------------------------------------------------------------------------------
--                                                                          --
--                           GPR PROJECT MANAGER                            --
--                                                                          --
--          Copyright (C) 2004-2017, Free Software Foundation, Inc.         --
--                                                                          --
-- This library is free software;  you can redistribute it and/or modify it --
-- under terms of the  GNU General Public License  as published by the Free --
-- Software  Foundation;  either version 3,  or (at your  option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY;  without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE.                            --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
------------------------------------------------------------------------------

--  This package contains various subprograms used by the builders, in
--  particular those subprograms related to project management and build
--  queue management.

with GNAT.OS_Lib; use GNAT.OS_Lib;
with GNAT.Table;

with GPR;        use GPR;
with GPR.ALI;
with GPR.Snames; use GPR.Snames;
with GPR.Tree;

package Gpr_Build_Util is

   Multi_Unit_Index_Character : constant Character := '~';
   --  The character before the index of the unit in a multi-unit source in ALI
   --  and object file names.

   Root_Environment : GPR.Tree.Environment;
   --  The environment coming from environment variables and command line
   --  switches. When we do not have an aggregate project, this is used for
   --  parsing the project tree. When we have an aggregate project, this is
   --  used to parse the aggregate project; the latter then generates another
   --  environment (with additional external values and project path) to parse
   --  the aggregated projects.

   On_Windows : constant Boolean := Directory_Separator = '\';
   --  True when on Windows

   Source_Info_Option : constant String := "--source-info=";
   --  Switch to indicate the source info file

   Subdirs_Option : constant String := "--subdirs=";
   --  Switch used to indicate that the real directories (object, exec,
   --  library, ...) are subdirectories of those in the project file.

   Relocate_Build_Tree_Option : constant String := "--relocate-build-tree";
   --  Switch to build out-of-tree. In this context the object, exec and
   --  library directories are relocated to the current working directory
   --  or the directory specified as parameter to this option.

   Root_Dir_Option : constant String := "--root-dir";
   --  The root directory under which all artifacts (objects, library, ali)
   --  directory are to be found for the current compilation. This directory
   --  will be used to relocate artifacts based on this directory. If this
   --  option is not specificed the default value is the directory of the
   --  main project.

   Unchecked_Shared_Lib_Imports : constant String :=
                                    "--unchecked-shared-lib-imports";
   --  Command line switch to allow shared library projects to import projects
   --  that are not shared library projects.

   Single_Compile_Per_Obj_Dir_Switch : constant String :=
                                         "--single-compile-per-obj-dir";
   --  Switch to forbid simultaneous compilations for the same object directory
   --  when project files are used.

   Create_Map_File_Switch : constant String := "--create-map-file";
   --  Switch to create a map file when an executable is linked

   No_Exit_Message_Option : constant String := "--no-exit-message";
   --  Switch to suppress exit error message when there are compilation
   --  failures. This is useful when a tool, such as gnatprove, silently calls
   --  the builder and does not want to pollute its output with error messages
   --  coming from the builder. This is an internal switch.

   Keep_Temp_Files_Option : constant String := "--keep-temp-files";
   --  Switch to suppress deletion of temp files created by the builder.
   --  Note that debug switch -gnatdn also has this effect.

   package Directories is new GNAT.Table
     (Table_Component_Type => Path_Name_Type,
      Table_Index_Type     => Integer,
      Table_Low_Bound      => 1,
      Table_Initial        => 200,
      Table_Increment      => 100);
   --  Table of all the source or object directories, filled up by
   --  Get_Directories.

   procedure Add
     (Option : String_Access;
      To     : in out String_List_Access;
      Last   : in out Natural);
   procedure Add
     (Option : String;
      To     : in out String_List_Access;
      Last   : in out Natural);
   --  Add a string to a list of strings

   function Lib_File_Name
     (Source_File : File_Name_Type;
      Munit_Index : Nat := 0) return File_Name_Type;
   --  Returns the ALI file name for source Source_File with multi-unit index
   --  Munit_Index.

   function Create_Binder_Mapping_File
     (Project_Tree : Project_Tree_Ref) return Path_Name_Type;
   --  Create a binder mapping file and returns its path name

   function Base_Name_Index_For
     (Main            : String;
      Main_Index      : Int;
      Index_Separator : Character) return File_Name_Type;
   --  Returns the base name of Main, without the extension, followed by the
   --  Index_Separator followed by the Main_Index if it is non-zero.

