| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- G N A T P R E P -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2007, 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 program provides a simple preprocessing capability for Ada programs. |
| -- It is designed for use with GNAT, but is not dependent on any special |
| -- features of GNAT. |
| |
| -- To call gnatprep use |
| |
| -- gnatprep infile outfile [deffile] [-v] [-c] [-b] [-r] [-s] [-u] |
| -- [-Dsymbol=value] |
| |
| -- where |
| |
| -- infile is the full name of the input file, which is an Ada source |
| -- file containing preprocessor directives. |
| |
| -- outfile is the full name of the output file, which is an Ada source |
| -- in standard Ada form. When used with GNAT, this file name will |
| -- normally have an ads or adb suffix. |
| |
| -- deffile is the full name of a text file containing definitions of |
| -- symbols to be referenced by the preprocessor. This argument is |
| -- optional. |
| |
| -- The -c switch, causes both preprocessor lines and the lines deleted |
| -- by preprocessing to be retained in the output source as comments marked |
| -- with the special string "--! ". This option will result in line numbers |
| -- being preserved in the output file. |
| |
| -- The -b switch causes both preprocessor lines and the lines deleted by |
| -- preprocessing to be replaced by blank lines in the output source file, |
| -- thus preserving line numbers in the output file. |
| |
| -- The -r switch causes a Source_Reference pragma to be generated that |
| -- references the original input file, so that error messages will use |
| -- the file name of this original file. |
| |
| -- The -u switch causes gnatprep to treat any undefined symbol that it |
| -- encounters as having the value False. Otherwise an undefined symbol |
| -- is a fatal error. |
| |
| -- The -s switch causes a sorted list of symbol names and values to be |
| -- listed on the standard output file. |
| |
| -- The -v switch causes a Copyright notice to be displayed, and |
| -- lines containing errors in the input file or the definition file |
| -- to be displayed before the errors. |
| |
| -- The -D switch causes symbol 'symbol' to be associated with 'value'. |
| -- This symbols can then be referenced by the preprocessor. Several |
| -- -D switches may be specified. |
| |
| -- Note: if neither -b nor -c is present, then preprocessor lines and |
| -- deleted lines are completely removed from the output, unless -r is |
| -- specified, in which case -b is assumed. |
| |
| -- The definitions file contains lines of the form |
| |
| -- symbol := value |
| |
| -- where symbol is an identifier, following normal Ada (case-insensitive) |
| -- rules for its syntax, and value is one of the following: |
| |
| -- Empty, corresponding to a null substitution |
| |
| -- A string literal using normal Ada syntax |
| |
| -- Any sequence of characters from the set |
| -- (letters, digits, period, underline) |
| |
| -- Comment lines may also appear in the definitions file, starting with |
| -- the usual --, and comments may be added to the definitions lines. |
| |
| -- The input text may contain preprocessor conditional inclusion lines, |
| -- and also general symbol substitution sequences. |
| |
| -- The preprocessor conditional inclusion commands have the form |
| |
| -- #if <expression> [then] |
| -- lines |
| -- #elsif <expression> [then] |
| -- lines |
| -- #elsif <expression> [then] |
| -- lines |
| -- ... |
| -- #else |
| -- lines |
| -- #end if; |
| -- |
| -- Where expression is defined by the following grammar : |
| -- expression ::= <symbol> |
| -- expression ::= <symbol> = "<value>" |
| -- expression ::= <symbol> = <symbol> |
| -- expression ::= <symbol> 'Defined |
| -- expression ::= not <expression> |
| -- expression ::= <expression> and <expression> |
| -- expression ::= <expression> or <expression> |
| -- expression ::= <expression> and then <expression> |
| -- expression ::= <expression> or else <expression> |
| -- expression ::= ( <expression> ) |
| |
| -- "or" and "and" may not be used in the same expression without |
| -- using parentheses. |
| |
| -- For these Boolean tests, the symbol must have either the value True or |
| -- False. If the value is True, then the corresponding lines are included, |
| -- and if the value is False, they are excluded. It is an error to |
| -- reference a symbol not defined in the symbol definitions file, or |
| -- to reference a symbol that has a value other than True or False. |
| |
| -- The use of the not operator inverts the sense of this logical test, so |
| -- that the lines are included only if the symbol is not defined. |
| |
| -- The THEN keyword is optional as shown |
| |
| -- Spaces or tabs may appear between the # and the keyword. The keywords |
| -- and the symbols are case insensitive as in normal Ada code. Comments |
| -- may be used on a preprocessor line, but other than that, no other |
| -- tokens may appear on a preprocessor line. |
| |
| -- Any number of #elsif clauses can be present, including none at all |
| |
| -- The #else is optional, as in Ada |
| |
| -- The # marking the start of a preprocessor line must be the first |
| -- non-blank character on the line, i.e. it must be preceded only by |
| -- spaces or horizontal tabs. |
| |
| -- Symbol substitution is obtained by using the sequence |
| |
| -- $symbol |
| |
| -- anywhere within a source line, except in a comment. The identifier |
| -- following the $ must match one of the symbols defined in the symbol |
| -- definition file, and the result is to substitute the value of the |
| -- symbol in place of $symbol in the output file. |
| |
| procedure GNATprep; |
