From 46e2f89364ce24a06953d08c78218fb5548a9fa3 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Wed, 8 Jan 2020 17:13:54 +0000
Subject: [PATCH] [MC] writeFragment - assert MCFragment::FT_Fill length is
 legal.

Silence (clang/MSVC) static analyzer warnings that the fragment data may either write out of bounds of the local array or reference uninitialized data.
---
 llvm/lib/MC/MCAssembler.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index 4a8421299f65..b30137aafb8d 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -572,6 +572,7 @@ static void writeFragment(raw_ostream &OS, const MCAssembler &Asm,
     unsigned VSize = FF.getValueSize();
     const unsigned MaxChunkSize = 16;
     char Data[MaxChunkSize];
+    assert(0 < VSize && VSize <= MaxChunkSize && "Illegal fragment fill size");
     // Duplicate V into Data as byte vector to reduce number of
     // writes done. As such, do endian conversion here.
     for (unsigned I = 0; I != VSize; ++I) {