[llvm] Use StringRef::consume_front (NFC)

Author: kazutakahirata

llvm/lib/ExecutionEngine/Orc/Debugging/DebugInfoSupport.cpp

@@ -105,8 +105,7 @@ llvm::orc::createDWARFContext(LinkGraph &G) {
       auto SecData = getSectionData(Sec);
       auto Name = Sec.getName();
       // DWARFContext expects the section name to not start with a dot
-      if (Name.starts_with("."))
-        Name = Name.drop_front();
+      Name.consume_front(".");
       LLVM_DEBUG(dbgs() << "Creating DWARFContext section " << Name
                         << " with size " << SecData.size() << "\n");
       DWARFSectionData[Name] =

llvm/lib/MC/WasmObjectWriter.cpp

@@ -1526,8 +1526,7 @@ uint64_t WasmObjectWriter::writeOneObject(MCAssembler &Asm,
       StringRef Name = SectionName;
 
       // For user-defined custom sections, strip the prefix
-      if (Name.starts_with(".custom_section."))
-        Name = Name.substr(strlen(".custom_section."));
+      Name.consume_front(".custom_section.");
 
       MCSymbol *Begin = Sec.getBeginSymbol();
       if (Begin) {

llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp

@@ -959,8 +959,7 @@ SPIRVType *SPIRVGlobalRegistry::getOrCreateSPIRVTypeByName(
   // N is the number of elements of the vector.
   Type *Ty;
 
-  if (TypeStr.starts_with("atomic_"))
-    TypeStr = TypeStr.substr(strlen("atomic_"));
+  TypeStr.consume_front("atomic_");
 
   if (TypeStr.starts_with("void")) {
     Ty = Type::getVoidTy(Ctx);
@@ -1007,8 +1006,7 @@ SPIRVType *SPIRVGlobalRegistry::getOrCreateSPIRVTypeByName(
   // Handle "typeN*" or  "type vector[N]*".
   bool IsPtrToVec = TypeStr.consume_back("*");
 
-  if (TypeStr.starts_with(" vector[")) {
-    TypeStr = TypeStr.substr(strlen(" vector["));
+  if (TypeStr.consume_front(" vector[")) {
     TypeStr = TypeStr.substr(0, TypeStr.find(']'));
   }
   TypeStr.getAsInteger(10, VecElts);

llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -2312,8 +2312,7 @@ bool X86AsmParser::ParseIntelDotOperator(IntelExprStateMachine &SM,
 
   // Drop the optional '.'.
   StringRef DotDispStr = Tok.getString();
-  if (DotDispStr.starts_with("."))
-    DotDispStr = DotDispStr.drop_front(1);
+  DotDispStr.consume_front(".");
   StringRef TrailingDot;
 
   // .Imm gets lexed as a real.

llvm/lib/Target/X86/X86InsertPrefetch.cpp

@@ -135,8 +135,7 @@ bool X86InsertPrefetch::findPrefetchInfo(const FunctionSamples *TopSamples,
       int64_t D = static_cast<int64_t>(S_V.second);
       unsigned IID = 0;
       for (const auto &HintType : HintTypes) {
-        if (Name.starts_with(HintType.first)) {
-          Name = Name.drop_front(HintType.first.size());
+        if (Name.consume_front(HintType.first)) {
           IID = HintType.second;
           break;
         }

llvm/lib/TargetParser/ARMTargetParser.cpp

@@ -348,11 +348,7 @@ StringRef ARM::getArchExtName(uint64_t ArchExtKind) {
 }
 
 static bool stripNegationPrefix(StringRef &Name) {
-  if (Name.starts_with("no")) {
-    Name = Name.substr(2);
-    return true;
-  }
-  return false;
+  return Name.consume_front("no");
 }
 
 StringRef ARM::getArchExtFeature(StringRef ArchExt) {

llvm/lib/TargetParser/Triple.cpp

@@ -1208,8 +1208,7 @@ static VersionTuple parseVersionFromName(StringRef Name) {
 VersionTuple Triple::getEnvironmentVersion() const {
   StringRef EnvironmentName = getEnvironmentName();
   StringRef EnvironmentTypeName = getEnvironmentTypeName(getEnvironment());
-  if (EnvironmentName.starts_with(EnvironmentTypeName))
-    EnvironmentName = EnvironmentName.substr(EnvironmentTypeName.size());
+  EnvironmentName.consume_front(EnvironmentTypeName);
 
   return parseVersionFromName(EnvironmentName);
 }

llvm/tools/llvm-ar/llvm-ar.cpp

@@ -1287,8 +1287,7 @@ static const char *matchFlagWithArg(StringRef Expected,
                                     ArrayRef<const char *> Args) {
   StringRef Arg = *ArgIt;
 
-  if (Arg.starts_with("--"))
-    Arg = Arg.substr(2);
+  Arg.consume_front("--");
 
   size_t len = Expected.size();
   if (Arg == Expected) {

llvm/tools/llvm-diff/llvm-diff.cpp

@@ -42,8 +42,7 @@ static std::unique_ptr<Module> readModule(LLVMContext &Context,
 static void diffGlobal(DifferenceEngine &Engine, Module &L, Module &R,
                        StringRef Name) {
   // Drop leading sigils from the global name.
-  if (Name.starts_with("@"))
-    Name = Name.substr(1);
+  Name.consume_front("@");
 
   Function *LFn = L.getFunction(Name);
   Function *RFn = R.getFunction(Name);