X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fada%2Fsem_elab.adb;h=1e278a6bb58c7c6b1cadf9c7128a65d629c3de89;hb=2a62ce00f61d26370c9b174c98dbd2f5136082bd;hp=9efa7ca022cecee112d7365edcbfb484ee08414f;hpb=da253936ab1342aaac88586a88a2861ca092aba2;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/ada/sem_elab.adb b/gcc/ada/sem_elab.adb index 9efa7ca022c..1e278a6bb58 100644 --- a/gcc/ada/sem_elab.adb +++ b/gcc/ada/sem_elab.adb @@ -6,23 +6,20 @@ -- -- -- B o d y -- -- -- --- $Revision: 1.3 $ --- -- --- Copyright (C) 1997-2001 Free Software Foundation, Inc. -- +-- Copyright (C) 1997-2009, 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- -- +-- ware Foundation; either version 3, 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. -- +-- Public License distributed with GNAT; see file COPYING3. If not, go to -- +-- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- --- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ @@ -32,6 +29,7 @@ with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; +with Exp_Tss; use Exp_Tss; with Exp_Util; use Exp_Util; with Expander; use Expander; with Fname; use Fname; @@ -43,11 +41,13 @@ with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; +with Rident; use Rident; with Sem; use Sem; with Sem_Cat; use Sem_Cat; with Sem_Ch7; use Sem_Ch7; with Sem_Ch8; use Sem_Ch8; with Sem_Res; use Sem_Res; +with Sem_Type; use Sem_Type; with Sem_Util; use Sem_Util; with Sinfo; use Sinfo; with Sinput; use Sinput; @@ -59,11 +59,11 @@ with Uname; use Uname; package body Sem_Elab is - -- The following table records the recursive call chain for output - -- in the Output routine. Each entry records the call node and the - -- entity of the called routine. The number of entries in the table - -- (i.e. the value of Elab_Call.Last) indicates the current depth - -- of recursion and is used to identify the outer level. + -- The following table records the recursive call chain for output in the + -- Output routine. Each entry records the call node and the entity of the + -- called routine. The number of entries in the table (i.e. the value of + -- Elab_Call.Last) indicates the current depth of recursion and is used to + -- identify the outer level. type Elab_Call_Entry is record Cloc : Source_Ptr; @@ -78,10 +78,10 @@ package body Sem_Elab is Table_Increment => 100, Table_Name => "Elab_Call"); - -- This table is initialized at the start of each outer level call. - -- It holds the entities for all subprograms that have been examined - -- for this particular outer level call, and is used to prevent both - -- infinite recursion, and useless reanalysis of bodies already seen + -- This table is initialized at the start of each outer level call. It + -- holds the entities for all subprograms that have been examined for this + -- particular outer level call, and is used to prevent both infinite + -- recursion, and useless reanalysis of bodies already seen package Elab_Visited is new Table.Table ( Table_Component_Type => Entity_Id, @@ -117,7 +117,6 @@ package body Sem_Elab is Outer_Scope : Entity_Id; -- Save scope of outer level call - end record; package Delay_Check is new Table.Table ( @@ -129,9 +128,8 @@ package body Sem_Elab is Table_Name => "Delay_Check"); C_Scope : Entity_Id; - -- Top level scope of current scope. We need to compute this only - -- once at the outer level, i.e. for a call to Check_Elab_Call from - -- outside this unit. + -- Top level scope of current scope. Compute this only once at the outer + -- level, i.e. for a call to Check_Elab_Call from outside this unit. Outer_Level_Sloc : Source_Ptr; -- Save Sloc value for outer level call node for comparisons of source @@ -151,37 +149,43 @@ package body Sem_Elab is Delaying_Elab_Checks : Boolean := True; -- This is set True till the compilation is complete, including the - -- insertion of all instance bodies. Then when Check_Elab_Calls is - -- called, the delay table is used to make the delayed calls and - -- this flag is reset to False, so that the calls are processed + -- insertion of all instance bodies. Then when Check_Elab_Calls is called, + -- the delay table is used to make the delayed calls and this flag is reset + -- to False, so that the calls are processed ----------------------- -- Local Subprograms -- ----------------------- - -- Note: Outer_Scope in all these calls represents the scope of + -- Note: Outer_Scope in all following specs represents the scope of -- interest of the outer level call. If it is set to Standard_Standard, -- then it means the outer level call was at elaboration level, and that -- thus all calls are of interest. If it was set to some other scope, -- then the original call was an inner call, and we are not interested -- in calls that go outside this scope. + procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id); + -- Analysis of construct N shows that we should set Elaborate_All_Desirable + -- for the WITH clause for unit U (which will always be present). A special + -- case is when N is a function or procedure instantiation, in which case + -- it is sufficient to set Elaborate_Desirable, since in this case there is + -- no possibility of transitive elaboration issues. + procedure Check_A_Call (N : Node_Id; E : Entity_Id; Outer_Scope : Entity_Id; Inter_Unit_Only : Boolean; Generate_Warnings : Boolean := True); - -- This is the internal recursive routine that is called to check for - -- a possible elaboration error. The argument N is a subprogram call - -- or generic instantiation to be checked, and E is the entity of - -- the called subprogram, or instantiated generic unit. The flag - -- Outer_Scope is the outer level scope for the original call. - -- Inter_Unit_Only is set if the call is only to be checked in the - -- case where it is to another unit (and skipped if within a unit). - -- Generate_Warnings is set to True to suppress warning messages - -- about missing pragma Elaborate_All's. These messages are not - -- wanted for inner calls in the dynamic model. + -- This is the internal recursive routine that is called to check for a + -- possible elaboration error. The argument N is a subprogram call or + -- generic instantiation to be checked, and E is the entity of the called + -- subprogram, or instantiated generic unit. The flag Outer_Scope is the + -- outer level scope for the original call. Inter_Unit_Only is set if the + -- call is only to be checked in the case where it is to another unit (and + -- skipped if within a unit). Generate_Warnings is set to False to suppress + -- warning messages about missing pragma Elaborate_All's. These messages + -- are not wanted for inner calls in the dynamic model. procedure Check_Bad_Instantiation (N : Node_Id); -- N is a node for an instantiation (if called with any other node kind, @@ -202,14 +206,14 @@ package body Sem_Elab is E : Entity_Id; Outer_Scope : Entity_Id; Orig_Ent : Entity_Id); - -- N is a function call or procedure statement call node and E is - -- the entity of the called function, which is within the current - -- compilation unit (where subunits count as part of the parent). - -- This call checks if this call, or any call within any accessed - -- body could cause an ABE, and if so, outputs a warning. Orig_Ent - -- differs from E only in the case of renamings, and points to the - -- original name of the entity. This is used for error messages. - -- Outer_Scope is the outer level scope for the original call. + -- N is a function call or procedure statement call node and E is the + -- entity of the called function, which is within the current compilation + -- unit (where subunits count as part of the parent). This call checks if + -- this call, or any call within any accessed body could cause an ABE, and + -- if so, outputs a warning. Orig_Ent differs from E only in the case of + -- renamings, and points to the original name of the entity. This is used + -- for error messages. Outer_Scope is the outer level scope for the + -- original call. procedure Check_Internal_Call_Continue (N : Node_Id; @@ -219,10 +223,33 @@ package body Sem_Elab is -- The processing for Check_Internal_Call is divided up into two phases, -- and this represents the second phase. The second phase is delayed if -- Delaying_Elab_Calls is set to True. In this delayed case, the first - -- phase makes an entry in the Delay_Check table, which is processed - -- when Check_Elab_Calls is called. N, E and Orig_Ent are as for the call - -- to Check_Internal_Call. Outer_Scope is the outer level scope for - -- the original call. + -- phase makes an entry in the Delay_Check table, which is processed when + -- Check_Elab_Calls is called. N, E and Orig_Ent are as for the call to + -- Check_Internal_Call. Outer_Scope is the outer level scope for the + -- original call. + + procedure Set_Elaboration_Constraint + (Call : Node_Id; + Subp : Entity_Id; + Scop : Entity_Id); + -- The current unit U may depend semantically on some unit P which is not + -- in the current context. If there is an elaboration call that reaches P, + -- we need to indicate that P requires an Elaborate_All, but this is not + -- effective in U's ali file, if there is no with_clause for P. In this + -- case we add the Elaborate_All