[WebAssembly] WASIP3 and component model threading support

clang/include/clang/Options/Options.td

@@ -5670,6 +5670,8 @@ def mcall_indirect_overlong : Flag<["-"], "mcall-indirect-overlong">, Group<m_wa
 def mno_call_indirect_overlong : Flag<["-"], "mno-call-indirect-overlong">, Group<m_wasm_Features_Group>;
 def mcompact_imports : Flag<["-"], "mcompact-imports">, Group<m_wasm_Features_Group>;
 def mno_compact_imports : Flag<["-"], "mno-compact-imports">, Group<m_wasm_Features_Group>;
+def mcomponent_model_thread_context : Flag<["-"], "mcomponent-model-thread-context">, Group<m_wasm_Features_Group>;
+def mno_component_model_thread_context : Flag<["-"], "mno-component-model-thread-context">, Group<m_wasm_Features_Group>;
 def mexception_handing : Flag<["-"], "mexception-handling">, Group<m_wasm_Features_Group>;
 def mno_exception_handing : Flag<["-"], "mno-exception-handling">, Group<m_wasm_Features_Group>;
 def mextended_const : Flag<["-"], "mextended-const">, Group<m_wasm_Features_Group>;

clang/lib/Basic/Targets/WebAssembly.cpp

@@ -56,6 +56,7 @@ bool WebAssemblyTargetInfo::hasFeature(StringRef Feature) const {
       .Case("bulk-memory", HasBulkMemory)
       .Case("bulk-memory-opt", HasBulkMemoryOpt)
       .Case("call-indirect-overlong", HasCallIndirectOverlong)
+      .Case("component-model-thread-context", HasComponentModelThreadContext)
       .Case("compact-imports", HasCompactImports)
       .Case("exception-handling", HasExceptionHandling)
       .Case("extended-const", HasExtendedConst)
@@ -120,6 +121,8 @@ void WebAssemblyTargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("__wasm_tail_call__");
   if (HasWideArithmetic)
     Builder.defineMacro("__wasm_wide_arithmetic__");
+  if (HasComponentModelThreadContext)
+    Builder.defineMacro("__wasm_component_model_thread_context__");
   // Note that not all wasm features appear here.   For example,
   // HasCompatctImports
 
@@ -374,6 +377,14 @@ bool WebAssemblyTargetInfo::handleTargetFeatures(
       HasWideArithmetic = false;
       continue;
     }
+    if (Feature == "+component-model-thread-context") {
+      HasComponentModelThreadContext = true;
+      continue;
+    }
+    if (Feature == "-component-model-thread-context") {
+      HasComponentModelThreadContext = false;
+      continue;
+    }
 
     Diags.Report(diag::err_opt_not_valid_with_opt)
         << Feature << "-target-feature";
@@ -407,10 +418,11 @@ WebAssemblyTargetInfo::getTargetBuiltins() const {
 void WebAssemblyTargetInfo::adjust(DiagnosticsEngine &Diags, LangOptions &Opts,
                                    const TargetInfo *Aux) {
   TargetInfo::adjust(Diags, Opts, Aux);
-  // Turn off POSIXThreads and ThreadModel so that we don't predefine _REENTRANT
-  // or __STDCPP_THREADS__ if we will eventually end up stripping atomics
-  // because they are unsupported.
-  if (!HasAtomics || !HasBulkMemory) {
+  // If not using component model threading intrinsics, turn off POSIXThreads 
+  // and ThreadModel so that we don't predefine _REENTRANT or __STDCPP_THREADS__ 
+  // if we will eventually end up stripping atomics because they are unsupported.
+  if (!HasComponentModelThreadContext &&
+      (!HasAtomics || !HasBulkMemory)) {
     Opts.POSIXThreads = false;
     Opts.setThreadModel(LangOptions::ThreadModelKind::Single);
     Opts.ThreadsafeStatics = false;

clang/lib/Basic/Targets/WebAssembly.h

@@ -63,6 +63,7 @@ class LLVM_LIBRARY_VISIBILITY WebAssemblyTargetInfo : public TargetInfo {
   bool HasBulkMemoryOpt = false;
   bool HasCallIndirectOverlong = false;
   bool HasCompactImports = false;
+  bool HasComponentModelThreadContext = false;
   bool HasExceptionHandling = false;
   bool HasExtendedConst = false;
   bool HasFP16 = false;

clang/lib/Driver/ToolChains/WebAssembly.cpp

@@ -79,6 +79,19 @@ static bool WantsPthread(const llvm::Triple &Triple, const ArgList &Args) {
   return WantsPthread;
 }
 
