[clang-tidy][NFC] Prefer `constexpr llvm::StringLiteral` over `const char *` (#147301)

Some of these are even global mutable state — probably not what was
intended!
```cpp
static const char *AnalyzerCheckNamePrefix = "clang-analyzer-";
```

5 files changed, 12 insertions, 10 deletions

diff --git a/clang-tools-extra/clang-tidy/ClangTidy.cpp b/clang-tools-extra/clang-tidy/ClangTidy.cpp
index f4ab93b..808515c 100644
--- a/clang-tools-extra/clang-tidy/ClangTidy.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidy.cpp
@@ -55,7 +55,8 @@ namespace clang::tidy {
 
 namespace {
 #if CLANG_TIDY_ENABLE_STATIC_ANALYZER
-static const char *AnalyzerCheckNamePrefix = "clang-analyzer-";
+static constexpr llvm::StringLiteral AnalyzerCheckNamePrefix =
+    "clang-analyzer-";
 
 class AnalyzerDiagnosticConsumer : public ento::PathDiagnosticConsumer {
 public:
@@ -351,10 +352,9 @@ ClangTidyASTConsumerFactory::ClangTidyASTConsumerFactory(
 static void
 setStaticAnalyzerCheckerOpts(const ClangTidyOptions &Opts,
                              clang::AnalyzerOptions &AnalyzerOptions) {
-  StringRef AnalyzerPrefix(AnalyzerCheckNamePrefix);
   for (const auto &Opt : Opts.CheckOptions) {
     StringRef OptName(Opt.getKey());
-    if (!OptName.consume_front(AnalyzerPrefix))
+    if (!OptName.consume_front(AnalyzerCheckNamePrefix))
       continue;
     // Analyzer options are always local options so we can ignore priority.
     AnalyzerOptions.Config[OptName] = Opt.getValue().Value;
@@ -476,7 +476,8 @@ std::vector<std::string> ClangTidyASTConsumerFactory::getCheckNames() {
 #if CLANG_TIDY_ENABLE_STATIC_ANALYZER
   for (const auto &AnalyzerCheck : getAnalyzerCheckersAndPackages(
            Context, Context.canEnableAnalyzerAlphaCheckers()))
-    CheckNames.push_back(AnalyzerCheckNamePrefix + AnalyzerCheck.first);
+    CheckNames.emplace_back(
+        (AnalyzerCheckNamePrefix + AnalyzerCheck.first).str());
 #endif // CLANG_TIDY_ENABLE_STATIC_ANALYZER
 
   llvm::sort(CheckNames);
diff --git a/clang-tools-extra/clang-tidy/abseil/AbseilMatcher.h b/clang-tools-extra/clang-tidy/abseil/AbseilMatcher.h
index 1eef86d..2ae3c00 100644
--- a/clang-tools-extra/clang-tidy/abseil/AbseilMatcher.h
+++ b/clang-tools-extra/clang-tidy/abseil/AbseilMatcher.h
@@ -46,12 +46,12 @@ AST_POLYMORPHIC_MATCHER(
   if (PrefixPosition == StringRef::npos)
     return false;
   Path = Path.drop_front(PrefixPosition + AbslPrefix.size());
-  static const char *AbseilLibraries[] = {
+  static constexpr llvm::StringLiteral AbseilLibraries[] = {
       "algorithm", "base",     "container", "debugging", "flags",
       "hash",      "iterator", "memory",    "meta",      "numeric",
       "profiling", "random",   "status",    "strings",   "synchronization",
       "time",      "types",    "utility"};
-  return llvm::any_of(AbseilLibraries, [&](const char *Library) {
+  return llvm::any_of(AbseilLibraries, [&](llvm::StringLiteral Library) {
     return Path.starts_with(Library);
   });
 }
diff --git a/clang-tools-extra/clang-tidy/bugprone/ComparePointerToMemberVirtualFunctionCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ComparePointerToMemberVirtualFunctionCheck.cpp
index f2746ba..1cbf1e2 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ComparePointerToMemberVirtualFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/ComparePointerToMemberVirtualFunctionCheck.cpp
@@ -25,7 +25,7 @@ namespace {
 
 AST_MATCHER(CXXMethodDecl, isVirtual) { return Node.isVirtual(); }
 
-static const char *const ErrorMsg =
+static constexpr llvm::StringLiteral ErrorMsg =
     "comparing a pointer to member virtual function with other pointer is "
     "unspecified behavior, only compare it with a null-pointer constant for "
     "equality.";
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp
index aaaaf6b..b413b12 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProTypeMemberInitCheck.cpp
@@ -373,8 +373,8 @@ static bool isEmpty(ASTContext &Context, const QualType &Type) {
   return isIncompleteOrZeroLengthArrayType(Context, Type);
 }
 
-static const char *getInitializer(QualType QT, bool UseAssignment) {
-  const char *DefaultInitializer = "{}";
+static llvm::StringLiteral getInitializer(QualType QT, bool UseAssignment) {
+  static constexpr llvm::StringLiteral DefaultInitializer = "{}";
   if (!UseAssignment)
     return DefaultInitializer;
 
diff --git a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
index 30fcba3..936a906 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
@@ -119,7 +119,8 @@ void UseUsingCheck::check(const MatchFinder::MatchResult &Result) {
   if (StartLoc.isMacroID() && IgnoreMacros)
     return;
 
-  static const char *UseUsingWarning = "use 'using' instead of 'typedef'";
+  static constexpr llvm::StringLiteral UseUsingWarning =
+      "use 'using' instead of 'typedef'";
 
   // Warn at StartLoc but do not fix if there is macro or array.
   if (MatchedDecl->getUnderlyingType()->isArrayType() || StartLoc.isMacroID()) {