1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                               I N L I N E                                --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2012, 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 two 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) an b) be mutually recursive, because each step may
34--  generate another generic expansion and further inlined calls. For now each
35--  of them uses a workpile algorithm, but they are called independently from
36--  Frontend, and thus are not mutually recursive.
37
38with Alloc;
39with Opt;   use Opt;
40with Sem;   use Sem;
41with Table;
42with Types; use Types;
43
44package Inline is
45
46   --------------------------------
47   -- Generic Body Instantiation --
48   --------------------------------
49
50   --  The bodies of generic instantiations are built after semantic analysis
51   --  of the main unit is complete. Generic instantiations are saved in a
52   --  global data structure, and the bodies constructed by means of a separate
53   --  analysis and expansion step.
54
55   --  See full description in body of Sem_Ch12 for more details
56
57   type Pending_Body_Info is record
58      Inst_Node : Node_Id;
59      --  Node for instantiation that requires the body
60
61      Act_Decl : Node_Id;
62      --  Declaration for package or subprogram spec for instantiation
63
64      Expander_Status : Boolean;
65      --  If the body is instantiated only for semantic checking, expansion
66      --  must be inhibited.
67
68      Current_Sem_Unit : Unit_Number_Type;
69      --  The semantic unit within which the instantiation is found. Must
70      --  be restored when compiling the body, to insure that internal enti-
71      --  ties use the same counter and are unique over spec and body.
72
73      Scope_Suppress           : Suppress_Record;
74      Local_Suppress_Stack_Top : Suppress_Stack_Entry_Ptr;
75      --  Save suppress information at the point of instantiation. Used to
76      --  properly inherit check status active at this point (see RM 11.5
77      --  (7.2/2), AI95-00224-01):
78      --
79      --    "If a checking pragma applies to a generic instantiation, then the
80      --    checking pragma also applies to the instance. If a checking pragma
81      --    applies to a call to a subprogram that has a pragma Inline applied
82      --    to it, then the checking pragma also applies to the inlined
83      --    subprogram body".
84      --
85      --  This means we have to capture this information from the current scope
86      --  at the point of instantiation.
87
88      Version : Ada_Version_Type;
89      --  The body must be compiled with the same language version as the
90      --  spec. The version may be set by a configuration pragma in a separate
91      --  file or in the current file, and may differ from body to body.
92   end record;
93
94   package Pending_Instantiations is new Table.Table (
95     Table_Component_Type => Pending_Body_Info,
96     Table_Index_Type     => Int,
97     Table_Low_Bound      => 0,
98     Table_Initial        => Alloc.Pending_Instantiations_Initial,
99     Table_Increment      => Alloc.Pending_Instantiations_Increment,
100     Table_Name           => "Pending_Instantiations");
101
102   --  The following table records subprograms and packages for which
103   --  generation of subprogram descriptors must be delayed.
104
105   package Pending_Descriptor is new Table.Table (
106     Table_Component_Type => Entity_Id,
107     Table_Index_Type     => Int,
108     Table_Low_Bound      => 0,
109     Table_Initial        => Alloc.Pending_Instantiations_Initial,
110     Table_Increment      => Alloc.Pending_Instantiations_Increment,
111     Table_Name           => "Pending_Descriptor");
112
113   -----------------
114   -- Subprograms --
115   -----------------
116
117   procedure Initialize;
118   --  Initialize internal tables
119
120   procedure Lock;
121   --  Lock internal tables before calling backend
122
123   procedure Instantiate_Bodies;
124   --  This procedure is called after semantic analysis is complete, to
125   --  instantiate the bodies of generic instantiations that appear in the
126   --  compilation unit.
127
128   procedure Add_Inlined_Body (E : Entity_Id);
129   --  E is an inlined subprogram appearing in a call, either explicitly, or
130   --  a discriminant check for which gigi builds a call.  Add E's enclosing
131   --  unit to Inlined_Bodies so that body of E can be subsequently retrieved
132   --  and analyzed.
133
134   procedure Analyze_Inlined_Bodies;
135   --  At end of compilation, analyze the bodies of all units that contain
136   --  inlined subprograms that are actually called.
137
138   procedure Check_Body_For_Inlining (N : Node_Id; P : Entity_Id);
139   --  If front-end inlining is enabled and a package declaration contains
140   --  inlined subprograms, load and compile the package body to collect the
141   --  bodies of these subprograms, so they are available to inline calls.
142   --  N is the compilation unit for the package.
143
144   procedure Remove_Dead_Instance (N : Node_Id);
145   --  If an instantiation appears in unreachable code, delete the pending
146   --  body instance.
147
148end Inline;
149