-- Semantic analysis. -- Copyright (C) 2002, 2003, 2004, 2005 Tristan Gingold -- -- GHDL is free software; you can redistribute it and/or modify it under -- the terms of the GNU General Public License as published by the Free -- Software Foundation; either version 2, or (at your option) any later -- version. -- -- GHDL is distributed in the hope that it will be useful, but WITHOUT 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 -- along with GHDL; see the file COPYING. If not, write to the Free -- Software Foundation, 59 Temple Place - Suite 330, Boston, MA -- 02111-1307, USA. with Errorout; use Errorout; with Types; use Types; with Flags; use Flags; with Sem_Specs; use Sem_Specs; with Std_Package; use Std_Package; with Sem; use Sem; with Sem_Decls; use Sem_Decls; with Sem_Expr; use Sem_Expr; with Sem_Names; use Sem_Names; with Sem_Scopes; use Sem_Scopes; with Sem_Types; with Sem_Psl; with Std_Names; with Evaluation; use Evaluation; with Iirs_Utils; use Iirs_Utils; with Xrefs; use Xrefs; package body Sem_Stmts is -- Process is the scope, this is also the process for which drivers can -- be created. -- Note: FIRST_STMT is the first statement, which can be get by: -- get_sequential_statement_chain (usual) -- get_associated_chain (for case statement). procedure Sem_Sequential_Statements_Internal (First_Stmt : Iir); -- Access to the current subprogram or process. Current_Subprogram: Iir := Null_Iir; function Get_Current_Subprogram return Iir is begin return Current_Subprogram; end Get_Current_Subprogram; -- Access to the current concurrent statement. -- Null_iir if no one. Current_Concurrent_Statement : Iir := Null_Iir; function Get_Current_Concurrent_Statement return Iir is begin return Current_Concurrent_Statement; end Get_Current_Concurrent_Statement; Current_Declarative_Region_With_Signals : Implicit_Signal_Declaration_Type := (Null_Iir, Null_Iir); procedure Push_Signals_Declarative_Part (Cell: out Implicit_Signal_Declaration_Type; Decls_Parent : Iir) is begin Cell := Current_Declarative_Region_With_Signals; Current_Declarative_Region_With_Signals := (Decls_Parent, Null_Iir); end Push_Signals_Declarative_Part; procedure Pop_Signals_Declarative_Part (Cell: in Implicit_Signal_Declaration_Type) is begin Current_Declarative_Region_With_Signals := Cell; end Pop_Signals_Declarative_Part; procedure Add_Declaration_For_Implicit_Signal (Sig : Iir) is Last : Iir renames Current_Declarative_Region_With_Signals.Last_Decl; begin if Current_Declarative_Region_With_Signals.Decls_Parent = Null_Iir then raise Internal_Error; end if; if Last = Null_Iir then Last := Get_Declaration_Chain (Current_Declarative_Region_With_Signals.Decls_Parent); end if; if Last = Null_Iir then Set_Declaration_Chain (Current_Declarative_Region_With_Signals.Decls_Parent, Sig); else while Get_Chain (Last) /= Null_Iir loop Last := Get_Chain (Last); end loop; Set_Chain (Last, Sig); end if; Last := Sig; end Add_Declaration_For_Implicit_Signal; -- LRM 8 Sequential statements. -- All statements may be labeled. -- Such labels are implicitly declared at the beginning of the declarative -- part of the innermost enclosing process statement of subprogram body. procedure Sem_Sequential_Labels (First_Stmt : Iir) is Stmt: Iir; Label: Name_Id; begin Stmt := First_Stmt; while Stmt /= Null_Iir loop Label := Get_Label (Stmt); if Label /= Null_Identifier then Sem_Scopes.Add_Name (Stmt); Name_Visible (Stmt); Xref_Decl (Stmt); end