on the unit Q that directly or indirectly + -- makes P available. This can happen in two cases: + -- + -- a) Q declares a subtype of a type declared in P, and the call is an + -- initialization call for an object of that subtype. + -- + -- b) Q declares an object of some tagged type whose root type is + -- declared in P, and the initialization call uses object notation on + -- that object to reach a primitive operation or a classwide operation + -- declared in P. + -- + -- If P appears in the context of U, the current processing is correct. + -- Otherwise we must identify these two cases to retrieve Q and place the + -- Elaborate_All_Desirable on it. function Has_Generic_Body (N : Node_Id) return Boolean; -- N is a generic package instantiation node, and this routine determines @@ -240,16 +267,16 @@ package body Sem_Elab is -- inevitable, given the optional body semantics of Ada). procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty); - -- Given code for an elaboration check (or unconditional raise if - -- the check is not needed), inserts the code in the appropriate - -- place. N is the call or instantiation node for which the check - -- code is required. C is the test whose failure triggers the raise. + -- Given code for an elaboration check (or unconditional raise if the check + -- is not needed), inserts the code in the appropriate place. N is the call + -- or instantiation node for which the check code is required. C is the + -- test whose failure triggers the raise. procedure Output_Calls (N : Node_Id); - -- Outputs chain of calls stored in the Elab_Call table. The caller - -- has already generated the main warning message, so the warnings - -- generated are all continuation messages. The argument is the - -- call node at which the messages are to be placed. + -- Outputs chain of calls stored in the Elab_Call table. The caller has + -- already generated the main warning message, so the warnings generated + -- are all continuation messages. The argument is the call node at which + -- the messages are to be placed. function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean; -- Given two scopes, determine whether they are the same scope from an @@ -260,24 +287,180 @@ package body Sem_Elab is -- to be the enclosing compilation unit of this scope. function Spec_Entity (E : Entity_Id) return Entity_Id; - -- Given a compilation unit entity, if it is a spec entity, it is - -- returned unchanged. If it is a body entity, then the spec for - -- the corresponding spec is returned + -- Given a compilation unit entity, if it is a spec entity, it is returned + -- unchanged. If it is a body entity, then the spec for the corresponding + -- spec is returned procedure Supply_Bodies (N : Node_Id); -- Given a node, N, that is either a subprogram declaration or a package -- declaration, this procedure supplies dummy bodies for the subprogram -- or for all subprograms in the package. If the given node is not one -- of these two possibilities, then Supply_Bodies does nothing. The - -- dummy body is supplied by setting the subprogram to be Imported with - -- convention Stubbed. + -- dummy body contains a single Raise statement. procedure Supply_Bodies (L : List_Id); - -- Calls Supply_Bodies for all elements of the given list L. + -- Calls Supply_Bodies for all elements of the given list L function Within (E1, E2 : Entity_Id) return Boolean; - -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or - -- is one of its contained scopes, False otherwise. + -- Given two scopes E1 and E2, returns True if E1 is equal to E2, or is one + -- of its contained scopes, False otherwise. + + function Within_Elaborate_All (E : Entity_Id) return Boolean; + -- Before emitting a warning on a scope E for a missing elaborate_all, + -- check whether E may be in the context of a directly visible unit U to + -- which the pragma applies. This prevents spurious warnings when the + -- called entity is renamed within U. + + -------------------------------------- + -- Activate_Elaborate_All_Desirable -- + -------------------------------------- + + procedure Activate_Elaborate_All_Desirable (N : Node_Id; U : Entity_Id) is + UN : constant Unit_Number_Type := Get_Code_Unit (N); + CU : constant Node_Id := Cunit (UN); + UE : constant Entity_Id := Cunit_Entity (UN); + Unm : constant Unit_Name_Type := Unit_Name (UN); + CI : constant List_Id := Context_Items (CU); + Itm : Node_Id; + Ent : Entity_Id; + + procedure Add_To_Context_And_Mark (Itm : Node_Id); + -- This procedure is called when the elaborate indication must be + -- applied to a unit not in the context of the referencing unit. The + -- unit gets added to the context as an implicit with. + + function In_Withs_Of (UEs : Entity_Id) return Boolean; + -- UEs is the spec entity of a unit. If the unit to be marked is + -- in the context item list of this unit spec, then the call returns + -- True and Itm is left set to point to the relevant N_With_Clause node. + + procedure Set_Elab_Flag (Itm : Node_Id); + -- Sets Elaborate_[All_]Desirable as appropriate on Itm + + ----------------------------- + -- Add_To_Context_And_Mark -- + ----------------------------- + + procedure Add_To_Context_And_Mark (Itm : Node_Id) is + CW : constant Node_Id := + Make_With_Clause (Sloc (Itm), + Name => Name (Itm)); + + begin + Set_Library_Unit (CW, Library_Unit (Itm)); + Set_Implicit_With (CW, True); + + -- Set elaborate all desirable on copy and then append the copy to + -- the list of body with's and we are done. + + Set_Elab_Flag (CW); + Append_To (CI, CW); + end Add_To_Context_And_Mark; + + ----------------- + -- In_Withs_Of -- + ----------------- + + function In_Withs_Of (UEs : Entity_Id) return Boolean is + UNs : constant Unit_Number_Type := Get_Source_Unit (UEs); + CUs : constant Node_Id := Cunit (UNs); + CIs : constant List_Id := Context_Items (CUs); + + begin + Itm := First (CIs); + while Present (Itm) loop + if Nkind (Itm) = N_With_Clause then + Ent := + Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); + + if U = Ent then + return True; + end if; + end if; + + Next (Itm); + end loop; + + return False; + end In_Withs_Of; + + ------------------- + -- Set_Elab_Flag -- + ------------------- + + procedure Set_Elab_Flag (Itm : Node_Id) is + begin + if Nkind (N) in N_Subprogram_Instantiation then + Set_Elaborate_Desirable (Itm); + else + Set_Elaborate_All_Desirable (Itm); + end if; + end Set_Elab_Flag; + + -- Start of processing for Activate_Elaborate_All_Desirable + + begin + -- Do not set binder indication if expansion is disabled, as when + -- compiling a generic unit. + + if not Expander_Active then + return; + end if; + + Itm := First (CI); + while Present (Itm) loop + if Nkind (Itm) = N_With_Clause then + Ent := Cunit_Entity (Get_Cunit_Unit_Number (Library_Unit (Itm))); + + -- If we find it, then mark elaborate all desirable and return + + if U = Ent then + Set_Elab_Flag (Itm); + return; + end if; + end if; + + Next (Itm); + end loop; + + -- If we fall through then the with clause is not present in the + -- current unit. One legitimate possibility is that the with clause + -- is present in the spec when we are a body. + + if Is_Body_Name (Unm) + and then In_Withs_Of (Spec_Entity (UE)) + then + Add_To_Context_And_Mark (Itm); + return; + end if; + + -- Similarly, we may be in the spec or body of a child unit, where + -- the unit in question is with'ed by some ancestor of the child unit. + + if Is_Child_Name (Unm) then + declare + Pkg : Entity_Id; + + begin + Pkg := UE; + loop + Pkg := Scope (Pkg); + exit when Pkg = Standard_Standard; + + if In_Withs_Of (Pkg) then + Add_To_Context_And_Mark (Itm); + return; + end if; + end loop; + end; + end if; + + -- Here if we do not find with clause on spec or body. We just ignore + -- this case, it means that the elaboration involves some other unit + -- than the unit being compiled, and will be caught elsewhere. + + null; + end Activate_Elaborate_All_Desirable; ------------------ -- Check_A_Call -- @@ -295,7 +478,22 @@ package body Sem_Elab is Decl : Node_Id; E_Scope : Entity_Id; - -- Top level scope of entity for called subprogram + -- Top level scope of entity for called subprogram. This value includes + -- following renamings and derivations, so this scope can be in a + -- non-visible unit. This is the scope that is to be investigated to + -- see whether an elaboration check is required. + + W_Scope : Entity_Id; + -- Top level scope of directly called entity for subprogram. This + -- differs from E_Scope in the case where renamings or derivations + -- are involved, since it does not follow these links. W_Scope is + -- generally in a visible unit, and it is this scope that may require + -- an Elaborate_All. However, there are some cases (initialization + -- calls and calls involving object notation) where W_Scope might not + -- be in the context of the current unit, and there is an intermediate + -- package that is, in which case the Elaborate_All has to be placed + -- on this intermediate package. These special cases are handled in + -- Set_Elaboration_Constraint. Body_Acts_As_Spec : Boolean; -- Set to true if call is to body acting as spec (no separate spec) @@ -312,27 +510,37 @@ package body Sem_Elab is Unit_Caller : Unit_Number_Type; Unit_Callee : Unit_Number_Type; - Cunit_SW : Boolean := False; - -- Set to suppress warnings for case of external reference where - -- one of the enclosing scopes has the Suppress_Elaboration_Warnings - -- flag set. For the internal case, we ignore this flag. - Cunit_SC : Boolean := False; -- Set to suppress dynamic elaboration checks where one of the - -- enclosing scopes has Suppress_Elaboration_Checks set. For - -- the internal case, we ignore this flag. + -- enclosing scopes has Elaboration_Checks_Suppressed set, or else + -- if a pragma Elaborate (_All) applies to that scope, in which case + -- warnings on the scope are also suppressed. For the internal case, + -- we ignore this flag. begin - -- Go to parent for derived subprogram, or to original subprogram - -- in the case of a renaming (Alias covers both these cases) + -- If the call is known to be within a local Suppress Elaboration + -- pragma, nothing to check. This can happen in task bodies. + + if (Nkind (N) = N_Function_Call + or else Nkind (N) = N_Procedure_Call_Statement) + and then No_Elaboration_Check (N) + then + return; + end if; + + -- Go to parent for derived subprogram, or to original subprogram in the + -- case of a renaming (Alias covers both these cases). Ent := E; loop - if Suppress_Elaboration_Warnings (Ent) then + if (Suppress_Elaboration_Warnings (Ent) + or else Elaboration_Checks_Suppressed (Ent)) + and then (Inst_Case or else No (Alias (Ent))) + then return; end if; - -- Nothing to do for imported entities, + -- Nothing to do for imported entities if Is_Imported (Ent) then return; @@ -364,11 +572,9 @@ package body Sem_Elab is E_Scope := Ent; loop - if Suppress_Elaboration_Warnings (E_Scope) then - Cunit_SW := True; - end if; - - if Suppress_Elaboration_Checks (E_Scope) then + if Elaboration_Checks_Suppressed (E_Scope) + or else Suppress_Elaboration_Warnings (E_Scope) + then Cunit_SC := True; end if; @@ -401,8 +607,8 @@ package body Sem_Elab is -- If the generic entity is within a deeper instance than we are, then -- either the instantiation to which we refer itself caused an ABE, in - -- which case that will be handled separately. Otherwise, we know that - -- the body we need appears as needed at the point of the instantiation. + -- which case that will be handled separately, or else we know that the + -- body we need appears as needed at the point of the instantiation. -- However, this assumption is only valid if we are in static mode. if not Dynamic_Elaboration_Checks @@ -431,24 +637,50 @@ package body Sem_Elab is return; end if; - -- Nothing to do if some scope said to ignore warnings + -- Nothing to do if some scope said that no checks were required - if Cunit_SW then + if Cunit_SC then return; end if; - -- Nothing to do for a generic instance, because in this case - -- the checking was at the point of instantiation of the generic - -- However, this shortcut is only applicable in static mode. + -- Nothing to do for a generic instance, because in this case the + -- checking was at the point of instantiation of the generic However, + -- this shortcut is only applicable in static mode. if Is_Generic_Instance (Ent) and not Dynamic_Elaboration_Checks then return; end if; - -- Nothing to do if subprogram with no separate spec + -- Nothing to do if subprogram with no separate spec. However, a + -- call to Deep_Initialize may result in a call to a user-defined + -- Initialize procedure, which imposes a body dependency. This + -- happens only if the type is controlled and the Initialize + -- procedure is not inherited. if Body_Acts_As_Spec then - return; + if Is_TSS (Ent, TSS_Deep_Initialize) then + declare + Typ : Entity_Id; + Init : Entity_Id; + begin + Typ := Etype (Next_Formal (First_Formal (Ent))); + + if not Is_Controlled (Typ) then + return; + else + Init := Find_Prim_Op (Typ, Name_Initialize); + + if Comes_From_Source (Init) then + Ent := Init; + else + return; + end if; + end if; + end; + + else + return; + end if; end if; -- Check cases of internal units @@ -491,7 +723,9 @@ package body Sem_Elab is return; end if; - Ent := E; + if Is_TSS (E, TSS_Deep_Initialize) then + Ent := E; + end if; -- If the call is in an instance, and the called entity is not -- defined in the same instance, then the elaboration issue @@ -521,13 +755,12 @@ package body Sem_Elab is if Unit_Caller /= No_Unit and then Unit_Callee /= Unit_Caller - and then Unit_Callee /= No_Unit and then not Dynamic_Elaboration_Checks then E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller)); - -- If we don't get a spec entity, just ignore call. Not - -- quite clear why this check is necessary. + -- If we don't get a spec entity, just ignore call. Not quite + -- clear why this check is necessary. ??? if No (E_Scope) then return; @@ -539,16 +772,15 @@ package body Sem_Elab is E_Scope := Scope (E_Scope); end loop; - -- For the case of not in an instance, or call within instance - -- We recompute E_Scope for the error message, since we - -- do NOT want to go to the unit which has the ultimate - -- declaration in the case of renaming and derivation and - -- we also want to go to the generic unit in the case of - -- an instance, and no further. + -- For the case N is not an instance, or a call within instance, we + -- recompute E_Scope for the error message, since we do NOT want to + -- go to the unit which has the ultimate declaration in the case of + -- renaming and derivation and we also want to go to the generic unit + -- in the case of an instance, and no further. else - -- Loop to carefully follow renamings and derivations - -- one step outside the current unit, but not further. + -- Loop to carefully follow renamings and derivations one step + -- outside the current unit, but not further. if not Inst_Case and then Present (Alias (Ent)) @@ -570,36 +802,122 @@ package body Sem_Elab is exit when E_Scope /= C_Scope; Ent := Alias (Ent); E_Scope := Ent; + + -- If no alias, there is a previous error + + if No (Ent) then + return; + end if; end loop; end if; + if Within_Elaborate_All (E_Scope) then + return; + end if; + + -- Find top level scope for called entity (not following renamings + -- or derivations). This is where the Elaborate_All will go if it + -- is needed. We start with the called entity, except in the case + -- of an initialization procedure outside the current package, where + -- the init proc is in the root package, and we start from the entity + -- of the name in the call. + + if Is_Entity_Name (Name (N)) + and then Is_Init_Proc (Entity (Name (N))) + and then not In_Same_Extended_Unit (N, Entity (Name (N))) + then + W_Scope := Scope (Entity (Name (N))); + else + W_Scope := E; + end if; + + while not Is_Compilation_Unit (W_Scope) loop + W_Scope := Scope (W_Scope); + end loop; + + -- Now check if an elaborate_all (or dynamic check) is needed + if not Suppress_Elaboration_Warnings (Ent) + and then not Elaboration_Checks_Suppressed (Ent) and then not Suppress_Elaboration_Warnings (E_Scope) + and then not Elaboration_Checks_Suppressed (E_Scope) and then Elab_Warnings and then Generate_Warnings then - Warn_On_Instance := True; + Generate_Elab_Warnings : declare + procedure Elab_Warning + (Msg_D : String; + Msg_S : String; + Ent : Node_Or_Entity_Id); + -- Generate a call to Error_Msg_NE with parameters Msg_D or + -- Msg_S (for dynamic or static elaboration model), N and Ent. + + ------------------ + -- Elab_Warning -- + ------------------ + + procedure Elab_Warning + (Msg_D : String; + Msg_S : String; + Ent : Node_Or_Entity_Id) + is + begin + if Dynamic_Elaboration_Checks then + Error_Msg_NE (Msg_D, N, Ent); + else + Error_Msg_NE (Msg_S, N, Ent); + end if; + end Elab_Warning; - if Inst_Case then - Error_Msg_NE - ("instantiation of& may raise Program_Error?", N, Ent); - else - Error_Msg_NE - ("call to & may raise Program_Error?", N, Ent); - end if; + -- Start of processing for Generate_Elab_Warnings + + begin + if Inst_Case then + Elab_Warning + ("instantiation of& may raise Program_Error?", + "info: instantiation of& during elaboration?", Ent); + + else + if Nkind (Name (N)) in N_Has_Entity + and then Is_Init_Proc (Entity (Name (N))) + and then Comes_From_Source (Ent) + then + Elab_Warning + ("implicit call to & may raise Program_Error?", + "info: implicit call to & during elaboration?", + Ent); + + else + Elab_Warning + ("call to & may raise Program_Error?", + "info: call to & during elaboration?", + Ent); + end if; + end if; + + Error_Msg_Qual_Level := Nat'Last; + + if Nkind (N) in N_Subprogram_Instantiation then + Elab_Warning + ("\missing pragma Elaborate for&?", + "\info: implicit pragma Elaborate for& generated?", + W_Scope); + else + Elab_Warning + ("\missing pragma Elaborate_All for&?", + "\info: implicit pragma Elaborate_All for & generated?", + W_Scope); + end if; + end Generate_Elab_Warnings; - Error_Msg_Qual_Level := Nat'Last; - Error_Msg_NE - ("\missing pragma Elaborate_All for&?", N, E_Scope); Error_Msg_Qual_Level := 0; Output_Calls (N); - Warn_On_Instance := False; - -- Set flag to prevent further warnings for same unit - -- unless in All_Errors_Mode. + -- Set flag to prevent further warnings for same