Re: [PATCH 1/2] perf build: Autodetect minimum required llvm-dev version

[Quentin Monnet]

2024-09-10 15:04 UTC+0100 ~ James Clark <james.clark@xxxxxxxxxx>
> The new LLVM addr2line feature requires a minimum version of 13 to
> compile. Add a feature check for the version so that NO_LLVM=1 doesn't
> need to be explicitly added. Leave the existing llvm feature check
> intact because it's used by tools other than Perf.
>
> This fixes the following compilation error when the llvm-dev version
> doesn't match:
>
>    util/llvm-c-helpers.cpp: In function 'char* llvm_name_for_code(dso*, const char*, u64)':
>    util/llvm-c-helpers.cpp:178:21: error: 'std::remove_reference_t<llvm::DILineInfo>' {aka 'struct llvm::DILineInfo'} has no member named 'StartAddress'
>      178 |   addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0);
>
> Fixes: c3f8644c21df ("perf report: Support LLVM for addr2line()")
> Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
> ---
>   tools/build/Makefile.feature           |  2 +-
>   tools/build/feature/Makefile           |  9 +++++++++
>   tools/build/feature/test-llvm-perf.cpp | 14 ++++++++++++++
>   tools/perf/Makefile.config             |  6 +++---
>   4 files changed, 27 insertions(+), 4 deletions(-)
>   create mode 100644 tools/build/feature/test-llvm-perf.cpp
>
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 0717e96d6a0e..427a9389e26c 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -136,7 +136,7 @@ FEATURE_DISPLAY ?=              \
>            libunwind              \
>            libdw-dwarf-unwind     \
>            libcapstone            \
> -         llvm                   \
> +         llvm-perf              \

Hi! Just a quick question, why remove "llvm" from the list, here?

Quentin