if; -- Some statements have sub-lists of statements. case Get_Kind (Stmt) is when Iir_Kind_For_Loop_Statement | Iir_Kind_While_Loop_Statement => Sem_Sequential_Labels (Get_Sequential_Statement_Chain (Stmt)); when Iir_Kind_If_Statement => declare Clause : Iir; begin Clause := Stmt; while Clause /= Null_Iir loop Sem_Sequential_Labels (Get_Sequential_Statement_Chain (Clause)); Clause := Get_Else_Clause (Clause); end loop; end; when Iir_Kind_Case_Statement => declare El : Iir; begin El := Get_Case_Statement_Alternative_Chain (Stmt); while El /= Null_Iir loop Sem_Sequential_Labels (Get_Associated_Chain (El)); El := Get_Chain (El); end loop; end; when others => null; end case; Stmt := Get_Chain (Stmt); end loop; end Sem_Sequential_Labels; procedure Fill_Array_From_Aggregate_Associated (Chain : Iir; Nbr : in out Natural; Arr : Iir_Array_Acc) is El : Iir; Ass : Iir; begin El := Chain; while El /= Null_Iir loop Ass := Get_Associated_Expr (El); if Get_Kind (Ass) = Iir_Kind_Aggregate then Fill_Array_From_Aggregate_Associated (Get_Association_Choices_Chain (Ass), Nbr, Arr); else if Arr /= null then Arr (Nbr) := Ass; end if; Nbr := Nbr + 1; end if; El := Get_Chain (El); end loop; end Fill_Array_From_Aggregate_Associated; -- Return TRUE iff there is no common elements designed by N1 and N2. -- N1 and N2 are static names. -- FIXME: The current implementation is completly wrong; should check from -- prefix to suffix. function Is_Disjoint (N1, N2: Iir) return Boolean is List1, List2 : Iir_List; El1, El2 : Iir; begin if N1 = N2 then return False; end if; if Get_Kind (N1) = Iir_Kind_Indexed_Name and then Get_Kind (N2) = Iir_Kind_Indexed_Name then if Is_Disjoint (Get_Prefix (N1), Get_Prefix (N2)) then return True; end if; -- Check indexes. List1 := Get_Index_List (N1); List2 := Get_Index_List (N2); for I in Natural loop El1 := Get_Nth_Element (List1, I); El2 := Get_Nth_Element (List2, I); exit when El1 = Null_Iir; El1 := Eval_Expr (El1); Replace_Nth_Element (List1, I, El1); El2 := Eval_Expr (El2); Replace_Nth_Element (List2, I, El2); -- EL are of discrete type. if Get_Value (El1) /= Get_Value (El2) then return True; end if; end loop; return False; elsif Get_Kind (N1) in Iir_Kinds_Denoting_Name and then Get_Kind (N2) in Iir_Kinds_Denoting_Name then return Get_Named_Entity (N1) /= Get_Named_Entity (N2); else return True; end if; end Is_Disjoint; procedure Check_Uniq_Aggregate_Associated (Aggr : Iir_Aggregate; Nbr : Natural) is Index : Natural; Arr : Iir_Array_Acc; Chain : Iir; V_I, V_J : Iir; begin Chain := Get_Association_Choices_Chain (Aggr); -- Count number of associated values, and create the array. -- Already done: use nbr. -- Fill_Array_From_Aggregate_Associated (List, Nbr, null); Arr := new Iir_Array (0 .. Nbr - 1); -- Fill the array. Index := 0; Fill_Array_From_Aggregate_Associated (Chain, Index, Arr); if Index /= Nbr then -- Should be the same. raise Internal_Error; end if; -- Check each element is uniq. for I in Arr.all'Range loop V_I := Name_To_Object (Arr (I)); if Get_Name_Staticness (V_I) = Locally then for J in 0 .. I - 1 loop V_J := Name_To_Object (Arr (J)); if Get_Name_Staticness (V_J) = Locally and then not Is_Disjoint (V_I, V_J) then Error_Msg_Sem ("target is assigned more than once", Arr (I)); Error_Msg_Sem (" (previous assignment is here)", Arr (J)); Free (Arr); return; end if; end loop; end if; end loop; Free (Arr); return; end Check_Uniq_Aggregate_Associated; -- Do checks for the