Fix usage in TableGen of getValueAsString

Record::getValueAsString returns a stringref to an interned
string (apparently had been changed since most of tablegen was
written). In this patch, I audited the usage of getValueAsString
to find places where we can trivially stop storing 'std::string' and instead
keep the stringref.

There was one instance where an unnecessary 'stringstream' was being used,
so that has been removed as well to unblock the stringref replacing string fix.

Differential Revision: https://reviews.llvm.org/D38979

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@315956 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/utils/TableGen/ClangAttrEmitter.cpp b/utils/TableGen/ClangAttrEmitter.cpp
index fe615468b16aed2a5670f448c8cc10b0c5642a76..c3d593b09241702cc4ad7dc4b1948050da73a502 100644 (file)
--- a/utils/TableGen/ClangAttrEmitter.cpp
+++ b/utils/TableGen/ClangAttrEmitter.cpp
@@ -1440,7 +1440,7 @@ static void writeAttrAccessorDefinition(const Record &R, raw_ostream &OS) {
   assert(!SpellingList.empty() &&
          "Attribute with empty spelling list can't have accessors!");
   for (const auto *Accessor : Accessors) {
-    std::string Name = Accessor->getValueAsString("Name");
+    const StringRef Name = Accessor->getValueAsString("Name");
     std::vector<FlattenedSpelling> Spellings = GetFlattenedSpellings(*Accessor);
 
     OS << "  bool " << Name << "() const { return SpellingListIndex == ";
@@ -1589,7 +1589,7 @@ struct AttributeSubjectMatchRule {
   // Abstract rules are used only for sub-rules
   bool isAbstractRule() const { return getSubjects().empty(); }
 
-  std::string getName() const {
+  StringRef getName() const {
     return (Constraint ? Constraint : MetaSubject)->getValueAsString("Name");
   }
 
@@ -1821,13 +1821,11 @@ PragmaClangAttributeSupport::generateStrictConformsTo(const Record &Attr,
   // Generate a function that constructs a set of matching rules that describe
   // to which declarations the attribute should apply to.
   std::string FnName = "matchRulesFor" + Attr.getName().str();
-  std::stringstream SS;
-  SS << "static void " << FnName << "(llvm::SmallVectorImpl<std::pair<"
+  OS << "static void " << FnName << "(llvm::SmallVectorImpl<std::pair<"
      << AttributeSubjectMatchRule::EnumName
      << ", bool>> &MatchRules, const LangOptions &LangOpts) {\n";
   if (Attr.isValueUnset("Subjects")) {
-    SS << "}\n\n";
-    OS << SS.str();
+    OS << "}\n\n";
     return FnName;
   }
   const Record *SubjectObj = Attr.getValueAsDef("Subjects");
@@ -1840,24 +1838,23 @@ PragmaClangAttributeSupport::generateStrictConformsTo(const Record &Attr,
       // The rule might be language specific, so only subtract it from the given
       // rules if the specific language options are specified.
       std::vector<Record *> LangOpts = Rule.getLangOpts();
-      SS << "  MatchRules.push_back(std::make_pair(" << Rule.getEnumValue()
+      OS << "  MatchRules.push_back(std::make_pair(" << Rule.getEnumValue()
          << ", /*IsSupported=*/";
       if (!LangOpts.empty()) {
         for (auto I = LangOpts.begin(), E = LangOpts.end(); I != E; ++I) {
-          std::string Part = (*I)->getValueAsString("Name");
+          const StringRef Part = (*I)->getValueAsString("Name");
           if ((*I)->getValueAsBit("Negated"))
-            SS << "!";
-          SS << "LangOpts." + Part;
+            OS << "!";
+          OS << "LangOpts." << Part;
           if (I + 1 != E)
-            SS << " || ";
+            OS << " || ";
         }
       } else
-        SS << "true";
-      SS << "));\n";
+        OS << "true";
+      OS << "));\n";
     }
   }
-  SS << "}\n\n";
-  OS << SS.str();
+  OS << "}\n\n";
   return FnName;
 }
 
