Merge pull request #5308 from halide/build/shared-llvm-fix

Fix linking to shared LLVM.
halide · Oct 18, 2020 · c7622e4 · c7622e4
1 parent b7d96d4
commit c7622e4
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Showing 3 changed files with 41 additions and 33 deletions.
diff --git a/cmake/BundleStatic.cmake b/cmake/BundleStatic.cmake
@@ -33,16 +33,15 @@ cmake_minimum_required(VERSION 3.16)
 # IMPORTED_NO_SONAME(_<CONFIG>) # shared-only
 # IMPORTED_SONAME(_<CONFIG>) # shared-only
 
-function(bundle_static)
+function(bundle_static TARGET)
     set(options)
-    set(oneValueArgs TARGET)
+    set(oneValueArgs)
     set(multiValueArgs LIBRARIES)
     cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
 
-    set(interfaceLib ${ARG_TARGET})
-    set(objectLib ${ARG_TARGET}.obj)
+    set(interfaceLib ${TARGET})
+    set(objectLib ${interfaceLib}.obj)
 
-    add_library(${interfaceLib} INTERFACE)
     add_library(${objectLib} OBJECT IMPORTED)
     set_target_properties(${objectLib} PROPERTIES IMPORTED_GLOBAL TRUE)
 

diff --git a/dependencies/llvm/CMakeLists.txt b/dependencies/llvm/CMakeLists.txt
@@ -3,13 +3,14 @@
 ##
 
 include(CMakeDependentOption)
+include(BundleStatic)
 
 # Fallback configurations for weirdly built LLVMs
 set(CMAKE_MAP_IMPORTED_CONFIG_MINSIZEREL MinSizeRel Release RelWithDebInfo "")
 set(CMAKE_MAP_IMPORTED_CONFIG_RELWITHDEBINFO RelWithDebInfo Release MinSizeRel "")
 set(CMAKE_MAP_IMPORTED_CONFIG_RELEASE Release MinSizeRel RelWithDebInfo "")
 
-find_package(LLVM ${HALIDE_REQUIRE_LLVM_VERSION} REQUIRED)
+find_package(LLVM ${Halide_REQUIRE_LLVM_VERSION} REQUIRED)
 find_package(Clang REQUIRED CONFIG HINTS "${LLVM_DIR}/../clang")
 
 message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
@@ -25,6 +26,14 @@ endif ()
 
 set(Halide_LLVM_DEFS ${LLVM_DEFINITIONS} $<BUILD_INTERFACE:LLVM_VERSION=${LLVM_VERSION_MAJOR}${LLVM_VERSION_MINOR}>)
 
+##
+# Options for which version of LLVM to use
+##
+
+option(Halide_SHARED_LLVM "Link against shared LLVM (ignores components)." OFF)
+cmake_dependent_option(Halide_BUNDLE_LLVM "When built as a static library, include LLVM's objects." OFF
+                       "NOT BUILD_SHARED_LIBS" OFF)
+
 ##
 # Promote LLVM/Clang executable targets
 ##
@@ -40,7 +49,7 @@ endif ()
 # Create options for including or excluding LLVM backends.
 ##
 
-set(LLVM_COMPONENTS mcjit bitwriter linker passes)
+set(active_components mcjit bitwriter linker passes)
 set(known_components AArch64 AMDGPU ARM Hexagon Mips NVPTX PowerPC RISCV WebAssembly X86)
 
 # We don't support LLVM10 or below for wasm codegen.
@@ -54,48 +63,48 @@ foreach (comp IN LISTS known_components)
 
     cmake_dependent_option(${OPTION} "Include ${comp} target" ON
                            "${comp} IN_LIST LLVM_TARGETS_TO_BUILD" OFF)
-    if (${OPTION})
+    if (${OPTION} OR Halide_SHARED_LLVM)
         message(STATUS "Enabling ${comp} backend")
         list(APPEND Halide_LLVM_DEFS $<BUILD_INTERFACE:${DEFINE}>)
-        list(APPEND LLVM_COMPONENTS ${comp})
+        list(APPEND active_components ${comp})
     else ()
         message(STATUS "Disabling ${comp} backend")
     endif ()
 endforeach ()
 
