[mlir] Add support for MLIR_LINK_MLIR_DYLIB (#119408)

While MLIR currently supports building a libMLIR.so, it does not support
actually linking against it for its own tools. When building with LTO,
this means we have to relink the world for every tool, and the resulting
binaries are large.

This adds basic support for MLIR_LINK_MLIR_DYLIB, modelled after how
CLANG_LINK_CLANG_DYLIB is implemented: Libraries that are part of
libMLIR.so should be added via mlir_target_link_libraries instead of
target_link_libraries. This will replace them with libMLIR.so if
MLIR_LINK_MLIR_DYLIB is enabled.

This adds basic support, I think there are two more things that can be
done here:
* C API unit tests should link against libMLIR-C.so. Currently these
   still link statically.
* Linking the test libs (not part of libMLIR.so) still pulls in
   dependencies statically that should come from libMLIR.so.

Author: nikic

mlir/CMakeLists.txt

@@ -153,6 +153,9 @@ set(MLIR_INSTALL_AGGREGATE_OBJECTS 1 CACHE BOOL
 
 set(MLIR_BUILD_MLIR_C_DYLIB 0 CACHE BOOL "Builds libMLIR-C shared library.")
 
+set(MLIR_LINK_MLIR_DYLIB ${LLVM_LINK_LLVM_DYLIB} CACHE BOOL
+    "Link tools against libMLIR.so")
+
 configure_file(
   ${MLIR_MAIN_INCLUDE_DIR}/mlir/Config/mlir-config.h.cmake
   ${MLIR_INCLUDE_DIR}/mlir/Config/mlir-config.h)

mlir/cmake/modules/AddMLIR.cmake

@@ -717,3 +717,23 @@ function(mlir_check_all_link_libraries name)
     endforeach()
   endif()
 endfunction(mlir_check_all_link_libraries)
+
+# Link target against a list of MLIR libraries. If MLIR_LINK_MLIR_DYLIB is
+# enabled, this will link against the MLIR dylib instead of the static
+# libraries.
+#
+# This function should be used instead of target_link_libraries() when linking
+# MLIR libraries that are part of the MLIR dylib. For libraries that are not
+# part of the dylib (like test libraries), target_link_libraries() should be
+# used.
+function(mlir_target_link_libraries target type)
+  if (TARGET obj.${target})
+    target_link_libraries(obj.${target} ${ARGN})
+  endif()
+
+  if (MLIR_LINK_MLIR_DYLIB)
+    target_link_libraries(${target} ${type} MLIR)
+  else()
+    target_link_libraries(${target} ${type} ${ARGN})
+  endif()
+endfunction()

mlir/tools/mlir-cpu-runner/CMakeLists.txt

@@ -11,16 +11,18 @@ add_mlir_tool(mlir-cpu-runner
   EXPORT_SYMBOLS
   )
 llvm_update_compile_flags(mlir-cpu-runner)
-target_link_libraries(mlir-cpu-runner PRIVATE
+mlir_target_link_libraries(mlir-cpu-runner PRIVATE
   MLIRAnalysis
   MLIRBuiltinToLLVMIRTranslation
-  MLIRExecutionEngine
   MLIRIR
-  MLIRJitRunner
   MLIRLLVMDialect
   MLIRLLVMToLLVMIRTranslation
   MLIRToLLVMIRTranslationRegistration
   MLIRParser
   MLIRTargetLLVMIRExport
   MLIRSupport
   )
+target_link_libraries(mlir-cpu-runner PRIVATE
+  MLIRExecutionEngine
+  MLIRJitRunner
+  )

mlir/tools/mlir-lsp-server/CMakeLists.txt

@@ -38,7 +38,6 @@ set(LIBS
   ${conversion_libs}
   ${dialect_libs}
   ${extension_libs}
-  ${test_libs}
 
   MLIRAffineAnalysis
   MLIRAnalysis
@@ -56,11 +55,9 @@ set(LIBS
 
 add_mlir_tool(mlir-lsp-server
   mlir-lsp-server.cpp
-
-  DEPENDS
-  ${LIBS}
   )
-target_link_libraries(mlir-lsp-server PRIVATE ${LIBS})
+mlir_target_link_libraries(mlir-lsp-server PRIVATE ${LIBS})
+target_link_libraries(mlir-lsp-server PRIVATE ${test_libs})
 llvm_update_compile_flags(mlir-lsp-server)
 
 mlir_check_all_link_libraries(mlir-lsp-server)

mlir/tools/mlir-opt/CMakeLists.txt

@@ -45,6 +45,7 @@ if(MLIR_INCLUDE_TESTS)
     MLIRTestReducer
     MLIRTestTransforms
     MLIRTilingInterfaceTestPasses
+    MLIRTosaTestPasses
     MLIRVectorTestPasses
     MLIRTestVectorToSPIRV
     MLIRLLVMTestPasses
@@ -66,7 +67,6 @@ set(LIBS
   ${dialect_libs}
   ${conversion_libs}
   ${extension_libs}
-  ${test_libs}
 
