Copy clang/Driver/<Option parsing stuff> to llvm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169344 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 1145 insertions, 0 deletions

diff --git a/lib/Option/Arg.cpp b/lib/Option/Arg.cpp
new file mode 100644
index 0000000000..9f547bd825
--- /dev/null
+++ b/lib/Option/Arg.cpp
@@ -0,0 +1,123 @@
+//===--- Arg.cpp - Argument Implementations -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Option/Arg.h"
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+using namespace llvm::opt;
+
+Arg::Arg(const Option _Opt, StringRef S, unsigned _Index, const Arg *_BaseArg)
+  : Opt(_Opt), BaseArg(_BaseArg), Spelling(S), Index(_Index),
+    Claimed(false), OwnsValues(false) {
+}
+
+Arg::Arg(const Option _Opt, StringRef S, unsigned _Index,
+         const char *Value0, const Arg *_BaseArg)
+  : Opt(_Opt), BaseArg(_BaseArg), Spelling(S), Index(_Index),
+    Claimed(false), OwnsValues(false) {
+  Values.push_back(Value0);
+}
+
+Arg::Arg(const Option _Opt, StringRef S, unsigned _Index,
+         const char *Value0, const char *Value1, const Arg *_BaseArg)
+  : Opt(_Opt), BaseArg(_BaseArg), Spelling(S), Index(_Index),
+    Claimed(false), OwnsValues(false) {
+  Values.push_back(Value0);
+  Values.push_back(Value1);
+}
+
+Arg::~Arg() {
+  if (OwnsValues) {
+    for (unsigned i = 0, e = Values.size(); i != e; ++i)
+      delete[] Values[i];
+  }
+}
+
+void Arg::dump() const {
+  llvm::errs() << "<";
+
+  llvm::errs() << " Opt:";
+  Opt.dump();
+
+  llvm::errs() << " Index:" << Index;
+
+  llvm::errs() << " Values: [";
+  for (unsigned i = 0, e = Values.size(); i != e; ++i) {
+    if (i) llvm::errs() << ", ";
+    llvm::errs() << "'" << Values[i] << "'";
+  }
+
+  llvm::errs() << "]>\n";
+}
+
+std::string Arg::getAsString(const ArgList &Args) const {
+  SmallString<256> Res;
+  llvm::raw_svector_ostream OS(Res);
+
+  ArgStringList ASL;
+  render(Args, ASL);
+  for (ArgStringList::iterator
+         it = ASL.begin(), ie = ASL.end(); it != ie; ++it) {
+    if (it != ASL.begin())
+      OS << ' ';
+    OS << *it;
+  }
+
+  return OS.str();
+}
+
+void Arg::renderAsInput(const ArgList &Args, ArgStringList &Output) const {
+  if (!getOption().hasNoOptAsInput()) {
+    render(Args, Output);
+    return;
+  }
+
+  for (unsigned i = 0, e = getNumValues(); i != e; ++i)
+    Output.push_back(getValue(i));
+}
+
+void Arg::render(const ArgList &Args, ArgStringList &Output) const {
+  switch (getOption().getRenderStyle()) {
+  case Option::RenderValuesStyle:
+    for (unsigned i = 0, e = getNumValues(); i != e; ++i)
+      Output.push_back(getValue(i));
+    break;
+
+  case Option::RenderCommaJoinedStyle: {
+    SmallString<256> Res;
+    llvm::raw_svector_ostream OS(Res);
+    OS << getSpelling();
+    for (unsigned i = 0, e = getNumValues(); i != e; ++i) {
+      if (i) OS << ',';
+      OS << getValue(i);
+    }
+    Output.push_back(Args.MakeArgString(OS.str()));
+    break;
+  }
+
+ case Option::RenderJoinedStyle:
+    Output.push_back(Args.GetOrMakeJoinedArgString(
+                       getIndex(), getSpelling(), getValue(0)));
+    for (unsigned i = 1, e = getNumValues(); i != e; ++i)
+      Output.push_back(getValue(i));
+    break;
+
+  case Option::RenderSeparateStyle:
+    Output.push_back(Args.MakeArgString(getSpelling()));
+    for (unsigned i = 0, e = getNumValues(); i != e; ++i)
+      Output.push_back(getValue(i));
+    break;
+  }
+}
diff --git a/lib/Option/ArgList.cpp b/lib/Option/ArgList.cpp
new file mode 100644
index 0000000000..65cb51959e
--- /dev/null
+++ b/lib/Option/ArgList.cpp
@@ -0,0 +1,386 @@
+//===--- ArgList.cpp - Argument List Management ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Option/ArgList.h"
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+using namespace llvm::opt;
+
+void arg_iterator::SkipToNextArg() {
+  for (; Current != Args.end(); ++Current) {
+    // Done if there are no filters.
