From fbdeb8cbc147f8f49fbd4bf23fae01bd142f0f5d Mon Sep 17 00:00:00 2001
From: Vladislav Dzhidzhoev <vdzhidzhoev@accesssoftek.com>
Date: Thu, 15 Jun 2023 18:04:32 +0200
Subject: Revert "[DebugMetadata][DwarfDebug] Fix DWARF emisson of
 function-local imported entities (3/7)"

This reverts commit d80fdc6fc1a6e717af1bcd7a7313e65de433ba85.
split-dwarf-local-impor3.ll fails because of an issue with
Dwo sections emission on Windows platform.
---
 llvm/lib/Bitcode/Reader/MetadataLoader.cpp | 84 ------------------------------
 1 file changed, 84 deletions(-)

(limited to 'llvm/lib/Bitcode/Reader/MetadataLoader.cpp')

diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index f13c26e..4b5cfed 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -15,7 +15,6 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLFunctionalExtras.h"
-#include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
@@ -54,7 +53,6 @@
 #include <deque>
 #include <iterator>
 #include <limits>
-#include <map>
 #include <optional>
 #include <string>
 #include <tuple>
@@ -465,9 +463,6 @@ class MetadataLoader::MetadataLoaderImpl {
   bool NeedUpgradeToDIGlobalVariableExpression = false;
   bool NeedDeclareExpressionUpgrade = false;
 
-  /// Map DILocalScope to the enclosing DISubprogram, if any.
-  DenseMap<DILocalScope *, DISubprogram *> ParentSubprogram;
-
   /// True if metadata is being parsed for a module being ThinLTO imported.
   bool IsImporting = false;
 
@@ -526,84 +521,6 @@ class MetadataLoader::MetadataLoaderImpl {
     }
   }
 
-  DISubprogram *findEnclosingSubprogram(DILocalScope *S) {
-    if (!S)
-      return nullptr;
-    if (auto *SP = ParentSubprogram[S]) {
-      return SP;
-    }
-
-    DILocalScope *InitialScope = S;
-    DenseSet<DILocalScope *> Visited;
-    while (S && !isa<DISubprogram>(S)) {
-      S = dyn_cast_or_null<DILocalScope>(S->getScope());
-      if (Visited.contains(S))
-        break;
-      Visited.insert(S);
-    }
-    ParentSubprogram[InitialScope] = llvm::dyn_cast_or_null<DISubprogram>(S);
-
-    return ParentSubprogram[InitialScope];
-  }
-
-  /// Move local imports from DICompileUnit's 'imports' field to
-  /// DISubprogram's retainedNodes.
-  void upgradeCULocals() {
-    if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu")) {
-      for (unsigned I = 0, E = CUNodes->getNumOperands(); I != E; ++I) {
-        auto *CU = dyn_cast<DICompileUnit>(CUNodes->getOperand(I));
-        if (!CU)
-          continue;
-
-        if (auto *RawImported = CU->getRawImportedEntities()) {
-          // Collect a set of imported entities to be moved.
-          SmallPtrSet<Metadata *, 8> EntitiesToRemove;
-          for (Metadata *Op : CU->getImportedEntities()->operands()) {
-            auto *IE = cast<DIImportedEntity>(Op);
-            if (auto *S = dyn_cast_or_null<DILocalScope>(IE->getScope())) {
-              EntitiesToRemove.insert(IE);
-            }
-          }
-
-          if (!EntitiesToRemove.empty()) {
-            // Make a new list of CU's 'imports'.
-            SmallVector<Metadata *> NewImports;
-            for (Metadata *Op : CU->getImportedEntities()->operands()) {
-              if (!EntitiesToRemove.contains(cast<DIImportedEntity>(Op))) {
-                NewImports.push_back(Op);
-              }
-            }
-
-            // Find DISubprogram corresponding to each entity.
-            std::map<DISubprogram *, SmallVector<Metadata *>> SPToEntities;
-            for (auto *I : EntitiesToRemove) {
-              auto *Entity = cast<DIImportedEntity>(I);
-              if (auto *SP = findEnclosingSubprogram(
-                      cast<DILocalScope>(Entity->getScope()))) {
-                SPToEntities[SP].push_back(Entity);
-              }
-            }
-
-            // Update DISubprograms' retainedNodes.
-            for (auto I = SPToEntities.begin(); I != SPToEntities.end(); ++I) {
-              auto *SP = I->first;
-              auto RetainedNodes = SP->getRetainedNodes();
-              SmallVector<Metadata *> MDs(RetainedNodes.begin(),
-                                          RetainedNodes.end());
-              MDs.append(I->second);
-              SP->replaceRetainedNodes(MDNode::get(Context, MDs));
-            }
-
-            // Remove entities with local scope from CU.
-            CU->replaceImportedEntities(MDTuple::get(Context, NewImports));
-          }
-        }
-      }
-    }
-
-    ParentSubprogram.clear();
-  }
-
   /// Remove a leading DW_OP_deref from DIExpressions in a dbg.declare that
   /// describes a function argument.
   void upgradeDeclareExpressions(Function &F) {
@@ -708,7 +625,6 @@ class MetadataLoader::MetadataLoaderImpl {
   void upgradeDebugInfo() {
     upgradeCUSubprograms();
     upgradeCUVariables();
-    upgradeCULocals();
   }
 
   void callMDTypeCallback(Metadata **Val, unsigned TypeID);
-- 
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