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

[Kito Cheng 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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kito-cheng wrote:

It's ".L0 " rather than ".L0" in binutils actually

https://github.com/bminor/binutils-gdb/blob/master/include/opcode/riscv.h#L381

Ref: https://github.com/bminor/binutils-gdb/commit/884b49e3a91504b9c5528343823d67f4419b73bb

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