1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                               S W I T C H                                --
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 package together with a child package appropriate to the client tool
27--  scans switches. Note that the body of the appropriate Usage package must be
28--  coordinated with the switches that are recognized by this package. These
29--  Usage packages also act as the official documentation for the switches
30--  that are recognized. In addition, package Debug documents the otherwise
31--  undocumented debug switches that are also recognized.
32
33with Gnatvsn;
34with Types; use Types;
35
36------------
37-- Switch --
38------------
39
40package Switch is
41
42   --  Common switches for GNU tools
43
44   Version_Switch : constant String := "--version";
45   Help_Switch    : constant String := "--help";
46
47   -----------------
48   -- Subprograms --
49   -----------------
50
51   generic
52      with procedure Usage;
53      --  Print tool-specific part of --help message
54   procedure Check_Version_And_Help_G
55     (Tool_Name      : String;
56      Initial_Year   : String;
57      Version_String : String := Gnatvsn.Gnat_Version_String);
58   --  Check if switches --version or --help is used. If one of this switch is
59   --  used, issue the proper messages and end the process.
60
61   procedure Display_Version
62     (Tool_Name      : String;
63      Initial_Year   : String;
64      Version_String : String := Gnatvsn.Gnat_Version_String);
65   --  Display version of a tool when switch --version is used
66
67   procedure Display_Usage_Version_And_Help;
68   --  Output the two lines of usage for switches --version and --help
69
70   function Is_Switch (Switch_Chars : String) return Boolean;
71   --  Returns True iff Switch_Chars is at least two characters long, and the
72   --  first character is an hyphen ('-').
73
74   function Is_Front_End_Switch (Switch_Chars : String) return Boolean;
75   --  Returns True iff Switch_Chars represents a front-end switch, i.e. it
76   --  starts with -I, -gnat or -?RTS.
77
78   function Is_Internal_GCC_Switch (Switch_Chars : String) return Boolean;
79   --  Returns True iff Switch_Chars represents an internal GCC switch to be
80   --  followed by a single argument, such as -dumpbase, --param or -auxbase.
81   --  Even though passed by the "gcc" driver, these need not be stored in ALI
82   --  files and may safely be ignored by non GCC back-ends.
83
84   function Switch_Last (Switch_Chars : String) return Natural;
85   --  Index in Switch_Chars of the last relevant character for later string
86   --  comparison purposes. This is typically 'Last, minus one if there is a
87   --  terminating ASCII.NUL.
88
89private
90   --  This section contains some common routines used by the tool dependent
91   --  child packages (there is one such child package for each tool that uses
92   --  Switches to scan switches - Compiler/gnatbind/gnatmake/.
93
94   Switch_Max_Value : constant := 999_999;
95   --  Maximum value permitted in switches that take a value
96
97   function Nat_Present
98     (Switch_Chars : String;
99      Max          : Integer;
100      Ptr          : Integer) return Boolean;
101   --  Returns True if an integer is at the current scan location or an equal
102   --  sign. This is used as a guard for calling Scan_Nat. Switch_Chars is the
103   --  string containing the switch, and Ptr points just past the switch
104   --  character. Max is the maximum allowed value of Ptr.
105
106   procedure Scan_Nat
107     (Switch_Chars : String;
108      Max          : Integer;
109      Ptr          : in out Integer;
110      Result       : out Nat;
111      Switch       : Character);
112   --  Scan natural integer parameter for switch. On entry, Ptr points just
113   --  past the switch character, on exit it points past the last digit of the
114   --  integer value. Max is the maximum allowed value of Ptr, so the scan is
115   --  restricted to Switch_Chars (Ptr .. Max). It is possible for Ptr to be
116   --  one greater than Max on return if the entire string is digits. Scan_Nat
117   --  will skip an optional equal sign if it is present. Nat_Present must be
118   --  True, or an error will be signalled.
119
120   procedure Scan_Pos
121     (Switch_Chars : String;
122      Max          : Integer;
123      Ptr          : in out Integer;
124      Result       : out Pos;
125      Switch       : Character);
126   --  Scan positive integer parameter for switch. Identical to Scan_Nat with
127   --  same parameters except that zero is considered out of range.
128
129   procedure Bad_Switch (Switch : Character);
130   procedure Bad_Switch (Switch : String);
131   pragma No_Return (Bad_Switch);
132   --  Fail with an appropriate message when a switch is not recognized
133
134end Switch;
135