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1 ------------------------------------------------------------------------------
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2 -- --
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3 -- GNAT COMPILER COMPONENTS --
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4 -- --
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5 -- S E M _ D I S P --
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6 -- --
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7 -- B o d y --
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8 -- --
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131
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9 -- Copyright (C) 1992-2018, Free Software Foundation, Inc. --
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111
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10 -- --
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11 -- GNAT is free software; you can redistribute it and/or modify it under --
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12 -- terms of the GNU General Public License as published by the Free Soft- --
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13 -- ware Foundation; either version 3, or (at your option) any later ver- --
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14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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17 -- for more details. You should have received a copy of the GNU General --
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18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
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19 -- http://www.gnu.org/licenses for a complete copy of the license. --
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20 -- --
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21 -- GNAT was originally developed by the GNAT team at New York University. --
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22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
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23 -- --
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24 ------------------------------------------------------------------------------
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25
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26 with Atree; use Atree;
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27 with Debug; use Debug;
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28 with Elists; use Elists;
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29 with Einfo; use Einfo;
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30 with Exp_Disp; use Exp_Disp;
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31 with Exp_Util; use Exp_Util;
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32 with Exp_Ch7; use Exp_Ch7;
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33 with Exp_Tss; use Exp_Tss;
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34 with Errout; use Errout;
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35 with Lib.Xref; use Lib.Xref;
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36 with Namet; use Namet;
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37 with Nlists; use Nlists;
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38 with Nmake; use Nmake;
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39 with Opt; use Opt;
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40 with Output; use Output;
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41 with Restrict; use Restrict;
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42 with Rident; use Rident;
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43 with Sem; use Sem;
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44 with Sem_Aux; use Sem_Aux;
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45 with Sem_Ch3; use Sem_Ch3;
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46 with Sem_Ch6; use Sem_Ch6;
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47 with Sem_Ch8; use Sem_Ch8;
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48 with Sem_Eval; use Sem_Eval;
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49 with Sem_Type; use Sem_Type;
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50 with Sem_Util; use Sem_Util;
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51 with Snames; use Snames;
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52 with Sinfo; use Sinfo;
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53 with Tbuild; use Tbuild;
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54 with Uintp; use Uintp;
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55 with Warnsw; use Warnsw;
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56
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57 package body Sem_Disp is
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58
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59 -----------------------
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60 -- Local Subprograms --
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61 -----------------------
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62
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63 procedure Add_Dispatching_Operation
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64 (Tagged_Type : Entity_Id;
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65 New_Op : Entity_Id);
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66 -- Add New_Op in the list of primitive operations of Tagged_Type
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67
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68 function Check_Controlling_Type
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69 (T : Entity_Id;
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70 Subp : Entity_Id) return Entity_Id;
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71 -- T is the tagged type of a formal parameter or the result of Subp.
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72 -- If the subprogram has a controlling parameter or result that matches
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73 -- the type, then returns the tagged type of that parameter or result
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74 -- (returning the designated tagged type in the case of an access
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75 -- parameter); otherwise returns empty.
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76
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77 function Find_Hidden_Overridden_Primitive (S : Entity_Id) return Entity_Id;
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78 -- [Ada 2012:AI-0125] Find an inherited hidden primitive of the dispatching
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79 -- type of S that has the same name of S, a type-conformant profile, an
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80 -- original corresponding operation O that is a primitive of a visible
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81 -- ancestor of the dispatching type of S and O is visible at the point of
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82 -- of declaration of S. If the entity is found the Alias of S is set to the
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83 -- original corresponding operation S and its Overridden_Operation is set
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84 -- to the found entity; otherwise return Empty.
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85 --
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86 -- This routine does not search for non-hidden primitives since they are
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87 -- covered by the normal Ada 2005 rules.
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88
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89 function Is_Inherited_Public_Operation (Op : Entity_Id) return Boolean;
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90 -- Check whether a primitive operation is inherited from an operation
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91 -- declared in the visible part of its package.
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92
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93 -------------------------------
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94 -- Add_Dispatching_Operation --
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95 -------------------------------
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96
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97 procedure Add_Dispatching_Operation
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98 (Tagged_Type : Entity_Id;
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99 New_Op : Entity_Id)
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100 is
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101 List : constant Elist_Id := Primitive_Operations (Tagged_Type);
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102
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103 begin
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104 -- The dispatching operation may already be on the list, if it is the
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105 -- wrapper for an inherited function of a null extension (see Exp_Ch3
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106 -- for the construction of function wrappers). The list of primitive
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107 -- operations must not contain duplicates.
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108
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131
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109 -- The Default_Initial_Condition and invariant procedures are not added
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110 -- to the list of primitives even when they are generated for a tagged
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111 -- type. These routines must not be targets of dispatching calls and
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112 -- therefore must not appear in the dispatch table because they already
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113 -- utilize class-wide-precondition semantics to handle inheritance and
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114 -- overriding.
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115
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116 if Is_Suitable_Primitive (New_Op) then
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117 Append_Unique_Elmt (New_Op, List);
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118 end if;
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111
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119 end Add_Dispatching_Operation;
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120
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121 --------------------------
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122 -- Covered_Interface_Op --
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123 --------------------------
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124
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125 function Covered_Interface_Op (Prim : Entity_Id) return Entity_Id is
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126 Tagged_Type : constant Entity_Id := Find_Dispatching_Type (Prim);
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127 Elmt : Elmt_Id;
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128 E : Entity_Id;
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129
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130 begin
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131 pragma Assert (Is_Dispatching_Operation (Prim));
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132
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133 -- Although this is a dispatching primitive we must check if its
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134 -- dispatching type is available because it may be the primitive
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135 -- of a private type not defined as tagged in its partial view.
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136
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137 if Present (Tagged_Type) and then Has_Interfaces (Tagged_Type) then
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138
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139 -- If the tagged type is frozen then the internal entities associated
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140 -- with interfaces are available in the list of primitives of the
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141 -- tagged type and can be used to speed up this search.
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142
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143 if Is_Frozen (Tagged_Type) then
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144 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
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145 while Present (Elmt) loop
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146 E := Node (Elmt);
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147
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148 if Present (Interface_Alias (E))
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149 and then Alias (E) = Prim
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150 then
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151 return Interface_Alias (E);
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152 end if;
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153
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154 Next_Elmt (Elmt);
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155 end loop;
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156
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157 -- Otherwise we must collect all the interface primitives and check
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158 -- if the Prim overrides (implements) some interface primitive.
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159
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160 else
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161 declare
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162 Ifaces_List : Elist_Id;
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163 Iface_Elmt : Elmt_Id;
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164 Iface : Entity_Id;
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165 Iface_Prim : Entity_Id;
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166
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167 begin
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168 Collect_Interfaces (Tagged_Type, Ifaces_List);
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169 Iface_Elmt := First_Elmt (Ifaces_List);
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170 while Present (Iface_Elmt) loop
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171 Iface := Node (Iface_Elmt);
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172
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173 Elmt := First_Elmt (Primitive_Operations (Iface));
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174 while Present (Elmt) loop
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175 Iface_Prim := Node (Elmt);
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176
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177 if Chars (Iface_Prim) = Chars (Prim)
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178 and then Is_Interface_Conformant
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179 (Tagged_Type, Iface_Prim, Prim)
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180 then
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181 return Iface_Prim;
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182 end if;
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183
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184 Next_Elmt (Elmt);
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185 end loop;
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186
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187 Next_Elmt (Iface_Elmt);
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188 end loop;
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189 end;
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190 end if;
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191 end if;
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192
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193 return Empty;
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194 end Covered_Interface_Op;
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195
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196 -------------------------------
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197 -- Check_Controlling_Formals --
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198 -------------------------------
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199
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200 procedure Check_Controlling_Formals
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201 (Typ : Entity_Id;
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202 Subp : Entity_Id)
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203 is
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204 Formal : Entity_Id;
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205 Ctrl_Type : Entity_Id;
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206
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207 begin
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208 Formal := First_Formal (Subp);
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209 while Present (Formal) loop
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210 Ctrl_Type := Check_Controlling_Type (Etype (Formal), Subp);
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211
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212 if Present (Ctrl_Type) then
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213
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214 -- When controlling type is concurrent and declared within a
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215 -- generic or inside an instance use corresponding record type.
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216
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217 if Is_Concurrent_Type (Ctrl_Type)
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218 and then Present (Corresponding_Record_Type (Ctrl_Type))
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219 then
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220 Ctrl_Type := Corresponding_Record_Type (Ctrl_Type);
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221 end if;
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222
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223 if Ctrl_Type = Typ then
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224 Set_Is_Controlling_Formal (Formal);
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225
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226 -- Ada 2005 (AI-231): Anonymous access types that are used in
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227 -- controlling parameters exclude null because it is necessary
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228 -- to read the tag to dispatch, and null has no tag.
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229
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230 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
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231 Set_Can_Never_Be_Null (Etype (Formal));
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232 Set_Is_Known_Non_Null (Etype (Formal));
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233 end if;
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234
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235 -- Check that the parameter's nominal subtype statically
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236 -- matches the first subtype.
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237
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238 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
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239 if not Subtypes_Statically_Match
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240 (Typ, Designated_Type (Etype (Formal)))
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241 then
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242 Error_Msg_N
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243 ("parameter subtype does not match controlling type",
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244 Formal);
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245 end if;
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246
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247 -- Within a predicate function, the formal may be a subtype
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248 -- of a tagged type, given that the predicate is expressed
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249 -- in terms of the subtype.
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250
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251 elsif not Subtypes_Statically_Match (Typ, Etype (Formal))
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252 and then not Is_Predicate_Function (Subp)
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253 then
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254 Error_Msg_N
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255 ("parameter subtype does not match controlling type",
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256 Formal);
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257 end if;
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258
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259 if Present (Default_Value (Formal)) then
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260
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261 -- In Ada 2005, access parameters can have defaults
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262
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263 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
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264 and then Ada_Version < Ada_2005
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265 then
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266 Error_Msg_N
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267 ("default not allowed for controlling access parameter",
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268 Default_Value (Formal));
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269
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270 elsif not Is_Tag_Indeterminate (Default_Value (Formal)) then
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271 Error_Msg_N
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272 ("default expression must be a tag indeterminate" &
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273 " function call", Default_Value (Formal));
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274 end if;
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275 end if;
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276
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277 elsif Comes_From_Source (Subp) then
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278 Error_Msg_N
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279 ("operation can be dispatching in only one type", Subp);
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280 end if;
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281 end if;
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282
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283 Next_Formal (Formal);
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284 end loop;
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285
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286 if Ekind_In (Subp, E_Function, E_Generic_Function) then
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287 Ctrl_Type := Check_Controlling_Type (Etype (Subp), Subp);
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288
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289 if Present (Ctrl_Type) then
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290 if Ctrl_Type = Typ then
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291 Set_Has_Controlling_Result (Subp);
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292
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293 -- Check that result subtype statically matches first subtype
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294 -- (Ada 2005): Subp may have a controlling access result.
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295
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296 if Subtypes_Statically_Match (Typ, Etype (Subp))
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297 or else (Ekind (Etype (Subp)) = E_Anonymous_Access_Type
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298 and then
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299 Subtypes_Statically_Match
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300 (Typ, Designated_Type (Etype (Subp))))
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301 then
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302 null;
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303
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304 else
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305 Error_Msg_N
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306 ("result subtype does not match controlling type", Subp);
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307 end if;
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308
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309 elsif Comes_From_Source (Subp) then
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310 Error_Msg_N
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311 ("operation can be dispatching in only one type", Subp);
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312 end if;
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313 end if;
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314 end if;
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315 end Check_Controlling_Formals;
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316
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317 ----------------------------
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318 -- Check_Controlling_Type --
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319 ----------------------------
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320
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321 function Check_Controlling_Type
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322 (T : Entity_Id;
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323 Subp : Entity_Id) return Entity_Id
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324 is
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325 Tagged_Type : Entity_Id := Empty;
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326
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327 begin
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328 if Is_Tagged_Type (T) then
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329 if Is_First_Subtype (T) then
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330 Tagged_Type := T;
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331 else
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332 Tagged_Type := Base_Type (T);
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333 end if;
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334
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335 -- If the type is incomplete, it may have been declared without a
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336 -- Tagged indication, but the full view may be tagged, in which case
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337 -- that is the controlling type of the subprogram. This is one of the
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338 -- approx. 579 places in the language where a lookahead would help.
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339
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340 elsif Ekind (T) = E_Incomplete_Type
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341 and then Present (Full_View (T))
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342 and then Is_Tagged_Type (Full_View (T))
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343 then
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344 Set_Is_Tagged_Type (T);
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345 Tagged_Type := Full_View (T);
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346
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347 elsif Ekind (T) = E_Anonymous_Access_Type
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348 and then Is_Tagged_Type (Designated_Type (T))
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349 then
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350 if Ekind (Designated_Type (T)) /= E_Incomplete_Type then
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351 if Is_First_Subtype (Designated_Type (T)) then
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352 Tagged_Type := Designated_Type (T);
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353 else
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354 Tagged_Type := Base_Type (Designated_Type (T));
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355 end if;
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356
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357 -- Ada 2005: an incomplete type can be tagged. An operation with an
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358 -- access parameter of the type is dispatching.
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359
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360 elsif Scope (Designated_Type (T)) = Current_Scope then
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361 Tagged_Type := Designated_Type (T);
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362
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363 -- Ada 2005 (AI-50217)
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364
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365 elsif From_Limited_With (Designated_Type (T))
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366 and then Has_Non_Limited_View (Designated_Type (T))
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367 and then Scope (Designated_Type (T)) = Scope (Subp)
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368 then
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369 if Is_First_Subtype (Non_Limited_View (Designated_Type (T))) then
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370 Tagged_Type := Non_Limited_View (Designated_Type (T));
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371 else
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372 Tagged_Type := Base_Type (Non_Limited_View
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373 (Designated_Type (T)));
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374 end if;
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375 end if;
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376 end if;
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377
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378 if No (Tagged_Type) or else Is_Class_Wide_Type (Tagged_Type) then
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379 return Empty;
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380
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381 -- The dispatching type and the primitive operation must be defined in
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382 -- the same scope, except in the case of internal operations and formal
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383 -- abstract subprograms.
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384
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385 elsif ((Scope (Subp) = Scope (Tagged_Type) or else Is_Internal (Subp))
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386 and then (not Is_Generic_Type (Tagged_Type)
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387 or else not Comes_From_Source (Subp)))
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388 or else
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389 (Is_Formal_Subprogram (Subp) and then Is_Abstract_Subprogram (Subp))
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390 or else
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391 (Nkind (Parent (Parent (Subp))) = N_Subprogram_Renaming_Declaration
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392 and then
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393 Present (Corresponding_Formal_Spec (Parent (Parent (Subp))))
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394 and then
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395 Is_Abstract_Subprogram (Subp))
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396 then
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397 return Tagged_Type;
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398
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399 else
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400 return Empty;
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401 end if;
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402 end Check_Controlling_Type;
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403
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404 ----------------------------
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405 -- Check_Dispatching_Call --
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406 ----------------------------
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407
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408 procedure Check_Dispatching_Call (N : Node_Id) is
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409 Loc : constant Source_Ptr := Sloc (N);
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410 Actual : Node_Id;
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411 Formal : Entity_Id;
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412 Control : Node_Id := Empty;
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|
413 Func : Entity_Id;
|
|
|
414 Subp_Entity : Entity_Id;
|
|
|
415 Indeterm_Ancestor_Call : Boolean := False;
|
|
131
|
416 Indeterm_Ctrl_Type : Entity_Id := Empty; -- init to avoid warning
|
|
111
|
417
|
|
|
418 Static_Tag : Node_Id := Empty;
|
|
|
419 -- If a controlling formal has a statically tagged actual, the tag of
|
|
|
420 -- this actual is to be used for any tag-indeterminate actual.
|
|
|
421
|
|
|
422 procedure Check_Direct_Call;
|
|
|
423 -- In the case when the controlling actual is a class-wide type whose
|
|
|
424 -- root type's completion is a task or protected type, the call is in
|
|
|
425 -- fact direct. This routine detects the above case and modifies the
|
|
|
426 -- call accordingly.
|
|
|
427
|
|
|
428 procedure Check_Dispatching_Context (Call : Node_Id);
|
|
|
429 -- If the call is tag-indeterminate and the entity being called is
|
|
|
430 -- abstract, verify that the context is a call that will eventually
|
|
|
431 -- provide a tag for dispatching, or has provided one already.
|
|
|
432
|
|
|
433 -----------------------
|
|
|
434 -- Check_Direct_Call --
|
|
|
435 -----------------------
|
|
|
436
|
|
|
437 procedure Check_Direct_Call is
|
|
|
438 Typ : Entity_Id := Etype (Control);
|
|
|
439 begin
|
|
|
440 -- Predefined primitives do not receive wrappers since they are built
|
|
|
441 -- from scratch for the corresponding record of synchronized types.
