Allow using mimalloc with dynamic linking (#7391)

With dynamic linking, build and link mimalloc's dynamic library, and  include it
in the installation (this also brings along the headers and CMake files, but it
seemed like more trouble than it was worth to try to manually install just the
library or remove the extras).
The static build remains the same.

Remove the restriction that mimalloc can only be linked into a static-lib build.

Author: dschuff

.github/workflows/ci.yml

@@ -250,7 +250,7 @@ jobs:
 
     - name: cmake
       run: |
-        ./alpine.sh cmake . -G Ninja -DCMAKE_INSTALL_PREFIX=out/install -DCMAKE_CXX_FLAGS="-static" -DCMAKE_C_FLAGS="-static" -DCMAKE_BUILD_TYPE=Release -DBUILD_STATIC_LIB=ON -DMIMALLOC_STATIC=ON -DCMAKE_INSTALL_PREFIX=install
+        ./alpine.sh cmake . -G Ninja -DCMAKE_INSTALL_PREFIX=out/install -DCMAKE_CXX_FLAGS="-static" -DCMAKE_C_FLAGS="-static" -DCMAKE_BUILD_TYPE=Release -DBUILD_STATIC_LIB=ON -DBUILD_MIMALLOC=ON -DCMAKE_INSTALL_PREFIX=install
 
     - name: build
       run: |

.github/workflows/create_release.yml

@@ -140,7 +140,7 @@ jobs:
 
     - name: cmake
       run: |
-        ./alpine.sh cmake . -G Ninja -DCMAKE_CXX_FLAGS="-static" -DCMAKE_C_FLAGS="-static" -DCMAKE_BUILD_TYPE=Release -DBUILD_STATIC_LIB=ON -DMIMALLOC_STATIC=ON -DCMAKE_INSTALL_PREFIX=install
+        ./alpine.sh cmake . -G Ninja -DCMAKE_CXX_FLAGS="-static" -DCMAKE_C_FLAGS="-static" -DCMAKE_BUILD_TYPE=Release -DBUILD_STATIC_LIB=ON -DBUILD_MIMALLOC=ON -DCMAKE_INSTALL_PREFIX=install
 
     - name: build
       run: |

CMakeLists.txt

@@ -56,9 +56,10 @@ endif()
 # Advised to turn on when statically linking against musl libc (e.g., in the
 # Alpine Linux build we use for producing official Linux binaries), because
 # musl libc's allocator has very bad performance on heavily multi-threaded
-# workloads / high core count machines.
+# workloads / high core count machines. But it also works with dynamic linking
+# with a small performance advantage in some cases over the glibc allocator.
 # See https://github.com/WebAssembly/binaryen/issues/5561.
-option(MIMALLOC_STATIC "Build with statically linked mimalloc allocator" OFF)
+option(BUILD_MIMALLOC "Build with mimalloc allocator" OFF)
 
 # Turn this off to install only tools and not static/dynamic libs.
 option(INSTALL_LIBS "Install libraries" ON)
@@ -467,12 +468,16 @@ if(BUILD_LLVM_DWARF)
   target_link_libraries(binaryen llvm_dwarf)
 endif()
 
-if(MIMALLOC_STATIC)
-  if(NOT(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND BUILD_STATIC_LIB) OR EMSCRIPTEN)
-    message(FATAL_ERROR "Statically linking mimalloc is only supported when building as a native, statically linked library on Linux.")
+if(BUILD_MIMALLOC)
+  if(NOT(CMAKE_SYSTEM_NAME STREQUAL "Linux") OR EMSCRIPTEN)
+    message(FATAL_ERROR "Linking mimalloc is only supported on Linux.")
+  endif()
+  message(STATUS "Building with mimalloc allocator.")
+  if(BUILD_STATIC_LIB)
+    target_link_libraries(binaryen mimalloc-static)
+  else()
+    target_link_libraries(binaryen mimalloc)
   endif()
-  message(STATUS "Building with statically linked mimalloc allocator.")
-  target_link_libraries(binaryen mimalloc-static)
 endif()
 
 add_subdirectory(src/ir)

third_party/CMakeLists.txt

@@ -16,15 +16,23 @@ if(BUILD_LLVM_DWARF)
   add_subdirectory(llvm-project)
 endif()
 
-if(MIMALLOC_STATIC)
-  # We only need the static library, nothing else.
-  set(MI_BUILD_STATIC ON)
-  set(MI_BUILD_SHARED OFF)
+if(BUILD_MIMALLOC)
+  # Match static/dynamic linking between libbinaryen and mimalloc
+  set(MI_BUILD_STATIC ${BUILD_STATIC_LIB})
+  if (BUILD_STATIC_LIB)
+    set(MI_BUILD_SHARED OFF)
+  endif()
   set(MI_BUILD_OBJECT OFF)
   set(MI_BUILD_TESTS OFF)
+  set(MI_INSTALL_TOPLEVEL ON)
   # Do not show debug and warning messages of the allocator by default.
   # (They can still be enabled via MIMALLOC_VERBOSE=1 wasm-opt ...)
   add_compile_definitions(MI_DEBUG=0)
 
-  add_subdirectory(mimalloc EXCLUDE_FROM_ALL)
+  if(BUILD_STATIC_LIB)
+    # No need to install libmimalloc.a when it's linked statically into the tools.
+    add_subdirectory(mimalloc EXCLUDE_FROM_ALL)
+  else()
+    add_subdirectory(mimalloc)
+  endif()
 endif()