------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 1 0 -- -- -- -- B o d y -- -- -- -- -- -- 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. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Errout; use Errout; with Exp_Util; use Exp_Util; with Fname; use Fname; with Fname.UF; use Fname.UF; with Freeze; use Freeze; with Impunit; use Impunit; with Inline; use Inline; with Lib; use Lib; with Lib.Load; use Lib.Load; with Lib.Xref; use Lib.Xref; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Sem; use Sem; with Sem_Ch6; use Sem_Ch6; with Sem_Ch7; use Sem_Ch7; with Sem_Ch8; use Sem_Ch8; with Sem_Dist; use Sem_Dist; with Sem_Prag; use Sem_Prag; with Sem_Util; use Sem_Util; with Sem_Warn; use Sem_Warn; with Stand; use Stand; with Sinfo; use Sinfo; with Sinfo.CN; use Sinfo.CN; with Sinput; use Sinput; with Snames; use Snames; with Style; use Style; with Tbuild; use Tbuild; with Ttypes; use Ttypes; with Uname; use Uname; package body Sem_Ch10 is ----------------------- -- Local Subprograms -- ----------------------- procedure Analyze_Context (N : Node_Id); -- Analyzes items in the context clause of compilation unit procedure Check_With_Type_Clauses (N : Node_Id); -- If N is a body, verify that any with_type clauses on the spec, or -- on the spec of any parent, have a matching with_clause. procedure Check_Private_Child_Unit (N : Node_Id); -- If a with_clause mentions a private child unit, the compilation -- unit must be a member of the same family, as described in 10.1.2 (8). procedure Check_Stub_Level (N : Node_Id); -- Verify that a stub is declared immediately within a compilation unit, -- and not in an inner frame. procedure Expand_With_Clause (Nam : Node_Id; N : Node_Id); -- When a child unit appears in a context clause, the implicit withs on -- parents are made explicit, and with clauses are inserted in the context -- clause before the one for the child. If a parent in the with_clause -- is a renaming, the implicit with_clause is on the renaming whose name -- is mentioned in the with_clause, and not on the package it renames. -- N is the compilation unit whose list of context items receives the -- implicit with_clauses. function Get_Parent_Entity (Unit : Node_Id) return Entity_Id; -- Get defining entity of parent unit of a child unit. In most cases this -- is the defining entity of the unit, but for a child instance whose -- parent needs a body for inlining, the instantiation node of the parent -- has not yet been rewritten as a package declaration, and the entity has -- to be retrieved from the Instance_Spec of the unit. procedure Implicit_With_On_Parent (Child_Unit : Node_Id; N : Node_Id); -- If the main unit is a child unit, implicit withs are also added for -- all its ancestors. procedure Install_Context_Clauses (N : Node_Id); -- Subsidiary to previous one. Process only with_ and use_clauses for -- current unit and its library unit if any. procedure Install_Withed_Unit (With_Clause : Node_Id); -- If the unit is not a child unit, make unit immediately visible. -- The caller ensures that the unit is not already currently installed. procedure Install_Parents (Lib_Unit : Node_Id; Is_Private : Boolean); -- This procedure establishes the context for the compilation of a child -- unit. If Lib_Unit is a child library spec then the context of the parent -- is installed, and the parent itself made immediately visible, so that -- the child unit is processed in the declarative region of the parent. -- Install_Parents makes a recursive call to itself to ensure that all -- parents are loaded in the nested case. If Lib_Unit is a library body, -- the only effect of Install_Parents is to install the private decls of -- the parents, because the visible parent declarations will have been -- installed as part of the context of the corresponding spec. procedure Install_Siblings (U_Name : Entity_Id; N : Node_Id); -- In the compilation of a child unit, a child of any of the ancestor -- units is directly visible if it is visible, because the parent is in -- an enclosing scope. Iterate over context to find child units of U_Name -- or of some ancestor of it. function Is_Child_Spec (Lib_Unit : Node_Id) return Boolean; -- Lib_Unit is a library unit which may be a spec or a body. Is_Child_Spec -- returns True if Lib_Unit is a library spec which is a child spec, i.e. -- a library spec that has a parent. If the call to Is_Child_Spec returns -- True, then Parent_Spec (Lib_Unit) is non-Empty and points to the -- compilation unit for the parent spec. -- -- Lib_Unit can also be a subprogram body that acts as its own spec. If -- the Parent_Spec is non-empty, this is also a child unit. procedure Remove_With_Type_Clause (Name : Node_Id); -- Remove imported type and its enclosing package from visibility, and -- remove attributes of imported type so they don't interfere with its -- analysis (should it appear otherwise in the context). procedure Remove_Context_Clauses (N : Node_Id); -- Subsidiary of previous one. Remove use_ and with_clauses. procedure Remove_Parents (Lib_Unit : Node_Id); -- Remove_Parents checks if Lib_Unit is a child spec. If so then the parent -- contexts established by the corresponding call to Install_Parents are -- removed. Remove_Parents contains a recursive call to itself to ensure -- that all parents are removed in the nested case. procedure Remove_Unit_From_Visibility (Unit_Name : Entity_Id); -- Reset all visibility flags on unit after compiling it, either as a -- main unit or as a unit in the context. procedure Analyze_Proper_Body (N : Node_Id; Nam : Entity_Id); -- Common processing for all stubs (subprograms, tasks, packages, and -- protected cases). N is the stub to be analyzed. Once the subunit -- name is established, load and analyze. Nam is the non-overloadable -- entity for which the proper body provides a completion. Subprogram -- stubs are handled differently because they can be declarations. ------------------------------ -- Analyze_Compilation_Unit -- ------------------------------ procedure Analyze_Compilation_Unit (N : Node_Id) is Unit_Node : constant Node_Id := Unit (N); Lib_Unit : Node_Id := Library_Unit (N); Spec_Id : Node_Id; Main_Cunit : constant Node_Id := Cunit (Main_Unit); Par_Spec_Name : Unit_Name_Type; Unum : Unit_Number_Type; procedure Generate_Parent_References (N : Node_Id; P_Id : Entity_Id); -- Generate cross-reference information for the parents of child units. -- N is a defining_program_unit_name, and P_Id is the immediate parent. -------------------------------- -- Generate_Parent_References -- -------------------------------- procedure Generate_Parent_References (N : Node_Id; P_Id : Entity_Id) is Pref : Node_Id; P_Name : Entity_Id := P_Id; begin Pref := Name (Parent (Defining_Entity (N))); if Nkind (Pref) = N_Expanded_Name then -- Done already, if the unit has been compiled indirectly as -- part of the closure of its context because of inlining. return; end if; while Nkind (Pref) = N_Selected_Component loop Change_Selected_Component_To_Expanded_Name (Pref); Set_Entity (Pref, P_Name); Set_Etype (Pref, Etype (P_Name)); Generate_Reference (P_Name, Pref, 'r'); Pref := Prefix (Pref); P_Name := Scope (P_Name); end loop; -- The guard here on P_Name is to handle the error condition where -- the parent unit is missing because the file was not found. if Present (P_Name) then Set_Entity (Pref, P_Name); Set_Etype (Pref, Etype (P_Name)); Generate_Reference (P_Name, Pref, 'r'); Style.Check_Identifier (Pref, P_Name); end if; end Generate_Parent_References; -- Start of processing for Analyze_Compilation_Unit begin Process_Compilation_Unit_Pragmas (N); -- If the unit is a subunit whose parent has not been analyzed (which -- indicates that the main unit is a subunit, either the current one or -- one of its descendents) then the subunit is compiled as part of the -- analysis of the parent, which we proceed to do. Basically this gets -- handled from the top down and we don't want to do anything at this -- level (i.e. this subunit will be handled on the way down from the -- parent), so at this level we immediately return. If the subunit -- ends up not analyzed, it means that the parent did not contain a -- stub for it, or that there errors were dectected in some ancestor. if Nkind (Unit_Node) = N_Subunit and then not Analyzed (Lib_Unit) then Semantics (Lib_Unit); if not Analyzed (Proper_Body (Unit_Node)) then if Serious_Errors_Detected > 0 then Error_Msg_N ("subunit not analyzed (errors in parent unit)", N); else Error_Msg_N ("missing stub for subunit", N); end if; end if; return; end if; -- Analyze context (this will call Sem recursively for with'ed units) Analyze_Context (N); -- If the unit is a package body, the spec is already loaded and must -- be analyzed first, before we analyze the body. if Nkind (Unit_Node) = N_Package_Body then -- If no Lib_Unit, then there was a serious previous error, so -- just ignore the entire analysis effort if No (Lib_Unit) then return; else Semantics (Lib_Unit); Check_Unused_Withs (Get_Cunit_Unit_Number (Lib_Unit)); -- Verify that the library unit is a package declaration. if Nkind (Unit (Lib_Unit)) /= N_Package_Declaration and then Nkind (Unit (Lib_Unit)) /= N_Generic_Package_Declaration then Error_Msg_N ("no legal package declaration for package body", N); return; -- Otherwise, the entity in the declaration is visible. Update -- the version to reflect dependence of this body on the spec. else Spec_Id := Defining_Entity (Unit (Lib_Unit)); Set_Is_Immediately_Visible (Spec_Id, True); Version_Update (N, Lib_Unit); if Nkind (Defining_Unit_Name (Unit_Node)) = N_Defining_Program_Unit_Name then Generate_Parent_References (Unit_Node, Scope (Spec_Id)); end if; end if; end if; -- If the unit is a subprogram body, then we similarly need to analyze -- its spec. However, things are a little simpler in this case, because -- here, this analysis is done only for error checking and consistency -- purposes, so there's nothing else to be done. elsif Nkind (Unit_Node) = N_Subprogram_Body then if Acts_As_Spec (N) then -- If the subprogram body is a child unit, we must create a -- declaration for it, in