[PATCH] D59780: Support Intel Control-flow Enforcement Technology

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added inline comments.


================
Comment at: lld/ELF/Driver.cpp:1706
     } else if (!features && config->requireCET)
       error(toString(f) + ": --require-cet: file is not compatible with CET");
     ret &= features;
----------------
xiangzhangllvm wrote:
> I don't know why "--forece-bti" use "warn" not "error", in my eyes, people use --require-cet to generate the output file, mostly means, they want to run the output file on a CET-checked machine. It will run fail when linked Non-CET object files to the output file.  So here we used "error" instead of "warn". 
GNU ld supports `-z cet-report=[none|warning|error]` (added in 2019-04) https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=233a00833b984319d5e94db3f5d5d9a735edc984

Examples:

```
% ld.bfd ... -z cet-report=error              # exit code: 1
./ld-new: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/Scrt1.o: error: missing SHSTK property
./ld-new: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crti.o: error: missing SHSTK property
% ld.bfd ... -z cet-report=warning        # exit code: 0
./ld-new: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/Scrt1.o: warning: missing SHSTK property
./ld-new: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crti.o: warning: missing SHSTK property
```


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D59780