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-- --
-- --
-- E R R O U T --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2003 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
-- This package contains the routines to output error messages. They
-- are basically system independent, however in some environments, e.g.
-- when the parser is embedded into an editor, it may be appropriate
-- to replace the implementation of this package.
with Err_Vars;
with Erroutc;
with Table;
with Types; use Types;
with Uintp; use Uintp;
with System;
package Errout is
Serious_Errors_Detected : Nat renames Err_Vars.Serious_Errors_Detected;
-- This is a count of errors that are serious enough to stop expansion,
-- and hence to prevent generation of an object file even if the
-- switch -gnatQ is set.
Total_Errors_Detected : Nat renames Err_Vars.Total_Errors_Detected;
-- Number of errors detected so far. Includes count of serious errors
-- and non-serious errors, so this value is always greater than or
-- equal to the Serious_Errors_Detected value.
Warnings_Detected : Nat renames Err_Vars.Warnings_Detected;
-- Number of warnings detected
Configurable_Run_Time_Violations : Nat := 0;
-- Count of configurable run time violations so far. This is used to
-- suppress certain cascaded error messages when we know that we may not
-- have fully expanded some items, due to high integrity violations (i.e.
-- the use of constructs not permitted by the library in use, or
-- improper constructs in No_Run_Time mode).
type Compiler_State_Type is (Parsing, Analyzing);
Compiler_State : Compiler_State_Type;
-- Indicates current state of compilation. This is put in the Errout
-- spec because it affects the action of the error message handling.
-- In particular, an attempt is made by Errout to suppress cascaded
-- error messages in Parsing mode, but not in the other modes.
Current_Error_Source_File : Source_File_Index
renames Err_Vars.Current_Error_Source_File;
-- Id of current messages. Used to post file name when unit changes. This
-- is initialized to Main_Source_File at the start of a compilation, which
-- means that no file names will be output unless there are errors in units
-- other than the main unit. However, if the main unit has a pragma
-- Source_Reference line, then this is initialized to No_Source_File,
-- to force an initial reference to the real source file name.
Raise_Exception_On_Error : Nat renames Err_Vars.Raise_Exception_On_Error;
-- If this value is non-zero, then any attempt to generate an error
-- message raises the exception Error_Msg_Exception, and the error
-- message is not output. This is used for defending against junk
-- resulting from illegalities, and also for substitution of more
-- appropriate error messages from higher semantic levels. It is
-- a counter so that the increment/decrement protocol nests neatly.
Error_Msg_Exception : exception renames Err_Vars.Error_Msg_Exception;
-- Exception raised if Raise_Exception_On_Error is true
-- Suppression of Error Messages --
-- In an effort to reduce the impact of redundant error messages, the
-- error output routines in this package normally suppress certain
-- classes of messages as follows:
-- 1. Identical messages placed at the same point in the text. Such
-- duplicate error message result for example from rescanning
-- sections of the text that contain lexical errors. Only one of
-- such a set of duplicate messages is output, and the rest are
-- suppressed.
-- 2. If more than one parser message is generated for a single source
-- line, then only the first message is output, the remaining
-- messages on the same line are suppressed.
-- 3. If a message is posted on a node for which a message has been
-- previously posted, then only the first message is retained. The
-- Error_Posted flag is used to detect such multiple postings. Note
-- that this only applies to semantic messages, since otherwise
-- for parser messages, this would be a special case of case 2.
-- 4. If a message is posted on a node whose Etype or Entity
-- fields reference entities on which an error message has
-- already been placed, as indicated by the Error_Posted flag
-- being set on these entities, then the message is suppressed.
-- 5. If a message attempts to insert an Error node, or a direct
-- reference to the Any_Type node, then the message is suppressed.
-- This normal suppression action may be overridden in cases 2-5 (but not
-- in case 1) by setting All_Errors mode, or by setting the special
-- unconditional message insertion character (!) at the end of the message
-- text as described below.