   procedure Inform (N : Name_Id := No_Name; Msg : String);
   procedure Inform (N : File_Name_Type; Msg : String);
   --  Prints out the program name followed by a colon, N and S

   function Check_Source_Info_In_ALI
     (The_ALI      : ALI.ALI_Id;
      Tree         : Project_Tree_Ref) return Name_Id;
   --  Check whether all file references in ALI are still valid (i.e. the
   --  source files are still associated with the same units). Return the name
   --  of the unit if everything is still valid. Return No_Name otherwise.

   function Is_External_Assignment
     (Env  : GPR.Tree.Environment;
      Argv : String) return Boolean;
   --  Verify that an external assignment switch is syntactically correct
   --
   --  Correct forms are:
   --
   --      -Xname=value
   --      -X"name=other value"
   --
   --  Assumptions: 'First = 1, Argv (1 .. 2) = "-X"
   --
   --  When this function returns True, the external assignment has been
   --  entered by a call to GPR.Ext.Add, so that in a project file,
   --  External ("name") will return "value".

   type Name_Ids is array (Positive range <>) of Name_Id;
   No_Names : constant Name_Ids := (1 .. 0 => No_Name);
   --  Name_Ids is used for list of language names in procedure Get_Directories
   --  below.

   Ada_Only : constant Name_Ids := (1 => Name_Ada);
   --  Used to invoke Get_Directories in gnatmake

   type Activity_Type is (Compilation, Executable_Binding, SAL_Binding);

   procedure Get_Directories
     (Project_Tree : Project_Tree_Ref;
      For_Project  : Project_Id;
      Activity     : Activity_Type;
      Languages    : Name_Ids);
   --  Put in table Directories the source (when Sources is True) or
   --  object/library (when Sources is False) directories of project
   --  For_Project and of all the project it imports directly or indirectly.
   --  The source directories of imported projects are only included if one
   --  of the declared languages is in the list Languages.

   function Aggregate_Libraries_In (Tree : Project_Tree_Ref) return Boolean;
   --  Return True iff there is one or more aggregate library projects in
   --  the project tree Tree.

   procedure Write_Path_File (FD : File_Descriptor);
   --  Write in the specified open path file the directories in table
   --  Directories, then closed the path file.

   function Path_Or_File_Name (Path : Path_Name_Type) return String;
   --  Returns a file name if -df is used, otherwise return a path name

   function Is_Static (Project : Project_Id) return Boolean
       is (Project.Library_Kind = Static or else Project.Library_Kind =
             Static_Pic);
   --  Return True if the library project correspond to a static library.

   function Unescape (Path : String) return String;
   --  On platforms other than Windows, remove the characters '\'.

   --------------
   -- Switches --
   --------------

   generic
      with function Add_Switch
        (Switch      : String;
         For_Lang    : Name_Id;
         For_Builder : Boolean;
         Has_Global_Compilation_Switches : Boolean) return Boolean;
      --  For_Builder is true if we have a builder switch. This function
      --  should return True in case of success (the switch is valid),
      --  False otherwise. The error message will be displayed by
      --  Compute_Builder_Switches itself.
      --
      --  Has_Global_Compilation_Switches is True if the attribute
      --  Global_Compilation_Switches is defined in the project.

   procedure Compute_Builder_Switches
     (Project_Tree     : Project_Tree_Ref;
      Env              : in out GPR.Tree.Environment;
      Main_Project     : Project_Id;
      Only_For_Lang    : Name_Id := No_Name);
   --  Compute the builder switches and global compilation switches. Every time
   --  a switch is found in the project, it is passed to Add_Switch. You can
   --  provide a value for Only_For_Lang so that we only look for this language
   --  when parsing the global compilation switches.