@@ -1913,7 +1910,8 @@ void PragmaClangAttributeSupport::generateParsingHelpers(raw_ostream &OS) {
       continue;
     std::string SubRuleFunction;
     if (SubMatchRules.count(Rule.MetaSubject))
-      SubRuleFunction = "isAttributeSubjectMatchSubRuleFor_" + Rule.getName();
+      SubRuleFunction =
+          ("isAttributeSubjectMatchSubRuleFor_" + Rule.getName()).str();
     else
       SubRuleFunction = "defaultIsAttributeSubjectMatchSubRuleFor";
     OS << "  Case(\"" << Rule.getName() << "\", std::make_pair("
@@ -3030,7 +3028,7 @@ static void GenerateDefaultAppertainsTo(raw_ostream &OS) {
 static std::string CalculateDiagnostic(const Record &S) {
   // If the SubjectList object has a custom diagnostic associated with it,
   // return that directly.
-  std::string CustomDiag = S.getValueAsString("CustomDiag");
+  const StringRef CustomDiag = S.getValueAsString("CustomDiag");
   if (!CustomDiag.empty())
     return CustomDiag;
 
@@ -3314,12 +3312,13 @@ static std::string GenerateLangOptRequirements(const Record &R,
   // codegen efficiency).
   std::string FnName = "check", Test;
   for (auto I = LangOpts.begin(), E = LangOpts.end(); I != E; ++I) {
-    std::string Part = (*I)->getValueAsString("Name");
+    const StringRef Part = (*I)->getValueAsString("Name");
     if ((*I)->getValueAsBit("Negated")) {
       FnName += "Not";
       Test += "!";
     }
-    Test += "S.LangOpts." + Part;
+    Test += "S.LangOpts.";
+    Test +=  Part;
     if (I + 1 != E)
       Test += " || ";
     FnName += Part;
@@ -3375,7 +3374,7 @@ static std::string GenerateTargetRequirements(const Record &Attr,
   // applies to multiple target architectures. In order for the attribute to be
   // considered valid, all of its architectures need to be included.
   if (!Attr.isValueUnset("ParseKind")) {
-    std::string APK = Attr.getValueAsString("ParseKind");
+    const StringRef APK = Attr.getValueAsString("ParseKind");
     for (const auto &I : Dupes) {
       if (I.first == APK) {
         std::vector<StringRef> DA =
@@ -3676,13 +3675,13 @@ public:
 
 static void WriteCategoryHeader(const Record *DocCategory,
                                 raw_ostream &OS) {
-  const std::string &Name = DocCategory->getValueAsString("Name");
-  OS << Name << "\n" << std::string(Name.length(), '=') << "\n";
+  const StringRef Name = DocCategory->getValueAsString("Name");
+  OS << Name << "\n" << std::string(Name.size(), '=') << "\n";
 
   // If there is content, print that as well.
-  std::string ContentStr = DocCategory->getValueAsString("Content");
+  const StringRef ContentStr = DocCategory->getValueAsString("Content");
   // Trim leading and trailing newlines and spaces.
-  OS << StringRef(ContentStr).trim();
+  OS << ContentStr.trim();
 
   OS << "\n\n";
 }
@@ -3810,16 +3809,16 @@ static void WriteDocumentation(RecordKeeper &Records,
     OS << "This attribute has been deprecated, and may be removed in a future "
        << "version of Clang.";
     const Record &Deprecated = *Doc.Documentation->getValueAsDef("Deprecated");
-    std::string Replacement = Deprecated.getValueAsString("Replacement");
+    const StringRef Replacement = Deprecated.getValueAsString("Replacement");
     if (!Replacement.empty())
       OS << "  This attribute has been superseded by ``"
          << Replacement << "``.";
     OS << "\n\n";
   }
 
-  std::string ContentStr = Doc.Documentation->getValueAsString("Content");
+  const StringRef ContentStr = Doc.Documentation->getValueAsString("Content");
   // Trim leading and trailing newlines and spaces.
-  OS << StringRef(ContentStr).trim();
+  OS << ContentStr.trim();
 
   OS << "\n\n\n";
 }
@@ -3848,7 +3847,7 @@ void EmitClangAttrDocs(RecordKeeper &Records, raw_ostream &OS) {
       // If the category is "undocumented", then there cannot be any other
       // documentation categories (otherwise, the attribute would become
       // documented).
-      std::string Cat = Category->getValueAsString("Name");
+      const StringRef Cat = Category->getValueAsString("Name");
       bool Undocumented = Cat == "Undocumented";
       if (Undocumented && Docs.size() > 1)
         PrintFatalError(Doc.getLoc(),