Adapt the build system for WASI.

Author: veluca93

clang/CMakeLists.txt

@@ -427,7 +427,7 @@ CMAKE_DEPENDENT_OPTION(CLANG_PLUGIN_SUPPORT
 # If libstdc++ is statically linked, clang-repl needs to statically link libstdc++
 # itself, which is not possible in many platforms because of current limitations in
 # JIT stack. (more platforms need to be supported by JITLink)
-if(NOT LLVM_STATIC_LINK_CXX_STDLIB)
+if(NOT LLVM_STATIC_LINK_CXX_STDLIB AND NOT WASI)
   set(HAVE_CLANG_REPL_SUPPORT ON)
 endif()
 

libcxxabi/src/CMakeLists.txt

@@ -36,8 +36,8 @@ else()
   )
 endif()
 
-if (LIBCXXABI_ENABLE_THREADS AND (UNIX OR FUCHSIA) AND NOT (APPLE OR CYGWIN)
-    AND NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX"))
+if (LIBCXXABI_ENABLE_THREADS AND (UNIX OR FUCHSIA OR WASI) AND NOT
+  (APPLE OR CYGWIN) AND NOT (${CMAKE_SYSTEM_NAME} MATCHES "AIX"))
   list(APPEND LIBCXXABI_SOURCES
     cxa_thread_atexit.cpp
   )

llvm/cmake/modules/HandleLLVMOptions.cmake

@@ -217,6 +217,10 @@ elseif(FUCHSIA OR UNIX)
   else()
     set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)
   endif()
+elseif(WASI)
+  set(LLVM_ON_WIN32 0)
+  set(LLVM_ON_UNIX 1)
+  set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Generic")
   set(LLVM_ON_WIN32 0)
   set(LLVM_ON_UNIX 0)

llvm/lib/CMakeLists.txt

@@ -31,7 +31,9 @@ add_subdirectory(Remarks)
 add_subdirectory(Debuginfod)
 add_subdirectory(DebugInfo)
 add_subdirectory(DWP)
+if (NOT WASI)
 add_subdirectory(ExecutionEngine)
+endif ()
 add_subdirectory(Target)
 add_subdirectory(AsmParser)
 add_subdirectory(LineEditor)

llvm/lib/Transforms/CMakeLists.txt

@@ -5,7 +5,9 @@ add_subdirectory(InstCombine)
 add_subdirectory(Scalar)
 add_subdirectory(IPO)
 add_subdirectory(Vectorize)
+if (NOT WASI)
 add_subdirectory(Hello)
+endif ()
 add_subdirectory(ObjCARC)
 add_subdirectory(Coroutines)
 add_subdirectory(CFGuard)

llvm/tools/CMakeLists.txt

@@ -28,12 +28,14 @@ endif()
 # Add LTO, llvm-ar, llvm-config, and llvm-profdata before clang, ExternalProject
 # requires targets specified in DEPENDS to exist before the call to
 # ExternalProject_Add.
+if (NOT WASI)
 add_llvm_tool_subdirectory(lto)
 add_llvm_tool_subdirectory(gold)
 add_llvm_tool_subdirectory(llvm-ar)
 add_llvm_tool_subdirectory(llvm-config)
 add_llvm_tool_subdirectory(llvm-lto)
 add_llvm_tool_subdirectory(llvm-profdata)
+endif ()
 
 # Projects supported via LLVM_EXTERNAL_*_SOURCE_DIR need to be explicitly
 # specified.
@@ -43,6 +45,7 @@ add_llvm_external_project(mlir)
 # accordingly so place them afterwards
 add_llvm_external_project(clang)
 add_llvm_external_project(flang)
+if (NOT WASI)
 add_llvm_external_project(lldb)
 add_llvm_external_project(bolt)
 
@@ -54,6 +57,7 @@ add_llvm_external_project(polly)
 
 # libclc depends on clang
 add_llvm_external_project(libclc)
+endif ()
 
 # Add subprojects specified using LLVM_EXTERNAL_PROJECTS
 foreach(p ${LLVM_EXTERNAL_PROJECTS})