|
|
|
442 -- Equality is in general predefined, but is excluded from the check
|
|
|
443 -- when it is user-defined.
|
|
|
444
|
|
|
445 if Is_Predefined_Dispatching_Operation (Subp_Entity)
|
|
|
446 and then not Is_User_Defined_Equality (Subp_Entity)
|
|
|
447 then
|
|
|
448 return;
|
|
|
449 end if;
|
|
|
450
|
|
|
451 if Is_Class_Wide_Type (Typ) then
|
|
|
452 Typ := Root_Type (Typ);
|
|
|
453 end if;
|
|
|
454
|
|
|
455 if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then
|
|
|
456 Typ := Full_View (Typ);
|
|
|
457 end if;
|
|
|
458
|
|
|
459 if Is_Concurrent_Type (Typ)
|
|
|
460 and then
|
|
|
461 Present (Corresponding_Record_Type (Typ))
|
|
|
462 then
|
|
|
463 Typ := Corresponding_Record_Type (Typ);
|
|
|
464
|
|
|
465 -- The concurrent record's list of primitives should contain a
|
|
|
466 -- wrapper for the entity of the call, retrieve it.
|
|
|
467
|
|
|
468 declare
|
|
|
469 Prim : Entity_Id;
|
|
|
470 Prim_Elmt : Elmt_Id;
|
|
|
471 Wrapper_Found : Boolean := False;
|
|
|
472
|
|
|
473 begin
|
|
|
474 Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
|
|
|
475 while Present (Prim_Elmt) loop
|
|
|
476 Prim := Node (Prim_Elmt);
|
|
|
477
|
|
|
478 if Is_Primitive_Wrapper (Prim)
|
|
|
479 and then Wrapped_Entity (Prim) = Subp_Entity
|
|
|
480 then
|
|
|
481 Wrapper_Found := True;
|
|
|
482 exit;
|
|
|
483 end if;
|
|
|
484
|
|
|
485 Next_Elmt (Prim_Elmt);
|
|
|
486 end loop;
|
|
|
487
|
|
|
488 -- A primitive declared between two views should have a
|
|
|
489 -- corresponding wrapper.
|
|
|
490
|
|
|
491 pragma Assert (Wrapper_Found);
|
|
|
492
|
|
|
493 -- Modify the call by setting the proper entity
|
|
|
494
|
|
|
495 Set_Entity (Name (N), Prim);
|
|
|
496 end;
|
|
|
497 end if;
|
|
|
498 end Check_Direct_Call;
|
|
|
499
|
|
|
500 -------------------------------
|
|
|
501 -- Check_Dispatching_Context --
|
|
|
502 -------------------------------
|
|
|
503
|
|
|
504 procedure Check_Dispatching_Context (Call : Node_Id) is
|
|
|
505 Subp : constant Entity_Id := Entity (Name (Call));
|
|
|
506
|
|
|
507 procedure Abstract_Context_Error;
|
|
|
508 -- Error for abstract call dispatching on result is not dispatching
|
|
|
509
|
|
|
510 ----------------------------
|
|
|
511 -- Abstract_Context_Error --
|
|
|
512 ----------------------------
|
|
|
513
|
|
|
514 procedure Abstract_Context_Error is
|
|
|
515 begin
|
|
|
516 if Ekind (Subp) = E_Function then
|
|
|
517 Error_Msg_N
|
|
|
518 ("call to abstract function must be dispatching", N);
|
|
|
519
|
|
|
520 -- This error can occur for a procedure in the case of a call to
|
|
|
521 -- an abstract formal procedure with a statically tagged operand.
|
|
|
522
|
|
|
523 else
|
|
|
524 Error_Msg_N
|
|
|
525 ("call to abstract procedure must be dispatching", N);
|
|
|
526 end if;
|
|
|
527 end Abstract_Context_Error;
|
|
|
528
|
|
|
529 -- Local variables
|
|
|
530
|
|
|
531 Scop : constant Entity_Id := Current_Scope_No_Loops;
|
|
|
532 Typ : constant Entity_Id := Etype (Subp);
|
|
|
533 Par : Node_Id;
|
|
|
534
|
|
|
535 -- Start of processing for Check_Dispatching_Context
|
|
|
536
|
|
|
537 begin
|
|
|
538 -- If the called subprogram is a private overriding, replace it
|
|
|
539 -- with its alias, which has the correct body. Verify that the
|
|
|
540 -- two subprograms have the same controlling type (this is not the
|
|
|
541 -- case for an inherited subprogram that has become abstract).
|
|
|
542
|
|
|
543 if Is_Abstract_Subprogram (Subp)
|
|
|
544 and then No (Controlling_Argument (Call))
|
|
|
545 then
|
|
|
546 if Present (Alias (Subp))
|
|
|
547 and then not Is_Abstract_Subprogram (Alias (Subp))
|
|
|
548 and then No (DTC_Entity (Subp))
|
|
|
549 and then Find_Dispatching_Type (Subp) =
|
|
|
550 Find_Dispatching_Type (Alias (Subp))
|
|
|
551 then
|
|
|
552 -- Private overriding of inherited abstract operation, call is
|
|
|
553 -- legal.
|
|
|
554
|
|
|
555 Set_Entity (Name (N), Alias (Subp));
|
|
|
556 return;
|
|
|
557
|
|
|
558 -- An obscure special case: a null procedure may have a class-
|
|
|
559 -- wide pre/postcondition that includes a call to an abstract
|
|
|
560 -- subp. Calls within the expression may not have been rewritten
|
|
|
561 -- as dispatching calls yet, because the null body appears in
|
|
|
562 -- the current declarative part. The expression will be properly
|
|
|
563 -- rewritten/reanalyzed when the postcondition procedure is built.
|
|
|
564
|
|
|
565 -- Similarly, if this is a pre/postcondition for an abstract
|
|
|
566 -- subprogram, it may call another abstract function which is
|
|
|
567 -- a primitive of an abstract type. The call is non-dispatching
|
|
|
568 -- but will be legal in overridings of the operation.
|
|
|
569
|
|
|
570 elsif (Is_Subprogram (Scop)
|
|
|
571 or else Chars (Scop) = Name_Postcondition)
|
|
|
572 and then
|
|
|
573 (Is_Abstract_Subprogram (Scop)
|
|
|
574 or else
|
|
|
575 (Nkind (Parent (Scop)) = N_Procedure_Specification
|
|
|
576 and then Null_Present (Parent (Scop))))
|
|
|
577 then
|
|
|
578 null;
|
|
|
579
|
|
|
580 elsif Ekind (Current_Scope) = E_Function
|
|
|
581 and then Nkind (Unit_Declaration_Node (Scop)) =
|
|
|
582 N_Generic_Subprogram_Declaration
|
|
|
583 then
|
|
|
584 null;
|
|
|
585
|
|
|
586 else
|
|
|
587 -- We need to determine whether the context of the call
|
|
|
588 -- provides a tag to make the call dispatching. This requires
|
|
|
589 -- the call to be the actual in an enclosing call, and that
|
|
|
590 -- actual must be controlling. If the call is an operand of
|
|
|
591 -- equality, the other operand must not ve abstract.
|
|
|
592
|
|
|
593 if not Is_Tagged_Type (Typ)
|
|
|
594 and then not
|
|
|
595 (Ekind (Typ) = E_Anonymous_Access_Type
|
|
|
596 and then Is_Tagged_Type (Designated_Type (Typ)))
|
|
|
597 then
|
|
|
598 Abstract_Context_Error;
|
|
|
599 return;
|
|
|
600 end if;
|
|
|
601
|
|
|
602 Par := Parent (Call);
|
|
|
603
|
|
|
604 if Nkind (Par) = N_Parameter_Association then
|
|
|
605 Par := Parent (Par);
|
|
|
606 end if;
|
|
|
607
|
|
|
608 if Nkind (Par) = N_Qualified_Expression
|
|
|
609 or else Nkind (Par) = N_Unchecked_Type_Conversion
|
|
|
610 then
|
|
|
611 Par := Parent (Par);
|
|
|
612 end if;
|
|
|
613
|
|
|
614 if Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
|
|
|
615 and then Is_Entity_Name (Name (Par))
|
|
|
616 then
|
|
|
617 declare
|
|
|
618 Enc_Subp : constant Entity_Id := Entity (Name (Par));
|
|
|
619 A : Node_Id;
|
|
|
620 F : Entity_Id;
|
|
|
621 Control : Entity_Id;
|
|
|
622 Ret_Type : Entity_Id;
|
|
|
623
|
|
|
624 begin
|
|
|
625 -- Find controlling formal that can provide tag for the
|
|
|
626 -- tag-indeterminate actual. The corresponding actual
|
|
|
627 -- must be the corresponding class-wide type.
|
|
|
628
|
|
|
629 F := First_Formal (Enc_Subp);
|
|
|
630 A := First_Actual (Par);
|
|
|
631
|
|
|
632 -- Find controlling type of call. Dereference if function
|
|
|
633 -- returns an access type.
|
|
|
634
|
|
|
635 Ret_Type := Etype (Call);
|
|
|
636 if Is_Access_Type (Etype (Call)) then
|
|
|
637 Ret_Type := Designated_Type (Ret_Type);
|
|
|
638 end if;
|
|
|
639
|
|
|
640 while Present (F) loop
|
|
|
641 Control := Etype (A);
|
|
|
642
|
|
|
643 if Is_Access_Type (Control) then
|
|
|
644 Control := Designated_Type (Control);
|
|
|
645 end if;
|
|
|
646
|
|
|
647 if Is_Controlling_Formal (F)
|
|
|
648 and then not (Call = A or else Parent (Call) = A)
|
|
|
649 and then Control = Class_Wide_Type (Ret_Type)
|
|
|
650 then
|
|
|
651 return;
|
|
|
652 end if;
|
|
|
653
|
|
|
654 Next_Formal (F);
|
|
|
655 Next_Actual (A);
|
|
|
656 end loop;
|
|
|
657
|
|
|
658 if Nkind (Par) = N_Function_Call
|
|
|
659 and then Is_Tag_Indeterminate (Par)
|
|
|
660 then
|
|
|
661 -- The parent may be an actual of an enclosing call
|
|
|
662
|
|
|
663 Check_Dispatching_Context (Par);
|
|
|
664 return;
|
|
|
665
|
|
|
666 else
|
|
|
667 Error_Msg_N
|
|
|
668 ("call to abstract function must be dispatching",
|
|
|
669 Call);
|
|
|
670 return;
|
|
|
671 end if;
|
|
|
672 end;
|
|
|
673
|
|
|
674 -- For equality operators, one of the operands must be
|
|
|
675 -- statically or dynamically tagged.
|
|
|
676
|
|
|
677 elsif Nkind_In (Par, N_Op_Eq, N_Op_Ne) then
|
|
|
678 if N = Right_Opnd (Par)
|
|
|
679 and then Is_Tag_Indeterminate (Left_Opnd (Par))
|
|
|
680 then
|
|
|
681 Abstract_Context_Error;
|
|
|
682
|
|
|
683 elsif N = Left_Opnd (Par)
|
|
|
684 and then Is_Tag_Indeterminate (Right_Opnd (Par))
|
|
|
685 then
|
|
|
686 Abstract_Context_Error;
|
|
|
687 end if;
|
|
|
688
|
|
|
689 return;
|
|
|
690
|
|
|
691 -- The left-hand side of an assignment provides the tag
|
|
|
692
|
|
|
693 elsif Nkind (Par) = N_Assignment_Statement then
|
|
|
694 return;
|
|
|
695
|
|
|
696 else
|
|
|
697 Abstract_Context_Error;
|
|
|
698 end if;
|
|
|
699 end if;
|
|
|
700 end if;
|
|
|
701 end Check_Dispatching_Context;
|
|
|
702
|
|
|
703 -- Start of processing for Check_Dispatching_Call
|
|
|
704
|
|
|
705 begin
|
|
|
706 -- Find a controlling argument, if any
|
|
|
707
|
|
|
708 if Present (Parameter_Associations (N)) then
|
|
|
709 Subp_Entity := Entity (Name (N));
|
|
|
710
|
|
|
711 Actual := First_Actual (N);
|
|
|
712 Formal := First_Formal (Subp_Entity);
|
|
|
713 while Present (Actual) loop
|
|
|
714 Control := Find_Controlling_Arg (Actual);
|
|
|
715 exit when Present (Control);
|
|
|
716
|
|
|
717 -- Check for the case where the actual is a tag-indeterminate call
|
|
|
718 -- whose result type is different than the tagged type associated
|
|
|
719 -- with the containing call, but is an ancestor of the type.
|
|
|
720
|
|
|
721 if Is_Controlling_Formal (Formal)
|
|
|
722 and then Is_Tag_Indeterminate (Actual)
|
|
|
723 and then Base_Type (Etype (Actual)) /= Base_Type (Etype (Formal))
|
|
|
724 and then Is_Ancestor (Etype (Actual), Etype (Formal))
|
|
|
725 then
|
|
|
726 Indeterm_Ancestor_Call := True;
|
|
|
727 Indeterm_Ctrl_Type := Etype (Formal);
|
|
|
728
|
|
|
729 -- If the formal is controlling but the actual is not, the type
|
|
|
730 -- of the actual is statically known, and may be used as the
|
|
|
731 -- controlling tag for some other tag-indeterminate actual.
|
|
|
732
|
|
|
733 elsif Is_Controlling_Formal (Formal)
|
|
|
734 and then Is_Entity_Name (Actual)
|
|
|
735 and then Is_Tagged_Type (Etype (Actual))
|
|
|
736 then
|
|
|
737 Static_Tag := Actual;
|
|
|
738 end if;
|
|
|
739
|
|
|
740 Next_Actual (Actual);
|
|
|
741 Next_Formal (Formal);
|
|
|
742 end loop;
|
|
|
743
|
|
|
744 -- If the call doesn't have a controlling actual but does have an
|
|
|
745 -- indeterminate actual that requires dispatching treatment, then an
|
|
|
746 -- object is needed that will serve as the controlling argument for
|
|
|
747 -- a dispatching call on the indeterminate actual. This can occur
|
|
|
748 -- in the unusual situation of a default actual given by a tag-
|
|
|
749 -- indeterminate call and where the type of the call is an ancestor
|
|
|
750 -- of the type associated with a containing call to an inherited
|
|
|
751 -- operation (see AI-239).
|
|
|
752
|
|
|
753 -- Rather than create an object of the tagged type, which would
|
|
|
754 -- be problematic for various reasons (default initialization,
|
|
|
755 -- discriminants), the tag of the containing call's associated
|
|
|
756 -- tagged type is directly used to control the dispatching.
|
|
|
757
|
|
|
758 if No (Control)
|
|
|
759 and then Indeterm_Ancestor_Call
|
|
|
760 and then No (Static_Tag)
|
|
|
761 then
|
|
|
762 Control :=
|
|
|
763 Make_Attribute_Reference (Loc,
|
|
|
764 Prefix => New_Occurrence_Of (Indeterm_Ctrl_Type, Loc),
|
|
|
765 Attribute_Name => Name_Tag);
|
|
|
766
|
|
|
767 Analyze (Control);
|
|
|
768 end if;
|
|
|
769
|
|
|
770 if Present (Control) then
|
|
|
771
|
|
|
772 -- Verify that no controlling arguments are statically tagged
|
|
|
773
|
|
|
774 if Debug_Flag_E then
|
|
|
775 Write_Str ("Found Dispatching call");
|
|
|
776 Write_Int (Int (N));
|
|
|
777 Write_Eol;
|
|
|
778 end if;
|
|
|
779
|
|
|
780 Actual := First_Actual (N);
|
|
|
781 while Present (Actual) loop
|
|
|
782 if Actual /= Control then
|
|
|
783
|
|
|
784 if not Is_Controlling_Actual (Actual) then
|
|
|
785 null; -- Can be anything
|
|
|
786
|
|
|
787 elsif Is_Dynamically_Tagged (Actual) then
|
|
|
788 null; -- Valid parameter
|
|
|
789
|
|
|
790 elsif Is_Tag_Indeterminate (Actual) then
|
|
|
791
|
|
|
792 -- The tag is inherited from the enclosing call (the node
|
|
|
793 -- we are currently analyzing). Explicitly expand the
|
|
|
794 -- actual, since the previous call to Expand (from
|
|
|
795 -- Resolve_Call) had no way of knowing about the
|
|
|
796 -- required dispatching.
