[Basic] Move copyCString to Basic/StringExtras.

Also, use StringRef.copy() instead of copyString().

Author: rintaro

include/swift/Basic/StringExtras.h

@@ -52,12 +52,16 @@ namespace swift {
   /// Determine the part of speech for the given word.
   PartOfSpeech getPartOfSpeech(StringRef word);
 
+  /// Copy \p string to \p Allocator and return it as a null terminated C
+  /// string.
+  const char *copyCString(StringRef string, llvm::BumpPtrAllocator &Allocator);
+
   /// Scratch space used for returning a set of StringRefs.
   class StringScratchSpace {
     llvm::BumpPtrAllocator Allocator;
 
   public:
-    StringRef copyString(StringRef string);
+    StringRef copyString(StringRef string) { return string.copy(Allocator); }
 
     llvm::BumpPtrAllocator &getAllocator() { return Allocator; }
   };

include/swift/IDE/CodeCompletion.h

@@ -64,12 +64,6 @@ std::string removeCodeCompletionTokens(StringRef Input,
                                        StringRef TokenName,
                                        unsigned *CompletionOffset);
 
-StringRef copyString(llvm::BumpPtrAllocator &Allocator,
-                     StringRef Str);
-
-const char *copyCString(llvm::BumpPtrAllocator &Allocator,
-                        StringRef Str);
-
 template <typename T>
 ArrayRef<T> copyArray(llvm::BumpPtrAllocator &Allocator,
                             ArrayRef<T> Arr) {

lib/Basic/StringExtras.cpp

@@ -457,10 +457,14 @@ StringRef swift::matchLeadingTypeName(StringRef name,
   return nameMismatch.getRestOfStr();
 }
 
-StringRef StringScratchSpace::copyString(StringRef string) {
-  void *memory = Allocator.Allocate(string.size(), alignof(char));
+const char *swift::copyCString(StringRef string,
+                               llvm::BumpPtrAllocator &Allocator) {
+  if (string.empty())
+    return "";
+  char *memory = Allocator.Allocate<char>(string.size() + 1);
   memcpy(memory, string.data(), string.size());
-  return StringRef(static_cast<char *>(memory), string.size());
+  memory[string.size()] = '\0';
+  return memory;
 }
 
 void InheritedNameSet::add(StringRef name) {

lib/IDE/CodeCompletion.cpp

@@ -111,21 +111,6 @@ std::string swift::ide::removeCodeCompletionTokens(
   return CleanFile;
 }
 
-llvm::StringRef swift::ide::copyString(llvm::BumpPtrAllocator &Allocator,
-                                       llvm::StringRef Str) {
-  char *Buffer = Allocator.Allocate<char>(Str.size());
-  std::copy(Str.begin(), Str.end(), Buffer);
-  return llvm::StringRef(Buffer, Str.size());
-}
-
-const char *swift::ide::copyCString(llvm::BumpPtrAllocator &Allocator,
-                                    llvm::StringRef Str) {
-  char *Buffer = Allocator.Allocate<char>(Str.size() + 1);
-  std::copy(Str.begin(), Str.end(), Buffer);
-  Buffer[Str.size()] = '\0';
-  return Buffer;
-}
-
 CodeCompletionString::CodeCompletionString(ArrayRef<Chunk> Chunks) {
   std::uninitialized_copy(Chunks.begin(), Chunks.end(),
                           getTrailingObjects<Chunk>());
@@ -729,7 +714,7 @@ void CodeCompletionResultBuilder::withNestedGroup(
 
 void CodeCompletionResultBuilder::addChunkWithText(
     CodeCompletionString::Chunk::ChunkKind Kind, StringRef Text) {
-  addChunkWithTextNoCopy(Kind, copyString(*Sink.Allocator, Text));
+  addChunkWithTextNoCopy(Kind, Text.copy(*Sink.Allocator));
 }
 
 void CodeCompletionResultBuilder::setAssociatedDecl(const Decl *D) {
@@ -1172,7 +1157,7 @@ void CodeCompletionResultBuilder::addTypeAnnotation(Type T, PrintOptions PO,
 }
 