order to properly load the parent(s). -- After this, the original unit does not acts as a spec, because -- there is an explicit one. If this unit appears in a context -- clause, then an implicit with on the parent will be added when -- installing the context. If this is the main unit, there is no -- Unit_Table entry for the declaration, (It has the unit number -- of the main unit) and code generation is unaffected. Unum := Get_Cunit_Unit_Number (N); Par_Spec_Name := Get_Parent_Spec_Name (Unit_Name (Unum)); if Par_Spec_Name /= No_Name then Unum := Load_Unit (Load_Name => Par_Spec_Name, Required => True, Subunit => False, Error_Node => N); if Unum /= No_Unit then -- Build subprogram declaration and attach parent unit to it -- This subprogram declaration does not come from source! declare Loc : constant Source_Ptr := Sloc (N); SCS : constant Boolean := Get_Comes_From_Source_Default; begin Set_Comes_From_Source_Default (False); Lib_Unit := Make_Compilation_Unit (Loc, Context_Items => New_Copy_List (Context_Items (N)), Unit => Make_Subprogram_Declaration (Sloc (N), Specification => Copy_Separate_Tree (Specification (Unit_Node))), Aux_Decls_Node => Make_Compilation_Unit_Aux (Loc)); Set_Library_Unit (N, Lib_Unit); Set_Parent_Spec (Unit (Lib_Unit), Cunit (Unum)); Semantics (Lib_Unit); Set_Acts_As_Spec (N, False); Set_Comes_From_Source_Default (SCS); end; end if; end if; -- Here for subprogram with separate declaration else Semantics (Lib_Unit); Check_Unused_Withs (Get_Cunit_Unit_Number (Lib_Unit)); Version_Update (N, Lib_Unit); end if; if Nkind (Defining_Unit_Name (Specification (Unit_Node))) = N_Defining_Program_Unit_Name then Generate_Parent_References ( Specification (Unit_Node), Scope (Defining_Entity (Unit (Lib_Unit)))); end if; end if; -- If it is a child unit, the parent must be elaborated first -- and we update version, since we are dependent on our parent. if Is_Child_Spec (Unit_Node) then -- The analysis of the parent is done with style checks off declare Save_Style_Check : constant Boolean := Opt.Style_Check; Save_C_Restrict : constant Save_Compilation_Unit_Restrictions := Compilation_Unit_Restrictions_Save; begin if not GNAT_Mode then Style_Check := False; end if; Semantics (Parent_Spec (Unit_Node)); Version_Update (N, Parent_Spec (Unit_Node)); Style_Check := Save_Style_Check; Compilation_Unit_Restrictions_Restore (Save_C_Restrict); end; end if; -- With the analysis done, install the context. Note that we can't -- install the context from the with clauses as we analyze them, -- because each with clause must be analyzed in a clean visibility -- context, so we have to wait and install them all at once. Install_Context (N); if Is_Child_Spec (Unit_Node) then -- Set the entities of all parents in the program_unit_name. Generate_Parent_References ( Unit_Node, Get_Parent_Entity (Unit (Parent_Spec (Unit_Node)))); end if; -- All components of the context: with-clauses, library unit, ancestors -- if any, (and their context) are analyzed and installed. Now analyze -- the unit itself, which is either a package, subprogram spec or body. Analyze (Unit_Node); -- The above call might have made Unit_Node an N_Subprogram_Body -- from something else, so propagate any Acts_As_Spec flag. if Nkind (Unit_Node) = N_Subprogram_Body and then Acts_As_Spec (Unit_Node) then Set_Acts_As_Spec (N); end if; -- Treat compilation unit pragmas that appear after the library unit if Present (Pragmas_After (Aux_Decls_Node (N))) then declare Prag_Node : Node_Id := First (Pragmas_After (Aux_Decls_Node (N))); begin while Present (Prag_Node) loop Analyze (Prag_Node); Next (Prag_Node); end loop; end; end if; -- Generate distribution stub files if requested and no error if N = Main_Cunit and then (Distribution_Stub_Mode = Generate_Receiver_Stub_Body or else Distribution_Stub_Mode = Generate_Caller_Stub_Body) and then not Fatal_Error (Main_Unit) then if Is_RCI_Pkg_Spec_Or_Body (N) then -- Regular RCI package Add_Stub_Constructs (N); elsif (Nkind (Unit_Node) = N_Package_Declaration and then Is_Shared_Passive (Defining_Entity (Specification (Unit_Node)))) or else (Nkind (Unit_Node) = N_Package_Body and then Is_Shared_Passive (Corresponding_Spec (Unit_Node))) then -- Shared passive package Add_Stub_Constructs (N); elsif Nkind (Unit_Node) = N_Package_Instantiation and then Is_Remote_Call_Interface (Defining_Entity (Specification (Instance_Spec (Unit_Node)))) then -- Instantiation of a RCI generic package Add_Stub_Constructs (N); end if; -- Reanalyze the unit with the new constructs Analyze (Unit_Node); end if; if Nkind (Unit_Node) = N_Package_Declaration or else Nkind (Unit_Node) in N_Generic_Declaration or else Nkind (Unit_Node) = N_Package_Renaming_Declaration or else Nkind (Unit_Node) = N_Subprogram_Declaration then Remove_Unit_From_Visibility (Defining_Entity (Unit_Node)); elsif Nkind (Unit_Node) = N_Package_Body or else (Nkind (Unit_Node) = N_Subprogram_Body and then not Acts_As_Spec (Unit_Node)) then -- Bodies that are not the main unit are compiled if they -- are generic or contain generic or inlined units. Their -- analysis brings in the context of the corresponding spec -- (unit declaration) which must be removed as well, to -- return the compilation environment to its proper state. Remove_Context (Lib_Unit); Set_Is_Immediately_Visible (Defining_Entity (Unit (Lib_Unit)), False); end if; -- Last step is to deinstall the context we just installed -- as well as the unit just compiled. Remove_Context (N); -- If this is the main unit and we are generating code, we must -- check that all generic units in the context have a body if they -- need it, even if they have not been instantiated. In the absence -- of .ali files for generic units, we must force the load of the body, -- just to produce the proper error if the body is absent. We skip this -- verification if the main unit itself is generic. if Get_Cunit_Unit_Number (N) = Main_Unit and then Operating_Mode = Generate_Code and then Expander_Active then -- Indicate that the main unit is now analyzed, to catch possible -- circularities between it and generic bodies. Remove main unit -- from visibility. This might seem superfluous, but the main unit -- must not be visible in the generic body expansions that follow. Set_Analyzed (N, True); Set_Is_Immediately_Visible (Cunit_Entity (Main_Unit), False); declare Item : Node_Id; Nam : Entity_Id; Un : Unit_Number_Type; Save_Style_Check : constant Boolean := Opt.Style_Check; Save_C_Restrict : constant Save_Compilation_Unit_Restrictions := Compilation_Unit_Restrictions_Save; begin Item := First (Context_Items (N)); while Present (Item) loop if Nkind (Item) = N_With_Clause and then not Implicit_With (Item) then Nam := Entity (Name (Item)); if (Ekind (Nam) = E_Generic_Procedure and then not Is_Intrinsic_Subprogram (Nam)) or else (Ekind (Nam) = E_Generic_Function and then not Is_Intrinsic_Subprogram (Nam)) or else (Ekind (Nam) = E_Generic_Package and then Unit_Requires_Body (Nam)) then Opt.Style_Check := False; if Present (Renamed_Object (Nam)) then Un := Load_Unit (Load_Name => Get_Body_Name (Get_Unit_Name (Unit_Declaration_Node (Renamed_Object (Nam)))), Required => False, Subunit => False, Error_Node => N, Renamings => True); else Un := Load_Unit (Load_Name => Get_Body_Name (Get_Unit_Name (Item)), Required => False, Subunit => False, Error_Node => N, Renamings => True); end if; if Un = No_Unit then Error_Msg_NE ("body of generic unit& not found", Item, Nam); exit; elsif not Analyzed (Cunit (Un)) and then Un /= Main_Unit then Opt.Style_Check := False; Semantics (Cunit (Un)); end if; end if; end if; Next (Item); end loop; Style_Check := Save_Style_Check; Compilation_Unit_Restrictions_Restore (Save_C_Restrict); end; end if; -- Deal with creating elaboration Boolean if needed. We create an -- elaboration boolean only for units that come from source since -- units manufactured by the compiler never need elab checks. if Comes_From_Source (N) and then (Nkind (Unit (N)) = N_Package_Declaration or else Nkind (Unit (N)) = N_Generic_Package_Declaration or else Nkind (Unit (N)) = N_Subprogram_Declaration or else Nkind (Unit (N)) = N_Generic_Subprogram_Declaration) then declare Loc : constant Source_Ptr := Sloc (N); Unum : constant Unit_Number_Type := Get_Source_Unit (Loc); begin Spec_Id := Defining_Entity (Unit (N)); Generate_Definition (Spec_Id); -- See if an elaboration entity is required for possible -- access before elaboration checking. Note that we must -- allow for this even if -gnatE is not set, since a client -- may be compiled in -gnatE mode and reference the entity. -- Case of units which do not require elaboration checks if -- Pure units do not need checks Is_Pure (Spec_Id) -- Preelaborated units do not need checks or else Is_Preelaborated (Spec_Id) -- No checks needed if pagma Elaborate_Body present or else Has_Pragma_Elaborate_Body (Spec_Id) -- No checks needed if unit does not require a body or else not Unit_Requires_Body (Spec_Id) -- No checks needed for predefined files or else Is_Predefined_File_Name (Unit_File_Name (Unum)) -- No checks required if no separate spec or else Acts_As_Spec (N) then -- This is a case where we only need the entity for -- checking to prevent multiple elaboration checks. Set_Elaboration_Entity_Required (Spec_Id, False); -- Case of elaboration entity is required for access before -- elaboration checking (so certainly we must build it!) else Set_Elaboration_Entity_Required (Spec_Id, True); end if; Build_Elaboration_Entity (N, Spec_Id); end; end if; -- Finally, freeze the compilation unit entity. This for sure is needed -- because of some warnings that can be output (see Freeze_Subprogram), -- but may in general be required. If freezing actions result, place -- them in the compilation unit actions list, and analyze them. declare Loc : constant Source_Ptr := Sloc (N); L : constant List_Id := Freeze_Entity (Cunit_Entity (Current_Sem_Unit), Loc); begin while Is_Non_Empty_List (L) loop Insert_Library_Level_Action (Remove_Head (L)); end loop; end; Set_Analyzed (N); if Nkind (Unit_Node) = N_Package_Declaration and then Get_Cunit_Unit_Number (N) /= Main_Unit and then