gccrs: refactor builtins initialization and attributes

This commit performs builtin initialization in a more "GCC-y" way,
similarly to what the D frontend is doing. This way, we no longer have
to worry about invalid attributes or types when initializing them by
hand.

Also add attributes support through LANG_HOOKS_COMMON_ATTRIBUTE_TABLE
lang hook.

Most of these changes are based on D frontend.

gcc/rust/ChangeLog:

	* Make-lang.in (GRS_OBJS): Add rust-attribs.o.
	* backend/rust-builtins.cc (builtin_const, builtin_noreturn)
	(builtin_novops): Remove.
	(BuiltinsContext::lookup_simple_builtin): Adjust.
	(BuiltinsContext::setup_overflow_fns): Remove.
	(BuiltinsContext::define_function_type): Set builtin type to
	errormark so the builtin is considered unavailable.
	(BuiltinsContext::setup_math_fns): Remove.
	(BuiltinsContext::setup_atomic_fns): Remove.
	(build_c_type_nodes): Refactor based on D frontend.
	(BuiltinsContext::define_builtin_types): Likewise.
	(DEF_PRIMITIVE_TYPE): New.
	(DEF_FUNCTION_TYPE_0): New.
	(DEF_FUNCTION_TYPE_1): New.
	(DEF_FUNCTION_TYPE_2): New.
	(DEF_FUNCTION_TYPE_3): New.
	(DEF_FUNCTION_TYPE_4): New.
	(DEF_FUNCTION_TYPE_5): New.
	(DEF_FUNCTION_TYPE_6): New.
	(DEF_FUNCTION_TYPE_7): New.
	(DEF_FUNCTION_TYPE_8): New.
	(DEF_FUNCTION_TYPE_9): New.
	(DEF_FUNCTION_TYPE_10): New.
	(DEF_FUNCTION_TYPE_11): New.
	(DEF_FUNCTION_TYPE_VAR_0): New.
	(DEF_FUNCTION_TYPE_VAR_1): New.
	(DEF_FUNCTION_TYPE_VAR_2): New.
	(DEF_FUNCTION_TYPE_VAR_3): New.
	(DEF_FUNCTION_TYPE_VAR_4): New.
	(DEF_FUNCTION_TYPE_VAR_5): New.
	(DEF_FUNCTION_TYPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_7): New.
	(DEF_FUNCTION_TYPE_VAR_11): New.
	(DEF_POINTER_TYPE): New.
	(BuiltinsContext::setup): Adjust.
	(BuiltinsContext::define_builtin_attributes): New.
	(DEF_ATTR_NULL_TREE): New.
	(DEF_ATTR_INT): New.
	(DEF_ATTR_STRING): New.
	(DEF_ATTR_IDENT): New.
	(DEF_ATTR_TREE_LIST): New.
	(handle_flags): Remove.
	(BuiltinsContext::define_builtins): New.
	(DEF_BUILTIN): New.
	(BuiltinsContext::define_builtin): Remove.
	(BuiltinsContext::register_rust_mappings): New. Add all missing
	builtins.
	(BuiltinsContext::lookup_gcc_builtin): Adjust.
	* backend/rust-builtins.h (DEF_PRIMITIVE_TYPE): New.
	(DEF_FUNCTION_TYPE_0): New.
	(DEF_FUNCTION_TYPE_1): New.
	(DEF_FUNCTION_TYPE_2): New.
	(DEF_FUNCTION_TYPE_3): New.
	(DEF_FUNCTION_TYPE_4): New.
	(DEF_FUNCTION_TYPE_5): New.
	(DEF_FUNCTION_TYPE_6): New.
	(DEF_FUNCTION_TYPE_7): New.
	(DEF_FUNCTION_TYPE_8): New.
	(DEF_FUNCTION_TYPE_9): New.
	(DEF_FUNCTION_TYPE_10): New.
	(DEF_FUNCTION_TYPE_11): New.
	(DEF_FUNCTION_TYPE_VAR_0): New.
	(DEF_FUNCTION_TYPE_VAR_1): New.
	(DEF_FUNCTION_TYPE_VAR_2): New.
	(DEF_FUNCTION_TYPE_VAR_3): New.
	(DEF_FUNCTION_TYPE_VAR_4): New.
	(DEF_FUNCTION_TYPE_VAR_5): New.
	(DEF_FUNCTION_TYPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_7): New.
	(DEF_FUNCTION_TYPE_VAR_11): New.
	(DEF_POINTER_TYPE): New.
	(DEF_ATTR_NULL_TREE): New.
	(DEF_ATTR_INT): New.
	(DEF_ATTR_STRING): New.
	(DEF_ATTR_IDENT): New.
	(DEF_ATTR_TREE_LIST): New.
	* backend/rust-compile-intrinsic.cc (Intrinsics::compile): Add
	comment.
	(op_with_overflow_inner): Adjust.
	(copy_handler_inner): Adjust.
	(prefetch_data_handler): Adjust.
	(build_atomic_builtin_name): Adjust.
	(atomic_load_handler_inner): Adjust.
	(uninit_handler): Adjust.
	(move_val_init_handler): Adjust.
	(expect_handler_inner): Adjust.
	* rust-gcc.cc (fetch_overflow_builtins): Adjust.
	* rust-lang.cc (rust_localize_identifier): Adjust.
	(LANG_HOOKS_COMMON_ATTRIBUTE_TABLE): New.
	* rust-attribs.cc: New file.

