------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- I N L I N E -- -- -- -- 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 Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Ch7; use Exp_Ch7; with Exp_Ch11; use Exp_Ch11; with Exp_Tss; use Exp_Tss; with Fname; use Fname; with Fname.UF; use Fname.UF; with Lib; use Lib; with Nlists; use Nlists; with Opt; use Opt; with Sem_Ch8; use Sem_Ch8; with Sem_Ch10; use Sem_Ch10; with Sem_Ch12; use Sem_Ch12; with Sem_Util; use Sem_Util; with Sinfo; use Sinfo; with Snames; use Snames; with Stand; use Stand; with Uname; use Uname; package body Inline is -------------------- -- Inlined Bodies -- -------------------- -- Inlined functions are actually placed in line by the backend if the -- corresponding bodies are available (i.e. compiled). Whenever we find -- a call to an inlined subprogram, we add the name of the enclosing -- compilation unit to a worklist. After all compilation, and after -- expansion of generic bodies, we traverse the list of pending bodies -- and compile them as well. package Inlined_Bodies is new Table.Table ( Table_Component_Type => Entity_Id, Table_Index_Type => Int, Table_Low_Bound => 0, Table_Initial => Alloc.Inlined_Bodies_Initial, Table_Increment => Alloc.Inlined_Bodies_Increment, Table_Name => "Inlined_Bodies"); ----------------------- -- Inline Processing -- ----------------------- -- For each call to an inlined subprogram, we make entries in a table -- that stores caller and callee, and indicates a prerequisite from -- one to the other. We also record the compilation unit that contains -- the callee. After analyzing the bodies of all such compilation units, -- we produce a list of subprograms in topological order, for use by the -- back-end. If P2 is a prerequisite of P1, then P1 calls P2, and for -- proper inlining the back-end must analyze the body of P2 before that of -- P1. The code below guarantees that the transitive closure of inlined -- subprograms called from the main compilation unit is made available to -- the code generator. Last_Inlined : Entity_Id := Empty; -- For each entry in the table we keep a list of successors in topological -- order, i.e. callers of the current subprogram. type Subp_Index is new Nat; No_Subp : constant Subp_Index := 0; -- The subprogram entities are hashed into the Inlined table. Num_Hash_Headers : constant := 512; Hash_Headers : array (Subp_Index range 0 .. Num_Hash_Headers - 1) of Subp_Index; type Succ_Index is new Nat; No_Succ : constant Succ_Index := 0; type Succ_Info is record Subp : Subp_Index; Next : Succ_Index; end record; -- The following table stores list elements for the successor lists. -- These lists cannot be chained directly through entries in the Inlined -- table, because a given subprogram can appear in several such lists. package Successors is new Table.Table ( Table_Component_Type => Succ_Info, Table_Index_Type => Succ_Index, Table_Low_Bound => 1, Table_Initial => Alloc.Successors_Initial, Table_Increment => Alloc.Successors_Increment, Table_Name => "Successors"); type Subp_Info is record Name : Entity_Id := Empty; First_Succ : Succ_Index := No_Succ; Count : Integer := 0; Listed : Boolean := False; Main_Call : Boolean := False; Next : Subp_Index := No_Subp; Next_Nopred : Subp_Index := No_Subp; end record; package Inlined is new Table.Table ( Table_Component_Type => Subp_Info, Table_Index_Type => Subp_Index, Table_Low_Bound => 1, Table_Initial => Alloc.Inlined_Initial, Table_Increment => Alloc.Inlined_Increment, Table_Name => "Inlined"); ----------------------- -- Local Subprograms -- ----------------------- function Scope_In_Main_Unit (Scop : Entity_Id) return Boolean; -- Return True if Scop is in the main unit or its spec, or in a -- parent of the main unit if it is a child unit. procedure Add_Call (Called : Entity_Id; Caller : Entity_Id := Empty); -- Make two entries in Inlined table, for an inlined subprogram being -- called, and for the inlined subprogram that contains the call. If -- the call is in the main compilation unit, Caller is Empty. function Add_Subp (E : Entity_Id) return Subp_Index; -- Make entry in Inlined table for subprogram E, or return table index -- that already holds E. function Has_Initialized_Type (E : Entity_Id) return Boolean; -- If a candidate for inlining contains type declarations for types with -- non-trivial initialization procedures, they are not worth inlining. function Is_Nested (E : Entity_Id) return Boolean; -- If the function is nested inside some other function, it will -- always be compiled if that function is, so don't add it to the -- inline list. We cannot compile a nested function outside the -- scope of the containing function anyway. This is also the case if -- the function is defined in a task body or within an entry (for -- example, an initialization procedure). procedure Add_Inlined_Subprogram (Index : Subp_Index); -- Add subprogram to Inlined List once all of its predecessors have been -- placed on the list. Decrement the count of all its successors, and -- add them to list (recursively) if count drops to zero. ------------------------------ -- Deferred Cleanup Actions -- ------------------------------ -- The cleanup actions for scopes that contain instantiations is delayed -- until after expansion of those instantiations, because they may -- contain finalizable objects or tasks that affect the cleanup code. -- A scope that contains instantiations only needs to be finalized once, -- even if it contains more than one instance. We keep a list of scopes -- that must still be finalized, and call cleanup_actions after all the -- instantiations have been completed. To_Clean : Elist_Id; procedure Add_Scope_To_Clean (Inst : Entity_Id); -- Build set of scopes on which cleanup actions must be performed. procedure Cleanup_Scopes; -- Complete cleanup actions on scopes that need it. -------------- -- Add_Call -- -------------- procedure Add_Call (Called : Entity_Id; Caller : Entity_Id := Empty) is P1 : Subp_Index := Add_Subp (Called); P2 : Subp_Index; J : Succ_Index; begin if Present (Caller) then P2 := Add_Subp (Caller); -- Add P2 to the list of successors of P1, if not already there. -- Note that P2 may contain more than one call to P1, and only -- one needs to be recorded. J := Inlined.Table (P1).First_Succ; while J /= No_Succ loop if Successors.Table (J).Subp = P2 then return; end if; J := Successors.Table (J).Next; end loop; -- On exit, make a successor entry for P2. Successors.Increment_Last; Successors.Table (Successors.Last).Subp := P2; Successors.Table (Successors.Last).Next := Inlined.Table (P1).First_Succ; Inlined.Table (P1).First_Succ := Successors.Last; Inlined.Table (P2).Count := Inlined.Table (P2).Count + 1; else Inlined.Table (P1).Main_Call := True; end if; end Add_Call; ---------------------- -- Add_Inlined_Body -- ---------------------- procedure Add_Inlined_Body (E : Entity_Id) is Pack : Entity_Id; Comp_Unit : Node_Id; function Must_Inline return Boolean; -- Inlining is only done if the call statement N is in the main unit, -- or within the body of another inlined subprogram. function Must_Inline return Boolean is Scop : Entity_Id := Current_Scope; Comp : Node_Id; begin -- Check if call is in main unit. while Scope (Scop) /= Standard_Standard and then not Is_Child_Unit (Scop) loop Scop := Scope (Scop); end loop; Comp := Parent (Scop); while Nkind (Comp) /= N_Compilation_Unit loop Comp := Parent (Comp); end loop; if (Comp = Cunit (Main_Unit) or else Comp = Library_Unit (Cunit (Main_Unit))) then Add_Call (E); return True; end if; -- Call is not in main unit. See if it's in some inlined -- subprogram. Scop := Current_Scope; while Scope (Scop) /= Standard_Standard