Get rid of some unnecessary llvm::StringRef -> std::string conversions

(as discussed in the commit message of ce1d8e20a708ed031f2336770a41fbe501fe8225
"Adapt to '[ADT] Make StringRef's std::string conversion operator explicit'";
there are more of those that cannot easily be dropped, though).

Change-Id: Ib2e223f7de96ad8859eab165daa759b480326c7b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/88582
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

4 files changed, 17 insertions, 24 deletions

diff --git a/compilerplugins/clang/constantparam.cxx b/compilerplugins/clang/constantparam.cxx
index dd9bddd086c5..71c0f69da61a 100644
--- a/compilerplugins/clang/constantparam.cxx
+++ b/compilerplugins/clang/constantparam.cxx
@@ -275,7 +275,7 @@ bool ConstantParam::VisitCallExpr(const CallExpr * callExpr) {
         std::string callValue = getCallValue(valExpr);
         std::string paramName = i < functionDecl->getNumParams()
                                 ? functionDecl->getParamDecl(i)->getName().str()
-                                : llvm::StringRef("###" + std::to_string(i)).str();
+                                : "###" + std::to_string(i);
         addToCallSet(functionDecl, i, paramName, callValue);
     }
     return true;
@@ -299,7 +299,7 @@ bool ConstantParam::VisitCXXConstructExpr( const CXXConstructExpr* constructExpr
         std::string callValue = getCallValue(valExpr);
         std::string paramName = i < constructorDecl->getNumParams()
                                 ? constructorDecl->getParamDecl(i)->getName().str()
-                                : llvm::StringRef("###" + std::to_string(i)).str();
+                                : "###" + std::to_string(i);
         addToCallSet(constructorDecl, i, paramName, callValue);
     }
     return true;
diff --git a/compilerplugins/clang/finalclasses.cxx b/compilerplugins/clang/finalclasses.cxx
index 1c25b50afffe..4271a0a76f1b 100644
--- a/compilerplugins/clang/finalclasses.cxx
+++ b/compilerplugins/clang/finalclasses.cxx
@@ -70,15 +70,11 @@ private:
     void checkBase(QualType qt);
 };
 
-bool startsWith(const std::string& rStr, const char* pSubStr) {
-    return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
-}
-
 bool ignoreClass(StringRef s)
 {
     // ignore stuff in the standard library, and UNO stuff we can't touch.
-    if (startsWith(s.str(), "rtl::") || startsWith(s.str(), "sal::") || startsWith(s.str(), "com::sun::")
-        || startsWith(s.str(), "std::") || startsWith(s.str(), "boost::")
+    if (s.startswith("rtl::") || s.startswith("sal::") || s.startswith("com::sun::")
+        || s.startswith("std::") || s.startswith("boost::")
         || s == "OString" || s == "OUString" || s == "bad_alloc")
     {
         return true;
@@ -136,8 +132,8 @@ bool FinalClasses::VisitCXXRecordDecl(const CXXRecordDecl* decl)
         return true;
 
     SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(compat::getBeginLoc(decl));
-    std::string filename = getFilenameOfLocation(spellingLocation).str();
-    auto sourceLocation = filename.substr(strlen(SRCDIR)) + ":"
+    auto const filename = getFilenameOfLocation(spellingLocation);
+    auto sourceLocation = filename.substr(strlen(SRCDIR)).str() + ":"
         + std::to_string(compiler.getSourceManager().getSpellingLineNumber(spellingLocation));
     definitionMap.insert( std::pair<std::string,std::string>(s, sourceLocation) );
     return true;
diff --git a/compilerplugins/clang/mergeclasses.cxx b/compilerplugins/clang/mergeclasses.cxx
index 495cdf7010f1..0f0d73d709c2 100644
--- a/compilerplugins/clang/mergeclasses.cxx
+++ b/compilerplugins/clang/mergeclasses.cxx
@@ -80,15 +80,11 @@ public:
     bool VisitCXXRecordDecl( const CXXRecordDecl* decl);
 };
 
-bool startsWith(const std::string& rStr, const char* pSubStr) {
-    return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
-}
-
 bool ignoreClass(StringRef s)
 {
     // ignore stuff in the standard library, and UNO stuff we can't touch.
-    if (startsWith(s.str(), "rtl::") || startsWith(s.str(), "sal::") || startsWith(s.str(), "com::sun::")
-        || startsWith(s.str(), "std::") || startsWith(s.str(), "boost::")
+    if (s.startswith("rtl::") || s.startswith("sal::") || s.startswith("com::sun::")
+        || s.startswith("std::") || s.startswith("boost::")
         || s == "OString" || s == "OUString" || s == "bad_alloc")
     {
         return true;
@@ -149,12 +145,12 @@ bool MergeClasses::VisitCXXRecordDecl(const CXXRecordDecl* decl)
     if (decl->isThisDeclarationADefinition())
     {
         SourceLocation spellingLocation = compiler.getSourceManager().getSpellingLoc(compat::getBeginLoc(decl));
-        std::string filename = getFilenameOfLocation(spellingLocation).str();
+        auto filename = getFilenameOfLocation(spellingLocation);
         filename = filename.substr(strlen(SRCDIR));
         std::string s = decl->getQualifiedNameAsString();
         if (ignoreClass(s))
             return true;
-        definitionMap.insert( std::pair<std::string,std::string>(s, filename) );
+        definitionMap.insert( std::pair<std::string,std::string>(s, filename.str()) );
         for (auto it = decl->bases_begin(); it != decl->bases_end(); ++it)
         {
             const CXXBaseSpecifier spec = *it;
diff --git a/compilerplugins/clang/useuniqueptr.cxx b/compilerplugins/clang/useuniqueptr.cxx
index d0156cac44bb..564e81c442e7 100644
--- a/compilerplugins/clang/useuniqueptr.cxx
+++ b/compilerplugins/clang/useuniqueptr.cxx
@@ -296,12 +296,12 @@ void UseUniquePtr::CheckDeleteExpr(const FunctionDecl* functionDecl, const CXXDe
 }
 
 template<typename T>
-bool any_equal(std::string const & needle, T first) {
+bool any_equal(StringRef needle, T first) {
   return needle == first;
 }
 
 template<typename T, typename... Args>
-bool any_equal(std::string const & needle, T first, Args... args) {
+bool any_equal(StringRef needle, T first, Args... args) {
   return needle == first || any_equal(needle, args...);
 }
 
@@ -500,18 +500,19 @@ void UseUniquePtr::CheckDeleteLocalVar(const FunctionDecl* functionDecl, const C
     if (parentName == "ScBroadcastAreaSlot")
         return;
     // complicated
-    if (any_equal(parentName.str(), "SwFormatField", "FontPropertyBox", "SdFontPropertyBox",
+    if (any_equal(parentName, "SwFormatField", "FontPropertyBox", "SdFontPropertyBox",
         "SwHTMLParser", "PDFWriterImpl", "SbiParser", "DictionaryList", "SwGlossaryHdl", "SwGlossaryGroupDlg"))
         return;
     // ok
-    if (any_equal(parentName.str(), "SbTreeListBox"))
+    if (any_equal(parentName, "SbTreeListBox"))
         return;
 
     if (functionDecl->getIdentifier())
     {
-        std::string name = functionDecl->getName().str();
+        auto name = functionDecl->getName();
+        SmallString<256> buf;
         if (!parentName.empty())
-            name = std::string(parentName) + "::" + name;
+            name = (parentName + "::" + name).toStringRef(buf);
 
         // custom deleters
         if (name == "Proxy_free" || name == "s_free" || name == "binuno_proxy_free")