| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- I N L I N E -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2022, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
| -- http://www.gnu.org/licenses for a complete copy of the license. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This module handles four kinds of inlining activity: |
| |
| -- a) Instantiation of generic bodies. This is done unconditionally, after |
| -- analysis and expansion of the main unit. |
| |
| -- b) Compilation of unit bodies that contain the bodies of inlined sub- |
| -- programs. This is done only if inlining is enabled (-gnatn). Full inlining |
| -- requires that a) and b) be mutually recursive, because each step may |
| -- generate another generic expansion and further inlined calls. |
| |
| -- c) Front-end inlining for Inline_Always subprograms. This is primarily an |
| -- expansion activity that is performed for performance reasons, and when the |
| -- target does not use the GCC back end. |
| |
| -- d) Front-end inlining for GNATprove, to perform source transformations |
| -- to simplify formal verification. The machinery used is the same as for |
| -- Inline_Always subprograms, but there are fewer restrictions on the source |
| -- of subprograms. |
| |
| with Opt; use Opt; |
| with Sem; use Sem; |
| with Types; use Types; |
| with Warnsw; use Warnsw; |
| |
| package Inline is |
| |
| -------------------------------- |
| -- Generic Body Instantiation -- |
| -------------------------------- |
| |
| -- The bodies of generic instantiations are built after semantic analysis |
| -- of the main unit is complete. Generic instantiations are saved in a |
| -- global data structure, and the bodies constructed by means of a separate |
| -- analysis and expansion step. |
| |
| -- See full description in body of Sem_Ch12 for more details |
| |
| type Pending_Body_Info is record |
| Act_Decl : Node_Id; |
| -- Declaration for package or subprogram spec for instantiation |
| |
| Config_Switches : Config_Switches_Type; |
| -- Capture the values of configuration switches |
| |
| Current_Sem_Unit : Unit_Number_Type; |
| -- The semantic unit within which the instantiation is found. Must be |
| -- restored when compiling the body, to insure that internal entities |
| -- use the same counter and are unique over spec and body. |
| |
| Expander_Status : Boolean; |
| -- If the body is instantiated only for semantic checking, expansion |
| -- must be inhibited. |
| |
| Inst_Node : Node_Id; |
| -- Node for instantiation that requires the body |
| |
| Scope_Suppress : Suppress_Record; |
| Local_Suppress_Stack_Top : Suppress_Stack_Entry_Ptr; |
| -- Save suppress information at the point of instantiation. Used to |
| -- properly inherit check status active at this point (see RM 11.5 |
| -- (7.2/2), AI95-00224-01): |
| -- |
| -- "If a checking pragma applies to a generic instantiation, then the |
| -- checking pragma also applies to the instance. If a checking pragma |
| -- applies to a call to a subprogram that has a pragma Inline applied |
| -- to it, then the checking pragma also applies to the inlined |
| -- subprogram body". |
| -- |
| -- This means we have to capture this information from the current scope |
| -- at the point of instantiation. |
| |
| Warnings : Warnings_State; |
| -- Capture values of warning flags |
| end record; |
| |
| ----------------- |
| -- Subprograms -- |
| ----------------- |
| |
| procedure Initialize; |
| -- Initialize internal tables |
| |
| procedure Lock; |
| -- Lock internal tables before calling backend |
| |
| procedure Instantiate_Bodies; |
| -- This procedure is called after semantic analysis is complete, to |
| -- instantiate the bodies of generic instantiations that appear in the |
| -- compilation unit. |
| |
| procedure Add_Inlined_Body (E : Entity_Id; N : Node_Id); |
| -- E is an inlined subprogram appearing in a call, either explicitly or in |
| -- a discriminant check for which gigi builds a call or an at-end handler. |
| -- Add E's enclosing unit to Inlined_Bodies so that E can be subsequently |
| -- retrieved and analyzed. N is the node giving rise to the call to E. |
| |
| procedure Add_Pending_Instantiation (Inst : Node_Id; Act_Decl : Node_Id); |
| -- Add an entry in the table of generic bodies to be instantiated. |
| |
| procedure Analyze_Inlined_Bodies; |
| -- At end of compilation, analyze the bodies of all units that contain |
| -- inlined subprograms that are actually called. |
| |
| procedure Build_Body_To_Inline (N : Node_Id; Spec_Id : Entity_Id); |
| -- If a subprogram has pragma Inline and inlining is active, use generic |
| -- machinery to build an unexpanded body for the subprogram. This body is |
| -- subsequently used for inline expansions at call sites. If subprogram can |
| -- be inlined (depending on size and nature of local declarations) the |
| -- template body is created. Otherwise subprogram body is treated normally |
| -- and calls are not inlined in the frontend. If proper warnings are |
| -- enabled and the subprogram contains a construct that cannot be inlined, |
| -- the problematic construct is flagged accordingly. |
| |
| function Call_Can_Be_Inlined_In_GNATprove_Mode |
| (N : Node_Id; |
| Subp : Entity_Id) return Boolean; |
| -- Returns False if the call in node N to subprogram Subp cannot be inlined |
| -- in GNATprove mode, because it may lead to missing a check on type |
