Create a separate sysroot for coop threads

cmake/wasi-sdk-sysroot.cmake

@@ -21,8 +21,10 @@ message(STATUS "Found executable for `ar`: ${CMAKE_AR}")
 find_program(MAKE make REQUIRED)
 
 set(EXCEPTIONS_DEFAULT "OFF")
+set(COOP_THREADS_POSSIBLE OFF)
 if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 23.0.0)
   set(EXCEPTIONS_DEFAULT "DUAL")
+  set(COOP_THREADS_POSSIBLE ON)
 endif()
 
 option(WASI_SDK_DEBUG_PREFIX_MAP "Pass `-fdebug-prefix-map` for built artifacts" ON)
@@ -45,6 +47,7 @@ endif()
 
 set(wasi_tmp_install ${CMAKE_CURRENT_BINARY_DIR}/install)
 set(wasi_sysroot ${wasi_tmp_install}/share/wasi-sysroot)
+set(coop_threads_sysroot ${wasi_sysroot}/experimental-coop-threads)
 set(wasi_resource_dir ${wasi_tmp_install}/wasi-resource-dir)
 
 if(WASI_SDK_DEBUG_PREFIX_MAP)
@@ -64,7 +67,6 @@ set(default_cmake_args
   -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
   -DCMAKE_C_COMPILER_WORKS=ON
   -DCMAKE_CXX_COMPILER_WORKS=ON
-  -DCMAKE_SYSROOT=${wasi_sysroot}
   -DCMAKE_MODULE_PATH=${CMAKE_CURRENT_SOURCE_DIR}/cmake
   # CMake detects this based on `CMAKE_C_COMPILER` alone and when that compiler
   # is just a bare "clang" installation then it can mistakenly deduce that this
@@ -109,6 +111,7 @@ function(define_compiler_rt target)
         -DCMAKE_CXX_FLAGS=${WASI_SDK_CPU_CFLAGS}
         -DCMAKE_ASM_FLAGS=${WASI_SDK_CPU_CFLAGS}
         -DCMAKE_INSTALL_PREFIX=${wasi_resource_dir}
+        -DCMAKE_SYSROOT=${wasi_sysroot}
     EXCLUDE_FROM_ALL ON
     USES_TERMINAL_CONFIGURE ON
     USES_TERMINAL_BUILD ON
@@ -165,7 +168,7 @@ add_custom_target(compiler-rt DEPENDS compiler-rt-build compiler-rt-post-build)
 # wasi-libc build logic
 # =============================================================================
 
-function(define_wasi_libc_sub target target_suffix lto)
+function(define_wasi_libc_sub sysroot target target_suffix lto)
   string(TOUPPER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE_UPPER)
   get_property(directory_cflags DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY COMPILE_OPTIONS)
   set(extra_cflags_list "${WASI_SDK_CPU_CFLAGS} ${CMAKE_C_FLAGS} ${directory_cflags}")
@@ -205,34 +208,45 @@ function(define_wasi_libc_sub target target_suffix lto)
     list(APPEND extra_cmake_args -DBUILD_SHARED=OFF)
   endif()
 
+  if (${sysroot} STREQUAL ${coop_threads_sysroot})
+    list(APPEND extra_cmake_args -DENABLE_COOP_THREADS=ON)
+  endif()
+
   ExternalProject_Add(wasi-libc-${target}${target_suffix}-build
     SOURCE_DIR ${wasi_libc}
     CMAKE_ARGS
       ${default_cmake_args}
       ${extra_cmake_args}
       -DTARGET_TRIPLE=${target}
-      -DCMAKE_INSTALL_PREFIX=${wasi_sysroot}
+      -DCMAKE_INSTALL_PREFIX=${sysroot}
       -DCMAKE_C_FLAGS=${extra_cflags}
       -DCMAKE_ASM_FLAGS=${extra_cflags}
       -DBUILTINS_LIB=${libcompiler_rt_a}
       -DUSE_WASM_COMPONENT_LD=OFF
       -DWASI_SDK_VERSION=${wasi_sdk_version}
+      -DCMAKE_SYSROOT=${sysroot}
     DEPENDS compiler-rt
     EXCLUDE_FROM_ALL ON
     USES_TERMINAL_CONFIGURE ON
     USES_TERMINAL_BUILD ON
     USES_TERMINAL_INSTALL ON
   )
+
+  add_dependencies(wasi-libc-${target} wasi-libc-${target}${target_suffix}-build)
 endfunction()
 