   -----------------------
   -- Project_Tree data --
   -----------------------

   --  The following types are specific to builders, and associated with each
   --  of the loaded project trees.

   type Binding_Data_Record;
   type Binding_Data is access Binding_Data_Record;
   type Binding_Data_Record is record
      Language           : Language_Ptr;
      Language_Name      : Name_Id;
      Binder_Driver_Name : File_Name_Type;
      Binder_Driver_Path : String_Access;
      Binder_Prefix      : Name_Id;
      Next               : Binding_Data;
   end record;
   --  Data for a language that have a binder driver

   type Builder_Project_Tree_Data is new Project_Tree_Appdata with record
      Binding : Binding_Data;

      There_Are_Binder_Drivers : Boolean := False;
      --  True when there is a binder driver. Set by Get_Configuration when
      --  an attribute Language_Processing'Binder_Driver is declared.
      --  Reset to False if there are no sources of the languages with binder
      --  drivers.

      Number_Of_Mains : Natural := 0;
      --  Number of main units in this project tree

      Closure_Needed : Boolean := False;
      --  If True, we need to add the closure of the file we just compiled to
      --  the queue. If False, it is assumed that all files are already on the
      --  queue so we do not waste time computing the closure.

      Need_Compilation : Boolean := True;
      Need_Binding     : Boolean := True;
      Need_Linking     : Boolean := True;
      --  Which of the compilation phases are needed for this project tree
   end record;
   type Builder_Data_Access is access all Builder_Project_Tree_Data;

   procedure Free (Data : in out Builder_Project_Tree_Data);
   --  Free all memory allocated for Data

   function Builder_Data (Tree : Project_Tree_Ref) return Builder_Data_Access;
   --  Return (allocate if needed) tree-specific data

   procedure Compute_Compilation_Phases
     (Tree                  : Project_Tree_Ref;
      Root_Project          : Project_Id;
      Option_Unique_Compile : Boolean := False;   --  Was "-u" specified ?
      Option_Compile_Only   : Boolean := False;   --  Was "-c" specified ?
      Option_Bind_Only      : Boolean := False;
      Option_Link_Only      : Boolean := False);
   --  Compute which compilation phases will be needed for Tree. This also does
   --  the computation for aggregated trees. This also check whether we'll need
   --  to check the closure of the files we have just compiled to add them to
   --  the queue.

   -----------
   -- Mains --
   -----------

   --  Package Mains is used to store the mains specified on the command line
   --  and to retrieve them when a project file is used, to verify that the
   --  files exist and that they belong to a project file.

   --  Mains are stored in a table. An index is used to retrieve the mains
   --  from the table.

   type Main_Info is record
      File      : File_Name_Type;  --  Always canonical casing
      Index     : Int := 0;
      Location  : Source_Ptr := No_Location;

      Source    : GPR.Source_Id := No_Source;
      Project   : Project_Id;
      Tree      : Project_Tree_Ref;
   end record;

   No_Main_Info : constant Main_Info :=
                    (No_File, 0, No_Location, No_Source, No_Project, null);

   package Mains is
      procedure Add_Main
        (Name     : String;
         Index    : Int := 0;
         Location : Source_Ptr := No_Location;
         Project  : Project_Id := No_Project;
         Tree     : Project_Tree_Ref := null);
      --  Add one main to the table. This is in general used to add the main
      --  files specified on the command line. Index is used for multi-unit
      --  source files, and indicates which unit in the source is concerned.
      --  Location is the location within the project file (if a project file
      --  is used). Project and Tree indicate to which project the main should
      --  belong. In particular, for aggregate projects, this isn't necessarily
      --  the main project tree. These can be set to No_Project and null when
      --  not using projects.

      procedure Delete;
      --  Empty the table

      procedure Reset;
      --  Reset the cursor to the beginning of the table

      procedure Set_Multi_Unit_Index
        (Project_Tree : Project_Tree_Ref := null;
         Index        : Int := 0);
      --  If a single main file was defined, this subprogram indicates which
      --  unit inside it is the main (case of a multi-unit source files).
      --  Errors are raised if zero or more than one main file was defined,
      --  and Index is non-zaero. This subprogram is used for the handling
      --  of the command line switch.

      function Next_Main return String;
      function Next_Main return Main_Info;
      --  Moves the cursor forward and returns the new current entry. Returns
      --  No_Main_Info there are no more mains in the table.