and then not Is_Child_Unit (Scop) loop if Is_Overloadable (Scop) and then Is_Inlined (Scop) then Add_Call (E, Scop); return True; end if; Scop := Scope (Scop); end loop; return False; end Must_Inline; -- Start of processing for Add_Inlined_Body begin -- Find unit containing E, and add to list of inlined bodies if needed. -- If the body is already present, no need to load any other unit. This -- is the case for an initialization procedure, which appears in the -- package declaration that contains the type. It is also the case if -- the body has already been analyzed. Finally, if the unit enclosing -- E is an instance, the instance body will be analyzed in any case, -- and there is no need to add the enclosing unit (whose body might not -- be available). -- Library-level functions must be handled specially, because there is -- no enclosing package to retrieve. In this case, it is the body of -- the function that will have to be loaded. if not Is_Abstract (E) and then not Is_Nested (E) and then Convention (E) /= Convention_Protected then Pack := Scope (E); if Must_Inline and then Ekind (Pack) = E_Package then Set_Is_Called (E); Comp_Unit := Parent (Pack); if Pack = Standard_Standard then -- Library-level inlined function. Add function iself to -- list of needed units. Inlined_Bodies.Increment_Last; Inlined_Bodies.Table (Inlined_Bodies.Last) := E; elsif Is_Generic_Instance (Pack) then null; elsif not Is_Inlined (Pack) and then not Has_Completion (E) and then not Scope_In_Main_Unit (Pack) then Set_Is_Inlined (Pack); Inlined_Bodies.Increment_Last; Inlined_Bodies.Table (Inlined_Bodies.Last) := Pack; end if; end if; end if; end Add_Inlined_Body; ---------------------------- -- Add_Inlined_Subprogram -- ---------------------------- procedure Add_Inlined_Subprogram (Index : Subp_Index) is E : constant Entity_Id := Inlined.Table (Index).Name; Succ : Succ_Index; Subp : Subp_Index; begin -- Insert the current subprogram in the list of inlined subprograms if not Scope_In_Main_Unit (E) and then Is_Inlined (E) and then not Is_Nested (E) and then not Has_Initialized_Type (E) then if No (Last_Inlined) then Set_First_Inlined_Subprogram (Cunit (Main_Unit), E); else Set_Next_Inlined_Subprogram (Last_Inlined, E); end if; Last_Inlined := E; end if; Inlined.Table (Index).Listed := True; Succ := Inlined.Table (Index).First_Succ; while Succ /= No_Succ loop Subp := Successors.Table (Succ).Subp; Inlined.Table (Subp).Count := Inlined.Table (Subp).Count - 1; if Inlined.Table (Subp).Count = 0 then Add_Inlined_Subprogram (Subp); end if; Succ := Successors.Table (Succ).Next; end loop; end Add_Inlined_Subprogram; ------------------------ -- Add_Scope_To_Clean -- ------------------------ procedure Add_Scope_To_Clean (Inst : Entity_Id) is Elmt : Elmt_Id; Scop : Entity_Id := Enclosing_Dynamic_Scope (Inst); begin -- If the instance appears in a library-level package declaration, -- all finalization is global, and nothing needs doing here. if Scop = Standard_Standard then return; end if; Elmt := First_Elmt (To_Clean); while Present (Elmt) loop if Node (Elmt) = Scop then return; end if; Elmt := Next_Elmt (Elmt); end loop; Append_Elmt (Scop, To_Clean); end Add_Scope_To_Clean; -------------- -- Add_Subp -- -------------- function Add_Subp (E : Entity_Id) return Subp_Index is Index : Subp_Index := Subp_Index (E) mod Num_Hash_Headers; J : Subp_Index; procedure New_Entry; -- Initialize entry in Inlined table. procedure New_Entry is begin Inlined.Increment_Last; Inlined.Table (Inlined.Last).Name := E; Inlined.Table (Inlined.Last).First_Succ := No_Succ; Inlined.Table (Inlined.Last).Count := 0; Inlined.Table (Inlined.Last).Listed := False; Inlined.Table (Inlined.Last).Main_Call := False; Inlined.Table (Inlined.Last).Next := No_Subp; Inlined.Table (Inlined.Last).Next_Nopred := No_Subp; end New_Entry; -- Start of processing for