Merge bitcoin/bitcoin#27628: build: Fix shared lib linking for darwin with lld

67aacc73ea427f89f005ae17d5fd1572409e649e build: cleanup comments after adding yet another libtool hack (Cory Fields)
283d95516a11166631818dd448ed53a2374b5db8 build: Fix shared lib linking for darwin with lld (Cory Fields)

Pull request description:

  Solves one of the last remaining blockers for #21778. Fixes lld linking shared libs for macos via libtool.

  lld fails one of libtool's earliest checks [because it happens to output a warning that contains a specific string](https://git.savannah.gnu.org/cgit/libtool.git/tree/m4/libtool.m4#n999):

  >     # If there is a non-empty error log, and "single_module"
  >     # appears in it, assume the flag caused a linker warning

  And here is the test being run:
  > x86_64-apple-darwin-ld: warning: Option `-single_module' is deprecated in ld64:
  > x86_64-apple-darwin-ld: warning: Unnecessary option: this is already the default

  Because the warning is printed the test fails. So libtool falls back to a very primitive and broken link-line for shared libs.

  Arguably this should be worked-around in upstream lld by changing the warning string, as otherwise every libtool project will fail to link with it.

  Like many other libtool hacks, the solution is to simply disable the check and hard-code the answer we know to be correct.

ACKs for top commit:
  hebasto:
    re-ACK 67aacc73ea427f89f005ae17d5fd1572409e649e

Tree-SHA512: 792e4d208a3a4921edb5f267f43ecd052b5b650df0db5cb2788ee1e4f3c4087413f354b22e407ff5fa2f99a22a16154ec6826d14c6654a57c00aae3b3e744bca
This commit is contained in:
fanquake 2023-05-14 11:08:37 +01:00 committed by pasta
parent b8ddcd937c
commit 45cc44bcf9
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@ -57,13 +57,24 @@ else
fi
AC_PROG_CXX
dnl By default, libtool for mingw refuses to link static libs into a dll for
dnl fear of mixing pic/non-pic objects, and import/export complications. Since
dnl we have those under control, re-enable that functionality.
dnl libtool overrides
case $host in
*mingw*)
dnl By default, libtool for mingw refuses to link static libs into a dll for
dnl fear of mixing pic/non-pic objects, and import/export complications. Since
dnl we have those under control, re-enable that functionality.
lt_cv_deplibs_check_method="pass_all"
;;
*darwin*)
dnl Because it prints a verbose warning, lld fails the following check
dnl for "-Wl,-single_module" from libtool.m4:
dnl # If there is a non-empty error log, and "single_module"
dnl # appears in it, assume the flag caused a linker warning
dnl "-single_module" works fine on ld64 and lld, so just bypass the test.
dnl Failure to set this to "yes" causes libtool to use a very broken
dnl link-line for shared libs.
lt_cv_apple_cc_single_mod="yes"
;;
esac
AC_ARG_ENABLE([c++20],