[lld] StringRef::{starts,ends}with => {starts,ends}_with. NFC

The latter form is now preferred to be similar to C++20 starts_with.
This replacement also removes one function call when startswith is not inlined.

Author: MaskRay

lld/COFF/Chunks.cpp

@@ -703,7 +703,7 @@ ArrayRef<uint8_t> SectionChunk::consumeDebugMagic(ArrayRef<uint8_t> data,
   if (data.size() < 4)
     fatal("the section is too short: " + sectionName);
 
-  if (!sectionName.startswith(".debug$"))
+  if (!sectionName.starts_with(".debug$"))
     fatal("invalid section: " + sectionName);
 
   uint32_t magic = support::endian::read32le(data.data());

lld/COFF/Chunks.h

@@ -261,12 +261,12 @@ class SectionChunk final : public Chunk {
   // True if this is a codeview debug info chunk. These will not be laid out in
   // the image. Instead they will end up in the PDB, if one is requested.
   bool isCodeView() const {
-    return getSectionName() == ".debug" || getSectionName().startswith(".debug$");
+    return getSectionName() == ".debug" || getSectionName().starts_with(".debug$");
   }
 
   // True if this is a DWARF debug info or exception handling chunk.
   bool isDWARF() const {
-    return getSectionName().startswith(".debug_") || getSectionName() == ".eh_frame";
+    return getSectionName().starts_with(".debug_") || getSectionName() == ".eh_frame";
   }
 
   // Allow iteration over the bodies of this chunk's relocated symbols.

lld/COFF/Driver.cpp

@@ -113,12 +113,12 @@ static std::string getOutputPath(StringRef path, bool isDll, bool isDriver) {
 
 // Returns true if S matches /crtend.?\.o$/.
 static bool isCrtend(StringRef s) {
-  if (!s.endswith(".o"))
+  if (!s.ends_with(".o"))
     return false;
   s = s.drop_back(2);
-  if (s.endswith("crtend"))
+  if (s.ends_with("crtend"))
     return true;
-  return !s.empty() && s.drop_back().endswith("crtend");
+  return !s.empty() && s.drop_back().ends_with("crtend");
 }
 
 // ErrorOr is not default constructible, so it cannot be used as the type
@@ -354,7 +354,7 @@ void LinkerDriver::enqueueArchiveMember(const Archive::Child &c,
 }
 
 bool LinkerDriver::isDecorated(StringRef sym) {
-  return sym.startswith("@") || sym.contains("@@") || sym.startswith("?") ||
+  return sym.starts_with("@") || sym.contains("@@") || sym.starts_with("?") ||
          (!ctx.config.mingw && sym.contains('@'));
 }
 
@@ -1085,7 +1085,7 @@ bool LinkerDriver::run() {
 void LinkerDriver::parseOrderFile(StringRef arg) {
   // For some reason, the MSVC linker requires a filename to be
   // preceded by "@".
-  if (!arg.startswith("@")) {
+  if (!arg.starts_with("@")) {
     error("malformed /order option: '@' missing");
     return;
   }
@@ -1778,7 +1778,7 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
         doGC = true;
       } else if (s == "noref") {
         doGC = false;
-      } else if (s == "icf" || s.startswith("icf=")) {
+      } else if (s == "icf" || s.starts_with("icf=")) {
         icfLevel = ICFLevel::All;
       } else if (s == "safeicf") {
         icfLevel = ICFLevel::Safe;

