gcc/ada/errutil.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              E R R U T I L                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2002 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 2,  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 COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 --  This package contains routines to output error messages and the
  28 --  corresponding instantiation of Styleg, suitable to instantiate Scng.
  29
  30 --  It is not dependent on the GNAT tree packages (Atree, Sinfo, ...).
  31
  32 --  It uses the same global variables as Errout, located in package
  33 --  Err_Vars. Like Errout, it also uses the common variables and routines
  34 --  in package Erroutc.
  35
  36 --  This package is used by the preprocessor (gprep.adb) and the project
  37 --  manager (prj-err.ads).
  38
  39 with Styleg;
  40 with Types; use Types;
  41
  42 package Errutil is
  43
  44    ---------------------------------------------------------
  45    -- Error Message Text and Message Insertion Characters --
  46    ---------------------------------------------------------
  47
  48    --  Error message text strings are composed of lower case letters, digits
  49    --  and the special characters space, comma, period, colon and semicolon,
  50    --  apostrophe and parentheses. Special insertion characters can also
  51    --  appear which cause the error message circuit to modify the given
  52    --  string as follows:
  53
  54    --    Ignored insertion characters: the following characters, used as
  55    --      insertion characters by Errout are ignored: '$', '&', and '}'.
  56    --      If present in an error message, they are not output and are not
  57    --      replaced by any text.
  58
  59    --    Insertion character % (Percent: insert name from Names table)
  60    --      The character % is replaced by the text for the name specified by
  61    --      the Name_Id value stored in Error_Msg_Name_1. A blank precedes
  62    --      the name if it is preceded by a non-blank character other than a
  63    --      left parenthesis. The name is enclosed in quotes unless manual
  64    --      quotation mode is set. If the Name_Id is set to No_Name, then
  65    --      no insertion occurs; if the Name_Id is set to Error_Name, then
  66    --      the string <error> is inserted. A second and third % may appear
  67    --      in a single message, similarly replaced by the names which are
  68    --      specified by the Name_Id values stored in Error_Msg_Name_2 and
  69    --      Error_Msg_Name_3. The names are decoded and cased according to
  70    --      the current identifier casing mode.
  71
  72    --    Insertion character { (Left brace: insert literally from names table)
  73    --      The character { is treated similarly to %, except that the
  74    --      name is output literally as stored in the names table without
  75    --      adjusting the casing. This can be used for file names and in
  76    --      other situations where the name string is to be output unchanged.
  77
  78    --    Insertion character * (Asterisk, insert reserved word name)
  79    --      The insertion character * is treated exactly like % except that
  80    --      the resulting name is cased according to the default conventions
  81    --      for reserved words (see package Scans).
  82
  83    --    Insertion character # (Pound: insert line number reference)
  84    --      The character # is replaced by the string indicating the source
  85    --      position stored in Error_Msg_Sloc. There are two cases:
  86    --
  87    --        for locations in current file:  at line nnn:ccc
  88    --        for locations in other files:   at filename:nnn:ccc
  89    --
  90    --      By convention, the # insertion character is only used at the end
  91    --      of an error message, so the above strings only appear as the last
  92    --      characters of an error message.
  93
  94    --    Insertion character @ (At: insert column number reference)
  95    --      The character @ is replaced by null if the RM_Column_Check mode is
  96    --      off (False). If the switch is on (True), then @ is replaced by the
  97    --      text string " in column nnn" where nnn is the decimal representation
  98    --      of the column number stored in Error_Msg_Col plus one (the plus one
  99    --      is because the number is stored 0-origin and displayed 1-origin).
 100
 101    --    Insertion character ^ (Carret: insert integer value)
 102    --      The character ^ is replaced by the decimal conversion of the Uint
 103    --      value stored in Error_Msg_Uint_1, with a possible leading minus.
 104    --      A second ^ may occur in the message, in which case it is replaced
 105    --      by the decimal conversion of the Uint value in Error_Msg_Uint_2.
 106
 107    --    Insertion character ! (Exclamation: unconditional message)
 108    --      The character ! appearing as the last character of a message makes
 109    --      the message unconditional which means that it is output even if it
 110    --      would normally be suppressed.
 111
 112    --    Insertion character ? (Question: warning message)
 113    --      The character ? appearing anywhere in a message makes the message
 114    --      a warning instead of a normal error message, and the text of the
 115    --      message will be preceded by "Warning:" instead of "Error:" The
 116    --      handling of warnings if further controlled by the Warning_Mode
 117    --      option (-w switch), see package Opt for further details, and
 118    --      also by the current setting from pragma Warnings. This pragma
 119    --      applies only to warnings issued from the semantic phase (not
 120    --      the parser), but currently all relevant warnings are posted
 121    --      by the semantic phase anyway. Messages starting with (style)
 122    --      are also treated as warning messages.
 123
 124    --    Insertion character A-Z (Upper case letter: Ada reserved word)
 125    --      If two or more upper case letters appear in the message, they are
 126    --      taken as an Ada reserved word, and are converted to the default
 127    --      case for reserved words (see Scans package spec). Surrounding
 128    --      quotes are added unless manual quotation mode is currently set.
