1-- CC50001.A 2-- 3-- Grant of Unlimited Rights 4-- 5-- Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687, 6-- F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained 7-- unlimited rights in the software and documentation contained herein. 8-- Unlimited rights are defined in DFAR 252.227-7013(a)(19). By making 9-- this public release, the Government intends to confer upon all 10-- recipients unlimited rights equal to those held by the Government. 11-- These rights include rights to use, duplicate, release or disclose the 12-- released technical data and computer software in whole or in part, in 13-- any manner and for any purpose whatsoever, and to have or permit others 14-- to do so. 15-- 16-- DISCLAIMER 17-- 18-- ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR 19-- DISCLOSED ARE AS IS. THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED 20-- WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE 21-- SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE 22-- OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A 23-- PARTICULAR PURPOSE OF SAID MATERIAL. 24--* 25-- 26-- OBJECTIVE: 27-- Check that, in an instance, each implicit declaration of a predefined 28-- operator of a formal tagged private type declares a view of the 29-- corresponding predefined operator of the actual type (even if the 30-- operator has been overridden for the actual type). Check that the 31-- body executed is determined by the type and tag of the operands. 32-- 33-- TEST DESCRIPTION: 34-- The formal tagged private type has an unknown discriminant part, and 35-- is thus indefinite. This allows both definite and indefinite types 36-- to be passed as actuals. For tagged types, definite implies 37-- nondiscriminated, and indefinite implies discriminated (with known 38-- or unknown discriminants). 39-- 40-- Only nonlimited tagged types are tested, since equality operators 41-- are not predefined for limited types. 42-- 43-- A tagged type is passed as an actual to a generic formal tagged 44-- private type. The tagged type overrides the predefined equality 45-- operator. A subprogram within the generic calls the equality operator 46-- of the formal type. In an instance, the equality operator denotes 47-- a view of the predefined operator of the actual type, but the 48-- call dispatches to the body of the overriding operator. 49-- 50-- 51-- CHANGE HISTORY: 52-- 06 Dec 94 SAIC ACVC 2.0 53-- 21 Nov 95 SAIC ACVC 2.0.1 fixes: Corrected expected result on 54-- calls to "=" within the instance. Modified 55-- commentary. 56-- 57--! 58 59package CC50001_0 is 60 61 type Count_Type is tagged record -- Nondiscriminated 62 Count : Integer := 0; -- tagged type. 63 end record; 64 65 function "="(Left, Right : Count_Type) -- User-defined 66 return Boolean; -- equality operator. 67 68 69 subtype Str_Len is Natural range 0 .. 100; 70 subtype Stu_ID is String (1 .. 5); 71 subtype Dept_ID is String (1 .. 4); 72 subtype Emp_ID is String (1 .. 9); 73 type Status is (Student, Faculty, Staff); 74 75 type Person_Type (Stat : Status; -- Discriminated 76 NameLen, AddrLen : Str_Len) is -- tagged type. 77 tagged record 78 Name : String (1 .. NameLen); 79 Address : String (1 .. AddrLen); 80 case Stat is 81 when Student => 82 Student_ID : Stu_ID; 83 when Faculty => 84 Department : Dept_ID; 85 when Staff => 86 Employee_ID : Emp_ID; 87 end case; 88 end record; 89 90 function "="(Left, Right : Person_Type) -- User-defined 91 return Boolean; -- equality operator. 92 93 94 -- Testing entities: ------------------------------------------------ 95 96 TC_Count_Item : constant Count_Type := (Count => 111); 97 98 TC_Person_Item : constant Person_Type := 99 (Faculty, 18, 17, "Eccles, John Scott", "Popham House, Lee", "0931"); 100 101 --------------------------------------------------------------------- 102 103 104end CC50001_0; 105 106 107 --===================================================================-- 108 109 110package body CC50001_0 is 111 112 function "="(Left, Right : Count_Type) return Boolean is 113 begin 114 return False; -- Return FALSE even if Left = Right. 