[CMake] Support LLVM-16 static linking

LLVM static linking in TVM relies on default flags provided by llvm-config, which however does not depend on modern CMake features, namely, imported targets, leading to a series of issues on builds particularly on macOS and Windows. This PR strengthens CMake configuration process to avoid such behavior.
apache · Jun 30, 2023 · c5bec87 · c5bec87
1 parent 28aead9
commit c5bec87
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Showing 2 changed files with 27 additions and 6 deletions.
diff --git a/cmake/utils/FindLLVM.cmake b/cmake/utils/FindLLVM.cmake
@@ -110,6 +110,7 @@ macro(find_llvm use_llvm)
     if(NOT "${__llvm_exit_code}" STREQUAL "0")
       message(FATAL_ERROR "Fatal error executing: ${LLVM_CONFIG} --libdir")
     endif()
+    message(STATUS "LLVM libdir: ${__llvm_libdir}")
     # map prefix => $
     # to handle the case when the prefix contains space.
     string(REPLACE ${__llvm_prefix} "$" __llvm_cxxflags ${__llvm_cxxflags_space})
@@ -144,14 +145,33 @@ macro(find_llvm use_llvm)
     endforeach()
     separate_arguments(__llvm_system_libs)
     foreach(__flag IN ITEMS ${__llvm_system_libs})
-      # If the library file ends in .lib try to
-      # also search the llvm_libdir
-      if(__flag MATCHES ".lib$")
-        if(EXISTS "${__llvm_libdir}/${__flag}")
-          set(__flag "${__llvm_libdir}/${__flag}")
+      if("${__flag}" STREQUAL "-lm")
+        message(STATUS "LLVM links against math")
+        list(APPEND LLVM_LIBS "m")
+      elseif(("${__flag}" STREQUAL "-lz") OR ("${__flag}" STREQUAL "z.lib"))
+        message(STATUS "LLVM links against zlib")
+        find_package(ZLIB REQUIRED)
+        list(APPEND LLVM_LIBS "ZLIB::ZLIB")
+      elseif("${__flag}" STREQUAL "-lzstd" OR ("${__flag}" STREQUAL "zstd.dll.lib"))
+        find_package(zstd REQUIRED)
+        if (TARGET "zstd::libzstd_static")
+          message(STATUS "LLVM links against static zstd")
+          list(APPEND LLVM_LIBS "zstd::libzstd_static")
+        else()
+          message(STATUS "LLVM links against shared zstd")
+          list(APPEND LLVM_LIBS "zstd::libzstd_shared")
         endif()
+      elseif("${__flag}" STREQUAL "-lxml2")
+        message(STATUS "LLVM links against xml2")
+        list(APPEND LLVM_LIBS "-lxml2")
+      elseif((__flag MATCHES ".lib$") AND (EXISTS "${__llvm_libdir}/${__flag}"))
+        # If the library file ends in .lib try to also search the llvm_libdir
+        message(STATUS "LLVM linker flag under LLVM libdir: ${__llvm_libdir}/${__flag}")
+        list(APPEND LLVM_LIBS "${__llvm_libdir}/${__flag}")
+      else()
+        message(STATUS "LLVM linker flag: ${__flag}")
+        list(APPEND LLVM_LIBS "${__flag}")
       endif()
-      list(APPEND LLVM_LIBS "${__flag}")
     endforeach()
   endif()
   message(STATUS "Found LLVM_INCLUDE_DIRS=" "${LLVM_INCLUDE_DIRS}")

diff --git a/tests/scripts/task_config_build_minimal_cross_isa.sh b/tests/scripts/task_config_build_minimal_cross_isa.sh
@@ -44,6 +44,7 @@ if [ "$architecture_type" != "aarch64" ]; then
   echo set\(CMAKE_FIND_ROOT_PATH /usr/aarch64-linux-gnu\) >> config.cmake
   echo set\(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER\) >> config.cmake
   echo set\(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY\) >> config.cmake
+  echo set\(ZLIB_LIBRARY /lib/aarch64-linux-gnu/libz.a\) >> config.cmake
 else
   # This usually runs in the ci_arm docker image.
   echo -e 'find_program(LLVM_CONFIG "llvm-config")\nif (LLVM_CONFIG) \n\tset(USE_LLVM llvm-config) \nelse() \n\tset(USE_LLVM llvm-config-15)\nendif()' >> config.cmake