[PATCH] D63167: [Clang] Remove unused -split-dwarf and obsolete -enable-split-dwarf

[Aaron Puchert via Phabricator via cfe-commits]

aaronpuchert added inline comments.


================
Comment at: clang/lib/CodeGen/BackendUtil.cpp:864
   default:
-    if (!CodeGenOpts.SplitDwarfOutput.empty() &&
-        (CodeGenOpts.getSplitDwarfMode() == CodeGenOptions::SplitFileFission)) {
+    if (!CodeGenOpts.SplitDwarfOutput.empty()) {
       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
----------------
aaronpuchert wrote:
> Perhaps I should also check whether `SplitDwarfFile` is empty.
Maybe not. As it is, we just create an empty (but valid) debug info file when we have `-split-dwarf-output` but no `-split-dwarf-file`. This is exactly what `llc` does as well.

```
$ clang -c -g -o clang.o -Xclang -split-dwarf-output -Xclang clang.dwo test.cpp
$ clang -c -S -emit-llvm -g -o test.ll test.cpp
$ llc -filetype=obj -o llc.o -split-dwarf-output llc.dwo test.ll
$ diff <(llvm-dwarfdump clang.o) <(llvm-dwarfdump llc.o)
1c1
< clang.o:      file format ELF64-x86-64
---
> llc.o:        file format ELF64-x86-64
$ diff clang.dwo llc.dwo
```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D63167/new/

https://reviews.llvm.org/D63167