------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E R R O U T -- -- -- -- S p e c -- -- -- -- -- -- Copyright (C) 1992-2001 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 Table; with Types; use Types; with Uintp; use Uintp; package Errout is Serious_Errors_Detected : Nat; -- 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; -- 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; -- Number of warnings detected 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; -- 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 := 0; -- 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; -- 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 ! (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. -- 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; -- Column for @ insertion character in message Error_Msg_Uint_1 : Uint; Error_Msg_Uint_2 : Uint; -- Uint values for ^ insertion characters in message Error_Msg_Sloc : Source_Ptr; -- Source location for # insertion character in message Error_Msg_Name_1 : Name_Id; Error_Msg_Name_2 : Name_Id; Error_Msg_Name_3 : Name_Id; -- Name_Id values for % insertion characters in message Error_Msg_Unit_1 : Name_Id; Error_Msg_Unit_2 : Name_Id; -- Name_Id values for $ insertion characters in message Error_Msg_Node_1 : Node_Id; Error_Msg_Node_2 : Node_Id; -- Node_Id values for & insertion characters in message Error_Msg_Qual_Level : Int := 0; -- 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. Warn_On_Instance : Boolean := False; -- Normally if a warning is generated in a generic template from the -- analysis of the template, then the warning really belongs in the -- template, and the default value of False for this Boolean achieves -- that effect. If Warn_On_Instance is set True, then the warnings are -- generated on the instantiation (referring to the template) rather -- than on the template itself. ----------------------------------------------------- -- 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 -- ---------------------------- type Error_Msg_Id is new Int; -- 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 := 0; -- 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; -- 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; -- 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_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_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 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. procedure Purge_Messages (From : Source_Ptr; To : Source_Ptr); -- 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 Set_Warnings_Mode_Off (Loc : Source_Ptr); -- 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); -- 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; -- Returns true if errors have been detected, or warnings in -gnatwe -- (treat warnings as errors) mode. procedure dmsg (Id : Error_Msg_Id); -- Debugging routine to dump an error message end Errout;