This reimplements the No_Strict_Aliasing configuration pragma, which didn't
work neither for private types nor for access-to-unconstrained-array types.
The following program must compile quietly with -O2:
pragma No_Strict_Aliasing;
with Q; use Q;
package P is
type Ptr is private;
type Arr is array (Natural range <>) of Integer;
type Array_Ptr is access all Arr;
procedure Dummy;
private
type Rec is record
Data : Integer;
end record;
type Ptr is access Rec;
end P;
with Ada.Unchecked_Conversion;
package body P is
function Any_Ptr_To_Map_Ptr is
new Ada.Unchecked_Conversion (Q.T_ANY_PTR, Ptr);
function Any_Array_Ptr_To_Map_Ptr is
new Ada.Unchecked_Conversion (Q.T_ANY_ARRAY_PTR, Array_Ptr);
procedure Dummy is begin null; end;
end P;
package Q is
type T_BYTE is new INTEGER range 0 .. 255;
for T_BYTE'size use 8;
type T_ANY_PTR is access T_BYTE;
type T_BYTE_ARRAY is array (Natural range <>) of T_BYTE;
type T_ANY_ARRAY_PTR is access T_BYTE_ARRAY;
end Q;
Tested on x86_64-pc-linux-gnu, committed on trunk
2015-01-07 Eric Botcazou <ebotca...@adacore.com>
* sem_ch3.adb (Analyze_Full_Type_Declaration): Do not
automatically set No_Strict_Aliasing on access types.
* fe.h (No_Strict_Aliasing_CP): Declare.
* gcc-interface/trans.c (gigi): Force flag_strict_aliasing to 0 if
No_Strict_Aliasing_CP is set.
Index: sem_ch3.adb
===================================================================
--- sem_ch3.adb (revision 219285)
+++ sem_ch3.adb (working copy)
@@ -2657,12 +2657,6 @@
Add_RACW_Features (Def_Id);
end if;
- -- Set no strict aliasing flag if config pragma seen
-
- if Opt.No_Strict_Aliasing then
- Set_No_Strict_Aliasing (Base_Type (Def_Id));
- end if;
-
when N_Array_Type_Definition =>
Array_Type_Declaration (T, Def);
Index: fe.h
===================================================================
--- fe.h (revision 219191)
+++ fe.h (working copy)
@@ -176,6 +176,7 @@
#define Generate_SCO_Instance_Table opt__generate_sco_instance_table
#define GNAT_Mode opt__gnat_mode
#define List_Representation_Info opt__list_representation_info
+#define No_Strict_Aliasing_CP opt__no_strict_aliasing
typedef enum {Setjmp_Longjmp, Back_End_Exceptions} Exception_Mechanism_Type;
@@ -187,6 +188,7 @@
extern Boolean Generate_SCO_Instance_Table;
extern Boolean GNAT_Mode;
extern Int List_Representation_Info;
+extern Boolean No_Strict_Aliasing_CP;
/* restrict: */
Index: gcc-interface/trans.c
===================================================================
--- gcc-interface/trans.c (revision 219286)
+++ gcc-interface/trans.c (working copy)
@@ -667,6 +667,10 @@
/* Initialize the GCC support for FP operations. */
gnat_init_gcc_fp ();
+ /* Force -fno-strict-aliasing if the configuration pragma was seen. */
+ if (No_Strict_Aliasing_CP)
+ flag_strict_aliasing = 0;
+
/* Now translate the compilation unit proper. */
Compilation_Unit_to_gnu (gnat_root);
