[llvm] 9583a3f - [AsmPrinter] Delete dead takeDeletedSymbsForFunction()

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2020-01-18T17:08:00-08:00
New Revision: 9583a3f2625818b78c0cf6d473cdedb9f23ad82c

URL: https://github.com/llvm/llvm-project/commit/9583a3f2625818b78c0cf6d473cdedb9f23ad82c
DIFF: https://github.com/llvm/llvm-project/commit/9583a3f2625818b78c0cf6d473cdedb9f23ad82c.diff

LOG: [AsmPrinter] Delete dead takeDeletedSymbsForFunction()

The code added in r98579 is dead now.

Added: 
    

Modified: 
    llvm/include/llvm/CodeGen/MachineModuleInfo.h
    llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
    llvm/lib/CodeGen/MachineModuleInfo.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/CodeGen/MachineModuleInfo.h b/llvm/include/llvm/CodeGen/MachineModuleInfo.h
index 6902dada2423..20025ab39d0e 100644
--- a/llvm/include/llvm/CodeGen/MachineModuleInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineModuleInfo.h
@@ -233,13 +233,6 @@ class MachineModuleInfo {
   /// to emit them as well, return the whole set.
   ArrayRef<MCSymbol *> getAddrLabelSymbolToEmit(const BasicBlock *BB);
 
-  /// If the specified function has had any references to address-taken blocks
-  /// generated, but the block got deleted, return the symbol now so we can
-  /// emit it.  This prevents emitting a reference to a symbol that has no
-  /// definition.
-  void takeDeletedSymbolsForFunction(const Function *F,
-                                     std::vector<MCSymbol*> &Result);
-
   /// \name Exception Handling
   /// \{
 

diff  --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 6f9aa4dd79fd..368a7975bbbc 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -715,16 +715,6 @@ void AsmPrinter::EmitFunctionHeader() {
   // their wild and crazy things as required.
   EmitFunctionEntryLabel();
 
-  // If the function had address-taken blocks that got deleted, then we have
-  // references to the dangling symbols.  Emit them at the start of the function
-  // so that we don't get references to undefined symbols.
-  std::vector<MCSymbol*> DeadBlockSyms;
-  MMI->takeDeletedSymbolsForFunction(&F, DeadBlockSyms);
-  for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
-    OutStreamer->AddComment("Address taken block that was later removed");
-    OutStreamer->EmitLabel(DeadBlockSyms[i]);
-  }
-
   if (CurrentFnBegin) {
     if (MAI->useAssignmentForEHBegin()) {
       MCSymbol *CurPos = OutContext.createTempSymbol();

diff  --git a/llvm/lib/CodeGen/MachineModuleInfo.cpp b/llvm/lib/CodeGen/MachineModuleInfo.cpp
index 0094a923e039..ce5961aba9a7 100644
--- a/llvm/lib/CodeGen/MachineModuleInfo.cpp
+++ b/llvm/lib/CodeGen/MachineModuleInfo.cpp
@@ -76,25 +76,11 @@ class MMIAddrLabelMap {
   /// we get notified if a block is deleted or RAUWd.
   std::vector<MMIAddrLabelMapCallbackPtr> BBCallbacks;
 
-  /// This is a per-function list of symbols whose corresponding BasicBlock got
-  /// deleted.  These symbols need to be emitted at some point in the file, so
-  /// AsmPrinter emits them after the function body.
-  DenseMap<AssertingVH<Function>, std::vector<MCSymbol*>>
-    DeletedAddrLabelsNeedingEmission;
-
 public:
   MMIAddrLabelMap(MCContext &context) : Context(context) {}
 
-  ~MMIAddrLabelMap() {
-    assert(DeletedAddrLabelsNeedingEmission.empty() &&
-           "Some labels for deleted blocks never got emitted");
-  }
-
   ArrayRef<MCSymbol *> getAddrLabelSymbolToEmit(BasicBlock *BB);
 
-  void takeDeletedSymbolsForFunction(Function *F,
-                                     std::vector<MCSymbol*> &Result);
-
   void UpdateForDeletedBlock(BasicBlock *BB);
   void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
 };
@@ -132,20 +118,6 @@ ArrayRef<MCSymbol *> MMIAddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) {
   return Entry.Symbols;
 }
 
-/// If we have any deleted symbols for F, return them.
-void MMIAddrLabelMap::
-takeDeletedSymbolsForFunction(Function *F, std::vector<MCSymbol*> &Result) {
-  DenseMap<AssertingVH<Function>, std::vector<MCSymbol*>>::iterator I =
-    DeletedAddrLabelsNeedingEmission.find(F);
-
-  // If there are no entries for the function, just return.
-  if (I == DeletedAddrLabelsNeedingEmission.end()) return;
-
-  // Otherwise, take the list.
-  std::swap(Result, I->second);
-  DeletedAddrLabelsNeedingEmission.erase(I);
-}
-
 void MMIAddrLabelMap::UpdateForDeletedBlock(BasicBlock *BB) {
   // If the block got deleted, there is no need for the symbol.  If the symbol
   // was already emitted, we can just forget about it, otherwise we need to
@@ -158,16 +130,8 @@ void MMIAddrLabelMap::UpdateForDeletedBlock(BasicBlock *BB) {
   assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) &&
          "Block/parent mismatch");
 
-  for (MCSymbol *Sym : Entry.Symbols) {
-    if (Sym->isDefined())
-      return;
-
-    // If the block is not yet defined, we need to emit it at the end of the
-    // function.  Add the symbol to the DeletedAddrLabelsNeedingEmission list
-    // for the containing Function.  Since the block is being deleted, its
-    // parent may already be removed, we have to get the function from 'Entry'.
-    DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
-  }
+  assert(llvm::all_of(Entry.Symbols, [](MCSymbol *Sym) {
+    return Sym->isDefined(); }));
 }
 
 void MMIAddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) {
@@ -252,15 +216,6 @@ MachineModuleInfo::getAddrLabelSymbolToEmit(const BasicBlock *BB) {
  return AddrLabelSymbols->getAddrLabelSymbolToEmit(const_cast<BasicBlock*>(BB));
 }
 
-void MachineModuleInfo::
-takeDeletedSymbolsForFunction(const Function *F,
-                              std::vector<MCSymbol*> &Result) {
-  // If no blocks have had their addresses taken, we're done.
-  if (!AddrLabelSymbols) return;
-  return AddrLabelSymbols->
-     takeDeletedSymbolsForFunction(const_cast<Function*>(F), Result);
-}
-
 /// \name Exception Handling
 /// \{