[clang] nonblocking/nonallocating attributes (was: nolock/noalloc) (PR #84983)

[Chris Apple via cfe-commits]

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@@ -0,0 +1,124 @@
+// RUN: %clang_cc1 %s -ast-dump -fblocks | FileCheck %s
+
+// Make sure that the attribute gets parsed and attached to the correct AST elements.
+
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+// =========================================================================================
+// Square brackets, true
+
+namespace square_brackets {
+
+// On the type of the FunctionDecl
+void nl_function() [[clang::nonblocking]];
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nonblocking))'
+
+// On the type of the VarDecl holding a function pointer
+void (*nl_func_a)() [[clang::nonblocking]];
+// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nonblocking))'
+
+// On the type of the ParmVarDecl of a function parameter
+static void nlReceiver(void (*nl_func)() [[clang::nonblocking]]);
+// CHECK: ParmVarDecl {{.*}} nl_func 'void (*)() __attribute__((clang_nonblocking))'
+
+// As an AttributedType within the nested types of a typedef
+typedef void (*nl_fp_type)() [[clang::nonblocking]];
+// CHECK: TypedefDecl {{.*}} nl_fp_type 'void (*)() __attribute__((clang_nonblocking))'
+using nl_fp_talias = void (*)() [[clang::nonblocking]];
+// CHECK: TypeAliasDecl {{.*}} nl_fp_talias 'void (*)() __attribute__((clang_nonblocking))'
+
+// From a typedef or typealias, on a VarDecl
+nl_fp_type nl_fp_var1;
+// CHECK: VarDecl {{.*}} nl_fp_var1 'nl_fp_type':'void (*)() __attribute__((clang_nonblocking))'
+nl_fp_talias nl_fp_var2;
+// CHECK: VarDecl {{.*}} nl_fp_var2 'nl_fp_talias':'void (*)() __attribute__((clang_nonblocking))'
+
+// On type of a FieldDecl
+struct Struct {
+	void (*nl_func_field)() [[clang::nonblocking]];
+// CHECK: FieldDecl {{.*}} nl_func_field 'void (*)() __attribute__((clang_nonblocking))'
+};
+
+// nonallocating should NOT be subsumed into nonblocking
+void nl1() [[clang::nonblocking]] [[clang::nonallocating]];
+// CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
+
+void nl2() [[clang::nonallocating]] [[clang::nonblocking]];
+// CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
+
+decltype(nl1) nl3;
+// CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
+
+// Attribute propagates from base class virtual method to overrides.
+struct Base {
+	virtual void nb_method() [[clang::nonblocking]];
+};
+struct Derived : public Base {
+	void nb_method() override;
+	// CHECK: CXXMethodDecl {{.*}} nb_method 'void () __attribute__((clang_nonblocking))'
+};
+
+// Dependent expression
+template <bool V>
+struct Dependent {
+	void nb_method2() [[clang::nonblocking(V)]];
+	// CHECK: CXXMethodDecl {{.*}} nb_method2 'void () __attribute__((clang_nonblocking(V)))'
+};
+
+// --- Blocks ---
+
+// On the type of the VarDecl holding a BlockDecl
+void (^nl_block1)() [[clang::nonblocking]] = ^() [[clang::nonblocking]] {};
+// CHECK: VarDecl {{.*}} nl_block1 'void (^)() __attribute__((clang_nonblocking))'
+
+int (^nl_block2)() [[clang::nonblocking]] = ^() [[clang::nonblocking]] { return 0; };
+// CHECK: VarDecl {{.*}} nl_block2 'int (^)() __attribute__((clang_nonblocking))'
+
+// The operand of the CallExpr is an ImplicitCastExpr of a DeclRefExpr -> nl_block which hold the attribute
+static void blockCaller() { nl_block1(); }
+// CHECK: DeclRefExpr {{.*}} 'nl_block1' 'void (^)() __attribute__((clang_nonblocking))'
+
+// --- Lambdas ---
+
+// On the operator() of a lambda's CXXMethodDecl
+auto nl_lambda = []() [[clang::nonblocking]] {};
+// CHECK: CXXMethodDecl {{.*}} operator() 'void () const __attribute__((clang_nonblocking))' inline
+
+// =========================================================================================
+// Square brackets, false
+
+void nl_func_false() [[clang::blocking]];
+// CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_blocking))'
+
+// TODO: This exposes a bug where a type attribute is lost when inferring a lambda's
+// return type.
+auto nl_lambda_false = []() [[clang::blocking]] {};
+
+} // namespace square_brackets
+
+// =========================================================================================
+// GNU-style attribute, true
+
+// TODO: Duplicate more of the above for GNU-style attribute
+
+namespace gnu_style {
+
+// On the type of the FunctionDecl
+void nl_function() __attribute__((clang_nonblocking));
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nonblocking))'
+
+// Alternate placement on the FunctionDecl
+__attribute__((clang_nonblocking)) void nl_function();
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nonblocking))'
+
+// On the type of the VarDecl holding a function pointer
+void (*nl_func_a)() __attribute__((clang_nonblocking));
+// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nonblocking))'
+
+// Alternate attribute placement on VarDecl
+__attribute__((clang_nonblocking)) void (*nl_func_b)();
+// CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nonblocking))'
+
+} // namespace gnu_style
+
+// TODO: Duplicate the above for nonallocating
----------------
cjappl wrote:

Reminding on this TODO

https://github.com/llvm/llvm-project/pull/84983