|
|
|
797
|
|
|
798 Propagate_Tag (Control, Actual);
|
|
|
799
|
|
|
800 else
|
|
|
801 Error_Msg_N
|
|
|
802 ("controlling argument is not dynamically tagged",
|
|
|
803 Actual);
|
|
|
804 return;
|
|
|
805 end if;
|
|
|
806 end if;
|
|
|
807
|
|
|
808 Next_Actual (Actual);
|
|
|
809 end loop;
|
|
|
810
|
|
|
811 -- Mark call as a dispatching call
|
|
|
812
|
|
|
813 Set_Controlling_Argument (N, Control);
|
|
|
814 Check_Restriction (No_Dispatching_Calls, N);
|
|
|
815
|
|
|
816 -- The dispatching call may need to be converted into a direct
|
|
|
817 -- call in certain cases.
|
|
|
818
|
|
|
819 Check_Direct_Call;
|
|
|
820
|
|
|
821 -- If there is a statically tagged actual and a tag-indeterminate
|
|
|
822 -- call to a function of the ancestor (such as that provided by a
|
|
|
823 -- default), then treat this as a dispatching call and propagate
|
|
|
824 -- the tag to the tag-indeterminate call(s).
|
|
|
825
|
|
|
826 elsif Present (Static_Tag) and then Indeterm_Ancestor_Call then
|
|
|
827 Control :=
|
|
|
828 Make_Attribute_Reference (Loc,
|
|
|
829 Prefix =>
|
|
|
830 New_Occurrence_Of (Etype (Static_Tag), Loc),
|
|
|
831 Attribute_Name => Name_Tag);
|
|
|
832
|
|
|
833 Analyze (Control);
|
|
|
834
|
|
|
835 Actual := First_Actual (N);
|
|
|
836 Formal := First_Formal (Subp_Entity);
|
|
|
837 while Present (Actual) loop
|
|
|
838 if Is_Tag_Indeterminate (Actual)
|
|
|
839 and then Is_Controlling_Formal (Formal)
|
|
|
840 then
|
|
|
841 Propagate_Tag (Control, Actual);
|
|
|
842 end if;
|
|
|
843
|
|
|
844 Next_Actual (Actual);
|
|
|
845 Next_Formal (Formal);
|
|
|
846 end loop;
|
|
|
847
|
|
|
848 Check_Dispatching_Context (N);
|
|
|
849
|
|
|
850 elsif Nkind (N) /= N_Function_Call then
|
|
|
851
|
|
|
852 -- The call is not dispatching, so check that there aren't any
|
|
|
853 -- tag-indeterminate abstract calls left among its actuals.
|
|
|
854
|
|
|
855 Actual := First_Actual (N);
|
|
|
856 while Present (Actual) loop
|
|
|
857 if Is_Tag_Indeterminate (Actual) then
|
|
|
858
|
|
|
859 -- Function call case
|
|
|
860
|
|
|
861 if Nkind (Original_Node (Actual)) = N_Function_Call then
|
|
|
862 Func := Entity (Name (Original_Node (Actual)));
|
|
|
863
|
|
|
864 -- If the actual is an attribute then it can't be abstract
|
|
|
865 -- (the only current case of a tag-indeterminate attribute
|
|
|
866 -- is the stream Input attribute).
|
|
|
867
|
|
|
868 elsif Nkind (Original_Node (Actual)) = N_Attribute_Reference
|
|
|
869 then
|
|
|
870 Func := Empty;
|
|
|
871
|
|
|
872 -- Ditto if it is an explicit dereference
|
|
|
873
|
|
|
874 elsif Nkind (Original_Node (Actual)) = N_Explicit_Dereference
|
|
|
875 then
|
|
|
876 Func := Empty;
|
|
|
877
|
|
|
878 -- Only other possibility is a qualified expression whose
|
|
|
879 -- constituent expression is itself a call.
|
|
|
880
|
|
|
881 else
|
|
|
882 Func :=
|
|
|
883 Entity (Name (Original_Node
|
|
|
884 (Expression (Original_Node (Actual)))));
|
|
|
885 end if;
|
|
|
886
|
|
|
887 if Present (Func) and then Is_Abstract_Subprogram (Func) then
|
|
|
888 Error_Msg_N
|
|
|
889 ("call to abstract function must be dispatching",
|
|
|
890 Actual);
|
|
|
891 end if;
|
|
|
892 end if;
|
|
|
893
|
|
|
894 Next_Actual (Actual);
|
|
|
895 end loop;
|
|
|
896
|
|
|
897 Check_Dispatching_Context (N);
|
|
|
898 return;
|
|
|
899
|
|
|
900 elsif Nkind (Parent (N)) in N_Subexpr then
|
|
|
901 Check_Dispatching_Context (N);
|
|
|
902
|
|
|
903 elsif Nkind (Parent (N)) = N_Assignment_Statement
|
|
|
904 and then Is_Class_Wide_Type (Etype (Name (Parent (N))))
|
|
|
905 then
|
|
|
906 return;
|
|
|
907
|
|
|
908 elsif Is_Abstract_Subprogram (Subp_Entity) then
|
|
|
909 Check_Dispatching_Context (N);
|
|
|
910 return;
|
|
|
911 end if;
|
|
|
912
|
|
|
913 else
|
|
|
914 -- If dispatching on result, the enclosing call, if any, will
|
|
|
915 -- determine the controlling argument. Otherwise this is the
|
|
|
916 -- primitive operation of the root type.
|
|
|
917
|
|
|
918 Check_Dispatching_Context (N);
|
|
|
919 end if;
|
|
|
920 end Check_Dispatching_Call;
|
|
|
921
|
|
|
922 ---------------------------------
|
|
|
923 -- Check_Dispatching_Operation --
|
|
|
924 ---------------------------------
|
|
|
925
|
|
|
926 procedure Check_Dispatching_Operation (Subp, Old_Subp : Entity_Id) is
|
|
|
927 procedure Warn_On_Late_Primitive_After_Private_Extension
|
|
|
928 (Typ : Entity_Id;
|
|
|
929 Prim : Entity_Id);
|
|
|
930 -- Prim is a dispatching primitive of the tagged type Typ. Warn on Prim
|
|
|
931 -- if it is a public primitive defined after some private extension of
|
|
|
932 -- the tagged type.
|
|
|
933
|
|
|
934 ----------------------------------------------------
|
|
|
935 -- Warn_On_Late_Primitive_After_Private_Extension --
|
|
|
936 ----------------------------------------------------
|
|
|
937
|
|
|
938 procedure Warn_On_Late_Primitive_After_Private_Extension
|
|
|
939 (Typ : Entity_Id;
|
|
|
940 Prim : Entity_Id)
|
|
|
941 is
|
|
|
942 E : Entity_Id;
|
|
|
943
|
|
|
944 begin
|
|
|
945 if Warn_On_Late_Primitives
|
|
|
946 and then Comes_From_Source (Prim)
|
|
|
947 and then Has_Private_Extension (Typ)
|
|
|
948 and then Is_Package_Or_Generic_Package (Current_Scope)
|
|
|
949 and then not In_Private_Part (Current_Scope)
|
|
|
950 then
|
|
|
951 E := Next_Entity (Typ);
|
|
|
952
|
|
|
953 while E /= Prim loop
|
|
|
954 if Ekind (E) = E_Record_Type_With_Private
|
|
|
955 and then Etype (E) = Typ
|
|
|
956 then
|
|
|
957 Error_Msg_Name_1 := Chars (Typ);
|
|
|
958 Error_Msg_Name_2 := Chars (E);
|
|
|
959 Error_Msg_Sloc := Sloc (E);
|
|
|
960 Error_Msg_N
|
|
|
961 ("?j?primitive of type % defined after private extension "
|
|
|
962 & "% #?", Prim);
|
|
|
963 Error_Msg_Name_1 := Chars (Prim);
|
|
|
964 Error_Msg_Name_2 := Chars (E);
|
|
|
965 Error_Msg_N
|
|
|
966 ("\spec of % should appear before declaration of type %!",
|
|
|
967 Prim);
|
|
|
968 exit;
|
|
|
969 end if;
|
|
|
970
|
|
|
971 Next_Entity (E);
|
|
|
972 end loop;
|
|
|
973 end if;
|
|
|
974 end Warn_On_Late_Primitive_After_Private_Extension;
|
|
|
975
|
|
|
976 -- Local variables
|
|
|
977
|
|
|
978 Body_Is_Last_Primitive : Boolean := False;
|
|
|
979 Has_Dispatching_Parent : Boolean := False;
|
|
|
980 Ovr_Subp : Entity_Id := Empty;
|
|
|
981 Tagged_Type : Entity_Id;
|
|
|
982
|
|
|
983 -- Start of processing for Check_Dispatching_Operation
|
|
|
984
|
|
|
985 begin
|
|
|
986 if not Ekind_In (Subp, E_Function, E_Procedure) then
|
|
|
987 return;
|
|
|
988
|
|
|
989 -- The Default_Initial_Condition procedure is not a primitive subprogram
|
|
|
990 -- even if it relates to a tagged type. This routine is not meant to be
|
|
|
991 -- inherited or overridden.
|
|
|
992
|
|
|
993 elsif Is_DIC_Procedure (Subp) then
|
|
|
994 return;
|
|
|
995
|
|
|
996 -- The "partial" and "full" type invariant procedures are not primitive
|
|
|
997 -- subprograms even if they relate to a tagged type. These routines are
|
|
|
998 -- not meant to be inherited or overridden.
|
|
|
999
|
|
|
1000 elsif Is_Invariant_Procedure (Subp)
|
|
|
1001 or else Is_Partial_Invariant_Procedure (Subp)
|
|
|
1002 then
|
|
|
1003 return;
|
|
|
1004 end if;
|
|
|
1005
|
|
|
1006 Set_Is_Dispatching_Operation (Subp, False);
|
|
|
1007 Tagged_Type := Find_Dispatching_Type (Subp);
|
|
|
1008
|
|
|
1009 -- Ada 2005 (AI-345): Use the corresponding record (if available).
|
|
|
1010 -- Required because primitives of concurrent types are attached
|
|
|
1011 -- to the corresponding record (not to the concurrent type).
|
|
|
1012
|
|
|
1013 if Ada_Version >= Ada_2005
|
|
|
1014 and then Present (Tagged_Type)
|
|
|
1015 and then Is_Concurrent_Type (Tagged_Type)
|
|
|
1016 and then Present (Corresponding_Record_Type (Tagged_Type))
|
|
|
1017 then
|
|
|
1018 Tagged_Type := Corresponding_Record_Type (Tagged_Type);
|
|
|
1019 end if;
|
|
|
1020
|
|
|
1021 -- (AI-345): The task body procedure is not a primitive of the tagged
|
|
|
1022 -- type
|
|
|
1023
|
|
|
1024 if Present (Tagged_Type)
|
|
|
1025 and then Is_Concurrent_Record_Type (Tagged_Type)
|
|
|
1026 and then Present (Corresponding_Concurrent_Type (Tagged_Type))
|
|
|
1027 and then Is_Task_Type (Corresponding_Concurrent_Type (Tagged_Type))
|
|
|
1028 and then Subp = Get_Task_Body_Procedure
|
|
|
1029 (Corresponding_Concurrent_Type (Tagged_Type))
|
|
|
1030 then
|
|
|
1031 return;
|
|
|
1032 end if;
|
|
|
1033
|
|
|
1034 -- If Subp is derived from a dispatching operation then it should
|
|
|
1035 -- always be treated as dispatching. In this case various checks
|
|
|
1036 -- below will be bypassed. Makes sure that late declarations for
|
|
|
1037 -- inherited private subprograms are treated as dispatching, even
|
|
|
1038 -- if the associated tagged type is already frozen.
|
|
|
1039
|
|
|
1040 Has_Dispatching_Parent :=
|
|
|
1041 Present (Alias (Subp))
|
|
|
1042 and then Is_Dispatching_Operation (Alias (Subp));
|
|
|
1043
|
|
|
1044 if No (Tagged_Type) then
|
|
|
1045
|
|
|
1046 -- Ada 2005 (AI-251): Check that Subp is not a primitive associated
|
|
|
1047 -- with an abstract interface type unless the interface acts as a
|
|
|
1048 -- parent type in a derivation. If the interface type is a formal
|
|
|
1049 -- type then the operation is not primitive and therefore legal.
|
|
|
1050
|
|
|
1051 declare
|
|
|
1052 E : Entity_Id;
|
|
|
1053 Typ : Entity_Id;
|
|
|
1054
|
|
|
1055 begin
|
|
|
1056 E := First_Entity (Subp);
|
|
|
1057 while Present (E) loop
|
|
|
1058
|
|
|
1059 -- For an access parameter, check designated type
|
|
|
1060
|
|
|
1061 if Ekind (Etype (E)) = E_Anonymous_Access_Type then
|
|
|
1062 Typ := Designated_Type (Etype (E));
|
|
|
1063 else
|
|
|
1064 Typ := Etype (E);
|
|
|
1065 end if;
|
|
|
1066
|
|
|
1067 if Comes_From_Source (Subp)
|
|
|
1068 and then Is_Interface (Typ)
|
|
|
1069 and then not Is_Class_Wide_Type (Typ)
|
|
|
1070 and then not Is_Derived_Type (Typ)
|
|
|
1071 and then not Is_Generic_Type (Typ)
|
|
|
1072 and then not In_Instance
|
|
|
1073 then
|
|
|
1074 Error_Msg_N ("??declaration of& is too late!", Subp);
|
|
|
1075 Error_Msg_NE -- CODEFIX??
|
|
|
1076 ("\??spec should appear immediately after declaration of "
|
|
|
1077 & "& !", Subp, Typ);
|
|
|
1078 exit;
|
|
|
1079 end if;
|
|
|
1080
|
|
|
1081 Next_Entity (E);
|
|
|
1082 end loop;
|
|
|
1083
|
|
|
1084 -- In case of functions check also the result type
|
|
|
1085
|
|
|
1086 if Ekind (Subp) = E_Function then
|
|
|
1087 if Is_Access_Type (Etype (Subp)) then
|
|
|
1088 Typ := Designated_Type (Etype (Subp));
|
|
|
1089 else
|
|
|
1090 Typ := Etype (Subp);
|
|
|
1091 end if;
|
|
|
1092
|
|
|
1093 -- The following should be better commented, especially since
|
|
|
1094 -- we just added several new conditions here ???
|
|
|
1095
|
|
|
1096 if Comes_From_Source (Subp)
|
|
|
1097 and then Is_Interface (Typ)
|
|
|
1098 and then not Is_Class_Wide_Type (Typ)
|
|
|
1099 and then not Is_Derived_Type (Typ)
|
|
|
1100 and then not Is_Generic_Type (Typ)
|
|
|
1101 and then not In_Instance
|
|
|
1102 then
|
|
|
1103 Error_Msg_N ("??declaration of& is too late!", Subp);
|
|
|
1104 Error_Msg_NE
|
|
|
1105 ("\??spec should appear immediately after declaration of "
|
|
|
1106 & "& !", Subp, Typ);
|
|
|
1107 end if;
|
|
|
1108 end if;
|
|
|
1109 end;
|
|
|
1110
|
|
|
1111 return;
|
|
|
1112
|
|
|
1113 -- The subprograms build internally after the freezing point (such as
|
|
|
1114 -- init procs, interface thunks, type support subprograms, and Offset
|
|
|
1115 -- to top functions for accessing interface components in variable
|
|
|
1116 -- size tagged types) are not primitives.
|
|
|
1117
|
|
|
1118 elsif Is_Frozen (Tagged_Type)
|
|
|
1119 and then not Comes_From_Source (Subp)
|
|
|
1120 and then not Has_Dispatching_Parent
|
|
|
1121 then
|
|
|
1122 -- Complete decoration of internally built subprograms that override
|
|
|
1123 -- a dispatching primitive. These entities correspond with the
|
|
|
1124 -- following cases:
|
|
|
1125
|
|
|
1126 -- 1. Ada 2005 (AI-391): Wrapper functions built by the expander
|
|
|
1127 -- to override functions of nonabstract null extensions. These
|
|
|
1128 -- primitives were added to the list of primitives of the tagged
|
|
|
1129 -- type by Make_Controlling_Function_Wrappers. However, attribute
|
|
|
1130 -- Is_Dispatching_Operation must be set to true.
|
|
|
1131
|
|
|
1132 -- 2. Ada 2005 (AI-251): Wrapper procedures of null interface
|
|
|
1133 -- primitives.
|
|
|
1134
|
|
|
1135 -- 3. Subprograms associated with stream attributes (built by
|
|
|
1136 -- New_Stream_Subprogram)
|
|
|
1137
|
|
|
1138 -- 4. Wrapper built for inherited operations with inherited class-
|
|
|
1139 -- wide conditions, where the conditions include calls to other
|
|
|
1140 -- overridden primitives. The wrappers include checks on these
|
|
|
1141 -- modified conditions. (AI12-113).