| -- conversion of input parameters otherwise. Returns True otherwise. |
| |
| function Can_Be_Inlined_In_GNATprove_Mode |
| (Spec_Id : Entity_Id; |
| Body_Id : Entity_Id) return Boolean; |
| -- Returns True if the subprogram identified by Spec_Id and Body_Id can |
| -- be inlined in GNATprove mode. One but not both of Spec_Id and Body_Id |
| -- can be Empty. Body_Id is Empty when doing a partial check on a call |
| -- to a subprogram whose body has not been seen yet, to know whether this |
| -- subprogram could possibly be inlined. GNATprove relies on this to adapt |
| -- its treatment of the subprogram. |
| |
| procedure Cannot_Inline |
| (Msg : String; |
| N : Node_Id; |
| Subp : Entity_Id; |
| Is_Serious : Boolean := False; |
| Suppress_Info : Boolean := False); |
| -- This procedure is called if the node N, an instance of a call to |
| -- subprogram Subp, cannot be inlined. Msg is the message to be issued, |
| -- which ends with ? (it does not end with ?p?, this routine takes care of |
| -- the need to change ? to ?p?). Suppress_Info is set to True to prevent |
| -- issuing an info message in GNATprove mode. The behavior of this routine |
| -- depends on the value of Back_End_Inlining: |
| -- |
| -- * If Back_End_Inlining is not set (ie. legacy frontend inlining model) |
| -- then if Subp has a pragma Always_Inlined, then an error message is |
| -- issued (by removing the last character of Msg). If Subp is not |
| -- Always_Inlined, then a warning is issued if the flag Ineffective_ |
| -- Inline_Warnings is set, adding ?p to the msg, and if not, the call |
| -- has no effect. |
| -- |
| -- * If Back_End_Inlining is set then: |
| -- - If Is_Serious is true, then an error is reported (by removing the |
| -- last character of Msg); |
| -- |
| -- - otherwise: |
| -- |
| -- * Compiling without optimizations if Subp has a pragma |
| -- Always_Inlined, then an error message is issued; if Subp is |
| -- not Always_Inlined, then a warning is issued if the flag |
| -- Ineffective_Inline_Warnings is set (adding p?), and if not, |
| -- the call has no effect. |
| -- |
| -- * Compiling with optimizations then a warning is issued if the |
| -- flag Ineffective_Inline_Warnings is set (adding p?); otherwise |
| -- no effect since inlining may be performed by the backend. |
| |
| procedure Check_And_Split_Unconstrained_Function |
| (N : Node_Id; |
| Spec_Id : Entity_Id; |
| Body_Id : Entity_Id); |
| -- Spec_Id and Body_Id are the entities of the specification and body of |
| -- the subprogram body N. If N can be inlined by the frontend (supported |
| -- cases documented in Check_Body_To_Inline) then build the body-to-inline |
| -- associated with N and attach it to the declaration node of Spec_Id. |
| |
| procedure Check_Object_Renaming_In_GNATprove_Mode (Spec_Id : Entity_Id) |
| with |
| Pre => GNATprove_Mode; |
| -- This procedure is called only in GNATprove mode, on subprograms for |
| -- which a Body_To_Inline was created, to check if the subprogram has |
| -- references to object renamings which will be replaced by the special |
| -- SPARK expansion into nodes of a different kind, which is not expected |
| -- by the inlining mechanism. In that case, the Body_To_Inline is deleted. |
| |
| procedure Check_Package_Body_For_Inlining (N : Node_Id; P : Entity_Id); |
| -- If front-end inlining is enabled and a package declaration contains |
| -- inlined subprograms, load and compile the package body to collect the |
| -- bodies of these subprograms, so they are available to inline calls. |
| -- N is the compilation unit for the package. |
| |
| procedure Expand_Inlined_Call |
| (N : Node_Id; |
| Subp : Entity_Id; |
| Orig_Subp : Entity_Id); |
| -- If called subprogram can be inlined by the front-end, retrieve the |
| -- analyzed body, replace formals with actuals and expand call in place. |
| -- Generate thunks for actuals that are expressions, and insert the |
| -- corresponding constant declarations before the call. If the original |
| -- call is to a derived operation, the return type is the one of the |
| -- derived operation, but the body is that of the original, so return |
| -- expressions in the body must be converted to the desired type (which |
| -- is simply not noted in the tree without inline expansion). |
| |
| function Has_Excluded_Declaration |
| (Subp : Entity_Id; |
| Decls : List_Id) return Boolean; |
| -- Check a list of declarations, Decls, that make the inlining of Subp not |
| -- worthwhile |
| |
| function Has_Excluded_Statement |
| (Subp : Entity_Id; |
| Stats : List_Id) return Boolean; |
| -- Check a list of statements, Stats, that make inlining of Subp not |
| -- worthwhile, including any tasking statement, nested at any level. |
| |
| procedure Inline_Static_Function_Call |
| (N : Node_Id; Subp : Entity_Id); |
| -- Evaluate static call to a static function Subp, substituting actuals in |
| -- place of references to their corresponding formals and rewriting the |
| -- call N as a fully folded and static result expression. |
| |
| procedure List_Inlining_Info; |
| -- Generate listing of calls inlined by the frontend plus listing of |
| -- calls to inline subprograms passed to the backend. |
| |
| procedure Remove_Dead_Instance (N : Node_Id); |
| -- If an instantiation appears in unreachable code, delete the pending |
| -- body instance. |
| |
| end Inline; |