-- Error Message Text and Message Insertion Characters --
-- Error message text strings are composed of lower case letters, digits
-- and the special characters space, comma, period, colon and semicolon,
-- apostrophe and parentheses. Special insertion characters can also
-- appear which cause the error message circuit to modify the given
-- string as follows:
-- Insertion character % (Percent: insert name from Names table)
-- The character % is replaced by the text for the name specified by
-- the Name_Id value stored in Error_Msg_Name_1. A blank precedes
-- the name if it is preceded by a non-blank character other than a
-- left parenthesis. The name is enclosed in quotes unless manual
-- quotation mode is set. If the Name_Id is set to No_Name, then
-- no insertion occurs; if the Name_Id is set to Error_Name, then
-- the string <error> is inserted. A second and third % may appear
-- in a single message, similarly replaced by the names which are
-- specified by the Name_Id values stored in Error_Msg_Name_2 and
-- Error_Msg_Name_3. The names are decoded and cased according to
-- the current identifier casing mode.
-- Insertion character $ (Dollar: insert unit name from Names table)
-- The character $ is treated similarly to %, except that the name
-- is obtained from the Unit_Name_Type value in Error_Msg_Unit_1
-- and Error_Msg_Unit_2, as provided by Get_Unit_Name_String in
-- package Uname. Note that this name includes the postfix (spec)
-- or (body) strings. If this postfix is not required, use the
-- normal % insertion for the unit name.
-- Insertion character { (Left brace: insert literally from names table)
-- The character { is treated similarly to %, except that the
-- name is output literally as stored in the names table without
-- adjusting the casing. This can be used for file names and in
-- other situations where the name string is to be output unchanged.
-- Insertion character * (Asterisk, insert reserved word name)
-- The insertion character * is treated exactly like % except that
-- the resulting name is cased according to the default conventions
-- for reserved words (see package Scans).
-- Insertion character & (Ampersand: insert name from node)
-- The insertion character & is treated similarly to %, except that
-- the name is taken from the Chars field of the given node, and may
-- refer to a child unit name, or a selected component. The casing
-- is, if possible, taken from the original source reference, which
-- is obtained from the Sloc field of the given node or nodes. If no
-- Sloc is available (happens e.g. for nodes in package Standard),
-- then the default case (see Scans spec) is used. The nodes to be
-- used are stored in Error_Msg_Node_1, Error_Msg_Node_2. No insertion
-- occurs for the Empty node, and the Error node results in the
-- insertion of the characters <error>. In addition, if the special
-- global variable Error_Msg_Qual_Level is non-zero, then the
-- reference will include up to the given number of levels of
-- qualification, using the scope chain.
-- Insertion character # (Pound: insert line number reference)
-- The character # is replaced by the string indicating the source
-- position stored in Error_Msg_Sloc. There are three cases:
-- for package Standard: in package Standard
-- for locations in current file: at line nnn:ccc
-- for locations in other files: at filename:nnn:ccc
-- By convention, the # insertion character is only used at the end
-- of an error message, so the above strings only appear as the last
-- characters of an error message.
-- Insertion character } (Right brace: insert type reference)
-- The character } is replaced by a string describing the type
-- referenced by the entity whose Id is stored in Error_Msg_Node_1.
-- the string gives the name or description of the type, and also
-- where appropriate the location of its declaration. Special
-- cases like "some integer type" are handled appropriately. Only
-- one } is allowed in a message, since there is not enough room
-- for two (the insertion can be quite long, including a file name)
-- In addition, if the special global variable Error_Msg_Qual_Level
-- is non-zero, then the reference will include up to the given
-- number of levels of qualification, using the scope chain.
-- Insertion character @ (At: insert column number reference)
-- The character @ is replaced by null if the RM_Column_Check mode is
-- off (False). If the switch is on (True), then @ is replaced by the
-- text string " in column nnn" where nnn is the decimal representation
-- of the column number stored in Error_Msg_Col plus one (the plus one
-- is because the number is stored 0-origin and displayed 1-origin).