|
|
|
1142
|
|
|
1143 if Present (Old_Subp)
|
|
|
1144 and then Present (Overridden_Operation (Subp))
|
|
|
1145 and then Is_Dispatching_Operation (Old_Subp)
|
|
|
1146 then
|
|
|
1147 pragma Assert
|
|
|
1148 ((Ekind (Subp) = E_Function
|
|
|
1149 and then Is_Dispatching_Operation (Old_Subp)
|
|
|
1150 and then Is_Null_Extension (Base_Type (Etype (Subp))))
|
|
|
1151
|
|
|
1152 or else
|
|
|
1153 (Ekind (Subp) = E_Procedure
|
|
|
1154 and then Is_Dispatching_Operation (Old_Subp)
|
|
|
1155 and then Present (Alias (Old_Subp))
|
|
|
1156 and then Is_Null_Interface_Primitive
|
|
|
1157 (Ultimate_Alias (Old_Subp)))
|
|
|
1158
|
|
|
1159 or else Get_TSS_Name (Subp) = TSS_Stream_Read
|
|
|
1160 or else Get_TSS_Name (Subp) = TSS_Stream_Write
|
|
|
1161
|
|
|
1162 or else Present (Contract (Overridden_Operation (Subp))));
|
|
|
1163
|
|
|
1164 Check_Controlling_Formals (Tagged_Type, Subp);
|
|
|
1165 Override_Dispatching_Operation (Tagged_Type, Old_Subp, Subp);
|
|
|
1166 Set_Is_Dispatching_Operation (Subp);
|
|
|
1167 end if;
|
|
|
1168
|
|
|
1169 return;
|
|
|
1170
|
|
|
1171 -- The operation may be a child unit, whose scope is the defining
|
|
|
1172 -- package, but which is not a primitive operation of the type.
|
|
|
1173
|
|
|
1174 elsif Is_Child_Unit (Subp) then
|
|
|
1175 return;
|
|
|
1176
|
|
|
1177 -- If the subprogram is not defined in a package spec, the only case
|
|
|
1178 -- where it can be a dispatching op is when it overrides an operation
|
|
|
1179 -- before the freezing point of the type.
|
|
|
1180
|
|
|
1181 elsif ((not Is_Package_Or_Generic_Package (Scope (Subp)))
|
|
|
1182 or else In_Package_Body (Scope (Subp)))
|
|
|
1183 and then not Has_Dispatching_Parent
|
|
|
1184 then
|
|
|
1185 if not Comes_From_Source (Subp)
|
|
|
1186 or else (Present (Old_Subp) and then not Is_Frozen (Tagged_Type))
|
|
|
1187 then
|
|
|
1188 null;
|
|
|
1189
|
|
|
1190 -- If the type is already frozen, the overriding is not allowed
|
|
|
1191 -- except when Old_Subp is not a dispatching operation (which can
|
|
|
1192 -- occur when Old_Subp was inherited by an untagged type). However,
|
|
|
1193 -- a body with no previous spec freezes the type *after* its
|
|
|
1194 -- declaration, and therefore is a legal overriding (unless the type
|
|
|
1195 -- has already been frozen). Only the first such body is legal.
|
|
|
1196
|
|
|
1197 elsif Present (Old_Subp)
|
|
|
1198 and then Is_Dispatching_Operation (Old_Subp)
|
|
|
1199 then
|
|
|
1200 if Comes_From_Source (Subp)
|
|
|
1201 and then
|
|
|
1202 (Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Body
|
|
|
1203 or else Nkind (Unit_Declaration_Node (Subp)) in N_Body_Stub)
|
|
|
1204 then
|
|
|
1205 declare
|
|
|
1206 Subp_Body : constant Node_Id := Unit_Declaration_Node (Subp);
|
|
|
1207 Decl_Item : Node_Id;
|
|
|
1208
|
|
|
1209 begin
|
|
|
1210 -- ??? The checks here for whether the type has been frozen
|
|
|
1211 -- prior to the new body are not complete. It's not simple
|
|
|
1212 -- to check frozenness at this point since the body has
|
|
|
1213 -- already caused the type to be prematurely frozen in
|
|
|
1214 -- Analyze_Declarations, but we're forced to recheck this
|
|
|
1215 -- here because of the odd rule interpretation that allows
|
|
|
1216 -- the overriding if the type wasn't frozen prior to the
|
|
|
1217 -- body. The freezing action should probably be delayed
|
|
|
1218 -- until after the spec is seen, but that's a tricky
|
|
|
1219 -- change to the delicate freezing code.
|
|
|
1220
|
|
|
1221 -- Look at each declaration following the type up until the
|
|
|
1222 -- new subprogram body. If any of the declarations is a body
|
|
|
1223 -- then the type has been frozen already so the overriding
|
|
|
1224 -- primitive is illegal.
|
|
|
1225
|
|
|
1226 Decl_Item := Next (Parent (Tagged_Type));
|
|
|
1227 while Present (Decl_Item)
|
|
|
1228 and then (Decl_Item /= Subp_Body)
|
|
|
1229 loop
|
|
|
1230 if Comes_From_Source (Decl_Item)
|
|
|
1231 and then (Nkind (Decl_Item) in N_Proper_Body
|
|
|
1232 or else Nkind (Decl_Item) in N_Body_Stub)
|
|
|
1233 then
|
|
|
1234 Error_Msg_N ("overriding of& is too late!", Subp);
|
|
|
1235 Error_Msg_N
|
|
|
1236 ("\spec should appear immediately after the type!",
|
|
|
1237 Subp);
|
|
|
1238 exit;
|
|
|
1239 end if;
|
|
|
1240
|
|
|
1241 Next (Decl_Item);
|
|
|
1242 end loop;
|
|
|
1243
|
|
|
1244 -- If the subprogram doesn't follow in the list of
|
|
|
1245 -- declarations including the type then the type has
|
|
|
1246 -- definitely been frozen already and the body is illegal.
|
|
|
1247
|
|
|
1248 if No (Decl_Item) then
|
|
|
1249 Error_Msg_N ("overriding of& is too late!", Subp);
|
|
|
1250 Error_Msg_N
|
|
|
1251 ("\spec should appear immediately after the type!",
|
|
|
1252 Subp);
|
|
|
1253
|
|
|
1254 elsif Is_Frozen (Subp) then
|
|
|
1255
|
|
|
1256 -- The subprogram body declares a primitive operation.
|
|
|
1257 -- If the subprogram is already frozen, we must update
|
|
|
1258 -- its dispatching information explicitly here. The
|
|
|
1259 -- information is taken from the overridden subprogram.
|
|
|
1260 -- We must also generate a cross-reference entry because
|
|
|
1261 -- references to other primitives were already created
|
|
|
1262 -- when type was frozen.
|
|
|
1263
|
|
|
1264 Body_Is_Last_Primitive := True;
|
|
|
1265
|
|
|
1266 if Present (DTC_Entity (Old_Subp)) then
|
|
|
1267 Set_DTC_Entity (Subp, DTC_Entity (Old_Subp));
|
|
|
1268 Set_DT_Position_Value (Subp, DT_Position (Old_Subp));
|
|
|
1269
|
|
|
1270 if not Restriction_Active (No_Dispatching_Calls) then
|
|
|
1271 if Building_Static_DT (Tagged_Type) then
|
|
|
1272
|
|
|
1273 -- If the static dispatch table has not been
|
|
|
1274 -- built then there is nothing else to do now;
|
|
|
1275 -- otherwise we notify that we cannot build the
|
|
|
1276 -- static dispatch table.
|
|
|
1277
|
|
|
1278 if Has_Dispatch_Table (Tagged_Type) then
|
|
|
1279 Error_Msg_N
|
|
|
1280 ("overriding of& is too late for building "
|
|
|
1281 & " static dispatch tables!", Subp);
|
|
|
1282 Error_Msg_N
|
|
|
1283 ("\spec should appear immediately after "
|
|
|
1284 & "the type!", Subp);
|
|
|
1285 end if;
|
|
|
1286
|
|
|
1287 -- No code required to register primitives in VM
|
|
|
1288 -- targets
|
|
|
1289
|
|
|
1290 elsif not Tagged_Type_Expansion then
|
|
|
1291 null;
|
|
|
1292
|
|
|
1293 else
|
|
|
1294 Insert_Actions_After (Subp_Body,
|
|
|
1295 Register_Primitive (Sloc (Subp_Body),
|
|
|
1296 Prim => Subp));
|
|
|
1297 end if;
|
|
|
1298
|
|
|
1299 -- Indicate that this is an overriding operation,
|
|
|
1300 -- and replace the overridden entry in the list of
|
|
|
1301 -- primitive operations, which is used for xref
|
|
|
1302 -- generation subsequently.
|
|
|
1303
|
|
|
1304 Generate_Reference (Tagged_Type, Subp, 'P', False);
|
|
|
1305 Override_Dispatching_Operation
|
|
|
1306 (Tagged_Type, Old_Subp, Subp);
|
|
|
1307 end if;
|
|
|
1308 end if;
|
|
|
1309 end if;
|
|
|
1310 end;
|
|
|
1311
|
|
|
1312 else
|
|
|
1313 Error_Msg_N ("overriding of& is too late!", Subp);
|
|
|
1314 Error_Msg_N
|
|
|
1315 ("\subprogram spec should appear immediately after the type!",
|
|
|
1316 Subp);
|
|
|
1317 end if;
|
|
|
1318
|
|
|
1319 -- If the type is not frozen yet and we are not in the overriding
|
|
|
1320 -- case it looks suspiciously like an attempt to define a primitive
|
|
|
1321 -- operation, which requires the declaration to be in a package spec
|
|
|
1322 -- (3.2.3(6)). Only report cases where the type and subprogram are
|
|
|
1323 -- in the same declaration list (by checking the enclosing parent
|
|
|
1324 -- declarations), to avoid spurious warnings on subprograms in
|
|
|
1325 -- instance bodies when the type is declared in the instance spec
|
|
|
1326 -- but hasn't been frozen by the instance body.
|
|
|
1327
|
|
|
1328 elsif not Is_Frozen (Tagged_Type)
|
|
|
1329 and then In_Same_List (Parent (Tagged_Type), Parent (Parent (Subp)))
|
|
|
1330 then
|
|
|
1331 Error_Msg_N
|
|
|
1332 ("??not dispatching (must be defined in a package spec)", Subp);
|
|
|
1333 return;
|
|
|
1334
|
|
|
1335 -- When the type is frozen, it is legitimate to define a new
|
|
|
1336 -- non-primitive operation.
|
|
|
1337
|
|
|
1338 else
|
|
|
1339 return;
|
|
|
1340 end if;
|
|
|
1341
|
|
|
1342 -- Now, we are sure that the scope is a package spec. If the subprogram
|
|
|
1343 -- is declared after the freezing point of the type that's an error
|
|
|
1344
|
|
|
1345 elsif Is_Frozen (Tagged_Type) and then not Has_Dispatching_Parent then
|
|
|
1346 Error_Msg_N ("this primitive operation is declared too late", Subp);
|
|
|
1347 Error_Msg_NE
|
|
|
1348 ("??no primitive operations for& after this line",
|
|
|
1349 Freeze_Node (Tagged_Type),
|
|
|
1350 Tagged_Type);
|
|
|
1351 return;
|
|
|
1352 end if;
|
|
|
1353
|
|
|
1354 Check_Controlling_Formals (Tagged_Type, Subp);
|
|
|
1355
|
|
|
1356 Ovr_Subp := Old_Subp;
|
|
|
1357
|
|
|
1358 -- [Ada 2012:AI-0125]: Search for inherited hidden primitive that may be
|
|
|
1359 -- overridden by Subp. This only applies to source subprograms, and
|
|
|
1360 -- their declaration must carry an explicit overriding indicator.
|
|
|
1361
|
|
|
1362 if No (Ovr_Subp)
|
|
|
1363 and then Ada_Version >= Ada_2012
|
|
|
1364 and then Comes_From_Source (Subp)
|
|
|
1365 and then
|
|
|
1366 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
|
|
|
1367 then
|
|
|
1368 Ovr_Subp := Find_Hidden_Overridden_Primitive (Subp);
|
|
|
1369
|
|
|
1370 -- Verify that the proper overriding indicator has been supplied.
|
|
|
1371
|
|
|
1372 if Present (Ovr_Subp)
|
|
|
1373 and then
|
|
|
1374 not Must_Override (Specification (Unit_Declaration_Node (Subp)))
|
|
|
1375 then
|
|
|
1376 Error_Msg_NE ("missing overriding indicator for&", Subp, Subp);
|
|
|
1377 end if;
|
|
|
1378 end if;
|
|
|
1379
|
|
|
1380 -- Now it should be a correct primitive operation, put it in the list
|
|
|
1381
|
|
|
1382 if Present (Ovr_Subp) then
|
|
|
1383
|
|
|
1384 -- If the type has interfaces we complete this check after we set
|
|
|
1385 -- attribute Is_Dispatching_Operation.
|
|
|
1386
|
|
|
1387 Check_Subtype_Conformant (Subp, Ovr_Subp);
|
|
|
1388
|
|
|
1389 -- A primitive operation with the name of a primitive controlled
|
|
|
1390 -- operation does not override a non-visible overriding controlled
|
|
|
1391 -- operation, i.e. one declared in a private part when the full
|
|
|
1392 -- view of a type is controlled. Conversely, it will override a
|
|
|
1393 -- visible operation that may be declared in a partial view when
|
|
|
1394 -- the full view is controlled.
|
|
|
1395
|
|
|
1396 if Nam_In (Chars (Subp), Name_Initialize, Name_Adjust, Name_Finalize)
|
|
|
1397 and then Is_Controlled (Tagged_Type)
|
|
|
1398 and then not Is_Visibly_Controlled (Tagged_Type)
|
|
|
1399 and then not Is_Inherited_Public_Operation (Ovr_Subp)
|
|
|
1400 then
|
|
|
1401 Set_Overridden_Operation (Subp, Empty);
|
|
|
1402
|
|
|
1403 -- If the subprogram specification carries an overriding
|
|
|
1404 -- indicator, no need for the warning: it is either redundant,
|
|
|
1405 -- or else an error will be reported.
|
|
|
1406
|
|
|
1407 if Nkind (Parent (Subp)) = N_Procedure_Specification
|
|
|
1408 and then
|
|
|
1409 (Must_Override (Parent (Subp))
|
|
|
1410 or else Must_Not_Override (Parent (Subp)))
|
|
|
1411 then
|
|
|
1412 null;
|
|
|
1413
|
|
|
1414 -- Here we need the warning
|
|
|
1415
|
|
|
1416 else
|
|
|
1417 Error_Msg_NE
|
|
|
1418 ("operation does not override inherited&??", Subp, Subp);
|
|
|
1419 end if;
|
|
|
1420
|
|
|
1421 else
|
|
|
1422 Override_Dispatching_Operation (Tagged_Type, Ovr_Subp, Subp);
|
|
|
1423
|
|
|
1424 -- Ada 2005 (AI-251): In case of late overriding of a primitive
|
|
|
1425 -- that covers abstract interface subprograms we must register it
|
|
|
1426 -- in all the secondary dispatch tables associated with abstract
|
|
|
1427 -- interfaces. We do this now only if not building static tables,
|
|
|
1428 -- nor when the expander is inactive (we avoid trying to register
|
|
|
1429 -- primitives in semantics-only mode, since the type may not have
|
|
|
1430 -- an associated dispatch table). Otherwise the patch code is
|
|
|
1431 -- emitted after those tables are built, to prevent access before
|
|
|
1432 -- elaboration in gigi.
|
|
|
1433
|
|
|
1434 if Body_Is_Last_Primitive and then Expander_Active then
|
|
|
1435 declare
|
|
|
1436 Subp_Body : constant Node_Id := Unit_Declaration_Node (Subp);
|
|
|
1437 Elmt : Elmt_Id;
|
|
|
1438 Prim : Node_Id;
|
|
|
1439
|
|
|
1440 begin
|
|
|
1441 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
|
1442 while Present (Elmt) loop
|
|
|
1443 Prim := Node (Elmt);
|
|
|
1444
|
|
|
1445 -- No code required to register primitives in VM targets
|
|
|
1446
|
|
|
1447 if Present (Alias (Prim))
|
|
|
1448 and then Present (Interface_Alias (Prim))
|
|
|
1449 and then Alias (Prim) = Subp
|
|
|
1450 and then not Building_Static_DT (Tagged_Type)
|
|
|
1451 and then Tagged_Type_Expansion
|
|
|
1452 then
|
|
|
1453 Insert_Actions_After (Subp_Body,
|
|
|
1454 Register_Primitive (Sloc (Subp_Body), Prim => Prim));
|
|
|
1455 end if;
|
|
|
1456
|
|
|
1457 Next_Elmt (Elmt);
|
|
|
1458 end loop;
|
|
|
1459
|
|
|
1460 -- Redisplay the contents of the updated dispatch table
|
|
|
1461
|
|
|
1462 if Debug_Flag_ZZ then
|
|
|
1463 Write_Str ("Late overriding: ");
|
|
|
1464 Write_DT (Tagged_Type);
|
|
|
1465 end if;
|
|
|
1466 end;
|
|
|
1467 end if;
|
|
|
1468 end if;
|
|
|
1469
|
|
|
1470 -- If the tagged type is a concurrent type then we must be compiling
|
|
|
1471 -- with no code generation (we are either compiling a generic unit or
|
|
|
1472 -- compiling under -gnatc mode) because we have previously tested that
|
|
|
1473 -- no serious errors has been reported. In this case we do not add the
|
|
|
1474 -- primitive to the list of primitives of Tagged_Type but we leave the
|
|
|
1475 -- primitive decorated as a dispatching operation to be able to analyze
|
|
|
1476 -- and report errors associated with the Object.Operation notation.
|
|
|
1477
|
|
|
1478 elsif Is_Concurrent_Type (Tagged_Type) then
|
|
|
1479 pragma Assert (not Expander_Active);
|
|
|
1480
|
|
|
1481 -- Attach operation to list of primitives of the synchronized type
|
|
|
1482 -- itself, for ASIS use.
|
|
|
1483
|
|
131
|
1484 Add_Dispatching_Operation (Tagged_Type, Subp);
|
|
111
|
1485
|
|
|
1486 -- If no old subprogram, then we add this as a dispatching operation,
|
|
|
1487 -- but we avoid doing this if an error was posted, to prevent annoying
|
|
|
1488 -- cascaded errors.
|
|
|
1489
|
|
|
1490 elsif not Error_Posted (Subp) then
|
|
|
1491 Add_Dispatching_Operation (Tagged_Type, Subp);
|
|
|
1492 end if;
|
|
|
1493
|
|
|
1494 Set_Is_Dispatching_Operation (Subp, True);
|
|
|
1495
|
|
|
1496 -- Ada 2005 (AI-251): If the type implements interfaces we must check
|
|
|
1497 -- subtype conformance against all the interfaces covered by this
|
|
|
1498 -- primitive.
|
|
|
1499
|
|
|
1500 if Present (Ovr_Subp)
|
|
|
1501 and then Has_Interfaces (Tagged_Type)
|
|
|
1502 then
|
|
|
1503 declare
|
|
|
1504 Ifaces_List : Elist_Id;
|
|
|
1505 Iface_Elmt : Elmt_Id;
|
|
|
1506 Iface_Prim_Elmt : Elmt_Id;
|
|
|
1507 Iface_Prim : Entity_Id;
|
|
|
1508 Ret_Typ : Entity_Id;
|
|
|
1509
|
|
|
1510 begin
|
|
|
1511 Collect_Interfaces (Tagged_Type, Ifaces_List);
|
|
|
1512
|
|
|
1513 Iface_Elmt := First_Elmt (Ifaces_List);
|
|
|
1514 while Present (Iface_Elmt) loop
|
|
|
1515 if not Is_Ancestor (Node (Iface_Elmt), Tagged_Type) then
|
|
|
1516 Iface_Prim_Elmt :=
|
|
|
1517 First_Elmt (Primitive_Operations (Node (Iface_Elmt)));
|
|
|
1518 while Present (Iface_Prim_Elmt) loop
|
|
|
1519 Iface_Prim := Node (Iface_Prim_Elmt);
|
|
|
1520
|
|
|
1521 if Is_Interface_Conformant
|
|
|
1522 (Tagged_Type, Iface_Prim, Subp)
|
|
|
1523 then
|
|
|
1524 -- Handle procedures, functions whose return type
|
|
|
1525 -- matches, or functions not returning interfaces
|
|
|
1526
|
|
|
1527 if Ekind (Subp) = E_Procedure
|
|
|
1528 or else Etype (Iface_Prim) = Etype (Subp)
|
|
|
1529 or else not Is_Interface (Etype (Iface_Prim))
|
|
|
1530 then
|
|
|
1531 Check_Subtype_Conformant
|
|
|
1532 (New_Id => Subp,
|
|
|
1533 Old_Id => Iface_Prim,
|
|
|
1534 Err_Loc => Subp,
|
|
|
1535 Skip_Controlling_Formals => True);
|
|
|
1536
|
|
|
1537 -- Handle functions returning interfaces
|
|
|
1538
|
|
|
1539 elsif Implements_Interface
|
|
|
1540 (Etype (Subp), Etype (Iface_Prim))
|
|
|
1541 then
|
|
|
1542 -- Temporarily force both entities to return the
|
|
|
1543 -- same type. Required because Subtype_Conformant
|
|
|
1544 -- does not handle this case.
|
|
|
1545
|
|
|
1546 Ret_Typ := Etype (Iface_Prim);
|
|
|
1547 Set_Etype (Iface_Prim, Etype (Subp));
|
|
|
1548
|
|
|
1549 Check_Subtype_Conformant
|
|
|
1550 (New_Id => Subp,
|
|
|
1551 Old_Id => Iface_Prim,
|
|
|
1552 Err_Loc => Subp,
|
|
|
1553 Skip_Controlling_Formals => True);
|
|
|
1554
|
|
|
1555 Set_Etype (Iface_Prim, Ret_Typ);
|
|
|
1556 end if;
|
|
|
1557 end if;
|
|
|
1558
|
|
|
1559 Next_Elmt (Iface_Prim_Elmt);
|
|
|
1560 end loop;
|
|
|
1561 end if;
|
|
|
1562
|
|
|
1563 Next_Elmt (Iface_Elmt);
|
|
|
1564 end loop;
|
|
|
1565 end;
|
|
|
1566 end if;
|
|
|
1567
|
|
|
1568 if not Body_Is_Last_Primitive then
|
|
|
1569 Set_DT_Position_Value (Subp, No_Uint);
|
|
|
1570
|
|
|
1571 elsif Has_Controlled_Component (Tagged_Type)
|
|
|
1572 and then Nam_In (Chars (Subp), Name_Initialize,
|
|
|
1573 Name_Adjust,
|
|
|
1574 Name_Finalize,
|
|
|
1575 Name_Finalize_Address)
|
|
|
1576 then
|
|
|
1577 declare
|
|
|
1578 F_Node : constant Node_Id := Freeze_Node (Tagged_Type);
|
|
|
1579 Decl : Node_Id;
|
|
|
1580 Old_P : Entity_Id;
|
|
|
1581 Old_Bod : Node_Id;
|
|
|
1582 Old_Spec : Entity_Id;
|
|
|
1583
|
|
|
1584 C_Names : constant array (1 .. 4) of Name_Id :=
|
|
|
1585 (Name_Initialize,
|
|
|
1586 Name_Adjust,
|
|
|
1587 Name_Finalize,
|
|
|
1588 Name_Finalize_Address);
|
|
|
1589
|
|
|
1590 D_Names : constant array (1 .. 4) of TSS_Name_Type :=
|
|
|
1591 (TSS_Deep_Initialize,
|
|
|
1592 TSS_Deep_Adjust,
|
|
|
1593 TSS_Deep_Finalize,
|
|
|
1594 TSS_Finalize_Address);
|
|
|
1595
|
|
|
1596 begin
|
|
|
1597 -- Remove previous controlled function which was constructed and
|
|
|
1598 -- analyzed when the type was frozen. This requires removing the
|
|
|
1599 -- body of the redefined primitive, as well as its specification
|
|
|
1600 -- if needed (there is no spec created for Deep_Initialize, see
|
|
|
1601 -- exp_ch3.adb). We must also dismantle the exception information
|
|
|
1602 -- that may have been generated for it when front end zero-cost
|
|
|
1603 -- tables are enabled.
|
|
|
1604
|
|
|
1605 for J in D_Names'Range loop
|
|
|
1606 Old_P := TSS (Tagged_Type, D_Names (J));
|
|
|
1607
|
|
|
1608 if Present (Old_P)
|
|
|
1609 and then Chars (Subp) = C_Names (J)
|
|
|
1610 then
|
|
|
1611 Old_Bod := Unit_Declaration_Node (Old_P);
|
|
|
1612 Remove (Old_Bod);
|
|
|
1613 Set_Is_Eliminated (Old_P);
|
|
|
1614 Set_Scope (Old_P, Scope (Current_Scope));
|
|
|
1615
|
|
|
1616 if Nkind (Old_Bod) = N_Subprogram_Body
|
|
|
1617 and then Present (Corresponding_Spec (Old_Bod))
|
|
|
1618 then
|
|
|
1619 Old_Spec := Corresponding_Spec (Old_Bod);
|
|
|
1620 Set_Has_Completion (Old_Spec, False);
|
|
|
1621 end if;
|
|
|
1622 end if;
|
|
|
1623 end loop;
|
|
|
1624
|
|
|
1625 Build_Late_Proc (Tagged_Type, Chars (Subp));
|
|
|
1626
|
|
|
1627 -- The new operation is added to the actions of the freeze node
|
|
|
1628 -- for the type, but this node has already been analyzed, so we
|
|
|
1629 -- must retrieve and analyze explicitly the new body.
|
|
|
1630
|
|
|
1631 if Present (F_Node)
|
|
|
1632 and then Present (Actions (F_Node))
|
|
|
1633 then
|
|
|
1634 Decl := Last (Actions (F_Node));
|
|
|
1635 Analyze (Decl);
|
|
|
1636 end if;
|
|
|
1637 end;
|
|
|
1638 end if;
|
|
|
1639
|
|
|
1640 -- For similarity with record extensions, in Ada 9X the language should
|
|
|
1641 -- have disallowed adding visible operations to a tagged type after
|
|
|
1642 -- deriving a private extension from it. Report a warning if this
|
|
|
1643 -- primitive is defined after a private extension of Tagged_Type.
|
|
|
1644
|
|
|
1645 Warn_On_Late_Primitive_After_Private_Extension (Tagged_Type, Subp);
|
|
|
1646 end Check_Dispatching_Operation;
|
|
|
1647
|
|
|
1648 ------------------------------------------
|
|
|
1649 -- Check_Operation_From_Incomplete_Type --
|
|
|
1650 ------------------------------------------
|
|
|
1651
|
|
|
1652 procedure Check_Operation_From_Incomplete_Type
|
|
|
1653 (Subp : Entity_Id;
|
|
|
1654 Typ : Entity_Id)
|
|
|
1655 is
|
|
|
1656 Full : constant Entity_Id := Full_View (Typ);
|
|
|
1657 Parent_Typ : constant Entity_Id := Etype (Full);
|
|
|
1658 Old_Prim : constant Elist_Id := Primitive_Operations (Parent_Typ);
|
|
|
1659 New_Prim : constant Elist_Id := Primitive_Operations (Full);
|
|
|
1660 Op1, Op2 : Elmt_Id;
|
|
|
1661 Prev : Elmt_Id := No_Elmt;
|
|
|
1662
|
|
|
1663 function Derives_From (Parent_Subp : Entity_Id) return Boolean;
|
|
|
1664 -- Check that Subp has profile of an operation derived from Parent_Subp.
|
|
|
1665 -- Subp must have a parameter or result type that is Typ or an access
|
|
|
1666 -- parameter or access result type that designates Typ.
|
|
|
1667
|
|
|
1668 ------------------
|
|
|
1669 -- Derives_From --
|
|
|
1670 ------------------
|
|
|
1671
|
|
|
1672 function Derives_From (Parent_Subp : Entity_Id) return Boolean is
|
|
|
1673 F1, F2 : Entity_Id;
|
|
|
1674
|
|
|
1675 begin
|
|
|
1676 if Chars (Parent_Subp) /= Chars (Subp) then
|
|
|
1677 return False;
|
|
|
1678 end if;
|
|
|
1679
|
|
|
1680 -- Check that the type of controlling formals is derived from the
|
|
|
1681 -- parent subprogram's controlling formal type (or designated type
|
|
|
1682 -- if the formal type is an anonymous access type).
|
|
|
1683
|
|
|
1684 F1 := First_Formal (Parent_Subp);
|
|
|
1685 F2 := First_Formal (Subp);
|
|
|
1686 while Present (F1) and then Present (F2) loop
|
|
|
1687 if Ekind (Etype (F1)) = E_Anonymous_Access_Type then
|
|
|
1688 if Ekind (Etype (F2)) /= E_Anonymous_Access_Type then
|
|
|
1689 return False;
|
|
|
1690 elsif Designated_Type (Etype (F1)) = Parent_Typ
|
|
|
1691 and then Designated_Type (Etype (F2)) /= Full
|
|
|
1692 then
|
|
|
1693 return False;
|
|
|
1694 end if;
|
|
|
1695
|
|
|
1696 elsif Ekind (Etype (F2)) = E_Anonymous_Access_Type then
|
|
|
1697 return False;
|
|
|
1698
|
|
|
1699 elsif Etype (F1) = Parent_Typ and then Etype (F2) /= Full then
|
|
|
1700 return False;
|
|
|
1701 end if;
|
|
|
1702
|
|
|
1703 Next_Formal (F1);
|
|
|
1704 Next_Formal (F2);
|
|
|
1705 end loop;
|
|
|
1706
|
|
|
1707 -- Check that a controlling result type is derived from the parent
|
|
|
1708 -- subprogram's result type (or designated type if the result type
|
|
|
1709 -- is an anonymous access type).
|
|
|
1710
|
|
|
1711 if Ekind (Parent_Subp) = E_Function then
|
|
|
1712 if Ekind (Subp) /= E_Function then
|
|
|
1713 return False;
|
|
|
1714
|
|
|
1715 elsif Ekind (Etype (Parent_Subp)) = E_Anonymous_Access_Type then
|
|
|
1716 if Ekind (Etype (Subp)) /= E_Anonymous_Access_Type then
|
|
|
1717 return False;
|
|
|
1718
|
|
|
1719 elsif Designated_Type (Etype (Parent_Subp)) = Parent_Typ
|
|
|
1720 and then Designated_Type (Etype (Subp)) /= Full
|
|
|
1721 then
|
|
|
1722 return False;
|
|
|
1723 end if;
|
|
|
1724
|
|
|
1725 elsif Ekind (Etype (Subp)) = E_Anonymous_Access_Type then
|
|
|
1726 return False;
|
|
|
1727
|
|
|
1728 elsif Etype (Parent_Subp) = Parent_Typ
|
|
|
1729 and then Etype (Subp) /= Full
|
|
|
1730 then
|
|
|
1731 return False;
|
|
|
1732 end if;
|
|
|
1733
|
|
|
1734 elsif Ekind (Subp) = E_Function then
|
|
|
1735 return False;
|
|
|
1736 end if;
|
|
|
1737
|
|
|
1738 return No (F1) and then No (F2);
|
|
|
1739 end Derives_From;
|
|
|
1740
|
|
|
1741 -- Start of processing for Check_Operation_From_Incomplete_Type
|
|
|
1742
|
|
|
1743 begin
|
|
|
1744 -- The operation may override an inherited one, or may be a new one
|
|
|
1745 -- altogether. The inherited operation will have been hidden by the
|
|
|
1746 -- current one at the point of the type derivation, so it does not
|
|
|
1747 -- appear in the list of primitive operations of the type. We have to
|
|
|
1748 -- find the proper place of insertion in the list of primitive opera-
|
|
|
1749 -- tions by iterating over the list for the parent type.
|
|
|
1750
|
|
|
1751 Op1 := First_Elmt (Old_Prim);
|
|
|
1752 Op2 := First_Elmt (New_Prim);
|
|
|
1753 while Present (Op1) and then Present (Op2) loop
|
|
|
1754 if Derives_From (Node (Op1)) then
|
|
|
1755 if No (Prev) then
|
|
|
1756
|
|
|
1757 -- Avoid adding it to the list of primitives if already there
|
|
|
1758
|
|
|
1759 if Node (Op2) /= Subp then
|
|
|
1760 Prepend_Elmt (Subp, New_Prim);
|
|
|
1761 end if;
|
|
|
1762
|
|
|
1763 else
|
|
|
1764 Insert_Elmt_After (Subp, Prev);
|
|
|
1765 end if;
|
|
|
1766
|
|
|
1767 return;
|
|
|
1768 end if;
|
|
|
1769
|
|
|
1770 Prev := Op2;
|
|
|
1771 Next_Elmt (Op1);
|
|
|
1772 Next_Elmt (Op2);
|
|
|
1773 end loop;
|
|
|
1774
|
|
|
1775 -- Operation is a new primitive
|
|
|
1776
|
|
|
1777 Append_Elmt (Subp, New_Prim);
|
|
|
1778 end Check_Operation_From_Incomplete_Type;
|
|
|
1779
|
|
|
1780 ---------------------------------------
|
|
|
1781 -- Check_Operation_From_Private_View --
|
|
|
1782 ---------------------------------------
|
|
|
1783
|
|
|
1784 procedure Check_Operation_From_Private_View (Subp, Old_Subp : Entity_Id) is
|
|
|
1785 Tagged_Type : Entity_Id;
|
|
|
1786
|
|
|
1787 begin
|
|
|
1788 if Is_Dispatching_Operation (Alias (Subp)) then
|
|
|
1789 Set_Scope (Subp, Current_Scope);
|
|
|
1790 Tagged_Type := Find_Dispatching_Type (Subp);
|
|
|
1791
|
|
|
1792 -- Add Old_Subp to primitive operations if not already present
|
|
|
1793
|
|
|
1794 if Present (Tagged_Type) and then Is_Tagged_Type (Tagged_Type) then
|
|
131
|
1795 Add_Dispatching_Operation (Tagged_Type, Old_Subp);
|
|
111
|
1796
|
|
|
1797 -- If Old_Subp isn't already marked as dispatching then this is
|
|
|
1798 -- the case of an operation of an untagged private type fulfilled
|
|
|
1799 -- by a tagged type that overrides an inherited dispatching
|
|
|
1800 -- operation, so we set the necessary dispatching attributes here.