 StringRef CodeCompletionContext::copyString(StringRef Str) {
-  return ::copyString(*CurrentResults.Allocator, Str);
+  return Str.copy(*CurrentResults.Allocator);
 }
 
 bool shouldCopyAssociatedUSRForDecl(const ValueDecl *VD) {
@@ -1214,7 +1199,7 @@ ArrayRef<StringRef> copyAssociatedUSRs(llvm::BumpPtrAllocator &Allocator,
     }
 
     if (!Ignored)
-      USRs.push_back(copyString(Allocator, SS));
+      USRs.push_back(SS.str().copy(Allocator));
   });
 
   if (!USRs.empty())
@@ -1314,7 +1299,7 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
       if (!getContextFreeCompletionDiagnostics(ContextFreeNotRecReason, VD,
                                                severity, messageOS)) {
         ContextFreeDiagnosticSeverity = severity;
-        ContextFreeDiagnosticMessage = copyString(*Sink.Allocator, message);
+        ContextFreeDiagnosticMessage = message.str().copy(*Sink.Allocator);
       }
     }
   }
@@ -1330,11 +1315,12 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
         ModuleName = Sink.LastModule.second;
       } else {
         if (auto *C = CurrentModule.dyn_cast<const clang::Module *>()) {
-          ModuleName = copyString(*Sink.Allocator, C->getFullModuleName());
+          ModuleName = StringRef(C->getFullModuleName()).copy(*Sink.Allocator);
         } else {
-          ModuleName = copyString(
-              *Sink.Allocator,
-              CurrentModule.get<const swift::ModuleDecl *>()->getName().str());
+          ModuleName = CurrentModule.get<const swift::ModuleDecl *>()
+                           ->getName()
+                           .str()
+                           .copy(*Sink.Allocator);
         }
         Sink.LastModule.first = CurrentModule.getOpaqueValue();
         Sink.LastModule.second = ModuleName;
@@ -1343,7 +1329,7 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
 
     ContextFreeResult = ContextFreeCodeCompletionResult::createDeclResult(
         *Sink.Allocator, CCS, AssociatedDecl, ModuleName,
-        copyString(*Sink.Allocator, BriefDocComment),
+        BriefDocComment.copy(*Sink.Allocator),
         copyAssociatedUSRs(*Sink.Allocator, AssociatedDecl), ResultType,
         ContextFreeNotRecReason, ContextFreeDiagnosticSeverity,
         ContextFreeDiagnosticMessage);
@@ -1353,14 +1339,14 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
   case CodeCompletionResultKind::Keyword:
     ContextFreeResult = ContextFreeCodeCompletionResult::createKeywordResult(
         *Sink.Allocator, KeywordKind, CCS,
-        copyString(*Sink.Allocator, BriefDocComment), ResultType);
+        BriefDocComment.copy(*Sink.Allocator), ResultType);
     break;
   case CodeCompletionResultKind::BuiltinOperator:
   case CodeCompletionResultKind::Pattern:
     ContextFreeResult =
         ContextFreeCodeCompletionResult::createPatternOrBuiltInOperatorResult(
             *Sink.Allocator, Kind, CCS, CodeCompletionOperatorKind::None,
-            copyString(*Sink.Allocator, BriefDocComment), ResultType,
+            BriefDocComment.copy(*Sink.Allocator), ResultType,
             ContextFreeNotRecReason, ContextFreeDiagnosticSeverity,
             ContextFreeDiagnosticMessage);
     break;
@@ -1383,7 +1369,7 @@ CodeCompletionResult *CodeCompletionResultBuilder::takeResult() {
       if (!getContextualCompletionDiagnostics(ContextualNotRecReason, VD,
                                               severity, messageOS)) {
         ContextualDiagnosticSeverity = severity;
-        ContextualDiagnosticMessage = copyString(*Sink.Allocator, message);
+        ContextualDiagnosticMessage = message.str().copy(*Sink.Allocator);
       }
     }
   }

lib/IDE/CodeCompletionCache.cpp

@@ -12,6 +12,7 @@
 
 #include "swift/IDE/CodeCompletionCache.h"
 #include "swift/Basic/Cache.h"
+#include "swift/Basic/StringExtras.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Hashing.h"
@@ -165,8 +166,11 @@ static bool readCachedModule(llvm::MemoryBuffer *in,
     }
 
     const char *p = strings + index;
-    auto size = read32le(p);
-    auto str = copyString(*V.Allocator, StringRef(p, size));
+    size_t size = read32le(p);
+    StringRef str = StringRef(p, size);
+    // Import the string to the allocator. Use null-terminated string to avoid
+    // potential copies in clients.
+    str = StringRef(copyCString(str, *V.Allocator), size);
     knownStrings[index] = str;
     return str;
   };

