From 825da0d20f71cd82fa58e16e92099879e9a8b8f2 Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Wed, 20 Jan 2016 09:01:34 +0000 Subject: exp_ch2.adb (Expand_Current_Value): Make an appropriate character literal if the entity is of a character type. * exp_ch2.adb (Expand_Current_Value): Make an appropriate character literal if the entity is of a character type. * gcc-interface/lang.opt (fsigned-char): New option. * gcc-interface/misc.c (gnat_handle_option): Accept it. (gnat_init): Adjust comment. * gcc-interface/gigi.h (finish_character_type): New prototype. (maybe_character_type): New inline function. (maybe_character_value): Likewise. * gcc-interface/decl.c (gnat_to_gnu_entity) : For a character of CHAR_TYPE_SIZE, make a signed type if flag_signed_char. Set TYPE_ARTIFICIAL early and call finish_character_type on the type. : For a subtype of character with RM_Size and Esize equal to CHAR_TYPE_SIZE, make a signed type if flag_signed_char. Copy TYPE_STRING_FLAG from type to subtype. : Deal with character index types. : Likewise. * gcc-interface/trans.c (gigi): Replace unsigned_char_type_node with char_type_node throughout. (build_raise_check): Likewise. (get_type_length): Deal with character types. (Attribute_to_gnu) : Likewise. Remove obsolete range check code. Minor tweak. : Likewise. (Loop_Statement_to_gnu): Likewise. (Raise_Error_to_gnu): Likewise. : Deal with character index types. Remove obsolete code. : Likewise. : Deal with character types. Minor tweak. : Likewise. : Likewise. : Likewise. (emit_index_check): Delete. * gcc-interface/utils.c (finish_character_type): New function. (gnat_signed_or_unsigned_type_for): Deal with built-in character types. * gcc-interface/utils2.c (expand_sloc): Replace unsigned_char_type_node with char_type_node. (build_call_raise): Likewise. (build_call_raise_column): Likewise. (build_call_raise_range): Likewise. From-SVN: r232604 --- gcc/ada/gcc-interface/utils.c | 45 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'gcc/ada/gcc-interface/utils.c') diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c index 95886f7..0ce571a 100644 --- a/gcc/ada/gcc-interface/utils.c +++ b/gcc/ada/gcc-interface/utils.c @@ -1595,6 +1595,48 @@ record_builtin_type (const char *name, tree type, bool artificial_p) debug_hooks->type_decl (type_decl, false); } +/* Finish constructing the character type CHAR_TYPE. + + In Ada character types are enumeration types and, as a consequence, are + represented in the front-end by integral types holding the positions of + the enumeration values as defined by the language, which means that the + integral types are unsigned. + + Unfortunately the signedness of 'char' in C is implementation-defined + and GCC even has the option -fsigned-char to toggle it at run time. + Since GNAT's philosophy is to be compatible with C by default, to wit + Interfaces.C.char is defined as a mere copy of Character, we may need + to declare character types as signed types in GENERIC and generate the + necessary adjustments to make them behave as unsigned types. + + The overall strategy is as follows: if 'char' is unsigned, do nothing; + if 'char' is signed, translate character types of CHAR_TYPE_SIZE and + character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed + types. The idea is to ensure that the bit pattern contained in the + Esize'd objects is not changed, even though the numerical value will + be interpreted differently depending on the signedness. + + For character types, the bounds are implicit and, therefore, need to + be adjusted. Morever, the debug info needs the unsigned version. */ + +void +finish_character_type (tree char_type) +{ + if (TYPE_UNSIGNED (char_type)) + return; + + /* Make a copy of the unsigned version since we'll modify it below. */ + tree unsigned_char_type = copy_type (gnat_unsigned_type_for (char_type)); + + TYPE_NAME (unsigned_char_type) = TYPE_NAME (char_type); + TYPE_STRING_FLAG (unsigned_char_type) = TYPE_STRING_FLAG (char_type); + TYPE_ARTIFICIAL (unsigned_char_type) = TYPE_ARTIFICIAL (char_type); + + SET_TYPE_DEBUG_TYPE (char_type, unsigned_char_type); + SET_TYPE_RM_MIN_VALUE (char_type, TYPE_MIN_VALUE (unsigned_char_type)); + SET_TYPE_RM_MAX_VALUE (char_type, TYPE_MAX_VALUE (unsigned_char_type)); +} + /* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST, finish constructing the record type as a fat pointer type. */ @@ -3360,6 +3402,9 @@ gnat_type_for_mode (machine_mode mode, int unsignedp) tree gnat_signed_or_unsigned_type_for (int unsignedp, tree type_node) { + if (type_node == char_type_node) + return unsignedp ? unsigned_char_type_node : signed_char_type_node; + tree type = gnat_type_for_size (TYPE_PRECISION (type_node), unsignedp); if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node)) -- cgit v1.1