+    if (!Id0.isValid())
+      break;
+
+    // Otherwise require a match.
+    const Option &O = (*Current)->getOption();
+    if (O.matches(Id0) ||
+        (Id1.isValid() && O.matches(Id1)) ||
+        (Id2.isValid() && O.matches(Id2)))
+      break;
+  }
+}
+
+//
+
+ArgList::ArgList() {
+}
+
+ArgList::~ArgList() {
+}
+
+void ArgList::append(Arg *A) {
+  Args.push_back(A);
+}
+
+void ArgList::eraseArg(OptSpecifier Id) {
+  for (iterator it = begin(), ie = end(); it != ie; ) {
+    if ((*it)->getOption().matches(Id)) {
+      it = Args.erase(it);
+      ie = end();
+    } else {
+      ++it;
+    }
+  }
+}
+
+Arg *ArgList::getLastArgNoClaim(OptSpecifier Id) const {
+  // FIXME: Make search efficient?
+  for (const_reverse_iterator it = rbegin(), ie = rend(); it != ie; ++it)
+    if ((*it)->getOption().matches(Id))
+      return *it;
+  return 0;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1)) {
+      Res = *it;
+      Res->claim();
+
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
+                         OptSpecifier Id2) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1) ||
+        (*it)->getOption().matches(Id2)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
+                         OptSpecifier Id2, OptSpecifier Id3) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1) ||
+        (*it)->getOption().matches(Id2) ||
+        (*it)->getOption().matches(Id3)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
+                         OptSpecifier Id2, OptSpecifier Id3,
+                         OptSpecifier Id4) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1) ||
+        (*it)->getOption().matches(Id2) ||
+        (*it)->getOption().matches(Id3) ||
+        (*it)->getOption().matches(Id4)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
+                         OptSpecifier Id2, OptSpecifier Id3,
+                         OptSpecifier Id4, OptSpecifier Id5) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1) ||
+        (*it)->getOption().matches(Id2) ||
+        (*it)->getOption().matches(Id3) ||
+        (*it)->getOption().matches(Id4) ||
+        (*it)->getOption().matches(Id5)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
+                         OptSpecifier Id2, OptSpecifier Id3,
+                         OptSpecifier Id4, OptSpecifier Id5,
+                         OptSpecifier Id6) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1) ||
+        (*it)->getOption().matches(Id2) ||
+        (*it)->getOption().matches(Id3) ||
+        (*it)->getOption().matches(Id4) ||
+        (*it)->getOption().matches(Id5) ||
+        (*it)->getOption().matches(Id6)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
+                         OptSpecifier Id2, OptSpecifier Id3,
+                         OptSpecifier Id4, OptSpecifier Id5,
+                         OptSpecifier Id6, OptSpecifier Id7) const {
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id0) ||
+        (*it)->getOption().matches(Id1) ||
+        (*it)->getOption().matches(Id2) ||
+        (*it)->getOption().matches(Id3) ||
+        (*it)->getOption().matches(Id4) ||
+        (*it)->getOption().matches(Id5) ||
+        (*it)->getOption().matches(Id6) ||
+        (*it)->getOption().matches(Id7)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
+}
+
+bool ArgList::hasFlag(OptSpecifier Pos, OptSpecifier Neg, bool Default) const {
+  if (Arg *A = getLastArg(Pos, Neg))
+    return A->getOption().matches(Pos);
+  return Default;
+}
+
+StringRef ArgList::getLastArgValue(OptSpecifier Id,
+                                         StringRef Default) const {
+  if (Arg *A = getLastArg(Id))
+    return A->getValue();
+  return Default;
+}
+
