Revert "[clang][AST] fix ast-print of extern <lang> with >=2 declarators" (#93912)

Reverts #93131 because it broke some lldb tests on the
Fuchsia Clang toolchain builders.

https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8746482644341901905/infra

Author: gulfemsavrun

clang/lib/AST/DeclPrinter.cpp

@@ -633,7 +633,7 @@ static void printExplicitSpecifier(ExplicitSpecifier ES, llvm::raw_ostream &Out,
   Out << Proto;
 }
 
-static void maybePrintTagKeywordIfSupressingScopes(PrintingPolicy &Policy,
+static void MaybePrintTagKeywordIfSupressingScopes(PrintingPolicy &Policy,
                                                    QualType T,
                                                    llvm::raw_ostream &Out) {
   StringRef prefix = T->isClassType()       ? "class "
@@ -643,22 +643,6 @@ static void maybePrintTagKeywordIfSupressingScopes(PrintingPolicy &Policy,
   Out << prefix;
 }
 
-/// Return the language of the linkage spec of `D`, if applicable.
-///
-/// \Return - "C" if `D` has been declared with unbraced `extern "C"`
-///         - "C++" if `D` has been declared with unbraced `extern "C++"`
-///         - nullptr in any other case
-static const char *tryGetUnbracedLinkageLanguage(const Decl *D) {
-  const auto *SD = dyn_cast<LinkageSpecDecl>(D->getDeclContext());
-  if (!SD || SD->hasBraces())
-    return nullptr;
-  if (SD->getLanguage() == LinkageSpecLanguageIDs::C)
-    return "C";
-  assert(SD->getLanguage() == LinkageSpecLanguageIDs::CXX &&
-         "unknown language in linkage specification");
-  return "C++";
-}
-
 void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
   if (!D->getDescribedFunctionTemplate() &&
       !D->isFunctionTemplateSpecialization()) {
@@ -678,11 +662,6 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
   CXXConversionDecl *ConversionDecl = dyn_cast<CXXConversionDecl>(D);
   CXXDeductionGuideDecl *GuideDecl = dyn_cast<CXXDeductionGuideDecl>(D);
   if (!Policy.SuppressSpecifiers) {
-    if (const char *Lang = tryGetUnbracedLinkageLanguage(D)) {
-      // the "extern" specifier is implicit
-      assert(D->getStorageClass() == SC_None);
-      Out << "extern \"" << Lang << "\" ";
-    }
     switch (D->getStorageClass()) {
     case SC_None: break;
     case SC_Extern: Out << "extern "; break;
@@ -828,7 +807,7 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
       }
       if (!Policy.SuppressTagKeyword && Policy.SuppressScope &&
           !Policy.SuppressUnwrittenScope)
-        maybePrintTagKeywordIfSupressingScopes(Policy, AFT->getReturnType(),
+        MaybePrintTagKeywordIfSupressingScopes(Policy, AFT->getReturnType(),
                                                Out);
       AFT->getReturnType().print(Out, Policy, Proto);
       Proto.clear();
@@ -953,11 +932,6 @@ void DeclPrinter::VisitVarDecl(VarDecl *D) {
     : D->getASTContext().getUnqualifiedObjCPointerType(D->getType());
 
   if (!Policy.SuppressSpecifiers) {
-    if (const char *Lang = tryGetUnbracedLinkageLanguage(D)) {
-      // the "extern" specifier is implicit
-      assert(D->getStorageClass() == SC_None);
-      Out << "extern \"" << Lang << "\" ";
-    }
     StorageClass SC = D->getStorageClass();
     if (SC != SC_None)
       Out << VarDecl::getStorageClassSpecifierString(SC) << " ";
@@ -987,7 +961,7 @@ void DeclPrinter::VisitVarDecl(VarDecl *D) {
 
   if (!Policy.SuppressTagKeyword && Policy.SuppressScope &&
       !Policy.SuppressUnwrittenScope)
-    maybePrintTagKeywordIfSupressingScopes(Policy, T, Out);
+    MaybePrintTagKeywordIfSupressingScopes(Policy, T, Out);
 
   printDeclType(T, (isa<ParmVarDecl>(D) && Policy.CleanUglifiedParameters &&
                     D->getIdentifier())
@@ -1090,8 +1064,6 @@ void DeclPrinter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
 
 void DeclPrinter::VisitEmptyDecl(EmptyDecl *D) {
   prettyPrintAttributes(D);
-  if (const char *Lang = tryGetUnbracedLinkageLanguage(D))
-    Out << "extern \"" << Lang << "\";";
 }
 
 void DeclPrinter::VisitCXXRecordDecl(CXXRecordDecl *D) {
@@ -1164,21 +1136,22 @@ void DeclPrinter::VisitCXXRecordDecl(CXXRecordDecl *D) {
 }
 
 void DeclPrinter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
-  if (!D->hasBraces()) {
-    VisitDeclContext(D);
-    return;
-  }
-  const char *L;
+  const char *l;
   if (D->getLanguage() == LinkageSpecLanguageIDs::C)
-    L = "C";
+    l = "C";
   else {
     assert(D->getLanguage() == LinkageSpecLanguageIDs::CXX &&
            "unknown language in linkage specification");
-    L = "C++";
+    l = "C++";
   }
-  Out << "extern \"" << L << "\" {\n";
-  VisitDeclContext(D);
-  Indent() << "}";
+
+  Out << "extern \"" << l << "\" ";
+  if (D->hasBraces()) {
+    Out << "{\n";
+    VisitDeclContext(D);
+    Indent() << "}";
+  } else
+    Visit(*D->decls_begin());
 }
 
 void DeclPrinter::printTemplateParameters(const TemplateParameterList *Params,