lld/COFF/DriverUtils.cpp

@@ -322,7 +322,7 @@ void LinkerDriver::parseSwaprun(StringRef arg) {
     else
       error("/swaprun: invalid argument: " + swaprun);
     // To catch trailing commas, e.g. `/spawrun:cd,`
-    if (newArg.empty() && arg.endswith(","))
+    if (newArg.empty() && arg.ends_with(","))
       error("/swaprun: missing argument");
     arg = newArg;
   } while (!arg.empty());
@@ -592,7 +592,7 @@ Export LinkerDriver::parseExport(StringRef arg) {
       e.isPrivate = true;
       continue;
     }
-    if (tok.startswith("@")) {
+    if (tok.starts_with("@")) {
       int32_t ord;
       if (tok.substr(1).getAsInteger(0, ord))
         goto err;
@@ -616,9 +616,9 @@ static StringRef undecorate(COFFLinkerContext &ctx, StringRef sym) {
   // as-is with the leading underscore (with type IMPORT_NAME).
   // In MinGW mode, a decorated stdcall function gets the underscore
   // removed, just like normal cdecl functions.
-  if (sym.startswith("_") && sym.contains('@') && !ctx.config.mingw)
+  if (sym.starts_with("_") && sym.contains('@') && !ctx.config.mingw)
     return sym;
-  return sym.startswith("_") ? sym.substr(1) : sym;
+  return sym.starts_with("_") ? sym.substr(1) : sym;
 }
 
 // Convert stdcall/fastcall style symbols into unsuffixed symbols,
@@ -628,8 +628,8 @@ static StringRef killAt(StringRef sym, bool prefix) {
     return sym;
   // Strip any trailing stdcall suffix
   sym = sym.substr(0, sym.find('@', 1));
-  if (!sym.startswith("@")) {
-    if (prefix && !sym.startswith("_"))
+  if (!sym.starts_with("@")) {
+    if (prefix && !sym.starts_with("_"))
       return saver().save("_" + sym);
     return sym;
   }

lld/COFF/ICF.cpp

@@ -93,7 +93,7 @@ bool ICF::isEligible(SectionChunk *c) {
     return true;
 
   // So are vtables.
-  if (c->sym && c->sym->getName().startswith("??_7"))
+  if (c->sym && c->sym->getName().starts_with("??_7"))
     return true;
 
   // Anything else not in an address-significance table is eligible.
@@ -132,7 +132,7 @@ bool ICF::assocEquals(const SectionChunk *a, const SectionChunk *b) {
   // debug info and CFGuard metadata.
   auto considerForICF = [](const SectionChunk &assoc) {
     StringRef Name = assoc.getSectionName();
-    return !(Name.startswith(".debug") || Name == ".gfids$y" ||
+    return !(Name.starts_with(".debug") || Name == ".gfids$y" ||
              Name == ".giats$y" || Name == ".gljmp$y");
   };
   auto ra = make_filter_range(a->children(), considerForICF);

lld/COFF/InputFiles.cpp

@@ -237,7 +237,7 @@ SectionChunk *ObjFile::readSection(uint32_t sectionNumber,
   // and then write it to a separate .pdb file.
 
   // Ignore DWARF debug info unless /debug is given.
-  if (!ctx.config.debug && name.startswith(".debug_"))
+  if (!ctx.config.debug && name.starts_with(".debug_"))
     return nullptr;
 
   if (sec->Characteristics & llvm::COFF::IMAGE_SCN_LNK_REMOVE)
@@ -261,12 +261,12 @@ SectionChunk *ObjFile::readSection(uint32_t sectionNumber,
   else if (name == ".sxdata")
     sxDataChunks.push_back(c);
   else if (ctx.config.tailMerge && sec->NumberOfRelocations == 0 &&
-           name == ".rdata" && leaderName.startswith("??_C@"))
+           name == ".rdata" && leaderName.starts_with("??_C@"))
     // COFF sections that look like string literal sections (i.e. no
     // relocations, in .rdata, leader symbol name matches the MSVC name mangling
     // for string literals) are subject to string tail merging.
     MergeChunk::addSection(ctx, c);
-  else if (name == ".rsrc" || name.startswith(".rsrc$"))
+  else if (name == ".rsrc" || name.starts_with(".rsrc$"))
     resourceChunks.push_back(c);
   else
     chunks.push_back(c);
@@ -366,7 +366,7 @@ Symbol *ObjFile::createRegular(COFFSymbolRef sym) {
     // everything should be fine. If something actually refers to the symbol
     // (e.g. the undefined weak alias), linking will fail due to undefined
     // references at the end.
-    if (ctx.config.mingw && name.startswith(".weak."))
+    if (ctx.config.mingw && name.starts_with(".weak."))
       return nullptr;
     return ctx.symtab.addUndefined(name, this, false);
   }

