Centralize the handling of unique ids for temporary labels.

Before this patch code wanting to create temporary labels for a given entity
(function, cu, exception range, etc) had to keep its own counter to have stable
symbol names.

createTempSymbol would still add a suffix to make sure a new symbol was always
returned, but it kept a single counter. Because of that, if we were to use
just createTempSymbol("cu_begin"), the label could change from cu_begin42 to
cu_begin43 because some other code started using temporary labels.

Simplify this by just keeping one counter per prefix and removing the various
specialized counters.

llvm-svn: 232535

6 files changed, 16 insertions, 31 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index c5075273f13..7de5e4f10f1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -103,7 +103,7 @@ static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &DL,
 AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
     : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
       OutContext(Streamer->getContext()), OutStreamer(*Streamer.release()),
-      LastMI(nullptr), LastFn(0), Counter(~0U), SetCounter(0) {
+      LastMI(nullptr), LastFn(0), Counter(~0U) {
   DD = nullptr;
   MMI = nullptr;
   LI = nullptr;
@@ -890,7 +890,7 @@ void AsmPrinter::EmitFunctionBody() {
   if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
       MAI->hasDotTypeDotSizeDirective()) {
     // Create a symbol for the end of function.
-    CurrentFnEnd = createTempSymbol("func_end", getFunctionNumber());
+    CurrentFnEnd = createTempSymbol("func_end");
     OutStreamer.EmitLabel(CurrentFnEnd);
   }
 
@@ -1133,7 +1133,7 @@ bool AsmPrinter::doFinalization(Module &M) {
 
 MCSymbol *AsmPrinter::getCurExceptionSym() {
   if (!CurExceptionSym)
-    CurExceptionSym = createTempSymbol("exception", getFunctionNumber());
+    CurExceptionSym = createTempSymbol("exception");
   return CurExceptionSym;
 }
 
@@ -1147,7 +1147,7 @@ void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
   bool NeedsLocalForSize = MAI->needsLocalForSize();
   if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
       NeedsLocalForSize) {
-    CurrentFnBegin = createTempSymbol("func_begin", getFunctionNumber());
+    CurrentFnBegin = createTempSymbol("func_begin");
     if (NeedsLocalForSize)
       CurrentFnSymForSize = CurrentFnBegin;
   }
@@ -1577,7 +1577,7 @@ void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
   }
 
   // Otherwise, emit with .set (aka assignment).
-  MCSymbol *SetLabel = createTempSymbol("set", SetCounter++);
+  MCSymbol *SetLabel = createTempSymbol("set");
   OutStreamer.EmitAssignment(SetLabel, Diff);
   OutStreamer.EmitSymbolValue(SetLabel, Size);
 }
@@ -2252,8 +2252,8 @@ void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
 // Symbol Lowering Routines.
 //===----------------------------------------------------------------------===//
 
-MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name, unsigned ID) const {
-  return OutContext.createTempSymbol(Name + Twine(ID));
+MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
+  return OutContext.createTempSymbol(Name, true);
 }
 
 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp
index 28cc41ca366..f64338ec832 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp
@@ -96,7 +96,7 @@ void DwarfAccelTable::FinalizeTable(AsmPrinter *Asm, StringRef Prefix) {
   for (size_t i = 0, e = Data.size(); i < e; ++i) {
     uint32_t bucket = Data[i]->HashValue % Header.bucket_count;
     Buckets[bucket].push_back(Data[i]);
-    Data[i]->Sym = Asm->createTempSymbol(Prefix, i);
+    Data[i]->Sym = Asm->createTempSymbol(Prefix);
   }
 
   // Sort the contents of the buckets by hash value so that hash
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index eff65255288..eee5fc537da 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -379,9 +379,7 @@ void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
   const MCSymbol *RangeSectionSym =
       TLOF.getDwarfRangesSection()->getBeginSymbol();
 
-  RangeSpanList List(
-      Asm->createTempSymbol("debug_ranges", DD->getNextRangeNumber()),
-      std::move(Range));
+  RangeSpanList List(Asm->createTempSymbol("debug_ranges"), std::move(Range));
 
