Fix OCaml build failure because of absolute path in system libs

[haampie]

Summary

https://reviews.llvm.org/D85820 introduced a full path in the LLVM_SYSTEM_LIBS property of the LLVMSupport target, which made the OCaml bindings fail to build, since they use -l [system_lib] flags for every lib in LLVM_SYSTEM_LIBS, which cannot work with absolute paths.

This patch solves the issue in a similar vain as ZLIB does it: it adds the full library path to imported_libs, and adds a stripped down version without directories, lib prefix and lib suffix to system_libs

In the future we should probably make some changes to LLVM_SYSTEM_LIBS, since both zlib and ncurses do not necessarily have to be system libs anymore due to the find_package / find_library bits introduced in https://reviews.llvm.org/D85820 and https://reviews.llvm.org/D79219.

[phosek]

llvm/lib/Support/CMakeLists.txt

5

We typically use lowercase for function arguments, also the output variable usually goes at the end (unless the function has variable number of arguments).

[haampie]

Move the output variable to the end and use lowercase for arguments.

Change the library name regex to use CMAKE_FIND_LIBRARY_PREFIXES and CMAKE_FIND_LIBRARY_SUFFIXES, since those are used by find_library. This fixes an issue on macOS for zlib introduced in https://reviews.llvm.org/D79219 too, since find_package finds a stub library with a .tbd suffix on darwin by default.

Before this differential on macOS (from BuildVariables.inc):

#define LLVM_SYSTEM_LIBS "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/lib/libcurses.tbd -lm -llibz.tbd -lxml2"

After:

#define LLVM_SYSTEM_LIBS "-lm -lz -lcurses -lxml2"

[phosek]

LGTM

[RKSimon]

@haampie Do we have a confirmation that this works yet? I'm willing to do a test commit before too much of the US wakes up.

[phosek]

@haampie I landed your change but I'm seeing the following failure on sanitizer Windows bot:

CMake Error at lib/Support/CMakeLists.txt:223 (get_system_libname):
  get_system_libname Function invoked with incorrect arguments for function
  named: get_system_libname

The failing build is http://lab.llvm.org:8011/builders/sanitizer-windows/builds/68331

I'm going to revert the change, but I'm happy to reland it once we figure out what the problem is.

[gribozavr2]

@haampie This change helped, thanks!

http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/34742 (red) ->
http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/34743 (green)

[aeubanks]

In D86134#2226701, @phosek wrote:

@haampie I landed your change but I'm seeing the following failure on sanitizer Windows bot:

CMake Error at lib/Support/CMakeLists.txt:223 (get_system_libname):
  get_system_libname Function invoked with incorrect arguments for function
  named: get_system_libname

The failing build is http://lab.llvm.org:8011/builders/sanitizer-windows/builds/68331

I'm going to revert the change, but I'm happy to reland it once we figure out what the problem is.

I also think this broke the Windows builds for Chrome: https://crbug.com/1119478.
CMake Error at lib/Support/CMakeLists.txt:9 (STRING):

STRING sub-command REGEX, mode REPLACE: regex "^()" matched an empty
string.

Call Stack (most recent call first):

lib/Support/CMakeLists.txt:218 (get_system_libname)

Might need zlib to repro.

[phosek]

In D86134#2226975, @aeubanks wrote:

In D86134#2226701, @phosek wrote:

@haampie I landed your change but I'm seeing the following failure on sanitizer Windows bot:

CMake Error at lib/Support/CMakeLists.txt:223 (get_system_libname):
  get_system_libname Function invoked with incorrect arguments for function
  named: get_system_libname

The failing build is http://lab.llvm.org:8011/builders/sanitizer-windows/builds/68331

I'm going to revert the change, but I'm happy to reland it once we figure out what the problem is.

I also think this broke the Windows builds for Chrome: https://crbug.com/1119478.
CMake Error at lib/Support/CMakeLists.txt:9 (STRING):

STRING sub-command REGEX, mode REPLACE: regex "^()" matched an empty
string.

Call Stack (most recent call first):

lib/Support/CMakeLists.txt:218 (get_system_libname)

Might need zlib to repro.

I've addressed the terminfo issue with D86234, I can look into the zlib issue.

llvm/lib/Support/CMakeLists.txt

222

We might need to gate this block on CMAKE_HOST_UNIX just like we do above, but I'm also a bit surprised that LLVM_ENABLE_TERMINFO is TRUE on Windows?

