[ASTMatchers] Make isExpandedFromMacro accept llvm::StringRef (#167060)

We can use non-owning `StringRef` in `MacroName` parameter to avoid
unnecessary copy because `MacroName` only used as an argument to
`internal::getExpansionLocOfMacro` which already accept `StringRef`.

Author: vbvictor

clang-tools-extra/clang-tidy/objc/AssertEqualsCheck.cpp

@@ -25,7 +25,7 @@ void AssertEqualsCheck::registerMatchers(MatchFinder *Finder) {
   for (const auto &[CurrName, _] : NameMap) {
     Finder->addMatcher(
         binaryOperator(anyOf(hasOperatorName("!="), hasOperatorName("==")),
-                       isExpandedFromMacro(std::string(CurrName)),
+                       isExpandedFromMacro(CurrName),
                        anyOf(hasLHS(hasType(qualType(
                                  hasCanonicalType(asString("NSString *"))))),
                              hasRHS(hasType(qualType(

clang/docs/LibASTMatchersReference.html

@@ -4222,7 +4222,7 @@ <h2 id="narrowing-matchers">Narrowing Matchers</h2>
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('isExpandedFromMacro0')"><a name="isExpandedFromMacro0Anchor">isExpandedFromMacro</a></td><td>std::string MacroName</td></tr>
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('isExpandedFromMacro0')"><a name="isExpandedFromMacro0Anchor">isExpandedFromMacro</a></td><td>StringRef MacroName</td></tr>
 <tr><td colspan="4" class="doc" id="isExpandedFromMacro0"><pre>Matches statements that are (transitively) expanded from the named macro.
 Does not match if only part of the statement is expanded from that macro or
 if different parts of the statement are expanded from different
@@ -5643,7 +5643,7 @@ <h2 id="narrowing-matchers">Narrowing Matchers</h2>
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('isExpandedFromMacro1')"><a name="isExpandedFromMacro1Anchor">isExpandedFromMacro</a></td><td>std::string MacroName</td></tr>
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('isExpandedFromMacro1')"><a name="isExpandedFromMacro1Anchor">isExpandedFromMacro</a></td><td>StringRef MacroName</td></tr>
 <tr><td colspan="4" class="doc" id="isExpandedFromMacro1"><pre>Matches statements that are (transitively) expanded from the named macro.
 Does not match if only part of the statement is expanded from that macro or
 if different parts of the statement are expanded from different
@@ -5843,7 +5843,7 @@ <h2 id="narrowing-matchers">Narrowing Matchers</h2>
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1TypeLoc.html">TypeLoc</a>&gt;</td><td class="name" onclick="toggle('isExpandedFromMacro2')"><a name="isExpandedFromMacro2Anchor">isExpandedFromMacro</a></td><td>std::string MacroName</td></tr>
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1TypeLoc.html">TypeLoc</a>&gt;</td><td class="name" onclick="toggle('isExpandedFromMacro2')"><a name="isExpandedFromMacro2Anchor">isExpandedFromMacro</a></td><td>StringRef MacroName</td></tr>
 <tr><td colspan="4" class="doc" id="isExpandedFromMacro2"><pre>Matches statements that are (transitively) expanded from the named macro.
 Does not match if only part of the statement is expanded from that macro or
 if different parts of the statement are expanded from different

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -330,7 +330,7 @@ AST_POLYMORPHIC_MATCHER_REGEX(isExpansionInFileMatching,
 /// appearances of the macro.
 AST_POLYMORPHIC_MATCHER_P(isExpandedFromMacro,
                           AST_POLYMORPHIC_SUPPORTED_TYPES(Decl, Stmt, TypeLoc),
-                          std::string, MacroName) {
+                          StringRef, MacroName) {
   // Verifies that the statement' beginning and ending are both expanded from
   // the same instance of the given macro.
   auto& Context = Finder->getASTContext();