-- Insertion character ^ (Carret: insert integer value)
-- The character ^ is replaced by the decimal conversion of the Uint
-- value stored in Error_Msg_Uint_1, with a possible leading minus.
-- A second ^ may occur in the message, in which case it is replaced
-- by the decimal conversion of the Uint value in Error_Msg_Uint_2.
-- Insertion character > (Right bracket, run time name)
-- The character > is replaced by a string of the form (name) if
-- Targparm scanned out a Run_Time_Name (see package Targparm for
-- details). The name is enclosed in parentheses and output in mixed
-- case mode (upper case after any space in the name). If no run time
-- name is defined, this insertion character has no effect.
-- Insertion character ! (Exclamation: unconditional message)
-- The character ! appearing as the last character of a message makes
-- the message unconditional which means that it is output even if it
-- would normally be suppressed. See section above for a description
-- of the cases in which messages are normally suppressed.
-- Insertion character ? (Question: warning message)
-- The character ? appearing anywhere in a message makes the message
-- a warning instead of a normal error message, and the text of the
-- message will be preceded by "Warning:" instead of "Error:" The
-- handling of warnings if further controlled by the Warning_Mode
-- option (-w switch), see package Opt for further details, and
-- also by the current setting from pragma Warnings. This pragma
-- applies only to warnings issued from the semantic phase (not
-- the parser), but currently all relevant warnings are posted
-- by the semantic phase anyway. Messages starting with (style)
-- are also treated as warning messages.
-- Insertion character A-Z (Upper case letter: Ada reserved word)
-- If two or more upper case letters appear in the message, they are
-- taken as an Ada reserved word, and are converted to the default
-- case for reserved words (see Scans package spec). Surrounding
-- quotes are added unless manual quotation mode is currently set.
-- Insertion character ` (Backquote: set manual quotation mode)
-- The backquote character always appears in pairs. Each backquote
-- of the pair is replaced by a double quote character. In addition,
-- Any reserved keywords, or name insertions between these backquotes
-- are not surrounded by the usual automatic double quotes. See the
-- section below on manual quotation mode for further details.
-- Insertion character ' (Quote: literal character)
-- Precedes a character which is placed literally into the message.
-- Used to insert characters into messages that are one of the
-- insertion characters defined here. Also useful in inserting
-- sequences of upper case letters (e.g. RM) which are not to be
-- treated as keywords.
-- Insertion character \ (Backslash: continuation message)
-- Indicates that the message is a continuation of a message
-- previously posted. This is used to ensure that such groups
-- of messages are treated as a unit. The \ character must be
-- the first character of the message text.
-- Insertion character | (vertical bar, non-serious error)
-- By default, error messages (other than warning messages) are
-- considered to be fatal error messages which prevent expansion
-- or generation of code in the presence of the -gnatQ switch.
-- If the insertion character | appears, the message is considered
-- to be non-serious, and does not cause Serious_Errors_Detected
-- to be incremented (so expansion is not prevented by such a msg).
-- Global Values Used for Error Message Insertions --
-- The following global variables are essentially additional parameters
-- passed to the error message routine for insertion sequences described
-- above. The reason these are passed globally is that the insertion
-- mechanism is essentially an untyped one in which the appropriate
-- variables are set dependingon the specific insertion characters used.
