------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E R R O U T -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2004 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 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). ---------------------------------------- -- Specialization of Messages for VMS -- ---------------------------------------- -- Some messages mention gcc-style switch names. When using an OpenVMS -- host, such switch names must be converted to their corresponding VMS -- qualifer. The following table controls this translation. In each case -- the original message must contain the string "-xxx switch", where xxx -- is the Gname? entry from below, and this string will be replaced by -- "/yyy qualifier", where yyy is the corresponding Vname? entry. Gname1 : aliased constant String := "fno-strict-aliasing"; Vname1 : aliased constant String := "OPTIMIZE=NO_STRICT_ALIASING"; Gname2 : aliased constant String := "gnatX"; Vname2 : aliased constant String := "EXTENSIONS_ALLOWED"; Gname3 : aliased constant String := "gnatW"; Vname3 : aliased constant String := "WIDE_CHARACTER_ENCODING"; Gname4 : aliased constant String := "gnatf"; Vname4 : aliased constant String := "REPORT_ERRORS=FULL"; Gname5 : aliased constant String := "gnat05"; Vname5 : aliased constant String := "05"; type Cstring_Ptr is access constant String; Gnames : array (Nat range <>) of Cstring_Ptr := (Gname1'Access, Gname2'Access, Gname3'Access, Gname4'Access, Gname5'Access); Vnames : array (Nat range <>) of Cstring_Ptr := (Vname1'Access, Vname2'Access, Vname3'Access, Vname4'Access, Vname5'Access); ----------------------------------------------------- -- 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. function First_Sloc (N : Node_Id) return Source_Ptr; -- Given the node for an expression, return a source pointer value that -- points to the start of the first token in the expression. In the case -- where the expression is parenthesized, an attempt is made to include -- the parentheses (i.e. to return the location of the initial paren). 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;