[haampie]

@aeubanks and @phosek: see https://reviews.llvm.org/D86245 for a last fix that checks whether CMAKE_FIND_LIBRARY_PREFIXES and CMAKE_FIND_LIBRARY_SUFFIXES are non-empty before applying the regex to fix this window issue

llvm/lib/Support/CMakeLists.txt

 if(LLVM_ENABLE_ZLIB)
   set(imported_libs ZLIB::ZLIB)
 endif()
 
+function(get_system_libname libpath libname)
+  get_filename_component(libpath ${libpath} NAME)
+  string(REPLACE ";" "|" PREFIXES "${CMAKE_FIND_LIBRARY_PREFIXES}")
+  string(REPLACE ";" "|" SUFFIXES "${CMAKE_FIND_LIBRARY_SUFFIXES}")
+  STRING(REGEX REPLACE "^(${PREFIXES})" "" libpath ${libpath})
+  STRING(REGEX REPLACE "(${SUFFIXES})$" "" libpath ${libpath})
+  set(${libname} "${libpath}" PARENT_SCOPE)
+endfunction()
+
 if( MSVC OR MINGW )
   # libuuid required for FOLDERID_Profile usage in lib/Support/Windows/Path.inc.
   # advapi32 required for CryptAcquireContextW in lib/Support/Windows/Path.inc.
   set(system_libs ${system_libs} psapi shell32 ole32 uuid advapi32)
 elseif( CMAKE_HOST_UNIX )
   if( HAVE_LIBRT )
     set(system_libs ${system_libs} rt)
   endif()
   if( HAVE_LIBDL )
     set(system_libs ${system_libs} ${CMAKE_DL_LIBS})
   endif()
   if( HAVE_BACKTRACE AND NOT "${Backtrace_LIBRARIES}" STREQUAL "" )
     # On BSDs, CMake returns a fully qualified path to the backtrace library.
     # We need to remove the path and the 'lib' prefix, to make it look like a
     # regular short library name, suitable for appending to a -l link flag.
     get_filename_component(Backtrace_LIBFILE ${Backtrace_LIBRARIES} NAME_WE)
     STRING(REGEX REPLACE "^lib" "" Backtrace_LIBFILE ${Backtrace_LIBFILE})
     set(system_libs ${system_libs} ${Backtrace_LIBFILE})
   endif()
   if( LLVM_ENABLE_TERMINFO )
-    set(system_libs ${system_libs} ${TERMINFO_LIB})
+    set(imported_libs ${imported_libs} "${TERMINFO_LIB}")
   endif()
   if( LLVM_ENABLE_THREADS AND (HAVE_LIBATOMIC OR HAVE_CXX_LIBATOMICS64) )
     set(system_libs ${system_libs} atomic)
   endif()
   set(system_libs ${system_libs} ${LLVM_PTHREAD_LIB})
   if( UNIX AND NOT (BEOS OR HAIKU) )
     set(system_libs ${system_libs} m)
   endif()
if(LLVM_ENABLE_ZLIB)
   # CMAKE_BUILD_TYPE is only meaningful to single-configuration generators.
   if(CMAKE_BUILD_TYPE)
     string(TOUPPER ${CMAKE_BUILD_TYPE} build_type)
     get_property(zlib_library TARGET ZLIB::ZLIB PROPERTY LOCATION_${build_type})
   endif()
   if(NOT zlib_library)
     get_property(zlib_library TARGET ZLIB::ZLIB PROPERTY LOCATION)
   endif()
-  get_filename_component(zlib_library ${zlib_library} NAME)
-  if(CMAKE_STATIC_LIBRARY_PREFIX AND CMAKE_STATIC_LIBRARY_SUFFIX AND
-      zlib_library MATCHES "^${CMAKE_STATIC_LIBRARY_PREFIX}.*${CMAKE_STATIC_LIBRARY_SUFFIX}$")
-    STRING(REGEX REPLACE "^${CMAKE_STATIC_LIBRARY_PREFIX}" "" zlib_library ${zlib_library})
-    STRING(REGEX REPLACE "${CMAKE_STATIC_LIBRARY_SUFFIX}$" "" zlib_library ${zlib_library})
-  endif()
-  if(CMAKE_SHARED_LIBRARY_PREFIX AND CMAKE_SHARED_LIBRARY_SUFFIX AND
-      zlib_library MATCHES "^${CMAKE_SHARED_LIBRARY_PREFIX}.*${CMAKE_SHARED_LIBRARY_SUFFIX}$")
-    STRING(REGEX REPLACE "^${CMAKE_SHARED_LIBRARY_PREFIX}" "" zlib_library ${zlib_library})
-    STRING(REGEX REPLACE "${CMAKE_SHARED_LIBRARY_SUFFIX}$" "" zlib_library ${zlib_library})
-  endif()
+  get_system_libname(${zlib_library} zlib_library)
   set(llvm_system_libs ${llvm_system_libs} "${zlib_library}")
 endif()
 
+if(LLVM_ENABLE_TERMINFO)
+  get_system_libname(${TERMINFO_LIB} terminfo_library)
+  set(llvm_system_libs ${llvm_system_libs} "${terminfo_library}")
+endif()
+
 set_property(TARGET LLVMSupport PROPERTY LLVM_SYSTEM_LIBS "${llvm_system_libs}")
 
 if(LLVM_WITH_Z3)
   target_include_directories(LLVMSupport SYSTEM
     PRIVATE
     ${Z3_INCLUDE_DIR}
     )
 endif()