From c758181525cbd4a603d6fd518ed33d9f324a7009 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Sun, 26 Apr 2020 17:23:30 +0200
Subject: [PATCH] [clang-tidy] Use StringSwitch in a bunch of places. NFCI.

---
 .../abseil/DurationFactoryScaleCheck.cpp           | 21 ++++++++-----------
 .../modernize/DeprecatedIosBaseAliasesCheck.cpp    | 19 +++++++++--------
 .../clang-tidy/portability/SIMDIntrinsicsCheck.cpp | 24 ++++++++--------------
 3 files changed, 28 insertions(+), 36 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/abseil/DurationFactoryScaleCheck.cpp b/clang-tools-extra/clang-tidy/abseil/DurationFactoryScaleCheck.cpp
index b582885..0e537fc 100644
--- a/clang-tools-extra/clang-tidy/abseil/DurationFactoryScaleCheck.cpp
+++ b/clang-tools-extra/clang-tidy/abseil/DurationFactoryScaleCheck.cpp
@@ -23,19 +23,14 @@ namespace abseil {
 // `FactoryName`, return `None`.
 static llvm::Optional<DurationScale>
 getScaleForFactory(llvm::StringRef FactoryName) {
-  static const std::unordered_map<std::string, DurationScale> ScaleMap(
-      {{"Nanoseconds", DurationScale::Nanoseconds},
-       {"Microseconds", DurationScale::Microseconds},
-       {"Milliseconds", DurationScale::Milliseconds},
-       {"Seconds", DurationScale::Seconds},
-       {"Minutes", DurationScale::Minutes},
-       {"Hours", DurationScale::Hours}});
-
-  auto ScaleIter = ScaleMap.find(std::string(FactoryName));
-  if (ScaleIter == ScaleMap.end())
-    return llvm::None;
-
-  return ScaleIter->second;
+  return llvm::StringSwitch<llvm::Optional<DurationScale>>(FactoryName)
+      .Case("Nanoseconds", DurationScale::Nanoseconds)
+      .Case("Microseconds", DurationScale::Microseconds)
+      .Case("Milliseconds", DurationScale::Milliseconds)
+      .Case("Seconds", DurationScale::Seconds)
+      .Case("Minutes", DurationScale::Minutes)
+      .Case("Hours", DurationScale::Hours)
+      .Default(llvm::None);
 }
 
 // Given either an integer or float literal, return its value.
diff --git a/clang-tools-extra/clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp b/clang-tools-extra/clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp
index 15eb2e8..2eef983 100644
--- a/clang-tools-extra/clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/DeprecatedIosBaseAliasesCheck.cpp
@@ -21,10 +21,13 @@ static constexpr std::array<StringRef, 5> DeprecatedTypes = {
     "::std::ios_base::seek_dir", "::std::ios_base::streamoff",
     "::std::ios_base::streampos"};
 
-static const llvm::StringMap<StringRef> ReplacementTypes = {
-    {"io_state", "iostate"},
-    {"open_mode", "openmode"},
-    {"seek_dir", "seekdir"}};
+static llvm::Optional<const char *> getReplacementType(StringRef Type) {
+  return llvm::StringSwitch<llvm::Optional<const char *>>(Type)
+      .Case("io_state", "iostate")
+      .Case("open_mode", "openmode")
+      .Case("seek_dir", "seekdir")
+      .Default(llvm::None);
+}
 
 void DeprecatedIosBaseAliasesCheck::registerMatchers(MatchFinder *Finder) {
   auto IoStateDecl = typedefDecl(hasAnyName(DeprecatedTypes)).bind("TypeDecl");
@@ -40,14 +43,14 @@ void DeprecatedIosBaseAliasesCheck::check(
 
   const auto *Typedef = Result.Nodes.getNodeAs<TypedefDecl>("TypeDecl");
   StringRef TypeName = Typedef->getName();
-  bool HasReplacement = ReplacementTypes.count(TypeName);
+  auto Replacement = getReplacementType(TypeName);
 
   const auto *TL = Result.Nodes.getNodeAs<TypeLoc>("TypeLoc");
   SourceLocation IoStateLoc = TL->getBeginLoc();
 
   // Do not generate fixits for matches depending on template arguments and
   // macro expansions.
-  bool Fix = HasReplacement && !TL->getType()->isDependentType();
+  bool Fix = Replacement && !TL->getType()->isDependentType();
   if (IoStateLoc.isMacroID()) {
     IoStateLoc = SM.getSpellingLoc(IoStateLoc);
     Fix = false;
@@ -55,8 +58,8 @@ void DeprecatedIosBaseAliasesCheck::check(
 
   SourceLocation EndLoc = IoStateLoc.getLocWithOffset(TypeName.size() - 1);
 
-  if (HasReplacement) {
-    auto FixName = ReplacementTypes.lookup(TypeName);
+  if (Replacement) {
+    auto FixName = *Replacement;
     auto Builder = diag(IoStateLoc, "'std::ios_base::%0' is deprecated; use "
                                     "'std::ios_base::%1' instead")
                    << TypeName << FixName;
diff --git a/clang-tools-extra/clang-tidy/portability/SIMDIntrinsicsCheck.cpp b/clang-tools-extra/clang-tidy/portability/SIMDIntrinsicsCheck.cpp
index d567f52..db9cc8c 100644
--- a/clang-tools-extra/clang-tidy/portability/SIMDIntrinsicsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/portability/SIMDIntrinsicsCheck.cpp
@@ -43,21 +43,15 @@ static StringRef TrySuggestPPC(StringRef Name) {
   if (!Name.consume_front("vec_"))
     return {};
 
-  static const llvm::StringMap<StringRef> Mapping{
-    // [simd.alg]
-    {"max", "$std::max"},
-    {"min", "$std::min"},
-
-    // [simd.binary]
-    {"add", "operator+ on $simd objects"},
-    {"sub", "operator- on $simd objects"},
-    {"mul", "operator* on $simd objects"},
-  };
-
-  auto It = Mapping.find(Name);
-  if (It != Mapping.end())
-    return It->second;
-  return {};
+  return llvm::StringSwitch<StringRef>(Name)
+      // [simd.alg]
+      .Case("max", "$std::max")
+      .Case("min", "$std::min")
+      // [simd.binary]
+      .Case("add", "operator+ on $simd objects")
+      .Case("sub", "operator- on $simd objects")
+      .Case("mul", "operator* on $simd objects")
+      .Default({});
 }
 
 static StringRef TrySuggestX86(StringRef Name) {
-- 
2.7.4