+std::vector<std::string> ArgList::getAllArgValues(OptSpecifier Id) const {
+  SmallVector<const char *, 16> Values;
+  AddAllArgValues(Values, Id);
+  return std::vector<std::string>(Values.begin(), Values.end());
+}
+
+void ArgList::AddLastArg(ArgStringList &Output, OptSpecifier Id) const {
+  if (Arg *A = getLastArg(Id)) {
+    A->claim();
+    A->render(*this, Output);
+  }
+}
+
+void ArgList::AddAllArgs(ArgStringList &Output, OptSpecifier Id0,
+                         OptSpecifier Id1, OptSpecifier Id2) const {
+  for (arg_iterator it = filtered_begin(Id0, Id1, Id2),
+         ie = filtered_end(); it != ie; ++it) {
+    (*it)->claim();
+    (*it)->render(*this, Output);
+  }
+}
+
+void ArgList::AddAllArgValues(ArgStringList &Output, OptSpecifier Id0,
+                              OptSpecifier Id1, OptSpecifier Id2) const {
+  for (arg_iterator it = filtered_begin(Id0, Id1, Id2),
+         ie = filtered_end(); it != ie; ++it) {
+    (*it)->claim();
+    for (unsigned i = 0, e = (*it)->getNumValues(); i != e; ++i)
+      Output.push_back((*it)->getValue(i));
+  }
+}
+
+void ArgList::AddAllArgsTranslated(ArgStringList &Output, OptSpecifier Id0,
+                                   const char *Translation,
+                                   bool Joined) const {
+  for (arg_iterator it = filtered_begin(Id0),
+         ie = filtered_end(); it != ie; ++it) {
+    (*it)->claim();
+
+    if (Joined) {
+      Output.push_back(MakeArgString(StringRef(Translation) +
+                                     (*it)->getValue(0)));
+    } else {
+      Output.push_back(Translation);
+      Output.push_back((*it)->getValue(0));
+    }
+  }
+}
+
+void ArgList::ClaimAllArgs(OptSpecifier Id0) const {
+  for (arg_iterator it = filtered_begin(Id0),
+         ie = filtered_end(); it != ie; ++it)
+    (*it)->claim();
+}
+
+void ArgList::ClaimAllArgs() const {
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it)
+    if (!(*it)->isClaimed())
+      (*it)->claim();
+}
+
+const char *ArgList::MakeArgString(const Twine &T) const {
+  SmallString<256> Str;
+  T.toVector(Str);
+  return MakeArgString(Str.str());
+}
+
+const char *ArgList::GetOrMakeJoinedArgString(unsigned Index,
+                                              StringRef LHS,
+                                              StringRef RHS) const {
+  StringRef Cur = getArgString(Index);
+  if (Cur.size() == LHS.size() + RHS.size() &&
+      Cur.startswith(LHS) && Cur.endswith(RHS))
+    return Cur.data();
+
+  return MakeArgString(LHS + RHS);
+}
+
+//
+
+InputArgList::InputArgList(const char* const *ArgBegin,
+                           const char* const *ArgEnd)
+  : NumInputArgStrings(ArgEnd - ArgBegin) {
+  ArgStrings.append(ArgBegin, ArgEnd);
+}
+
+InputArgList::~InputArgList() {
+  // An InputArgList always owns its arguments.
+  for (iterator it = begin(), ie = end(); it != ie; ++it)
+    delete *it;
+}
+
+unsigned InputArgList::MakeIndex(StringRef String0) const {
+  unsigned Index = ArgStrings.size();
+
+  // Tuck away so we have a reliable const char *.
+  SynthesizedStrings.push_back(String0);
+  ArgStrings.push_back(SynthesizedStrings.back().c_str());
+
+  return Index;
+}
+
+unsigned InputArgList::MakeIndex(StringRef String0,
+                                 StringRef String1) const {
+  unsigned Index0 = MakeIndex(String0);
+  unsigned Index1 = MakeIndex(String1);
+  assert(Index0 + 1 == Index1 && "Unexpected non-consecutive indices!");
+  (void) Index1;
+  return Index0;
+}
+
+const char *InputArgList::MakeArgString(StringRef Str) const {
+  return getArgString(MakeIndex(Str));
+}
+
+//
+
+DerivedArgList::DerivedArgList(const InputArgList &_BaseArgs)
+  : BaseArgs(_BaseArgs) {
+}
+
+DerivedArgList::~DerivedArgList() {
+  // We only own the arguments we explicitly synthesized.
