Introduce the GlobalSelector class in the Indexing library.

GlobalSelector is an ASTContext-independent way to refer to Objective C selectors.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77538 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Index/GlobalSelector.cpp b/lib/Index/GlobalSelector.cpp
new file mode 100644
index 0000000..9b18741
--- /dev/null
+++ b/lib/Index/GlobalSelector.cpp
@@ -0,0 +1,72 @@
+//===-- GlobalSelector.cpp - Cross-translation-unit "token" for selectors -===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  GlobalSelector is a ASTContext-independent way to refer to selectors.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Index/GlobalSelector.h"
+#include "ProgramImpl.h"
+#include "clang/Index/Program.h"
+#include "clang/AST/ASTContext.h"
+using namespace clang;
+using namespace idx;
+
+/// \brief Get the ASTContext-specific selector.
+Selector GlobalSelector::getSelector(ASTContext &AST) const {
+  if (isInvalid())
+    return Selector();
+
+  Selector GlobSel = Selector(reinterpret_cast<uintptr_t>(Val));
+
+  llvm::SmallVector<IdentifierInfo *, 8> Ids;
+  for (unsigned i = 0, e = GlobSel.isUnarySelector() ? 1 : GlobSel.getNumArgs();
+         i != e; ++i) {
+    IdentifierInfo *GlobII = GlobSel.getIdentifierInfoForSlot(i);
+    IdentifierInfo *II = &AST.Idents.get(GlobII->getName(),
+                                       GlobII->getName() + GlobII->getLength());
+    Ids.push_back(II);
+  }
+
+  return AST.Selectors.getSelector(Ids.size(), Ids.data());
+}
+
+/// \brief Get a printable name for debugging purpose.
+std::string GlobalSelector::getPrintableName() const {
+  if (isInvalid())
+    return "<< Invalid >>";
+  
+  Selector GlobSel = Selector(reinterpret_cast<uintptr_t>(Val));
+  return GlobSel.getAsString();
+}
+
+/// \brief Get a GlobalSelector for the ASTContext-specific selector.
+GlobalSelector GlobalSelector::get(Selector Sel, Program &Prog) {
+  if (Sel.isNull())
+    return GlobalSelector();
+
+  ProgramImpl &ProgImpl = *static_cast<ProgramImpl*>(Prog.Impl);
+
+  llvm::SmallVector<IdentifierInfo *, 8> Ids;
+  for (unsigned i = 0, e = Sel.isUnarySelector() ? 1 : Sel.getNumArgs();
+         i != e; ++i) {
+    IdentifierInfo *II = Sel.getIdentifierInfoForSlot(i);
+    IdentifierInfo *GlobII = &ProgImpl.getIdents().get(II->getName(),
+                                               II->getName() + II->getLength());
+    Ids.push_back(GlobII);
+  }
+
+  Selector GlobSel = ProgImpl.getSelectors().getSelector(Ids.size(),Ids.data());
+  return GlobalSelector(GlobSel.getAsOpaquePtr());
+}
+
+unsigned 
+llvm::DenseMapInfo<GlobalSelector>::getHashValue(GlobalSelector Sel) {
+  return DenseMapInfo<void*>::getHashValue(Sel.getAsOpaquePtr());
+}