On 3 November 2013 10:20, Johannes Pfau <nos...@example.com> wrote: > Am Sun, 3 Nov 2013 02:10:20 +0000 > schrieb Iain Buclaw <ibuc...@ubuntu.com>: > > > last time I > > checked, returning 0 disables aliasing rules from taking effect. > > That should work. Alias set 0 is a special alias set which conflicts > with everything. I'll check if it works as expected. >
This is taken from hunks in the 2.064 merge I'm testing: Pastebin link here: http://pastebin.com/jxQQL68N diff --git a/gcc/d/d-lang.cc b/gcc/d/d-lang.cc index 8cba369..a19a59b 100644 --- a/gcc/d/d-lang.cc +++ b/gcc/d/d-lang.cc @@ -73,6 +73,7 @@ const attribute_spec d_attribute_table[] = #undef LANG_HOOKS_COMMON_ATTRIBUTE_TABLE #undef LANG_HOOKS_ATTRIBUTE_TABLE #undef LANG_HOOKS_FORMAT_ATTRIBUTE_TABLE +#undef LANG_HOOKS_GET_ALIAS_SET #undef LANG_HOOKS_TYPES_COMPATIBLE_P #undef LANG_HOOKS_BUILTIN_FUNCTION #undef LANG_HOOKS_BUILTIN_FUNCTION_EXT_SCOPE @@ -95,6 +96,7 @@ const attribute_spec d_attribute_table[] = #define LANG_HOOKS_COMMON_ATTRIBUTE_TABLE d_builtins_attribute_table #define LANG_HOOKS_ATTRIBUTE_TABLE d_attribute_table #define LANG_HOOKS_FORMAT_ATTRIBUTE_TABLE d_format_attribute_table +#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 @@ -1505,6 +1523,33 @@ d_getdecls (void) } +// Get the alias set corresponding to a type or expression. +// Return -1 if we don't do anything special. + +static alias_set_type +d_get_alias_set (tree t) +{ + if (!TYPE_P (t)) + return get_alias_set (TREE_TYPE (t)); + + Type *dtype = build_dtype (t); + + // If the type is a dynamic array, use the alias set of the basetype. + if (dtype && dtype->ty == Tarray) + return get_alias_set (dtype->nextOf()->toCtype()); + + // Permit type-punning when accessing a union, provided the access + // is directly through the union. + for (tree u = t; handled_component_p (u); u = TREE_OPERAND (u, 0)) + { + if (TREE_CODE (u) == COMPONENT_REF + && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE) + return 0; + } + + return -1; +} + static int d_types_compatible_p (tree t1, tree t2) { -- Iain Buclaw *(p < e ? p++ : p) = (c & 0x0f) + '0';
