[llvm][CodeGen] Avoid 'raw_string_ostream::str' (NFC) (#97318)

Since `raw_string_ostream` doesn't own the string buffer, it is
desirable (in terms of memory safety) for users to directly reference
the string buffer rather than use `raw_string_ostream::str()`.

Work towards TODO comment to remove `raw_string_ostream::str()`.

11 files changed, 20 insertions, 21 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 0033f0a..c52cbff 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1128,7 +1128,7 @@ static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
     OS << ' ' << (Op.isDef() ? "def " : "killed ")
        << printReg(Op.getReg(), AP.MF->getSubtarget().getRegisterInfo());
   }
-  AP.OutStreamer->AddComment(OS.str());
+  AP.OutStreamer->AddComment(Str);
   AP.OutStreamer->addBlankLine();
 }
 
@@ -1235,7 +1235,7 @@ static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
   }
 
   // NOTE: Want this comment at start of line, don't emit with AddComment.
-  AP.OutStreamer->emitRawComment(OS.str());
+  AP.OutStreamer->emitRawComment(Str);
   return true;
 }
 
@@ -2274,7 +2274,7 @@ void AsmPrinter::emitRemarksSection(remarks::RemarkStreamer &RS) {
       OutContext.getObjectFileInfo()->getRemarksSection();
   OutStreamer->switchSection(RemarksSection);
 
-  OutStreamer->emitBinaryData(OS.str());
+  OutStreamer->emitBinaryData(Buf);
 }
 
 bool AsmPrinter::doFinalization(Module &M) {
@@ -3282,7 +3282,7 @@ const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
   OS << "Unsupported expression in static initializer: ";
   CE->printAsOperand(OS, /*PrintType=*/false,
                      !MF ? nullptr : MF->getFunction().getParent());
-  report_fatal_error(Twine(OS.str()));
+  report_fatal_error(Twine(S));
 }
 
 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
index 08e3c20..5a7013c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -311,7 +311,7 @@ static void EmitInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
           std::string msg;
           raw_string_ostream Msg(msg);
           Msg << "invalid operand in inline asm: '" << AsmStr << "'";
-          MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
+          MMI->getModule()->getContext().emitError(LocCookie, msg);
         }
       }
       break;
@@ -411,7 +411,7 @@ void AsmPrinter::emitInlineAsm(const MachineInstr *MI) const {
     }
   }
 
-  emitInlineAsm(OS.str(), getSubtargetInfo(), TM.Options.MCOptions, LocMD,
+  emitInlineAsm(StringData, getSubtargetInfo(), TM.Options.MCOptions, LocMD,
                 MI->getInlineAsmDialect());
 
   // Emit the #NOAPP end marker.  This has to happen even if verbose-asm isn't
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 14e6b79..552d4c9 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -3984,7 +3984,7 @@ bool IRTranslator::runOnMachineFunction(MachineFunction &CurMF) {
           raw_string_ostream InstStr(InstStrStorage);
           InstStr << Inst;
 
-          R << ": '" << InstStr.str() << "'";
+          R << ": '" << InstStrStorage << "'";
         }
 
         reportTranslationError(*MF, *TPC, *ORE, R);
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index 49993f7..48c3e0d 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -570,7 +570,7 @@ void MIRPrinter::convertMachineMetadataNodes(yaml::MachineFunction &YMF,
     std::string NS;
     raw_string_ostream StrOS(NS);
     MD.second->print(StrOS, MST, MF.getFunction().getParent());
-    YMF.MachineMetadataNodes.push_back(StrOS.str());
+    YMF.MachineMetadataNodes.push_back(NS);
   }
 }
 
@@ -588,7 +588,7 @@ void MIRPrinter::convert(yaml::MachineFunction &MF,
 
     yaml::MachineConstantPoolValue YamlConstant;
     YamlConstant.ID = ID++;
-    YamlConstant.Value = StrOS.str();
+    YamlConstant.Value = Str;
     YamlConstant.Alignment = Constant.getAlign();
     YamlConstant.IsTargetSpecific = Constant.isMachineConstantPoolEntry();
 
@@ -608,7 +608,7 @@ void MIRPrinter::convert(ModuleSlotTracker &MST,
     for (const auto *MBB : Table.MBBs) {
       raw_string_ostream StrOS(Str);
       StrOS << printMBBReference(*MBB);
-      Entry.Blocks.push_back(StrOS.str());
+      Entry.Blocks.push_back(Str);
       Str.clear();
     }
     YamlJTI.Entries.push_back(Entry);
diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index 76e5952..c7ccf10 100644
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -804,8 +804,7 @@ MachineFunction *MachineOutliner::createOutlinedFunction(
     Mg.getNameWithPrefix(MangledNameStream, F, false);
 