   // Under fission, ranges are specified by constant offsets relative to the
   // CU's DW_AT_GNU_ranges_base.
@@ -709,7 +707,7 @@ void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
   // Don't bother labeling the .dwo unit, as its offset isn't used.
   if (!Skeleton) {
-    LabelBegin = Asm->createTempSymbol("cu_begin", getUniqueID());
+    LabelBegin = Asm->createTempSymbol("cu_begin");
     Asm->OutStreamer.EmitLabel(LabelBegin);
   }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 2ca29dc7919..df5dd2e8333 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -188,7 +188,7 @@ static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
     DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
 
 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
-    : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr), GlobalRangeCount(0),
+    : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr),
       InfoHolder(A, "info_string", DIEValueAllocator),
       UsedNonDefaultText(false),
       SkeletonHolder(A, "skel_string", DIEValueAllocator),
@@ -926,8 +926,7 @@ DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
     DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
     DebugLocList &LocList = DotDebugLocEntries.back();
     LocList.CU = &TheCU;
-    LocList.Label =
-        Asm->createTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
+    LocList.Label = Asm->createTempSymbol("debug_loc");
 
     // Build the location list for this variable.
     buildLocationList(LocList.List, Ranges);
@@ -1415,15 +1414,14 @@ void DwarfDebug::emitDebugPubSection(
 
     if (auto *Skeleton = TheU->getSkeleton())
       TheU = Skeleton;
-    unsigned ID = TheU->getUniqueID();
 
     // Start the dwarf pubnames section.
     Asm->OutStreamer.SwitchSection(PSec);
 
     // Emit the header.
     Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
-    MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin", ID);
-    MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end", ID);
+    MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
+    MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
     Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
 
     Asm->OutStreamer.EmitLabel(BeginLabel);
@@ -1659,7 +1657,6 @@ void DwarfDebug::emitDebugARanges() {
   }
 
   // Add terminating symbols for each section.
-  unsigned ID = 0;
   for (const auto &I : SectionMap) {
     const MCSection *Section = I.first;
     MCSymbol *Sym = nullptr;
@@ -1669,14 +1666,13 @@ void DwarfDebug::emitDebugARanges() {
       // if we know the section name up-front. For user-created sections, the
       // resulting label may not be valid to use as a label. (section names can
       // use a greater set of characters on some systems)
-      Sym = Asm->createTempSymbol("debug_end", ID);
+      Sym = Asm->createTempSymbol("debug_end");
       Asm->OutStreamer.SwitchSection(Section);
       Asm->OutStreamer.EmitLabel(Sym);
     }
 
     // Insert a final terminator.
     SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
-    ++ID;
   }
 
   DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 3a5a7f66094..74db3efcea6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -248,9 +248,6 @@ class DwarfDebug : public AsmPrinterHandler {
   // table for the same directory as DW_AT_comp_dir.
   StringRef CompilationDir;
 
-  // Counter for assigning globally unique IDs for ranges.
-  unsigned GlobalRangeCount;
-
   // Holder for the file specific debug information.
   DwarfFile InfoHolder;
 
@@ -619,12 +616,6 @@ public:
   /// \brief Return Label immediately following the instruction.
   MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
 
-  // FIXME: Consider rolling ranges up into DwarfDebug since we use a single
-  // range_base anyway, so there's no need to keep them as separate per-CU range
-  // lists. (though one day we might end up with a range.dwo section, in which
-  // case it'd go to DwarfFile)
-  unsigned getNextRangeNumber() { return GlobalRangeCount++; }
-
   // FIXME: Sink these functions down into DwarfFile/Dwarf*Unit.
 
   SmallPtrSet<const MDNode *, 16> &getProcessedSPNodes() {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
index 75249bed674..165ef16dfbc 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp
@@ -19,7 +19,7 @@ getEntry(AsmPrinter &Asm,
   std::pair<MCSymbol *, unsigned> &Entry = Pool[Str];
   if (!Entry.first) {
     Entry.second = Pool.size() - 1;
-    Entry.first = Asm.createTempSymbol(Prefix, Entry.second);
+    Entry.first = Asm.createTempSymbol(Prefix);
   }
   return Entry;
 }