+  for (iterator it = SynthesizedArgs.begin(), ie = SynthesizedArgs.end();
+       it != ie; ++it)
+    delete *it;
+}
+
+const char *DerivedArgList::MakeArgString(StringRef Str) const {
+  return BaseArgs.MakeArgString(Str);
+}
+
+Arg *DerivedArgList::MakeFlagArg(const Arg *BaseArg, const Option Opt) const {
+  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
+                                               Twine(Opt.getName())),
+                   BaseArgs.MakeIndex(Opt.getName()), BaseArg);
+  SynthesizedArgs.push_back(A);
+  return A;
+}
+
+Arg *DerivedArgList::MakePositionalArg(const Arg *BaseArg, const Option Opt,
+                                       StringRef Value) const {
+  unsigned Index = BaseArgs.MakeIndex(Value);
+  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
+                                               Twine(Opt.getName())),
+                   Index, BaseArgs.getArgString(Index), BaseArg);
+  SynthesizedArgs.push_back(A);
+  return A;
+}
+
+Arg *DerivedArgList::MakeSeparateArg(const Arg *BaseArg, const Option Opt,
+                                     StringRef Value) const {
+  unsigned Index = BaseArgs.MakeIndex(Opt.getName(), Value);
+  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
+                                               Twine(Opt.getName())),
+                   Index, BaseArgs.getArgString(Index + 1), BaseArg);
+  SynthesizedArgs.push_back(A);
+  return A;
+}
+
+Arg *DerivedArgList::MakeJoinedArg(const Arg *BaseArg, const Option Opt,
+                                   StringRef Value) const {
+  unsigned Index = BaseArgs.MakeIndex(Opt.getName().str() + Value.str());
+  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
+                                               Twine(Opt.getName())), Index,
+                   BaseArgs.getArgString(Index) + Opt.getName().size(),
+                   BaseArg);
+  SynthesizedArgs.push_back(A);
+  return A;
+}
diff --git a/lib/Option/CMakeLists.txt b/lib/Option/CMakeLists.txt
new file mode 100644
index 0000000000..2e7acc27a5
--- /dev/null
+++ b/lib/Option/CMakeLists.txt
@@ -0,0 +1,8 @@
+add_llvm_library(LLVMOption
+  Arg.cpp
+  ArgList.cpp
+  Option.cpp
+  OptTable.cpp
+  )
+
+target_link_libraries(LLVMOption LLVMSupport)
diff --git a/lib/Option/LLVMBuild.txt b/lib/Option/LLVMBuild.txt
new file mode 100644
index 0000000000..0b78cf20c0
--- /dev/null
+++ b/lib/Option/LLVMBuild.txt
@@ -0,0 +1,22 @@
+;===- ./lib/Option/LLVMBuild.txt -------------------------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = Option
+parent = Libraries
+required_libraries = Support
diff --git a/lib/Option/Makefile b/lib/Option/Makefile
new file mode 100644
index 0000000000..255d0796e2
--- /dev/null
+++ b/lib/Option/Makefile
@@ -0,0 +1,14 @@
+##===- lib/Option/Makefile ---------------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../..
+LIBRARYNAME = LLVMOption
+BUILD_ARCHIVE := 1
+
+include $(LEVEL)/Makefile.common
diff --git a/lib/Option/OptTable.cpp b/lib/Option/OptTable.cpp
new file mode 100644
index 0000000000..3b34bf3b3a
--- /dev/null
+++ b/lib/Option/OptTable.cpp
@@ -0,0 +1,388 @@
+//===--- OptTable.cpp - Option Table Implementation -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Option/OptTable.h"
+
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+#include <algorithm>
+#include <map>
+
+using namespace llvm;
+using namespace llvm::opt;
+
+// Ordering on Info. The ordering is *almost* lexicographic, with two
+// exceptions. First, '\0' comes at the end of the alphabet instead of
+// the beginning (thus options precede any other options which prefix
+// them). Second, for options with the same name, the less permissive
+// version should come first; a Flag option should precede a Joined
+// option, for example.
+
+static int StrCmpOptionName(const char *A, const char *B) {
+  char a = *A, b = *B;
+  while (a == b) {
+    if (a == '\0')
+      return 0;
+
+    a = *++A;
+    b = *++B;
+  }
+
+  if (a == '\0') // A is a prefix of B.
+    return 1;
+  if (b == '\0') // B is a prefix of A.
+    return -1;
+
+  // Otherwise lexicographic.
+  return (a < b) ? -1 : 1;
+}
+
+namespace llvm {
+namespace opt {
+
+static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
+  if (&A == &B)
+    return false;
+
+  if (int N = StrCmpOptionName(A.Name, B.Name))
+    return N == -1;
+
+  for (const char * const *APre = A.Prefixes,
+                  * const *BPre = B.Prefixes;
+                          *APre != 0 && *BPre != 0; ++APre, ++BPre) {
+    if (int N = StrCmpOptionName(*APre, *BPre))
+      return N == -1;
+  }
+
+  // Names are the same, check that classes are in order; exactly one
+  // should be joined, and it should succeed the other.
