Revert "[llvm-reduce] Remove debug metadata elements"

[ellis]

Summary

This reverts commit 69549de865550e54983ed8d00009920184de47ff.

The change in D135237 can lead to verification failures like scope must have two or three operands.
The ongoing work in D132077 does something similar without these failures, so lets wait for that to land and revert this patch.

[aeubanks]

thanks, and sorry for the trouble

llvm/test/tools/llvm-reduce/Inputs/remove-metadata.py

+import sys
+
+input = open(sys.argv[1], "r")
+for line in input:
+  if "!interesting" in line:
+    sys.exit(0)
+
+sys.exit(1)

llvm/test/tools/llvm-reduce/remove-debug-info-nodes.ll

 ; Test that llvm-reduce can drop unneeded debug metadata nodes referenced by
 ; DICompileUnit and DISuprogram.
 ;
 ; RUN: llvm-reduce --delta-passes=metadata --test FileCheck --test-arg --check-prefixes=CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
 ; RUN: cat %t | FileCheck %s
 
 ; CHECK-INTERESTINGNESS: define void @test() !dbg
 ; CHECK-INTERESTINGNESS: !llvm.module.flags = !{
 
 ; CHECK-INTERESTINGNESS: !llvm.dbg.cu = !{[[CU:.+]]}
 
 ; CHECK-INTERESTINGNESS-DAG: [[CU]] = distinct !DICompileUnit(language: DW_LANG_C99,{{.*}}, retainedTypes: [[TYPES:![0-9]+]]
 ; CHECK-INTERESTINGNESS-DAG: [[TYPES]] = !{[[T0:![0-9]+]]
 ; CHECK-INTERESTINGNESS-DAG: [[T0]] = !DIBasicType(name: "unsigned int",
-; CHECK-INTERESTINGNESS-DAG: !DIGlobalVariable(
-; CHECK-INTERESTINGNESS-DAG: !DILocalVariable(name: "A"
-; CHECK-INTERESTINGNESS-DAG: !DILocalVariable(name: "B"
-; CHECK-INTERESTINGNESS-DAG: !DILocalVariable(name: "C"
 
 
 
 ; CHECK: define void @test() !dbg [[SUBPROG:![0-9]+]]
 ; CHECK: !llvm.module.flags = !{
 
 ; CHECK: !llvm.dbg.cu = !{[[CU:.+]]}
 

llvm/test/tools/llvm-reduce/remove-metadata-elements.ll

-; RUN: llvm-reduce %s -o %t --delta-passes=metadata --test FileCheck --test-arg %s --test-arg --input-file
-; RUN: FileCheck %s < %t --implicit-check-not="boring"
-
-; Test that debug metadata lists can be reduced by making sure debug info for
-; "boring" globals are removed.
-
-; $ cat a.c
-; int boringA, interesting, boringB;
-; $ clang a.c -g -S -emit-llvm -o -
-
-@A = dso_local global i32 0, align 4, !dbg !0
-@B = dso_local global i32 0, align 4, !dbg !5
-@C = dso_local global i32 0, align 4, !dbg !8
-
-!llvm.dbg.cu = !{!2}
-!llvm.module.flags = !{!10, !11, !12, !13, !14, !15, !16}
-
-!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
-!1 = distinct !DIGlobalVariable(name: "boringA", scope: !2, file: !3, line: 1, type: !7, isLocal: false, isDefinition: true)
-!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None)
-!3 = !DIFile(filename: "a.c", directory: "")
-!4 = !{!0, !5, !8}
-!5 = !DIGlobalVariableExpression(var: !6, expr: !DIExpression())
-; CHECK: !DIGlobalVariable(name: "interesting"
-!6 = distinct !DIGlobalVariable(name: "interesting", scope: !2, file: !3, line: 1, type: !7, isLocal: false, isDefinition: true)
-!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-!8 = !DIGlobalVariableExpression(var: !9, expr: !DIExpression())
-!9 = distinct !DIGlobalVariable(name: "boringB", scope: !2, file: !3, line: 1, type: !7, isLocal: false, isDefinition: true)
-!10 = !{i32 7, !"Dwarf Version", i32 5}
-!11 = !{i32 2, !"Debug Info Version", i32 3}
-!12 = !{i32 1, !"wchar_size", i32 4}
-!13 = !{i32 8, !"PIC Level", i32 2}
-!14 = !{i32 7, !"PIE Level", i32 2}
-!15 = !{i32 7, !"uwtable", i32 2}
-!16 = !{i32 7, !"frame-pointer", i32 2}

