[NFC] Restructure linkage name printing in AsmWriter

This restructuring was suggested in the review for D46699, which
prepares the linkage type printer for use in printing the ThinLTO
summary index (where we want to print "external" and also don't
want a space after the linkage type as it is printed by the caller).

llvm-svn: 333281

llvm/lib/IR/AsmWriter.cpp

@@ -2478,6 +2478,43 @@ void AssemblyWriter::printModule(const Module *M) {
   }
 }
 
+static std::string getLinkageName(GlobalValue::LinkageTypes LT) {
+  switch (LT) {
+  case GlobalValue::ExternalLinkage:
+    return "external";
+  case GlobalValue::PrivateLinkage:
+    return "private";
+  case GlobalValue::InternalLinkage:
+    return "internal";
+  case GlobalValue::LinkOnceAnyLinkage:
+    return "linkonce";
+  case GlobalValue::LinkOnceODRLinkage:
+    return "linkonce_odr";
+  case GlobalValue::WeakAnyLinkage:
+    return "weak";
+  case GlobalValue::WeakODRLinkage:
+    return "weak_odr";
+  case GlobalValue::CommonLinkage:
+    return "common";
+  case GlobalValue::AppendingLinkage:
+    return "appending";
+  case GlobalValue::ExternalWeakLinkage:
+    return "extern_weak";
+  case GlobalValue::AvailableExternallyLinkage:
+    return "available_externally";
+  }
+  llvm_unreachable("invalid linkage");
+}
+
+// When printing the linkage types in IR where the ExternalLinkage is
+// not printed, and other linkage types are expected to be printed with
+// a space after the name.
+static std::string getLinkageNameWithSpace(GlobalValue::LinkageTypes LT) {
+  if (LT == GlobalValue::ExternalLinkage)
+    return "";
+  return getLinkageName(LT) + " ";
+}
+
 static void printMetadataIdentifier(StringRef Name,
                                     formatted_raw_ostream &Out) {
   if (Name.empty()) {
@@ -2524,34 +2561,6 @@ void AssemblyWriter::printNamedMDNode(const NamedMDNode *NMD) {
   Out << "}\n";
 }
 
-static const char *getLinkagePrintName(GlobalValue::LinkageTypes LT) {
-  switch (LT) {
-  case GlobalValue::ExternalLinkage:
-    return "";
-  case GlobalValue::PrivateLinkage:
-    return "private ";
-  case GlobalValue::InternalLinkage:
-    return "internal ";
-  case GlobalValue::LinkOnceAnyLinkage:
-    return "linkonce ";
-  case GlobalValue::LinkOnceODRLinkage:
-    return "linkonce_odr ";
-  case GlobalValue::WeakAnyLinkage:
-    return "weak ";
-  case GlobalValue::WeakODRLinkage:
-    return "weak_odr ";
-  case GlobalValue::CommonLinkage:
-    return "common ";
-  case GlobalValue::AppendingLinkage:
-    return "appending ";
-  case GlobalValue::ExternalWeakLinkage:
-    return "extern_weak ";
-  case GlobalValue::AvailableExternallyLinkage:
-    return "available_externally ";
-  }
-  llvm_unreachable("invalid linkage");
-}
-
 static void PrintVisibility(GlobalValue::VisibilityTypes Vis,
                             formatted_raw_ostream &Out) {
   switch (Vis) {
@@ -2640,7 +2649,7 @@ void AssemblyWriter::printGlobal(const GlobalVariable *GV) {
   if (!GV->hasInitializer() && GV->hasExternalLinkage())
     Out << "external ";
 
-  Out << getLinkagePrintName(GV->getLinkage());
+  Out << getLinkageNameWithSpace(GV->getLinkage());
   PrintDSOLocation(*GV, Out);
   PrintVisibility(GV->getVisibility(), Out);
   PrintDLLStorageClass(GV->getDLLStorageClass(), Out);
@@ -2687,7 +2696,7 @@ void AssemblyWriter::printIndirectSymbol(const GlobalIndirectSymbol *GIS) {
   WriteAsOperandInternal(Out, GIS, &TypePrinter, &Machine, GIS->getParent());
   Out << " = ";
 
-  Out << getLinkagePrintName(GIS->getLinkage());
+  Out << getLinkageNameWithSpace(GIS->getLinkage());
   PrintDSOLocation(*GIS, Out);
   PrintVisibility(GIS->getVisibility(), Out);
   PrintDLLStorageClass(GIS->getDLLStorageClass(), Out);
@@ -2790,7 +2799,7 @@ void AssemblyWriter::printFunction(const Function *F) {
   } else
     Out << "define ";
 
-  Out << getLinkagePrintName(F->getLinkage());
+  Out << getLinkageNameWithSpace(F->getLinkage());
   PrintDSOLocation(*F, Out);
   PrintVisibility(F->getVisibility(), Out);
   PrintDLLStorageClass(F->getDLLStorageClass(), Out);