[llvm] 1389260 - [JITLink][MachO][arm64] Fix error-check order.

[Lang Hames via llvm-commits]

Author: Lang Hames
Date: 2024-02-08T16:55:05-08:00
New Revision: 1389260805ec2ffb74a4fb311e7327c64d9b8f54

URL: https://github.com/llvm/llvm-project/commit/1389260805ec2ffb74a4fb311e7327c64d9b8f54
DIFF: https://github.com/llvm/llvm-project/commit/1389260805ec2ffb74a4fb311e7327c64d9b8f54.diff

LOG: [JITLink][MachO][arm64] Fix error-check order.

The error check should be performed after the iterator increment, not before
it. Thanks to @dcb314 for catching this!

Fixes github.com/apple/swift/issues/81119

Added: 
    

Modified: 
    llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp

Removed: 
    


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diff  --git a/llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp b/llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp
index 809b2d51f05961..556031baaaed50 100644
--- a/llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp
+++ b/llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp
@@ -312,10 +312,10 @@ class MachOLinkGraphBuilder_arm64 : public MachOLinkGraphBuilder {
 
           Addend = SignExtend64(RI.r_symbolnum, 24);
 
+          ++RelItr;
           if (RelItr == RelEnd)
             return make_error<JITLinkError>("Unpaired Addend reloc at " +
                                             formatv("{0:x16}", FixupAddress));
-          ++RelItr;
           RI = getRelocationInfo(RelItr);
 
           MachORelocKind = getRelocationKind(RI);