unit unless in + -- All_Errors_Mode. if not All_Errors_Mode and not Dynamic_Elaboration_Checks then - Set_Suppress_Elaboration_Warnings (E_Scope); + Set_Suppress_Elaboration_Warnings (W_Scope, True); end if; end if; @@ -607,37 +925,58 @@ package body Sem_Elab is if Dynamic_Elaboration_Checks then if not Elaboration_Checks_Suppressed (Ent) - and then not Suppress_Elaboration_Checks (E_Scope) + and then not Elaboration_Checks_Suppressed (W_Scope) + and then not Elaboration_Checks_Suppressed (E_Scope) and then not Cunit_SC then - -- Runtime elaboration check required. generate check of the + -- Runtime elaboration check required. Generate check of the -- elaboration Boolean for the unit containing the entity. + -- Note that for this case, we do check the real unit (the one + -- from following renamings, since that is the issue!) + + -- Could this possibly miss a useless but required PE??? + Insert_Elab_Check (N, Make_Attribute_Reference (Loc, Attribute_Name => Name_Elaborated, - Prefix => - New_Occurrence_Of - (Spec_Entity (E_Scope), Loc))); + Prefix => New_Occurrence_Of (Spec_Entity (E_Scope), Loc))); end if; - -- If no dynamic check required, then ask binder to guarantee - -- that the necessary elaborations will be done properly! + -- Case of static elaboration model else - if not Suppress_Elaboration_Warnings (E) - and then not Suppress_Elaboration_Warnings (E_Scope) - and then Elab_Warnings - and then Generate_Warnings - and then not Inst_Case + -- Do not do anything if elaboration checks suppressed. Note that + -- we check Ent here, not E, since we want the real entity for the + -- body to see if checks are suppressed for it, not the dummy + -- entry for renamings or derivations. + + if Elaboration_Checks_Suppressed (Ent) + or else Elaboration_Checks_Suppressed (E_Scope) + or else Elaboration_Checks_Suppressed (W_Scope) then - Error_Msg_Node_2 := E_Scope; - Error_Msg_NE ("call to& in elaboration code " & - "requires pragma Elaborate_All on&?", N, E); - end if; + null; + + -- Here we need to generate an implicit elaborate all + + else + -- Generate elaborate_all warning unless suppressed + + if (Elab_Warnings and Generate_Warnings and not Inst_Case) + and then not Suppress_Elaboration_Warnings (Ent) + and then not Suppress_Elaboration_Warnings (E_Scope) + and then not Suppress_Elaboration_Warnings (W_Scope) + then + Error_Msg_Node_2 := W_Scope; + Error_Msg_NE + ("call to& in elaboration code " & + "requires pragma Elaborate_All on&?", N, E); + end if; + + -- Set indication for binder to generate Elaborate_All - Set_Elaborate_All_Desirable (E_Scope); - Set_Suppress_Elaboration_Warnings (E_Scope); + Set_Elaboration_Constraint (N, E, W_Scope); + end if; end if; -- Case of entity is in same unit as call or instantiation @@ -645,7 +984,6 @@ package body Sem_Elab is elsif not Inter_Unit_Only then Check_Internal_Call (N, Ent, Outer_Scope, E); end if; - end Check_A_Call; ----------------------------- @@ -653,7 +991,6 @@ package body Sem_Elab is ----------------------------- procedure Check_Bad_Instantiation (N : Node_Id) is - Nam : Node_Id; Ent : Entity_Id; begin @@ -663,9 +1000,9 @@ package body Sem_Elab is if Nkind (N) not in N_Generic_Instantiation then return; - -- Nothing to do if errors already detected (avoid cascaded errors) + -- Nothing to do if serious errors detected (avoid cascaded errors) - elsif Errors_Detected /= 0 then + elsif Serious_Errors_Detected /= 0 then return; -- Nothing to do if not in full analysis mode @@ -692,14 +1029,13 @@ package body Sem_Elab is return; end if; - Nam := Name (N); - Ent := Entity (Nam); + Ent := Get_Generic_Entity (N); -- The case we are interested in is when the generic spec is in the -- current declarative part if not Same_Elaboration_Scope (Current_Scope, Scope (Ent)) - or else not In_Same_Extended_Unit (Sloc (N), Sloc (Ent)) + or else not In_Same_Extended_Unit (N, Ent) then return; end if; @@ -753,7 +1089,6 @@ package body Sem_Elab is ("\?Program_Error will be raised at run time", N); Insert_Elab_Check (N); Set_ABE_Is_Certain (N); - end Check_Bad_Instantiation; --------------------- @@ -764,11 +1099,50 @@ package body Sem_Elab is (N : Node_Id; Outer_Scope : Entity_Id := Empty) is - Nam : Node_Id; Ent : Entity_Id; P : Node_Id; + function Get_Called_Ent return Entity_Id; + -- Retrieve called entity. If this is a call to a protected subprogram, + -- entity is a selected component. The callable entity may be absent, + -- in which case there is no check to perform. This happens with + -- non-analyzed calls in nested generics. + + -------------------- + -- Get_Called_Ent -- + -------------------- + + function Get_Called_Ent return Entity_Id is + Nam : Node_Id; + + begin + Nam := Name (N); + + if No (Nam) then + return Empty; + + elsif Nkind (Nam) = N_Selected_Component then + return Entity (Selector_Name (Nam)); + + elsif not Is_Entity_Name (Nam) then + return Empty; + + else + return Entity (Nam); + end if; + end Get_Called_Ent; + + -- Start of processing for Check_Elab_Call + begin + -- If the call does not come from the main unit, there is nothing to + -- check. Elaboration call from units in the context of the main unit + -- will lead to semantic dependencies when those units are compiled. + + if not In_Extended_Main_Code_Unit (N) then + return; + end if; + -- For an entry call, check relevant restriction if Nkind (N) = N_Entry_Call_Statement @@ -784,7 +1158,7 @@ package body Sem_Elab is then return; - -- Nothing to do if this is a call already rewritten for elab checking. + -- Nothing to do if this is a call already rewritten for elab checking elsif Nkind (Parent (N)) = N_Conditional_Expression then return; @@ -792,7 +1166,7 @@ package body Sem_Elab is -- Nothing to do if inside a generic template elsif Inside_A_Generic - and then not Present (Enclosing_Generic_Body (N)) + and then No (Enclosing_Generic_Body (N)) then return; end if; @@ -815,13 +1189,15 @@ package body Sem_Elab is Write_Eol; end if; - -- Climb up the tree to make sure we are not inside a - -- default expression of a parameter specification or - -- a record component, since in both these cases, we - -- will be doing the actual call later, not now, and it - -- is at the time of the actual call (statically speaking) - -- that we must do our static check, not at the time of - -- its initial analysis). + -- Climb up the tree to make sure we are not inside default expression + -- of a parameter specification or a record component, since in both + -- these cases, we will be doing the actual call later, not now, and it + -- is at the time of the actual call (statically speaking) that we must + -- do our static check, not at the time of its initial analysis). + + -- However, we have to check calls within component definitions (e.g. + -- a function call that determines an array component bound), so we + -- terminate the loop in that case. P := Parent (N); while Present (P) loop @@ -830,6 +1206,13 @@ package body Sem_Elab is Nkind (P) = N_Component_Declaration then return; + + -- The call occurs within the constraint of a component, + -- so it must be checked. + + elsif Nkind (P) = N_Component_Definition then + exit; + else P := Parent (P); end if; @@ -840,8 +1223,8 @@ package body Sem_Elab is if No (Outer_Scope) then Elab_Visited.Set_Last (0); - -- Nothing to do if current scope is Standard (this is a bit - -- odd, but it happens in the case of generic instantiations). + -- Nothing to do if current scope is Standard (this is a bit odd, but + -- it happens in the case of generic instantiations). C_Scope := Current_Scope; @@ -852,36 +1235,38 @@ package body Sem_Elab is -- First case, we are in elaboration code From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; - if From_Elab_Code then - -- Complain if call that comes from source in preelaborated - -- unit and we are not inside a subprogram (i.e. we are in - -- elab code) + -- Complain if call that comes from source in preelaborated unit + -- and we are not inside a subprogram (i.e. we are in elab code). if Comes_From_Source (N) and then In_Preelaborated_Unit + and then not In_Inlined_Body then + -- This is a warning in GNAT mode allowing such calls to be + -- used in the predefined library with appropriate care. + + Error_Msg_Warn := GNAT_Mode; Error_Msg_N - ("non-static call not allowed in preelaborated unit", N); + (" True, Generate_Warnings => False); + -- Otherwise nothing to do + else return; end if; + + -- A call to an Init_Proc in elaboration code may bring additional + -- dependencies, if some of the record components thereof have + -- initializations that are function calls that come from source. We + -- treat the current node as a call to each of these functions, to check + -- their elaboration impact. + + if Is_Init_Proc (Ent) + and then From_Elab_Code + then + Process_Init_Proc : declare + Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent); + + function Check_Init_Call (Nod : Node_Id) return Traverse_Result; + -- Find subprogram calls within body of Init_Proc for Traverse + -- instantiation below. + + procedure Traverse_Body is new Traverse_Proc (Check_Init_Call); + -- Traversal procedure to find all calls with body of Init_Proc + + --------------------- + -- Check_Init_Call -- + --------------------- + + function Check_Init_Call (Nod : Node_Id) return Traverse_Result is + Func : Entity_Id; + + begin + if (Nkind (Nod) = N_Function_Call + or else Nkind (Nod) = N_Procedure_Call_Statement) + and then Is_Entity_Name (Name (Nod)) + then + Func := Entity (Name (Nod)); + + if Comes_From_Source (Func) then + Check_A_Call + (N, Func, Standard_Standard, Inter_Unit_Only => True); + end if; + + return OK; + + else + return OK; + end if; + end Check_Init_Call; + + -- Start of processing for Process_Init_Proc + + begin + if Nkind (Unit_Decl) = N_Subprogram_Body then + Traverse_Body (Handled_Statement_Sequence (Unit_Decl)); + end if; + end Process_Init_Proc; + end if; end Check_Elab_Call; + ----------------------- + -- Check_Elab_Assign -- + ----------------------- + + procedure Check_Elab_Assign (N : Node_Id) is + Ent : Entity_Id; + Scop : Entity_Id; + + Pkg_Spec : Entity_Id; + Pkg_Body : Entity_Id; + + begin + -- For record or array component, check prefix. If it is an access type, + -- then there is nothing to do (we do not know what is being assigned), + -- but otherwise this is an assignment to the prefix. + + if Nkind (N) = N_Indexed_Component + or else + Nkind (N) = N_Selected_Component + or else + Nkind (N) = N_Slice + then + if not Is_Access_Type (Etype (Prefix (N))) then + Check_Elab_Assign (Prefix (N)); + end if; + + return; + end if; + + -- For type conversion, check expression + + if Nkind (N) = N_Type_Conversion then + Check_Elab_Assign (Expression (N)); + return; + end if; + + -- Nothing to do if this is not an entity reference otherwise get entity + + if Is_Entity_Name (N) then + Ent := Entity (N); + else + return; + end if; + + -- What we are looking for is a reference in the body of a package that + -- modifies a variable declared in the visible part of the package spec. + + if Present (Ent) + and then Comes_From_Source (N) + and then not Suppress_Elaboration_Warnings (Ent) + and then Ekind (Ent) = E_Variable + and then not In_Private_Part (Ent) + and then Is_Library_Level_Entity (Ent) + then + Scop := Current_Scope; + loop + if No (Scop) or else Scop = Standard_Standard then + return; + elsif Ekind (Scop) = E_Package + and then Is_Compilation_Unit (Scop) + then + exit; + else + Scop := Scope (Scop); + end if; + end loop; + + -- Here Scop points to the containing library package + + Pkg_Spec := Scop; + Pkg_Body := Body_Entity (Pkg_Spec); + + -- All OK if the package has an Elaborate_Body pragma + + if Has_Pragma_Elaborate_Body (Scop) then + return; + end if; + + -- OK if entity being modified is not in containing package spec + + if not In_Same_Source_Unit (Scop, Ent) then + return; + end if; + + -- All OK if entity appears in generic package or generic instance. + -- We just get too messed up trying to give proper warnings in the + -- presence of generics. Better no message than a junk one. + + Scop := Scope (Ent); + while Present (Scop) and then Scop /= Pkg_Spec loop + if Ekind (Scop) = E_Generic_Package then + return; + elsif Ekind (Scop) = E_Package + and then Is_Generic_Instance (Scop) + then + return; + end if; + + Scop := Scope (Scop); + end loop; + + -- All OK if in task, don't issue warnings there + + if In_Task_Activation then + return; + end if; + + -- OK if no package body + + if No (Pkg_Body) then + return; + end if; + + -- OK if reference is not in package body + + if not In_Same_Source_Unit (Pkg_Body, N) then + return; + end if; + + -- OK if package body has no handled statement sequence + + declare + HSS : constant Node_Id := + Handled_Statement_Sequence (Declaration_Node (Pkg_Body)); + begin + if No (HSS) or else not Comes_From_Source (HSS) then + return; + end if; + end; + + -- We definitely have a case of a modification of an entity in + -- the package spec from the elaboration code of the package body. + -- We may not give the warning (because there are some additional + -- checks to avoid too many false positives), but it would be a good + -- idea for the binder to try to keep the body elaboration close to + -- the spec elaboration. + + Set_Elaborate_Body_Desirable (Pkg_Spec); + + -- All OK in gnat mode (we know what we are doing) + + if GNAT_Mode then + return; + end if; + + -- All OK if all warnings suppressed + + if Warning_Mode = Suppress then + return; + end if; + + -- All OK if elaboration checks suppressed for entity + + if Checks_May_Be_Suppressed (Ent) + and then Is_Check_Suppressed (Ent, Elaboration_Check) + then + return; + end if; + + -- OK if the entity is initialized. Note that the No_Initialization + -- flag usually means that the initialization has been rewritten into + -- assignments, but that still counts for us. + + declare + Decl : constant Node_Id := Declaration_Node (Ent); + begin + if Nkind (Decl) = N_Object_Declaration + and then (Present (Expression (Decl)) + or else No_Initialization (Decl)) + then + return; + end if; + end; + + -- Here is where we give the warning + + -- All OK if warnings suppressed on the entity + + if not Has_Warnings_Off (Ent) then + Error_Msg_Sloc := Sloc (Ent); + + Error_Msg_NE + ("?elaboration code may access& before it is initialized", + N, Ent); + Error_Msg_NE + ("\?suggest adding pragma Elaborate_Body to spec of &", + N, Scop); + Error_Msg_N + ("\?or an explicit initialization could be added #", N); + end if; + + if not All_Errors_Mode then + Set_Suppress_Elaboration_Warnings (Ent); + end if; + end if; + end Check_Elab_Assign; + ---------------------- -- Check_Elab_Calls -- ---------------------- procedure Check_Elab_Calls is begin - -- If expansion is disabled, do not generate any checks. Also - -- skip checks if any subunits are missing because in either - -- case we lack the full information that we need, and no object - -- file will be created in any case. - - if not Expander_Active or else Subunits_Missing then + -- If expansion is disabled, do not generate any checks. Also skip + -- checks if any subunits are missing because in either case we lack the + -- full information that we need, and no object file will be created in + -- any case. + + if not Expander_Active + or else Is_Generic_Unit (Cunit_Entity (Main_Unit)) + or else Subunits_Missing + then return; end if; -- Skip delayed calls if we had any errors - if Errors_Detected = 0 then + if Serious_Errors_Detected = 0 then Delaying_Elab_Checks := False; Expander_Mode_Save_And_Set (True); for J in Delay_Check.First .. Delay_Check.Last loop - New_Scope (Delay_Check.Table (J).Curscop); + Push_Scope (Delay_Check.Table (J).Curscop); From_Elab_Code := Delay_Check.Table (J).From_Elab_Code; Check_Internal_Call_Continue ( @@ -1102,8 +1751,7 @@ package body Sem_Elab is (N : Node_Id; Outer_Scope : Entity_Id := Empty) is - Nam : Node_Id; - Ent : Entity_Id; + Ent : Entity_Id; begin -- Check for and deal with bad instantiation case. There is some @@ -1128,8 +1776,13 @@ package body Sem_Elab is return; end if; - Nam := Name (N); - Ent := Entity (Nam); + -- Nothing to do if the instantiation is not in the main unit + + if not In_Extended_Main_Code_Unit (N) then + return; + end if; + + Ent := Get_Generic_Entity (N); From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit; -- See if we need to analyze this instantiation. We analyze it if @@ -1141,7 +1794,7 @@ package body Sem_Elab is -- outer level call. -- It is an outer level instantiation from elaboration code, or the - -- instantiated entity is in the same elaboratoin scope. + -- instantiated entity is in the same elaboration scope. -- And in these cases, we will check both the inter-unit case and -- the intra-unit (within a single unit) case. @@ -1162,11 +1815,11 @@ package body Sem_Elab is Set_C_Scope; Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False); - -- If none of those cases holds, but Dynamic_Elaboration_Checks mode - -- is set, then we will do the check, but only in the inter-unit case - -- (this is to accommodate unguarded elaboration calls from other units - -- in which this same mode is set). We inhibit warnings in this case, - -- since this instantiation is not occurring in elaboration code. + -- If none of those cases holds, but Dynamic_Elaboration_Checks mode is + -- set, then we will do the check, but only in the inter-unit case (this + -- is to accommodate unguarded elaboration calls from other units in + -- which this same mode is set). We inhibit warnings in this case, since + -- this instantiation is not occurring in elaboration code. elsif Dynamic_Elaboration_Checks then Set_C_Scope; @@ -1214,7 +1867,7 @@ package body Sem_Elab is -- Nothing to do if errors already detected (avoid cascaded errors) - elsif Errors_Detected /= 0 then + elsif Serious_Errors_Detected /= 0 then return; -- Nothing to do if not in full analysis mode @@ -1222,10 +1875,10 @@ package body Sem_Elab is elsif not Full_Analysis then return; - -- Nothing to do if within a default expression, since the call - -- is not actualy being made at this time. + -- Nothing to do if analyzing in special spec-expression mode, since the + -- call is not actually being made at this time. - elsif In_Default_Expression then + elsif In_Spec_Expression then return; -- Nothing to do for call to intrinsic subprogram @@ -1243,14 +1896,13 @@ package body Sem_Elab is -- Delay this call if we are still delaying calls if Delaying_Elab_Checks then - Delay_Check.Increment_Last; - Delay_Check.Table (Delay_Check.Last) := + Delay_Check.Append ( (N => N, E => E, Orig_Ent => Orig_Ent, Curscop => Current_Scope, Outer_Scope => Outer_Scope, - From_Elab_Code => From_Elab_Code); + From_Elab_Code => From_Elab_Code)); return; -- Otherwise, call phase 2 continuation right now @@ -1258,7 +1910,6 @@ package body Sem_Elab is else Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent); end if; - end Check_Internal_Call; ---------------------------------- @@ -1277,12 +1928,22 @@ package body Sem_Elab is Sbody : Node_Id; Ebody : Entity_Id; - function Process (N : Node_Id) return Traverse_Result; - -- Function applied to each node as we traverse the body. - -- Checks for call that needs checking, and if so checks - -- it. Always returns OK, so entire tree is traversed. + function Find_Elab_Reference (N : Node_Id) return Traverse_Result; + -- Function applied to each node as we traverse the body. Checks for + -- call or entity reference that needs checking, and if so checks it. + -- Always returns OK, so entire tree is traversed, except that as + -- described below subprogram bodies are skipped for now. + + procedure Traverse is new Atree.Traverse_Proc (Find_Elab_Reference); + -- Traverse procedure using above Find_Elab_Reference function + + ------------------------- + -- Find_Elab_Reference -- + ------------------------- + + function Find_Elab_Reference (N : Node_Id) return Traverse_Result is + Actual : Node_Id; - function Process (N : Node_Id) return Traverse_Result is begin -- If user has specified that there are no entry calls in elaboration -- code, do not trace past an accept statement, because the rendez- @@ -1290,16 +1951,31 @@ package body Sem_Elab is if (Nkind (Original_Node (N)) = N_Accept_Statement or else Nkind (Original_Node (N)) = N_Selective_Accept) - and then Restrictions (No_Entry_Calls_In_Elaboration_Code) + and then Restriction_Active (No_Entry_Calls_In_Elaboration_Code) then return Abandon; - -- If we have a subprogram call, check it + -- If we have a function call, check it - elsif Nkind (N) = N_Function_Call - or else Nkind (N) = N_Procedure_Call_Statement - then + elsif Nkind (N) = N_Function_Call then + Check_Elab_Call (N, Outer_Scope); + return OK; + + -- If we have a procedure call, check the call, and also check + -- arguments that are assignments (OUT or IN OUT mode formals). + + elsif Nkind (N) = N_Procedure_Call_Statement then Check_Elab_Call (N, Outer_Scope); + + Actual := First_Actual (N); + while Present (Actual) loop + if Known_To_Be_Assigned (Actual) then + Check_Elab_Assign (Actual); + end if; + + Next_Actual (Actual); + end loop; + return OK; -- If we have a generic instantiation, check it @@ -1308,29 +1984,32 @@ package body Sem_Elab is Check_Elab_Instantiation (N, Outer_Scope); return OK; - -- Skip subprogram bodies that come from source (wait for - -- call to analyze these). The reason for the come from - -- source test is to avoid catching task bodies. + -- Skip subprogram bodies that come from source (wait for call to + -- analyze these). The reason for the come from source test is to + -- avoid catching task bodies. - -- For task bodies, we should really avoid these too, waiting - -- for the task activation, but that's too much trouble to - -- catch for now, so we go in unconditionally. This is not - -- so terrible, it means the error backtrace is not quite - -- complete, and we are too eager to scan bodies of tasks - -- that are unused, but this is hardly very significant! + -- For task bodies, we should really avoid these too, waiting for the + -- task activation, but that's too much trouble to catch for now, so + -- we go in unconditionally. This is not so terrible, it means the + -- error backtrace is not quite complete, and we are too eager to + -- scan bodies of tasks that are unused, but this is hardly very + -- significant! elsif Nkind (N) = N_Subprogram_Body and then Comes_From_Source (N) then return Skip; + elsif Nkind (N) = N_Assignment_Statement + and then Comes_From_Source (N) + then + Check_Elab_Assign (Name (N)); + return OK; + else return OK; end if; - end Process; - - procedure Traverse is new Atree.Traverse_Proc; - -- Traverse procedure using above Process function + end Find_Elab_Reference; -- Start of processing for Check_Internal_Call_Continue @@ -1341,8 +2020,7 @@ package body Sem_Elab is Outer_Level_Sloc := Loc; end if; - Elab_Visited.Increment_Last; - Elab_Visited.Table (Elab_Visited.Last) := E; + Elab_Visited.Append (E); -- If the call is to a function that renames a literal, no check -- is needed. @@ -1366,8 +2044,8 @@ package body Sem_Elab is end if; end if; - -- If the body appears after the outer level call or - -- instantiation then we have an error case handled below. + -- If the body appears after the outer level call or instantiation then + -- we have an error case handled below. if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody)) and then not In_Task_Activation @@ -1380,15 +2058,13 @@ package body Sem_Elab is elsif Inst_Case then return; - -- Otherwise we have a call, so we trace through the called - -- body to see if it has any problems .. + -- Otherwise we have a call, so we trace through the called body to see + -- if it has any problems. else pragma Assert (Nkind (Sbody) = N_Subprogram_Body); - Elab_Call.Increment_Last; - Elab_Call.Table (Elab_Call.Last).Cloc := Loc; - Elab_Call.Table (Elab_Call.Last).Ent := E; + Elab_Call.Append ((Cloc => Loc, Ent => E)); if Debug_Flag_LL then Write_Str ("Elab_Call.Last = "); @@ -1400,14 +2076,14 @@ package body Sem_Elab is Write_Eol; end if; - -- Now traverse declarations and statements of subprogram body. - -- Note that we cannot simply Traverse (Sbody), since traverse - -- does not normally visit subprogram bodies. + -- Now traverse declarations and statements of subprogram body. Note + -- that we cannot simply Traverse (Sbody), since traverse does not + -- normally visit subprogram bodies. declare - Decl : Node_Id := First (Declarations (Sbody)); - + Decl : Node_Id; begin + Decl := First (Declarations (Sbody)); while Present (Decl) loop Traverse (Decl); Next (Decl); @@ -1420,16 +2096,13 @@ package body Sem_Elab is return; end if; - -- Here is the case of calling a subprogram where the body has - -- not yet been encountered, a warning message is needed. - - Warn_On_Instance := True; + -- Here is the case of calling a subprogram where the body has not yet + -- been encountered, a warning message is needed. - -- If we have nothing in the call stack, then this is at the - -- outer level, and the ABE is bound to occur. + -- If we have nothing in the call stack, then this is at the outer + -- level, and the ABE is bound to occur. if Elab_Call.Last = 0 then - if Inst_Case then Error_Msg_NE ("?cannot instantiate& before body seen", N, Orig_Ent); @@ -1466,7 +2139,7 @@ package body Sem_Elab is begin Set_Elaboration_Entity (E, Ent); - New_Scope (Scope (E)); + Push_Scope (Scope (E)); Insert_Action (Declaration_Node (E), Make_Object_Declaration (Loce, @@ -1479,6 +2152,15 @@ package body Sem_Elab is Set_Elaboration_Flag (Sbody, E); + -- Kill current value indication. This is necessary because + -- the tests of this flag are inserted out of sequence and + -- must not pick up bogus indications of the wrong constant + -- value. Also, this is never a true constant, since one way + -- or another, it gets reset. + + Set_Current_Value (Ent, Empty); + Set_Last_Assignment (Ent, Empty); + Set_Is_True_Constant (Ent, False); Pop_Scope; end; end if; @@ -1491,7 +2173,9 @@ package body Sem_Elab is -- Generate the warning - if not Suppress_Elaboration_Warnings (E) then + if not Suppress_Elaboration_Warnings (E) + and then not Elaboration_Checks_Suppressed (E) + then if Inst_Case then Error_Msg_NE ("instantiation of& may occur before body is seen?", @@ -1508,8 +2192,6 @@ package body Sem_Elab is end if; end if; - Warn_On_Instance := False; - -- Set flag to suppress further warnings on same subprogram -- unless in all errors mode @@ -1518,20 +2200,20 @@ package body Sem_Elab is end if; end Check_Internal_Call_Continue; - ---------------------------- - -- Check_Task_Activation -- - ---------------------------- + --------------------------- + -- Check_Task_Activation -- + --------------------------- procedure Check_Task_Activation (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); + Inter_Procs : constant Elist_Id := New_Elmt_List; + Intra_Procs : constant Elist_Id := New_Elmt_List; Ent : Entity_Id; P : Entity_Id; Task_Scope : Entity_Id; Cunit_SC : Boolean := False; Decl : Node_Id; Elmt : Elmt_Id; - Inter_Procs : Elist_Id := New_Elmt_List; - Intra_Procs : Elist_Id := New_Elmt_List; Enclosing : Entity_Id; procedure Add_Task_Proc (Typ : Entity_Id); @@ -1569,7 +2251,6 @@ package body Sem_Elab is and then Has_Task (Base_Type (Typ)) then Comp := First_Component (Typ); - while Present (Comp) loop Add_Task_Proc (Etype (Comp)); Comp := Next_Component (Comp); @@ -1584,6 +2265,13 @@ package body Sem_Elab is -- will have been elaborated already. We keep separate lists for -- each kind