Error_Msg_Col : Column_Number renames Err_Vars.Error_Msg_Col;
-- Column for @ insertion character in message
Error_Msg_Uint_1 : Uint renames Err_Vars.Error_Msg_Uint_1;
Error_Msg_Uint_2 : Uint renames Err_Vars.Error_Msg_Uint_2;
-- Uint values for ^ insertion characters in message
Error_Msg_Sloc : Source_Ptr renames Err_Vars.Error_Msg_Sloc;
-- Source location for # insertion character in message
Error_Msg_Name_1 : Name_Id renames Err_Vars.Error_Msg_Name_1;
Error_Msg_Name_2 : Name_Id renames Err_Vars.Error_Msg_Name_2;
Error_Msg_Name_3 : Name_Id renames Err_Vars.Error_Msg_Name_3;
-- Name_Id values for % insertion characters in message
Error_Msg_Unit_1 : Name_Id renames Err_Vars.Error_Msg_Unit_1;
Error_Msg_Unit_2 : Name_Id renames Err_Vars.Error_Msg_Unit_2;
-- Name_Id values for $ insertion characters in message
Error_Msg_Node_1 : Node_Id renames Err_Vars.Error_Msg_Node_1;
Error_Msg_Node_2 : Node_Id renames Err_Vars.Error_Msg_Node_2;
-- Node_Id values for & insertion characters in message
Error_Msg_Qual_Level : Int renames Err_Vars.Error_Msg_Qual_Level;
-- Number of levels of qualification required for type name (see the
-- description of the } insertion character. Note that this value does
-- note get reset by any Error_Msg call, so the caller is responsible
-- for resetting it.
-- Format of Messages and Manual Quotation Control --
-- Messages are generally all in lower case, except for inserted names
-- and appear in one of the following three forms:
-- error: text
-- warning: text
-- The prefixes error and warning are supplied automatically (depending
-- on the use of the ? insertion character), and the call to the error
-- message routine supplies the text. The "error: " prefix is omitted
-- in brief error message formats.
-- Reserved Ada keywords in the message are in the default keyword case
-- (determined from the given source program), surrounded by quotation
-- marks. This is achieved by spelling the reserved word in upper case
-- letters, which is recognized as a request for insertion of quotation
-- marks by the error text processor. Thus for example:
-- Error_Msg_AP ("IS expected");
-- would result in the output of one of the following:
-- error: "is" expected
-- error: "IS" expected
-- error: "Is" expected
-- the choice between these being made by looking at the casing convention
-- used for keywords (actually the first compilation unit keyword) in the
-- source file.
-- In the case of names, the default mode for the error text processor
-- is to surround the name by quotation marks automatically. The case
-- used for the identifier names is taken from the source program where
-- possible, and otherwise is the default casing convention taken from
-- the source file usage.
-- In some cases, better control over the placement of quote marks is
-- required. This is achieved using manual quotation mode. In this mode,
-- one or more insertion sequences is surrounded by backquote characters.
-- The backquote characters are output as double quote marks, and normal
-- automatic insertion of quotes is suppressed between the double quotes.
-- For example:
-- Error_Msg_AP ("`END &;` expected");
-- generates a message like
-- error: "end Open_Scope;" expected
-- where the node specifying the name Open_Scope has been stored in
-- Error_Msg_Node_1 prior to the call. The great majority of error
-- messages operates in normal quotation mode.
-- Note: the normal automatic insertion of spaces before insertion
-- sequences (such as those that come from & and %) is suppressed in
-- manual quotation mode, so blanks, if needed as in the above example,
-- must be explicitly present.
-- Message ID Definitions --
subtype Error_Msg_Id is Erroutc.Error_Msg_Id;
function "=" (Left, Right : Error_Msg_Id) return Boolean
renames Erroutc."=";
-- A type used to represent specific error messages. Used by the clients
-- of this package only in the context of the Get_Error_Id and
-- Change_Error_Text subprograms.
No_Error_Msg : constant Error_Msg_Id := Erroutc.No_Error_Msg;
-- A constant which is different from any value returned by Get_Error_Id.
-- Typically used by a client to indicate absense of a saved Id value.
function Get_Msg_Id return Error_Msg_Id renames Erroutc.Get_Msg_Id;
-- Returns the Id of the message most recently posted using one of the
-- Error_Msg routines.
function Get_Location (E : Error_Msg_Id) return Source_Ptr
renames Erroutc.Get_Location;
-- Returns the flag location of the error message with the given id E.