Front_End_Inlining and then Expander_Active then Check_Body_For_Inlining (N, Defining_Entity (Unit_Node)); end if; end Analyze_Compilation_Unit; --------------------- -- Analyze_Context -- --------------------- procedure Analyze_Context (N : Node_Id) is Item : Node_Id; begin -- Loop through context items Item := First (Context_Items (N)); while Present (Item) loop -- For with clause, analyze the with clause, and then update -- the version, since we are dependent on a unit that we with. if Nkind (Item) = N_With_Clause then -- Skip analyzing with clause if no unit, nothing to do (this -- happens for a with that references a non-existent unit) if Present (Library_Unit (Item)) then Analyze (Item); end if; if not Implicit_With (Item) then Version_Update (N, Library_Unit (Item)); end if; -- But skip use clauses at this stage, since we don't want to do -- any installing of potentially use visible entities until we -- we actually install the complete context (in Install_Context). -- Otherwise things can get installed in the wrong context. -- Similarly, pragmas are analyzed in Install_Context, after all -- the implicit with's on parent units are generated. else null; end if; Next (Item); end loop; end Analyze_Context; ------------------------------- -- Analyze_Package_Body_Stub -- ------------------------------- procedure Analyze_Package_Body_Stub (N : Node_Id) is Id : constant Entity_Id := Defining_Identifier (N); Nam : Entity_Id; begin -- The package declaration must be in the current declarative part. Check_Stub_Level (N); Nam := Current_Entity_In_Scope (Id); if No (Nam) or else not Is_Package (Nam) then Error_Msg_N ("missing specification for package stub", N); elsif Has_Completion (Nam) and then Present (Corresponding_Body (Unit_Declaration_Node (Nam))) then Error_Msg_N ("duplicate or redundant stub for package", N); else -- Indicate that the body of the package exists. If we are doing -- only semantic analysis, the stub stands for the body. If we are -- generating code, the existence of the body will be confirmed -- when we load the proper body. Set_Has_Completion (Nam); Set_Scope (Defining_Entity (N), Current_Scope); Analyze_Proper_Body (N, Nam); end if; end Analyze_Package_Body_Stub; ------------------------- -- Analyze_Proper_Body -- ------------------------- procedure Analyze_Proper_Body (N : Node_Id; Nam : Entity_Id) is Subunit_Name : constant Unit_Name_Type := Get_Unit_Name (N); Unum : Unit_Number_Type; Subunit_Not_Found : Boolean := False; procedure Optional_Subunit; -- This procedure is called when the main unit is a stub, or when we -- are not generating code. In such a case, we analyze the subunit if -- present, which is user-friendly and in fact required for ASIS, but -- we don't complain if the subunit is missing. ---------------------- -- Optional_Subunit -- ---------------------- procedure Optional_Subunit is Comp_Unit : Node_Id; begin -- Try to load subunit, but ignore any errors that occur during -- the loading of the subunit, by using the special feature in -- Errout to ignore all errors. Note that Fatal_Error will still -- be set, so we will be able to check for this case below. Ignore_Errors_Enable := Ignore_Errors_Enable + 1; Unum := Load_Unit (Load_Name => Subunit_Name, Required => False, Subunit => True, Error_Node => N); Ignore_Errors_Enable := Ignore_Errors_Enable - 1; -- All done if we successfully loaded the subunit if Unum /= No_Unit and then not Fatal_Error (Unum) then Comp_Unit := Cunit (Unum); Set_Corresponding_Stub (Unit (Comp_Unit), N); Analyze_Subunit (Comp_Unit); Set_Library_Unit (N, Comp_Unit); elsif Unum = No_Unit and then Present (Nam) then if Is_Protected_Type (Nam) then Set_Corresponding_Body (Parent (Nam), Defining_Identifier (N)); else Set_Corresponding_Body ( Unit_Declaration_Node (Nam), Defining_Identifier (N)); end if; end if; end Optional_Subunit; -- Start of processing for Analyze_Proper_Body begin -- If the subunit is already loaded, it means that the main unit -- is a subunit, and that the current unit is one of its parents -- which was being analyzed to provide the needed context for the -- analysis of the subunit. In this case we analyze the subunit and -- continue with the parent, without looking a subsequent subunits. if Is_Loaded (Subunit_Name) then -- If the proper body is already linked to the stub node, -- the stub is in a generic unit and just needs analyzing. if Present (Library_Unit (N)) then Set_Corresponding_Stub (Unit (Library_Unit (N)), N); Analyze_Subunit (Library_Unit (N)); -- Otherwise we must load the subunit and link to it else -- Load the subunit, this must work, since we originally -- loaded the subunit earlier on. So this will not really -- load it, just give access to it. Unum := Load_Unit (Load_Name => Subunit_Name, Required => True, Subunit => False, Error_Node => N); -- And analyze the subunit in the parent context (note that we -- do not call Semantics, since that would remove the parent -- context). Because of this, we have to manually reset the -- compiler state to Analyzing since it got destroyed by Load. if Unum /= No_Unit then Compiler_State := Analyzing; Set_Corresponding_Stub (Unit (Cunit (Unum)), N); Analyze_Subunit (Cunit (Unum)); Set_Library_Unit (N, Cunit (Unum)); end if; end if; -- If the main unit is a subunit, then we are just performing semantic -- analysis on that subunit, and any other subunits of any parent unit -- should be ignored, except that if we are building trees for ASIS -- usage we want to annotate the stub properly. elsif Nkind (Unit (Cunit (Main_Unit))) = N_Subunit and then Subunit_Name /= Unit_Name (Main_Unit) then if Tree_Output then Optional_Subunit; end if; -- But before we return, set the flag for unloaded subunits. This -- will suppress junk warnings of variables in the same declarative -- part (or a higher level one) that are in danger of looking unused -- when in fact there might be a declaration in the subunit that we -- do not intend to load. Unloaded_Subunits := True; return; -- If the subunit is not already loaded, and we are generating code, -- then this is the case where compilation started from the parent, -- and we are generating code for an entire subunit tree. In that -- case we definitely need to load the subunit. -- In order to continue the analysis with the rest of the parent, -- and other subunits, we load the unit without requiring its -- presence, and emit a warning if not found, rather than terminating -- the compilation abruptly, as for other missing file problems. elsif Operating_Mode = Generate_Code then -- If the proper body is already linked to the stub node, -- the stub is in a generic unit and just needs analyzing. -- We update the version. Although we are not technically -- semantically dependent on the subunit, given our approach -- of macro substitution of subunits, it makes sense to -- include it in the version identification. if Present (Library_Unit (N)) then Set_Corresponding_Stub (Unit (Library_Unit (N)), N); Analyze_Subunit (Library_Unit (N)); Version_Update (Cunit (Main_Unit), Library_Unit (N)); -- Otherwise we must load the subunit and link to it else Unum := Load_Unit (Load_Name => Subunit_Name, Required => False, Subunit => True, Error_Node => N); if Operating_Mode = Generate_Code and then Unum = No_Unit then Error_Msg_Name_1 := Subunit_Name; Error_Msg_Name_2 := Get_File_Name (Subunit_Name, Subunit => True); Error_Msg_N ("subunit% in file{ not found!?", N); Subunits_Missing := True; Subunit_Not_Found := True; end if; -- Load_Unit may reset Compiler_State, since it may have been -- necessary to parse an additional units, so we make sure -- that we reset it to the Analyzing state. Compiler_State := Analyzing; if Unum /= No_Unit and then not Fatal_Error (Unum) then if Debug_Flag_L then Write_Str ("*** Loaded subunit from stub. Analyze"); Write_Eol; end if; declare Comp_Unit : constant Node_Id := Cunit (Unum); begin -- Check for child unit instead of subunit if Nkind (Unit (Comp_Unit)) /= N_Subunit then Error_Msg_N ("expected SEPARATE subunit, found child unit", Cunit_Entity (Unum)); -- OK, we have a subunit, so go ahead and analyze it, -- and set Scope of entity in stub, for ASIS use. else Set_Corresponding_Stub (Unit (Comp_Unit), N); Analyze_Subunit (Comp_Unit); Set_Library_Unit (N, Comp_Unit); -- We update the version. Although we are not technically -- semantically dependent on the subunit, given our -- approach of macro substitution of subunits, it makes -- sense to include it in the version identification. Version_Update (Cunit (Main_Unit), Comp_Unit); end if; end; end if; end if; -- The remaining case is when the subunit is not already loaded and -- we are not generating code. In this case we are just performing -- semantic analysis on the parent, and we are not interested in -- the subunit. For subprograms, analyze the stub as a body. For -- other entities the stub has already been marked as completed. else Optional_Subunit; end if; end Analyze_Proper_Body; ---------------------------------- -- Analyze_Protected_Body_Stub -- ---------------------------------- procedure Analyze_Protected_Body_Stub (N : Node_Id) is Nam : Entity_Id := Current_Entity_In_Scope (Defining_Identifier (N)); begin Check_Stub_Level (N); -- First occurrence of name may have been as an incomplete type. if Present (Nam) and then Ekind (Nam) = E_Incomplete_Type then Nam := Full_View (Nam); end if; if No (Nam) or else not Is_Protected_Type (Etype (Nam)) then Error_Msg_N ("missing specification for Protected body", N); else Set_Scope (Defining_Entity (N), Current_Scope); Set_Has_Completion (Etype (Nam)); Analyze_Proper_Body (N, Etype (Nam)); end if; end Analyze_Protected_Body_Stub; ---------------------------------- -- Analyze_Subprogram_Body_Stub -- ---------------------------------- -- A subprogram body stub can appear with or without a previous -- specification. If there is one, the analysis of the body will -- find it and verify conformance. The formals appearing in the -- specification of the stub play no role, except for requiring an -- additional conformance check. If there is no previous subprogram -- declaration, the