+  assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
+         "Unexpected classes for options with same name.");
+  return B.Kind == Option::JoinedClass;
+}
+
+// Support lower_bound between info and an option name.
+static inline bool operator<(const OptTable::Info &I, const char *Name) {
+  return StrCmpOptionName(I.Name, Name) == -1;
+}
+static inline bool operator<(const char *Name, const OptTable::Info &I) {
+  return StrCmpOptionName(Name, I.Name) == -1;
+}
+}
+}
+
+OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
+
+OptTable::OptTable(const Info *_OptionInfos, unsigned _NumOptionInfos)
+  : OptionInfos(_OptionInfos),
+    NumOptionInfos(_NumOptionInfos),
+    TheInputOptionID(0),
+    TheUnknownOptionID(0),
+    FirstSearchableIndex(0)
+{
+  // Explicitly zero initialize the error to work around a bug in array
+  // value-initialization on MinGW with gcc 4.3.5.
+
+  // Find start of normal options.
+  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
+    unsigned Kind = getInfo(i + 1).Kind;
+    if (Kind == Option::InputClass) {
+      assert(!TheInputOptionID && "Cannot have multiple input options!");
+      TheInputOptionID = getInfo(i + 1).ID;
+    } else if (Kind == Option::UnknownClass) {
+      assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
+      TheUnknownOptionID = getInfo(i + 1).ID;
+    } else if (Kind != Option::GroupClass) {
+      FirstSearchableIndex = i;
+      break;
+    }
+  }
+  assert(FirstSearchableIndex != 0 && "No searchable options?");
+
+#ifndef NDEBUG
+  // Check that everything after the first searchable option is a
+  // regular option class.
+  for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
+    Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
+    assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
+            Kind != Option::GroupClass) &&
+           "Special options should be defined first!");
+  }
+
+  // Check that options are in order.
+  for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
+    if (!(getInfo(i) < getInfo(i + 1))) {
+      getOption(i).dump();
+      getOption(i + 1).dump();
+      llvm_unreachable("Options are not in order!");
+    }
+  }
+#endif
+
+  // Build prefixes.
+  for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
+                i != e; ++i) {
+    if (const char *const *P = getInfo(i).Prefixes) {
+      for (; *P != 0; ++P) {
+        PrefixesUnion.insert(*P);
+      }
+    }
+  }
+
+  // Build prefix chars.
+  for (llvm::StringSet<>::const_iterator I = PrefixesUnion.begin(),
+                                         E = PrefixesUnion.end(); I != E; ++I) {
+    StringRef Prefix = I->getKey();
+    for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
+                                   C != CE; ++C)
+      if (std::find(PrefixChars.begin(), PrefixChars.end(), *C)
+            == PrefixChars.end())
+        PrefixChars.push_back(*C);
+  }
+}
+
+OptTable::~OptTable() {
+}
+
+const Option OptTable::getOption(OptSpecifier Opt) const {
+  unsigned id = Opt.getID();
+  if (id == 0)
+    return Option(0, 0);
+  assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
+  return Option(&getInfo(id), this);
+}
+
+bool OptTable::isOptionHelpHidden(OptSpecifier id) const {
+  return getInfo(id).Flags & HelpHidden;
+}
+
+static bool isInput(const llvm::StringSet<> &Prefixes, StringRef Arg) {
+  if (Arg == "-")
+    return true;
+  for (llvm::StringSet<>::const_iterator I = Prefixes.begin(),
+                                         E = Prefixes.end(); I != E; ++I)
+    if (Arg.startswith(I->getKey()))
+      return false;
+  return true;
+}
+
+/// \returns Matched size. 0 means no match.
+static unsigned matchOption(const OptTable::Info *I, StringRef Str) {
+  for (const char * const *Pre = I->Prefixes; *Pre != 0; ++Pre) {
+    StringRef Prefix(*Pre);
+    if (Str.startswith(Prefix) && Str.substr(Prefix.size()).startswith(I->Name))
+      return Prefix.size() + StringRef(I->Name).size();
+  }
+  return 0;
+}
+
+Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index) const {
+  unsigned Prev = Index;
+  const char *Str = Args.getArgString(Index);
+
+  // Anything that doesn't start with PrefixesUnion is an input, as is '-'
+  // itself.
