------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- L I B . L O A D -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2006, 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, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, USA. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Errout; use Errout; with Fname; use Fname; with Fname.UF; use Fname.UF; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Osint; use Osint; with Osint.C; use Osint.C; with Output; use Output; with Par; with Restrict; use Restrict; with Scn; use Scn; with Sinfo; use Sinfo; with Sinput; use Sinput; with Sinput.L; use Sinput.L; with Stand; use Stand; with Tbuild; use Tbuild; with Uname; use Uname; package body Lib.Load is ----------------------- -- Local Subprograms -- ----------------------- function From_Limited_With_Chain (Lim : Boolean) return Boolean; -- Check whether a possible circular dependence includes units that -- have been loaded through limited_with clauses, in which case there -- is no real circularity. function Spec_Is_Irrelevant (Spec_Unit : Unit_Number_Type; Body_Unit : Unit_Number_Type) return Boolean; -- The Spec_Unit and Body_Unit parameters are the unit numbers of the -- spec file that corresponds to the main unit which is a body. This -- function determines if the spec file is irrelevant and will be -- overridden by the body as described in RM 10.1.4(4). See description -- in "Special Handling of Subprogram Bodies" for further details. procedure Write_Dependency_Chain; -- This procedure is used to generate error message info lines that -- trace the current dependency chain when a load error occurs. ------------------------------- -- Create_Dummy_Package_Unit -- ------------------------------- function Create_Dummy_Package_Unit (With_Node : Node_Id; Spec_Name : Unit_Name_Type) return Unit_Number_Type is Unum : Unit_Number_Type; Cunit_Entity : Entity_Id; Cunit : Node_Id; Du_Name : Node_Or_Entity_Id; End_Lab : Node_Id; Save_CS : constant Boolean := Get_Comes_From_Source_Default; begin -- The created dummy package unit does not come from source Set_Comes_From_Source_Default (False); -- Normal package if Nkind (Name (With_Node)) = N_Identifier then Cunit_Entity := Make_Defining_Identifier (No_Location, Chars => Chars (Name (With_Node))); Du_Name := Cunit_Entity; End_Lab := New_Occurrence_Of (Cunit_Entity, No_Location); -- Child package else Cunit_Entity := Make_Defining_Identifier (No_Location, Chars => Chars (Selector_Name (Name (With_Node)))); Du_Name := Make_Defining_Program_Unit_Name (No_Location, Name => New_Copy_Tree (Prefix (Name (With_Node))), Defining_Identifier => Cunit_Entity); Set_Is_Child_Unit (Cunit_Entity); End_Lab := Make_Designator (No_Location, Name => New_Copy_Tree (Prefix (Name (With_Node))), Identifier => New_Occurrence_Of (Cunit_Entity, No_Location)); end if; Set_Scope (Cunit_Entity, Standard_Standard); Cunit := Make_Compilation_Unit (No_Location, Context_Items => Empty_List, Unit => Make_Package_Declaration (No_Location, Specification => Make_Package_Specification (No_Location, Defining_Unit_Name => Du_Name, Visible_Declarations => Empty_List, End_Label => End_Lab)), Aux_Decls_Node => Make_Compilation_Unit_Aux (No_Location)); -- Mark the dummy package as analyzed to prevent analysis of this -- (non-existent) unit in -gnatQ mode because at the moment the -- structure and attributes of this dummy package does not allow -- a normal analysis of this unit Set_Analyzed (Cunit); Units.Increment_Last; Unum := Units.Last; Units.Table (Unum) := ( Cunit => Cunit, Cunit_Entity => Cunit_Entity, Dependency_Num => 0, Dynamic_Elab => False, Error_Location => Sloc (With_Node), Expected_Unit => Spec_Name, Fatal_Error => True, Generate_Code => False, Has_RACW => False, Ident_String => Empty, Loading => False, Main_Priority => Default_Main_Priority, Munit_Index => 0, Serial_Number => 0, Source_Index => No_Source_File, Unit_File_Name => Get_File_Name (Spec_Name, Subunit => False), Unit_Name => Spec_Name, Version => 0); Set_Comes_From_Source_Default (Save_CS); Set_Error_Posted (Cunit_Entity); Set_Error_Posted (Cunit); return Unum; end Create_Dummy_Package_Unit; ----------------------------- -- From_Limited_With_Chain -- ----------------------------- function From_Limited_With_Chain (Lim : Boolean) return Boolean is begin -- True if the current load operation is through a limited_with clause if Lim then return True; -- Examine the Load_Stack to locate any previous Limited_with clause elsif Load_Stack.Last - 1 > Load_Stack.First then for U in Load_Stack.First .. Load_Stack.Last - 1 loop if Load_Stack.Table (U).From_Limited_With then return True; end if; end loop; end if; return False; end From_Limited_With_Chain; ---------------- -- Initialize -- ---------------- procedure Initialize is begin Units.Init; Load_Stack.Init; end Initialize; ------------------------ -- Initialize_Version -- ------------------------ procedure Initialize_Version (U : Unit_Number_Type) is begin Units.Table (U).Version := Source_Checksum (Source_Index (U)); end Initialize_Version; ---------------------- -- Load_Main_Source -- ---------------------- procedure Load_Main_Source is Fname : File_Name_Type; begin Load_Stack.Increment_Last; Load_Stack.Table (Load_Stack.Last) := (Main_Unit, False); -- Initialize unit table entry for Main_Unit. Note that we don't know -- the unit name yet, that gets filled in when the parser parses the -- main unit, at which time a check is made that it matches the main -- file name, and then the Unit_Name field is set. The Cunit and -- Cunit_Entity fields also get filled in later by the parser. Units.Increment_Last; Fname := Next_Main_Source; Units.Table (Main_Unit).Unit_File_Name := Fname; if Fname /= No_File then Main_Source_File := Load_Source_File (Fname); Current_Error_Source_File := Main_Source_File; Units.Table (Main_Unit) := ( Cunit => Empty, Cunit_Entity => Empty, Dependency_Num => 0, Dynamic_Elab => False, Error_Location => No_Location, Expected_Unit => No_Name, Fatal_Error => False, Generate_Code => False, Has_RACW => False, Ident_String => Empty, Loading => True, Main_Priority => Default_Main_Priority, Munit_Index => 0, Serial_Number => 0, Source_Index => Main_Source_File, Unit_File_Name => Fname, Unit_Name => No_Name, Version => Source_Checksum (Main_Source_File)); end if; end Load_Main_Source; --------------- -- Load_Unit -- --------------- function Load_Unit (Load_Name : Unit_Name_Type; Required : Boolean; Error_Node : Node_Id; Subunit : Boolean; Corr_Body : Unit_Number_Type := No_Unit; Renamings : Boolean := False; From_Limited_With : Boolean := False) return Unit_Number_Type is Calling_Unit : Unit_Number_Type; Uname_Actual : Unit_Name_Type; Unum : Unit_Number_Type; Unump : Unit_Number_Type; Fname : File_Name_Type; Src_Ind : Source_File_Index; -- Start of processing for Load_Unit begin -- If renamings are allowed and we have a child unit name, then we -- must first load the parent to deal with finding the real name. if Renamings and then Is_Child_Name (Load_Name) then Unump := Load_Unit (Load_Name => Get_Parent_Spec_Name (Load_Name), Required => Required, Subunit => False, Renamings => True, Error_Node => Error_Node); if Unump = No_Unit then return No_Unit; end if; -- If parent is a renaming, then we use the renamed package as -- the actual parent for the subsequent load operation. if Nkind (Parent (Cunit_Entity (Unump))) = N_Package_Renaming_Declaration then Uname_Actual := New_Child (Load_Name, Get_Unit_Name (Name (Parent (Cunit_Entity (Unump))))); -- Save the renaming entity, to establish its visibility when -- installing the context. The implicit with is on this entity, -- not on the package it renames. if Nkind (Error_Node) = N_With_Clause and then Nkind (Name (Error_Node)) = N_Selected_Component then declare Par : Node_Id := Name (Error_Node); begin while Nkind (Par) = N_Selected_Component and then Chars (Selector_Name (Par)) /= Chars (Cunit_Entity (Unump)) loop Par := Prefix (Par); end loop; -- Case of some intermediate parent is a renaming if Nkind (Par) = N_Selected_Component then Set_Entity (Selector_Name (Par), Cunit_Entity (Unump)); -- Case where the ultimate parent is a renaming else Set_Entity (Par, Cunit_Entity (Unump)); end if; end; end if; -- If the parent is not a renaming, then get its name (this may -- be different from the parent spec name obtained above because -- of renamings higher up in the hierarchy). else Uname_Actual := New_Child (Load_Name, Unit_Name (Unump)); end if; -- Here if unit to be loaded is not a child unit else Uname_Actual := Load_Name; end if; Fname := Get_File_Name (Uname_Actual, Subunit); if Debug_Flag_L then Write_Eol; Write_Str ("*** Load request for unit: "); Write_Unit_Name (Load_Name); if Required then Write_Str (" (Required = True)"); else Write_Str (" (Required = False)"); end if; Write_Eol; if Uname_Actual /= Load_Name then Write_Str ("*** Actual unit loaded: "); Write_Unit_Name (Uname_Actual); end if; end if; -- Capture error location if it is for the main unit. The idea is to -- post errors on the main unit location, not the most recent unit. -- Note: Unit_Name (Main_Unit) is not set if we are parsing gnat.adc. if Present (Error_Node) and then Unit_Name (Main_Unit) /= No_Name then -- It seems like In_Extended_Main_Source_Unit (Error_Node) would -- do the trick here, but that's wrong, it is much too early to -- call this routine. We are still in the parser, and the required -- semantic information is not established yet. So we base the -- judgment on unit names. Get_External_Unit_Name_String (Unit_Name (Main_Unit)); declare Main_Unit_Name : constant String := Name_Buffer (1 .. Name_Len); begin Get_External_Unit_Name_String (Unit_Name (Get_Source_Unit (Error_Node))); -- If the two names are identical, then for sure we are part -- of the extended main unit if Main_Unit_Name = Name_Buffer (1 .. Name_Len) then Load_Msg_Sloc := Sloc (Error_Node); -- If the load is called from a with_type clause, the error -- node is correct. elsif Nkind (Parent (Error_Node)) = N_With_Type_Clause then Load_Msg_Sloc := Sloc (Error_Node); -- Otherwise, check for the subunit case, and if so, consider -- we have a match if one name is a prefix of the other name. else if Nkind (Unit (Cunit (Main_Unit))) = N_Subunit or else Nkind (Unit (Cunit (Get_Source_Unit (Error_Node)))) = N_Subunit then Name_Len := Integer'Min (Name_Len, Main_Unit_Name'Length); if Name_Buffer (1 .. Name_Len) = Main_Unit_Name (1 .. Name_Len) then Load_Msg_Sloc := Sloc (Error_Node); end if; end if; end if; end; end if; -- If we are generating error messages, then capture calling unit if Present (Error_Node) then Calling_Unit := Get_Source_Unit (Error_Node); else Calling_Unit := No_Unit; end if; -- See if we already have an entry for this unit Unum := Main_Unit; while Unum <= Units.Last loop exit when Uname_Actual = Units.Table (Unum).Unit_Name; Unum := Unum + 1; end loop; -- Whether or not the entry was found, Unum is now the right value, -- since it is one more than Units.Last (i.e. the index of the new -- entry we will create) in the not found case. -- A special check is necessary in the unit not found case. If the unit -- is not found, but the file in which it lives has already been loaded, -- then we have the problem that the file does not contain the unit that -- is needed. We simply treat this as a file not found condition. -- We skip this test in multiple unit per file mode since in this -- case we can have multiple units from the same source file. if Unum > Units.Last and then Get_Unit_Index (Uname_Actual) = 0 then for J in Units.First .. Units.Last loop if Fname = Units.Table (J).Unit_File_Name then if Debug_Flag_L then Write_Str (" file does not contain unit, Unit_Number = "); Write_Int (Int (Unum)); Write_Eol; Write_Eol; end if; if Present (Error_Node) then if Is_Predefined_File_Name (Fname) then Error_Msg_Name_1 := Uname_Actual; Error_Msg ("% is not a language defined unit", Load_Msg_Sloc); else Error_Msg_Name_1 := Fname; Error_Msg_Unit_1 := Uname_Actual; Error_Msg ("File{ does not contain unit$", Load_Msg_Sloc); end