[PATCH] D111199: [Clang][LLVM][Attr] support btf_type_tag attribute

[Yonghong Song via llvm-commits]

On 11/6/21 4:36 PM, Nathan Chancellor via Phabricator wrote:
> nathanchance added a comment.
> 
> I bisected a crash in the Linux kernel down to the reland commit (and it is not fixed as of https://github.com/llvm/llvm-project/commit/2249ecee8d9a6237f51485bd39f01ba031575987):
> 
>    $ git bisect log
>    # bad: [bdaa181007a46d317a1665acb8234eddeee82815] [TwoAddressInstructionPass] Update existing physreg live intervals
>    # good: [d4b1cf8f9c48a49ab808df15c4ab378276a07b82] [OpenMP] Build device runtimes for sm_86
>    git bisect start 'bdaa181007a46d317a1665acb8234eddeee82815' 'd4b1cf8f9c48a49ab808df15c4ab378276a07b82'
>    # good: [f2703c3c3353031de8de8c465a59d31488b11fb3] [DAG] FoldConstantArithmetic - rename NumOps -> NumElts. NFC.
>    git bisect good f2703c3c3353031de8de8c465a59d31488b11fb3
>    # good: [c68183b81e5257186c9403cf91f8b958af7459bc] [gn build] Use `=` for of -fdebug-compilation-dir
>    git bisect good c68183b81e5257186c9403cf91f8b958af7459bc
>    # bad: [2d8ec3c61d3c2d47b303187bb882ca23544f6fc5] [libcxx] [test] Narrow down XFAILs regarding a MSVC mode specific bug to "windows-dll && msvc"
>    git bisect bad 2d8ec3c61d3c2d47b303187bb882ca23544f6fc5
>    # good: [97c899f3c5d9bbff2824b3252b21378bf96f3f3f] [mlir] Add callback to provide a pass pipeline to MlirOptMain
>    git bisect good 97c899f3c5d9bbff2824b3252b21378bf96f3f3f
>    # bad: [4070f305f9a0c488d7177754d77c0b367e8695bf] [mlir][DialectConversion] Legalize all live argument conversions
>    git bisect bad 4070f305f9a0c488d7177754d77c0b367e8695bf
>    # bad: [3466e00716e12e32fdb100e3fcfca5c2b3e8d784] Reland "[Attr] support btf_type_tag attribute"
>    git bisect bad 3466e00716e12e32fdb100e3fcfca5c2b3e8d784
>    # good: [f64580f8d2ce5e1161857f9c89c2eee7a74c5ab8] [AArch64][GISel] Optimize 8 and 16 bit variants of uaddo.
>    git bisect good f64580f8d2ce5e1161857f9c89c2eee7a74c5ab8
>    # first bad commit: [3466e00716e12e32fdb100e3fcfca5c2b3e8d784] Reland "[Attr] support btf_type_tag attribute"

Thanks. I will look at this problem immediately.

> 
> `cvise` spits out:
> 
>    $ cat efi.i
>    typedef unsigned long efi_query_variable_info_t(int);
>    typedef struct {
>      struct {
>        efi_query_variable_info_t __attribute__((regparm(0))) * query_variable_info;
>      };
>    } efi_runtime_services_t;
>    efi_runtime_services_t efi_0;
>    
>    $ clang -m32 -O2 -c -o /dev/null efi.i
>    
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