Simplify cmake by having a single binaryen library target (WebAssembly#7238)

Instead of declaring a separate static library target for each
subdirectory, declare a single binaryen library target up front and then
add sources to it from each subdirectory.

Requires updating the minimum cmake version to avoid policy errors.

Author: tlively

CMakeLists.txt

@@ -1,6 +1,6 @@
 # Version set according the the cmake versions available in Ubuntu/Bionic:
-# https://packages.ubuntu.com/bionic/cmake
-cmake_minimum_required(VERSION 3.10.2)
+# https://packages.ubuntu.com/focal/cmake
+cmake_minimum_required(VERSION 3.16.3)
 
 # Needed for C++17 (std::variant)
 # TODO(https://github.com/WebAssembly/binaryen/issues/4299): We need
@@ -172,12 +172,12 @@ if(NOT EMSCRIPTEN)
   endif()
 endif()
 
-# Compiler setup.
+# Compiler setup. Use SYSTEM to avoid warnings and errors from third-party headers.
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/src)
-include_directories(${CMAKE_CURRENT_SOURCE_DIR}/third_party/FP16/include)
+include_directories(SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/third_party/FP16/include)
 if(BUILD_LLVM_DWARF)
-  include_directories(${CMAKE_CURRENT_SOURCE_DIR}/third_party/llvm-project/include)
+  include_directories(SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/third_party/llvm-project/include)
 endif()
 
 # Add output directory to include path so config.h can be found
@@ -400,10 +400,15 @@ if(UNIX AND CMAKE_GENERATOR STREQUAL "Ninja")
   endif()
 endif()
 
-# Static libraries
-# Current (partial) dependency structure is as follows:
-# tools -> passes -> wasm -> asmjs -> support
-# TODO: It's odd that wasm should depend on asmjs, maybe we should fix that.
+if(BUILD_STATIC_LIB)
+  message(STATUS "Building libbinaryen as statically linked library.")
+  add_library(binaryen STATIC)
+  add_definitions(-DBUILD_STATIC_LIBRARY)
+else()
+  message(STATUS "Building libbinaryen as shared library.")
+  add_library(binaryen SHARED)
+endif()
+
 add_subdirectory(src/ir)
 add_subdirectory(src/asmjs)
 add_subdirectory(src/cfg)
@@ -430,39 +435,16 @@ if(BUILD_TESTS)
   add_subdirectory(test/gtest)
 endif()
 
-# Object files
-set(binaryen_objs
-    $<TARGET_OBJECTS:passes>
-    $<TARGET_OBJECTS:wasm>
-    $<TARGET_OBJECTS:asmjs>
-    $<TARGET_OBJECTS:emscripten-optimizer>
-    $<TARGET_OBJECTS:ir>
-    $<TARGET_OBJECTS:cfg>
-    $<TARGET_OBJECTS:support>
-    $<TARGET_OBJECTS:analysis>
-    $<TARGET_OBJECTS:parser>
-    $<TARGET_OBJECTS:interpreter>)
-
-if(BUILD_LLVM_DWARF)
-  SET(binaryen_objs ${binaryen_objs} $<TARGET_OBJECTS:llvm_dwarf>)
-endif()
-
 # Sources.
 
 file(GLOB binaryen_HEADERS src/*.h)
 set(binaryen_SOURCES
   src/binaryen-c.cpp
   ${binaryen_HEADERS}
 )
-if(BUILD_STATIC_LIB)
-  message(STATUS "Building libbinaryen as statically linked library.")
-  add_library(binaryen STATIC ${binaryen_SOURCES} ${binaryen_objs})
-  add_definitions(-DBUILD_STATIC_LIBRARY)
-else()
-  message(STATUS "Building libbinaryen as shared library.")
-  add_library(binaryen SHARED ${binaryen_SOURCES} ${binaryen_objs})
-endif()
+target_sources(binaryen PRIVATE ${binaryen_SOURCES})
 target_link_libraries(binaryen ${CMAKE_THREAD_LIBS_INIT})
+
 if(INSTALL_LIBS OR NOT BUILD_STATIC_LIB)
   install(TARGETS binaryen
     RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
@@ -483,7 +465,7 @@ if(EMSCRIPTEN)
   # binaryen.js WebAssembly variant
   add_executable(binaryen_wasm
                  ${binaryen_SOURCES})
-  target_link_libraries(binaryen_wasm wasm asmjs emscripten-optimizer passes ir cfg support analysis parser interpreter wasm)
+  target_link_libraries(binaryen_wasm binaryen)
   target_link_libraries(binaryen_wasm "-sFILESYSTEM")
   target_link_libraries(binaryen_wasm "-sEXPORT_NAME=Binaryen")
   target_link_libraries(binaryen_wasm "-sNODERAWFS=0")
@@ -513,7 +495,7 @@ if(EMSCRIPTEN)
   # binaryen.js JavaScript variant
   add_executable(binaryen_js
                  ${binaryen_SOURCES})
-  target_link_libraries(binaryen_js wasm asmjs emscripten-optimizer passes ir cfg support analysis parser interpreter wasm)
+  target_link_libraries(binaryen_js binaryen)
   target_link_libraries(binaryen_js "-sWASM=0")
   target_link_libraries(binaryen_js "-sWASM_ASYNC_COMPILATION=0")
   if(${CMAKE_CXX_COMPILER_VERSION} STREQUAL "6.0.1")