+  if (isInput(PrefixesUnion, Str))
+    return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
+
+  const Info *Start = OptionInfos + FirstSearchableIndex;
+  const Info *End = OptionInfos + getNumOptions();
+  StringRef Name = StringRef(Str).ltrim(PrefixChars);
+
+  // Search for the first next option which could be a prefix.
+  Start = std::lower_bound(Start, End, Name.data());
+
+  // Options are stored in sorted order, with '\0' at the end of the
+  // alphabet. Since the only options which can accept a string must
+  // prefix it, we iteratively search for the next option which could
+  // be a prefix.
+  //
+  // FIXME: This is searching much more than necessary, but I am
+  // blanking on the simplest way to make it fast. We can solve this
+  // problem when we move to TableGen.
+  for (; Start != End; ++Start) {
+    unsigned ArgSize = 0;
+    // Scan for first option which is a proper prefix.
+    for (; Start != End; ++Start)
+      if ((ArgSize = matchOption(Start, Str)))
+        break;
+    if (Start == End)
+      break;
+
+    // See if this option matches.
+    if (Arg *A = Option(Start, this).accept(Args, Index, ArgSize))
+      return A;
+
+    // Otherwise, see if this argument was missing values.
+    if (Prev != Index)
+      return 0;
+  }
+
+  return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
+}
+
+InputArgList *OptTable::ParseArgs(const char* const *ArgBegin,
+                                  const char* const *ArgEnd,
+                                  unsigned &MissingArgIndex,
+                                  unsigned &MissingArgCount) const {
+  InputArgList *Args = new InputArgList(ArgBegin, ArgEnd);
+
+  // FIXME: Handle '@' args (or at least error on them).
+
+  MissingArgIndex = MissingArgCount = 0;
+  unsigned Index = 0, End = ArgEnd - ArgBegin;
+  while (Index < End) {
+    // Ignore empty arguments (other things may still take them as arguments).
+    if (Args->getArgString(Index)[0] == '\0') {
+      ++Index;
+      continue;
+    }
+
+    unsigned Prev = Index;
+    Arg *A = ParseOneArg(*Args, Index);
+    assert(Index > Prev && "Parser failed to consume argument.");
+
+    // Check for missing argument error.
+    if (!A) {
+      assert(Index >= End && "Unexpected parser error.");
+      assert(Index - Prev - 1 && "No missing arguments!");
+      MissingArgIndex = Prev;
+      MissingArgCount = Index - Prev - 1;
+      break;
+    }
+
+    Args->append(A);
+  }
+
+  return Args;
+}
+
+static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
+  const Option O = Opts.getOption(Id);
+  std::string Name = O.getPrefixedName();
+
+  // Add metavar, if used.
+  switch (O.getKind()) {
+  case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
+    llvm_unreachable("Invalid option with help text.");
+
+  case Option::MultiArgClass:
+    llvm_unreachable("Cannot print metavar for this kind of option.");
+
+  case Option::FlagClass:
+    break;
+
+  case Option::SeparateClass: case Option::JoinedOrSeparateClass:
+    Name += ' ';
+    // FALLTHROUGH
+  case Option::JoinedClass: case Option::CommaJoinedClass:
+  case Option::JoinedAndSeparateClass:
+    if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
+      Name += MetaVarName;
+    else
+      Name += "<value>";
+    break;
+  }
+
+  return Name;
+}
+
+static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
+                                std::vector<std::pair<std::string,
+                                const char*> > &OptionHelp) {
+  OS << Title << ":\n";
+
+  // Find the maximum option length.
+  unsigned OptionFieldWidth = 0;
+  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
+    // Skip titles.
+    if (!OptionHelp[i].second)
+      continue;
+
+    // Limit the amount of padding we are willing to give up for alignment.
+    unsigned Length = OptionHelp[i].first.size();
+    if (Length <= 23)
+      OptionFieldWidth = std::max(OptionFieldWidth, Length);
+  }
+
+  const unsigned InitialPad = 2;
+  for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
+    const std::string &Option = OptionHelp[i].first;
+    int Pad = OptionFieldWidth - int(Option.size());
+    OS.indent(InitialPad) << Option;
+
+    // Break on long option names.
