder passes regardless of input format.
+;; Check that verify-uselistorder passes with bitcode and textual IR.
 ; RUN: llvm-as %s -o - | verify-uselistorder
 ; RUN: verify-uselistorder %s
 
@@ -31,17 +29,18 @@ entry:
 ; RECORDS-NEXT: dbg_value(![[empty:[0-9]+]], ![[e]], !DIExpression(), ![[dbg]])
 ; RECORDS-NEXT: dbg_value(i32 poison, ![[e]], !DIExpression(), ![[dbg]])
 ; RECORDS-NEXT: dbg_value(i32 1, ![[f:[0-9]+]], !DIExpression(), ![[dbg]])
-  tail call void @llvm.dbg.value(metadata i32 %p, metadata !32, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.value(metadata !29, metadata !32, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.value(metadata i32 poison, metadata !32, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.value(metadata i32 1, metadata !33, metadata !DIExpression()), !dbg !19
+    #dbg_value(i32 %p, !32, !DIExpression(), !19)
+    #dbg_value(!29, !32, !DIExpression(), !19)
+    #dbg_value(i32 poison, !32, !DIExpression(), !19)
+    #dbg_value(i32 1, !33, !DIExpression(), !19)
 ;; Arglist with an argument, constant, local use before def, poison.
 ; RECORDS-NEXT: dbg_value(!DIArgList(i32 %p, i32 0, i32 %0, i32 poison), ![[f]], !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_plus, DW_OP_LLVM_arg, 2, DW_OP_LLVM_arg, 3, DW_OP_plus, DW_OP_minus), ![[dbg]])
-  tail call void @llvm.dbg.value(metadata !DIArgList(i32 %p, i32 0, i32 %0, i32 poison), metadata !33, metadata !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_plus, DW_OP_LLVM_arg, 2, DW_OP_LLVM_arg, 3, DW_OP_plus, DW_OP_minus)), !dbg !19
+    #dbg_value(!DIArgList(i32 %p, i32 0, i32 %0, i32 poison), !33, !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_plus, DW_OP_LLVM_arg, 2, DW_OP_LLVM_arg, 3, DW_OP_plus, DW_OP_minus), !19)
+
 ;; Check dbg.assign use before def (value, addr and ID). Check expression order too.
 ; RECORDS: dbg_assign(i32 %0, ![[i:[0-9]+]], !DIExpression(DW_OP_plus_uconst, 0),
 ; RECORDS-SAME:       ![[ID:[0-9]+]], ptr %a, !DIExpression(DW_OP_plus_uconst, 1), ![[dbg]])
-  tail call void @llvm.dbg.assign(metadata i32 %0, metadata !36, metadata !DIExpression(DW_OP_plus_uconst, 0), metadata !37, metadata ptr %a, metadata !DIExpression(DW_OP_plus_uconst, 1)), !dbg !19
+    #dbg_assign(i32 %0, !36, !DIExpression(DW_OP_plus_uconst, 0), !37, ptr %a, !DIExpression(DW_OP_plus_uconst, 1), !19)
   %a = alloca i32, align 4, !DIAssignID !37
 ; CHECK: %a = alloca i32, align 4, !DIAssignID ![[ID]]
 ;; Check dbg.declare configurations.
@@ -51,25 +50,25 @@ entry:
 ; RECORDS-NEXT: dbg_declare(ptr poison, ![[c:[0-9]+]], !DIExpression(), ![[dbg]])
 ; RECORDS-NEXT: dbg_declare(ptr null, ![[d:[0-9]+]], !DIExpression(), ![[dbg]])
 ; RECORDS-NEXT: dbg_declare(ptr @g, ![[h:[0-9]+]], !DIExpression(), ![[dbg]])
-  tail call void @llvm.dbg.declare(metadata ptr %a, metadata !17, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.declare(metadata !29, metadata !28, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.declare(metadata ptr poison, metadata !30, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.declare(metadata ptr null, metadata !31, metadata !DIExpression()), !dbg !19
-  tail call void @llvm.dbg.declare(metadata ptr @g, metadata !35, metadata !DIExpression()), !dbg !19
+    #dbg_declare(ptr %a, !17, !DIExpression(), !19)
+    #dbg_declare(!29, !28, !DIExpression(), !19)
+    #dbg_declare(ptr poison, !30, !DIExpression(), !19)
+    #dbg_declare(ptr null, !31, !DIExpression(), !19)
+    #dbg_declare(ptr @g, !35, !DIExpression(), !19)
 ;; Argument value dbg.declare.
 ; RECORDS: dbg_declare(ptr %storage, ![[g:[0-9]+]], !DIExpression(), ![[dbg]])
-  tail call void @llvm.dbg.declare(metadata ptr %storage, metadata !34, metadata !DIExpression()), !dbg !19
+    #dbg_declare(ptr %storage, !34, !DIExpression(), !19)
 ;; Use before def dbg.value.
 ; RECORDS: dbg_value(i32 %0, ![[e]], !DIExpression(), ![[dbg]])
-  tail call void @llvm.dbg.value(metadata i32 %0, metadata !32, metadata !DIExpression()), !dbg !19
+    #dbg_value(i32 %0, !32, !DIExpression(), !19)
   %0 = load i32, ptr @g, align 4, !dbg !20
 ;; Non-argument local value dbg.value.
 ; RECORDS: dbg_value(i32 %0, ![[e]], !DIExpression(), ![[dbg]])
-  tail call void @llvm.dbg.value(metadata i32 %0, metadata !32, metadata !DIExpression()), !dbg !19
+    #dbg_value(i32 %0, !32, !DIExpression(), !19)
   store i32 %0, ptr %a, align 4, !dbg !19
   %1 = load i32, ptr %a, align 4, !dbg !25
 ; RECORDS: dbg_label(![[label:[0-9]+]], ![[dbg]])
-  tail call void @llvm.dbg.label(metadata !38), !dbg !19
+    #dbg_label(!38, !19)
   ret i32 %1, !dbg !27
 }
 

