Clean up static analyzer warnings.

Clang's static analyzer found several potential cases of undefined
behavior, use of un-initialized values, and potentially null pointer
dereferences in tablegen, Support, MC, and ADT. This cleans them up
with specific assertions on the assumptions of the code.

llvm-svn: 224154

2 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Support/ScaledNumber.cpp b/llvm/lib/Support/ScaledNumber.cpp
index 725f4649613..3cd75091caf 100644
--- a/llvm/lib/Support/ScaledNumber.cpp
+++ b/llvm/lib/Support/ScaledNumber.cpp
@@ -169,8 +169,7 @@ static std::string toStringAPFloat(uint64_t D, int E, unsigned Precision) {
   int Shift = 63 - (NewE - E);
   assert(Shift <= LeadingZeros);
   assert(Shift == LeadingZeros || NewE == ScaledNumbers::MaxScale);
-  assert((Shift & (1u << std::numeric_limits<int>::digits)) == 0 &&
-         "undefined behavior");
+  assert(Shift >= 0 && Shift < 64 && "undefined behavior");
   D <<= Shift;
   E = NewE;
 
diff --git a/llvm/lib/Support/raw_ostream.cpp b/llvm/lib/Support/raw_ostream.cpp
index bbbbe4ae8c6..1bcc31b40a4 100644
--- a/llvm/lib/Support/raw_ostream.cpp
+++ b/llvm/lib/Support/raw_ostream.cpp
@@ -312,6 +312,7 @@ raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
     // than the buffer. Directly write the chunk that is a multiple of the
     // preferred buffer size and put the remainder in the buffer.
     if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
+      assert(NumBytes != 0 && "undefined behavior");
       size_t BytesToWrite = Size - (Size % NumBytes);
       write_impl(Ptr, BytesToWrite);
       size_t BytesRemaining = Size - BytesToWrite;