Rebased PNaCl localmods in LLVM to 223109

lib/Transforms/NaCl/AddPNaClExternalDecls.cpp

+//===- AddPNaClExternalDecls.cpp - Add decls for PNaCl external functions -===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass adds function declarations for external functions used by PNaCl.
+// These externals are implemented in native libraries and calls to them are
+// created as part of the translation process.
+//
+// Running this pass is a precondition for running ResolvePNaClIntrinsics. They
+// are separate because one is a ModulePass and the other is a FunctionPass.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/NaClAtomicIntrinsics.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/NaCl.h"
+
+using namespace llvm;
+
+namespace {
+  // This is a module pass because it adds declarations to the module.
+  class AddPNaClExternalDecls : public ModulePass {
+  public:
+    static char ID;
+    AddPNaClExternalDecls() : ModulePass(ID) {
+      initializeAddPNaClExternalDeclsPass(*PassRegistry::getPassRegistry());
+    }
+
+    virtual bool runOnModule(Module &M);
+  };
+}
+
+bool AddPNaClExternalDecls::runOnModule(Module &M) {
+  // Add declarations for a pre-defined set of external functions to the module.
+  // The function names must match the functions implemented in native code (in
+  // pnacl/support). The function types must match the types of the LLVM
+  // intrinsics.
+  // We expect these declarations not to exist in the module before this pass
+  // runs, but don't assert it; it will be handled by the ABI verifier.
+  LLVMContext &C = M.getContext();
+  M.getOrInsertFunction("setjmp",
+                        // return type
+                        Type::getInt32Ty(C),
+                        // arguments
+                        Type::getInt8Ty(C)->getPointerTo(),
+                        NULL);
+  M.getOrInsertFunction("longjmp",
+                        // return type
+                        Type::getVoidTy(C),
+                        // arguments
+                        Type::getInt8Ty(C)->getPointerTo(),
+                        Type::getInt32Ty(C),
+                        NULL);
+
+  // Add Intrinsic declarations needed by ResolvePNaClIntrinsics up front.
+  Intrinsic::getDeclaration(&M, Intrinsic::nacl_setjmp);
+  Intrinsic::getDeclaration(&M, Intrinsic::nacl_longjmp);
+  NaCl::AtomicIntrinsics AI(C);
+  NaCl::AtomicIntrinsics::View V = AI.allIntrinsicsAndOverloads();
+  for (NaCl::AtomicIntrinsics::View::iterator I = V.begin(), E = V.end();
+       I != E; ++I) {
+    I->getDeclaration(&M);
+  }
+  Intrinsic::getDeclaration(&M, Intrinsic::nacl_atomic_is_lock_free);
+
+  return true;
+}
+
+char AddPNaClExternalDecls::ID = 0;
+INITIALIZE_PASS(AddPNaClExternalDecls, "add-pnacl-external-decls",
+                "Add declarations of external functions used by PNaCl",
+                false, false)
+
+ModulePass *llvm::createAddPNaClExternalDeclsPass() {
+  return new AddPNaClExternalDecls();
+}