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| author | Daniel Scharrer <daniel@constexpr.org> | 2022-09-05 21:42:28 (GMT) |
|---|---|---|
| committer | Brad King <brad.king@kitware.com> | 2022-09-06 15:05:23 (GMT) |
| commit | 67b6f1a09b3e14373ba5683d11300a145c80877f (patch) | |
| tree | 805159e90132a0c42d9411819ee3871af5f4742d /Modules | |
| parent | 6dd6f911178e7daface0b8c3be4b70f920dd8d40 (diff) | |
| download | CMake-67b6f1a09b3e14373ba5683d11300a145c80877f.zip CMake-67b6f1a09b3e14373ba5683d11300a145c80877f.tar.gz CMake-67b6f1a09b3e14373ba5683d11300a145c80877f.tar.bz2 | |
FindZLIB: fix CMAKE_FIND_LIBRARY_PREFIXES being unset when it was empty
CMAKE_FIND_LIBRARY_PREFIXES and CMAKE_FIND_LIBRARY_SUFFIXES have
different behavior when undefined and when defined but empty:
Empty means to use an empty prefix/suffix while undefined means to
use a hardcoded default for the platform we are running on.
Unfortunately, set(a ${b}) will undefine a when b is empty,
meaning that when targeting a platform where either of these variables
is empty (e.g. Windows where CMAKE_FIND_LIBRARY_PREFIXES is empty)
the unpatched FindZLIB code ends up unsetting that variable, causing
all subsequent find_library calls to use the hardcoded default
for the runtime platform (e.g. "lib" for CMAKE_FIND_LIBRARY_PREFIXES
on Linux).
On the other hand, set(a "${b}") will always define a to be empty but
defined so we have to do this dance to fully preserve the state of these
variables.
Diffstat (limited to 'Modules')
| -rw-r--r-- | Modules/FindZLIB.cmake | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/Modules/FindZLIB.cmake b/Modules/FindZLIB.cmake index f50116f..be5c775 100644 --- a/Modules/FindZLIB.cmake +++ b/Modules/FindZLIB.cmake @@ -92,8 +92,16 @@ endforeach() # Allow ZLIB_LIBRARY to be set manually, as the location of the zlib library if(NOT ZLIB_LIBRARY) - set(_zlib_ORIG_CMAKE_FIND_LIBRARY_PREFIXES ${CMAKE_FIND_LIBRARY_PREFIXES}) - set(_zlib_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES}) + if(DEFINED CMAKE_FIND_LIBRARY_PREFIXES) + set(_zlib_ORIG_CMAKE_FIND_LIBRARY_PREFIXES "${CMAKE_FIND_LIBRARY_PREFIXES}") + else() + set(_zlib_ORIG_CMAKE_FIND_LIBRARY_PREFIXES) + endif() + if(DEFINED CMAKE_FIND_LIBRARY_SUFFIXES) + set(_zlib_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES "${CMAKE_FIND_LIBRARY_SUFFIXES}") + else() + set(_zlib_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES) + endif() # Prefix/suffix of the win32/Makefile.gcc build if(WIN32) list(APPEND CMAKE_FIND_LIBRARY_PREFIXES "" "lib") @@ -114,8 +122,16 @@ if(NOT ZLIB_LIBRARY) endforeach() # Restore the original find library ordering - set(CMAKE_FIND_LIBRARY_SUFFIXES ${_zlib_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES}) - set(CMAKE_FIND_LIBRARY_PREFIXES ${_zlib_ORIG_CMAKE_FIND_LIBRARY_PREFIXES}) + if(DEFINED _zlib_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES) + set(CMAKE_FIND_LIBRARY_SUFFIXES "${_zlib_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES}") + else() + set(CMAKE_FIND_LIBRARY_SUFFIXES) + endif() + if(DEFINED _zlib_ORIG_CMAKE_FIND_LIBRARY_PREFIXES) + set(CMAKE_FIND_LIBRARY_PREFIXES "${_zlib_ORIG_CMAKE_FIND_LIBRARY_PREFIXES}") + else() + set(CMAKE_FIND_LIBRARY_PREFIXES) + endif() include(${CMAKE_CURRENT_LIST_DIR}/SelectLibraryConfigurations.cmake) select_library_configurations(ZLIB) |