[clang][WebAssembly] Support reftypes & varargs in test_function_pointer_signature

clang/lib/CodeGen/TargetBuiltins/WebAssembly.cpp

@@ -246,35 +246,26 @@ Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
     llvm::FunctionType *LLVMFuncTy =
         cast<llvm::FunctionType>(ConvertType(QualType(FuncTy, 0)));
 
+    bool VarArg = LLVMFuncTy->isVarArg();
     unsigned NParams = LLVMFuncTy->getNumParams();
     std::vector<Value *> Args;
-    Args.reserve(NParams + 3);
+    Args.reserve(NParams + 3 + VarArg);
     // The only real argument is the FuncRef
     Args.push_back(FuncRef);
 
     // Add the type information
-    auto addType = [this, &Args](llvm::Type *T) {
-      if (T->isVoidTy()) {
-        // Do nothing
-      } else if (T->isFloatingPointTy()) {
-        Args.push_back(ConstantFP::get(T, 0));
-      } else if (T->isIntegerTy()) {
-        Args.push_back(ConstantInt::get(T, 0));
-      } else if (T->isPointerTy()) {
-        Args.push_back(ConstantPointerNull::get(llvm::PointerType::get(
-            getLLVMContext(), T->getPointerAddressSpace())));
-      } else {
-        // TODO: Handle reference types. For now, we reject them in Sema.
-        llvm_unreachable("Unhandled type");
-      }
-    };
-
-    addType(LLVMFuncTy->getReturnType());
+    llvm::Type *RetType = LLVMFuncTy->getReturnType();
+    if (!RetType->isVoidTy()) {
+      Args.push_back(PoisonValue::get(RetType));
+    }
     // The token type indicates the boundary between return types and param
     // types.
     Args.push_back(PoisonValue::get(llvm::Type::getTokenTy(getLLVMContext())));
     for (unsigned i = 0; i < NParams; i++) {
-      addType(LLVMFuncTy->getParamType(i));
+      Args.push_back(PoisonValue::get(LLVMFuncTy->getParamType(i)));
+    }
+    if (VarArg) {
+      Args.push_back(PoisonValue::get(Builder.getPtrTy()));
     }
     Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_ref_test_func);
     return Builder.CreateCall(Callee, Args);

clang/lib/Sema/SemaWasm.cpp

@@ -250,24 +250,6 @@ bool SemaWasm::BuiltinWasmTestFunctionPointerSignature(CallExpr *TheCall) {
            << ArgType << FuncPtrArg->getSourceRange();
   }
 
-  // Check that the function pointer doesn't use reference types
-  if (FuncTy->getReturnType().isWebAssemblyReferenceType()) {
-    return Diag(
-               FuncPtrArg->getBeginLoc(),
-               diag::err_wasm_builtin_test_fp_sig_cannot_include_reference_type)
-           << 0 << FuncTy->getReturnType() << FuncPtrArg->getSourceRange();
-  }
-  auto NParams = FuncTy->getNumParams();
-  for (unsigned I = 0; I < NParams; I++) {
-    if (FuncTy->getParamType(I).isWebAssemblyReferenceType()) {
-      return Diag(
-                 FuncPtrArg->getBeginLoc(),
-                 diag::
-                     err_wasm_builtin_test_fp_sig_cannot_include_reference_type)
-             << 1 << FuncPtrArg->getSourceRange();
-    }
-  }
-
   // Set return type to int (the result of the test)
   TheCall->setType(getASTContext().IntTy);
 

clang/test/CodeGen/builtins-wasm.c

@@ -752,23 +752,66 @@ void *tp (void) {
   // WEBASSEMBLY: call {{.*}} @llvm.thread.pointer.p0()
 }
 
-typedef void (*Fvoid)(void);
-typedef float (*Ffloats)(float, double, int);
-typedef void (*Fpointers)(Fvoid, Ffloats, void*, int*, int***, char[5]);
 
 void use(int);
 
+typedef void (*Fvoid)(void);
 void test_function_pointer_signature_void(Fvoid func) {
   // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison)
   use(__builtin_wasm_test_function_pointer_signature(func));
 }
 
+typedef float (*Ffloats)(float, double, int);
 void test_function_pointer_signature_floats(Ffloats func) {
-  // WEBASSEMBLY:  tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, float 0.000000e+00, token poison, float 0.000000e+00, double 0.000000e+00, i32 0)
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, float poison, token poison, float poison, double poison, i32 poison)
   use(__builtin_wasm_test_function_pointer_signature(func));
 }
 
+typedef void (*Fpointers)(Fvoid, Ffloats, void*, int*, int***, char[5]);
 void test_function_pointer_signature_pointers(Fpointers func) {
-  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, ptr null, ptr null, ptr null, ptr null, ptr null, ptr null)
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, ptr poison, ptr poison, ptr poison, ptr poison, ptr poison, ptr poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
+typedef void (*FVarArgs)(int, ...);
+void test_function_pointer_signature_varargs(FVarArgs func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, i32 poison, ptr poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
+typedef __externref_t (*FExternRef)(__externref_t, __externref_t);
+void test_function_pointer_externref(FExternRef func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, ptr addrspace(10) poison, token poison, ptr addrspace(10) poison, ptr addrspace(10) poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
+typedef __funcref Fpointers (*FFuncRef)(__funcref Fvoid, __funcref Ffloats);
+void test_function_pointer_funcref(FFuncRef func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, ptr addrspace(20) poison, token poison, ptr addrspace(20) poison, ptr addrspace(20) poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
+// Some tests that we get struct ABIs correct. There is no special code in
+// __builtin_wasm_test_function_pointer_signature for this, it gets handled by
+// the normal type lowering code.
+// Single element structs are unboxed, multi element structs are passed on
+// stack.
+typedef struct {double x;} (*Fstructs1)(struct {double x;}, struct {float x;}, struct {double x; float y;});
+void test_function_pointer_structs1(Fstructs1 func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, double poison, token poison, double poison, float poison, ptr poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
+// Two element return struct ==> return ptr on stack
+typedef struct {double x; double y;} (*Fstructs2)(void);
+void test_function_pointer_structs2(Fstructs2 func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, ptr poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
+// Return union ==> return ptr on stack, one element union => unboxed
+typedef union {double x; float y;} (*FUnions)(union {double x; float y;}, union {double x;});
+void test_function_pointer_unions(FUnions func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, ptr poison, ptr poison, double poison)
   use(__builtin_wasm_test_function_pointer_signature(func));
 }