llvm/test/tools/llvm-reduce/remove-metadata.ll

 ; Test that llvm-reduce can remove uninteresting metadata from an IR file.
 ; The Metadata pass erases named & unnamed metadata nodes.
 ;
-; RUN: llvm-reduce %s -o %t --delta-passes=metadata --test FileCheck --test-arg %s --test-arg --input-file
-; RUN: FileCheck %s < %t
+; RUN: llvm-reduce --test %python --test-arg %p/Inputs/remove-metadata.py %s -o %t
+; RUN: cat %t | FileCheck -implicit-check-not=! %s
 
 @global = global i32 0, !dbg !0
 
 define void @main() !dbg !0 {
    ret void, !dbg !0
 }
 
 !uninteresting = !{!0}
-; CHECK: !interesting = !{![[I:[0-9]+]]}
+; CHECK: !interesting = !{!0}
 !interesting = !{!1}
 
 !0 = !{!"uninteresting"}
-; CHECK: ![[I]] = !{!"interesting"}
+; CHECK: !0 = !{!"interesting"}
 !1 = !{!"interesting"}

llvm/test/tools/llvm-reduce/remove-named-metadata-elements.ll

-; RUN: llvm-reduce %s -o %t --delta-passes=metadata --test FileCheck --test-arg %s --test-arg --input-file
-; RUN: FileCheck %s < %t --implicit-check-not="boring" --check-prefixes=CHECK,REDUCED
-
-; Test that we can remove elements from named metadata.
-
-!llvm.dbg.cu = !{!0, !1}
-; CHECK: !llvm.module.flags =
-; REDUCED-SAME: !{}
-!llvm.module.flags = !{!10, !11, !12, !13, !14, !15, !16}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, isOptimized: false, runtimeVersion: 0, emissionKind: NoDebug)
-!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, isOptimized: false, runtimeVersion: 0, emissionKind: NoDebug)
-; CHECK: !DIFile(filename: "interesting.c"
-!2 = !DIFile(filename: "interesting.c", directory: "")
-!3 = !DIFile(filename: "boring.c", directory: "")
-
-!10 = !{i32 7, !"Dwarf Version", i32 5}
-!11 = !{i32 2, !"Debug Info Version", i32 3}
-!12 = !{i32 1, !"wchar_size", i32 4}
-!13 = !{i32 8, !"PIC Level", i32 2}
-!14 = !{i32 7, !"PIE Level", i32 2}
-!15 = !{i32 7, !"uwtable", i32 2}
-!16 = !{i32 7, !"frame-pointer", i32 2}

llvm/tools/llvm-reduce/deltas/ReduceMetadata.cpp

 #include "llvm/IR/InstIterator.h"
 #include <vector>
 
 using namespace llvm;
 
 /// Removes all the Named and Unnamed Metadata Nodes, as well as any debug
 /// functions that aren't inside the desired Chunks.
 static void extractMetadataFromModule(Oracle &O, Module &Program) {
-  SmallSetVector<MDNode *, 8> NodesToVisit;
-
   // Get out-of-chunk Named metadata nodes
   SmallVector<NamedMDNode *> NamedNodesToDelete;
-  for (NamedMDNode &MD : Program.named_metadata()) {
-    if (O.shouldKeep()) {
-      for (auto *Op : MD.operands())
-        NodesToVisit.insert(Op);
-    } else {
+  for (NamedMDNode &MD : Program.named_metadata())
+    if (!O.shouldKeep())
       NamedNodesToDelete.push_back(&MD);
-    }
-  }
 
   for (NamedMDNode *NN : NamedNodesToDelete) {
     for (auto I : seq<unsigned>(0, NN->getNumOperands()))
       NN->setOperand(I, nullptr);
     NN->eraseFromParent();
   }
 
