1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- I N L I N E -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2019, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26-- This module handles four kinds of inlining activity: 27 28-- a) Instantiation of generic bodies. This is done unconditionally, after 29-- analysis and expansion of the main unit. 30 31-- b) Compilation of unit bodies that contain the bodies of inlined sub- 32-- programs. This is done only if inlining is enabled (-gnatn). Full inlining 33-- requires that a) and b) be mutually recursive, because each step may 34-- generate another generic expansion and further inlined calls. 35 36-- c) Front-end inlining for Inline_Always subprograms. This is primarily an 37-- expansion activity that is performed for performance reasons, and when the 38-- target does not use the GCC back end. 39 40-- d) Front-end inlining for GNATprove, to perform source transformations 41-- to simplify formal verification. The machinery used is the same as for 42-- Inline_Always subprograms, but there are fewer restrictions on the source 43-- of subprograms. 44 45with Alloc; 46with Opt; use Opt; 47with Sem; use Sem; 48with Table; 49with Types; use Types; 50with Warnsw; use Warnsw; 51 52package Inline is 53 54 -------------------------------- 55 -- Generic Body Instantiation -- 56 -------------------------------- 57 58 -- The bodies of generic instantiations are built after semantic analysis 59 -- of the main unit is complete. Generic instantiations are saved in a 60 -- global data structure, and the bodies constructed by means of a separate 61 -- analysis and expansion step. 62 63 -- See full description in body of Sem_Ch12 for more details 64 65 type Pending_Body_Info is record 66 Act_Decl : Node_Id; 67 -- Declaration for package or subprogram spec for instantiation 68 69 Config_Switches : Config_Switches_Type; 70 -- Capture the values of configuration switches 71 72 Current_Sem_Unit : Unit_Number_Type; 73 -- The semantic unit within which the instantiation is found. Must be 74 -- restored when compiling the body, to insure that internal entities 75 -- use the same counter and are unique over spec and body. 76 77 Expander_Status : Boolean; 78 -- If the body is instantiated only for semantic checking, expansion 79 -- must be inhibited. 80 81 Inst_Node : Node_Id; 82 -- Node for instantiation that requires the body 83 84 Scope_Suppress : Suppress_Record; 85 Local_Suppress_Stack_Top : Suppress_Stack_Entry_Ptr; 86 -- Save suppress information at the point of instantiation. Used to 87 -- properly inherit check status active at this point (see RM 11.5 88 -- (7.2/2), AI95-00224-01): 89 -- 90 -- "If a checking pragma applies to a generic instantiation, then the 91 -- checking pragma also applies to the instance. If a checking pragma 92 -- applies to a call to a subprogram that has a pragma Inline applied 93 -- to it, then the checking pragma also applies to the inlined 94 -- subprogram body". 95 -- 96 -- This means we have to capture this information from the current scope 97 -- at the point of instantiation. 98 99 Warnings : Warning_Record; 100 -- Capture values of warning flags 101 end record; 102 103 package Pending_Instantiations is new Table.Table ( 104 Table_Component_Type => Pending_Body_Info, 105 Table_Index_Type => Int, 106 Table_Low_Bound => 0, 107 Table_Initial => Alloc.Pending_Instantiations_Initial, 108 Table_Increment => Alloc.Pending_Instantiations_Increment, 109 Table_Name => "Pending_Instantiations"); 110 111 -- The following table records subprograms and packages for which 112 -- generation of subprogram descriptors must be delayed. 113 114 package Pending_Descriptor is new Table.Table ( 115 Table_Component_Type => Entity_Id, 116 Table_Index_Type => Int, 117 Table_Low_Bound => 0, 118 Table_Initial => Alloc.Pending_Instantiations_Initial, 119 Table_Increment => Alloc.Pending_Instantiations_Increment, 120 Table_Name => "Pending_Descriptor"); 121 122 -- The following should be initialized in an init call in Frontend, we 123 -- have thoughts of making the frontend reusable in future ??? 124 125 ----------------- 126 -- Subprograms -- 127 ----------------- 128 129 procedure Initialize; 130 -- Initialize internal tables 131 132 procedure Lock; 133 -- Lock internal tables before calling backend 134 135 procedure Instantiate_Bodies; 136 -- This procedure is called after semantic analysis is complete, to 137 -- instantiate the bodies of generic instantiations that appear in the 138 -- compilation unit. 139 140 procedure Add_Inlined_Body (E : Entity_Id; N : Node_Id); 141 -- E is an inlined subprogram appearing in a call, either explicitly or in 142 -- a discriminant check for which gigi builds a call or an at-end handler. 143 -- Add E's enclosing unit to Inlined_Bodies so that E can be subsequently 144 -- retrieved and analyzed. N is the node giving rise to the call to E. 145 146 procedure Analyze_Inlined_Bodies; 147 -- At end of compilation, analyze the bodies of all units that contain 148 -- inlined subprograms that are actually called. 