      function Number_Of_Mains (Tree : Project_Tree_Ref) return Natural;
      --  Returns the number of mains in this project tree (if Tree is null, it
      --  returns the total number of project trees)

      procedure Fill_From_Project
        (Root_Project : Project_Id;
         Project_Tree : Project_Tree_Ref);
      --  If no main was already added (presumably from the command line), add
      --  the main units from root_project (or in the case of an aggregate
      --  project from all the aggregated projects).

      procedure Complete_Mains
        (Flags          : Processing_Flags;
         Root_Project   : Project_Id;
         Project_Tree   : Project_Tree_Ref;
         Unique_Compile : Boolean := False);
      --  If some main units were already added from the command line, check
      --  that they all belong to the root project, and that they are full
      --  paths rather than (partial) base names (e.g. no body suffix was
      --  specified).

   end Mains;

   -----------
   -- Queue --
   -----------

   package Queue is

      --  The queue of sources to be checked for compilation. There can be a
      --  single such queue per application.

      type Source_Info is
         record
            Tree    : Project_Tree_Ref := No_Project_Tree;
            Id      : Source_Id        := No_Source;
            Closure : Boolean          := False;
         end record;
      --  Information about files stored in the queue

      No_Source_Info : constant Source_Info := (null, null, False);

      procedure Initialize
        (Queue_Per_Obj_Dir : Boolean;
         Force             : Boolean := False);
      --  Initialize the queue
      --
      --  Queue_Per_Obj_Dir matches the --single-compile-per-obj-dir switch:
      --  when True, there cannot be simultaneous compilations with the object
      --  files in the same object directory when project files are used.
      --
      --  Nothing is done if Force is False and the queue was already
      --  initialized.

      function Is_Empty return Boolean;
      --  Returns True if the queue is empty

      function Is_Virtually_Empty return Boolean;
      --  Returns True if queue is empty or if all object directories are busy

      procedure Insert (Source  : Source_Info; With_Roots : Boolean := False);
      function Insert
        (Source  : Source_Info; With_Roots : Boolean := False) return Boolean;
      --  Insert source in the queue. The second version returns False if the
      --  Source was already marked in the queue. If With_Roots is True and the
      --  source is in Format_Gprbuild mode (ie with a project), this procedure
      --  also includes the "Roots" for this main, ie all the other files that
      --  must be included in the library or binary (in particular to combine
      --  Ada and C files connected through pragma Export/Import). When the
      --  roots are computed, they are also stored in the corresponding
      --  Source_Id for later reuse by the binder.

      procedure Insert_Project_Sources
        (Project        : Project_Id;
         Project_Tree   : Project_Tree_Ref;
         All_Projects   : Boolean;
         Unique_Compile : Boolean);
      --  Insert all the compilable sources of the project in the queue. If
      --  All_Project is true, then all sources from imported projects are also
      --  inserted. Unique_Compile should be true if "-u" was specified on the
      --  command line: if True and some files were given on the command line),
      --  only those files will be compiled (so Insert_Project_Sources will do
      --  nothing). If True and no file was specified on the command line, all
      --  files of the project(s) will be compiled. This procedure also
      --  processed aggregated projects.

      procedure Insert_Withed_Sources_For
        (The_ALI               : ALI.ALI_Id;
         Project_Tree          : Project_Tree_Ref;
         Excluding_Shared_SALs : Boolean := False);
      --  Insert in the queue those sources withed by The_ALI, if there are not
      --  already in the queue and Only_Interfaces is False or they are part of
      --  the interfaces of their project.

      procedure Extract
        (Found  : out Boolean;
         Source : out Source_Info);
      --  Get the first source that can be compiled from the queue. If no
      --  source may be compiled, sets Found to False. In this case, the value
      --  for Source is undefined.

      function Size return Natural;
      --  Return the total size of the queue, including the sources already
      --  extracted.

      function Processed return Natural;
      --  Return the number of source in the queue that have aready been
      --  processed.

      procedure Set_Obj_Dir_Busy (Obj_Dir : Path_Name_Type);
      procedure Set_Obj_Dir_Free (Obj_Dir : Path_Name_Type);
      --  Mark Obj_Dir as busy or free (see the parameter to Initialize)

      function Element (Rank : Positive) return File_Name_Type;
      --  Get the file name for element of index Rank in the queue

   end Queue;

end Gpr_Build_Util;
