Add /reproduce option to lld/COFF

[ruiu]

Summary

This patch adds /reproduce:<path> option to lld/COFF. This is an
lld-specific option, so we can name it freely. I chose /reproduce
over other names (e.g. /lldlinkrepro) for consistency with other lld
ports.

[mstorsjo]

LGTM

lld/trunk/COFF/Driver.cpp

static std::string createResponseFile(const opt::InputArgList &args,
                                       ArrayRef<StringRef> filePaths,
                                       ArrayRef<StringRef> searchPaths) {
   SmallString<0> data;
   raw_svector_ostream os(data);
 
   for (auto *arg : args) {
     switch (arg->getOption().getID()) {
     case OPT_linkrepro:
+    case OPT_reproduce:
     case OPT_INPUT:
     case OPT_defaultlib:
     case OPT_libpath:
     case OPT_manifest:
     case OPT_manifest_colon:
     case OPT_manifestdependency:
     case OPT_manifestfile:
     case OPT_manifestinput:
symtab->forEachSymbol([&](Symbol *s) {
     e.sym = def;
     if (Chunk *c = def->getChunk())
       if (!(c->getOutputCharacteristics() & IMAGE_SCN_MEM_EXECUTE))
         e.data = true;
     config->exports.push_back(e);
   });
 }
 
+// lld has a feature to create a tar file containing all input files as well as
+// all command line options, so that other people can run lld again with exactly
+// the same inputs. This feature is accessible via /linkrepro and /reproduce.
+//
+// /linkrepro and /reproduce are very similar, but /linkrepro takes a directory
+// name while /reproduce takes a full path. We have /linkrepro for compatibility
+// with Microsoft link.exe.
+Optional<std::string> getReproduceFile(const opt::InputArgList &args) {
+  if (auto *arg = args.getLastArg(OPT_reproduce))
+    return std::string(arg->getValue());
+
+  if (auto *arg = args.getLastArg(OPT_linkrepro)) {
+    SmallString<64> path = StringRef(arg->getValue());
+    sys::path::append(path, "repro.tar");
+    return path.str().str();
+  }
+
+  return None;
+}
+
 void LinkerDriver::link(ArrayRef<const char *> argsArr) {
   // Needed for LTO.
   InitializeAllTargetInfos();
   InitializeAllTargets();
   InitializeAllTargetMCs();
   InitializeAllAsmParsers();
   InitializeAllAsmPrinters();
 
if (args.hasArg(OPT_dash_dash_version)) {
     outs() << getLLDVersion() << "\n";
     return;
   }
 
   // Handle /lldmingw early, since it can potentially affect how other
   // options are handled.
   config->mingw = args.hasArg(OPT_lldmingw);
 
-  if (auto *arg = args.getLastArg(OPT_linkrepro)) {
-    SmallString<64> path = StringRef(arg->getValue());
-    sys::path::append(path, "repro.tar");
-
+  // Handle /linkrepro and /reproduce.
+  if (Optional<std::string> path = getReproduceFile(args)) {
     Expected<std::unique_ptr<TarWriter>> errOrWriter =
-        TarWriter::create(path, "repro");
+        TarWriter::create(*path, sys::path::stem(*path));
 
     if (errOrWriter) {
       tar = std::move(*errOrWriter);
     } else {
-      error("/linkrepro: failed to open " + path + ": " +
+      error("/linkrepro: failed to open " + *path + ": " +
             toString(errOrWriter.takeError()));
     }
   }
 
   if (!args.hasArg(OPT_INPUT)) {
     if (args.hasArg(OPT_deffile))
       config->noEntry = true;
     else

lld/trunk/COFF/Options.td

 def driver : P<"driver", "Generate a Windows NT Kernel Mode Driver">;
 def nodefaultlib_all : F<"nodefaultlib">,
     HelpText<"Remove all default libraries">;
 def noentry : F<"noentry">,
     HelpText<"Don't add reference to DllMainCRTStartup; only valid with /dll">;
 def profile : F<"profile">;
 def repro : F<"Brepro">,
     HelpText<"Use a hash of the executable as the PE header timestamp">;
+def reproduce : P<"reproduce",
+    "Dump linker invocation and input files for debugging">;
 def swaprun : P<"swaprun",
   "Comma-separated list of 'cd' or 'net'">;
 def swaprun_cd : F<"swaprun:cd">, Alias<swaprun>, AliasArgs<["cd"]>,
   HelpText<"Make loader run output binary from swap instead of from CD">;
 def swaprun_net : F<"swaprun:net">, Alias<swaprun>, AliasArgs<["net"]>,
   HelpText<"Make loader run output binary from swap instead of from network">;
 def verbose : F<"verbose">;
 def wholearchive_flag : F<"wholearchive">,

lld/trunk/test/COFF/linkrepro.test

 # REQUIRES: x86, shell
 
 # RUN: rm -rf %t.dir
 # RUN: mkdir -p %t.dir/build1 %t.dir/build2 %t.dir/build3
 # RUN: yaml2obj < %p/Inputs/hello32.yaml > %t.obj
 
 # RUN: cd %t.dir/build1
 # RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
 # RUN:   /entry:main@0 /linkrepro:. /out:%t.exe
 # RUN: tar xf repro.tar
 # RUN: diff %t.obj repro/%:t.obj
 # RUN: diff %p/Inputs/std32.lib repro/%:p/Inputs/std32.lib
 # RUN: FileCheck %s --check-prefix=RSP < repro/response.txt
 
+# RUN: cd %t.dir/build1
+# RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
+# RUN:   /entry:main@0 /reproduce:repro2.tar /out:%t.exe
+# RUN: tar xf repro2.tar
+# RUN: diff %t.obj repro2/%:t.obj
+# RUN: diff %p/Inputs/std32.lib repro2/%:p/Inputs/std32.lib
+# RUN: FileCheck %s --check-prefix=RSP < repro2/response.txt
+
 # RUN: cd %t.dir/build2
 # RUN: lld-link %t.obj /libpath:%p/Inputs /defaultlib:std32 /subsystem:console \
 # RUN:   /entry:main@0 /linkrepro:. /out:%t.exe
 # RUN: tar xf repro.tar
 # RUN: diff %t.obj repro/%:t.obj
 # RUN: diff %p/Inputs/std32.lib repro/%:p/Inputs/std32.lib
 # RUN: FileCheck %s --check-prefix=RSP < repro/response.txt