src/analysis/CMakeLists.txt

@@ -3,4 +3,4 @@ set(analysis_SOURCES
   cfg.cpp
   ${analysis_HEADERS}
 )
-add_library(analysis OBJECT ${analysis_SOURCES})
+target_sources(binaryen PRIVATE ${analysis_SOURCES})

src/asmjs/CMakeLists.txt

@@ -5,4 +5,4 @@ set(asmjs_SOURCES
   shared-constants.cpp
   ${asmjs_HEADERS}
 )
-add_library(asmjs OBJECT ${asmjs_SOURCES})
+target_sources(binaryen PRIVATE ${asmjs_SOURCES})

src/cfg/CMakeLists.txt

@@ -3,4 +3,4 @@ set(cfg_SOURCES
   Relooper.cpp
   ${cfg_HEADERS}
 )
-add_library(cfg OBJECT ${cfg_SOURCES})
+target_sources(binaryen PRIVATE ${cfg_SOURCES})

src/emscripten-optimizer/CMakeLists.txt

@@ -5,4 +5,4 @@ set(emscripten-optimizer_SOURCES
   simple_ast.cpp
   ${emscripten-optimizer_HEADERS}
 )
-add_library(emscripten-optimizer OBJECT ${emscripten-optimizer_SOURCES})
+target_sources(binaryen PRIVATE ${emscripten-optimizer_SOURCES})

src/interpreter/CMakeLists.txt

@@ -4,4 +4,4 @@ set(interpreter_SOURCES
  interpreter.cpp
  ${interpreter_HEADERS}
 )
-add_library(interpreter OBJECT ${interpreter_SOURCES})
+target_sources(binaryen PRIVATE ${interpreter_SOURCES})

src/ir/CMakeLists.txt

@@ -24,4 +24,4 @@ set(ir_SOURCES
   module-splitting.cpp
   ${ir_HEADERS}
 )
-add_library(ir OBJECT ${ir_SOURCES})
+target_sources(binaryen PRIVATE ${ir_SOURCES})

src/parser/CMakeLists.txt

@@ -12,4 +12,4 @@ set(parser_SOURCES
  wat-parser.cpp
  ${parser_HEADERS}
 )
-add_library(parser OBJECT ${parser_SOURCES})
+target_sources(binaryen PRIVATE ${parser_SOURCES})

src/passes/CMakeLists.txt

@@ -144,4 +144,4 @@ if(EMSCRIPTEN)
   list(REMOVE_ITEM passes_SOURCES "hash-stringify-walker.cpp")
   list(REMOVE_ITEM passes_SOURCES "Outlining.cpp")
 endif()
-add_library(passes OBJECT ${passes_SOURCES})
+target_sources(binaryen PRIVATE ${passes_SOURCES})

src/support/CMakeLists.txt

@@ -22,12 +22,12 @@ set(support_SOURCES
 # suffix_tree_node source files no longer depend on LLVM code in the
 # third_party folder
 if(EMSCRIPTEN)
-  add_library(support OBJECT ${support_SOURCES})
+  target_sources(binaryen PRIVATE ${support_SOURCES})
 else()
   set(support_with_suffix_tree_SOURCES
     suffix_tree.cpp
     suffix_tree_node.cpp
     ${support_SOURCES}
   )
-  add_library(support OBJECT ${support_with_suffix_tree_SOURCES})
+  target_sources(binaryen PRIVATE ${support_with_suffix_tree_SOURCES})
 endif()