[DebugInfo] Change DIEnumerator payload type from int64_t to APInt

This allows the representation of arbitrarily large enumeration values.
See https://lists.llvm.org/pipermail/llvm-dev/2017-December/119475.html for context.

Reviewed By: andrewrk, aprantl, MaskRay

Differential Revision: https://reviews.llvm.org/D62475

3 files changed, 37 insertions, 22 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 8f7f980..4b8b0ec 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2317,7 +2317,7 @@ Error BitcodeReader::resolveGlobalAndIndirectSymbolInits() {
   return Error::success();
 }
 
-static APInt readWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
+APInt llvm::readWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
   SmallVector<uint64_t, 8> Words(Vals.size());
   transform(Vals, Words.begin(),
                  BitcodeReader::decodeSignRotatedValue);
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index c1fa91d..6ec4416 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1277,14 +1277,24 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     break;
   }
   case bitc::METADATA_ENUMERATOR: {
-    if (Record.size() != 3)
+    if (Record.size() < 3)
       return error("Invalid record");
 
     IsDistinct = Record[0] & 1;
     bool IsUnsigned = Record[0] & 2;
+    bool IsBigInt = Record[0] & 4;
+    APInt Value;
+
+    if (IsBigInt) {
+      const uint64_t BitWidth = Record[1];
+      const size_t NumWords = Record.size() - 3;
+      Value = readWideAPInt(makeArrayRef(&Record[3], NumWords), BitWidth);
+    } else
+      Value = APInt(64, unrotateSign(Record[1]), !IsUnsigned);
+
     MetadataList.assignValue(
-        GET_OR_DISTINCT(DIEnumerator, (Context, unrotateSign(Record[1]),
-                                       IsUnsigned, getMDString(Record[2]))),
+        GET_OR_DISTINCT(DIEnumerator,
+                        (Context, Value, IsUnsigned, getMDString(Record[2]))),
         NextMetadataNo);
     NextMetadataNo++;
     break;
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 1de3ea8..f6d0e40 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1529,12 +1529,32 @@ void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
   Record.clear();
 }
 
+static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
+  if ((int64_t)V >= 0)
+    Vals.push_back(V << 1);
+  else
+    Vals.push_back((-V << 1) | 1);
+}
+
+static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
+  // We have an arbitrary precision integer value to write whose
+  // bit width is > 64. However, in canonical unsigned integer
+  // format it is likely that the high bits are going to be zero.
+  // So, we only write the number of active words.
+  unsigned NumWords = A.getActiveWords();
+  const uint64_t *RawData = A.getRawData();
+  for (unsigned i = 0; i < NumWords; i++)
+    emitSignedInt64(Vals, RawData[i]);
+}
+
 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
                                             SmallVectorImpl<uint64_t> &Record,
                                             unsigned Abbrev) {
-  Record.push_back((N->isUnsigned() << 1) | N->isDistinct());
-  Record.push_back(rotateSign(N->getValue()));
+  const uint64_t IsBigInt = 1 << 2;
+  Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
+  Record.push_back(N->getValue().getBitWidth());
   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
+  emitWideAPInt(Record, N->getValue());
 
   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
   Record.clear();
@@ -2269,13 +2289,6 @@ void ModuleBitcodeWriter::writeSyncScopeNames() {
   Stream.ExitBlock();
 }
 
-static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
-  if ((int64_t)V >= 0)
-    Vals.push_back(V << 1);
-  else
-    Vals.push_back((-V << 1) | 1);
-}
-
 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
                                          bool isGlobal) {
   if (FirstVal == LastVal) return;
@@ -2362,15 +2375,7 @@ void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
         Code = bitc::CST_CODE_INTEGER;
         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
       } else {                             // Wide integers, > 64 bits in size.
-        // We have an arbitrary precision integer value to write whose
-        // bit width is > 64. However, in canonical unsigned integer
-        // format it is likely that the high bits are going to be zero.
-        // So, we only write the number of active words.
-        unsigned NWords = IV->getValue().getActiveWords();
-        const uint64_t *RawWords = IV->getValue().getRawData();
-        for (unsigned i = 0; i != NWords; ++i) {
-          emitSignedInt64(Record, RawWords[i]);
-        }
+        emitWideAPInt(Record, IV->getValue());
         Code = bitc::CST_CODE_WIDE_INTEGER;
       }
     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {