New EH representation for MSVC compatibility

[oota-llvm.git] / lib / Bitcode / Reader / BitstreamReader.cpp

diff --git a/lib/Bitcode/Reader/BitstreamReader.cpp b/lib/Bitcode/Reader/BitstreamReader.cpp
index c88708ce4e83f606a433e62d618f9996f948619c..a103fbdf4a93a317710d171058b9788fb1f46148 100644 (file)
--- a/lib/Bitcode/Reader/BitstreamReader.cpp
+++ b/lib/Bitcode/Reader/BitstreamReader.cpp
@@ -39,51 +39,42 @@ bool BitstreamCursor::EnterSubBlock(unsigned BlockID, unsigned *NumWordsP) {
 
   // Get the codesize of this block.
   CurCodeSize = ReadVBR(bitc::CodeLenWidth);
+  // We can't read more than MaxChunkSize at a time
+  if (CurCodeSize > MaxChunkSize)
+    return true;
+
   SkipToFourByteBoundary();
   unsigned NumWords = Read(bitc::BlockSizeWidth);
   if (NumWordsP) *NumWordsP = NumWords;
 
   // Validate that this block is sane.
-  if (CurCodeSize == 0 || AtEndOfStream())
-    return true;
-
-  return false;
+  return CurCodeSize == 0 || AtEndOfStream();
 }
 
-static void readAbbreviatedLiteral(const BitCodeAbbrevOp &Op,
-                                   SmallVectorImpl<uint64_t> &Vals) {
-  assert(Op.isLiteral() && "Not a literal");
-  // If the abbrev specifies the literal value to use, use it.
-  Vals.push_back(Op.getLiteralValue());
-}
-
-static void readAbbreviatedField(BitstreamCursor &Cursor,
-                                 const BitCodeAbbrevOp &Op,
-                                 SmallVectorImpl<uint64_t> &Vals) {
-  assert(!Op.isLiteral() && "Use ReadAbbreviatedLiteral for literals!");
+static uint64_t readAbbreviatedField(BitstreamCursor &Cursor,
+                                     const BitCodeAbbrevOp &Op) {
+  assert(!Op.isLiteral() && "Not to be used with literals!");
 
   // Decode the value as we are commanded.
-  uint64_t Val;
   switch (Op.getEncoding()) {
   case BitCodeAbbrevOp::Array:
   case BitCodeAbbrevOp::Blob:
     llvm_unreachable("Should not reach here");
   case BitCodeAbbrevOp::Fixed:
-    Val = Cursor.Read((unsigned)Op.getEncodingData());
-    break;
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
+    return Cursor.Read((unsigned)Op.getEncodingData());
   case BitCodeAbbrevOp::VBR:
-    Val = Cursor.ReadVBR64((unsigned)Op.getEncodingData());
-    break;
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
+    return Cursor.ReadVBR64((unsigned)Op.getEncodingData());
   case BitCodeAbbrevOp::Char6:
-    Val = BitCodeAbbrevOp::DecodeChar6(Cursor.Read(6));
-    break;
+    return BitCodeAbbrevOp::DecodeChar6(Cursor.Read(6));
   }
-  Vals.push_back(Val);
+  llvm_unreachable("invalid abbreviation encoding");
 }
 
 static void skipAbbreviatedField(BitstreamCursor &Cursor,
                                  const BitCodeAbbrevOp &Op) {
-  assert(!Op.isLiteral() && "Use ReadAbbreviatedLiteral for literals!");
+  assert(!Op.isLiteral() && "Not to be used with literals!");
 