stub acts as a spec, and provides the defining -- entity for the subprogram. procedure Analyze_Subprogram_Body_Stub (N : Node_Id) is Decl : Node_Id; begin Check_Stub_Level (N); -- Verify that the identifier for the stub is unique within this -- declarative part. if Nkind (Parent (N)) = N_Block_Statement or else Nkind (Parent (N)) = N_Package_Body or else Nkind (Parent (N)) = N_Subprogram_Body then Decl := First (Declarations (Parent (N))); while Present (Decl) and then Decl /= N loop if Nkind (Decl) = N_Subprogram_Body_Stub and then (Chars (Defining_Unit_Name (Specification (Decl))) = Chars (Defining_Unit_Name (Specification (N)))) then Error_Msg_N ("identifier for stub is not unique", N); end if; Next (Decl); end loop; end if; -- Treat stub as a body, which checks conformance if there is a previous -- declaration, or else introduces entity and its signature. Analyze_Subprogram_Body (N); if Serious_Errors_Detected = 0 then Analyze_Proper_Body (N, Empty); end if; end Analyze_Subprogram_Body_Stub; --------------------- -- Analyze_Subunit -- --------------------- -- A subunit is compiled either by itself (for semantic checking) -- or as part of compiling the parent (for code generation). In -- either case, by the time we actually process the subunit, the -- parent has already been installed and analyzed. The node N is -- a compilation unit, whose context needs to be treated here, -- because we come directly here from the parent without calling -- Analyze_Compilation_Unit. -- The compilation context includes the explicit context of the -- subunit, and the context of the parent, together with the parent -- itself. In order to compile the current context, we remove the -- one inherited from the parent, in order to have a clean visibility -- table. We restore the parent context before analyzing the proper -- body itself. On exit, we remove only the explicit context of the -- subunit. procedure Analyze_Subunit (N : Node_Id) is Lib_Unit : constant Node_Id := Library_Unit (N); Par_Unit : constant Entity_Id := Current_Scope; Lib_Spec : Node_Id := Library_Unit (Lib_Unit); Num_Scopes : Int := 0; Use_Clauses : array (1 .. Scope_Stack.Last) of Node_Id; Enclosing_Child : Entity_Id := Empty; procedure Analyze_Subunit_Context; -- Capture names in use clauses of the subunit. This must be done -- before re-installing parent declarations, because items in the -- context must not be hidden by declarations local to the parent. procedure Re_Install_Parents (L : Node_Id; Scop : Entity_Id); -- Recursive procedure to restore scope of all ancestors of subunit, -- from outermost in. If parent is not a subunit, the call to install -- context installs context of spec and (if parent is a child unit) -- the context of its parents as well. It is confusing that parents -- should be treated differently in both cases, but the semantics are -- just not identical. procedure Re_Install_Use_Clauses; -- As part of the removal of the parent scope, the use clauses are -- removed, to be reinstalled when the context of the subunit has -- been analyzed. Use clauses may also have been affected by the -- analysis of the context of the subunit, so they have to be applied -- again, to insure that the compilation environment of the rest of -- the parent unit is identical. procedure Remove_Scope; -- Remove current scope from scope stack, and preserve the list -- of use clauses in it, to be reinstalled after context is analyzed. ------------------------------ -- Analyze_Subunit_Context -- ------------------------------ procedure Analyze_Subunit_Context is Item : Node_Id; Nam : Node_Id; Unit_Name : Entity_Id; begin Analyze_Context (N); Item := First (Context_Items (N)); -- make withed units immediately visible. If child unit, make the -- ultimate parent immediately visible. while Present (Item) loop if Nkind (Item) = N_With_Clause then Unit_Name := Entity (Name (Item)); while Is_Child_Unit (Unit_Name) loop Set_Is_Visible_Child_Unit (Unit_Name); Unit_Name := Scope (Unit_Name); end loop; if not Is_Immediately_Visible (Unit_Name) then Set_Is_Immediately_Visible (Unit_Name); Set_Context_Installed (Item); end if; elsif Nkind (Item) = N_Use_Package_Clause then Nam := First (Names (Item)); while Present (Nam) loop Analyze (Nam); Next (Nam); end loop; elsif Nkind (Item) = N_Use_Type_Clause then Nam := First (Subtype_Marks (Item)); while Present (Nam) loop Analyze (Nam); Next (Nam); end loop; end if; Next (Item); end loop; Item := First (Context_Items (N)); -- reset visibility of withed units. They will be made visible -- again when we install the subunit context. while Present (Item) loop if Nkind (Item) = N_With_Clause then Unit_Name := Entity (Name (Item)); while Is_Child_Unit (Unit_Name) loop Set_Is_Visible_Child_Unit (Unit_Name, False); Unit_Name := Scope (Unit_Name); end loop; if Context_Installed (Item) then Set_Is_Immediately_Visible (Unit_Name, False); Set_Context_Installed (Item, False); end if; end if; Next (Item); end loop; end Analyze_Subunit_Context; ------------------------ -- Re_Install_Parents -- ------------------------ procedure Re_Install_Parents (L : Node_Id; Scop : Entity_Id) is E : Entity_Id; begin if Nkind (Unit (L)) = N_Subunit then Re_Install_Parents (Library_Unit (L), Scope (Scop)); end if; Install_Context (L); -- If the subunit occurs within a child unit, we must restore the -- immediate visibility of any siblings that may occur in context. if Present (Enclosing_Child) then Install_Siblings (Enclosing_Child, L); end if; New_Scope (Scop); if Scop /= Par_Unit then Set_Is_Immediately_Visible (Scop); end if; E := First_Entity (Current_Scope); while Present (E) loop Set_Is_Immediately_Visible (E); Next_Entity (E); end loop; -- A subunit appears within a body, and for a nested subunits -- all the parents are bodies. Restore full visibility of their -- private entities. if Ekind (Scop) = E_Package then Set_In_Package_Body (Scop); Install_Private_Declarations (Scop); end if; end Re_Install_Parents; ---------------------------- -- Re_Install_Use_Clauses -- ---------------------------- procedure Re_Install_Use_Clauses is U : Node_Id; begin for J in reverse 1 .. Num_Scopes loop U := Use_Clauses (J); Scope_Stack.Table (Scope_Stack.Last - J + 1).First_Use_Clause := U; Install_Use_Clauses (U); end loop; end Re_Install_Use_Clauses; ------------------ -- Remove_Scope -- ------------------ procedure Remove_Scope is E : Entity_Id; begin Num_Scopes := Num_Scopes + 1; Use_Clauses (Num_Scopes) := Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause; E := First_Entity (Current_Scope); while Present (E) loop Set_Is_Immediately_Visible (E, False); Next_Entity (E); end loop; if Is_Child_Unit (Current_Scope) then Enclosing_Child := Current_Scope; end if; Pop_Scope; end Remove_Scope; -- Start of processing for Analyze_Subunit begin if not Is_Empty_List (Context_Items (N)) then -- Save current use clauses. Remove_Scope; Remove_Context (Lib_Unit); -- Now remove parents and their context, including enclosing -- subunits and the outer parent body which is not a subunit. if Present (Lib_Spec) then Remove_Context (Lib_Spec); while Nkind (Unit (Lib_Spec)) = N_Subunit loop Lib_Spec := Library_Unit (Lib_Spec); Remove_Scope; Remove_Context (Lib_Spec); end loop; if Nkind (Unit (Lib_Unit)) = N_Subunit then Remove_Scope; end if; if Nkind (Unit (Lib_Spec)) = N_Package_Body then Remove_Context (Library_Unit (Lib_Spec)); end if; end if; Analyze_Subunit_Context; Re_Install_Parents (Lib_Unit, Par_Unit); -- If the context includes a child unit of the parent of the -- subunit, the parent will have been removed from visibility, -- after compiling that cousin in the context. The visibility -- of the parent must be restored now. This also applies if the -- context includes another subunit of the same parent which in -- turn includes a child unit in its context. if Ekind (Par_Unit) = E_Package then if not Is_Immediately_Visible (Par_Unit) or else (Present (First_Entity (Par_Unit)) and then not Is_Immediately_Visible (First_Entity (Par_Unit))) then Set_Is_Immediately_Visible (Par_Unit); Install_Visible_Declarations (Par_Unit); Install_Private_Declarations (Par_Unit); end if; end if; Re_Install_Use_Clauses; Install_Context (N); -- If the subunit is within a child unit, then siblings of any -- parent unit that appear in the context clause of the subunit -- must also be made immediately visible. if Present (Enclosing_Child) then Install_Siblings (Enclosing_Child, N); end if; end if; Analyze (Proper_Body (Unit (N))); Remove_Context (N); end Analyze_Subunit; ---------------------------- -- Analyze_Task_Body_Stub -- ---------------------------- procedure Analyze_Task_Body_Stub (N : Node_Id) is Nam : Entity_Id := Current_Entity_In_Scope (Defining_Identifier (N)); Loc : constant Source_Ptr := Sloc (N); begin Check_Stub_Level (N); -- First occurrence of name may have been as an incomplete type. if Present (Nam) and then Ekind (Nam) = E_Incomplete_Type then Nam := Full_View (Nam); end if; if No (Nam) or else not Is_Task_Type (Etype (Nam)) then Error_Msg_N ("missing specification for task body", N); else Set_Scope (Defining_Entity (N), Current_Scope); Set_Has_Completion (Etype (Nam)); Analyze_Proper_Body (N, Etype (Nam)); -- Set elaboration flag to indicate that entity is callable. -- This cannot be done in the expansion of the body itself, -- because the proper body is not in a declarative part. This -- is only done if expansion is active, because the context -- may be generic and the flag not defined yet. if Expander_Active then Insert_After (N, Make_Assignment_Statement (Loc, Name => Make_Identifier (Loc, New_External_Name (Chars (Etype (Nam)), 'E')), Expression => New_Reference_To (Standard_True, Loc))); end if; end if; end Analyze_Task_Body_Stub; ------------------------- -- Analyze_With_Clause -- ------------------------- -- Analyze the declaration of a unit in a with clause. At end, -- label the with clause with the defining entity for the unit. procedure Analyze_With_Clause (N : Node_Id) is Unit_Kind : constant Node_Kind := Nkind (Unit (Library_Unit (N))); E_Name : Entity_Id; Par_Name : Entity_Id; Pref : Node_Id; U : Node_Id; Intunit : Boolean; -- Set True if the unit currently being compiled is an internal unit Save_Style_Check : constant Boolean := Opt.Style_Check; Save_C_Restrict : constant Save_Compilation_Unit_Restrictions := Compilation_Unit_Restrictions_Save; begin -- We reset ordinary style checking during the analysis of a with'ed -- unit, but we do NOT reset GNAT special analysis mode (the latter -- definitely *does* apply to with'ed units). if not GNAT_Mode then Style_Check := False; end if; -- If the library unit is a predefined unit, and we are in no -- run time mode, then temporarily reset No_Run_Time mode for the -- analysis of the with'ed unit. The No_Run_Time pragma does not -- prevent explicit with'ing of run-time units. if No_Run_Time and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Unit (Library_Unit (N))))) then No_Run_Time := False; Semantics (Library_Unit (N)); No_Run_Time := True; else Semantics (Library_Unit (N)); end if; U := Unit (Library_Unit (N)); Intunit := Is_Internal_File_Name (Unit_File_Name (Current_Sem_Unit)); -- Following checks are skipped for dummy packages (those supplied -- for with's where no matching file could be found). Such packages -- are identified by the Sloc value being set to No_Location if Sloc (U) /= No_Location then -- Check restrictions, except that we skip the check if this -- is an internal unit unless we are compiling the internal -- unit as the main unit. We also skip this for dummy packages. if not Intunit or else Current_Sem_Unit = Main_Unit then Check_Restricted_Unit (Unit_Name (Get_Source_Unit (U)), N); end if; -- Check for inappropriate with of internal implementation unit -- if we are currently compiling the main unit and the main unit -- is itself not an internal unit. if Implementation_Unit_Warnings and then Current_Sem_Unit = Main_Unit and then Implementation_Unit (Get_Source_Unit (U)) and then not Intunit then Error_Msg_N ("& is an internal 'G'N'A'T unit?", Name (N)); Error_Msg_N ("\use of this unit is non-portable and version-dependent?", Name (N)); end if; end if; -- Semantic analysis of a generic unit is performed on a copy of -- the original tree. Retrieve the entity on which semantic info -- actually appears. if Unit_Kind in N_Generic_Declaration then E_Name := Defining_Entity (U); -- Note: in the following test, Unit_Kind is the original Nkind, but -- in the case of an instantiation, semantic analysis above will -- have replaced the unit by its instantiated version. If the instance -- body has been generated, the instance now denotes the body entity. -- For visibility purposes we need the entity of its spec. elsif (Unit_Kind = N_Package_Instantiation or else Nkind (Original_Node (Unit (Library_Unit (N)))) = N_Package_Instantiation) and then Nkind (U) = N_Package_Body then E_Name := Corresponding_Spec (U); elsif Unit_Kind = N_Package_Instantiation and then Nkind (U) = N_Package_Instantiation then -- If the instance has not been rewritten as a package declaration, -- then it appeared already in a previous with clause. Retrieve -- the entity from the previous instance. E_Name := Defining_Entity (Specification (Instance_Spec (U))); elsif Unit_Kind = N_Procedure_Instantiation or else Unit_Kind = N_Function_Instantiation then -- Instantiation node is replaced with a package that contains -- renaming declarations and instance itself. The subprogram -- Instance is declared in the visible part of the wrapper package. E_Name := First_Entity (Defining_Entity (U)); while Present (E_Name) loop exit when Is_Subprogram (E_Name) and then Is_Generic_Instance (E_Name); E_Name := Next_Entity (E_Name); end loop; elsif Unit_Kind = N_Package_Renaming_Declaration or else Unit_Kind in N_Generic_Renaming_Declaration then E_Name := Defining_Entity (U); elsif Unit_Kind = N_Subprogram_Body and then Nkind (Name (N)) = N_Selected_Component and then not Acts_As_Spec (Library_Unit (N)) then -- For a child unit that has no spec, one has been created and -- analyzed. The entity required is that of the spec. E_Name := Corresponding_Spec (U); else E_Name := Defining_Entity (U); end if; if Nkind (Name (N)) = N_Selected_Component then -- Child unit in a with clause Change_Selected_Component_To_Expanded_Name (Name (N)); end if; -- Restore style checks and restrictions Style_Check := Save_Style_Check; Compilation_Unit_Restrictions_Restore (Save_C_Restrict); -- Record the reference, but do NOT set the unit as referenced, we -- want to consider the unit as unreferenced if this is the only -- reference that occurs. Set_Entity_With_Style_Check (Name (N), E_Name); Generate_Reference (E_Name, Name (N), Set_Ref => False); if Is_Child_Unit (E_Name) then Pref := Prefix (Name (N)); Par_Name := Scope (E_Name); while Nkind (Pref) = N_Selected_Component loop Change_Selected_Component_To_Expanded_Name (Pref); Set_Entity_With_Style_Check (Pref, Par_Name); Generate_Reference (Par_Name, Pref); Pref := Prefix (Pref); Par_Name := Scope (Par_Name); end loop; if Present (Entity (Pref)) and then not Analyzed (Parent (Parent (Entity (Pref)))) then -- If the entity is set without its unit being compiled, -- the original parent is a renaming, and Par_Name is the -- renamed entity. For visibility purposes, we need the -- original entity, which must be analyzed now, because -- Load_Unit retrieves directly the renamed unit, and the -- renaming declaration itself has not been analyzed. Analyze (Parent (Parent (Entity (Pref)))); pragma Assert (Renamed_Object (Entity (Pref)) = Par_Name); Par_Name := Entity (Pref); end if; Set_Entity_With_Style_Check (Pref, Par_Name); Generate_Reference (Par_Name, Pref); end if; -- If the withed unit is System, and a system extension pragma is -- present, compile the extension now, rather than waiting for -- a visibility check on a specific entity. if Chars (E_Name) = Name_System and then Scope (E_Name) = Standard_Standard and then Present (System_Extend_Pragma_Arg) and then Present_System_Aux (N) then -- If the extension is not present, an error will have been emitted. null; end if; end Analyze_With_Clause; ------------------------------ -- Analyze_With_Type_Clause -- ------------------------------ procedure Analyze_With_Type_Clause (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Nam : Node_Id := Name (N); Pack : Node_Id; Decl : Node_Id; P : Entity_Id; Unum : Unit_Number_Type; Sel : Node_Id; procedure Decorate_Tagged_Type (T : Entity_Id); -- Set basic attributes of type, including its class_wide type. function In_Chain (E : Entity_Id) return Boolean; -- Check that the imported type is not already in the homonym chain, -- for example through a with_type clause in a parent unit. -------------------------- -- Decorate_Tagged_Type -- -------------------------- procedure Decorate_Tagged_Type (T : Entity_Id) is CW : Entity_Id; begin Set_Ekind (T, E_Record_Type); Set_Is_Tagged_Type (T); Set_Etype (T, T); Set_From_With_Type (T); Set_Scope (T, P); if not In_Chain (T) then Set_Homonym (T, Current_Entity (T)); Set_Current_Entity (T); end if; -- Build bogus class_wide type, if not previously done. if No (Class_Wide_Type (T)) then CW := Make_Defining_Identifier (Loc, New_Internal_Name ('S')); Set_Ekind (CW, E_Class_Wide_Type); Set_Etype (CW, T); Set_Scope (CW, P); Set_Is_Tagged_Type (CW); Set_Is_First_Subtype (CW, True); Init_Size_Align (CW); Set_Has_Unknown_Discriminants (CW, True); Set_Class_Wide_Type (CW, CW); Set_Equivalent_Type (CW, Empty); Set_From_With_Type (CW); Set_Class_Wide_Type (T, CW); end if; end Decorate_Tagged_Type; -------------- -- In_Chain -- -------------- function In_Chain (E : Entity_Id) return Boolean is H : Entity_Id := Current_Entity (E); begin while Present (H) loop if H = E then return True; else H := Homonym (H); end if; end loop; return False; end In_Chain; -- Start of processing for Analyze_With_Type_Clause begin if Nkind (Nam) = N_Selected_Component then Pack := New_Copy_Tree (Prefix (Nam)); Sel := Selector_Name (Nam); else Error_Msg_N ("illegal name for imported type", Nam); return; end if; Decl := Make_Package_Declaration (Loc, Specification => (Make_Package_Specification (Loc, Defining_Unit_Name => Pack, Visible_Declarations => New_List, End_Label => Empty))); Unum := Load_Unit (Load_Name => Get_Unit_Name (Decl), Required => True, Subunit => False, Error_Node => Nam); if Unum = No_Unit or else Nkind (Unit (Cunit (Unum))) /= N_Package_Declaration then Error_Msg_N ("imported type must be declared in package", Nam); return; elsif Unum = Current_Sem_Unit then -- If type is defined in unit being analyzed, then the clause -- is redundant. return; else P := Cunit_Entity (Unum); end if; -- Find declaration for imported type, and set its basic attributes -- if it has not been analyzed (which will be the case if there is -- circular dependence). declare Decl : Node_Id; Typ : Entity_Id; begin if not Analyzed (Cunit (Unum)) and then not From_With_Type (P) then Set_Ekind (P, E_Package); Set_Etype (P, Standard_Void_Type); Set_From_With_Type (P); Set_Scope (P, Standard_Standard); Set_Homonym (P, Current_Entity (P)); Set_Current_Entity (P); elsif Analyzed (Cunit (Unum)) and then Is_Child_Unit (P) then -- If the child unit is already in scope, indicate that it is -- visible, and remains so after intervening calls to rtsfind. Set_Is_Visible_Child_Unit (P); end if; if Nkind (Parent (P)) = N_Defining_Program_Unit_Name then -- Make parent packages visible. declare Parent_Comp : Node_Id; Parent_Id : Entity_Id; Child : Entity_Id; begin Child := P; Parent_Comp := Parent_Spec (Unit (Cunit (Unum))); loop Parent_Id := Defining_Entity (Unit (Parent_Comp)); Set_Scope (Child, Parent_Id); -- The type may be imported from a child unit, in which -- case the current compilation appears in the name. Do -- not change its visibility here because it will conflict -- with the subsequent normal processing. if not Analyzed (Unit_Declaration_Node (Parent_Id)) and then Parent_Id /= Cunit_Entity (Current_Sem_Unit) then Set_Ekind (Parent_Id, E_Package); Set_Etype (Parent_Id, Standard_Void_Type); -- The same package may appear is several with_type -- clauses. if not From_With_Type (Parent_Id) then Set_Homonym (Parent_Id, Current_Entity (Parent_Id)); Set_Current_Entity (Parent_Id); Set_From_With_Type (Parent_Id); end if; end if; Set_Is_Immediately_Visible (Parent_Id); Child := Parent_Id; Parent_Comp := Parent_Spec (Unit (Parent_Comp)); exit when No (Parent_Comp); end loop; Set_Scope (Parent_Id, Standard_Standard); end; end if; -- Even if analyzed, the package may not be currently visible. It -- must be while the with_type clause is active. Set_Is_Immediately_Visible (P); Decl := First (Visible_Declarations (Specification (Unit (Cunit (Unum))))); while Present (Decl) loop if Nkind (Decl) = N_Full_Type_Declaration and then Chars (Defining_Identifier (Decl)) = Chars (Sel) then Typ := Defining_Identifier (Decl); if Tagged_Present (N) then -- The declaration must indicate that this is a tagged -- type or a type extension. if (Nkind (Type_Definition (Decl)) = N_Record_Definition and then Tagged_Present (Type_Definition (Decl))) or else (Nkind (Type_Definition (Decl)) = N_Derived_Type_Definition and then Present (Record_Extension_Part (Type_Definition (Decl)))) then null; else Error_Msg_N ("imported type is not a tagged type", Nam); return; end if; if not Analyzed (Decl) then -- Unit is not currently visible. Add basic attributes -- to type and build its class-wide type. Init_Size_Align (Typ); Decorate_Tagged_Type (Typ); end if; else if Nkind (Type_Definition (Decl)) /= N_Access_To_Object_Definition then Error_Msg_N ("imported type is not an access type", Nam); elsif not Analyzed (Decl) then Set_Ekind (Typ, E_Access_Type); Set_Etype (Typ, Typ); Set_Scope (Typ, P); Init_Size (Typ, System_Address_Size); Init_Alignment (Typ); Set_Directly_Designated_Type (Typ, Standard_Integer); Set_From_With_Type (Typ); if not In_Chain (Typ) then Set_Homonym (Typ, Current_Entity (Typ)); Set_Current_Entity (Typ); end if; end if; end if; Set_Entity (Sel, Typ); return; elsif ((Nkind (Decl) = N_Private_Type_Declaration and then Tagged_Present (Decl)) or else (Nkind (Decl) = N_Private_Extension_Declaration)) and then Chars (Defining_Identifier (Decl)) = Chars (Sel) then Typ := Defining_Identifier (Decl); if not Tagged_Present (N) then Error_Msg_N ("type must be declared tagged", N); elsif not Analyzed (Decl) then Decorate_Tagged_Type (Typ); end if; Set_Entity (Sel, Typ); Set_From_With_Type (Typ); return; end if; Decl := Next (Decl); end loop; Error_Msg_NE ("not a visible access or tagged type in&", Nam, P); end; end Analyze_With_Type_Clause; ----------------------------- -- Check_With_Type_Clauses -- ----------------------------- procedure Check_With_Type_Clauses (N : Node_Id) is Lib_Unit : constant Node_Id := Unit (N); procedure Check_Parent_Context (U : Node_Id); -- Examine context items of parent unit to locate with_type clauses. -------------------------- -- Check_Parent_Context -- -------------------------- procedure Check_Parent_Context (U : Node_Id) is Item : Node_Id; begin Item := First (Context_Items (U)); while Present (Item) loop if Nkind (Item) = N_With_Type_Clause and then not Error_Posted (Item) and then From_With_Type (Scope (Entity (Selector_Name (Name (Item))))) then Error_Msg_Sloc := Sloc (Item); Error_Msg_N ("Missing With_Clause for With_Type_Clause#", N); end if; Next (Item); end loop; end Check_Parent_Context; -- Start of processing for Check_With_Type_Clauses begin if Extensions_Allowed and then (Nkind (Lib_Unit) = N_Package_Body or else Nkind (Lib_Unit) = N_Subprogram_Body) then Check_Parent_Context (Library_Unit (N)); if Is_Child_Spec (Unit (Library_Unit (N))) then Check_Parent_Context (Parent_Spec (Unit (Library_Unit (N)))); end if; end if; end Check_With_Type_Clauses; ------------------------------ -- Check_Private_Child_Unit -- ------------------------------ procedure Check_Private_Child_Unit (N : Node_Id) is Lib_Unit : constant Node_Id := Unit (N); Item : Node_Id; Curr_Unit : Entity_Id; Sub_Parent : Node_Id; Priv_Child : Entity_Id; Par_Lib : Entity_Id; Par_Spec : Node_Id; function Is_Private_Library_Unit (Unit : Entity_Id) return Boolean; -- Returns true if and only if the library unit is declared with -- an explicit designation of private. function Is_Private_Library_Unit (Unit : Entity_Id) return Boolean is begin return Private_Present (Parent (Unit_Declaration_Node (Unit))); end Is_Private_Library_Unit; -- Start of processing for Check_Private_Child_Unit begin if Nkind (Lib_Unit) = N_Package_Body or else Nkind (Lib_Unit) = N_Subprogram_Body then Curr_Unit := Defining_Entity (Unit (Library_Unit (N))); Par_Lib := Curr_Unit; elsif Nkind (Lib_Unit) = N_Subunit then -- The parent is itself a body. The parent entity is to be found -- in the corresponding spec. Sub_Parent := Library_Unit (N); Curr_Unit := Defining_Entity (Unit (Library_Unit (Sub_Parent))); -- If the parent itself is a subunit, Curr_Unit is the entity -- of the enclosing body, retrieve the spec entity which is -- the proper ancestor we need for the following tests. if Ekind (Curr_Unit) = E_Package_Body then Curr_Unit := Spec_Entity (Curr_Unit); end if; Par_Lib := Curr_Unit; else Curr_Unit := Defining_Entity (Lib_Unit); Par_Lib := Curr_Unit; Par_Spec := Parent_Spec (Lib_Unit); if No (Par_Spec) then Par_Lib := Empty; else Par_Lib := Defining_Entity (Unit (Par_Spec)); end if; end if; -- Loop through context items Item := First (Context_Items (N)); while Present (Item) loop if Nkind (Item) = N_With_Clause and then not Implicit_With (Item) and then Is_Private_Descendant (Entity (Name (Item))) then Priv_Child := Entity (Name (Item)); declare Curr_Parent : Entity_Id := Par_Lib; Child_Parent : Entity_Id := Scope (Priv_Child); Prv_Ancestor : Entity_Id := Child_Parent; Curr_Private : Boolean := Is_Private_Library_Unit (Curr_Unit); begin -- If the child unit is a public child then locate -- the nearest private ancestor; Child_Parent will -- then be set to the parent of that ancestor. if not Is_Private_Library_Unit (Priv_Child) then while Present (Prv_Ancestor) and then not Is_Private_Library_Unit (Prv_Ancestor) loop Prv_Ancestor := Scope (Prv_Ancestor); end loop; if Present (Prv_Ancestor) then Child_Parent := Scope (Prv_Ancestor); end if; end if; while Present (Curr_Parent) and then Curr_Parent /= Standard_Standard and then Curr_Parent /= Child_Parent loop Curr_Private := Curr_Private or else Is_Private_Library_Unit (Curr_Parent); Curr_Parent := Scope (Curr_Parent); end loop; if not Present (Curr_Parent) then Curr_Parent := Standard_Standard; end if; if Curr_Parent /= Child_Parent then if Ekind (Priv_Child) = E_Generic_Package and then Chars (Priv_Child) in Text_IO_Package_Name and then Chars (Scope (Scope (Priv_Child))) = Name_Ada then Error_Msg_NE ("& is a nested package, not a compilation unit", Name (Item), Priv_Child); else Error_Msg_N ("unit in with clause is private child unit!", Item); Error_Msg_NE ("current unit must also have parent&!", Item, Child_Parent); end if; elsif not Curr_Private and then Nkind (Lib_Unit) /= N_Package_Body and then Nkind (Lib_Unit) /= N_Subprogram_Body and then Nkind (Lib_Unit) /= N_Subunit then Error_Msg_NE ("current unit must also be private descendant of&", Item, Child_Parent); end if; end; end if; Next (Item); end loop; end Check_Private_Child_Unit; ---------------------- -- Check_Stub_Level -- ---------------------- procedure Check_Stub_Level (N : Node_Id) is Par : constant Node_Id := Parent (N); Kind : constant Node_Kind := Nkind (Par); begin if (Kind = N_Package_Body or else Kind = N_Subprogram_Body or else Kind = N_Task_Body or else Kind = N_Protected_Body) and then (Nkind (Parent (Par)) = N_Compilation_Unit or else Nkind (Parent (Par)) = N_Subunit) then null; -- In an instance, a missing stub appears at any level. A warning -- message will have been emitted already for the missing file. elsif not In_Instance then Error_Msg_N ("stub cannot appear in an inner scope", N); elsif Expander_Active then Error_Msg_N ("missing proper body", N); end if; end Check_Stub_Level; ------------------------ -- Expand_With_Clause -- ------------------------ procedure Expand_With_Clause (Nam : Node_Id; N : Node_Id) is Loc : constant Source_Ptr := Sloc (Nam); Ent : constant Entity_Id := Entity (Nam); Withn : Node_Id; P : Node_Id; function Build_Unit_Name (Nam : Node_Id) return Node_Id; function Build_Unit_Name (Nam : Node_Id) return Node_Id is Result : Node_Id; begin if Nkind (Nam) = N_Identifier then return New_Occurrence_Of (Entity (Nam), Loc); else Result := Make_Expanded_Name (Loc, Chars => Chars (Entity (Nam)), Prefix => Build_Unit_Name (Prefix (Nam)), Selector_Name => New_Occurrence_Of (Entity (Nam), Loc)); Set_Entity (Result, Entity (Nam)); return Result; end if; end Build_Unit_Name; begin New_Nodes_OK := New_Nodes_OK + 1; Withn := Make_With_Clause (Loc, Name => Build_Unit_Name (Nam)); P := Parent (Unit_Declaration_Node (Ent)); Set_Library_Unit (Withn, P); Set_Corresponding_Spec (Withn, Ent); Set_First_Name (Withn, True); Set_Implicit_With (Withn, True); Prepend (Withn, Context_Items (N)); Mark_Rewrite_Insertion (Withn); Install_Withed_Unit (Withn); if Nkind (Nam) = N_Expanded_Name then Expand_With_Clause (Prefix (Nam), N); end if; New_Nodes_OK := New_Nodes_OK - 1; end Expand_With_Clause; ----------------------- -- Get_Parent_Entity -- ----------------------- function Get_Parent_Entity (Unit : Node_Id) return Entity_Id is begin if Nkind (Unit) = N_Package_Instantiation then return Defining_Entity (Specification (Instance_Spec (Unit))); else return Defining_Entity (Unit); end if; end Get_Parent_Entity; ----------------------------- -- Implicit_With_On_Parent -- ----------------------------- procedure Implicit_With_On_Parent (Child_Unit : Node_Id; N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); P : constant Node_Id := Parent_Spec (Child_Unit); P_Unit : constant Node_Id := Unit (P); P_Name : Entity_Id := Get_Parent_Entity (P_Unit); Withn : Node_Id; function Build_Ancestor_Name (P : Node_Id) return Node_Id; -- Build prefix of child unit name. Recurse if needed. function Build_Unit_Name return Node_Id; -- If the unit is a child unit, build qualified name with all -- ancestors. ------------------------- -- Build_Ancestor_Name -- ------------------------- function