     DISubprogram *OutlinedSP = DB.createFunction(
-        Unit /* Context */, F->getName(), StringRef(MangledNameStream.str()),
-        Unit /* File */,
+        Unit /* Context */, F->getName(), StringRef(Dummy), Unit /* File */,
         0 /* Line 0 is reserved for compiler-generated code. */,
         DB.createSubroutineType(
             DB.getOrCreateTypeArray(std::nullopt)), /* void type */
diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index cf72f74..4a6d5ed 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -4413,7 +4413,7 @@ struct DOTGraphTraits<ScheduleDAGMI*> : public DefaultDOTGraphTraits {
     SS << "SU:" << SU->NodeNum;
     if (DFS)
       SS << " I:" << DFS->getNumInstrs(SU);
-    return SS.str();
+    return Str;
   }
 
   static std::string getNodeDescription(const SUnit *SU, const ScheduleDAG *G) {
diff --git a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
index c848ce4..68dece6 100644
--- a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -1206,7 +1206,7 @@ std::string ScheduleDAGInstrs::getGraphNodeLabel(const SUnit *SU) const {
     oss << "<exit>";
   else
     SU->getInstr()->print(oss, /*IsStandalone=*/true);
-  return oss.str();
+  return s;
 }
 
 /// Return the basic block label. It is not necessarilly unique because a block
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 7429763..bc16f88 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -11749,7 +11749,7 @@ SDValue SelectionDAG::getSymbolFunctionGlobalAddress(SDValue Op,
   raw_string_ostream ErrorFormatter(ErrorStr);
   ErrorFormatter << "Undefined external symbol ";
   ErrorFormatter << '"' << Symbol << '"';
-  report_fatal_error(Twine(ErrorFormatter.str()));
+  report_fatal_error(Twine(ErrorStr));
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 8ce6dfc..ecdbf3e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1778,7 +1778,7 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
             raw_string_ostream InstStr(InstStrStorage);
             InstStr << *Inst;
 
-            R << ": " << InstStr.str();
+            R << ": " << InstStrStorage;
           }
 
           reportFastISelFailure(*MF, *ORE, R, EnableFastISelAbort > 2);
@@ -1827,7 +1827,7 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
           std::string InstStrStorage;
           raw_string_ostream InstStr(InstStrStorage);
           InstStr << *Inst;
-          R << ": " << InstStr.str();
+          R << ": " << InstStrStorage;
         }
 
         reportFastISelFailure(*MF, *ORE, R, ShouldAbort);
@@ -4370,5 +4370,5 @@ void SelectionDAGISel::CannotYetSelect(SDNode *N) {
     else
       Msg << "unknown intrinsic #" << iid;
   }
-  report_fatal_error(Twine(Msg.str()));
+  report_fatal_error(Twine(msg));
 }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
index b66eeb6..ac28f62 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp
@@ -299,7 +299,7 @@ std::string ScheduleDAGSDNodes::getGraphNodeLabel(const SUnit *SU) const {
   } else {
     O << "CROSS RC COPY";
   }
-  return O.str();
+  return s;
 }
 
 void ScheduleDAGSDNodes::getCustomGraphFeatures(GraphWriter<ScheduleDAG*> &GW) const {
diff --git a/llvm/lib/CodeGen/TargetInstrInfo.cpp b/llvm/lib/CodeGen/TargetInstrInfo.cpp
index e01e7b3..3cd1bb2 100644
--- a/llvm/lib/CodeGen/TargetInstrInfo.cpp
+++ b/llvm/lib/CodeGen/TargetInstrInfo.cpp
@@ -1750,7 +1750,7 @@ std::string TargetInstrInfo::createMIROperandComment(
       OS << Info;
     }
 
-    return OS.str();
+    return Flags;
   }
 
   int FlagIdx = MI.findInlineAsmFlagIdx(OpIdx);
@@ -1784,7 +1784,7 @@ std::string TargetInstrInfo::createMIROperandComment(
       F.getRegMayBeFolded())
     OS << " foldable";
 
-  return OS.str();
+  return Flags;
 }
 
 TargetInstrInfo::PipelinerLoopInfo::~PipelinerLoopInfo() = default;