[all-commits] [llvm/llvm-project] 876df7: [flang][driver] Allow main program to be in an arc...

[Shao-Ce SUN via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 876df74dd47196a9ca3b4fff21ffb5441491a0a0
      https://github.com/llvm/llvm-project/commit/876df74dd47196a9ca3b4fff21ffb5441491a0a0
  Author: Shao-Ce SUN <sunshaoce at iscas.ac.cn>
  Date:   2023-04-28 (Fri, 28 Apr 2023)

  Changed paths:
    M clang/lib/Driver/ToolChains/Gnu.cpp
    M flang/docs/FlangDriver.md
    M flang/test/CMakeLists.txt
    A flang/test/Driver/link-c-main.c
    A flang/test/Driver/link-f90-main.f90
    M flang/test/Driver/linker-flags.f90

  Log Message:
  -----------
  [flang][driver] Allow main program to be in an archive

Add --undefined=_QQmain to the link line, so that a Fortran main program
will be included in the link job even if it is in an archive (unless we
are building a shared object). For now, this is only applied to the Gnu
toolchain.

We also add a section on the linker invocation to docs/FlangDriver.md.

The new tests require llvm-ar to construct an archive we can include in
the link job. This is a new dependency for flang/test (which already
depends on similar tools such as llvm-objdump).

See discussions in
https://github.com/llvm/llvm-project/issues/54787
which this patch fixes.

Reviewed By: awarzynski

Differential Revision: https://reviews.llvm.org/D134821