Add_Subp begin if Hash_Headers (Index) = No_Subp then New_Entry; Hash_Headers (Index) := Inlined.Last; return Inlined.Last; else J := Hash_Headers (Index); while J /= No_Subp loop if Inlined.Table (J).Name = E then return J; else Index := J; J := Inlined.Table (J).Next; end if; end loop; -- On exit, subprogram was not found. Enter in table. Index is -- the current last entry on the hash chain. New_Entry; Inlined.Table (Index).Next := Inlined.Last; return Inlined.Last; end if; end Add_Subp; ---------------------------- -- Analyze_Inlined_Bodies -- ---------------------------- procedure Analyze_Inlined_Bodies is Comp_Unit : Node_Id; J : Int; Pack : Entity_Id; S : Succ_Index; begin Analyzing_Inlined_Bodies := False; if Serious_Errors_Detected = 0 then New_Scope (Standard_Standard); J := 0; while J <= Inlined_Bodies.Last and then Serious_Errors_Detected = 0 loop Pack := Inlined_Bodies.Table (J); while Present (Pack) and then Scope (Pack) /= Standard_Standard and then not Is_Child_Unit (Pack) loop Pack := Scope (Pack); end loop; Comp_Unit := Parent (Pack); while Present (Comp_Unit) and then Nkind (Comp_Unit) /= N_Compilation_Unit loop Comp_Unit := Parent (Comp_Unit); end loop; -- Load the body, unless it the main unit, or is an instance -- whose body has already been analyzed. if Present (Comp_Unit) and then Comp_Unit /= Cunit (Main_Unit) and then Body_Required (Comp_Unit) and then (Nkind (Unit (Comp_Unit)) /= N_Package_Declaration or else No (Corresponding_Body (Unit (Comp_Unit)))) then declare Bname : constant Unit_Name_Type := Get_Body_Name (Get_Unit_Name (Unit (Comp_Unit))); OK : Boolean; begin if not Is_Loaded (Bname) then Load_Needed_Body (Comp_Unit, OK); if not OK then Error_Msg_Unit_1 := Bname; Error_Msg_N ("one or more inlined subprograms accessed in $!", Comp_Unit); Error_Msg_Name_1 := Get_File_Name (Bname, Subunit => False); Error_Msg_N ("\but file{ was not found!", Comp_Unit); raise Unrecoverable_Error; end if; end if; end; end if; J := J + 1; end loop; -- The analysis of required bodies may have produced additional -- generic instantiations. To obtain further inlining, we perform -- another round of generic body instantiations. Establishing a -- fully recursive loop between inlining and generic instantiations -- is unlikely to yield more than this one additional pass. Instantiate_Bodies; -- The list of inlined subprograms is an overestimate, because -- it includes inlined functions called from functions that are -- compiled as part of an inlined package, but are not themselves -- called. An accurate computation of just those subprograms that -- are needed requires that we perform a transitive closure over -- the call graph, starting from calls in the main program. Here -- we do one step of the inverse transitive closure, and reset -- the Is_Called flag on subprograms all of whose callers are not. for Index in Inlined.First .. Inlined.Last loop S := Inlined.Table (Index).First_Succ; if S /= No_Succ and then not Inlined.Table (Index).Main_Call then Set_Is_Called (Inlined.Table (Index).Name, False); while S /= No_Succ loop if Is_Called (Inlined.Table (Successors.Table (S).Subp).Name) or else Inlined.Table (Successors.Table (S).Subp).Main_Call then Set_Is_Called (Inlined.Table (Index).Name); exit; end if; S := Successors.Table (S).Next; end loop; end if; end loop; -- Now that the units are compiled, chain the subprograms within -- that are called and inlined. Produce list of inlined subprograms -- sorted in topological order. Start with all subprograms that -- have no prerequisites, i.e. inlined subprograms that do not call -- other inlined subprograms. for Index in Inlined.First .. Inlined.Last loop if Is_Called (Inlined.Table (Index).Name) and then Inlined.Table (Index).Count = 0 and then not Inlined.Table (Index).Listed then Add_Inlined_Subprogram (Index); end if; end