[lld] 6b715e9 - [lld-macho][nfc] Added some notes on deliberate differences btw LD64 vs LLD-MACHO

[Vy Nguyen via llvm-commits]

Author: Vy Nguyen
Date: 2021-10-20T22:41:57-04:00
New Revision: 6b715e9c4d9cc00f59906d48cd57f4c767229093

URL: https://github.com/llvm/llvm-project/commit/6b715e9c4d9cc00f59906d48cd57f4c767229093
DIFF: https://github.com/llvm/llvm-project/commit/6b715e9c4d9cc00f59906d48cd57f4c767229093.diff

LOG: [lld-macho][nfc] Added some notes on deliberate differences btw LD64 vs LLD-MACHO

For future references and to help with debugging crashes, this could be useful.

Differential Revision: https://reviews.llvm.org/D110464

Added: 
    lld/MachO/ld64-vs-lld.rst

Modified: 
    

Removed: 
    


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diff  --git a/lld/MachO/ld64-vs-lld.rst b/lld/MachO/ld64-vs-lld.rst
new file mode 100644
index 0000000000000..af05024ff20b1
--- /dev/null
+++ b/lld/MachO/ld64-vs-lld.rst
@@ -0,0 +1,16 @@
+==================
+LD64 vs LLD-MACHO
+==================
+
+This doc lists all significant deliberate 
diff erences in behavior between LD64 and LLD-MachO.
+
+ObjC symbols treatment
+**********************
+There are 
diff erences in how LLD and LD64 handle ObjC symbols loaded from archives.
+
+- LD64:
+   * Duplicate ObjC symbols from the same archives will not raise an error. LD64 will pick the first one.   
+   * Duplicate ObjC symbols from 
diff erent archives will raise a "duplicate symbol" error.
+- LLD:
+   * Duplicate symbols, regardless of which archives they are from, will raise errors.
+