[lld] [ELF] adjustOutputSections: don't copy SHF_EXECINSTR when an output does not contain input sections (PR #70911)

[Peter Smith via llvm-commits]

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@@ -1193,8 +1193,8 @@ void LinkerScript::adjustOutputSections() {
     // We do not want to keep any special flags for output section
     // in case it is empty.
     if (isEmpty)
-      sec->flags = flags & ((sec->nonAlloc ? 0 : (uint64_t)SHF_ALLOC) |
-                            SHF_WRITE | SHF_EXECINSTR);
+      sec->flags =
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smithp35 wrote:

Could be worth updating the comment on line 1170
```
  // The other option is to pick flags that minimize the impact the section
  // will have on the rest of the linker. That is why we copy the flags from
  // the previous sections. Only a few flags are needed to keep the impact low.
```
Perhaps
"// We do not propagate SHF_EXECINSTR as in some cases this can lead to executable writeable SHT_NOBITS section."


https://github.com/llvm/llvm-project/pull/70911