llvm/test/CodeGen/AArch64/fast-isel-branch-uncond-debug.ll

@@ -1,7 +1,7 @@
 ; RUN: llvm-reduce %s -o %t --delta-passes=metadata --test %python --test-arg %p/Inputs/remove-metadata.py --abort-on-invalid-reduction
 ; RUN: FileCheck %s --input-file %t
 
-; CHECK: call void @llvm.dbg.declare{{.*}}, !dbg
+; CHECK: #dbg_declare
 ; CHECK: !llvm.dbg.cu = !{!0}
 ; CHECK-NOT: uninteresting
 

llvm/test/tools/llvm-reduce/debug-metadata-verifier.ll

@@ -130,7 +130,6 @@ static cl::opt<bool> IgnoreNonBitcode(
     cl::Hidden);
 
 extern cl::opt<bool> UseNewDbgInfoFormat;
-extern cl::opt<cl::boolOrDefault> PreserveInputDbgFormat;
 
 static ExitOnError ExitOnErr;
 
@@ -479,11 +478,6 @@ int main(int argc, char **argv) {
   cl::HideUnrelatedOptions({&LinkCategory, &getColorCategory()});
   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
 
-  // Since llvm-link collects multiple IR modules together, for simplicity's
-  // sake we disable the "PreserveInputDbgFormat" flag to enforce a single
-  // debug info format.
-  PreserveInputDbgFormat = cl::boolOrDefault::BOU_FALSE;
-
   LLVMContext Context;
   Context.setDiagnosticHandler(std::make_unique<LLVMLinkDiagnosticHandler>(),
                                true);

llvm/test/tools/llvm-reduce/remove-args-dbg-intrinsics.ll

@@ -264,8 +264,6 @@ static cl::opt<bool>
     LTOSaveBeforeOpt("lto-save-before-opt", cl::init(false),
                      cl::desc("Save the IR before running optimizations"));
 
-extern cl::opt<cl::boolOrDefault> PreserveInputDbgFormat;
-
 namespace {
 
 struct ModuleInfo {
@@ -1001,11 +999,6 @@ int main(int argc, char **argv) {
   cl::HideUnrelatedOptions({&LTOCategory, &getColorCategory()});
   cl::ParseCommandLineOptions(argc, argv, "llvm LTO linker\n");
 
-  // Since llvm-lto collects multiple IR modules together, for simplicity's sake
-  // we disable the "PreserveInputDbgFormat" flag to enforce a single debug info
-  // format.
-  PreserveInputDbgFormat = cl::boolOrDefault::BOU_FALSE;
-
   if (OptLevel < '0' || OptLevel > '3')
     error("optimization level must be between 0 and 3");