+static bool WantsComponentModelThreadContext(const llvm::Triple &Triple, const ArgList &Args) {
+  // If the target is WASIP3, then enable the
+  // component-model-thread-context feature by default, unless explicitly
+  // disabled.
+  return Triple.getOS() == llvm::Triple::WASIp3 &&
+         Args.hasFlag(options::OPT_mcomponent_model_thread_context,
+                     options::OPT_mno_component_model_thread_context, true);
+}
+
+static bool WantsSharedMemory(const llvm::Triple &Triple, const ArgList &Args) {
+  return WantsPthread(Triple, Args) && !WantsComponentModelThreadContext(Triple, Args);
+}
+
 void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                 const InputInfo &Output,
                                 const InputInfoList &Inputs,
@@ -160,7 +173,7 @@ void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
 
-  if (WantsPthread(ToolChain.getTriple(), Args))
+  if (WantsSharedMemory(ToolChain.getTriple(), Args))
     CmdArgs.push_back("--shared-memory");
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
@@ -307,36 +320,45 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
                           options::OPT_fno_use_init_array, true))
     CC1Args.push_back("-fno-use-init-array");
 
-  // '-pthread' implies atomics, bulk-memory, mutable-globals, and sign-ext
+  if (WantsComponentModelThreadContext(getTriple(), DriverArgs)) {
+    CC1Args.push_back("-target-feature");
+    CC1Args.push_back("+component-model-thread-context");
+  }
+
+  // '-pthread' implies bulk-memory, and, if shared memory is also used,
+  // also implies atomics, mutable-globals, and sign-ext.
   if (WantsPthread(getTriple(), DriverArgs)) {
-    if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
-                           false))
-      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-          << "-pthread"
-          << "-mno-atomics";
     if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
                            options::OPT_mbulk_memory, false))
       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
           << "-pthread"
           << "-mno-bulk-memory";
-    if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
-                           options::OPT_mmutable_globals, false))
-      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-          << "-pthread"
-          << "-mno-mutable-globals";
-    if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
-                           false))
-      getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-          << "-pthread"
-          << "-mno-sign-ext";
-    CC1Args.push_back("-target-feature");
-    CC1Args.push_back("+atomics");
     CC1Args.push_back("-target-feature");
     CC1Args.push_back("+bulk-memory");
-    CC1Args.push_back("-target-feature");
-    CC1Args.push_back("+mutable-globals");
-    CC1Args.push_back("-target-feature");
-    CC1Args.push_back("+sign-ext");
+
+    if (WantsSharedMemory(getTriple(), DriverArgs)) {
+      if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
+                             false))
+        getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+            << "-pthread"
+            << "-mno-atomics";
+      if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
+                             options::OPT_mmutable_globals, false))
+        getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+            << "-pthread"
+            << "-mno-mutable-globals";
+      if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
+                             false))
+        getDriver().Diag(diag::err_drv_argument_not_allowed_with)
+            << "-pthread"
+            << "-mno-sign-ext";
+      CC1Args.push_back("-target-feature");
+      CC1Args.push_back("+atomics");
+      CC1Args.push_back("-target-feature");
+      CC1Args.push_back("+mutable-globals");
+      CC1Args.push_back("-target-feature");
+      CC1Args.push_back("+sign-ext");
+    }
   }
 
   if (!DriverArgs.hasFlag(options::OPT_mmutable_globals,

clang/test/Driver/wasm-features.c

@@ -112,3 +112,10 @@
 
 // COMPACT-IMPORTS: "-target-feature" "+compact-imports"
 // NO-COMPACT-IMPORTS: "-target-feature" "-compact-imports"
+
+// RUN: %clang --target=wasm32-unknown-unknown -### %s -mcomponent-model-thread-context 2>&1 | FileCheck %s -check-prefix=COMPONENT-MODEL-THREAD-CONTEXT
+// RUN: %clang --target=wasm32-unknown-unknown -### %s -mno-component-model-thread-context 2>&1 | FileCheck %s -check-prefix=NO-COMPONENT-MODEL-THREAD-CONTEXT
+
+// COMPONENT-MODEL-THREAD-CONTEXT: "-target-feature" "+component-model-thread-context"
+// NO-COMPONENT-MODEL-THREAD-CONTEXT: "-target-feature" "-component-model-thread-context"
+

