[CMake] Fix bug in `add_weak_symbols()` function.

Previously the the `weak_symbols.txt` files could be modified and the
build system wouldn't update the link flags automatically. Instead the
developer had to know to reconfigure CMake manually.

This is now fixed by telling CMake that the file being used to
read weak symbols from is a configure-time dependency.

Differential Revision: https://reviews.llvm.org/D50059

llvm-svn: 339559
This commit is contained in:
Dan Liew 2018-08-13 12:59:38 +00:00
parent 74e0f40d98
commit 706005486f
1 changed files with 9 additions and 1 deletions

View File

@ -51,7 +51,15 @@ endmacro()
# This function is only used on Darwin, where undefined symbols must be specified
# in the linker invocation.
function(add_weak_symbols libname link_flags)
file(STRINGS "${COMPILER_RT_SOURCE_DIR}/lib/${libname}/weak_symbols.txt" WEAK_SYMBOLS)
set(weak_symbols_file "${COMPILER_RT_SOURCE_DIR}/lib/${libname}/weak_symbols.txt")
file(STRINGS "${weak_symbols_file}" WEAK_SYMBOLS)
# Add this file as a configure-time dependency so that changes to this
# file trigger a re-configure. This is necessary so that `${link_flags}`
# is changed when appropriate.
set_property(
DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
APPEND
PROPERTY CMAKE_CONFIGURE_DEPENDS "${weak_symbols_file}")
set(local_link_flags ${${link_flags}})
foreach(SYMBOL ${WEAK_SYMBOLS})
set(local_link_flags ${local_link_flags} -Wl,-U,${SYMBOL})