[StringExtras] Rename SubsequentDelim to ListSeparator

[kazu]

Summary

This patch renames SubsequentDelim to ListSeparator to clarify the
purpose of the class.

[dblaikie]

Sounds good to me - but give it a day or two. @MaskRay or others might want to weigh in.

[MaskRay]

Thanks. The new name looks better! I mentioned the patch on discord. Hope one day or two is sufficient for interested folks to weigh in.

llvm/unittests/ADT/StringExtrasTest.cpp

224

Not sure whether it should be committed separately:
using LS the third time is useful but untested.

llvm/include/llvm/ADT/StringExtras.h

inline std::string join_items(Sep Separator, Args &&... Items) {
   return Result;
 }
 
 /// A helper class to return the specified delimiter string after the first
 /// invocation of operator StringRef().  Used to generate a comma-separated
 /// list from a loop like so:
 ///
 /// \code
-///   SubsequentDelim SD;
+///   ListSeparator SD;
 ///   for (auto &I : C)
 ///     OS << SD << I.getName();
 /// \end
-class SubsequentDelim {
+class ListSeparator {
   bool First = true;
-  StringRef Delim;
+  StringRef Separator;
 
- public:
-  SubsequentDelim(StringRef Delim = ", ") : Delim(Delim) {}
+  ListSeparator(StringRef Separator = ", ") : Separator(Separator) {}
   operator StringRef() {
     if (First) {
       First = false;
       return {};
     }
-    return Delim;
+    return Separator;
   }
 };
 
 } // end namespace llvm
 
 #endif // LLVM_ADT_STRINGEXTRAS_H

llvm/lib/CodeGen/MachineBasicBlock.cpp

void MachineBasicBlock::print(raw_ostream &OS, ModuleSlotTracker &MST,
   const TargetInstrInfo &TII = *getParent()->getSubtarget().getInstrInfo();
   bool HasLineAttributes = false;
 
   // Print the preds of this block according to the CFG.
   if (!pred_empty() && IsStandalone) {
     if (Indexes) OS << '\t';
     // Don't indent(2), align with previous line attributes.
     OS << "; predecessors: ";
-    SubsequentDelim SD;
+    ListSeparator LS;
     for (auto *Pred : predecessors())
-      OS << SD << printMBBReference(*Pred);
+      OS << LS << printMBBReference(*Pred);
     OS << '\n';
     HasLineAttributes = true;
   }
 
   if (!succ_empty()) {
     if (Indexes) OS << '\t';
     // Print the successors
     OS.indent(2) << "successors: ";
-    SubsequentDelim SD;
+    ListSeparator LS;
     for (auto I = succ_begin(), E = succ_end(); I != E; ++I) {
-      OS << SD << printMBBReference(**I);
+      OS << LS << printMBBReference(**I);
       if (!Probs.empty())
         OS << '('
            << format("0x%08" PRIx32, getSuccProbability(I).getNumerator())
            << ')';
     }
     if (!Probs.empty() && IsStandalone) {
       // Print human readable probabilities as comments.
       OS << "; ";
-      SubsequentDelim SD;
+      ListSeparator LS;
       for (auto I = succ_begin(), E = succ_end(); I != E; ++I) {
         const BranchProbability &BP = getSuccProbability(I);
-        OS << SD << printMBBReference(**I) << '('
+        OS << LS << printMBBReference(**I) << '('
            << format("%.2f%%",
                      rint(((double)BP.getNumerator() / BP.getDenominator()) *
                           100.0 * 100.0) /
                          100.0)
            << ')';
       }
     }
 
     OS << '\n';
     HasLineAttributes = true;
   }
 
   if (!livein_empty() && MRI.tracksLiveness()) {
     if (Indexes) OS << '\t';
     OS.indent(2) << "liveins: ";
 
-    SubsequentDelim SD;
+    ListSeparator LS;
     for (const auto &LI : liveins()) {
-      OS << SD << printReg(LI.PhysReg, TRI);
+      OS << LS << printReg(LI.PhysReg, TRI);
       if (!LI.LaneMask.all())
         OS << ":0x" << PrintLaneMask(LI.LaneMask);
     }
     HasLineAttributes = true;
   }
 
   if (HasLineAttributes)
     OS << '\n';

llvm/unittests/ADT/StringExtrasTest.cpp

 TEST(StringExtras, IToStr) {
   EXPECT_EQ("0", itostr(0));
   EXPECT_EQ("1", itostr(1));
   EXPECT_EQ("-1", itostr(-1));
   EXPECT_EQ(std::to_string(MinInt64), itostr(MinInt64));
   EXPECT_EQ(std::to_string(MaxInt64), itostr(MaxInt64));
 }
 
-TEST(StringExtras, SubsequentDelim) {
-  SubsequentDelim SD;
-  StringRef S = SD;
+TEST(StringExtras, ListSeparator) {
+  ListSeparator LS;
+  StringRef S = LS;
   EXPECT_EQ(S, "");
-  S = SD;
+  S = LS;
   EXPECT_EQ(S, ", ");
 
-  SubsequentDelim SD2(" ");
-  S = SD2;
+  ListSeparator LS2(" ");
+  S = LS2;
   EXPECT_EQ(S, "");
-  S = SD2;
+  S = LS2;
   EXPECT_EQ(S, " ");
 }