115 end "="; 116 117 118 function "="(Left, Right : Person_Type) return Boolean is 119 begin 120 return False; -- Return FALSE even if Left = Right. 121 end "="; 122 123end CC50001_0; 124 125 126 --===================================================================-- 127 128 129with CC50001_0; -- Tagged (actual) type declarations. 130generic -- Generic stack abstraction. 131 132 type Item (<>) is tagged private; -- Formal tagged private type. 133 134package CC50001_1 is 135 136 -- Simulate a generic stack abstraction. In a real application, the 137 -- second operand of Push might be of type Stack, and type Stack 138 -- would have at least one component (pointing to the top stack item). 139 140 type Stack is private; 141 142 procedure Push (I : in Item; TC_Check : out Boolean); 143 144 -- ... Other stack operations. 145 146private 147 148 -- ... Stack and ancillary type declarations. 149 150 type Stack is record -- Artificial. 151 null; 152 end record; 153 154end CC50001_1; 155 156 157 --===================================================================-- 158 159 160package body CC50001_1 is 161 162 -- For the sake of brevity, the implementation of Push is completely 163 -- artificial; the goal is to model a call of the equality operator within 164 -- the generic. 165 -- 166 -- A real application might implement Push such that it does not add new 167 -- items to the stack if they are identical to the top item; in that 168 -- case, the equality operator would be called as part of an "if" 169 -- condition. 170 171 procedure Push (I : in Item; TC_Check : out Boolean) is 172 begin 173 TC_Check := not (I = I); -- Call user-defined "="; should 174 -- return FALSE. Negation of 175 -- result makes TC_Check TRUE. 176 end Push; 177 178end CC50001_1; 179 180 181 --==================================================================-- 182 183 184with CC50001_0; -- Tagged (actual) type declarations. 185with CC50001_1; -- Generic stack abstraction. 186 187use CC50001_0; -- Overloaded "=" directly visible. 188 189with Report; 190procedure CC50001 is 191 192 package Count_Stacks is new CC50001_1 (CC50001_0.Count_Type); 193 package Person_Stacks is new CC50001_1 (CC50001_0.Person_Type); 194 195 User_Defined_Op_Called : Boolean; 196 197begin 198 Report.Test ("CC50001", "Check that, in an instance, each implicit " & 199 "declaration of a primitive subprogram of a formal tagged " & 200 "private type declares a view of the corresponding " & 201 "predefined operator of the actual type (even if the " & 202 "operator has been overridden or hidden for the actual type)"); 203 204-- 205-- Test which "=" is called inside generic: 206-- 207 208 User_Defined_Op_Called := False; 209 210 Count_Stacks.Push (CC50001_0.TC_Count_Item, 211 User_Defined_Op_Called); 212 213 214 if not User_Defined_Op_Called then 215 Report.Failed ("User-defined ""="" not called inside generic for Count"); 216 end if; 217 218 219 User_Defined_Op_Called := False; 220 221 Person_Stacks.Push (CC50001_0.TC_Person_Item, 222 User_Defined_Op_Called); 223 224 if not User_Defined_Op_Called then 225 Report.Failed ("User-defined ""="" not called inside generic " & 226 "for Person"); 227 end if; 228 229 230-- 231-- Test which "=" is called outside generic: 232-- 233 234 User_Defined_Op_Called := False; 235 236 User_Defined_Op_Called := 237 not (CC50001_0.TC_Count_Item = CC50001_0.TC_Count_Item); 238 239 if not User_Defined_Op_Called then 240 Report.Failed ("User-defined ""="" not called outside generic "& 241 "for Count"); 242 end if; 243 244 245 User_Defined_Op_Called := False; 246 247 User_Defined_Op_Called := 248 not (CC50001_0.TC_Person_Item = CC50001_0.TC_Person_Item); 249 250 if not User_Defined_Op_Called then 251 Report.Failed ("User-defined ""="" not called outside generic "& 252 "for Person"); 253 end if; 254 255 256 Report.Result; 257end CC50001; 258