Flang does not support -fdata-sections and -ffunction-sections flags

[arrowd]

libxsmm tries to call the Fortran compiler with these flags: https://github.com/libxsmm/libxsmm/blob/eea23a9942932d51ca9e06f24711275577663c25/Makefile.inc#L1991

This yields the following error with Flang:

flang-21: error: unknown argument '-fdata-sections'; did you mean '-Xclang -fdata-sections'?
flang-21: error: unknown argument '-ffunction-sections'; did you mean '-Xclang -ffunction-sections'?

It seems that these flags can be easily supported by proxying them to some underlying layer?

[llvmbot]

@llvm/issue-subscribers-flang-driver

Author: Gleb Popov (arrowd)

libxsmm tries to call the Fortran compiler with these flags: https://github.com/libxsmm/libxsmm/blob/eea23a9942932d51ca9e06f24711275577663c25/Makefile.inc#L1991

This yields the following error with Flang:

flang-21: error: unknown argument '-fdata-sections'; did you mean '-Xclang -fdata-sections'?
flang-21: error: unknown argument '-ffunction-sections'; did you mean '-Xclang -ffunction-sections'?

It seems that these flags can be easily supported by proxying them to some underlying layer?

[arrowd]

In a different project:

flang-21: error: unknown argument '-fno-builtin'; did you mean '-Xclang -fno-builtin'?

[tarunprabhu]

In a different project:

flang-21: error: unknown argument '-fno-builtin'; did you mean '-Xclang -fno-builtin'?

Thanks for the bug reports. Do you mind filing separate issues for unrelated command line options that you would like supported? It makes it easier for us to track these.

I am looking into adding support for -fdata-sections and -ffunction-sections