of task. + -- Skip this test if errors have occurred, since in this case + -- we can get false indications. + + if Serious_Errors_Detected /= 0 then + return; + end if; + if Present (Proc) then if Outer_Unit (Scope (Proc)) = Enclosing then @@ -1597,7 +2285,7 @@ package body Sem_Elab is ("task will be activated before elaboration of its body?", Decl); Error_Msg_N - ("Program_Error will be raised at run-time?", Decl); + ("\Program_Error will be raised at run-time?", Decl); elsif Present (Corresponding_Body (Unit_Declaration_Node (Proc))) @@ -1606,10 +2294,9 @@ package body Sem_Elab is end if; else - Elmt := First_Elmt (Inter_Procs); - - -- No need for multiple entries of the same type. + -- No need for multiple entries of the same type + Elmt := First_Elmt (Inter_Procs); while Present (Elmt) loop if Node (Elmt) = Proc then return; @@ -1631,9 +2318,7 @@ package body Sem_Elab is begin if Present (Decls) then Decl := First (Decls); - while Present (Decl) loop - if Nkind (Decl) = N_Object_Declaration and then Has_Task (Etype (Defining_Identifier (Decl))) then @@ -1650,11 +2335,12 @@ package body Sem_Elab is ---------------- function Outer_Unit (E : Entity_Id) return Entity_Id is - Outer : Entity_Id := E; + Outer : Entity_Id; begin + Outer := E; while Present (Outer) loop - if Suppress_Elaboration_Checks (Outer) then + if Elaboration_Checks_Suppressed (Outer) then Cunit_SC := True; end if; @@ -1672,7 +2358,7 @@ package body Sem_Elab is begin Enclosing := Outer_Unit (Current_Scope); - -- Find all tasks declared in the current unit. + -- Find all tasks declared in the current unit if Nkind (N) = N_Package_Body then P := Unit_Declaration_Node (Corresponding_Spec (N)); @@ -1692,6 +2378,7 @@ package body Sem_Elab is -- We only perform detailed checks in all tasks are library level -- entities. If the master is a subprogram or task, activation will -- depend on the activation of the master itself. + -- Should dynamic checks be added in the more general case??? if Ekind (Enclosing) /= E_Package then @@ -1702,7 +2389,6 @@ package body Sem_Elab is -- the task body to be elaborated before the current one. Elmt := First_Elmt (Inter_Procs); - while Present (Elmt) loop Ent := Node (Elmt); Task_Scope := Outer_Unit (Scope (Ent)); @@ -1710,38 +2396,42 @@ package body Sem_Elab is if not Is_Compilation_Unit (Task_Scope) then null; - elsif Suppress_Elaboration_Warnings (Task_Scope) then + elsif Suppress_Elaboration_Warnings (Task_Scope) + or else Elaboration_Checks_Suppressed (Task_Scope) + then null; elsif Dynamic_Elaboration_Checks then if not Elaboration_Checks_Suppressed (Ent) and then not Cunit_SC - and then not Restrictions (No_Entry_Calls_In_Elaboration_Code) + and then + not Restriction_Active (No_Entry_Calls_In_Elaboration_Code) then - -- Runtime elaboration check required. generate check of the + -- Runtime elaboration check required. Generate check of the -- elaboration Boolean for the unit containing the entity. Insert_Elab_Check (N, Make_Attribute_Reference (Loc, Attribute_Name => Name_Elaborated, Prefix => - New_Occurrence_Of - (Spec_Entity (Task_Scope), Loc))); + New_Occurrence_Of (Spec_Entity (Task_Scope), Loc))); end if; else - -- Force the binder to elaborate other unit first. + -- Force the binder to elaborate other unit first if not Suppress_Elaboration_Warnings (Ent) + and then not Elaboration_Checks_Suppressed (Ent) and then Elab_Warnings and then not Suppress_Elaboration_Warnings (Task_Scope) + and then not Elaboration_Checks_Suppressed (Task_Scope) then Error_Msg_Node_2 := Task_Scope; Error_Msg_NE ("activation of an instance of task type&" & " requires pragma Elaborate_All on &?", N, Ent); end if; - Set_Elaborate_All_Desirable (Task_Scope); + Activate_Elaborate_All_Desirable (N, Task_Scope); Set_Suppress_Elaboration_Warnings (Task_Scope); end if; @@ -1752,8 +2442,8 @@ package body Sem_Elab is -- the task procedure bodies, which are available. In_Task_Activation := True; - Elmt := First_Elmt (Intra_Procs); + Elmt := First_Elmt (Intra_Procs); while Present (Elmt) loop Ent := Node (Elmt); Check_Internal_Call_Continue (N, Ent, Enclosing, Ent); @@ -1763,41 +2453,129 @@ package body Sem_Elab is In_Task_Activation := False; end Check_Task_Activation; + -------------------------------- + -- Set_Elaboration_Constraint -- + -------------------------------- + + procedure Set_Elaboration_Constraint + (Call : Node_Id; + Subp : Entity_Id; + Scop : Entity_Id) + is + Elab_Unit : Entity_Id; + Init_Call : constant Boolean := + Chars (Subp) = Name_Initialize + and then Comes_From_Source (Subp) + and then Present (Parameter_Associations (Call)) + and then Is_Controlled (Etype (First_Actual (Call))); + begin + -- If the unit is mentioned in a with_clause of the current unit, it is + -- visible, and we can set the elaboration flag. + + if Is_Immediately_Visible (Scop) + or else (Is_Child_Unit (Scop) and then Is_Visible_Child_Unit (Scop)) + then + Activate_Elaborate_All_Desirable (Call, Scop); + Set_Suppress_Elaboration_Warnings (Scop, True); + return; + end if; + + -- If this is not an initialization call or a call using object notation + -- we know that the unit of the called entity is in the context, and + -- we can set the flag as well. The unit need not be visible if the call + -- occurs within an instantiation. + + if Is_Init_Proc (Subp) + or else Init_Call + or else Nkind (Original_Node (Call)) = N_Selected_Component + then + null; -- detailed processing follows. + + else + Activate_Elaborate_All_Desirable (Call, Scop); + Set_Suppress_Elaboration_Warnings (Scop, True); + return; + end if; + + -- If the unit is not in the context, there must be an intermediate unit + -- that is, on which we need to place to elaboration flag. This happens + -- with init proc calls. + + if Is_Init_Proc (Subp) + or else Init_Call + then + -- The initialization call is on an object whose type is not declared + -- in the same scope as the subprogram. The type of the object must + -- be a subtype of the type of operation. This object is the first + -- actual in the call. + + declare + Typ : constant Entity_Id := + Etype (First (Parameter_Associations (Call))); + begin + Elab_Unit := Scope (Typ); + while (Present (Elab_Unit)) + and then not Is_Compilation_Unit (Elab_Unit) + loop + Elab_Unit := Scope (Elab_Unit); + end loop; + end; + + -- If original node uses selected component notation, the prefix is + -- visible and determines the scope that must be elaborated. After + -- rewriting, the prefix is the first actual in the call. + + elsif Nkind (Original_Node (Call)) = N_Selected_Component then + Elab_Unit := Scope (Etype (First (Parameter_Associations (Call)))); + + -- Not one of special cases above + + else + -- Using previously computed scope. If the elaboration check is + -- done after analysis, the scope is not visible any longer, but + -- must still be in the context. + + Elab_Unit := Scop; + end if; + + Activate_Elaborate_All_Desirable (Call, Elab_Unit); + Set_Suppress_Elaboration_Warnings (Elab_Unit, True); + end Set_Elaboration_Constraint; + ---------------------- -- Has_Generic_Body -- ---------------------- function Has_Generic_Body (N : Node_Id) return Boolean is - Ent : constant Entity_Id := Entity (Name (N)); + Ent : constant Entity_Id := Get_Generic_Entity (N); Decl : constant Node_Id := Unit_Declaration_Node (Ent); Scop : Entity_Id; function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id; -- Determine if the list of nodes headed by N and linked by Next - -- contains a package body for the package spec entity E, and if - -- so return the package body. If not, then returns Empty. + -- contains a package body for the package spec entity E, and if so + -- return the package body. If not, then returns Empty. function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id; -- This procedure is called load the unit whose name is given by Nam. -- This unit is being loaded to see whether it contains an optional - -- generic body. The returned value is the loaded unit, which is - -- always a package body (only package bodies can contain other - -- entities in the sense in which Has_Generic_Body is interested). - -- We only attempt to load bodies if we are generating code. If we - -- are in semantics check only mode, then it would be wrong to load - -- bodies that are not required from a semantic point of view, so - -- in this case we return Empty. The result is that the caller may - -- incorrectly decide that a generic spec does not have a body when - -- in fact it does, but the only harm in this is that some warnings - -- on elaboration problems may be lost in semantic checks only mode, - -- which is not big loss. We also return Empty if we go for a body - -- and it is not there. + -- generic body. The returned value is the loaded unit, which is always + -- a package body (only package bodies can contain other entities in the + -- sense in which Has_Generic_Body is interested). We only attempt to + -- load bodies if we are generating code. If we are in semantics check + -- only mode, then it would be wrong to load bodies that are not + -- required from a semantic point of view, so in this case we return + -- Empty. The result is that the caller may incorrectly