-- List Pragmas Table --
-- When a pragma Page or pragma List is encountered by the parser, an
-- entry is made in the following table. This table is then used to
-- control the full listing if one is being generated. Note that the
-- reason we do the processing in the parser is so that we get proper
-- listing control even in syntax check only mode.
type List_Pragma_Type is (List_On, List_Off, Page);
type List_Pragma_Record is record
Ptyp : List_Pragma_Type;
Ploc : Source_Ptr;
end record;
-- Note: Ploc points to the terminating semicolon in the List_Off and
-- Page cases, and to the pragma keyword for List_On. In the case of
-- a pragma List_Off, a List_On entry is also made in the table,
-- pointing to the pragma keyword. This ensures that, as required,
-- a List (Off) pragma is listed even in list off mode.
package List_Pragmas is new Table.Table (
Table_Component_Type => List_Pragma_Record,
Table_Index_Type => Int,
Table_Low_Bound => 1,
Table_Initial => 50,
Table_Increment => 200,
Table_Name => "List_Pragmas");
-- Ignore_Errors Feature --
-- In certain cases, notably for optional subunits, the compiler operates
-- in a mode where errors are to be ignored, and the whole unit is to be
-- considered as not present. To implement this we provide the following
-- flag to enable special handling, where error messages are suppressed,
-- but the Fatal_Error flag will still be set in the normal manner.
Ignore_Errors_Enable : Nat := 0;
-- Triggering switch. If non-zero, then ignore errors mode is activated.
-- This is a counter to allow convenient nesting of enable/disable.
-- Error Output Subprograms --
procedure Initialize;
-- Initializes for output of error messages. Must be called for each
-- source file before using any of the other routines in the package.
procedure Finalize;
-- Finalize processing of error messages for one file and output message
-- indicating the number of detected errors.
procedure Error_Msg (Msg : String; Flag_Location : Source_Ptr);
-- Output a message at specified location. Can be called from the parser
-- or the semantic analyzer.
procedure Error_Msg_S (Msg : String);
-- Output a message at current scan pointer location. This routine can be
-- called only from the parser, since it references Scan_Ptr.
procedure Error_Msg_AP (Msg : String);
-- Output a message just after the previous token. This routine can be
-- called only from the parser, since it references Prev_Token_Ptr.
procedure Error_Msg_BC (Msg : String);
-- Output a message just before the current token. Note that the important
-- difference between this and the previous routine is that the BC case
-- posts a flag on the current line, whereas AP can post a flag at the
-- end of the preceding line. This routine can be called only from the
-- parser, since it references Token_Ptr.
procedure Error_Msg_SC (Msg : String);
-- Output a message at the start of the current token, unless we are at
-- the end of file, in which case we always output the message after the
-- last real token in the file. This routine can be called only from the
-- parser, since it references Token_Ptr.
procedure Error_Msg_SP (Msg : String);
-- Output a message at the start of the previous token. This routine can
-- be called only from the parser, since it references Prev_Token_Ptr.
procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id);
-- Output a message at the Sloc of the given node. This routine can be
-- called from the parser or the semantic analyzer, although the call
-- from the latter is much more common (and is the most usual way of
-- generating error messages from the analyzer). The message text may
-- contain a single & insertion, which will reference the given node.
-- The message is suppressed if the node N already has a message posted,
-- or if it is a warning and warnings and N is an entity node for which
-- warnings are suppressed.
procedure Error_Msg_F (Msg : String; N : Node_Id);
-- Similar to Error_Msg_N except that the message is placed on the
-- first node of the construct N (First_Node (N)).
procedure Error_Msg_NE
(Msg : String;
N : Node_Or_Entity_Id;
E : Node_Or_Entity_Id);
-- Output a message at the Sloc of the given node N, with an insertion of
-- the name from the given entity node E. This is used by the semantic
-- routines, where this is a common error message situation. The Msg
-- text will contain a & or } as usual to mark the insertion point.