 function(define_wasi_libc target)
-  define_wasi_libc_sub (${target} "" OFF)
+  add_custom_target(wasi-libc-${target})
+  define_wasi_libc_sub(${wasi_sysroot} ${target} "" OFF)
   if(WASI_SDK_LTO)
-    define_wasi_libc_sub (${target} "-lto" ON)
+    define_wasi_libc_sub(${wasi_sysroot} ${target} "-lto" ON)
   endif()
 
-  add_custom_target(wasi-libc-${target}
-    DEPENDS wasi-libc-${target}-build $<$<BOOL:${WASI_SDK_LTO}>:wasi-libc-${target}-lto-build>)
+  # Temporary wasip3 experimental coop threads sysroot before it's enabled by
+  # default.
+  if (${target} STREQUAL wasm32-wasip3 AND ${COOP_THREADS_POSSIBLE})
+    define_wasi_libc_sub(${coop_threads_sysroot} ${target} "-coop" OFF)
+  endif()
 endfunction()
 
 foreach(target IN LISTS WASI_SDK_TARGETS)
@@ -248,7 +262,7 @@ execute_process(
   OUTPUT_VARIABLE llvm_version
   OUTPUT_STRIP_TRAILING_WHITESPACE)
 
-function(define_libcxx_sub target target_suffix extra_target_flags extra_libdir_suffix exceptions)
+function(define_libcxx_sub sysroot target target_suffix extra_target_flags extra_libdir_suffix exceptions)
   if(${target} MATCHES threads)
     set(pic OFF)
     set(target_flags -pthread)
@@ -271,7 +285,7 @@ function(define_libcxx_sub target target_suffix extra_target_flags extra_libdir_
     --target=${target}
     ${dir_compile_opts}
     ${dir_link_opts}
-    --sysroot ${wasi_sysroot}
+    --sysroot ${sysroot}
     -resource-dir ${wasi_resource_dir})
 
   set(exnsuffix "")
@@ -309,6 +323,12 @@ function(define_libcxx_sub target target_suffix extra_target_flags extra_libdir_
     set(shared OFF)
   endif()
 
+  # FIXME(WebAssembly/wasi-libc#813) - shared libraries don't work with coop
+  # threads right now.
+  if (${sysroot} STREQUAL ${coop_threads_sysroot})
+    set(shared OFF)
+  endif()
+
   set(extra_cflags_list ${CMAKE_C_FLAGS} ${extra_flags})
   list(JOIN extra_cflags_list " " extra_cflags)
   set(extra_cxxflags_list ${CMAKE_CXX_FLAGS} ${extra_flags})
@@ -318,10 +338,11 @@ function(define_libcxx_sub target target_suffix extra_target_flags extra_libdir_
     SOURCE_DIR ${llvm_proj_dir}/runtimes
     CMAKE_ARGS
       ${default_cmake_args}
+      -DCMAKE_SYSROOT=${sysroot}
       # Ensure headers are installed in a target-specific path instead of a
       # target-generic path.
-      -DCMAKE_INSTALL_INCLUDEDIR=${wasi_sysroot}/include/${target}${exnsuffix}
-      -DCMAKE_STAGING_PREFIX=${wasi_sysroot}
+      -DCMAKE_INSTALL_INCLUDEDIR=${sysroot}/include/${target}${exnsuffix}
+      -DCMAKE_STAGING_PREFIX=${sysroot}
       -DCMAKE_POSITION_INDEPENDENT_CODE=${pic}
       -DLIBCXX_ENABLE_THREADS:BOOL=ON
       -DLIBCXX_HAS_PTHREAD_API:BOOL=ON
@@ -382,12 +403,12 @@ function(define_libcxx_sub target target_suffix extra_target_flags extra_libdir_
   add_dependencies(libcxx-${target} libcxx-${target}${target_suffix}-build)
 endfunction()
 