-  // Delete elements from named metadata lists
-  for (auto &NamedList : Program.named_metadata()) {
-    SmallVector<MDNode *> NewOperands;
-    for (auto *Op : NamedList.operands())
-      if (O.shouldKeep())
-        NewOperands.push_back(Op);
-    if (NewOperands.size() == NamedList.getNumOperands())
-      continue;
-    NamedList.clearOperands();
-    for (auto *Op : NewOperands)
-      NamedList.addOperand(Op);
-  }
-
   // Delete out-of-chunk metadata attached to globals.
   for (GlobalVariable &GV : Program.globals()) {
     SmallVector<std::pair<unsigned, MDNode *>> MDs;
     GV.getAllMetadata(MDs);
-    for (std::pair<unsigned, MDNode *> &MD : MDs) {
-      if (O.shouldKeep()) {
-        NodesToVisit.insert(MD.second);
-      } else {
+    for (std::pair<unsigned, MDNode *> &MD : MDs)
+      if (!O.shouldKeep())
         GV.setMetadata(MD.first, nullptr);
-      }
-    }
-  }
 
   for (Function &F : Program) {
     {
       SmallVector<std::pair<unsigned, MDNode *>> MDs;
       // Delete out-of-chunk metadata attached to functions.
       F.getAllMetadata(MDs);
-      for (std::pair<unsigned, MDNode *> &MD : MDs) {
-        if (O.shouldKeep()) {
-          NodesToVisit.insert(MD.second);
-        } else {
+      for (std::pair<unsigned, MDNode *> &MD : MDs)
+        if (!O.shouldKeep())
           F.setMetadata(MD.first, nullptr);
-        }
-      }
-    }
 
     // Delete out-of-chunk metadata attached to instructions.
     for (Instruction &I : instructions(F)) {
       SmallVector<std::pair<unsigned, MDNode *>> MDs;
       I.getAllMetadata(MDs);
-      for (std::pair<unsigned, MDNode *> &MD : MDs) {
-        if (O.shouldKeep()) {
-          NodesToVisit.insert(MD.second);
-        } else {
+      for (std::pair<unsigned, MDNode *> &MD : MDs)
+        if (!O.shouldKeep())
           I.setMetadata(MD.first, nullptr);
-        }
-      }
-    }
-  }
-
-  // Gather all metadata tuples and their parents
-  SmallVector<std::pair<MDNode *, unsigned>> OperandsOfTuples;
-  SmallSet<Metadata *, 8> VisitedNodes;
-  while (!NodesToVisit.empty()) {
-    auto *Node = NodesToVisit.pop_back_val();
-    if (!VisitedNodes.insert(Node).second)
-      continue;
-    for (auto I : seq<unsigned>(0, Node->getNumOperands())) {
-      auto *Op = Node->getOperand(I).get();
-      if (auto *MD = dyn_cast_or_null<MDNode>(Op))
-        NodesToVisit.insert(MD);
-      if (isa_and_nonnull<MDTuple>(Op))
-        OperandsOfTuples.push_back(std::make_pair(Node, I));
-    }
-  }
-
-  // Delete elements from metadata tuples
-  for (auto [Node, NodeOpID] : OperandsOfTuples) {
-    auto *Tuple = dyn_cast<MDTuple>(Node->getOperand(NodeOpID));
-    SmallVector<Metadata *> NewOperands;
-    for (auto &Op : Tuple->operands())
-      if (O.shouldKeep())
-        NewOperands.push_back(Op.get());
-    if (NewOperands.size() == Tuple->getNumOperands())
-      continue;
-    Node->replaceOperandWith(
-        NodeOpID, MDTuple::get(Tuple->getContext(), makeArrayRef(NewOperands)));
-  }
-}
 
 void llvm::reduceMetadataDeltaPass(TestRunner &Test) {
   outs() << "*** Reducing Metadata...\n";
   runDeltaPass(Test, extractMetadataFromModule);
   outs() << "----------------------------\n";
 }