|
|
|
1801
|
|
|
1802 if not Is_Dispatching_Operation (Old_Subp) then
|
|
|
1803
|
|
|
1804 -- If the untagged type has no discriminants, and the full
|
|
|
1805 -- view is constrained, there will be a spurious mismatch of
|
|
|
1806 -- subtypes on the controlling arguments, because the tagged
|
|
|
1807 -- type is the internal base type introduced in the derivation.
|
|
|
1808 -- Use the original type to verify conformance, rather than the
|
|
|
1809 -- base type.
|
|
|
1810
|
|
|
1811 if not Comes_From_Source (Tagged_Type)
|
|
|
1812 and then Has_Discriminants (Tagged_Type)
|
|
|
1813 then
|
|
|
1814 declare
|
|
|
1815 Formal : Entity_Id;
|
|
|
1816
|
|
|
1817 begin
|
|
|
1818 Formal := First_Formal (Old_Subp);
|
|
|
1819 while Present (Formal) loop
|
|
|
1820 if Tagged_Type = Base_Type (Etype (Formal)) then
|
|
|
1821 Tagged_Type := Etype (Formal);
|
|
|
1822 end if;
|
|
|
1823
|
|
|
1824 Next_Formal (Formal);
|
|
|
1825 end loop;
|
|
|
1826 end;
|
|
|
1827
|
|
|
1828 if Tagged_Type = Base_Type (Etype (Old_Subp)) then
|
|
|
1829 Tagged_Type := Etype (Old_Subp);
|
|
|
1830 end if;
|
|
|
1831 end if;
|
|
|
1832
|
|
|
1833 Check_Controlling_Formals (Tagged_Type, Old_Subp);
|
|
|
1834 Set_Is_Dispatching_Operation (Old_Subp, True);
|
|
|
1835 Set_DT_Position_Value (Old_Subp, No_Uint);
|
|
|
1836 end if;
|
|
|
1837
|
|
|
1838 -- If the old subprogram is an explicit renaming of some other
|
|
|
1839 -- entity, it is not overridden by the inherited subprogram.
|
|
|
1840 -- Otherwise, update its alias and other attributes.
|
|
|
1841
|
|
|
1842 if Present (Alias (Old_Subp))
|
|
|
1843 and then Nkind (Unit_Declaration_Node (Old_Subp)) /=
|
|
|
1844 N_Subprogram_Renaming_Declaration
|
|
|
1845 then
|
|
|
1846 Set_Alias (Old_Subp, Alias (Subp));
|
|
|
1847
|
|
|
1848 -- The derived subprogram should inherit the abstractness of
|
|
|
1849 -- the parent subprogram (except in the case of a function
|
|
|
1850 -- returning the type). This sets the abstractness properly
|
|
|
1851 -- for cases where a private extension may have inherited an
|
|
|
1852 -- abstract operation, but the full type is derived from a
|
|
|
1853 -- descendant type and inherits a nonabstract version.
|
|
|
1854
|
|
|
1855 if Etype (Subp) /= Tagged_Type then
|
|
|
1856 Set_Is_Abstract_Subprogram
|
|
|
1857 (Old_Subp, Is_Abstract_Subprogram (Alias (Subp)));
|
|
|
1858 end if;
|
|
|
1859 end if;
|
|
|
1860 end if;
|
|
|
1861 end if;
|
|
|
1862 end Check_Operation_From_Private_View;
|
|
|
1863
|
|
|
1864 --------------------------
|
|
|
1865 -- Find_Controlling_Arg --
|
|
|
1866 --------------------------
|
|
|
1867
|
|
|
1868 function Find_Controlling_Arg (N : Node_Id) return Node_Id is
|
|
|
1869 Orig_Node : constant Node_Id := Original_Node (N);
|
|
|
1870 Typ : Entity_Id;
|
|
|
1871
|
|
|
1872 begin
|
|
|
1873 if Nkind (Orig_Node) = N_Qualified_Expression then
|
|
|
1874 return Find_Controlling_Arg (Expression (Orig_Node));
|
|
|
1875 end if;
|
|
|
1876
|
|
|
1877 -- Dispatching on result case. If expansion is disabled, the node still
|
|
|
1878 -- has the structure of a function call. However, if the function name
|
|
|
1879 -- is an operator and the call was given in infix form, the original
|
|
|
1880 -- node has no controlling result and we must examine the current node.
|
|
|
1881
|
|
|
1882 if Nkind (N) = N_Function_Call
|
|
|
1883 and then Present (Controlling_Argument (N))
|
|
|
1884 and then Has_Controlling_Result (Entity (Name (N)))
|
|
|
1885 then
|
|
|
1886 return Controlling_Argument (N);
|
|
|
1887
|
|
|
1888 -- If expansion is enabled, the call may have been transformed into
|
|
|
1889 -- an indirect call, and we need to recover the original node.
|
|
|
1890
|
|
|
1891 elsif Nkind (Orig_Node) = N_Function_Call
|
|
|
1892 and then Present (Controlling_Argument (Orig_Node))
|
|
|
1893 and then Has_Controlling_Result (Entity (Name (Orig_Node)))
|
|
|
1894 then
|
|
|
1895 return Controlling_Argument (Orig_Node);
|
|
|
1896
|
|
|
1897 -- Type conversions are dynamically tagged if the target type, or its
|
|
|
1898 -- designated type, are classwide. An interface conversion expands into
|
|
|
1899 -- a dereference, so test must be performed on the original node.
|
|
|
1900
|
|
|
1901 elsif Nkind (Orig_Node) = N_Type_Conversion
|
|
|
1902 and then Nkind (N) = N_Explicit_Dereference
|
|
|
1903 and then Is_Controlling_Actual (N)
|
|
|
1904 then
|
|
|
1905 declare
|
|
|
1906 Target_Type : constant Entity_Id :=
|
|
|
1907 Entity (Subtype_Mark (Orig_Node));
|
|
|
1908
|
|
|
1909 begin
|
|
|
1910 if Is_Class_Wide_Type (Target_Type) then
|
|
|
1911 return N;
|
|
|
1912
|
|
|
1913 elsif Is_Access_Type (Target_Type)
|
|
|
1914 and then Is_Class_Wide_Type (Designated_Type (Target_Type))
|
|
|
1915 then
|
|
|
1916 return N;
|
|
|
1917
|
|
|
1918 else
|
|
|
1919 return Empty;
|
|
|
1920 end if;
|
|
|
1921 end;
|
|
|
1922
|
|
|
1923 -- Normal case
|
|
|
1924
|
|
|
1925 elsif Is_Controlling_Actual (N)
|
|
|
1926 or else
|
|
|
1927 (Nkind (Parent (N)) = N_Qualified_Expression
|
|
|
1928 and then Is_Controlling_Actual (Parent (N)))
|
|
|
1929 then
|
|
|
1930 Typ := Etype (N);
|
|
|
1931
|
|
|
1932 if Is_Access_Type (Typ) then
|
|
|
1933
|
|
|
1934 -- In the case of an Access attribute, use the type of the prefix,
|
|
|
1935 -- since in the case of an actual for an access parameter, the
|
|
|
1936 -- attribute's type may be of a specific designated type, even
|
|
|
1937 -- though the prefix type is class-wide.
|
|
|
1938
|
|
|
1939 if Nkind (N) = N_Attribute_Reference then
|
|
|
1940 Typ := Etype (Prefix (N));
|
|
|
1941
|
|
|
1942 -- An allocator is dispatching if the type of qualified expression
|
|
|
1943 -- is class_wide, in which case this is the controlling type.
|
|
|
1944
|
|
|
1945 elsif Nkind (Orig_Node) = N_Allocator
|
|
|
1946 and then Nkind (Expression (Orig_Node)) = N_Qualified_Expression
|
|
|
1947 then
|
|
|
1948 Typ := Etype (Expression (Orig_Node));
|
|
|
1949 else
|
|
|
1950 Typ := Designated_Type (Typ);
|
|
|
1951 end if;
|
|
|
1952 end if;
|
|
|
1953
|
|
|
1954 if Is_Class_Wide_Type (Typ)
|
|
|
1955 or else
|
|
|
1956 (Nkind (Parent (N)) = N_Qualified_Expression
|
|
|
1957 and then Is_Access_Type (Etype (N))
|
|
|
1958 and then Is_Class_Wide_Type (Designated_Type (Etype (N))))
|
|
|
1959 then
|
|
|
1960 return N;
|
|
|
1961 end if;
|
|
|
1962 end if;
|
|
|
1963
|
|
|
1964 return Empty;
|
|
|
1965 end Find_Controlling_Arg;
|
|
|
1966
|
|
|
1967 ---------------------------
|
|
|
1968 -- Find_Dispatching_Type --
|
|
|
1969 ---------------------------
|
|
|
1970
|
|
|
1971 function Find_Dispatching_Type (Subp : Entity_Id) return Entity_Id is
|
|
|
1972 A_Formal : Entity_Id;
|
|
|
1973 Formal : Entity_Id;
|
|
|
1974 Ctrl_Type : Entity_Id;
|
|
|
1975
|
|
|
1976 begin
|
|
|
1977 if Ekind_In (Subp, E_Function, E_Procedure)
|
|
|
1978 and then Present (DTC_Entity (Subp))
|
|
|
1979 then
|
|
|
1980 return Scope (DTC_Entity (Subp));
|
|
|
1981
|
|
|
1982 -- For subprograms internally generated by derivations of tagged types
|
|
|
1983 -- use the alias subprogram as a reference to locate the dispatching
|
|
|
1984 -- type of Subp.
|
|
|
1985
|
|
|
1986 elsif not Comes_From_Source (Subp)
|
|
|
1987 and then Present (Alias (Subp))
|
|
|
1988 and then Is_Dispatching_Operation (Alias (Subp))
|
|
|
1989 then
|
|
|
1990 if Ekind (Alias (Subp)) = E_Function
|
|
|
1991 and then Has_Controlling_Result (Alias (Subp))
|
|
|
1992 then
|
|
|
1993 return Check_Controlling_Type (Etype (Subp), Subp);
|
|
|
1994
|
|
|
1995 else
|
|
|
1996 Formal := First_Formal (Subp);
|
|
|
1997 A_Formal := First_Formal (Alias (Subp));
|
|
|
1998 while Present (A_Formal) loop
|
|
|
1999 if Is_Controlling_Formal (A_Formal) then
|
|
|
2000 return Check_Controlling_Type (Etype (Formal), Subp);
|
|
|
2001 end if;
|
|
|
2002
|
|
|
2003 Next_Formal (Formal);
|
|
|
2004 Next_Formal (A_Formal);
|
|
|
2005 end loop;
|
|
|
2006
|
|
|
2007 pragma Assert (False);
|
|
|
2008 return Empty;
|
|
|
2009 end if;
|
|
|
2010
|
|
|
2011 -- General case
|
|
|
2012
|
|
|
2013 else
|
|
|
2014 Formal := First_Formal (Subp);
|
|
|
2015 while Present (Formal) loop
|
|
|
2016 Ctrl_Type := Check_Controlling_Type (Etype (Formal), Subp);
|
|
|
2017
|
|
|
2018 if Present (Ctrl_Type) then
|
|
|
2019 return Ctrl_Type;
|
|
|
2020 end if;
|
|
|
2021
|
|
|
2022 Next_Formal (Formal);
|
|
|
2023 end loop;
|
|
|
2024
|
|
|
2025 -- The subprogram may also be dispatching on result
|
|
|
2026
|
|
|
2027 if Present (Etype (Subp)) then
|
|
|
2028 return Check_Controlling_Type (Etype (Subp), Subp);
|
|
|
2029 end if;
|
|
|
2030 end if;
|
|
|
2031
|
|
|
2032 pragma Assert (not Is_Dispatching_Operation (Subp));
|
|
|
2033 return Empty;
|
|
|
2034 end Find_Dispatching_Type;
|
|
|
2035
|
|
|
2036 --------------------------------------
|
|
|
2037 -- Find_Hidden_Overridden_Primitive --
|
|
|
2038 --------------------------------------
|
|
|
2039
|
|
|
2040 function Find_Hidden_Overridden_Primitive (S : Entity_Id) return Entity_Id
|
|
|
2041 is
|
|
|
2042 Tag_Typ : constant Entity_Id := Find_Dispatching_Type (S);
|
|
|
2043 Elmt : Elmt_Id;
|
|
|
2044 Orig_Prim : Entity_Id;
|
|
|
2045 Prim : Entity_Id;
|
|
|
2046 Vis_List : Elist_Id;
|
|
|
2047
|
|
|
2048 begin
|
|
|
2049 -- This Ada 2012 rule applies only for type extensions or private
|
|
|
2050 -- extensions, where the parent type is not in a parent unit, and
|
|
|
2051 -- where an operation is never declared but still inherited.
|
|
|
2052
|
|
|
2053 if No (Tag_Typ)
|
|
|
2054 or else not Is_Record_Type (Tag_Typ)
|
|
|
2055 or else Etype (Tag_Typ) = Tag_Typ
|
|
|
2056 or else In_Open_Scopes (Scope (Etype (Tag_Typ)))
|
|
|
2057 then
|
|
|
2058 return Empty;
|
|
|
2059 end if;
|
|
|
2060
|
|
|
2061 -- Collect the list of visible ancestor of the tagged type
|
|
|
2062
|
|
|
2063 Vis_List := Visible_Ancestors (Tag_Typ);
|
|
|
2064
|
|
|
2065 Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
|
|
|
2066 while Present (Elmt) loop
|
|
|
2067 Prim := Node (Elmt);
|
|
|
2068
|
|
|
2069 -- Find an inherited hidden dispatching primitive with the name of S
|
|
|
2070 -- and a type-conformant profile.
|
|
|
2071
|
|
|
2072 if Present (Alias (Prim))
|
|
|
2073 and then Is_Hidden (Alias (Prim))
|
|
|
2074 and then Find_Dispatching_Type (Alias (Prim)) /= Tag_Typ
|
|
|
2075 and then Primitive_Names_Match (S, Prim)
|
|
|
2076 and then Type_Conformant (S, Prim)
|
|
|
2077 then
|
|
|
2078 declare
|
|
|
2079 Vis_Ancestor : Elmt_Id;
|
|
|
2080 Elmt : Elmt_Id;
|
|
|
2081
|
|
|
2082 begin
|
|
|
2083 -- The original corresponding operation of Prim must be an
|
|
|
2084 -- operation of a visible ancestor of the dispatching type S,
|
|
|
2085 -- and the original corresponding operation of S2 must be
|
|
|
2086 -- visible.