gcc/testsuite/ChangeLog:

	* rust/compile/torture/intrinsics-4.rs: Adjust.
	* rust/compile/torture/intrinsics-math.rs: Adjust.
	* rust/execute/torture/atomic_load.rs: Adjust.
	* rust/execute/torture/atomic_store.rs: Adjust.
	* rust/compile/torture/intrinsics-1.rs: Removed.
	* rust/compile/torture/builtin_abort.rs: New test.
	* rust/execute/torture/builtin_abort.rs: New test.

Signed-off-by: Marc Poulhiès <[email protected]>
Co-authored-by: Arthur Cohen <[email protected]>

gcc/rust/Make-lang.in

@@ -64,6 +64,7 @@ gccrs$(exeext): $(GCCRS_D_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a $(LIBDEPS)
 # The compiler proper, not driver
 GRS_OBJS = \
     rust/rust-lang.o \
+    rust/rust-attribs.o \
     rust/rust-object-export.o \
     rust/rust-linemap.o \
     rust/rust-diagnostics.o \

gcc/rust/backend/rust-builtins.h

@@ -21,6 +21,7 @@
 #include "rust-tree.h"
 #include "langhooks.h"
 #include "tree.h"
+#include "selftest.h"
 
 namespace Rust {
 namespace Compile {
@@ -75,6 +76,7 @@ namespace Compile {
 //     _ => return None,
 // };
 // Some(cx.get_intrinsic(&llvm_name))
+
 class BuiltinsContext
 {
 public:
@@ -83,6 +85,110 @@ class BuiltinsContext
   bool lookup_simple_builtin (const std::string &name, tree *builtin);
 