Build_Ancestor_Name (P : Node_Id) return Node_Id is P_Ref : Node_Id := New_Reference_To (Defining_Entity (P), Loc); begin if No (Parent_Spec (P)) then return P_Ref; else return Make_Selected_Component (Loc, Prefix => Build_Ancestor_Name (Unit (Parent_Spec (P))), Selector_Name => P_Ref); end if; end Build_Ancestor_Name; --------------------- -- Build_Unit_Name -- --------------------- function Build_Unit_Name return Node_Id is Result : Node_Id; begin if No (Parent_Spec (P_Unit)) then return New_Reference_To (P_Name, Loc); else Result := Make_Expanded_Name (Loc, Chars => Chars (P_Name), Prefix => Build_Ancestor_Name (Unit (Parent_Spec (P_Unit))), Selector_Name => New_Reference_To (P_Name, Loc)); Set_Entity (Result, P_Name); return Result; end if; end Build_Unit_Name; -- Start of processing for Implicit_With_On_Parent begin New_Nodes_OK := New_Nodes_OK + 1; Withn := Make_With_Clause (Loc, Name => Build_Unit_Name); Set_Library_Unit (Withn, P); Set_Corresponding_Spec (Withn, P_Name); Set_First_Name (Withn, True); Set_Implicit_With (Withn, True); -- Node is placed at the beginning of the context items, so that -- subsequent use clauses on the parent can be validated. Prepend (Withn, Context_Items (N)); Mark_Rewrite_Insertion (Withn); Install_Withed_Unit (Withn); if Is_Child_Spec (P_Unit) then Implicit_With_On_Parent (P_Unit, N); end if; New_Nodes_OK := New_Nodes_OK - 1; end Implicit_With_On_Parent; --------------------- -- Install_Context -- --------------------- procedure Install_Context (N : Node_Id) is Lib_Unit : Node_Id := Unit (N); begin Install_Context_Clauses (N); if Is_Child_Spec (Lib_Unit) then Install_Parents (Lib_Unit, Private_Present (Parent (Lib_Unit))); end if; Check_With_Type_Clauses (N); end Install_Context; ----------------------------- -- Install_Context_Clauses -- ----------------------------- procedure Install_Context_Clauses (N : Node_Id) is Lib_Unit : Node_Id := Unit (N); Item : Node_Id; Uname_Node : Entity_Id; Check_Private : Boolean := False; Decl_Node : Node_Id; Lib_Parent : Entity_Id; begin -- Loop through context clauses to find the with/use clauses Item := First (Context_Items (N)); while Present (Item) loop -- Case of explicit WITH clause if Nkind (Item) = N_With_Clause and then not Implicit_With (Item) then -- If Name (Item) is not an entity name, something is wrong, and -- this will be detected in due course, for now ignore the item if not Is_Entity_Name (Name (Item)) then goto Continue; end if; Uname_Node := Entity (Name (Item)); if Is_Private_Descendant (Uname_Node) then Check_Private := True; end if; Install_Withed_Unit (Item); Decl_Node := Unit_Declaration_Node (Uname_Node); -- If the unit is a subprogram instance, it appears nested -- within a package that carries the parent information. if Is_Generic_Instance (Uname_Node) and then Ekind (Uname_Node) /= E_Package then Decl_Node := Parent (Parent (Decl_Node)); end if; if Is_Child_Spec (Decl_Node) then if Nkind (Name (Item)) = N_Expanded_Name then Expand_With_Clause (Prefix (Name (Item)), N); else -- if not an expanded name, the child unit must be a -- renaming, nothing to do. null; end if; elsif Nkind (Decl_Node) = N_Subprogram_Body and then not Acts_As_Spec (Parent (Decl_Node)) and then Is_Child_Spec (Unit (Library_Unit (Parent (Decl_Node)))) then Implicit_With_On_Parent (Unit (Library_Unit (Parent (Decl_Node))), N); end if; -- Check license conditions unless this is a dummy unit if Sloc (Library_Unit (Item)) /= No_Location then License_Check : declare Withl : constant License_Type := License (Source_Index (Get_Source_Unit (Library_Unit (Item)))); Unitl : constant License_Type := License (Source_Index (Current_Sem_Unit)); procedure License_Error; -- Signal error of bad license ------------------- -- License_Error -- ------------------- procedure License_Error is begin Error_Msg_N ("?license of with'ed unit & is incompatible", Name (Item)); end License_Error; -- Start of processing for License_Check begin case Unitl is when Unknown => null; when Restricted => if Withl = GPL then License_Error; end if; when GPL => if Withl = Restricted then License_Error; end if; when Modified_GPL => if Withl = Restricted or else Withl = GPL then License_Error; end if; when Unrestricted => null; end case; end License_Check; end if; -- Case of USE PACKAGE clause elsif Nkind (Item) = N_Use_Package_Clause then Analyze_Use_Package (Item); -- Case of USE TYPE clause elsif Nkind (Item) = N_Use_Type_Clause then Analyze_Use_Type (Item); -- Case of WITH TYPE clause -- A With_Type_Clause is processed when installing the context, -- because it is a visibility mechanism and does not create a -- semantic dependence on other units, as a With_Clause does. elsif Nkind (Item) = N_With_Type_Clause then Analyze_With_Type_Clause (Item); -- case of PRAGMA elsif Nkind (Item) = N_Pragma then Analyze (Item); end if; <> Next (Item); end loop; if Is_Child_Spec (Lib_Unit) then -- The unit also has implicit withs on its own parents. if No (Context_Items (N)) then Set_Context_Items (N, New_List); end if; Implicit_With_On_Parent (Lib_Unit, N); end if; -- If the unit is a body, the context of the specification must also -- be installed. if Nkind (Lib_Unit) = N_Package_Body or else (Nkind (Lib_Unit) = N_Subprogram_Body and then not Acts_As_Spec (N)) then Install_Context (Library_Unit (N)); if Is_Child_Spec (Unit (Library_Unit (N))) then -- If the unit is the body of a public child unit, the private -- declarations of the parent must be made visible. If the child -- unit is private, the private declarations have been installed -- already in the call to Install_Parents for the spec. Installing -- private declarations must be done for all ancestors of public -- child units. In addition, sibling units mentioned in the -- context clause of the body are directly visible. declare Lib_Spec : Node_Id := Unit (Library_Unit (N)); P : Node_Id; P_Name : Entity_Id; begin while Is_Child_Spec (Lib_Spec) loop P := Unit (Parent_Spec (Lib_Spec)); if not (Private_Present (Parent (Lib_Spec))) then P_Name := Defining_Entity (P); Install_Private_Declarations (P_Name); Set_Use (Private_Declarations (Specification (P))); end if; Lib_Spec := P; end loop; end; end if; -- For a package body, children in context are immediately visible Install_Siblings (Defining_Entity (Unit (Library_Unit (N))), N); end if; if Nkind (Lib_Unit) = N_Generic_Package_Declaration or else Nkind (Lib_Unit) = N_Generic_Subprogram_Declaration or else Nkind (Lib_Unit) = N_Package_Declaration or else Nkind (Lib_Unit) = N_Subprogram_Declaration then if Is_Child_Spec (Lib_Unit) then Lib_Parent := Defining_Entity (Unit (Parent_Spec (Lib_Unit))); Set_Is_Private_Descendant (Defining_Entity (Lib_Unit), Is_Private_Descendant (Lib_Parent) or else Private_Present (Parent (Lib_Unit))); else Set_Is_Private_Descendant (Defining_Entity (Lib_Unit), Private_Present (Parent (Lib_Unit))); end if; end if; if Check_Private then Check_Private_Child_Unit (N); end if; end Install_Context_Clauses; --------------------- -- Install_Parents -- --------------------- procedure Install_Parents (Lib_Unit : Node_Id; Is_Private : Boolean) is P : Node_Id; E_Name : Entity_Id; P_Name : Entity_Id; P_Spec : Node_Id; begin P := Unit (Parent_Spec (Lib_Unit)); P_Name := Get_Parent_Entity (P); if Etype (P_Name) = Any_Type then return; end if; if Ekind (P_Name) = E_Generic_Package and then Nkind (Lib_Unit) /= N_Generic_Subprogram_Declaration and then Nkind (Lib_Unit) /= N_Generic_Package_Declaration and then Nkind (Lib_Unit) not in N_Generic_Renaming_Declaration then Error_Msg_N ("child of a generic package must be a generic unit", Lib_Unit); elsif not Is_Package (P_Name) then Error_Msg_N ("parent unit must be package or generic package", Lib_Unit); raise Unrecoverable_Error; elsif Present (Renamed_Object (P_Name)) then Error_Msg_N ("parent unit cannot be a renaming", Lib_Unit); raise Unrecoverable_Error; -- Verify that a child of an instance is itself an instance, or -- the renaming of one. Given that an instance that is a unit is -- replaced with a package declaration, check against the original -- node. elsif Nkind (Original_Node (P)) = N_Package_Instantiation and then Nkind (Lib_Unit) not in N_Renaming_Declaration and then Nkind (Original_Node (Lib_Unit)) not in N_Generic_Instantiation then Error_Msg_N ("child of an instance must be an instance or renaming", Lib_Unit); end if; -- This is the recursive call that ensures all parents are loaded if Is_Child_Spec (P) then Install_Parents (P, Is_Private or else Private_Present (Parent (Lib_Unit))); end if; -- Now we can install the context for this parent Install_Context_Clauses (Parent_Spec (Lib_Unit)); Install_Siblings (P_Name, Parent (Lib_Unit)); -- The child unit is in the declarative region of the parent. The -- parent must therefore appear in the scope stack and be visible, -- as when compiling the corresponding body. If the child unit is -- private or it is a package body, private declarations must be -- accessible as well. Use declarations in the parent must also -- be installed. Finally, other child units of the same parent that -- are in the context are immediately visible. -- Find entity for compilation unit, and set its private descendant -- status as needed. E_Name := Defining_Entity (Lib_Unit); Set_Is_Child_Unit (E_Name); Set_Is_Private_Descendant (E_Name, Is_Private_Descendant (P_Name) or else Private_Present (Parent (Lib_Unit))); P_Spec := Specification (Unit_Declaration_Node (P_Name)); New_Scope (P_Name); -- Save current visibility of unit Scope_Stack.Table (Scope_Stack.Last).Previous_Visibility := Is_Immediately_Visible (P_Name); Set_Is_Immediately_Visible (P_Name); Install_Visible_Declarations (P_Name); Set_Use (Visible_Declarations (P_Spec)); if Is_Private or else Private_Present (Parent (Lib_Unit)) then Install_Private_Declarations (P_Name); Set_Use (Private_Declarations (P_Spec)); end if; end Install_Parents; ---------------------- -- Install_Siblings -- ---------------------- procedure Install_Siblings (U_Name : Entity_Id; N : Node_Id) is Item : Node_Id; Id : Entity_Id; Prev : Entity_Id; function Is_Ancestor (E : Entity_Id) return