[llvm] 097b702 - [Coverity] avoid array overflow when use -1 as index.

[via llvm-commits]

Author: Luo, Yuanke
Date: 2023-04-10T15:40:59+08:00
New Revision: 097b70254678d947feaa108c73f11adec27473d9

URL: https://github.com/llvm/llvm-project/commit/097b70254678d947feaa108c73f11adec27473d9
DIFF: https://github.com/llvm/llvm-project/commit/097b70254678d947feaa108c73f11adec27473d9.diff

LOG: [Coverity] avoid array overflow when use -1 as index.

Added: 
    

Modified: 
    llvm/lib/MC/MCRegisterInfo.cpp

Removed: 
    


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diff  --git a/llvm/lib/MC/MCRegisterInfo.cpp b/llvm/lib/MC/MCRegisterInfo.cpp
index 9c88e3be97df0..9f5b08c5cd1cb 100644
--- a/llvm/lib/MC/MCRegisterInfo.cpp
+++ b/llvm/lib/MC/MCRegisterInfo.cpp
@@ -101,8 +101,13 @@ int MCRegisterInfo::getDwarfRegNumFromDwarfEHRegNum(unsigned RegNum) const {
   // a corresponding LLVM register number at all.  So if we can't map the
   // EH register number to an LLVM register number, assume it's just a
   // valid DWARF register number as is.
-  if (std::optional<unsigned> LRegNum = getLLVMRegNum(RegNum, true))
-    return getDwarfRegNum(*LRegNum, false);
+  if (std::optional<unsigned> LRegNum = getLLVMRegNum(RegNum, true)) {
+    int DwarfRegNum = getDwarfRegNum(*LRegNum, false);
+    if (DwarfRegNum == -1)
+      return RegNum;
+    else
+      return DwarfRegNum;
+  }
   return RegNum;
 }