if; Write_Dependency_Chain; return No_Unit; else return No_Unit; end if; end if; end loop; end if; -- If we are proceeding with load, then make load stack entry, -- and indicate the kind of with_clause responsible for the load. Load_Stack.Increment_Last; Load_Stack.Table (Load_Stack.Last) := (Unum, From_Limited_With); -- Case of entry already in table if Unum <= Units.Last then -- Here is where we check for a circular dependency, which is -- an attempt to load a unit which is currently in the process -- of being loaded. We do *not* care about a circular chain that -- leads back to a body, because this kind of circular dependence -- legitimately occurs (e.g. two package bodies that contain -- inlined subprogram referenced by the other). -- Ada 2005 (AI-50217): We also ignore limited_with clauses, because -- their purpose is precisely to create legal circular structures. if Loading (Unum) and then (Is_Spec_Name (Units.Table (Unum).Unit_Name) or else Acts_As_Spec (Units.Table (Unum).Cunit)) and then (Nkind (Error_Node) /= N_With_Clause or else not Limited_Present (Error_Node)) and then not From_Limited_With_Chain (From_Limited_With) then if Debug_Flag_L then Write_Str (" circular dependency encountered"); Write_Eol; end if; if Present (Error_Node) then Error_Msg ("circular unit dependency", Load_Msg_Sloc); Write_Dependency_Chain; else Load_Stack.Decrement_Last; end if; return No_Unit; end if; if Debug_Flag_L then Write_Str (" unit already in file table, Unit_Number = "); Write_Int (Int (Unum)); Write_Eol; end if; Load_Stack.Decrement_Last; return Unum; -- Unit is not already in table, so try to open the file else if Debug_Flag_L then Write_Str (" attempt unit load, Unit_Number = "); Write_Int (Int (Unum)); Write_Eol; end if; Src_Ind := Load_Source_File (Fname); -- Make a partial entry in the file table, used even in the file not -- found case to print the dependency chain including the last entry Units.Increment_Last; Units.Table (Unum).Unit_Name := Uname_Actual; -- File was found if Src_Ind /= No_Source_File then Units.Table (Unum) := ( Cunit => Empty, Cunit_Entity => Empty, Dependency_Num => 0, Dynamic_Elab => False, Error_Location => Sloc (Error_Node), Expected_Unit => Uname_Actual, Fatal_Error => False, Generate_Code => False, Has_RACW => False, Ident_String => Empty, Loading => True, Main_Priority => Default_Main_Priority, Munit_Index => 0, Serial_Number => 0, Source_Index => Src_Ind, Unit_File_Name => Fname, Unit_Name => Uname_Actual, Version => Source_Checksum (Src_Ind)); -- Parse the new unit declare Save_Index : constant Nat := Multiple_Unit_Index; begin Multiple_Unit_Index := Get_Unit_Index (Uname_Actual); Units.Table (Unum).Munit_Index := Multiple_Unit_Index; Initialize_Scanner (Unum, Source_Index (Unum)); Discard_List (Par (Configuration_Pragmas => False, From_Limited_With => From_Limited_With)); Multiple_Unit_Index := Save_Index; Set_Loading (Unum, False); end; -- If spec is irrelevant, then post errors and quit if Corr_Body /= No_Unit and then Spec_Is_Irrelevant (Unum, Corr_Body) then Error_Msg_Name_1 := Unit_File_Name (Corr_Body); Error_Msg ("cannot compile subprogram in file {!", Load_Msg_Sloc); Error_Msg_Name_1 := Unit_File_Name (Unum); Error_Msg ("\incorrect spec in file { must be removed first!", Load_Msg_Sloc); return No_Unit; end if; -- If loaded unit had a fatal error, then caller inherits it! if Units.Table (Unum).Fatal_Error and then Present (Error_Node) then Units.Table (Calling_Unit).Fatal_Error := True; end if; -- Remove load stack entry and return the entry in the file table Load_Stack.Decrement_Last; return Unum; -- Case of file not found else if Debug_Flag_L then Write_Str (" file was not found, load failed"); Write_Eol; end if; -- Generate message if unit required if Required and then Present (Error_Node) then if Is_Predefined_File_Name (Fname) then -- This is a predefined library unit which is not present -- in the run time. If a predefined unit is not available -- it may very likely be the case that there is also