|
|
|
2087
|
|
|
2088 Orig_Prim := Original_Corresponding_Operation (Prim);
|
|
|
2089
|
|
|
2090 if Orig_Prim /= Prim
|
|
|
2091 and then Is_Immediately_Visible (Orig_Prim)
|
|
|
2092 then
|
|
|
2093 Vis_Ancestor := First_Elmt (Vis_List);
|
|
|
2094 while Present (Vis_Ancestor) loop
|
|
|
2095 Elmt :=
|
|
|
2096 First_Elmt (Primitive_Operations (Node (Vis_Ancestor)));
|
|
|
2097 while Present (Elmt) loop
|
|
|
2098 if Node (Elmt) = Orig_Prim then
|
|
|
2099 Set_Overridden_Operation (S, Prim);
|
|
|
2100 Set_Alias (Prim, Orig_Prim);
|
|
|
2101 return Prim;
|
|
|
2102 end if;
|
|
|
2103
|
|
|
2104 Next_Elmt (Elmt);
|
|
|
2105 end loop;
|
|
|
2106
|
|
|
2107 Next_Elmt (Vis_Ancestor);
|
|
|
2108 end loop;
|
|
|
2109 end if;
|
|
|
2110 end;
|
|
|
2111 end if;
|
|
|
2112
|
|
|
2113 Next_Elmt (Elmt);
|
|
|
2114 end loop;
|
|
|
2115
|
|
|
2116 return Empty;
|
|
|
2117 end Find_Hidden_Overridden_Primitive;
|
|
|
2118
|
|
|
2119 ---------------------------------------
|
|
|
2120 -- Find_Primitive_Covering_Interface --
|
|
|
2121 ---------------------------------------
|
|
|
2122
|
|
|
2123 function Find_Primitive_Covering_Interface
|
|
|
2124 (Tagged_Type : Entity_Id;
|
|
|
2125 Iface_Prim : Entity_Id) return Entity_Id
|
|
|
2126 is
|
|
|
2127 E : Entity_Id;
|
|
|
2128 El : Elmt_Id;
|
|
|
2129
|
|
|
2130 begin
|
|
|
2131 pragma Assert (Is_Interface (Find_Dispatching_Type (Iface_Prim))
|
|
|
2132 or else (Present (Alias (Iface_Prim))
|
|
|
2133 and then
|
|
|
2134 Is_Interface
|
|
|
2135 (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
|
|
|
2136
|
|
|
2137 -- Search in the homonym chain. Done to speed up locating visible
|
|
|
2138 -- entities and required to catch primitives associated with the partial
|
|
|
2139 -- view of private types when processing the corresponding full view.
|
|
|
2140
|
|
|
2141 E := Current_Entity (Iface_Prim);
|
|
|
2142 while Present (E) loop
|
|
|
2143 if Is_Subprogram (E)
|
|
|
2144 and then Is_Dispatching_Operation (E)
|
|
|
2145 and then Is_Interface_Conformant (Tagged_Type, Iface_Prim, E)
|
|
|
2146 then
|
|
|
2147 return E;
|
|
|
2148 end if;
|
|
|
2149
|
|
|
2150 E := Homonym (E);
|
|
|
2151 end loop;
|
|
|
2152
|
|
|
2153 -- Search in the list of primitives of the type. Required to locate
|
|
|
2154 -- the covering primitive if the covering primitive is not visible
|
|
|
2155 -- (for example, non-visible inherited primitive of private type).
|
|
|
2156
|
|
|
2157 El := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
|
2158 while Present (El) loop
|
|
|
2159 E := Node (El);
|
|
|
2160
|
|
|
2161 -- Keep separate the management of internal entities that link
|
|
|
2162 -- primitives with interface primitives from tagged type primitives.
|
|
|
2163
|
|
|
2164 if No (Interface_Alias (E)) then
|
|
|
2165 if Present (Alias (E)) then
|
|
|
2166
|
|
|
2167 -- This interface primitive has not been covered yet
|
|
|
2168
|
|
|
2169 if Alias (E) = Iface_Prim then
|
|
|
2170 return E;
|
|
|
2171
|
|
|
2172 -- The covering primitive was inherited
|
|
|
2173
|
|
|
2174 elsif Overridden_Operation (Ultimate_Alias (E))
|
|
|
2175 = Iface_Prim
|
|
|
2176 then
|
|
|
2177 return E;
|
|
|
2178 end if;
|
|
|
2179 end if;
|
|
|
2180
|
|
|
2181 -- Check if E covers the interface primitive (includes case in
|
|
|
2182 -- which E is an inherited private primitive).
|
|
|
2183
|
|
|
2184 if Is_Interface_Conformant (Tagged_Type, Iface_Prim, E) then
|
|
|
2185 return E;
|
|
|
2186 end if;
|
|
|
2187
|
|
|
2188 -- Use the internal entity that links the interface primitive with
|
|
|
2189 -- the covering primitive to locate the entity.
|
|
|
2190
|
|
|
2191 elsif Interface_Alias (E) = Iface_Prim then
|
|
|
2192 return Alias (E);
|
|
|
2193 end if;
|
|
|
2194
|
|
|
2195 Next_Elmt (El);
|
|
|
2196 end loop;
|
|
|
2197
|
|
|
2198 -- Not found
|
|
|
2199
|
|
|
2200 return Empty;
|
|
|
2201 end Find_Primitive_Covering_Interface;
|
|
|
2202
|
|
|
2203 ---------------------------
|
|
131
|
2204 -- Inheritance_Utilities --
|
|
|
2205 ---------------------------
|
|
|
2206
|
|
|
2207 package body Inheritance_Utilities is
|
|
|
2208
|
|
|
2209 ---------------------------
|
|
|
2210 -- Inherited_Subprograms --
|
|
|
2211 ---------------------------
|
|
|
2212
|
|
|
2213 function Inherited_Subprograms
|
|
|
2214 (S : Entity_Id;
|
|
|
2215 No_Interfaces : Boolean := False;
|
|
|
2216 Interfaces_Only : Boolean := False;
|
|
|
2217 One_Only : Boolean := False) return Subprogram_List
|
|
|
2218 is
|
|
|
2219 Result : Subprogram_List (1 .. 6000);
|
|
|
2220 -- 6000 here is intended to be infinity. We could use an expandable
|
|
|
2221 -- table, but it would be awfully heavy, and there is no way that we
|
|
|
2222 -- could reasonably exceed this value.
|
|
|
2223
|
|
|
2224 N : Nat := 0;
|
|
|
2225 -- Number of entries in Result
|
|
|
2226
|
|
|
2227 Parent_Op : Entity_Id;
|
|
|
2228 -- Traverses the Overridden_Operation chain
|
|
|
2229
|
|
|
2230 procedure Store_IS (E : Entity_Id);
|
|
|
2231 -- Stores E in Result if not already stored
|
|
|
2232
|
|
|
2233 --------------
|
|
|
2234 -- Store_IS --
|
|
|
2235 --------------
|
|
|
2236
|
|
|
2237 procedure Store_IS (E : Entity_Id) is
|
|
|
2238 begin
|
|
|
2239 for J in 1 .. N loop
|
|
|
2240 if E = Result (J) then
|
|
|
2241 return;
|
|
|
2242 end if;
|
|
|
2243 end loop;
|
|
|
2244
|
|
|
2245 N := N + 1;
|
|
|
2246 Result (N) := E;
|
|
|
2247 end Store_IS;
|
|
|
2248
|
|
|
2249 -- Start of processing for Inherited_Subprograms
|
|
|
2250
|
|
|
2251 begin
|
|
|
2252 pragma Assert (not (No_Interfaces and Interfaces_Only));
|
|
|
2253
|
|
|
2254 -- When used from backends, visibility can be handled differently
|
|
|
2255 -- resulting in no dispatching type being found.
|
|
|
2256
|
|
|
2257 if Present (S)
|
|
|
2258 and then Is_Dispatching_Operation (S)
|
|
|
2259 and then Present (Find_DT (S))
|
|
|
2260 then
|
|
|
2261 -- Deal with direct inheritance
|
|
|
2262
|
|
|
2263 if not Interfaces_Only then
|
|
|
2264 Parent_Op := S;
|
|
|
2265 loop
|
|
|
2266 Parent_Op := Overridden_Operation (Parent_Op);
|
|
|
2267 exit when No (Parent_Op)
|
|
|
2268 or else (No_Interfaces
|
|
|
2269 and then Is_Interface (Find_DT (Parent_Op)));
|
|
|
2270
|
|
|
2271 if Is_Subprogram_Or_Generic_Subprogram (Parent_Op) then
|
|
|
2272 Store_IS (Parent_Op);
|
|
|
2273
|
|
|
2274 if One_Only then
|
|
|
2275 goto Done;
|
|
|
2276 end if;
|
|
|
2277 end if;
|
|
|
2278 end loop;
|
|
|
2279 end if;
|
|
|
2280
|
|
|
2281 -- Now deal with interfaces
|
|
|
2282
|
|
|
2283 if not No_Interfaces then
|
|
|
2284 declare
|
|
|
2285 Tag_Typ : Entity_Id;
|
|
|
2286 Prim : Entity_Id;
|
|
|
2287 Elmt : Elmt_Id;
|
|
|
2288
|
|
|
2289 begin
|
|
|
2290 Tag_Typ := Find_DT (S);
|
|
|
2291
|
|
|
2292 -- In the presence of limited views there may be no visible
|
|
|
2293 -- dispatching type. Primitives will be inherited when non-
|
|
|
2294 -- limited view is frozen.
|
|
|
2295
|
|
|
2296 if No (Tag_Typ) then
|
|
|
2297 return Result (1 .. 0);
|
|
|
2298 end if;
|
|
|
2299
|
|
|
2300 if Is_Concurrent_Type (Tag_Typ) then
|
|
|
2301 Tag_Typ := Corresponding_Record_Type (Tag_Typ);
|
|
|
2302 end if;
|
|
|
2303
|
|
|
2304 -- Search primitive operations of dispatching type
|
|
|
2305
|
|
|
2306 if Present (Tag_Typ)
|
|
|
2307 and then Present (Primitive_Operations (Tag_Typ))
|
|
|
2308 then
|
|
|
2309 Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
|
|
|
2310 while Present (Elmt) loop
|
|
|
2311 Prim := Node (Elmt);
|
|
|
2312
|
|
|
2313 -- The following test eliminates some odd cases in
|
|
|
2314 -- which Ekind (Prim) is Void, to be investigated
|
|
|
2315 -- further ???
|
|
|
2316
|
|
|
2317 if not Is_Subprogram_Or_Generic_Subprogram (Prim) then
|
|
|
2318 null;
|
|
|
2319
|
|
|
2320 -- For [generic] subprogram, look at interface
|
|
|
2321 -- alias.
|
|
|
2322
|
|
|
2323 elsif Present (Interface_Alias (Prim))
|
|
|
2324 and then Alias (Prim) = S
|
|
|
2325 then
|
|
|
2326 -- We have found a primitive covered by S
|
|
|
2327
|
|
|
2328 Store_IS (Interface_Alias (Prim));
|
|
|
2329
|
|
|
2330 if One_Only then
|
|
|
2331 goto Done;
|
|
|
2332 end if;
|
|
|
2333 end if;
|
|
|
2334
|
|
|
2335 Next_Elmt (Elmt);
|
|
|
2336 end loop;
|
|
|
2337 end if;
|
|
|
2338 end;
|
|
|
2339 end if;
|
|
|
2340 end if;
|
|
|
2341
|
|
|
2342 <<Done>>
|
|
|
2343
|
|
|
2344 return Result (1 .. N);
|
|
|
2345 end Inherited_Subprograms;
|
|
|
2346
|
|
|
2347 ------------------------------
|
|
|
2348 -- Is_Overriding_Subprogram --
|
|
|
2349 ------------------------------
|
|
|
2350
|
|
|
2351 function Is_Overriding_Subprogram (E : Entity_Id) return Boolean is
|
|
|
2352 Inherited : constant Subprogram_List :=
|
|
|
2353 Inherited_Subprograms (E, One_Only => True);
|
|
|
2354 begin
|
|
|
2355 return Inherited'Length > 0;
|
|
|
2356 end Is_Overriding_Subprogram;
|
|
|
2357 end Inheritance_Utilities;
|
|
|
2358
|
|
|
2359 --------------------------------
|
|
|
2360 -- Inheritance_Utilities_Inst --
|
|
|
2361 --------------------------------
|
|
|
2362
|
|
|
2363 package Inheritance_Utilities_Inst is new
|
|
|
2364 Inheritance_Utilities (Find_Dispatching_Type);
|
|
|
2365
|
|
|
2366 ---------------------------
|
|
111
|
2367 -- Inherited_Subprograms --
|
|
|
2368 ---------------------------
|
|
|
2369
|
|
|
2370 function Inherited_Subprograms
|
|
|
2371 (S : Entity_Id;
|
|
|
2372 No_Interfaces : Boolean := False;
|
|
|
2373 Interfaces_Only : Boolean := False;
|
|
131
|
2374 One_Only : Boolean := False) return Subprogram_List renames
|
|
|
2375 Inheritance_Utilities_Inst.Inherited_Subprograms;
|
|
111
|
2376
|
|
|
2377 ---------------------------
|
|
|
2378 -- Is_Dynamically_Tagged --
|
|
|
2379 ---------------------------
|
|
|
2380
|
|
|
2381 function Is_Dynamically_Tagged (N : Node_Id) return Boolean is
|
|
|
2382 begin
|
|
|
2383 if Nkind (N) = N_Error then
|
|
|
2384 return False;
|
|
|
2385
|
|
|
2386 elsif Present (Find_Controlling_Arg (N)) then
|
|
|
2387 return True;
|
|
|
2388
|
|
|
2389 -- Special cases: entities, and calls that dispatch on result
|
|
|
2390
|
|
|
2391 elsif Is_Entity_Name (N) then
|
|
|
2392 return Is_Class_Wide_Type (Etype (N));
|
|
|
2393
|
|
|
2394 elsif Nkind (N) = N_Function_Call
|
|
|
2395 and then Is_Class_Wide_Type (Etype (N))
|
|
|
2396 then
|
|
|
2397 return True;
|
|
|
2398
|
|
|
2399 -- Otherwise check whether call has controlling argument
|
|
|
2400
|
|
|
2401 else
|
|
|
2402 return False;
|
|
|
2403 end if;
|
|
|
2404 end Is_Dynamically_Tagged;
|
|
|
2405
|
|
|
2406 ---------------------------------
|
|
|
2407 -- Is_Null_Interface_Primitive --
|
|
|
2408 ---------------------------------
|
|
|
2409
|
|
|
2410 function Is_Null_Interface_Primitive (E : Entity_Id) return Boolean is
|
|
|
2411 begin
|
|
|
2412 return Comes_From_Source (E)
|
|
|
2413 and then Is_Dispatching_Operation (E)
|
|
|
2414 and then Ekind (E) = E_Procedure
|
|
|
2415 and then Null_Present (Parent (E))
|
|
|
2416 and then Is_Interface (Find_Dispatching_Type (E));
|
|
|
2417 end Is_Null_Interface_Primitive;
|
|
|
2418
|
|
|
2419 -----------------------------------
|
|
|
2420 -- Is_Inherited_Public_Operation --
|
|
|
2421 -----------------------------------
|
|
|
2422
|
|
|
2423 function Is_Inherited_Public_Operation (Op : Entity_Id) return Boolean is
|
|
|
2424 Pack_Decl : Node_Id;
|
|
131
|
2425 Prim : Entity_Id := Op;
|
|
|
2426 Scop : Entity_Id := Prim;
|
|
111
|
2427
|
|
|
2428 begin
|
|
131
|
2429 -- Locate the ultimate non-hidden alias entity
|
|
|
2430
|
|
|
2431 while Present (Alias (Prim)) and then not Is_Hidden (Alias (Prim)) loop
|
|
|
2432 pragma Assert (Alias (Prim) /= Prim);
|
|
|
2433 Prim := Alias (Prim);
|
|
|
2434 Scop := Scope (Prim);
|
|
|
2435 end loop;
|
|
|
2436
|
|
111
|
2437 if Comes_From_Source (Prim) and then Ekind (Scop) = E_Package then
|
|
|
2438 Pack_Decl := Unit_Declaration_Node (Scop);
|
|
131
|
2439
|
|
|
2440 return
|
|
|
2441 Nkind (Pack_Decl) = N_Package_Declaration
|
|
|
2442 and then List_Containing (Unit_Declaration_Node (Prim)) =
|
|
|
2443 Visible_Declarations (Specification (Pack_Decl));
|
|
111
|
2444
|
|
|
2445 else
|
|
|
2446 return False;
|
|
|
2447 end if;
|
|
|
2448 end Is_Inherited_Public_Operation;
|
|
|
2449
|
|
|
2450 ------------------------------
|
|
|
2451 -- Is_Overriding_Subprogram --
|
|
|
2452 ------------------------------
|
|
|
2453
|
|
131
|
2454 function Is_Overriding_Subprogram (E : Entity_Id) return Boolean renames
|
|
|
2455 Inheritance_Utilities_Inst.Is_Overriding_Subprogram;
|
|
111
|
2456
|
|
|
2457 --------------------------
|
|
|
2458 -- Is_Tag_Indeterminate --
|
|
|
2459 --------------------------
|
|
|
2460
|
|
|
2461 function Is_Tag_Indeterminate (N : Node_Id) return Boolean is
|
|
|
2462 Nam : Entity_Id;
|
|
|
2463 Actual : Node_Id;
|
|
|
2464 Orig_Node : constant Node_Id := Original_Node (N);
|
|
|
2465
|
|
|
2466 begin
|
|
|
2467 if Nkind (Orig_Node) = N_Function_Call
|
|
|
2468 and then Is_Entity_Name (Name (Orig_Node))
|
|
|
2469 then
|
|
|
2470 Nam := Entity (Name (Orig_Node));
|
|
|
2471
|
|
|
2472 if not Has_Controlling_Result (Nam) then
|
|
|
2473 return False;
|
|
|
2474
|
|
|
2475 -- The function may have a controlling result, but if the return type
|
|
|
2476 -- is not visibly tagged, then this is not tag-indeterminate.