-function(define_libcxx_and_lto target target_suffix exceptions)
-  define_libcxx_sub(${target} "${target_suffix}" "" "" ${exceptions})
+function(define_libcxx_and_lto sysroot target target_suffix exceptions)
+  define_libcxx_sub(${sysroot} ${target} "${target_suffix}" "" "" ${exceptions})
   if (WASI_SDK_LTO)
     # Note: clang knows this /llvm-lto/${llvm_version} convention.
     # https://github.com/llvm/llvm-project/blob/llvmorg-18.1.8/clang/lib/Driver/ToolChains/WebAssembly.cpp#L204-L210
-    define_libcxx_sub(${target} ${target_suffix}-lto "-flto=full" "/llvm-lto/${llvm_version}" ${exceptions})
+    define_libcxx_sub(${sysroot} ${target} ${target_suffix}-lto "-flto=full" "/llvm-lto/${llvm_version}" ${exceptions})
   endif()
 endfunction()
 
@@ -401,20 +422,32 @@ function(define_libcxx target)
   # Otherwise there's only one build of libcxx and it's either got exceptions or
   # it doesn't depending on configuration.
   if (WASI_SDK_EXCEPTIONS STREQUAL "DUAL")
-    define_libcxx_and_lto(${target} "" OFF)
-    define_libcxx_and_lto(${target} "-exn" ON)
+    define_libcxx_and_lto(${wasi_sysroot} ${target} "" OFF)
+    define_libcxx_and_lto(${wasi_sysroot} ${target} "-exn" ON)
   elseif(WASI_SDK_EXCEPTIONS STREQUAL "ON")
-    define_libcxx_and_lto(${target} "" ON)
+    define_libcxx_and_lto(${wasi_sysroot} ${target} "" ON)
   else()
-    define_libcxx_and_lto(${target} "" OFF)
+    define_libcxx_and_lto(${wasi_sysroot} ${target} "" OFF)
   endif()
 
+
   # As of this writing, `clang++` will ignore the target-specific include dirs
   # unless this one also exists:
   add_custom_target(libcxx-${target}-extra-dir
     COMMAND ${CMAKE_COMMAND} -E make_directory ${wasi_sysroot}/include/c++/v1
     COMMENT "creating libcxx-specific header file folder")
   add_dependencies(libcxx-${target} libcxx-${target}-extra-dir)
+
+  # Temporary wasip3 experimental coop threads sysroot before it's enabled by
+  # default.
+  if (${target} STREQUAL wasm32-wasip3 AND ${COOP_THREADS_POSSIBLE})
+    define_libcxx_and_lto(${coop_threads_sysroot} ${target} "-coop" OFF)
+
+    add_custom_target(libcxx-${target}-extra-dir-coop-threads-sysroot
+      COMMAND ${CMAKE_COMMAND} -E make_directory ${coop_threads_sysroot}/include/c++/v1
+      COMMENT "creating libcxx-specific header file folder")
+    add_dependencies(libcxx-${target} libcxx-${target}-extra-dir-coop-threads-sysroot)
+  endif()
 endfunction()
 
 foreach(target IN LISTS WASI_SDK_TARGETS)

src/llvm-prs-208263-208332-208597.patch

@@ -73,7 +73,7 @@ index f3ff646cc3b1..2dd18d604df4 100644
  # COMPRESS:   42 03                             i64.const 3
 