Boolean; -- Determine whether the scope of a child unit is an ancestor of -- the current unit. -- Shouldn't this be somewhere more general ??? function Is_Ancestor (E : Entity_Id) return Boolean is Par : Entity_Id; begin Par := U_Name; while Present (Par) and then Par /= Standard_Standard loop if Par = E then return True; end if; Par := Scope (Par); end loop; return False; end Is_Ancestor; -- Start of processing for Install_Siblings begin -- Iterate over explicit with clauses, and check whether the -- scope of each entity is an ancestor of the current unit. Item := First (Context_Items (N)); while Present (Item) loop if Nkind (Item) = N_With_Clause and then not Implicit_With (Item) then Id := Entity (Name (Item)); if Is_Child_Unit (Id) and then Is_Ancestor (Scope (Id)) then Set_Is_Immediately_Visible (Id); Prev := Current_Entity (Id); -- Check for the presence of another unit in the context, -- that may be inadvertently hidden by the child. if Present (Prev) and then Is_Immediately_Visible (Prev) and then not Is_Child_Unit (Prev) then declare Clause : Node_Id; begin Clause := First (Context_Items (N)); while Present (Clause) loop if Nkind (Clause) = N_With_Clause and then Entity (Name (Clause)) = Prev then Error_Msg_NE ("child unit& hides compilation unit " & "with the same name?", Name (Item), Id); exit; end if; Next (Clause); end loop; end; end if; -- the With_Clause may be on a grand-child, which makes -- the child immediately visible. elsif Is_Child_Unit (Scope (Id)) and then Is_Ancestor (Scope (Scope (Id))) then Set_Is_Immediately_Visible (Scope (Id)); end if; end if; Next (Item); end loop; end Install_Siblings; ------------------------- -- Install_Withed_Unit -- ------------------------- procedure Install_Withed_Unit (With_Clause : Node_Id) is Uname : Entity_Id := Entity (Name (With_Clause)); P : constant Entity_Id := Scope (Uname); begin -- We do not apply the restrictions to an internal unit unless -- we are compiling the internal unit as a main unit. This check -- is also skipped for dummy units (for missing packages). if Sloc (Uname) /= No_Location and then (not Is_Internal_File_Name (Unit_File_Name (Current_Sem_Unit)) or else Current_Sem_Unit = Main_Unit) then Check_Restricted_Unit (Unit_Name (Get_Source_Unit (Uname)), With_Clause); end if; if P /= Standard_Standard then -- If the unit is not analyzed after analysis of the with clause, -- and it is an instantiation, then it awaits a body and is the main -- unit. Its appearance in the context of some other unit indicates -- a circular dependency (DEC suite perversity). if not Analyzed (Uname) and then Nkind (Parent (Uname)) = N_Package_Instantiation then Error_Msg_N ("instantiation depends on itself", Name (With_Clause)); elsif not Is_Visible_Child_Unit (Uname) then Set_Is_Visible_Child_Unit (Uname); if Is_Generic_Instance (Uname) and then Ekind (Uname) in Subprogram_Kind then -- Set flag as well on the visible entity that denotes the -- instance, which renames the current one. Set_Is_Visible_Child_Unit (Related_Instance (Defining_Entity (Unit (Library_Unit (With_Clause))))); null; end if; -- The parent unit may have been installed already, and -- may have appeared in a use clause. if In_Use (Scope (Uname)) then Set_Is_Potentially_Use_Visible (Uname); end if; Set_Context_Installed (With_Clause); end if; elsif not Is_Immediately_Visible (Uname) then Set_Is_Immediately_Visible (Uname); Set_Context_Installed (With_Clause); end if; -- A with-clause overrides a with-type clause: there are no restric- -- tions on the use of package entities. if Ekind (Uname) = E_Package then Set_From_With_Type (Uname, False); end if; end Install_Withed_Unit; ------------------- -- Is_Child_Spec -- ------------------- function Is_Child_Spec (Lib_Unit : Node_Id) return Boolean is K : constant Node_Kind := Nkind (Lib_Unit); begin return (K in N_Generic_Declaration or else K in N_Generic_Instantiation or else K in N_Generic_Renaming_Declaration or else K = N_Package_Declaration or else K = N_Package_Renaming_Declaration or else K = N_Subprogram_Declaration or else K = N_Subprogram_Renaming_Declaration) and then Present (Parent_Spec (Lib_Unit)); end Is_Child_Spec; ----------------------- -- Load_Needed_Body -- ----------------------- -- N is a generic unit named in a with clause, or else it is -- a unit that contains a generic unit or an inlined function. -- In order to perform an instantiation, the body of the unit -- must be present. If the unit itself is generic, we assume -- that an instantiation follows, and load and analyze the body -- unconditionally. This forces analysis of the spec as well. -- If the unit is not generic, but contains a generic unit, it -- is loaded on demand, at the point of instantiation (see ch12). procedure Load_Needed_Body (N : Node_Id; OK : out Boolean) is Body_Name : Unit_Name_Type; Unum : Unit_Number_Type; Save_Style_Check : constant Boolean := Opt.Style_Check; -- The loading and analysis is done with style checks off begin if not GNAT_Mode then Style_Check := False; end if; Body_Name := Get_Body_Name (Get_Unit_Name (Unit (N))); Unum := Load_Unit (Load_Name => Body_Name, Required => False, Subunit => False, Error_Node => N, Renamings => True); if Unum = No_Unit then OK := False; else Compiler_State := Analyzing; -- reset after load if not Fatal_Error (Unum) then if Debug_Flag_L then Write_Str ("*** Loaded generic body"); Write_Eol; end if; Semantics (Cunit (Unum)); end if; OK := True; end if; Style_Check := Save_Style_Check; end Load_Needed_Body; -------------------- -- Remove_Context -- -------------------- procedure Remove_Context (N : Node_Id) is Lib_Unit : constant Node_Id := Unit (N); begin -- If this is a child unit, first remove the parent units. if Is_Child_Spec (Lib_Unit) then Remove_Parents (Lib_Unit); end if; Remove_Context_Clauses (N); end Remove_Context; ---------------------------- -- Remove_Context_Clauses -- ---------------------------- procedure Remove_Context_Clauses (N : Node_Id) is Item : Node_Id; Unit_Name : Entity_Id; begin -- Loop through context items and undo with_clauses and use_clauses. Item := First (Context_Items (N)); while Present (Item) loop -- We are interested only in with clauses which got installed -- on entry, as indicated by their Context_Installed flag set if Nkind (Item) = N_With_Clause and then Context_Installed (Item) then -- Remove items from one with'ed unit Unit_Name := Entity (Name (Item)); Remove_Unit_From_Visibility (Unit_Name); Set_Context_Installed (Item, False); elsif Nkind (Item) = N_Use_Package_Clause then End_Use_Package (Item); elsif Nkind (Item) = N_Use_Type_Clause then End_Use_Type (Item); elsif Nkind (Item) = N_With_Type_Clause then Remove_With_Type_Clause (Name (Item)); end if; Next (Item); end loop; end Remove_Context_Clauses; -------------------- -- Remove_Parents -- -------------------- procedure Remove_Parents (Lib_Unit : Node_Id) is P : Node_Id; P_Name : Entity_Id; E : Entity_Id; Vis : constant Boolean := Scope_Stack.Table (Scope_Stack.Last).Previous_Visibility; begin if Is_Child_Spec (Lib_Unit) then P := Unit (Parent_Spec (Lib_Unit)); P_Name := Defining_Entity (P); Remove_Context_Clauses (Parent_Spec (Lib_Unit)); End_Package_Scope (P_Name); Set_Is_Immediately_Visible (P_Name, Vis); -- Remove from visibility the siblings as well, which are directly -- visible while the parent is in scope. E := First_Entity (P_Name); while Present (E) loop if Is_Child_Unit (E) then Set_Is_Immediately_Visible (E, False); end if; Next_Entity (E); end loop; Set_In_Package_Body (P_Name, False); -- This is the recursive call to remove the context of any -- higher level parent. This recursion ensures that all parents -- are removed in the reverse order of their installation. Remove_Parents (P); end if; end Remove_Parents; ----------------------------- -- Remove_With_Type_Clause -- ----------------------------- procedure Remove_With_Type_Clause (Name : Node_Id) is Typ : Entity_Id; P : Entity_Id; procedure Unchain (E : Entity_Id); -- Remove entity from visibility list. procedure Unchain (E : Entity_Id) is Prev : Entity_Id; begin Prev := Current_Entity (E); -- Package entity may appear is several with_type_clauses, and -- may have been removed already. if No (Prev) then return; elsif Prev = E then Set_Name_Entity_Id (Chars (E), Homonym (E)); else while Present (Prev) and then Homonym (Prev) /= E loop Prev := Homonym (Prev); end loop; if (Present (Prev)) then Set_Homonym (Prev, Homonym (E)); end if; end if; end Unchain; begin if Nkind (Name) = N_Selected_Component then Typ := Entity (Selector_Name (Name)); if No (Typ) then -- error in declaration. return; end if; else return; end if; P := Scope (Typ); -- If the exporting package has been analyzed, it has appeared in the -- context already and should be left alone. Otherwise, remove from -- visibility. if not Analyzed (Unit_Declaration_Node (P)) then Unchain (P); Unchain (Typ); Set_Is_Frozen (Typ, False); end if; if Ekind (Typ) = E_Record_Type then Set_From_With_Type (Class_Wide_Type (Typ), False); Set_From_With_Type (Typ, False); end if; Set_From_With_Type (P, False); -- If P is a child unit, remove parents as well. P := Scope (P); while Present (P) and then P /= Standard_Standard loop Set_From_With_Type (P, False); if not Analyzed (Unit_Declaration_Node (P)) then Unchain (P); end if; P := Scope (P); end loop; -- The back-end needs to know that an access type is imported, so it -- does not need elaboration and can appear in a mutually recursive -- record definition, so the imported flag on an access type is -- preserved. end Remove_With_Type_Clause; --------------------------------- -- Remove_Unit_From_Visibility -- --------------------------------- procedure Remove_Unit_From_Visibility (Unit_Name : Entity_Id) is P : Entity_Id := Scope (Unit_Name); begin if Debug_Flag_I then Write_Str ("remove withed unit "); Write_Name (Chars (Unit_Name)); Write_Eol; end if; if P /= Standard_Standard then Set_Is_Visible_Child_Unit (Unit_Name, False); end if; Set_Is_Potentially_Use_Visible (Unit_Name, False); Set_Is_Immediately_Visible (Unit_Name, False); end Remove_Unit_From_Visibility; end Sem_Ch10;