   // Decode the value as we are commanded.
   switch (Op.getEncoding()) {
@@ -91,9 +82,11 @@ static void skipAbbreviatedField(BitstreamCursor &Cursor,
   case BitCodeAbbrevOp::Blob:
     llvm_unreachable("Should not reach here");
   case BitCodeAbbrevOp::Fixed:
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
     Cursor.Read((unsigned)Op.getEncodingData());
     break;
   case BitCodeAbbrevOp::VBR:
+    assert((unsigned)Op.getEncodingData() <= Cursor.MaxChunkSize);
     Cursor.ReadVBR64((unsigned)Op.getEncodingData());
     break;
   case BitCodeAbbrevOp::Char6:
@@ -179,22 +172,26 @@ unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
   // Read the record code first.
   assert(Abbv->getNumOperandInfos() != 0 && "no record code in abbreviation?");
   const BitCodeAbbrevOp &CodeOp = Abbv->getOperandInfo(0);
+  unsigned Code;
   if (CodeOp.isLiteral())
-    readAbbreviatedLiteral(CodeOp, Vals);
-  else
-    readAbbreviatedField(*this, CodeOp, Vals);
-  unsigned Code = (unsigned)Vals.pop_back_val();
+    Code = CodeOp.getLiteralValue();
+  else {
+    if (CodeOp.getEncoding() == BitCodeAbbrevOp::Array ||
+        CodeOp.getEncoding() == BitCodeAbbrevOp::Blob)
+      report_fatal_error("Abbreviation starts with an Array or a Blob");
+    Code = readAbbreviatedField(*this, CodeOp);
+  }
 
   for (unsigned i = 1, e = Abbv->getNumOperandInfos(); i != e; ++i) {
     const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
     if (Op.isLiteral()) {
-      readAbbreviatedLiteral(Op, Vals);
+      Vals.push_back(Op.getLiteralValue());
       continue;
     }
 
     if (Op.getEncoding() != BitCodeAbbrevOp::Array &&
         Op.getEncoding() != BitCodeAbbrevOp::Blob) {
-      readAbbreviatedField(*this, Op, Vals);
+      Vals.push_back(readAbbreviatedField(*this, Op));
       continue;
     }
 
@@ -203,12 +200,19 @@ unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
       unsigned NumElts = ReadVBR(6);
 
       // Get the element encoding.
-      assert(i+2 == e && "array op not second to last?");
+      if (i + 2 != e)
+        report_fatal_error("Array op not second to last");
       const BitCodeAbbrevOp &EltEnc = Abbv->getOperandInfo(++i);
+      if (!EltEnc.isEncoding())
+        report_fatal_error(
+            "Array element type has to be an encoding of a type");
+      if (EltEnc.getEncoding() == BitCodeAbbrevOp::Array ||
+          EltEnc.getEncoding() == BitCodeAbbrevOp::Blob)
+        report_fatal_error("Array element type can't be an Array or a Blob");
 
       // Read all the elements.
       for (; NumElts; --NumElts)
-        readAbbreviatedField(*this, EltEnc, Vals);
+        Vals.push_back(readAbbreviatedField(*this, EltEnc));
       continue;
     }
 
@@ -253,7 +257,7 @@ void BitstreamCursor::ReadAbbrevRecord() {
   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
   unsigned NumOpInfo = ReadVBR(5);
   for (unsigned i = 0; i != NumOpInfo; ++i) {
-    bool IsLiteral = Read(1) ? true : false;
+    bool IsLiteral = Read(1);
     if (IsLiteral) {
       Abbv->Add(BitCodeAbbrevOp(ReadVBR64(8)));
       continue;
@@ -261,7 +265,7 @@ void BitstreamCursor::ReadAbbrevRecord() {
 
     BitCodeAbbrevOp::Encoding E = (BitCodeAbbrevOp::Encoding)Read(3);
     if (BitCodeAbbrevOp::hasEncodingData(E)) {
-      unsigned Data = ReadVBR64(5);
+      uint64_t Data = ReadVBR64(5);
 
       // As a special case, handle fixed(0) (i.e., a fixed field with zero bits)
       // and vbr(0) as a literal zero.  This is decoded the same way, and avoids
@@ -272,10 +276,18 @@ void BitstreamCursor::ReadAbbrevRecord() {
         continue;
       }
 
+      if ((E == BitCodeAbbrevOp::Fixed || E == BitCodeAbbrevOp::VBR) &&
+          Data > MaxChunkSize)
+        report_fatal_error(
+            "Fixed or VBR abbrev record with size > MaxChunkData");
+
       Abbv->Add(BitCodeAbbrevOp(E, Data));
     } else
       Abbv->Add(BitCodeAbbrevOp(E));
   }
+
+  if (Abbv->getNumOperandInfos() == 0)
+    report_fatal_error("Abbrev record with no operands");
   CurAbbrevs.push_back(Abbv);
 }