lld/COFF/MinGW.cpp

@@ -144,10 +144,10 @@ bool AutoExporter::shouldExport(Defined *sym) const {
     return false;
 
   for (StringRef prefix : excludeSymbolPrefixes.keys())
-    if (sym->getName().startswith(prefix))
+    if (sym->getName().starts_with(prefix))
       return false;
   for (StringRef suffix : excludeSymbolSuffixes.keys())
-    if (sym->getName().endswith(suffix))
+    if (sym->getName().ends_with(suffix))
       return false;
 
   // If a corresponding __imp_ symbol exists and is defined, don't export it.

lld/COFF/PDB.cpp

@@ -1213,8 +1213,8 @@ void PDBLinker::addPublicsToPDB() {
         // Drop the '_' prefix for x86.
         if (ctx.config.machine == I386)
           name = name.drop_front(1);
-        if (name.startswith("__profd_") || name.startswith("__profc_") ||
-            name.startswith("__covrec_")) {
+        if (name.starts_with("__profd_") || name.starts_with("__profc_") ||
+            name.starts_with("__covrec_")) {
           return;
         }
       }
@@ -1469,7 +1469,7 @@ static void addLinkerModuleCoffGroup(PartialSection *sec,
   // Somehow .idata sections & sections groups in the debug symbol stream have
   // the "write" flag set. However the section header for the corresponding
   // .idata section doesn't have it.
-  if (cgs.Name.startswith(".idata"))
+  if (cgs.Name.starts_with(".idata"))
     cgs.Characteristics |= llvm::COFF::IMAGE_SCN_MEM_WRITE;
 
   mod.addSymbol(codeview::SymbolSerializer::writeOneSymbol(

lld/COFF/SymbolTable.cpp

@@ -317,7 +317,7 @@ void SymbolTable::loadMinGWSymbols() {
     }
 
     if (ctx.config.autoImport) {
-      if (name.startswith("__imp_"))
+      if (name.starts_with("__imp_"))
         continue;
       // If we have an undefined symbol, but we have a lazy symbol we could
       // load, load it.
@@ -333,7 +333,7 @@ void SymbolTable::loadMinGWSymbols() {
 }
 
 Defined *SymbolTable::impSymbol(StringRef name) {
-  if (name.startswith("__imp_"))
+  if (name.starts_with("__imp_"))
     return nullptr;
   return dyn_cast_or_null<Defined>(find(("__imp_" + name).str()));
 }
@@ -456,7 +456,7 @@ void SymbolTable::reportUnresolvable() {
     if (undef->getWeakAlias())
       continue;
     StringRef name = undef->getName();
-    if (name.startswith("__imp_")) {
+    if (name.starts_with("__imp_")) {
       Symbol *imp = find(name.substr(strlen("__imp_")));
       if (imp && isa<Defined>(imp))
         continue;
@@ -504,7 +504,7 @@ void SymbolTable::resolveRemainingUndefines() {
 
     // If we can resolve a symbol by removing __imp_ prefix, do that.
     // This odd rule is for compatibility with MSVC linker.
-    if (name.startswith("__imp_")) {
+    if (name.starts_with("__imp_")) {
       Symbol *imp = find(name.substr(strlen("__imp_")));
       if (imp && isa<Defined>(imp)) {
         auto *d = cast<Defined>(imp);
@@ -816,9 +816,9 @@ std::vector<Symbol *> SymbolTable::getSymsWithPrefix(StringRef prefix) {
   std::vector<Symbol *> syms;
   for (auto pair : symMap) {
     StringRef name = pair.first.val();
-    if (name.startswith(prefix) || name.startswith(prefix.drop_front()) ||
-        name.drop_front().startswith(prefix) ||
-        name.drop_front().startswith(prefix.drop_front())) {
+    if (name.starts_with(prefix) || name.starts_with(prefix.drop_front()) ||
+        name.drop_front().starts_with(prefix) ||
+        name.drop_front().starts_with(prefix.drop_front())) {
       syms.push_back(pair.second);
     }
   }
@@ -846,7 +846,7 @@ Symbol *SymbolTable::findMangle(StringRef name) {
   auto findByPrefix = [&syms](const Twine &t) -> Symbol * {
     std::string prefix = t.str();
     for (auto *s : syms)
-      if (s->getName().startswith(prefix))
+      if (s->getName().starts_with(prefix))
         return s;
     return nullptr;
   };
@@ -855,7 +855,7 @@ Symbol *SymbolTable::findMangle(StringRef name) {
   if (ctx.config.machine != I386)
     return findByPrefix("?" + name + "@@Y");
 
-  if (!name.startswith("_"))
+  if (!name.starts_with("_"))
     return nullptr;
   // Search for x86 stdcall function.
   if (Symbol *s = findByPrefix(name + "@"))

lld/COFF/Writer.cpp

@@ -736,7 +736,7 @@ void Writer::fixPartialSectionChars(StringRef name, uint32_t chars) {
     PartialSection *pSec = it.second;
     StringRef curName = pSec->name;
     if (!curName.consume_front(name) ||
-        (!curName.empty() && !curName.startswith("$")))
+        (!curName.empty() && !curName.starts_with("$")))
       continue;
     if (pSec->characteristics == chars)
       continue;
@@ -769,7 +769,7 @@ bool Writer::fixGnuImportChunks() {
   // with alphabetical ordering of the object files within a library.
   for (auto it : partialSections) {
     PartialSection *pSec = it.second;
-    if (!pSec->name.startswith(".idata"))
+    if (!pSec->name.starts_with(".idata"))
       continue;
 
     if (!pSec->chunks.empty())
@@ -857,9 +857,9 @@ static bool shouldStripSectionSuffix(SectionChunk *sc, StringRef name,
     return false;
   if (!sc || !sc->isCOMDAT())
     return false;
-  return name.startswith(".text$") || name.startswith(".data$") ||
-         name.startswith(".rdata$") || name.startswith(".pdata$") ||
-         name.startswith(".xdata$") || name.startswith(".eh_frame$");
+  return name.starts_with(".text$") || name.starts_with(".data$") ||
+         name.starts_with(".rdata$") || name.starts_with(".pdata$") ||
+         name.starts_with(".xdata$") || name.starts_with(".eh_frame$");
 }
 
 void Writer::sortSections() {
@@ -924,7 +924,7 @@ void Writer::createSections() {
     if (shouldStripSectionSuffix(sc, name, ctx.config.mingw))
       name = name.split('$').first;
 
-    if (name.startswith(".tls"))
+    if (name.starts_with(".tls"))
       tlsAlignment = std::max(tlsAlignment, c->getAlignment());
 
     PartialSection *pSec = createPartialSection(name,
@@ -985,7 +985,7 @@ void Writer::createSections() {
       // Move discardable sections named .debug_ to the end, after other
       // discardable sections. Stripping only removes the sections named
       // .debug_* - thus try to avoid leaving holes after stripping.
-      if (s->name.startswith(".debug_"))
+      if (s->name.starts_with(".debug_"))
         return 3;
       return 2;
     }
@@ -1143,7 +1143,7 @@ void Writer::createExportTable() {
   }
   // Warn on exported deleting destructor.
   for (auto e : ctx.config.exports)
-    if (e.sym && e.sym->getName().startswith("??_G"))
+    if (e.sym && e.sym->getName().starts_with("??_G"))
       warn("export of deleting dtor: " + toString(ctx, *e.sym));
 }