 diff --git a/lld/test/wasm/cooperative-threading.s b/lld/test/wasm/cooperative-threading.s
-index 8b0f7eb1c256..0db72053692b 100644
+index 8b0f7eb1c256..7b891febbb03 100644
 --- a/lld/test/wasm/cooperative-threading.s
 +++ b/lld/test/wasm/cooperative-threading.s
 @@ -2,7 +2,7 @@
@@ -156,7 +156,7 @@ index 8b0f7eb1c256..0db72053692b 100644
 +# CHECK-NEXT:         Value:           65536
 +# CHECK-NEXT:     - Index:           1
 +# CHECK-NEXT:       Type:            I32
-+# CHECK-NEXT:       Mutable:         false
++# CHECK-NEXT:       Mutable:         true
 +# CHECK-NEXT:       InitExpr:
 +# CHECK-NEXT:         Opcode:          I32_CONST
 +# CHECK-NEXT:         Value:           65544
@@ -534,7 +534,7 @@ index 9679074d6a0d..b5d130417774 100644
  # ASM-NEXT:                 i32.store 0
  # ASM-NEXT:                 i32.const 12
 diff --git a/lld/wasm/Driver.cpp b/lld/wasm/Driver.cpp
-index 9a2e3a82a927..35892c283897 100644
+index 9a2e3a82a927..2389c8f88a01 100644
 --- a/lld/wasm/Driver.cpp
 +++ b/lld/wasm/Driver.cpp
 @@ -759,6 +759,14 @@ static void setConfigs() {
@@ -552,28 +552,30 @@ index 9a2e3a82a927..35892c283897 100644
    }
  }
 
-@@ -970,12 +978,20 @@ static void createSyntheticSymbols() {
+@@ -970,12 +978,22 @@ static void createSyntheticSymbols() {
    }
 
    if (ctx.arg.isMultithreaded()) {
 -    // TLS symbols are all hidden/dso-local
 +    // TLS symbols are all hidden/dso-local, and note that the `tlsBase` global
 +    // serves a different purpose depending on `libcallThreadContext`. If
 +    // `libcallThreadContext` is `false` it's the base address of TLS and it's
-+    // initialized fresh by each thread. This requires a mutable global.
-+    //
-+    // If `libcallThreadContext` is `true`, however, then it records the
-+    // initial thread's TLS address at `start`-time. In non-PIC mode this is a
-+    // constant determined during linking, but in PIC mode it's calculated
-+    // during instantiation.
++    // initialized fresh by each thread. If `libcallThreadContext` is `true`,
++    // however, then it records the initial thread's TLS address at
++    // `start`-time. In non-PIC mode this is a constant determined during
++    // linking, but in PIC mode it's calculated during instantiation. For
++    // simplicity this global is always mutable despite technically not being
++    // necessary in `libcallThreadContext` non-PIC mode. Given that the global
++    // type must match across linkage units it's easier to have it always be one
++    // type instead of depending on flags, for example it means that `libc.a`
++    // (not PIC) is compatible with `libc.so` (PIC) for linking.
      auto tls_base_name =
          ctx.arg.libcallThreadContext ? "__init_tls_base" : "__tls_base";
 -    ctx.sym.tlsBase =
 -        createGlobalVariable(tls_base_name, !ctx.arg.libcallThreadContext,
 -                             WASM_SYMBOL_VISIBILITY_HIDDEN);
-+    ctx.sym.tlsBase = createGlobalVariable(
-+        tls_base_name, !ctx.arg.libcallThreadContext || ctx.isPic,
-+        WASM_SYMBOL_VISIBILITY_HIDDEN);
++    ctx.sym.tlsBase = createGlobalVariable(tls_base_name, true,
++                                           WASM_SYMBOL_VISIBILITY_HIDDEN);
      ctx.sym.tlsSize = createGlobalVariable("__tls_size", false,
                                             WASM_SYMBOL_VISIBILITY_HIDDEN);
      ctx.sym.tlsAlign = createGlobalVariable("__tls_align", false,