 private:
+  enum Type
+  {
+#define DEF_PRIMITIVE_TYPE(NAME, V) NAME,
+#define DEF_FUNCTION_TYPE_0(NAME, R) NAME,
+#define DEF_FUNCTION_TYPE_1(NAME, R, A1) NAME,
+#define DEF_FUNCTION_TYPE_2(NAME, R, A1, A2) NAME,
+#define DEF_FUNCTION_TYPE_3(NAME, R, A1, A2, A3) NAME,
+#define DEF_FUNCTION_TYPE_4(NAME, R, A1, A2, A3, A4) NAME,
+#define DEF_FUNCTION_TYPE_5(NAME, R, A1, A2, A3, A4, A5) NAME,
+#define DEF_FUNCTION_TYPE_6(NAME, R, A1, A2, A3, A4, A5, A6) NAME,
+#define DEF_FUNCTION_TYPE_7(NAME, R, A1, A2, A3, A4, A5, A6, A7) NAME,
+#define DEF_FUNCTION_TYPE_8(NAME, R, A1, A2, A3, A4, A5, A6, A7, A8) NAME,
+#define DEF_FUNCTION_TYPE_9(NAME, R, A1, A2, A3, A4, A5, A6, A7, A8, A9) NAME,
+#define DEF_FUNCTION_TYPE_10(NAME, R, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10) \
+  NAME,
+#define DEF_FUNCTION_TYPE_11(NAME, R, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, \
+			     A11)                                              \
+  NAME,
+#define DEF_FUNCTION_TYPE_VAR_0(NAME, R) NAME,
+#define DEF_FUNCTION_TYPE_VAR_1(NAME, R, A1) NAME,
+#define DEF_FUNCTION_TYPE_VAR_2(NAME, R, A1, A2) NAME,
+#define DEF_FUNCTION_TYPE_VAR_3(NAME, R, A1, A2, A3) NAME,
+#define DEF_FUNCTION_TYPE_VAR_4(NAME, R, A1, A2, A3, A4) NAME,
+#define DEF_FUNCTION_TYPE_VAR_5(NAME, R, A1, A2, A3, A4, A5) NAME,
+#define DEF_FUNCTION_TYPE_VAR_6(NAME, R, A1, A2, A3, A4, A5, A6) NAME,
+#define DEF_FUNCTION_TYPE_VAR_7(NAME, R, A1, A2, A3, A4, A5, A6, A7) NAME,
+#define DEF_FUNCTION_TYPE_VAR_11(NAME, R, A1, A2, A3, A4, A5, A6, A7, A8, A9,  \
+				 A10, A11)                                     \
+  NAME,
+#define DEF_POINTER_TYPE(NAME, TYPE) NAME,
+
+#include "builtin-types.def"
+
+#undef DEF_PRIMITIVE_TYPE
+#undef DEF_FUNCTION_TYPE_0
+#undef DEF_FUNCTION_TYPE_1
+#undef DEF_FUNCTION_TYPE_2
+#undef DEF_FUNCTION_TYPE_3
+#undef DEF_FUNCTION_TYPE_4
+#undef DEF_FUNCTION_TYPE_5
+#undef DEF_FUNCTION_TYPE_6
+#undef DEF_FUNCTION_TYPE_7
+#undef DEF_FUNCTION_TYPE_8
+#undef DEF_FUNCTION_TYPE_9
+#undef DEF_FUNCTION_TYPE_10
+#undef DEF_FUNCTION_TYPE_11
+#undef DEF_FUNCTION_TYPE_VAR_0
+#undef DEF_FUNCTION_TYPE_VAR_1
+#undef DEF_FUNCTION_TYPE_VAR_2
+#undef DEF_FUNCTION_TYPE_VAR_3
+#undef DEF_FUNCTION_TYPE_VAR_4
+#undef DEF_FUNCTION_TYPE_VAR_5
+#undef DEF_FUNCTION_TYPE_VAR_6
+#undef DEF_FUNCTION_TYPE_VAR_7
+#undef DEF_FUNCTION_TYPE_VAR_11
+#undef DEF_POINTER_TYPE
+
+    BT_LAST,
+  };
+
+  enum Attr
+  {
+#define DEF_ATTR_NULL_TREE(ENUM) ENUM,
+#define DEF_ATTR_INT(ENUM, VALUE) ENUM,
+#define DEF_ATTR_STRING(ENUM, VALUE) ENUM,
+#define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
+#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
+
+#include "builtin-attrs.def"
+
+#undef DEF_ATTR_NULL_TREE
+#undef DEF_ATTR_INT
+#undef DEF_ATTR_STRING
+#undef DEF_ATTR_IDENT
+#undef DEF_ATTR_TREE_LIST
+
+    ATTR_LAST,
+  };
+
+  /**
+   * All builtin types, as defined in `builtin-types.def`
+   *
+   * This array is filled by the `define_builtin_types` method, during the first
+   * initialization of the `BuiltinsContext`
+   */
+  tree builtin_types[Type::BT_LAST + 1];
+
+  /**
+   * Similarly, this array contains all builtin attributes, as defined in
+   * `builtin-attr.def`
+   *
+   * This array is filled by the `define_builtin_attributes` method, during the
+   * first initialization of the `BuiltinsContext`
+   */
+  tree builtin_attributes[Attr::ATTR_LAST + 1];
+
+  void define_function_type (Type def, Type ret, bool is_variadic, size_t n,
+			     ...);
+  void define_builtin_types ();
+  void define_builtin_attributes ();
+  void define_builtins ();
+
+  void register_rust_mappings ();
+
   BuiltinsContext ();
 
   void setup_overflow_fns ();
@@ -91,20 +197,10 @@ class BuiltinsContext
 
   void setup ();
 
-  // Define a builtin function.  BCODE is the builtin function code
-  // defined by builtins.def.  NAME is the name of the builtin function.
-  // LIBNAME is the name of the corresponding library function, and is
-  // NULL if there isn't one.  FNTYPE is the type of the function.
-  // CONST_P is true if the function has the const attribute.
-  // NORETURN_P is true if the function has the noreturn attribute.
-  void define_builtin (const std::string rust_name, built_in_function bcode,
-		       const char *name, const char *libname, tree fntype,
-		       int flags);
-
   bool lookup_gcc_builtin (const std::string &name, tree *builtin);
 