-- This routine can be called from the parser or the analyzer.
procedure Error_Msg_FE
(Msg : String;
N : Node_Id;
E : Node_Or_Entity_Id);
-- Same as Error_Msg_NE, except that the message is placed on the first
-- node of the construct N (First_Node (N)).
procedure Error_Msg_NEL
(Msg : String;
N : Node_Or_Entity_Id;
E : Node_Or_Entity_Id;
Flag_Location : Source_Ptr);
-- Exactly the same as Error_Msg_NE, except that the flag is placed at
-- the specified Flag_Location instead of at Sloc (N).
procedure Error_Msg_NW
(Eflag : Boolean;
Msg : String;
N : Node_Or_Entity_Id);
-- This routine is used for posting a message conditionally. The message
-- is posted (with the same effect as Error_Msg_N (Msg, N) if and only
-- if Eflag is True and if the node N is within the main extended source
-- unit. Typically this is a warning mode flag.
procedure Change_Error_Text (Error_Id : Error_Msg_Id; New_Msg : String);
-- The error message text of the message identified by Id is replaced by
-- the given text. This text may contain insertion characters in the
-- usual manner, and need not be the same length as the original text.
function First_Node (C : Node_Id) return Node_Id;
-- Given a construct C, finds the first node in the construct, i.e. the
-- one with the lowest Sloc value. This is useful in placing error msgs.
procedure Purge_Messages (From : Source_Ptr; To : Source_Ptr)
renames Erroutc.Purge_Messages;
-- All error messages whose location is in the range From .. To (not
-- including the end points) will be deleted from the error listing.
procedure Remove_Warning_Messages (N : Node_Id);
-- Remove any warning messages corresponding to the Sloc of N or any
-- of its descendent nodes. No effect if no such warnings.
procedure Remove_Warning_Messages (L : List_Id);
-- Remove warnings on all elements of a list.
procedure Set_Ignore_Errors (To : Boolean);
-- Following a call to this procedure with To=True, all error calls are
-- ignored. A call with To=False restores the default treatment in which
-- error calls are treated as usual (and as described in this spec).
procedure Set_Warnings_Mode_Off (Loc : Source_Ptr)
renames Erroutc.Set_Warnings_Mode_Off;
-- Called in response to a pragma Warnings (Off) to record the source
-- location from which warnings are to be turned off.
procedure Set_Warnings_Mode_On (Loc : Source_Ptr)
renames Erroutc.Set_Warnings_Mode_On;
-- Called in response to a pragma Warnings (On) to record the source
-- location from which warnings are to be turned back on.
function Compilation_Errors return Boolean
renames Erroutc.Compilation_Errors;
-- Returns true if errors have been detected, or warnings in -gnatwe
-- (treat warnings as errors) mode.
procedure Error_Msg_CRT (Feature : String; N : Node_Id);
-- Posts a non-fatal message on node N saying that the feature
-- identified by the Feature argument is not supported in either
-- configurable run-time mode or no run-time mode (as appropriate).
-- In the former case, the name of the library is output if available.
procedure dmsg (Id : Error_Msg_Id) renames Erroutc.dmsg;
-- Debugging routine to dump an error message
-- Utility Interface for Back End --
-- The following subprograms can be used by the back end for the purposes
-- of concocting error messages that are not output via Errout, e.g. the
-- messages generated by the gcc back end.
procedure Set_Identifier_Casing
(Identifier_Name : System.Address;
File_Name : System.Address);
-- The identifier is a null terminated string that represents the name
-- of an identifier appearing in the source program. File_Name is a null
-- terminated string giving the corresponding file name for the identifier
-- as obtained from the front end by the use of Full_Debug_Name to the
-- source file referenced by the corresponding source location value.
-- On return, the name is in Name_Buffer, null terminated with Name_Len
-- set. This name is the identifier name as passed, cased according to
-- the default identifier casing for the given file.
end Errout;