 129
 130    --    Insertion character ` (Backquote: set manual quotation mode)
 131    --      The backquote character always appears in pairs. Each backquote
 132    --      of the pair is replaced by a double quote character. In addition,
 133    --      Any reserved keywords, or name insertions between these backquotes
 134    --      are not surrounded by the usual automatic double quotes. See the
 135    --      section below on manual quotation mode for further details.
 136
 137    --    Insertion character ' (Quote: literal character)
 138    --      Precedes a character which is placed literally into the message.
 139    --      Used to insert characters into messages that are one of the
 140    --      insertion characters defined here.
 141
 142    --    Insertion character \ (Backslash: continuation message)
 143    --      Indicates that the message is a continuation of a message
 144    --      previously posted. This is used to ensure that such groups
 145    --      of messages are treated as a unit. The \ character must be
 146    --      the first character of the message text.
 147
 148    -----------------------------------------------------
 149    -- Format of Messages and Manual Quotation Control --
 150    -----------------------------------------------------
 151
 152    --  Messages are generally all in lower case, except for inserted names
 153    --  and appear in one of the following two forms:
 154
 155    --    error: text
 156    --    warning: text
 157
 158    --  The prefixes error and warning are supplied automatically (depending
 159    --  on the use of the ? insertion character), and the call to the error
 160    --  message routine supplies the text. The "error: " prefix is omitted
 161    --  in brief error message formats.
 162
 163    --  Reserved keywords in the message are in the default keyword case
 164    --  (determined from the given source program), surrounded by quotation
 165    --  marks. This is achieved by spelling the reserved word in upper case
 166    --  letters, which is recognized as a request for insertion of quotation
 167    --  marks by the error text processor. Thus for example:
 168
 169    --    Error_Msg_AP ("IS expected");
 170
 171    --  would result in the output of one of the following:
 172
 173    --    error: "is" expected
 174    --    error: "IS" expected
 175    --    error: "Is" expected
 176
 177    --  the choice between these being made by looking at the casing convention
 178    --  used for keywords (actually the first compilation unit keyword) in the
 179    --  source file.
 180
 181    --  In the case of names, the default mode for the error text processor
 182    --  is to surround the name by quotation marks automatically. The case
 183    --  used for the identifier names is taken from the source program where
 184    --  possible, and otherwise is the default casing convention taken from
 185    --  the source file usage.
 186
 187    --  In some cases, better control over the placement of quote marks is
 188    --  required. This is achieved using manual quotation mode. In this mode,
 189    --  one or more insertion sequences is surrounded by backquote characters.
 190    --  The backquote characters are output as double quote marks, and normal
 191    --  automatic insertion of quotes is suppressed between the double quotes.
 192    --  For example:
 193
 194    --    Error_Msg_AP ("`END &;` expected");
 195
 196    --  generates a message like
 197
 198    --    error: "end Open_Scope;" expected
 199
 200    --  where the node specifying the name Open_Scope has been stored in
 201    --  Error_Msg_Node_1 prior to the call. The great majority of error
 202    --  messages operates in normal quotation mode.
 203
 204    --  Note: the normal automatic insertion of spaces before insertion
 205    --  sequences (such as those that come from & and %) is suppressed in
 206    --  manual quotation mode, so blanks, if needed as in the above example,
 207    --  must be explicitly present.
 208
 209    ------------------------------
 210    -- Error Output Subprograms --
 211    ------------------------------
 212
 213    procedure Initialize;
 214    --  Initializes for output of error messages. Must be called for each
 215    --  file before using any of the other routines in the package.
 216
 217    procedure Finalize (Source_Type : String := "project");
 218    --  Finalize processing of error messages for one file and output message
 219    --  indicating the number of detected errors.
 220    --  Source_Type is used in verbose mode to indicate the type of the source
 221    --  being parsed (project file, definition file or input file for the
 222    --  preprocessor).
 223
 224    procedure Error_Msg (Msg : String; Flag_Location : Source_Ptr);
 225    --  Output a message at specified location.
 226
 227    procedure Error_Msg_S (Msg : String);
 228    --  Output a message at current scan pointer location.
 229
 230    procedure Error_Msg_SC (Msg : String);
 231    --  Output a message at the start of the current token, unless we are at
 232    --  the end of file, in which case we always output the message after the
 233    --  last real token in the file.
 234
 235    procedure Error_Msg_SP (Msg : String);
 236    --  Output a message at the start of the previous token.
 237
 238    procedure Set_Ignore_Errors (To : Boolean);
 239    --  Indicate, when To = True, that all reported errors should
 240    --  be ignored. By default reported errors are not ignored.
 241
 242    package Style is new Styleg
 243      (Error_Msg    => Error_Msg,
 244       Error_Msg_S  => Error_Msg_S,
 245       Error_Msg_SC => Error_Msg_SC,
 246       Error_Msg_SP => Error_Msg_SP);
 247    --  Instantiation of the generic style package, suitable for an
 248    --  instantiation of Scng.
 249
 250 end Errutil;