clang/test/Driver/wasm-toolchain.c

@@ -77,13 +77,13 @@
 // '-pthread' sets +atomics, +bulk-memory, +mutable-globals, +sign-ext, and --shared-memory
 // RUN: %clang -### --target=wasm32-unknown-unknown --sysroot=/foo %s -pthread 2>&1 \
 // RUN:  | FileCheck -check-prefix=PTHREAD %s
-// PTHREAD: "-cc1" {{.*}} "-target-feature" "+atomics" "-target-feature" "+bulk-memory" "-target-feature" "+mutable-globals" "-target-feature" "+sign-ext"
+// PTHREAD: "-cc1" {{.*}} "-target-feature" "+bulk-memory" "-target-feature" "+atomics" "-target-feature" "+mutable-globals" "-target-feature" "+sign-ext"
 // PTHREAD: wasm-ld{{.*}}" "--shared-memory" "-lpthread"
 //
 // '-pthread' with '-nostdlib' should still set '--shared-memory' but not include '-lpthread'
 // RUN: %clang -### --target=wasm32-unknown-unknown --sysroot=/foo %s -pthread -nostdlib 2>&1 \
 // RUN:  | FileCheck -check-prefix=PTHREAD-NOSTDLIB %s
-// PTHREAD-NOSTDLIB: "-cc1" {{.*}} "-target-feature" "+atomics" "-target-feature" "+bulk-memory" "-target-feature" "+mutable-globals" "-target-feature" "+sign-ext"
+// PTHREAD-NOSTDLIB: "-cc1" {{.*}} "-target-feature" "+bulk-memory" "-target-feature" "+atomics" "-target-feature" "+mutable-globals" "-target-feature" "+sign-ext"
 // PTHREAD-NOSTDLIB: wasm-ld{{.*}}" "--shared-memory" "-o" "a.out"
 
 // '-pthread' not allowed with '-mno-atomics'
@@ -113,7 +113,7 @@
 // 'wasm32-wasi-threads' does the same thing as '-pthread'
 // RUN: %clang -### --target=wasm32-wasi-threads --sysroot=/foo %s 2>&1 \
 // RUN:  | FileCheck -check-prefix=WASI_THREADS %s
-// WASI_THREADS: "-cc1" {{.*}} "-target-feature" "+atomics" "-target-feature" "+bulk-memory" "-target-feature" "+mutable-globals" "-target-feature" "+sign-ext"
+// WASI_THREADS: "-cc1" {{.*}} "-target-feature" "+bulk-memory" "-target-feature" "+atomics" "-target-feature" "+mutable-globals" "-target-feature" "+sign-ext"
 // WASI_THREADS: wasm-ld{{.*}}" "--shared-memory" "-lpthread"
 
 // '-mllvm -emscripten-cxx-exceptions-allowed=foo,bar' sets
@@ -303,3 +303,15 @@
 // RUN:   | FileCheck -check-prefix=LINK_WALI_BASIC %s
 // LINK_WALI_BASIC: "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
 // LINK_WALI_BASIC: wasm-ld{{.*}}" "-L/foo/lib/wasm32-linux-muslwali" "crt1.o" "[[temp]]" "-lc" "{{.*[/\\]}}libclang_rt.builtins.a" "-o" "a.out"
+
+// `wasm32-wasip3` passes `+component-model-thread-context` by default.
+
+// RUN: %clang -### --target=wasm32-wasip3 --sysroot=/foo %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=LINK_WASIP3_THREAD_CONTEXT %s
+// LINK_WASIP3_THREAD_CONTEXT: "-cc1" {{.*}} "-target-feature" "+component-model-thread-context"
+
+// `wasm32-wasip3` does not pass `+component-model-thread-context` when `-mno-component-model-thread-context` is used.
+
+// RUN: %clang -### --target=wasm32-wasip3 --sysroot=/foo -mno-component-model-thread-context %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=LINK_WASIP3_NO_THREAD_CONTEXT %s
+// LINK_WASIP3_NO_THREAD_CONTEXT: "-cc1" {{.*}} "-target-feature" "-component-model-thread-context"

