[PATCH] D85774: [XCOFF][AIX] Enable tooling support for 64 bit symbol table parsing

Fri Aug 14 12:38:45 PDT 2020

jasonliu added inline comments.

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Comment at: llvm/test/tools/llvm-objdump/XCOFF/disassemble-symbol-description64.test:13-14
+
+## xcoff-section-headers64.o Compiled with IBM XL C/C++ for AIX, V16.1.0
+## compiler command: xlc -q64 -qtls -o xcoff-section-headers64.o -c test.c
+
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jhenderson wrote:
> I'm not going to stop you checking in a pre-compiled object, as I'm not an XCOFF maintainer, but as you are continuing to add more functionality here, I strongly advise you to write a yaml2obj XCOFF port, to avoid pre-canned binaries. You'll find pre-built binaries extremely inconvenient to work with as you maintain things going forward. Not only that, but they are harmful to the git repository size, especially if you have to occasionally rebuild them.
> 
> Using yaml2obj may also be about the only way you can test most parse failure paths.
> 
> If yaml2obj isn't viable, at least consider llvm-mc or similar, if possible.
I agree that we would want to move away from pre-canned binaries at some point.
When writing a yaml2obj port, we would still require tools such as llvm-readobj and llvm-objdump to make sure our yaml2obj implementation is correct. So we still have a chicken-or-egg problem here. 
I think the current plan is to use pre-canned binary to develop the tooling support first. Then use the verified tooling support to verify XCOFF object file generation from llc. Then we could replace the pre-canned binary with llvm-mc/llc.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D85774/new/

https://reviews.llvm.org/D85774