Allow VersionPrinter to print to arbitrary raw_ostreams

Summary:
I would like to add printing of registered targets to clang's version
information.  For this to work correctly, the VersionPrinter logic in
CommandLine.cpp should support printing to arbitrary raw_ostreams,
instead of always defaulting to outs().

Add a raw_ostream& parameter to the function pointer type used for
VersionPrinter, and while doing so, introduce a typedef for convenience.

Note that VersionPrinter::print() will still default to using outs(),
the clang part will necessarily go into a separate review.

Reviewers: beanz, chandlerc, dberris, mehdi_amini, zturner

Reviewed By: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33899

llvm-svn: 304835

llvm/include/llvm/Support/CommandLine.h

@@ -64,12 +64,15 @@ bool ParseCommandLineOptions(int argc, const char *const *argv,
 void ParseEnvironmentOptions(const char *progName, const char *envvar,
                              const char *Overview = "");
 
+// Function pointer type for printing version information.
+typedef std::function<void(raw_ostream &)> VersionPrinterTy;
+
 ///===---------------------------------------------------------------------===//
 /// SetVersionPrinter - Override the default (LLVM specific) version printer
 ///                     used to print out the version when --version is given
 ///                     on the command line. This allows other systems using the
 ///                     CommandLine utilities to print their own version string.
-void SetVersionPrinter(void (*func)());
+void SetVersionPrinter(VersionPrinterTy func);
 
 ///===---------------------------------------------------------------------===//
 /// AddExtraVersionPrinter - Add an extra printer to use in addition to the
@@ -78,7 +81,7 @@ void SetVersionPrinter(void (*func)());
 ///                          which will be called after the basic LLVM version
 ///                          printing is complete. Each can then add additional
 ///                          information specific to the tool.
-void AddExtraVersionPrinter(void (*func)());
+void AddExtraVersionPrinter(VersionPrinterTy func);
 
 // PrintOptionValues - Print option values.
 // With -print-options print the difference between option values and defaults.

llvm/include/llvm/Support/TargetRegistry.h

@@ -598,7 +598,7 @@ struct TargetRegistry {
 
   /// printRegisteredTargetsForVersion - Print the registered targets
   /// appropriately for inclusion in a tool's version output.
-  static void printRegisteredTargetsForVersion();
+  static void printRegisteredTargetsForVersion(raw_ostream &OS);
 
   /// @name Registry Access
   /// @{

llvm/lib/Support/CommandLine.cpp

@@ -2042,9 +2042,9 @@ void CommandLineParser::printOptionValues() {
     Opts[i].second->printOptionValue(MaxArgLen, PrintAllOptions);
 }
 
-static void (*OverrideVersionPrinter)() = nullptr;
+static VersionPrinterTy OverrideVersionPrinter = nullptr;
 
-static std::vector<void (*)()> *ExtraVersionPrinters = nullptr;
+static std::vector<VersionPrinterTy> *ExtraVersionPrinters = nullptr;
 
 namespace {
 class VersionPrinter {
@@ -2084,7 +2084,7 @@ public:
       return;
 
     if (OverrideVersionPrinter != nullptr) {
-      (*OverrideVersionPrinter)();
+      OverrideVersionPrinter(outs());
       exit(0);
     }
     print();
@@ -2093,10 +2093,8 @@ public:
     // information.
     if (ExtraVersionPrinters != nullptr) {
       outs() << '\n';
-      for (std::vector<void (*)()>::iterator I = ExtraVersionPrinters->begin(),
-                                             E = ExtraVersionPrinters->end();
-           I != E; ++I)
-        (*I)();
+      for (auto I : *ExtraVersionPrinters)
+        I(outs());
     }
 
     exit(0);
@@ -2134,11 +2132,11 @@ void cl::PrintHelpMessage(bool Hidden, bool Categorized) {
 /// Utility function for printing version number.
 void cl::PrintVersionMessage() { VersionPrinterInstance.print(); }
 
-void cl::SetVersionPrinter(void (*func)()) { OverrideVersionPrinter = func; }
+void cl::SetVersionPrinter(VersionPrinterTy func) { OverrideVersionPrinter = func; }
 
-void cl::AddExtraVersionPrinter(void (*func)()) {
+void cl::AddExtraVersionPrinter(VersionPrinterTy func) {
   if (!ExtraVersionPrinters)
-    ExtraVersionPrinters = new std::vector<void (*)()>;
+    ExtraVersionPrinters = new std::vector<VersionPrinterTy>;
 
   ExtraVersionPrinters->push_back(func);
 }

llvm/lib/Support/TargetRegistry.cpp

@@ -114,7 +114,7 @@ static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,
   return LHS->first.compare(RHS->first);
 }
 
-void TargetRegistry::printRegisteredTargetsForVersion() {
+void TargetRegistry::printRegisteredTargetsForVersion(raw_ostream &OS) {
   std::vector<std::pair<StringRef, const Target*> > Targets;
   size_t Width = 0;
   for (const auto &T : TargetRegistry::targets()) {
@@ -123,7 +123,6 @@ void TargetRegistry::printRegisteredTargetsForVersion() {
   }
   array_pod_sort(Targets.begin(), Targets.end(), TargetArraySortFn);
 
-  raw_ostream &OS = outs();
   OS << "  Registered Targets:\n";
   for (unsigned i = 0, e = Targets.size(); i != e; ++i) {
     OS << "    " << Targets[i].first;