Document these variables.
Change our convention for setting these variables from:
set(CMAKE_EXE_LINKER_FLAGS_INIT "...")
to
string(APPEND CMAKE_EXE_LINKER_FLAGS_INIT " ...")
so that any value previously set by a toolchain file will be used.
The CMAKE_SHARED_LIBRARY_LINK_<LANG>_FLAGS setting has always been meant
for flags needed to export symbols from executables for use by shared
library plugins. Since commit v3.4.0-rc1~58^2~1 (CMP0065: Restrict the
use of CMAKE_SHARED_LIBRARY_LINK_<LANG>_FLAGS, 2015-08-24) this is made
explicit by using the flags only for executables with ENABLE_EXPORTS,
guarded by CMP0065 for compatibility.
On some platforms we were accidentally using this setting to pass other
flags to the linker:
* AIX: -bnoipath, -brtl
* HP-UX: +s, +nodefaultrpath
These flags are incorrectly dropped when CMP0065 is set to NEW. Fix
this by moving the flags to more appropriate places for linking
executables.
The flag was added incorrectly by commit 9c3a6eb4 (Need -brtl when creating
shared libraries, 2003-05-16). According to "man ld" the -G option implies
"-brtl -bnortllib ...", -brtl implies "-brtllib", and -brtllib should only be
used for executables, not shared libraries. Therefore it is incorrect and
unnecessary to specify -brtl explicitly after -G.
Reported-by: Kevin Burge <kcburge@gmail.com>
Move RPATH flags out of Platform/AIX.cmake into platform-specific
compiler information files Platform/AIX-XL and Platform/AIX-GNU.
The flags need to be set for each compiler of each language.
Brad King
Marc Chevrier