+set(wasm_libs "")
+if (TARGET_WEBASSEMBLY)
+    find_package(LLD CONFIG REQUIRED HINTS "${LLVM_DIR}/../lld")
+    set(wasm_libs lldWasm)
+endif ()
+
 ##
 # Create Halide::LLVM library alias pointing to the correct LLVM
 # among shared, static, and bundled.
 ##
 
-option(Halide_BUNDLE_LLVM "When built as a static library, include LLVM's objects." OFF)
-option(Halide_SHARED_LLVM "Link against shared LLVM (disables components)." OFF)
-
-llvm_map_components_to_libnames(LLVM_LIBNAMES ${LLVM_COMPONENTS})
-if (TARGET_WEBASSEMBLY)
-    find_package(LLD CONFIG REQUIRED HINTS "${LLVM_DIR}/../lld")
-    list(APPEND LLVM_LIBNAMES lldWasm)
-endif ()
-
-if (Halide_BUNDLE_LLVM AND NOT BUILD_SHARED_LIBS)
-    include(BundleStatic)
-    bundle_static(LIBRARIES ${LLVM_LIBNAMES} TARGET Halide_LLVM)
-else ()
-    add_library(Halide_LLVM INTERFACE)
-    if (Halide_SHARED_LLVM)
-        set(LLVM_LIBNAMES LLVM)
-        target_link_libraries(Halide_LLVM INTERFACE ${CMAKE_DL_LIBS})
-    endif ()
-    target_link_libraries(Halide_LLVM INTERFACE ${LLVM_LIBNAMES})
-    set_target_properties(${LLVM_LIBNAMES} PROPERTIES IMPORTED_GLOBAL TRUE)
-endif ()
+add_library(Halide_LLVM INTERFACE)
+add_library(Halide::LLVM ALIAS Halide_LLVM)
 
-# Attach the include dirs and (patched) definitions to the target, where they belong.
 set_target_properties(Halide_LLVM PROPERTIES EXPORT_NAME LLVM)
 target_include_directories(Halide_LLVM INTERFACE $<BUILD_INTERFACE:${LLVM_INCLUDE_DIRS}>)
 target_compile_definitions(Halide_LLVM INTERFACE ${Halide_LLVM_DEFS})
 
-add_library(Halide::LLVM ALIAS Halide_LLVM)
+# Link LLVM libraries to Halide_LLVM, depending on shared, static, or bundled selection.
+if (Halide_SHARED_LLVM)
+    # llvm_map_components_to_libnames is not safe to call if the LLVM static libraries
+    # aren't in the package. This happens on Gentoo Linux at least, but might also happen
+    # with custom LLVM build configurations.
+    target_link_libraries(Halide_LLVM INTERFACE LLVM ${wasm_libs} ${CMAKE_DL_LIBS})
+else ()
+    llvm_map_components_to_libnames(llvm_targets ${active_components})
+    list(APPEND llvm_targets ${wasm_libs})
+    if (Halide_BUNDLE_LLVM)
+        bundle_static(Halide_LLVM LIBRARIES ${llvm_targets})
+    else ()
+        target_link_libraries(Halide_LLVM INTERFACE ${llvm_targets})
+    endif ()
+endif ()
 
 ##
 # Language options interface library

diff --git a/src/Generator.cpp b/src/Generator.cpp
@@ -747,7 +747,7 @@ std::string halide_type_to_c_type(const Type &t) {
 
 int generate_filter_main_inner(int argc, char **argv, std::ostream &cerr) {
     const char kUsage[] =
-        "gengen \n"
+        "gengen\n"
         "  [-g GENERATOR_NAME] [-f FUNCTION_NAME] [-o OUTPUT_DIR] [-r RUNTIME_NAME] [-d 1|0]\n"
         "  [-e EMIT_OPTIONS] [-n FILE_BASE_NAME] [-p PLUGIN_NAME] [-s AUTOSCHEDULER_NAME]\n"
         "       target=target-string[,target-string...] [generator_arg=value [...]]\n"