[lld] [llvm] [MC] Rename temporary symbols of empty name to ".L0 " (PR #89693)

[Fangrui Song via llvm-commits]

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@@ -725,7 +725,13 @@ void ELFWriter::computeSymbolTable(
         HasLargeSectionIndex = true;
     }
 
+    // Temporary symbols generated for certain assembler features (.eh_frame,
+    // .debug_line) of an empty name may be referenced by relocations due to
+    // linker relaxation. Rename them to ".L0" to match the gas fake label name
+    // and allow ld/objcopy --discard-locals to discard such symbols.
     StringRef Name = Symbol.getName();
+    if (Name.empty())
+      Name = ".L0";
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MaskRay wrote:

I assume that fake labels `.L0\x01` for other ports cannot be retained in .symtab . Even if they do, LLVM likely doesn't want to customize on this.

https://github.com/llvm/llvm-project/pull/89693