clang/test/Preprocessor/wasm-target-features.c

@@ -239,3 +239,12 @@
 // RUN:   | FileCheck %s -check-prefix=WIDE-ARITHMETIC
 //
 // WIDE-ARITHMETIC: #define __wasm_wide_arithmetic__ 1{{$}}
+
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm32-unknown-unknown -mcomponent-model-thread-context \
+// RUN:   | FileCheck %s -check-prefix=COMPONENT-MODEL-THREAD-CONTEXT
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm64-unknown-unknown -mcomponent-model-thread-context \
+// RUN:   | FileCheck %s -check-prefix=COMPONENT-MODEL-THREAD-CONTEXT
+
+// COMPONENT-MODEL-THREAD-CONTEXT: #define __wasm_component_model_thread_context__ 1{{$}}

lld/test/wasm/Inputs/disallow-component-model-thread-context.s

@@ -0,0 +1,6 @@
+# Mark the feature as DISALLOWED
+.section  .custom_section.target_features,"",@
+  .int8 1
+  .int8 45
+  .int8 30
+  .ascii  "component-model-thread-context"

lld/test/wasm/Inputs/stack-pointer.s

@@ -0,0 +1,11 @@
+.globaltype __stack_pointer, i32
+
+.globl  _start
+_start:
+  .functype _start () -> (i32)
+  global.get __stack_pointer
+  i32.const 16
+  i32.sub
+  drop
+  i32.const 0
+  end_function

lld/test/wasm/Inputs/use-component-model-thread-context.s

@@ -0,0 +1,6 @@
+# Mark the feature as USED
+.section  .custom_section.target_features,"",@
+  .int8 1
+  .int8 43
+  .int8 30
+  .ascii  "component-model-thread-context"

lld/test/wasm/archive-export.test

@@ -14,9 +14,6 @@ CHECK:         Exports:
 CHECK-NEXT:       - Name:            memory
 CHECK-NEXT:         Kind:            MEMORY
 CHECK-NEXT:         Index:           0
-CHECK-NEXT:       - Name:            __stack_pointer
-CHECK-NEXT:         Kind:            GLOBAL
-CHECK-NEXT:         Index:           0
 CHECK-NEXT:       - Name:            foo
 CHECK-NEXT:         Kind:            FUNCTION
 CHECK-NEXT:         Index:           1
@@ -29,6 +26,9 @@ CHECK-NEXT:         Index:           3
 CHECK-NEXT:       - Name:            _start
 CHECK-NEXT:         Kind:            FUNCTION
 CHECK-NEXT:         Index:           0
+CHECK-NEXT:       - Name:            __stack_pointer
+CHECK-NEXT:         Kind:            GLOBAL
+CHECK-NEXT:         Index:           0
 CHECK-NEXT:   - Type:            CODE
 
 NOEXPORT:         Exports:

lld/test/wasm/comdats.ll

@@ -35,9 +35,6 @@ entry:
 ; CHECK-NEXT:      - Name:            memory
 ; CHECK-NEXT:        Kind:            MEMORY
 ; CHECK-NEXT:        Index:           0
-; CHECK-NEXT:      - Name:            __stack_pointer
-; CHECK-NEXT:        Kind:            GLOBAL
-; CHECK-NEXT:        Index:           0
 ; CHECK-NEXT:      - Name:            _start
 ; CHECK-NEXT:        Kind:            FUNCTION
 ; CHECK-NEXT:        Index:           1
@@ -53,6 +50,9 @@ entry:
 ; CHECK-NEXT:      - Name:            callComdatFn2
 ; CHECK-NEXT:        Kind:            FUNCTION
 ; CHECK-NEXT:        Index:           5
+; CHECK-NEXT:      - Name:            __stack_pointer
+; CHECK-NEXT:        Kind:            GLOBAL
+; CHECK-NEXT:        Index:           0
 ; CHECK-NEXT:  - Type:            ELEM
 ; CHECK-NEXT:    Segments:
 ; CHECK-NEXT:      - Offset:

lld/test/wasm/mutable-global-exports.s

@@ -57,12 +57,12 @@ _start:
 # CHECK-SP-NEXT:      - Name:            memory
 # CHECK-SP-NEXT:        Kind:            MEMORY
 # CHECK-SP-NEXT:        Index:           0
-# CHECK-SP-NEXT:      - Name:            __stack_pointer
-# CHECK-SP-NEXT:        Kind:            GLOBAL
-# CHECK-SP-NEXT:        Index:           0
 # CHECK-SP-NEXT:      - Name:            _start
 # CHECK-SP-NEXT:        Kind:            FUNCTION
 # CHECK-SP-NEXT:        Index:           0
+# CHECK-SP-NEXT:      - Name:            __stack_pointer
+# CHECK-SP-NEXT:        Kind:            GLOBAL
+# CHECK-SP-NEXT:        Index:           0
 # CHECK-SP-NEXT:  - Type:            CODE
 