+    if (Pad < 0) {
+      OS << "\n";
+      Pad = OptionFieldWidth + InitialPad;
+    }
+    OS.indent(Pad + 1) << OptionHelp[i].second << '\n';
+  }
+}
+
+static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
+  unsigned GroupID = Opts.getOptionGroupID(Id);
+
+  // If not in a group, return the default help group.
+  if (!GroupID)
+    return "OPTIONS";
+
+  // Abuse the help text of the option groups to store the "help group"
+  // name.
+  //
+  // FIXME: Split out option groups.
+  if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
+    return GroupHelp;
+
+  // Otherwise keep looking.
+  return getOptionHelpGroup(Opts, GroupID);
+}
+
+void OptTable::PrintHelp(raw_ostream &OS, const char *Name,
+                         const char *Title, bool ShowHidden) const {
+  OS << "OVERVIEW: " << Title << "\n";
+  OS << '\n';
+  OS << "USAGE: " << Name << " [options] <inputs>\n";
+  OS << '\n';
+
+  // Render help text into a map of group-name to a list of (option, help)
+  // pairs.
+  typedef std::map<std::string,
+                 std::vector<std::pair<std::string, const char*> > > helpmap_ty;
+  helpmap_ty GroupedOptionHelp;
+
+  for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
+    unsigned Id = i + 1;
+
+    // FIXME: Split out option groups.
+    if (getOptionKind(Id) == Option::GroupClass)
+      continue;
+
+    if (!ShowHidden && isOptionHelpHidden(Id))
+      continue;
+
+    if (const char *Text = getOptionHelpText(Id)) {
+      const char *HelpGroup = getOptionHelpGroup(*this, Id);
+      const std::string &OptName = getOptionHelpName(*this, Id);
+      GroupedOptionHelp[HelpGroup].push_back(std::make_pair(OptName, Text));
+    }
+  }
+
+  for (helpmap_ty::iterator it = GroupedOptionHelp .begin(),
+         ie = GroupedOptionHelp.end(); it != ie; ++it) {
+    if (it != GroupedOptionHelp .begin())
+      OS << "\n";
+    PrintHelpOptionList(OS, it->first, it->second);
+  }
+
+  OS.flush();
+}
diff --git a/lib/Option/Option.cpp b/lib/Option/Option.cpp
new file mode 100644
index 0000000000..003f07f037
--- /dev/null
+++ b/lib/Option/Option.cpp
@@ -0,0 +1,204 @@
+//===--- Option.cpp - Abstract Driver Options -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Option/Option.h"
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/ErrorHandling.h"
+
+#include <algorithm>
+#include <cassert>
+
+using namespace llvm;
+using namespace llvm::opt;
+
+Option::Option(const OptTable::Info *info, const OptTable *owner)
+  : Info(info), Owner(owner) {
+
+  // Multi-level aliases are not supported, and alias options cannot
+  // have groups. This just simplifies option tracking, it is not an
+  // inherent limitation.
+  assert((!Info || !getAlias().isValid() || (!getAlias().getAlias().isValid() &&
+         !getGroup().isValid())) &&
+         "Multi-level aliases and aliases with groups are unsupported.");
+}
+
+Option::~Option() {
+}
+
+void Option::dump() const {
+  llvm::errs() << "<";
+  switch (getKind()) {
+#define P(N) case N: llvm::errs() << #N; break
+    P(GroupClass);
+    P(InputClass);
+    P(UnknownClass);
+    P(FlagClass);
+    P(JoinedClass);
+    P(SeparateClass);
+    P(CommaJoinedClass);
+    P(MultiArgClass);
+    P(JoinedOrSeparateClass);
+    P(JoinedAndSeparateClass);
+#undef P
+  }
+
+  llvm::errs() << " Prefixes:[";
+  for (const char * const *Pre = Info->Prefixes; *Pre != 0; ++Pre) {
+    llvm::errs() << '"' << *Pre << (*(Pre + 1) == 0 ? "\"" : "\", ");
+  }
+  llvm::errs() << ']';
+
+  llvm::errs() << " Name:\"" << getName() << '"';
+
+  const Option Group = getGroup();
+  if (Group.isValid()) {
+    llvm::errs() << " Group:";
+    Group.dump();
+  }
+
+  const Option Alias = getAlias();
+  if (Alias.isValid()) {
+    llvm::errs() << " Alias:";
+    Alias.dump();
+  }
+
+  if (getKind() == MultiArgClass)
+    llvm::errs() << " NumArgs:" << getNumArgs();
+
+  llvm::errs() << ">\n";
+}
+
+bool Option::matches(OptSpecifier Opt) const {
+  // Aliases are never considered in matching, look through them.