loop; -- Because Add_Inlined_Subprogram treats recursively nodes that have -- no prerequisites left, at the end of the loop all subprograms -- must have been listed. If there are any unlisted subprograms -- left, there must be some recursive chains that cannot be inlined. for Index in Inlined.First .. Inlined.Last loop if Is_Called (Inlined.Table (Index).Name) and then Inlined.Table (Index).Count /= 0 and then not Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Inlined.Table (Index).Name))) then Error_Msg_N ("& cannot be inlined?", Inlined.Table (Index).Name); -- A warning on the first one might be sufficient. end if; end loop; Pop_Scope; end if; end Analyze_Inlined_Bodies; -------------------------------- -- Check_Body_For_Inlining -- -------------------------------- procedure Check_Body_For_Inlining (N : Node_Id; P : Entity_Id) is Bname : Unit_Name_Type; E : Entity_Id; OK : Boolean; begin if Is_Compilation_Unit (P) and then not Is_Generic_Instance (P) then Bname := Get_Body_Name (Get_Unit_Name (Unit (N))); E := First_Entity (P); while Present (E) loop if Has_Pragma_Inline (E) then if not Is_Loaded (Bname) then Load_Needed_Body (N, OK); if not OK and then Ineffective_Inline_Warnings then Error_Msg_Unit_1 := Bname; Error_Msg_N ("unable to inline subprograms defined in $?", P); Error_Msg_N ("\body not found?", P); return; end if; end if; return; end if; Next_Entity (E); end loop; end if; end Check_Body_For_Inlining; -------------------- -- Cleanup_Scopes -- -------------------- procedure Cleanup_Scopes is Elmt : Elmt_Id; Decl : Node_Id; Scop : Entity_Id; begin Elmt := First_Elmt (To_Clean); while Present (Elmt) loop Scop := Node (Elmt); if Ekind (Scop) = E_Entry then Scop := Protected_Body_Subprogram (Scop); end if; if Ekind (Scop) = E_Block then Decl := Parent (Block_Node (Scop)); else Decl := Unit_Declaration_Node (Scop); if Nkind (Decl) = N_Subprogram_Declaration or else Nkind (Decl) = N_Task_Type_Declaration or else Nkind (Decl) = N_Subprogram_Body_Stub then Decl := Unit_Declaration_Node (Corresponding_Body (Decl)); end if; end if; New_Scope (Scop); Expand_Cleanup_Actions (Decl); End_Scope; Elmt := Next_Elmt (Elmt); end loop; end Cleanup_Scopes; -------------------------- -- Has_Initialized_Type -- -------------------------- function Has_Initialized_Type (E : Entity_Id) return Boolean is E_Body : constant Node_Id := Get_Subprogram_Body (E); Decl : Node_Id; begin if No (E_Body) then -- imported subprogram return False; else Decl := First (Declarations (E_Body)); while Present (Decl) loop if Nkind (Decl) = N_Full_Type_Declaration and then Present (Init_Proc (Defining_Identifier (Decl))) then return True; end if; Next (Decl); end loop; end if; return False; end Has_Initialized_Type; ---------------- -- Initialize -- ---------------- procedure Initialize is begin Analyzing_Inlined_Bodies := False; Pending_Descriptor.Init; Pending_Instantiations.Init; Inlined_Bodies.Init; Successors.Init; Inlined.Init; for J in Hash_Headers'Range loop Hash_Headers (J) := No_Subp; end loop; end Initialize; ------------------------ -- Instantiate_Bodies -- ------------------------ -- Generic bodies contain all the non-local references, so an -- instantiation does not need any more context than Standard -- itself, even if the instantiation appears in an inner scope. -- Generic associations have verified that the contract model is -- satisfied, so that any error that may occur in the analysis of -- the body is an internal error. procedure Instantiate_Bodies is J : Int; Info : Pending_Body_Info; begin if Serious_Errors_Detected = 0 then Expander_Active := (Operating_Mode = Opt.Generate_Code); New_Scope (Standard_Standard); To_Clean := New_Elmt_List; if Is_Generic_Unit (Cunit_Entity (Main_Unit)) then Start_Generic; end if; -- A body instantiation may generate additional instantiations, so -- the