decide that a + -- generic spec does not have a body when in fact it does, but the only + -- harm in this is that some warnings on elaboration problems may be + -- lost in semantic checks only mode, which is not big loss. We also + -- return Empty if we go for a body and it is not there. function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id; -- PE is the entity for a package spec. This function locates the - -- corresponding package body, returning Empty if none is found. - -- The package body returned is fully parsed but may not yet be - -- analyzed, so only syntactic fields should be referenced. + -- corresponding package body, returning Empty if none is found. The + -- package body returned is fully parsed but may not yet be analyzed, + -- so only syntactic fields should be referenced. ------------------ -- Find_Body_In -- @@ -1879,17 +2657,17 @@ package body Sem_Elab is begin if Is_Library_Level_Entity (PE) then - -- If package is a library unit that requires a body, we have - -- no choice but to go after that body because it might contain - -- an optional body for the original generic package. + -- If package is a library unit that requires a body, we have no + -- choice but to go after that body because it might contain an + -- optional body for the original generic package. if Unit_Requires_Body (PE) then - -- Load the body. Note that we are a little careful here to - -- use Spec to get the unit number, rather than PE or Decl, - -- since in the case where the package is itself a library - -- level instantiation, Spec will properly reference the - -- generic template, which is what we really want. + -- Load the body. Note that we are a little careful here to use + -- Spec to get the unit number, rather than PE or Decl, since + -- in the case where the package is itself a library level + -- instantiation, Spec will properly reference the generic + -- template, which is what we really want. return Load_Package_Body @@ -1905,7 +2683,7 @@ package body Sem_Elab is -- Otherwise look and see if we are embedded in a further package - elsif Is_Package (Scop) then + elsif Is_Package_Or_Generic_Package (Scop) then -- If so, get the body of the enclosing package, and look in -- its package body for the package body we are looking for. @@ -1948,16 +2726,15 @@ package body Sem_Elab is -- Case of entity is in other than a package spec, in this case -- the body, if present, must be in the same declarative part. - if not Is_Package (Scop) then + if not Is_Package_Or_Generic_Package (Scop) then declare P : Node_Id; begin - P := Declaration_Node (Ent); - -- Declaration node may get us a spec, so if so, go to -- the parent declaration. + P := Declaration_Node (Ent); while not Is_List_Member (P) loop P := Parent (P); end loop; @@ -2025,9 +2802,14 @@ package body Sem_Elab is begin if No (C) then - R := Make_Raise_Program_Error (Loc); + R := + Make_Raise_Program_Error (Loc, + Reason => PE_Access_Before_Elaboration); else - R := Make_Raise_Program_Error (Loc, Make_Op_Not (Loc, C)); + R := + Make_Raise_Program_Error (Loc, + Condition => Make_Op_Not (Loc, C), + Reason => PE_Access_Before_Elaboration); end if; if No (Declarations (ADN)) then @@ -2047,18 +2829,29 @@ package body Sem_Elab is -- Unfortunately this does not work if the call has a dynamic size, -- because gigi regards it as a dynamic-sized temporary. If such a call -- appears in a short-circuit expression, the elaboration check will be - -- missed (rare enough ???). + -- missed (rare enough ???). Otherwise, the code below inserts the check + -- at the appropriate place before the call. Same applies in the even + -- rarer case the return type has a known size but is unconstrained. else if Nkind (N) = N_Function_Call and then Analyzed (Parent (N)) and then Size_Known_At_Compile_Time (Etype (N)) + and then + (not Has_Discriminants (Etype (N)) + or else Is_Constrained (Etype (N))) + then declare Typ : constant Entity_Id := Etype (N); - R : constant Node_Id := Make_Raise_Program_Error (Loc); Chk : constant Boolean := Do_Range_Check (N); + R : constant Node_Id := + Make_Raise_Program_Error (Loc, + Reason => PE_Access_Before_Elaboration); + + Reloc_N : Node_Id; + begin Set_Etype (R, Typ); @@ -2066,9 +2859,11 @@ package body Sem_Elab is Rewrite (N, R); else + Reloc_N := Relocate_Node (N); + Save_Interps (N, Reloc_N); Rewrite (N, Make_Conditional_Expression (Loc, - Expressions => New_List (C, Relocate_Node (N), R))); + Expressions => New_List (C, Reloc_N, R))); end if; Analyze_And_Resolve (N, Typ); @@ -2086,13 +2881,15 @@ package body Sem_Elab is else if No (C) then Insert_Action (Nod, - Make_Raise_Program_Error (Loc)); + Make_Raise_Program_Error (Loc, + Reason => PE_Access_Before_Elaboration)); else Insert_Action (Nod, Make_Raise_Program_Error (Loc, Condition => Make_Op_Not (Loc, - Right_Opnd => C))); + Right_Opnd => C), + Reason => PE_Access_Before_Elaboration)); end if; end if; end if; @@ -2136,7 +2933,7 @@ package body Sem_Elab is if Is_Generic_Unit (Ent) then Error_Msg_NE ("\?& instantiated #", N, Ent); - elsif Chars (Ent) = Name_uInit_Proc then + elsif Is_Init_Proc (Ent) then Error_Msg_N ("\?initialization procedure called #", N); elsif Is_Printable_Error_Name (Chars (Ent)) then @@ -2153,19 +2950,30 @@ package body Sem_Elab is ---------------------------- function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is - S1 : Entity_Id := Scop1; - S2 : Entity_Id := Scop2; + S1 : Entity_Id; + S2 : Entity_Id; begin + -- Find elaboration scope for Scop1 + -- This is either a subprogram or a compilation unit. + + S1 := Scop1; while S1 /= Standard_Standard + and then not Is_Compilation_Unit (S1) and then (Ekind (S1) = E_Package or else + Ekind (S1) = E_Protected_Type + or else Ekind (S1) = E_Block) loop S1 := Scope (S1); end loop; + -- Find elaboration scope for Scop2 + + S2 := Scop2; while S2 /= Standard_Standard + and then not Is_Compilation_Unit (S2) and then (Ekind (S2) = E_Package or else Ekind (S2) = E_Protected_Type @@ -2227,18 +3035,63 @@ package body Sem_Elab is if Nkind (N) = N_Subprogram_Declaration then declare Ent : constant Entity_Id := Defining_Unit_Name (Specification (N)); - begin - Set_Is_Imported (Ent); - Set_Convention (Ent, Convention_Stubbed); + + -- Internal subprograms will already have a generated body, so + -- there is no need to provide a stub for them. + + if No (Corresponding_Body (N)) then + declare + Loc : constant Source_Ptr := Sloc (N); + B : Node_Id; + Formals : constant List_Id := + Copy_Parameter_List (Ent); + Nam : constant Entity_Id := + Make_Defining_Identifier (Loc, Chars (Ent)); + Spec : Node_Id; + Stats : constant List_Id := + New_List + (Make_Raise_Program_Error (Loc, + Reason => PE_Access_Before_Elaboration)); + begin + if Ekind (Ent) = E_Function then + Spec := + Make_Function_Specification (Loc, + Defining_Unit_Name => Nam, + Parameter_Specifications => Formals, + Result_Definition => + New_Copy_Tree + (Result_Definition (Specification (N)))); + + -- We cannot reliably make a return statement for this + -- body, but none is needed because the call raises + -- program error. + + Set_Return_Present (Ent); + + else + Spec := + Make_Procedure_Specification (Loc, + Defining_Unit_Name => Nam, + Parameter_Specifications => Formals); + end if; + + B := Make_Subprogram_Body (Loc, + Specification => Spec, + Declarations => New_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Stats)); + Insert_After (N, B); + Analyze (B); + end; + end if; end; elsif Nkind (N) = N_Package_Declaration then declare Spec : constant Node_Id := Specification (N); - begin - New_Scope (Defining_Unit_Name (Spec)); + Push_Scope (Defining_Unit_Name (Spec)); Supply_Bodies (Visible_Declarations (Spec)); Supply_Bodies (Private_Declarations (Spec)); Pop_Scope; @@ -2248,7 +3101,6 @@ package body Sem_Elab is procedure Supply_Bodies (L : List_Id) is Elmt : Node_Id; - begin if Present (L) then Elmt := First (L); @@ -2265,23 +3117,63 @@ package body Sem_Elab is function Within (E1, E2 : Entity_Id) return Boolean is Scop : Entity_Id; - begin Scop := E1; - loop if Scop = E2 then return True; - elsif Scop = Standard_Standard then return False; - else Scop := Scope (Scop); end if; end loop; - - raise Program_Error; end Within; + -------------------------- + -- Within_Elaborate_All -- + -------------------------- + + function Within_Elaborate_All (E : Entity_Id) return Boolean is + Item : Node_Id; + Item2 : Node_Id; + Elab_Id : Entity_Id; + Par : Node_Id; + + begin + Item := First (Context_Items (Cunit (Current_Sem_Unit))); + while Present (Item) loop + if Nkind (Item) = N_Pragma + and then Pragma_Name (Item) = Name_Elaborate_All + then + -- Return if some previous error on the pragma itself + + if Error_Posted (Item) then + return False; + end if; + + Elab_Id := + Entity + (Expression (First (Pragma_Argument_Associations (Item)))); + + Par := Parent (Unit_Declaration_Node (Elab_Id)); + + Item2 := First (Context_Items (Par)); + while Present (Item2) loop + if Nkind (Item2) = N_With_Clause + and then Entity (Name (Item2)) = E + then + return True; + end if; + + Next (Item2); + end loop; + end if; + + Next (Item); + end loop; + + return False; + end Within_Elaborate_All; + end Sem_Elab;