+  const Option Alias = getAlias();
+  if (Alias.isValid())
+    return Alias.matches(Opt);
+
+  // Check exact match.
+  if (getID() == Opt.getID())
+    return true;
+
+  const Option Group = getGroup();
+  if (Group.isValid())
+    return Group.matches(Opt);
+  return false;
+}
+
+Arg *Option::accept(const ArgList &Args,
+                    unsigned &Index,
+                    unsigned ArgSize) const {
+  const Option &UnaliasedOption = getUnaliasedOption();
+  StringRef Spelling;
+  // If the option was an alias, get the spelling from the unaliased one.
+  if (getID() == UnaliasedOption.getID()) {
+    Spelling = StringRef(Args.getArgString(Index), ArgSize);
+  } else {
+    Spelling = Args.MakeArgString(Twine(UnaliasedOption.getPrefix()) +
+                                  Twine(UnaliasedOption.getName()));
+  }
+
+  switch (getKind()) {
+  case FlagClass:
+    if (ArgSize != strlen(Args.getArgString(Index)))
+      return 0;
+
+    return new Arg(UnaliasedOption, Spelling, Index++);
+  case JoinedClass: {
+    const char *Value = Args.getArgString(Index) + ArgSize;
+    return new Arg(UnaliasedOption, Spelling, Index++, Value);
+  }
+  case CommaJoinedClass: {
+    // Always matches.
+    const char *Str = Args.getArgString(Index) + ArgSize;
+    Arg *A = new Arg(UnaliasedOption, Spelling, Index++);
+
+    // Parse out the comma separated values.
+    const char *Prev = Str;
+    for (;; ++Str) {
+      char c = *Str;
+
+      if (!c || c == ',') {
+        if (Prev != Str) {
+          char *Value = new char[Str - Prev + 1];
+          memcpy(Value, Prev, Str - Prev);
+          Value[Str - Prev] = '\0';
+          A->getValues().push_back(Value);
+        }
+
+        if (!c)
+          break;
+
+        Prev = Str + 1;
+      }
+    }
+    A->setOwnsValues(true);
+
+    return A;
+  }
+  case SeparateClass:
+    // Matches iff this is an exact match.
+    // FIXME: Avoid strlen.
+    if (ArgSize != strlen(Args.getArgString(Index)))
+      return 0;
+
+    Index += 2;
+    if (Index > Args.getNumInputArgStrings())
+      return 0;
+
+    return new Arg(UnaliasedOption, Spelling,
+                   Index - 2, Args.getArgString(Index - 1));
+  case MultiArgClass: {
+    // Matches iff this is an exact match.
+    // FIXME: Avoid strlen.
+    if (ArgSize != strlen(Args.getArgString(Index)))
+      return 0;
+
+    Index += 1 + getNumArgs();
+    if (Index > Args.getNumInputArgStrings())
+      return 0;
+
+    Arg *A = new Arg(UnaliasedOption, Spelling, Index - 1 - getNumArgs(),
+                      Args.getArgString(Index - getNumArgs()));
+    for (unsigned i = 1; i != getNumArgs(); ++i)
+      A->getValues().push_back(Args.getArgString(Index - getNumArgs() + i));
+    return A;
+  }
+  case JoinedOrSeparateClass: {
+    // If this is not an exact match, it is a joined arg.
+    // FIXME: Avoid strlen.
+    if (ArgSize != strlen(Args.getArgString(Index))) {
+      const char *Value = Args.getArgString(Index) + ArgSize;
+      return new Arg(*this, Spelling, Index++, Value);
+    }
+
+    // Otherwise it must be separate.
+    Index += 2;
+    if (Index > Args.getNumInputArgStrings())
+      return 0;
+
+    return new Arg(UnaliasedOption, Spelling,
+                   Index - 2, Args.getArgString(Index - 1));
+  }
+  case JoinedAndSeparateClass:
+    // Always matches.
+    Index += 2;
+    if (Index > Args.getNumInputArgStrings())
+      return 0;
+
+    return new Arg(UnaliasedOption, Spelling, Index - 2,
+                   Args.getArgString(Index - 2) + ArgSize,
+                   Args.getArgString(Index - 1));
+  default:
+    llvm_unreachable("Invalid option kind!");
+  }
+}