PNaCl bitcode: Remove handling of USELIST blocks

These blocks are never generated by the PNaCl bitcode writer.  The
code for generating them was removed when BitcodeWriter.cpp was copied
to produce NaClBitcodeWriter.cpp in
5712db994c8a4abb8c2512fb2900650f8335af66.  The same wasn't done when
BitcodeReader.cpp was copied to produce NaClBitcodeReader.cpp, so we
do this now.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3590
TEST=PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/23598005

4 files changed, 1 insertions, 55 deletions

diff --git a/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h b/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h
index b9c358f271..90d482afaf 100644
--- a/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h
+++ b/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h
@@ -43,7 +43,7 @@ namespace naclbitc {
 
     TYPE_BLOCK_ID_NEW,
 
-    USELIST_BLOCK_ID,
+    USELIST_BLOCK_ID,          // Not used in PNaCl.
     GLOBALVAR_BLOCK_ID
   };
 
@@ -323,10 +323,6 @@ namespace naclbitc {
     // PNaCl version 2: CALL_INDIRECT: [cc, fnid, fnty, args...]
     FUNC_CODE_INST_CALL_INDIRECT = 44
   };
-
-  enum NaClUseListCodes {
-    USELIST_CODE_ENTRY = 1   // USELIST_CODE_ENTRY: TBD.
-  };
 } // End naclbitc namespace
 } // End llvm namespace
 
diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
index 9e8c398172..87eab106a0 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
@@ -894,45 +894,6 @@ bool NaClBitcodeReader::ParseConstants() {
   }
 }
 
-bool NaClBitcodeReader::ParseUseLists() {
-  DEBUG(dbgs() << "-> ParseUseLists\n");
-  if (Stream.EnterSubBlock(naclbitc::USELIST_BLOCK_ID))
-    return Error("Malformed block record");
-
-  SmallVector<uint64_t, 64> Record;
-
-  // Read all the records.
-  while (1) {
-    NaClBitstreamEntry Entry = Stream.advanceSkippingSubblocks();
-
-    switch (Entry.Kind) {
-    case NaClBitstreamEntry::SubBlock: // Handled for us already.
-    case NaClBitstreamEntry::Error:
-      return Error("malformed use list block");
-    case NaClBitstreamEntry::EndBlock:
-      DEBUG(dbgs() << "<- ParseUseLists\n");
-      return false;
-    case NaClBitstreamEntry::Record:
-      // The interesting case.
-      break;
-    }
-
-    // Read a use list record.
-    Record.clear();
-    switch (Stream.readRecord(Entry.ID, Record)) {
-    default:  // Default behavior: unknown type.
-      break;
-    case naclbitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
-      unsigned RecordLength = Record.size();
-      if (RecordLength < 1)
-        return Error ("Invalid UseList reader!");
-      UseListRecords.push_back(Record);
-      break;
-    }
-    }
-  }
-}
-
 /// RememberAndSkipFunctionBody - When we see the block for a function body,
 /// remember where it is and then skip it.  This lets us lazily deserialize the
 /// functions.
@@ -1047,10 +1008,6 @@ bool NaClBitcodeReader::ParseModule(bool Resume) {
           return false;
         }
         break;
-      case naclbitc::USELIST_BLOCK_ID:
-        if (ParseUseLists())
-          return true;
-        break;
       }
       continue;
 
diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h
index 762088887f..f69fdbdfd4 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h
@@ -172,7 +172,6 @@ class NaClBitcodeReader : public GVMaterializer {
 
   std::vector<Type*> TypeList;
   NaClBitcodeReaderValueList ValueList;
-  SmallVector<SmallVector<uint64_t, 64>, 64> UseListRecords;
 
   // Holds information about each BasicBlock in the function being read.
   struct BasicBlockInfo {
@@ -366,7 +365,6 @@ private:
   bool RememberAndSkipFunctionBody();
   bool ParseFunctionBody(Function *F);
   bool GlobalCleanup();
-  bool ParseUseLists();
   bool InitStream();
   bool InitStreamFromBuffer();
   bool InitLazyStream();
diff --git a/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp b/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp
index 73b328f118..d5f61c14cd 100644
--- a/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp
+++ b/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp
@@ -273,11 +273,6 @@ static const char *GetCodeName(unsigned CodeID, unsigned BlockID,
     case naclbitc::METADATA_FN_NODE:     return "METADATA_FN_NODE";
     case naclbitc::METADATA_NAMED_NODE:  return "METADATA_NAMED_NODE";
     }
-  case naclbitc::USELIST_BLOCK_ID:
-    switch(CodeID) {
-    default:return 0;
-    case naclbitc::USELIST_CODE_ENTRY:   return "USELIST_CODE_ENTRY";
-    }
   case naclbitc::GLOBALVAR_BLOCK_ID:
     switch (CodeID) {
     default: return 0;