   MLIRAffineAnalysis
   MLIRAnalysis
@@ -99,11 +99,10 @@ add_mlir_library(MLIRMlirOptMain
 add_mlir_tool(mlir-opt
   mlir-opt.cpp
 
-  DEPENDS
-  ${LIBS}
   SUPPORT_PLUGINS
   )
-target_link_libraries(mlir-opt PRIVATE ${LIBS})
+mlir_target_link_libraries(mlir-opt PRIVATE ${LIBS})
+target_link_libraries(mlir-opt PRIVATE ${test_libs})
 llvm_update_compile_flags(mlir-opt)
 
 mlir_check_all_link_libraries(mlir-opt)

mlir/tools/mlir-parser-fuzzer/bytecode/CMakeLists.txt

@@ -6,7 +6,7 @@ add_llvm_fuzzer(mlir-bytecode-parser-fuzzer
   mlir-bytecode-parser-fuzzer.cpp
   DUMMY_MAIN DummyParserFuzzer.cpp
 )
-target_link_libraries(mlir-bytecode-parser-fuzzer
+mlir_target_link_libraries(mlir-bytecode-parser-fuzzer
   PUBLIC
   MLIRIR
   MLIRParser

mlir/tools/mlir-parser-fuzzer/text/CMakeLists.txt

@@ -6,7 +6,7 @@ add_llvm_fuzzer(mlir-text-parser-fuzzer
   mlir-text-parser-fuzzer.cpp
   DUMMY_MAIN DummyParserFuzzer.cpp
 )
-target_link_libraries(mlir-text-parser-fuzzer
+mlir_target_link_libraries(mlir-text-parser-fuzzer
   PUBLIC
   MLIRIR
   MLIRParser

mlir/tools/mlir-query/CMakeLists.txt

@@ -10,11 +10,11 @@ add_mlir_tool(mlir-query
   mlir-query.cpp
   )
 llvm_update_compile_flags(mlir-query)
-target_link_libraries(mlir-query
+mlir_target_link_libraries(mlir-query
   PRIVATE
   ${dialect_libs}
-  ${test_libs}
   MLIRQueryLib
   )
+target_link_libraries(mlir-query PRIVATE ${test_libs})
 
 mlir_check_link_libraries(mlir-query)

mlir/tools/mlir-reduce/CMakeLists.txt

@@ -10,7 +10,6 @@ endif()
 set(LIBS
   ${conversion_libs}
   ${dialect_libs}
-  ${test_libs}
   MLIRDialect
   MLIRIR
   MLIRPass
@@ -19,12 +18,10 @@ set(LIBS
 
 add_mlir_tool(mlir-reduce
   mlir-reduce.cpp
-
-  DEPENDS
-  ${LIBS}
   )
 
-target_link_libraries(mlir-reduce PRIVATE ${LIBS})
+mlir_target_link_libraries(mlir-reduce PRIVATE ${LIBS})
+target_link_libraries(mlir-reduce PRIVATE ${test_libs})
 llvm_update_compile_flags(mlir-reduce)
 
 mlir_check_all_link_libraries(mlir-reduce)

mlir/tools/mlir-rewrite/CMakeLists.txt

@@ -5,7 +5,6 @@ set(LLVM_LINK_COMPONENTS
 
 set(LIBS
   ${dialect_libs}
-  ${test_libs}
 
   MLIRAffineAnalysis
   MLIRAnalysis
@@ -24,11 +23,9 @@ include_directories(../../../clang/include)
 add_mlir_tool(mlir-rewrite
   mlir-rewrite.cpp
 
-  DEPENDS
-  ${LIBS}
   SUPPORT_PLUGINS
   )
-target_link_libraries(mlir-rewrite PRIVATE ${LIBS})
+mlir_target_link_libraries(mlir-rewrite PRIVATE ${LIBS})
 llvm_update_compile_flags(mlir-rewrite)
 
 mlir_check_all_link_libraries(mlir-rewrite)