149 150 procedure Build_Body_To_Inline (N : Node_Id; Spec_Id : Entity_Id); 151 -- If a subprogram has pragma Inline and inlining is active, use generic 152 -- machinery to build an unexpanded body for the subprogram. This body is 153 -- subsequently used for inline expansions at call sites. If subprogram can 154 -- be inlined (depending on size and nature of local declarations) the 155 -- template body is created. Otherwise subprogram body is treated normally 156 -- and calls are not inlined in the frontend. If proper warnings are 157 -- enabled and the subprogram contains a construct that cannot be inlined, 158 -- the problematic construct is flagged accordingly. 159 160 function Call_Can_Be_Inlined_In_GNATprove_Mode 161 (N : Node_Id; 162 Subp : Entity_Id) return Boolean; 163 -- Returns False if the call in node N to subprogram Subp cannot be inlined 164 -- in GNATprove mode, because it may lead to missing a check on type 165 -- conversion of input parameters otherwise. Returns True otherwise. 166 167 function Can_Be_Inlined_In_GNATprove_Mode 168 (Spec_Id : Entity_Id; 169 Body_Id : Entity_Id) return Boolean; 170 -- Returns True if the subprogram identified by Spec_Id and Body_Id can 171 -- be inlined in GNATprove mode. One but not both of Spec_Id and Body_Id 172 -- can be Empty. Body_Id is Empty when doing a partial check on a call 173 -- to a subprogram whose body has not been seen yet, to know whether this 174 -- subprogram could possibly be inlined. GNATprove relies on this to adapt 175 -- its treatment of the subprogram. 176 177 procedure Cannot_Inline 178 (Msg : String; 179 N : Node_Id; 180 Subp : Entity_Id; 181 Is_Serious : Boolean := False); 182 -- This procedure is called if the node N, an instance of a call to 183 -- subprogram Subp, cannot be inlined. Msg is the message to be issued, 184 -- which ends with ? (it does not end with ?p?, this routine takes care of 185 -- the need to change ? to ?p?). The behavior of this routine depends on 186 -- the value of Back_End_Inlining: 187 -- 188 -- * If Back_End_Inlining is not set (ie. legacy frontend inlining model) 189 -- then if Subp has a pragma Always_Inlined, then an error message is 190 -- issued (by removing the last character of Msg). If Subp is not 191 -- Always_Inlined, then a warning is issued if the flag Ineffective_ 192 -- Inline_Warnings is set, adding ?p to the msg, and if not, the call 193 -- has no effect. 194 -- 195 -- * If Back_End_Inlining is set then: 196 -- - If Is_Serious is true, then an error is reported (by removing the 197 -- last character of Msg); 198 -- 199 -- - otherwise: 200 -- 201 -- * Compiling without optimizations if Subp has a pragma 202 -- Always_Inlined, then an error message is issued; if Subp is 203 -- not Always_Inlined, then a warning is issued if the flag 204 -- Ineffective_Inline_Warnings is set (adding p?), and if not, 205 -- the call has no effect. 206 -- 207 -- * Compiling with optimizations then a warning is issued if the 208 -- flag Ineffective_Inline_Warnings is set (adding p?); otherwise 209 -- no effect since inlining may be performed by the backend. 210 211 procedure Check_And_Split_Unconstrained_Function 212 (N : Node_Id; 213 Spec_Id : Entity_Id; 214 Body_Id : Entity_Id); 215 -- Spec_Id and Body_Id are the entities of the specification and body of 216 -- the subprogram body N. If N can be inlined by the frontend (supported 217 -- cases documented in Check_Body_To_Inline) then build the body-to-inline 218 -- associated with N and attach it to the declaration node of Spec_Id. 219 220 procedure Check_Package_Body_For_Inlining (N : Node_Id; P : Entity_Id); 221 -- If front-end inlining is enabled and a package declaration contains 222 -- inlined subprograms, load and compile the package body to collect the 223 -- bodies of these subprograms, so they are available to inline calls. 224 -- N is the compilation unit for the package. 225 226 procedure Expand_Inlined_Call 227 (N : Node_Id; 228 Subp : Entity_Id; 229 Orig_Subp : Entity_Id); 230 -- If called subprogram can be inlined by the front-end, retrieve the 231 -- analyzed body, replace formals with actuals and expand call in place. 232 -- Generate thunks for actuals that are expressions, and insert the 233 -- corresponding constant declarations before the call. If the original 234 -- call is to a derived operation, the return type is the one of the 235 -- derived operation, but the body is that of the original, so return 236 -- expressions in the body must be converted to the desired type (which 237 -- is simply not noted in the tree without inline expansion). 238 239 function Has_Excluded_Declaration 240 (Subp : Entity_Id; 241 Decls : List_Id) return Boolean; 242 -- Check a list of declarations, Decls, that make the inlining of Subp not 243 -- worthwhile 244 245 function Has_Excluded_Statement 246 (Subp : Entity_Id; 247 Stats : List_Id) return Boolean; 248 -- Check a list of statements, Stats, that make inlining of Subp not 249 -- worthwhile, including any tasking statement, nested at any level. 250 251 procedure List_Inlining_Info; 252 -- Generate listing of calls inlined by the frontend plus listing of 253 -- calls to inline subprograms passed to the backend. 254 255 procedure Remove_Dead_Instance (N : Node_Id); 256 -- If an instantiation appears in unreachable code, delete the pending 257 -- body instance. 258 259end Inline; 260