d: Compile-time reflection for supported built-ins (PR101127)

In order to allow user-code to determine whether a back-end builtin is
available without error, LANG_HOOKS_BUILTIN_FUNCTION_EXT_SCOPE has been
defined to delay putting back-end builtin functions until the ISA that
defines them has been declared.

However in D, there is no global namespace.  All builtins get pushed
into the `gcc.builtins' module, which is constructed during the semantic
analysis pass, which has already finished by the time target attributes
are evaluated.  So builtins are not pushed by the new langhook because
they would be ultimately ignored.  Builtins exposed to D code then can
now only be altered by the command-line.

	PR d/101127

gcc/d/ChangeLog:

	* d-builtins.cc (d_builtin_function_ext_scope): New function.
	* d-lang.cc (LANG_HOOKS_BUILTIN_FUNCTION_EXT_SCOPE): Define.
	* d-tree.h (d_builtin_function_ext_scope): Declare.

gcc/testsuite/ChangeLog:

	* gdc.dg/pr101127a.d: New test.
	* gdc.dg/pr101127b.d: New test.

diff --git a/gcc/d/d-builtins.cc b/gcc/d/d-builtins.cc
index 859a8ce2a59402afde9a9c44f200703f946ad42e..ff2a5776dc54d5abb3c07f25599be74231a447e4 100644 (file)
--- a/gcc/d/d-builtins.cc
+++ b/gcc/d/d-builtins.cc
@@ -1204,5 +1204,20 @@ d_builtin_function (tree decl)
   return decl;
 }
 
+/* Same as d_builtin_function, but used to delay putting in back-end builtin
+   functions until the ISA that defines the builtin has been declared.
+   However in D, there is no global namespace.  All builtins get pushed into the
+   `gcc.builtins' module, which is constructed during the semantic analysis
+   pass, which has already finished by the time target attributes are evaluated.
+   So builtins are not pushed because they would be ultimately ignored.
+   The purpose of having this function then is to improve compile-time
+   reflection support to allow user-code to determine whether a given back end
+   function is enabled by the ISA.  */
+
+tree
+d_builtin_function_ext_scope (tree decl)
+{
+  return decl;
+}
 
 #include "gt-d-d-builtins.h"

diff --git a/gcc/d/d-lang.cc b/gcc/d/d-lang.cc
index a65af290cb8278f91877f91f6aaedbef910a7fa5..6ad3823d910dcece0a7883708ebbabb14c3b8745 100644 (file)
--- a/gcc/d/d-lang.cc
+++ b/gcc/d/d-lang.cc
@@ -1745,6 +1745,7 @@ d_enum_underlying_base_type (const_tree type)
 #undef LANG_HOOKS_GET_ALIAS_SET
 #undef LANG_HOOKS_TYPES_COMPATIBLE_P
 #undef LANG_HOOKS_BUILTIN_FUNCTION
+#undef LANG_HOOKS_BUILTIN_FUNCTION_EXT_SCOPE
 #undef LANG_HOOKS_REGISTER_BUILTIN_TYPE
 #undef LANG_HOOKS_FINISH_INCOMPLETE_DECL
 #undef LANG_HOOKS_GIMPLIFY_EXPR
@@ -1776,6 +1777,7 @@ d_enum_underlying_base_type (const_tree type)
 #define LANG_HOOKS_GET_ALIAS_SET           d_get_alias_set
 #define LANG_HOOKS_TYPES_COMPATIBLE_P      d_types_compatible_p
 #define LANG_HOOKS_BUILTIN_FUNCTION        d_builtin_function
+#define LANG_HOOKS_BUILTIN_FUNCTION_EXT_SCOPE d_builtin_function_ext_scope
 #define LANG_HOOKS_REGISTER_BUILTIN_TYPE    d_register_builtin_type
 #define LANG_HOOKS_FINISH_INCOMPLETE_DECL   d_finish_incomplete_decl
 #define LANG_HOOKS_GIMPLIFY_EXPR           d_gimplify_expr

diff --git a/gcc/d/d-tree.h b/gcc/d/d-tree.h
index 6ef9af2a991e0269998d3bc8cbdab0ebf6cc7c73..b03d60a5c0e14dee0314ab8cbad476ffefa98c80 100644 (file)
--- a/gcc/d/d-tree.h
+++ b/gcc/d/d-tree.h
@@ -502,6 +502,7 @@ extern const attribute_spec d_langhook_common_attribute_table[];
 extern Type *build_frontend_type (tree);
 
 extern tree d_builtin_function (tree);
+extern tree d_builtin_function_ext_scope (tree);
 extern void d_init_builtins (void);
 extern void d_register_builtin_type (tree, const char *);
 extern void d_build_builtins_module (Module *);

diff --git a/gcc/testsuite/gdc.dg/pr101127a.d b/gcc/testsuite/gdc.dg/pr101127a.d
new file mode 100644 (file)
index 0000000..b56398e
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr101127a.d
@@ -0,0 +1,8 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101127
+// { dg-do compile { target i?86*-*-* x86_64-*-* } }
+// { dg-additional-options "-mavx" }
+
+import gcc.builtins;
+
+static assert(__traits(compiles, __builtin_ia32_andps256));
+static assert(__traits(compiles, __builtin_ia32_pmulhrsw128));

diff --git a/gcc/testsuite/gdc.dg/pr101127b.d b/gcc/testsuite/gdc.dg/pr101127b.d
new file mode 100644 (file)
index 0000000..b462d75
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr101127b.d
@@ -0,0 +1,7 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101127
+// { dg-do compile { target i?86*-*-* x86_64-*-* } }
+
+import gcc.builtins;
+
+static assert(!__traits(compiles, __builtin_ia32_andps256));
+static assert(!__traits(compiles, __builtin_ia32_pmulhrsw128));