lib/IDE/CodeCompletionResultPrinter.cpp

@@ -13,6 +13,7 @@
 #include "swift/IDE/CodeCompletionResultPrinter.h"
 #include "swift/AST/ASTPrinter.h"
 #include "swift/Basic/LLVM.h"
+#include "swift/Basic/StringExtras.h"
 #include "swift/IDE/CodeCompletion.h"
 #include "swift/Markup/XMLUtils.h"
 #include "llvm/Support/raw_ostream.h"
@@ -541,9 +542,7 @@ StringRef swift::ide::getCodeCompletionResultFilterName(
   SmallString<32> buf;
   llvm::raw_svector_ostream OS(buf);
   printCodeCompletionResultFilterName(Str, OS);
-  size_t size = buf.size();
-  char *storage = Allocator.Allocate<char>(size + 1);
-  memcpy(storage, buf.data(), size);
-  storage[size] = '\0';
-  return {storage, size};
+  // Use 'copyCString' to get a null terminated StringRef just in case clients
+  // need it.
+  return {copyCString(buf, Allocator), buf.size()};
 }

tools/SourceKit/lib/SwiftLang/CodeCompletionOrganizer.cpp

@@ -126,7 +126,7 @@ bool SourceKit::CodeCompletion::addCustomCompletions(
 
   auto addCompletion = [&](CustomCompletionInfo customCompletion) {
     using Chunk = CodeCompletionString::Chunk;
-    auto nameCopy = copyString(sink.allocator, customCompletion.Name);
+    auto nameCopy = StringRef(customCompletion.Name).copy(sink.allocator);
     auto chunk = Chunk::createWithText(Chunk::ChunkKind::Text, 0, nameCopy);
     auto *completionString =
         CodeCompletionString::create(sink.allocator, chunk);
@@ -1187,7 +1187,7 @@ Completion *CompletionBuilder::finish() {
   }
 
   auto *result = new (sink.allocator)
-      Completion(*newBase, copyString(sink.allocator, description));
+      Completion(*newBase, description.str().copy(sink.allocator));
   result->moduleImportDepth = moduleImportDepth;
   result->popularityFactor = popularityFactor;
   result->opaqueCustomKind = customKind;

tools/SourceKit/lib/SwiftLang/SwiftSourceDocInfo.cpp

@@ -760,7 +760,7 @@ static StringRef getModuleName(const ValueDecl *VD,
       static_cast<ClangImporter *>(Ctx.getClangModuleLoader());
   if (auto ClangNode = VD->getClangNode()) {
     if (const auto *ClangMod = Importer->getClangOwningModule(ClangNode))
-      return copyString(Allocator, ClangMod->getFullModuleName());
+      return StringRef(ClangMod->getFullModuleName()).copy(Allocator);
     return "";
   }
 
@@ -824,7 +824,7 @@ struct DeclInfo {
 
 static StringRef copyAndClearString(llvm::BumpPtrAllocator &Allocator,
                                     SmallVectorImpl<char> &Str) {
-  auto Ref = copyString(Allocator, StringRef(Str.data(), Str.size()));
+  auto Ref = StringRef(Str.data(), Str.size()).copy(Allocator);
   Str.clear();
   return Ref;
 }
@@ -998,7 +998,7 @@ fillSymbolInfo(CursorSymbolInfo &Symbol, const DeclInfo &DInfo,
     SmallVector<ParentInfo, 4> Parents;
     for (auto &Component : PathComponents) {
       SwiftLangSupport::printUSR(Component.VD, OS);
-      Parents.emplace_back(copyString(Allocator, Component.Title),
+      Parents.emplace_back(Component.Title.str().copy(Allocator),
                            Component.Kind,
                            copyAndClearString(Allocator, Buffer));
     };
@@ -1009,7 +1009,7 @@ fillSymbolInfo(CursorSymbolInfo &Symbol, const DeclInfo &DInfo,
       SmallVector<ParentInfo, 4> FIParents;
       for (auto &Component: FI.ParentContexts) {
         SwiftLangSupport::printUSR(Component.VD, OS);
-        FIParents.emplace_back(copyString(Allocator, Component.Title),
+        FIParents.emplace_back(Component.Title.str().copy(Allocator),
                                Component.Kind,
                                copyAndClearString(Allocator, Buffer));
       }