Assigning and copying command line option objects shouldn't be allowed.

[beanz]

Summary

The default copy and assignment operators for these objects probably don't actually do what the clients intend, so they should be deleted.

Places using the assignment operator to set the value of an option should cast to the option's data type first to call into the override for operator=. Places using the copy constructor just need to be changed to not copy (i.e. passing by const reference instead of value).

[chandlerc]

Seems obviously good. Please commit.

llvm/trunk/include/llvm/Support/CommandLine.h

public:
 
   ParserClass &getParser() { return Parser; }
 
   template <class T> DataType &operator=(const T &Val) {
     this->setValue(Val);
     return this->getValue();
   }
 
+  // Command line options should not be copyable
+  opt(const opt &) LLVM_DELETED_FUNCTION;
+  opt &operator=(const opt &) LLVM_DELETED_FUNCTION;
+
   // One option...
   template <class M0t>
   explicit opt(const M0t &M0)
       : Option(Optional, NotHidden) {
     apply(M0, this);
     done();
   }
 
public:
 
   unsigned getPosition(unsigned optnum) const {
     assert(optnum < this->size() && "Invalid option index");
     return Positions[optnum];
   }
 
   void setNumAdditionalVals(unsigned n) { Option::setNumAdditionalVals(n); }
 
+  // Command line options should not be copyable
+  list(const list &) LLVM_DELETED_FUNCTION;
+  list &operator=(const list &) LLVM_DELETED_FUNCTION;
+
   // One option...
   template <class M0t>
   explicit list(const M0t &M0)
       : Option(ZeroOrMore, NotHidden) {
     apply(M0, this);
     done();
   }
   // Two options...

 public:
   ParserClass &getParser() { return Parser; }
 
   unsigned getPosition(unsigned optnum) const {
     assert(optnum < this->size() && "Invalid option index");
     return Positions[optnum];
   }
 
+  // Command line options should not be copyable
+  bits(const bits &) LLVM_DELETED_FUNCTION;
+  bits &operator=(const bits &) LLVM_DELETED_FUNCTION;
+
   // One option...
   template <class M0t>
   explicit bits(const M0t &M0)
       : Option(ZeroOrMore, NotHidden) {
     apply(M0, this);
     done();
   }
   // Two options...

 
 public:
   void setAliasFor(Option &O) {
     if (AliasFor)
       error("cl::alias must only have one cl::aliasopt(...) specified!");
     AliasFor = &O;
   }
 
+  // Command line options should not be copyable
+  alias(const alias &) LLVM_DELETED_FUNCTION;
+  alias &operator=(const alias &) LLVM_DELETED_FUNCTION;
+
   // One option...
   template <class M0t>
   explicit alias(const M0t &M0)
       : Option(Optional, Hidden), AliasFor(nullptr) {
     apply(M0, this);
     done();
   }
   // Two options...

llvm/trunk/tools/lli/lli.cpp

if (!NoLazyCompilation && RemoteMCJIT) {
     errs() << "warning: remote mcjit does not support lazy compilation\n";
     NoLazyCompilation = true;
   }
   EE->DisableLazyCompilation(NoLazyCompilation);
 
   // If the user specifically requested an argv[0] to pass into the program,
   // do it now.
   if (!FakeArgv0.empty()) {
-    InputFile = FakeArgv0;
+    InputFile = static_cast<std::string>(FakeArgv0);
   } else {
     // Otherwise, if there is a .bc suffix on the executable strip it off, it
     // might confuse the program.
     if (StringRef(InputFile).endswith(".bc"))
       InputFile.erase(InputFile.length() - 3);
   }
 
   // Add the module's name to the start of the vector of arguments to main().

llvm/trunk/tools/llvm-profdata/llvm-profdata.cpp

static void exitWithError(const Twine &Message, StringRef Whence = "") {
   if (!Whence.empty())
     errs() << Whence << ": ";
   errs() << Message << "\n";
   ::exit(1);
 }
 
 enum ProfileKinds { instr, sample };
 
-void mergeInstrProfile(cl::list<std::string> Inputs, StringRef OutputFilename) {
+void mergeInstrProfile(const cl::list<std::string> &Inputs,
+                       StringRef OutputFilename) {
   if (OutputFilename.compare("-") == 0)
     exitWithError("Cannot write indexed profdata format to stdout.");
 
   std::error_code EC;
   raw_fd_ostream Output(OutputFilename.data(), EC, sys::fs::F_None);
   if (EC)
     exitWithError(EC.message(), OutputFilename);
 
for (const auto &I : *Reader)
               Writer.addFunctionCounts(I.Name, I.Hash, I.Counts))
         errs() << Filename << ": " << I.Name << ": " << EC.message() << "\n";
     if (Reader->hasError())
       exitWithError(Reader->getError().message(), Filename);
   }
   Writer.write(Output);
 }
 
-void mergeSampleProfile(cl::list<std::string> Inputs, StringRef OutputFilename,
+void mergeSampleProfile(const cl::list<std::string> &Inputs,
+                        StringRef OutputFilename,
                         sampleprof::SampleProfileFormat OutputFormat) {
   using namespace sampleprof;
   auto WriterOrErr = SampleProfileWriter::create(OutputFilename, OutputFormat);
   if (std::error_code EC = WriterOrErr.getError())
     exitWithError(EC.message(), OutputFilename);
 
   auto Writer = std::move(WriterOrErr.get());
   StringMap<FunctionSamples> ProfileMap;

llvm/trunk/tools/llvm-size/llvm-size.cpp

int main(int argc, char **argv) {
   sys::PrintStackTraceOnErrorSignal();
   PrettyStackTraceProgram X(argc, argv);
 
   llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
   cl::ParseCommandLineOptions(argc, argv, "llvm object size dumper\n");
 
   ToolName = argv[0];
   if (OutputFormatShort.getNumOccurrences())
-    OutputFormat = OutputFormatShort;
+    OutputFormat = static_cast<OutputFormatTy>(OutputFormatShort);
   if (RadixShort.getNumOccurrences())
     Radix = RadixShort;
 
   for (unsigned i = 0; i < ArchFlags.size(); ++i) {
     if (ArchFlags[i] == "all") {
       ArchAll = true;
     } else {
       if (!MachOObjectFile::isValidArch(ArchFlags[i])) {