------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- A L I . U T I L -- -- -- -- 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 child unit provides utility data structures and procedures used -- for manipulation of ALI data by the gnatbind and gnatmake. package ALI.Util is ----------------------- -- Source File Table -- ----------------------- -- A source file table entry is built for every source file that is -- in the source dependency table of any of the ALI files that make -- up the current program. No_Source_Id : constant Source_Id := Source_Id'First; -- Special value indicating no Source table entry First_Source_Entry : constant Source_Id := No_Source_Id + 1; -- Id of first actual entry in table type Source_Record is record Sfile : File_Name_Type; -- Name of source file Stamp : Time_Stamp_Type; -- Time stamp value. If Check_Source_Files is set and the source -- file is located, then Stamp is set from the source file. Otherwise -- Stamp is set from the latest stamp value found in any of the -- ALI files for the current program. Source_Found : Boolean; -- This flag is set to True if the corresponding source file was -- located and the Stamp value was set from the actual source file. -- It is always false if Check_Source_Files is not set. All_Timestamps_Match : Boolean; -- This flag is set only if all files referencing this source file -- have a matching time stamp, and also, if Source_Found is True, -- then the stamp of the source file also matches. If this flag is -- True, then checksums for this file are never referenced. We only -- use checksums if there are time stamp mismatches. All_Checksums_Match : Boolean; -- This flag is set only if all files referencing this source file -- have checksums, and if all these checksums match. If this flag -- is set to True, then the binder will ignore a timestamp mismatch. -- An absent checksum causes this flag to be set False, and a mismatch -- of checksums also causes it to be set False. The checksum of the -- actual source file (if Source_Found is True) is included only if -- All_Timestamps_Match is False (since checksums are only interesting -- if we have time stamp mismatches, and we want to avoid computing the -- checksum of the source file if it is not needed.) Checksum : Word; -- If no dependency line has a checksum for this source file (i.e. the -- corresponding entries in the source dependency records all have the -- Checksum_Present flag set False), then this field is undefined. If -- at least one dependency entry has a checksum present, then this -- field contains one of the possible checksum values that has been -- seen. This is used to set All_Checksums_Match properly. end record; package Source is new Table.Table ( Table_Component_Type => Source_Record, Table_Index_Type => Source_Id, Table_Low_Bound => First_Source_Entry, Table_Initial => 1000, Table_Increment => 200, Table_Name => "Source"); procedure Initialize_ALI_Source; -- Initialize Source table -------------------------------------------------- -- Subprograms for Manipulating ALI Information -- -------------------------------------------------- procedure Read_ALI (Id : ALI_Id); -- Process an ALI file which has been read and scanned by looping -- through all withed units in the ALI file; checking if they have -- been processed; and for each that hasn't, reading, scanning, and -- recursively processing. procedure Set_Source_Table (A : ALI_Id); -- Build source table entry corresponding to the ALI file whose id is A. procedure Set_Source_Table; -- Build the entire source table. function Time_Stamp_Mismatch (A : ALI_Id) return File_Name_Type; -- Looks in the Source_Table and checks time stamp mismatches between -- the sources there and the sources in the Sdep section of ali file whose -- id is A. If no time stamp mismatches are found No_File is returned. -- Otherwise return the first file for which there is a mismatch. -- Note that in check source files mode (Check_Source_Files = True), the -- time stamp in the Source_Table should be the actual time stamp of the -- source files. In minimal recompilation mode (Minimal_Recompilation set -- to True, no mismatch is found if the file's timestamp has not changed. -------------------------------------------- -- Subprograms for manipulating checksums -- -------------------------------------------- Checksum_Error : constant Word := 16#FFFF_FFFF#; -- This value is used to indicate an error in computing the checksum. -- When comparing checksums for smart recompilation, the CRC_Error -- value is never considered to match. This could possibly result -- in a false negative, but that is never harmful, it just means -- that in unusual cases an unnecessary recompilation occurs. function Get_File_Checksum (Fname : Name_Id) return Word; -- Compute checksum for the given file. As far as possible, this circuit -- computes exactly the same value computed by the compiler, but it does -- not matter if it gets it wrong in marginal cases, since the only result -- is to miss some smart recompilation cases, correct functioning is not -- affected by a miscomputation. Returns Checksum_Error if the file is -- missing or has an error. function Checksums_Match (Checksum1, Checksum2 : Word) return Boolean; pragma Inline (Checksums_Match); -- Returns True if Checksum1 and Checksum2 have the same value and are -- not equal to Checksum_Error, returns False in all other cases. This -- routine must always be used to compare for checksum equality, to -- ensure that the case of Checksum_Error is handled properly. end ALI.Util;