pragma -- Restriction forbidding its usage. This is typically the -- case when building a configurable run time, where the -- usage of certain run-time units units is restricted by -- means of both the corresponding pragma Restriction (such -- as No_Calendar), and by not including the unit. Hence, -- we check whether this predefined unit is forbidden, so -- that the message about the restriction violation is -- generated, if needed. Check_Restricted_Unit (Load_Name, Error_Node); Error_Msg_Name_1 := Uname_Actual; Error_Msg ("% is not a predefined library unit", Load_Msg_Sloc); else Error_Msg_Name_1 := Fname; Error_Msg ("file{ not found", Load_Msg_Sloc); end if; Write_Dependency_Chain; -- Remove unit from stack, to avoid cascaded errors on -- subsequent missing files. Load_Stack.Decrement_Last; Units.Decrement_Last; -- If unit not required, remove load stack entry and the junk -- file table entry, and return No_Unit to indicate not found, else Load_Stack.Decrement_Last; Units.Decrement_Last; end if; return No_Unit; end if; end if; end Load_Unit; ------------------------ -- Make_Instance_Unit -- ------------------------ -- If the unit is an instance, it appears as a package declaration, but -- contains both declaration and body of the instance. The body becomes -- the main unit of the compilation, and the declaration is inserted -- at the end of the unit table. The main unit now has the name of a -- body, which is constructed from the name of the original spec, -- and is attached to the compilation node of the original unit. The -- declaration has been attached to a new compilation unit node, and -- code will have to be generated for it. procedure Make_Instance_Unit (N : Node_Id) is Sind : constant Source_File_Index := Source_Index (Main_Unit); begin Units.Increment_Last; Units.Table (Units.Last) := Units.Table (Main_Unit); Units.Table (Units.Last).Cunit := Library_Unit (N); Units.Table (Units.Last).Generate_Code := True; Units.Table (Main_Unit).Cunit := N; Units.Table (Main_Unit).Unit_Name := Get_Body_Name (Unit_Name (Get_Cunit_Unit_Number (Library_Unit (N)))); Units.Table (Main_Unit).Version := Source_Checksum (Sind); end Make_Instance_Unit; ------------------------ -- Spec_Is_Irrelevant -- ------------------------ function Spec_Is_Irrelevant (Spec_Unit : Unit_Number_Type; Body_Unit : Unit_Number_Type) return Boolean is Sunit : constant Node_Id := Cunit (Spec_Unit); Bunit : constant Node_Id := Cunit (Body_Unit); begin -- The spec is irrelevant if the body is a subprogram body, and the -- spec is other than a subprogram spec or generic subprogram spec. -- Note that the names must be the same, we don't need to check that, -- because we already know that from the fact that the file names are -- the same. return Nkind (Unit (Bunit)) = N_Subprogram_Body and then Nkind (Unit (Sunit)) /= N_Subprogram_Declaration and then Nkind (Unit (Sunit)) /= N_Generic_Subprogram_Declaration; end Spec_Is_Irrelevant; -------------------- -- Version_Update -- -------------------- procedure Version_Update (U : Node_Id; From : Node_Id) is Unum : constant Unit_Number_Type := Get_Cunit_Unit_Number (U); Fnum : constant Unit_Number_Type := Get_Cunit_Unit_Number (From); begin if Source_Index (Fnum) /= No_Source_File then Units.Table (Unum).Version := Units.Table (Unum).Version xor Source_Checksum (Source_Index (Fnum)); end if; end Version_Update; ---------------------------- -- Write_Dependency_Chain -- ---------------------------- procedure Write_Dependency_Chain is begin -- The dependency chain is only written if it is at least two entries -- deep, otherwise it is trivial (the main unit depending on a unit -- that it obviously directly depends on). if Load_Stack.Last - 1 > Load_Stack.First then for U in Load_Stack.First .. Load_Stack.Last - 1 loop Error_Msg_Unit_1 := Unit_Name (Load_Stack.Table (U).Unit_Number); Error_Msg_Unit_2 := Unit_Name (Load_Stack.Table (U + 1).Unit_Number); Error_Msg ("$ depends on $!", Load_Msg_Sloc); end loop; end if; end Write_Dependency_Chain; end Lib.Load;