PNaCl bitcode: Use function type not ptr-to-function type to declare function

This is a step towards removing TYPE_CODE_POINTER from the types
table.  This will make the format simpler.  It will also make bitcode
files a little smaller, because we won't need to use type IDs for
referring to pointer types.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3671
TEST=test/NaCl/Bitcode/*.ll

Review URL: https://codereview.chromium.org/24049002

2 files changed, 13 insertions, 6 deletions

diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
index 8b8e9072a8..276d1d59b3 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
@@ -945,12 +945,16 @@ bool NaClBitcodeReader::ParseModule(bool Resume) {
         return Error("Invalid MODULE_CODE_FUNCTION record");
       Type *Ty = getTypeByID(Record[0]);
       if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
-      if (!Ty->isPointerTy())
-        return Error("Function not a pointer type!");
-      FunctionType *FTy =
-        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
+      FunctionType *FTy;
+      if (GetPNaClVersion() == 1) {
+        if (!Ty->isPointerTy())
+          return Error("Function not a pointer type!");
+        FTy = dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
+      } else {
+        FTy = dyn_cast<FunctionType>(Ty);
+      }
       if (!FTy)
-        return Error("Function not a pointer to function type!");
+        return Error("Function not declared with a function type!");
 
       Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
                                         "", TheModule);
diff --git a/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp b/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
index 3355bc757c..6280e5ccfc 100644
--- a/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
+++ b/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
@@ -418,7 +418,10 @@ static void WriteModuleInfo(const Module *M, const NaClValueEnumerator &VE,
   SmallVector<unsigned, 64> Vals;
   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
     // FUNCTION:  [type, callingconv, isproto, linkage]
-    Vals.push_back(VE.getTypeID(F->getType()));
+    Type *Ty = F->getType();
+    if (PNaClVersion >= 2)
+      Ty = Ty->getPointerElementType();
+    Vals.push_back(VE.getTypeID(Ty));
     Vals.push_back(GetEncodedCallingConv(F->getCallingConv()));
     Vals.push_back(F->isDeclaration());
     Vals.push_back(getEncodedLinkage(F));