 #      CHECK-ALL:  - Type:            EXPORT
@@ -73,9 +73,6 @@ _start:
 # CHECK-ALL-NEXT:      - Name:            __wasm_call_ctors
 # CHECK-ALL-NEXT:        Kind:            FUNCTION
 # CHECK-ALL-NEXT:        Index:           0
-# CHECK-ALL-NEXT:      - Name:            __stack_pointer
-# CHECK-ALL-NEXT:        Kind:            GLOBAL
-# CHECK-ALL-NEXT:        Index:           0
 # CHECK-ALL-NEXT:      - Name:            _start
 # CHECK-ALL-NEXT:        Kind:            FUNCTION
 # CHECK-ALL-NEXT:        Index:           1
@@ -85,6 +82,9 @@ _start:
 # CHECK-ALL-NEXT:      - Name:            bar_global
 # CHECK-ALL-NEXT:        Kind:            GLOBAL
 # CHECK-ALL-NEXT:        Index:           5
+# CHECK-ALL-NEXT:      - Name:            __stack_pointer
+# CHECK-ALL-NEXT:        Kind:            GLOBAL
+# CHECK-ALL-NEXT:        Index:           0
 # CHECK-ALL-NEXT:      - Name:            __dso_handle
 # CHECK-ALL-NEXT:        Kind:            GLOBAL
 # CHECK-ALL-NEXT:        Index:           6

lld/test/wasm/pie.s

@@ -98,6 +98,10 @@ _start:
 # CHECK-NEXT:         GlobalType:      I32
 # CHECK-NEXT:         GlobalMutable:   true
 # CHECK-NEXT:       - Module:          env
+# CHECK-NEXT:         Field:           external_func
+# CHECK-NEXT:         Kind:            FUNCTION
+# CHECK-NEXT:         SigIndex:        1
+# CHECK-NEXT:       - Module:          env
 # CHECK-NEXT:         Field:           __memory_base
 # CHECK-NEXT:         Kind:            GLOBAL
 # CHECK-NEXT:         GlobalType:      I32

lld/test/wasm/shared-weak-symbols.s

@@ -42,6 +42,10 @@ call_weak:
 # CHECK-NEXT:        Memory:
 # CHECK-NEXT:          Minimum:         0x0
 # CHECK-NEXT:      - Module:          env
+# CHECK-NEXT:        Field:           weak_func
+# CHECK-NEXT:        Kind:            FUNCTION
+# CHECK-NEXT:        SigIndex:        0
+# CHECK-NEXT:      - Module:          env
 # CHECK-NEXT:        Field:           __memory_base
 # CHECK-NEXT:        Kind:            GLOBAL
 # CHECK-NEXT:        GlobalType:      I32
@@ -51,10 +55,6 @@ call_weak:
 # CHECK-NEXT:        Kind:            GLOBAL
 # CHECK-NEXT:        GlobalType:      I32
 # CHECK-NEXT:        GlobalMutable:   false
-# CHECK-NEXT:      - Module:          env
-# CHECK-NEXT:        Field:           weak_func
-# CHECK-NEXT:        Kind:            FUNCTION
-# CHECK-NEXT:        SigIndex:        0
 # CHECK-NEXT:  - Type:            FUNCTION
 
 # CHECK:        - Type:            EXPORT

lld/test/wasm/stack-pointer-abi.s

@@ -0,0 +1,15 @@
+# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t-component-model.o %S/Inputs/use-component-model-thread-context.s
+# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t-global.o %S/Inputs/disallow-component-model-thread-context.s
+# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s
+# RUN: wasm-ld --component-model-thread-context -o %t-component-model.wasm %t-component-model.o %t.o
+# RUN: obj2yaml %t-component-model.wasm | FileCheck %s --check-prefix=COMPONENT-MODEL
+# RUN: wasm-ld -o %t-original.wasm %t-global.o %t.o
+# RUN: obj2yaml %t-original.wasm | FileCheck %s --check-prefix=GLOBAL
+
+  .globl  _start
+_start:
+  .functype _start () -> ()
+  end_function
+
+# COMPONENT-MODEL: Name: __init_stack_pointer
+# GLOBAL: Name: __stack_pointer