clang/test/Sema/builtins-wasm.c

@@ -57,8 +57,6 @@ void test_table_copy(int dst_idx, int src_idx, int nelem) {
 
 typedef void (*F1)(void);
 typedef int (*F2)(int);
-typedef int (*F3)(__externref_t);
-typedef __externref_t (*F4)(int);
 
 void test_function_pointer_signature() {
   // Test argument count validation
@@ -68,8 +66,6 @@ void test_function_pointer_signature() {
   // // Test argument type validation - should require function pointer
   (void)__builtin_wasm_test_function_pointer_signature((void*)0); // expected-error {{used type 'void *' where function pointer is required}}
   (void)__builtin_wasm_test_function_pointer_signature((int)0);   // expected-error {{used type 'int' where function pointer is required}}
-  (void)__builtin_wasm_test_function_pointer_signature((F3)0);   // expected-error {{not supported for function pointers with a reference type parameter}}
-  (void)__builtin_wasm_test_function_pointer_signature((F4)0);   // expected-error {{not supported for function pointers with a reference type return value}}
 
   // // Test valid usage
   int res = __builtin_wasm_test_function_pointer_signature((F1)0);

llvm/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp

@@ -136,6 +136,15 @@ static APInt encodeFunctionSignature(SelectionDAG *DAG, SDLoc &DL,
     if (VT == MVT::f64) {
       return wasm::ValType::F64;
     }
+    if (VT == MVT::externref) {
+      return wasm::ValType::EXTERNREF;
+    }
+    if (VT == MVT::funcref) {
+      return wasm::ValType::FUNCREF;
+    }
+    if (VT == MVT::exnref) {
+      return wasm::ValType::EXNREF;
+    }
     LLVM_DEBUG(errs() << "Unhandled type for llvm.wasm.ref.test.func: " << VT
                       << "\n");
     llvm_unreachable("Unhandled type for llvm.wasm.ref.test.func");

llvm/test/CodeGen/WebAssembly/ref-test-func.ll

@@ -31,7 +31,7 @@ define void @test_fpsig_return_i32(ptr noundef %func) local_unnamed_addr #0 {
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, i32 0)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, i32 poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
@@ -48,7 +48,7 @@ define void @test_fpsig_return_i64(ptr noundef %func) local_unnamed_addr #0 {
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, i64 0)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, i64 poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
@@ -65,7 +65,7 @@ define void @test_fpsig_return_f32(ptr noundef %func) local_unnamed_addr #0 {
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, float 0.)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, float poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
@@ -82,7 +82,7 @@ define void @test_fpsig_return_f64(ptr noundef %func) local_unnamed_addr #0 {
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, double 0.)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, double poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
@@ -100,7 +100,7 @@ define void @test_fpsig_param_i32(ptr noundef %func) local_unnamed_addr #0 {
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, double 0.)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, double poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
@@ -118,7 +118,7 @@ define void @test_fpsig_multiple_params_and_returns(ptr noundef %func) local_unn
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, i32 0, i64 0, float 0., double 0., token poison, i64 0, float 0., i64 0)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, i32 poison, i64 poison, float poison, double poison, token poison, i64 poison, float poison, i64 poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
@@ -137,10 +137,26 @@ define void @test_fpsig_ptrs(ptr noundef %func) local_unnamed_addr #0 {
 ; CHECK-NEXT:    call use
 ; CHECK-NEXT:    # fallthrough-return
 entry:
-  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, ptr null, token poison, ptr null, ptr null)
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, ptr poison, token poison, ptr poison, ptr poison)
   tail call void @use(i32 noundef %res) #3
   ret void
 }
 
+define void @test_reference_types(ptr noundef %func) local_unnamed_addr #0 {
+; CHECK-LABEL: test_reference_types:
+; CHK32:         .functype test_reference_types (i32) -> ()
+; CHK64:         .functype test_reference_types (i64) -> ()
+; CHECK-NEXT:  # %bb.0: # %entry
+; CHECK-NEXT:    local.get 0
+; CHK64-NEXT:    i32.wrap_i64
+; CHECK-NEXT:    table.get __indirect_function_table
+; CHECK-NEXT:    ref.test (funcref, externref) -> (externref)
+; CHECK-NEXT:    call use
+; CHECK-NEXT:    # fallthrough-return
+entry:
+  %res = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, ptr addrspace(10) poison, token poison, ptr addrspace(20) poison, ptr addrspace(10) poison)
+  tail call void @use(i32 noundef %res) #3
+  ret void
+}
 
 declare void @use(i32 noundef) local_unnamed_addr #1