   // A mapping of the GCC built-ins exposed to GCC Rust.
-  std::map<std::string, tree> builtin_functions_;
+  std::map<std::string, tree> builtin_functions;
   std::map<std::string, std::string> rust_intrinsic_to_gcc_builtin;
 };
 

gcc/rust/backend/rust-compile-intrinsic.cc

@@ -29,6 +29,8 @@
 #include "print-tree.h"
 #include "fold-const.h"
 #include "langhooks.h"
+#include "rust-gcc.h"
+#include "rust-constexpr.h"
 
 #include "print-tree.h"
 
@@ -243,13 +245,22 @@ static const std::map<std::string,
 
 Intrinsics::Intrinsics (Context *ctx) : ctx (ctx) {}
 
+/**
+ * Returns a FUNC_DECL corresponding to the intrinsic function FNTYPE. If a
+ * corresponding builtin exists, returns it. If not, search in the generic
+ * intrinsics declared and delegate the return to the corresponding handler.
+ *
+ * @param fntype The Rust function type that should be implemented by the
+ * compiler
+ */
 tree
 Intrinsics::compile (TyTy::FnType *fntype)
 {
   rust_assert (fntype->get_abi () == ABI::INTRINSIC);
 
   tree builtin = error_mark_node;
   BuiltinsContext &builtin_ctx = BuiltinsContext::get ();
+
   if (builtin_ctx.lookup_simple_builtin (fntype->get_identifier (), &builtin))
     return builtin;
 
@@ -653,17 +664,17 @@ op_with_overflow_inner (Context *ctx, TyTy::FnType *fntype, tree_code op)
   switch (op)
     {
     case PLUS_EXPR:
-      BuiltinsContext::get ().lookup_simple_builtin ("add_overflow",
+      BuiltinsContext::get ().lookup_simple_builtin ("__builtin_add_overflow",
 						     &overflow_builtin);
       break;
 
     case MINUS_EXPR:
-      BuiltinsContext::get ().lookup_simple_builtin ("sub_overflow",
+      BuiltinsContext::get ().lookup_simple_builtin ("__builtin_sub_overflow",
 						     &overflow_builtin);
       break;
 
     case MULT_EXPR:
-      BuiltinsContext::get ().lookup_simple_builtin ("mul_overflow",
+      BuiltinsContext::get ().lookup_simple_builtin ("__builtin_mul_overflow",
 						     &overflow_builtin);
       break;
 
@@ -749,8 +760,8 @@ copy_handler_inner (Context *ctx, TyTy::FnType *fntype, bool overlaps)
     = build2 (MULT_EXPR, size_type_node, TYPE_SIZE_UNIT (param_type), count);
 
   tree memcpy_raw = nullptr;
-  BuiltinsContext::get ().lookup_simple_builtin (overlaps ? "memmove"
-							  : "memcpy",
+  BuiltinsContext::get ().lookup_simple_builtin (overlaps ? "__builtin_memmove"
+							  : "__builtin_memcpy",
 						 &memcpy_raw);
   rust_assert (memcpy_raw);
   auto memcpy = build_fold_addr_expr_loc (UNKNOWN_LOCATION, memcpy_raw);
@@ -797,18 +808,34 @@ prefetch_data_handler (Context *ctx, TyTy::FnType *fntype, Prefetch kind)
   enter_intrinsic_block (ctx, fndecl);
 
   auto addr = Backend::var_expression (args[0], UNDEF_LOCATION);
-  auto locality = Backend::var_expression (args[1], UNDEF_LOCATION);
+
+  // The core library technically allows you to pass any i32 value as a
+  // locality, but LLVM will then complain if the value cannot be constant
+  // evaluated. For now, we ignore the locality argument and instead always
+  // pass `3` (the most restrictive value). This allows us to still have
+  // prefetch behavior, just not as granular as expected. In future Rust
+  // versions, we hope that prefetch intrinsics will be split up according to
+  // locality, similarly to atomic intrinsics.
+  // The solution is to try and perform constant folding for the locality
+  // argument, or instead of creating a new function definition, modify the call
+  // site directly This has the bad side-effect of creating warnings about
+  // `unused name - locality`, which we hack away here:
+  // TODO: Take care of handling locality properly
+  Backend::var_expression (args[1], UNDEF_LOCATION);
+
   auto rw_flag = make_unsigned_long_tree (kind == Prefetch::Write ? 1 : 0);
 