|
|
|
2477
|
|
|
2478 elsif Is_Access_Type (Etype (Nam))
|
|
|
2479 and then not Is_Tagged_Type (Designated_Type (Etype (Nam)))
|
|
|
2480 then
|
|
|
2481 return False;
|
|
|
2482
|
|
|
2483 -- An explicit dereference means that the call has already been
|
|
|
2484 -- expanded and there is no tag to propagate.
|
|
|
2485
|
|
|
2486 elsif Nkind (N) = N_Explicit_Dereference then
|
|
|
2487 return False;
|
|
|
2488
|
|
|
2489 -- If there are no actuals, the call is tag-indeterminate
|
|
|
2490
|
|
|
2491 elsif No (Parameter_Associations (Orig_Node)) then
|
|
|
2492 return True;
|
|
|
2493
|
|
|
2494 else
|
|
|
2495 Actual := First_Actual (Orig_Node);
|
|
|
2496 while Present (Actual) loop
|
|
|
2497 if Is_Controlling_Actual (Actual)
|
|
|
2498 and then not Is_Tag_Indeterminate (Actual)
|
|
|
2499 then
|
|
|
2500 -- One operand is dispatching
|
|
|
2501
|
|
|
2502 return False;
|
|
|
2503 end if;
|
|
|
2504
|
|
|
2505 Next_Actual (Actual);
|
|
|
2506 end loop;
|
|
|
2507
|
|
|
2508 return True;
|
|
|
2509 end if;
|
|
|
2510
|
|
|
2511 elsif Nkind (Orig_Node) = N_Qualified_Expression then
|
|
|
2512 return Is_Tag_Indeterminate (Expression (Orig_Node));
|
|
|
2513
|
|
|
2514 -- Case of a call to the Input attribute (possibly rewritten), which is
|
|
|
2515 -- always tag-indeterminate except when its prefix is a Class attribute.
|
|
|
2516
|
|
|
2517 elsif Nkind (Orig_Node) = N_Attribute_Reference
|
|
|
2518 and then
|
|
|
2519 Get_Attribute_Id (Attribute_Name (Orig_Node)) = Attribute_Input
|
|
|
2520 and then Nkind (Prefix (Orig_Node)) /= N_Attribute_Reference
|
|
|
2521 then
|
|
|
2522 return True;
|
|
|
2523
|
|
|
2524 -- In Ada 2005, a function that returns an anonymous access type can be
|
|
|
2525 -- dispatching, and the dereference of a call to such a function can
|
|
|
2526 -- also be tag-indeterminate if the call itself is.
|
|
|
2527
|
|
|
2528 elsif Nkind (Orig_Node) = N_Explicit_Dereference
|
|
|
2529 and then Ada_Version >= Ada_2005
|
|
|
2530 then
|
|
|
2531 return Is_Tag_Indeterminate (Prefix (Orig_Node));
|
|
|
2532
|
|
|
2533 else
|
|
|
2534 return False;
|
|
|
2535 end if;
|
|
|
2536 end Is_Tag_Indeterminate;
|
|
|
2537
|
|
|
2538 ------------------------------------
|
|
|
2539 -- Override_Dispatching_Operation --
|
|
|
2540 ------------------------------------
|
|
|
2541
|
|
|
2542 procedure Override_Dispatching_Operation
|
|
|
2543 (Tagged_Type : Entity_Id;
|
|
|
2544 Prev_Op : Entity_Id;
|
|
|
2545 New_Op : Entity_Id;
|
|
|
2546 Is_Wrapper : Boolean := False)
|
|
|
2547 is
|
|
|
2548 Elmt : Elmt_Id;
|
|
|
2549 Prim : Node_Id;
|
|
|
2550
|
|
|
2551 begin
|
|
|
2552 -- Diagnose failure to match No_Return in parent (Ada-2005, AI-414, but
|
|
|
2553 -- we do it unconditionally in Ada 95 now, since this is our pragma).
|
|
|
2554
|
|
|
2555 if No_Return (Prev_Op) and then not No_Return (New_Op) then
|
|
|
2556 Error_Msg_N ("procedure & must have No_Return pragma", New_Op);
|
|
|
2557 Error_Msg_N ("\since overridden procedure has No_Return", New_Op);
|
|
|
2558 end if;
|
|
|
2559
|
|
|
2560 -- If there is no previous operation to override, the type declaration
|
|
|
2561 -- was malformed, and an error must have been emitted already.
|
|
|
2562
|
|
|
2563 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
|
2564 while Present (Elmt) and then Node (Elmt) /= Prev_Op loop
|
|
|
2565 Next_Elmt (Elmt);
|
|
|
2566 end loop;
|
|
|
2567
|
|
|
2568 if No (Elmt) then
|
|
|
2569 return;
|
|
|
2570 end if;
|
|
|
2571
|
|
|
2572 -- The location of entities that come from source in the list of
|
|
|
2573 -- primitives of the tagged type must follow their order of occurrence
|
|
|
2574 -- in the sources to fulfill the C++ ABI. If the overridden entity is a
|
|
|
2575 -- primitive of an interface that is not implemented by the parents of
|
|
|
2576 -- this tagged type (that is, it is an alias of an interface primitive
|
|
|
2577 -- generated by Derive_Interface_Progenitors), then we must append the
|
|
|
2578 -- new entity at the end of the list of primitives.
|
|
|
2579
|
|
|
2580 if Present (Alias (Prev_Op))
|
|
|
2581 and then Etype (Tagged_Type) /= Tagged_Type
|
|
|
2582 and then Is_Interface (Find_Dispatching_Type (Alias (Prev_Op)))
|
|
|
2583 and then not Is_Ancestor (Find_Dispatching_Type (Alias (Prev_Op)),
|
|
|
2584 Tagged_Type, Use_Full_View => True)
|
|
|
2585 and then not Implements_Interface
|
|
|
2586 (Etype (Tagged_Type),
|
|
|
2587 Find_Dispatching_Type (Alias (Prev_Op)))
|
|
|
2588 then
|
|
|
2589 Remove_Elmt (Primitive_Operations (Tagged_Type), Elmt);
|
|
131
|
2590 Add_Dispatching_Operation (Tagged_Type, New_Op);
|
|
111
|
2591
|
|
|
2592 -- The new primitive replaces the overridden entity. Required to ensure
|
|
|
2593 -- that overriding primitive is assigned the same dispatch table slot.
|
|
|
2594
|
|
|
2595 else
|
|
|
2596 Replace_Elmt (Elmt, New_Op);
|
|
|
2597 end if;
|
|
|
2598
|
|
|
2599 if Ada_Version >= Ada_2005 and then Has_Interfaces (Tagged_Type) then
|
|
|
2600
|
|
|
2601 -- Ada 2005 (AI-251): Update the attribute alias of all the aliased
|
|
|
2602 -- entities of the overridden primitive to reference New_Op, and
|
|
|
2603 -- also propagate the proper value of Is_Abstract_Subprogram. Verify
|
|
|
2604 -- that the new operation is subtype conformant with the interface
|
|
|
2605 -- operations that it implements (for operations inherited from the
|
|
|
2606 -- parent itself, this check is made when building the derived type).
|
|
|
2607
|
|
|
2608 -- Note: This code is executed with internally generated wrappers of
|
|
|
2609 -- functions with controlling result and late overridings.
|
|
|
2610
|
|
|
2611 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
|
2612 while Present (Elmt) loop
|
|
|
2613 Prim := Node (Elmt);
|
|
|
2614
|
|
|
2615 if Prim = New_Op then
|
|
|
2616 null;
|
|
|
2617
|
|
|
2618 -- Note: The check on Is_Subprogram protects the frontend against
|
|
|
2619 -- reading attributes in entities that are not yet fully decorated
|
|
|
2620
|
|
|
2621 elsif Is_Subprogram (Prim)
|
|
|
2622 and then Present (Interface_Alias (Prim))
|
|
|
2623 and then Alias (Prim) = Prev_Op
|
|
|
2624 then
|
|
|
2625 Set_Alias (Prim, New_Op);
|
|
|
2626
|
|
|
2627 -- No further decoration needed yet for internally generated
|
|
|
2628 -- wrappers of controlling functions since (at this stage)
|
|
|
2629 -- they are not yet decorated.
|
|
|
2630
|
|
|
2631 if not Is_Wrapper then
|
|
|
2632 Check_Subtype_Conformant (New_Op, Prim);
|
|
|
2633
|
|
|
2634 Set_Is_Abstract_Subprogram (Prim,
|
|
|
2635 Is_Abstract_Subprogram (New_Op));
|
|
|
2636
|
|
|
2637 -- Ensure that this entity will be expanded to fill the
|
|
|
2638 -- corresponding entry in its dispatch table.
|
|
|
2639
|
|
|
2640 if not Is_Abstract_Subprogram (Prim) then
|
|
|
2641 Set_Has_Delayed_Freeze (Prim);
|
|
|
2642 end if;
|
|
|
2643 end if;
|
|
|
2644 end if;
|
|
|
2645
|
|
|
2646 Next_Elmt (Elmt);
|
|
|
2647 end loop;
|
|
|
2648 end if;
|
|
|
2649
|
|
|
2650 if (not Is_Package_Or_Generic_Package (Current_Scope))
|
|
|
2651 or else not In_Private_Part (Current_Scope)
|
|
|
2652 then
|
|
|
2653 -- Not a private primitive
|
|
|
2654
|
|
|
2655 null;
|
|
|
2656
|
|
|
2657 else pragma Assert (Is_Inherited_Operation (Prev_Op));
|
|
|
2658
|
|
|
2659 -- Make the overriding operation into an alias of the implicit one.
|
|
|
2660 -- In this fashion a call from outside ends up calling the new body
|
|
|
2661 -- even if non-dispatching, and a call from inside calls the over-
|
|
|
2662 -- riding operation because it hides the implicit one. To indicate
|
|
|
2663 -- that the body of Prev_Op is never called, set its dispatch table
|
|
|
2664 -- entity to Empty. If the overridden operation has a dispatching
|
|
|
2665 -- result, so does the overriding one.
|
|
|
2666
|
|
|
2667 Set_Alias (Prev_Op, New_Op);
|
|
|
2668 Set_DTC_Entity (Prev_Op, Empty);
|
|
|
2669 Set_Has_Controlling_Result (New_Op, Has_Controlling_Result (Prev_Op));
|
|
|
2670 return;
|
|
|
2671 end if;
|
|
|
2672 end Override_Dispatching_Operation;
|
|
|
2673
|
|
|
2674 -------------------
|
|
|
2675 -- Propagate_Tag --
|
|
|
2676 -------------------
|
|
|
2677
|
|
|
2678 procedure Propagate_Tag (Control : Node_Id; Actual : Node_Id) is
|
|
|
2679 Call_Node : Node_Id;
|
|
|
2680 Arg : Node_Id;
|
|
|
2681
|
|
|
2682 begin
|
|
|
2683 if Nkind (Actual) = N_Function_Call then
|
|
|
2684 Call_Node := Actual;
|
|
|
2685
|
|
|
2686 elsif Nkind (Actual) = N_Identifier
|
|
|
2687 and then Nkind (Original_Node (Actual)) = N_Function_Call
|
|
|
2688 then
|
|
|
2689 -- Call rewritten as object declaration when stack-checking is
|
|
|
2690 -- enabled. Propagate tag to expression in declaration, which is
|
|
|
2691 -- original call.
|
|
|
2692
|
|
|
2693 Call_Node := Expression (Parent (Entity (Actual)));
|
|
|
2694
|
|
|
2695 -- Ada 2005: If this is a dereference of a call to a function with a
|
|
|
2696 -- dispatching access-result, the tag is propagated when the dereference
|
|
|
2697 -- itself is expanded (see exp_ch6.adb) and there is nothing else to do.
|
|
|
2698
|
|
|
2699 elsif Nkind (Actual) = N_Explicit_Dereference
|
|
|
2700 and then Nkind (Original_Node (Prefix (Actual))) = N_Function_Call
|
|
|
2701 then
|
|
|
2702 return;
|
|
|
2703
|
|
|
2704 -- When expansion is suppressed, an unexpanded call to 'Input can occur,
|
|
|
2705 -- and in that case we can simply return.
|
|
|
2706
|
|
|
2707 elsif Nkind (Actual) = N_Attribute_Reference then
|
|
|
2708 pragma Assert (Attribute_Name (Actual) = Name_Input);
|
|
|
2709
|
|
|
2710 return;
|
|
|
2711
|
|
|
2712 -- Only other possibilities are parenthesized or qualified expression,
|
|
|
2713 -- or an expander-generated unchecked conversion of a function call to
|
|
|
2714 -- a stream Input attribute.
|
|
|
2715
|
|
|
2716 else
|
|
|
2717 Call_Node := Expression (Actual);
|
|
|
2718 end if;
|
|
|
2719
|
|
|
2720 -- No action needed if the call has been already expanded
|
|
|
2721
|
|
|
2722 if Is_Expanded_Dispatching_Call (Call_Node) then
|
|
|
2723 return;
|
|
|
2724 end if;
|
|
|
2725
|
|
|
2726 -- Do not set the Controlling_Argument if already set. This happens in
|
|
|
2727 -- the special case of _Input (see Exp_Attr, case Input).
|
|
|
2728
|
|
|
2729 if No (Controlling_Argument (Call_Node)) then
|
|
|
2730 Set_Controlling_Argument (Call_Node, Control);
|
|
|
2731 end if;
|
|
|
2732
|
|
|
2733 Arg := First_Actual (Call_Node);
|
|
|
2734 while Present (Arg) loop
|
|
|
2735 if Is_Tag_Indeterminate (Arg) then
|
|
|
2736 Propagate_Tag (Control, Arg);
|
|
|
2737 end if;
|
|
|
2738
|
|
|
2739 Next_Actual (Arg);
|
|
|
2740 end loop;
|
|
|
2741
|
|
|
2742 -- Expansion of dispatching calls is suppressed on VM targets, because
|
|
|
2743 -- the VM back-ends directly handle the generation of dispatching calls
|
|
|
2744 -- and would have to undo any expansion to an indirect call.
|
|
|
2745
|
|
|
2746 if Tagged_Type_Expansion then
|
|
|
2747 declare
|
|
|
2748 Call_Typ : constant Entity_Id := Etype (Call_Node);
|
|
|
2749
|
|
|
2750 begin
|
|
|
2751 Expand_Dispatching_Call (Call_Node);
|
|
|
2752
|
|
|
2753 -- If the controlling argument is an interface type and the type
|
|
|
2754 -- of Call_Node differs then we must add an implicit conversion to
|
|
|
2755 -- force displacement of the pointer to the object to reference
|
|
|
2756 -- the secondary dispatch table of the interface.
|
|
|
2757
|
|
|
2758 if Is_Interface (Etype (Control))
|
|
|
2759 and then Etype (Control) /= Call_Typ
|
|
|
2760 then
|
|
|
2761 -- Cannot use Convert_To because the previous call to
|
|
|
2762 -- Expand_Dispatching_Call leaves decorated the Call_Node
|
|
|
2763 -- with the type of Control.
|
|
|
2764
|
|
|
2765 Rewrite (Call_Node,
|
|
|
2766 Make_Type_Conversion (Sloc (Call_Node),
|
|
|
2767 Subtype_Mark =>
|
|
|
2768 New_Occurrence_Of (Etype (Control), Sloc (Call_Node)),
|
|
|
2769 Expression => Relocate_Node (Call_Node)));
|
|
|
2770 Set_Etype (Call_Node, Etype (Control));
|
|
|
2771 Set_Analyzed (Call_Node);
|
|
|
2772
|
|
|
2773 Expand_Interface_Conversion (Call_Node);
|
|
|
2774 end if;
|
|
|
2775 end;
|
|
|
2776
|
|
|
2777 -- Expansion of a dispatching call results in an indirect call, which in
|
|
|
2778 -- turn causes current values to be killed (see Resolve_Call), so on VM
|
|
|
2779 -- targets we do the call here to ensure consistent warnings between VM
|
|
|
2780 -- and non-VM targets.
|
|
|
2781
|
|
|
2782 else
|
|
|
2783 Kill_Current_Values;
|
|
|
2784 end if;
|
|
|
2785 end Propagate_Tag;
|
|
|
2786
|
|
|
2787 end Sem_Disp;
|