following loop must scan to the end of a possibly expanding -- set (that's why we can't simply use a FOR loop here). J := 0; while J <= Pending_Instantiations.Last and then Serious_Errors_Detected = 0 loop Info := Pending_Instantiations.Table (J); -- If the instantiation node is absent, it has been removed -- as part of unreachable code. if No (Info.Inst_Node) then null; elsif Nkind (Info. Act_Decl) = N_Package_Declaration then Instantiate_Package_Body (Info); Add_Scope_To_Clean (Defining_Entity (Info.Act_Decl)); else Instantiate_Subprogram_Body (Info); end if; J := J + 1; end loop; -- Reset the table of instantiations. Additional instantiations -- may be added through inlining, when additional bodies are -- analyzed. Pending_Instantiations.Init; -- We can now complete the cleanup actions of scopes that contain -- pending instantiations (skipped for generic units, since we -- never need any cleanups in generic units). -- pending instantiations. if Expander_Active and then not Is_Generic_Unit (Main_Unit_Entity) then Cleanup_Scopes; -- Also generate subprogram descriptors that were delayed for J in Pending_Descriptor.First .. Pending_Descriptor.Last loop declare Ent : constant Entity_Id := Pending_Descriptor.Table (J); begin if Is_Subprogram (Ent) then Generate_Subprogram_Descriptor_For_Subprogram (Get_Subprogram_Body (Ent), Ent); elsif Ekind (Ent) = E_Package then Generate_Subprogram_Descriptor_For_Package (Parent (Declaration_Node (Ent)), Ent); elsif Ekind (Ent) = E_Package_Body then Generate_Subprogram_Descriptor_For_Package (Declaration_Node (Ent), Ent); end if; end; end loop; elsif Is_Generic_Unit (Cunit_Entity (Main_Unit)) then End_Generic; end if; Pop_Scope; end if; end Instantiate_Bodies; --------------- -- Is_Nested -- --------------- function Is_Nested (E : Entity_Id) return Boolean is Scop : Entity_Id := Scope (E); begin while Scop /= Standard_Standard loop if Ekind (Scop) in Subprogram_Kind then return True; elsif Ekind (Scop) = E_Task_Type or else Ekind (Scop) = E_Entry or else Ekind (Scop) = E_Entry_Family then return True; end if; Scop := Scope (Scop); end loop; return False; end Is_Nested; ---------- -- Lock -- ---------- procedure Lock is begin Pending_Instantiations.Locked := True; Inlined_Bodies.Locked := True; Successors.Locked := True; Inlined.Locked := True; Pending_Instantiations.Release; Inlined_Bodies.Release; Successors.Release; Inlined.Release; end Lock; -------------------------- -- Remove_Dead_Instance -- -------------------------- procedure Remove_Dead_Instance (N : Node_Id) is J : Int; begin J := 0; while J <= Pending_Instantiations.Last loop if Pending_Instantiations.Table (J).Inst_Node = N then Pending_Instantiations.Table (J).Inst_Node := Empty; return; end if; J := J + 1; end loop; end Remove_Dead_Instance; ------------------------ -- Scope_In_Main_Unit -- ------------------------ function Scope_In_Main_Unit (Scop : Entity_Id) return Boolean is Comp : Node_Id; S : Entity_Id := Scop; Ent : Entity_Id := Cunit_Entity (Main_Unit); begin -- The scope may be within the main unit, or it may be an ancestor -- of the main unit, if the main unit is a child unit. In both cases -- it makes no sense to process the body before the main unit. In -- the second case, this may lead to circularities if a parent body -- depends on a child spec, and we are analyzing the child. while Scope (S) /= Standard_Standard and then not Is_Child_Unit (S) loop S := Scope (S); end loop; Comp := Parent (S); while Present (Comp) and then Nkind (Comp) /= N_Compilation_Unit loop Comp := Parent (Comp); end loop; if Is_Child_Unit (Ent) then while Present (Ent) and then Is_Child_Unit (Ent) loop if Scope (Ent) = S then return True; end if; Ent := Scope (Ent); end loop; end if; return Comp = Cunit (Main_Unit) or else Comp = Library_Unit (Cunit (Main_Unit)); end Scope_In_Main_Unit; end Inline;