   auto prefetch_raw = NULL_TREE;
-  auto ok
-    = BuiltinsContext::get ().lookup_simple_builtin ("prefetch", &prefetch_raw);
+  auto ok = BuiltinsContext::get ().lookup_simple_builtin ("__builtin_prefetch",
+							   &prefetch_raw);
   rust_assert (ok);
   auto prefetch = build_fold_addr_expr_loc (UNKNOWN_LOCATION, prefetch_raw);
 
-  auto prefetch_call
-    = Backend::call_expression (prefetch, {addr, rw_flag, locality}, nullptr,
-				UNDEF_LOCATION);
+  auto prefetch_call = Backend::call_expression (prefetch,
+						 {addr, rw_flag,
+						  // locality arg
+						  make_unsigned_long_tree (3)},
+						 nullptr, UNDEF_LOCATION);
 
   TREE_READONLY (prefetch_call) = 0;
   TREE_SIDE_EFFECTS (prefetch_call) = 1;
@@ -833,7 +860,7 @@ build_atomic_builtin_name (const std::string &prefix, location_t locus,
   // TODO: Can we maybe get the generic version (atomic_store_n) to work... This
   // would be so much better
 
-  std::string result = prefix;
+  std::string result = "__" + prefix; //  + "n";
 
   auto type_name = operand_type->get_name ();
   if (type_name == "usize" || type_name == "isize")
@@ -843,6 +870,13 @@ build_atomic_builtin_name (const std::string &prefix, location_t locus,
       return "";
     }
 
+  if (type_name.at (0) == 'i')
+    {
+      rust_sorry_at (locus, "atomics are not yet supported for signed "
+			    "integer types (i8, i16, i32, i64, i128)");
+      return "";
+    }
+
   auto type_size_str = allowed_types.find (type_name);
 
   if (!check_for_basic_integer_type ("atomic", locus, operand_type))
@@ -970,6 +1004,7 @@ atomic_load_handler_inner (Context *ctx, TyTy::FnType *fntype, int ordering)
   TREE_SIDE_EFFECTS (load_call) = 1;
 
   ctx->add_statement (return_statement);
+
   finalize_intrinsic_block (ctx, fndecl);
 
   return fndecl;
@@ -1060,7 +1095,8 @@ uninit_handler (Context *ctx, TyTy::FnType *fntype)
   // BUILTIN size_of FN BODY BEGIN
 
   tree memset_builtin = error_mark_node;
-  BuiltinsContext::get ().lookup_simple_builtin ("memset", &memset_builtin);
+  BuiltinsContext::get ().lookup_simple_builtin ("__builtin_memset",
+						 &memset_builtin);
   rust_assert (memset_builtin != error_mark_node);
 
   // call memset with 0x01 and size of the thing see
@@ -1123,7 +1159,8 @@ move_val_init_handler (Context *ctx, TyTy::FnType *fntype)
   tree size = TYPE_SIZE_UNIT (template_parameter_type);
 
   tree memcpy_builtin = error_mark_node;
-  BuiltinsContext::get ().lookup_simple_builtin ("memcpy", &memcpy_builtin);
+  BuiltinsContext::get ().lookup_simple_builtin ("__builtin_memcpy",
+						 &memcpy_builtin);
   rust_assert (memcpy_builtin != error_mark_node);
 
   src = build_fold_addr_expr_loc (BUILTINS_LOCATION, src);
@@ -1157,7 +1194,8 @@ expect_handler_inner (Context *ctx, TyTy::FnType *fntype, bool likely)
   compile_fn_params (ctx, fntype, fndecl, &param_vars);
   tree expr = Backend::var_expression (param_vars[0], UNDEF_LOCATION);
   tree expect_fn_raw = nullptr;
-  BuiltinsContext::get ().lookup_simple_builtin ("expect", &expect_fn_raw);
+  BuiltinsContext::get ().lookup_simple_builtin ("__builtin_expect",
+						 &expect_fn_raw);
   rust_assert (expect_fn_raw);
   auto expect_fn = build_fold_addr_expr_loc (BUILTINS_LOCATION, expect_fn_raw);