target of an assignment. procedure Check_Simple_Signal_Target (Stmt : Iir; Target : Iir; Staticness : Iir_Staticness); -- STMT is used to localize the error (if any). procedure Check_Simple_Variable_Target (Stmt : Iir; Target : Iir; Staticness : Iir_Staticness); -- Semantic associed with signal mode. -- See §4.3.3 type Boolean_Array_Of_Iir_Mode is array (Iir_Mode) of Boolean; Iir_Mode_Readable : constant Boolean_Array_Of_Iir_Mode := (Iir_Unknown_Mode => False, Iir_In_Mode => True, Iir_Out_Mode => False, Iir_Inout_Mode => True, Iir_Buffer_Mode => True, Iir_Linkage_Mode => False); Iir_Mode_Writable : constant Boolean_Array_Of_Iir_Mode := (Iir_Unknown_Mode => False, Iir_In_Mode => False, Iir_Out_Mode => True, Iir_Inout_Mode => True, Iir_Buffer_Mode => True, Iir_Linkage_Mode => False); procedure Check_Aggregate_Target (Stmt : Iir; Target : Iir; Nbr : in out Natural) is Choice : Iir; Ass : Iir; begin Choice := Get_Association_Choices_Chain (Target); while Choice /= Null_Iir loop case Get_Kind (Choice) is when Iir_Kind_Choice_By_Range => -- LRM93 8.4 -- It is an error if an element association in such an -- aggregate contains an OTHERS choice or a choice that is -- a discrete range. Error_Msg_Sem ("discrete range choice not allowed for target", Choice); when Iir_Kind_Choice_By_Others => -- LRM93 8.4 -- It is an error if an element association in such an -- aggregate contains an OTHERS choice or a choice that is -- a discrete range. Error_Msg_Sem ("others choice not allowed for target", Choice); when Iir_Kind_Choice_By_Expression | Iir_Kind_Choice_By_Name | Iir_Kind_Choice_By_None => -- LRM93 9.4 -- Such a target may not only contain locally static signal -- names [...] Ass := Get_Associated_Expr (Choice); if Get_Kind (Ass) = Iir_Kind_Aggregate then Check_Aggregate_Target (Stmt, Ass, Nbr); else if Get_Kind (Stmt) = Iir_Kind_Variable_Assignment_Statement then Check_Simple_Variable_Target (Stmt, Ass, Locally); else Check_Simple_Signal_Target (Stmt, Ass, Locally); end if; Nbr := Nbr + 1; end if; when others => Error_Kind ("check_aggregate_target", Choice); end case; Choice := Get_Chain (Choice); end loop; end Check_Aggregate_Target; procedure Check_Simple_Signal_Target (Stmt : Iir; Target : Iir; Staticness : Iir_Staticness) is Target_Object : Iir; Target_Prefix : Iir; Guarded_Target : Tri_State_Type; Targ_Obj_Kind : Iir_Kind; begin Target_Object := Name_To_Object (Target); if Target_Object = Null_Iir then Error_Msg_Sem ("target is not a signal name", Target); return; end if; Target_Prefix := Get_Object_Prefix (Target_Object); Targ_Obj_Kind := Get_Kind (Target_Prefix); case Targ_Obj_Kind is when Iir_Kind_Interface_Signal_Declaration => if not Iir_Mode_Writable (Get_Mode (Target_Prefix)) then Error_Msg_Sem (Disp_Node (Target_Prefix) & " can't be assigned", Target); else Sem_Add_Driver (Target_Object, Stmt); end if; when Iir_Kind_Signal_Declaration => Sem_Add_Driver (Target_Object, Stmt); when Iir_Kind_Guard_Signal_Declaration => Error_Msg_Sem ("implicit GUARD signal cannot be assigned", Stmt); return; when others => Error_Msg_Sem ("target (" & Disp_Node (Get_Base_Name (Target)) & ") is not a signal", Stmt); return; end case; if Get_Name_Staticness (Target_Object) < Staticness then Error_Msg_Sem ("signal name must be static", Stmt); end if; -- LRM93 2.1.1.2 -- A formal signal parameter is a guarded signal if and only if -- it is associated with an actual signal that is a guarded -- signal. -- GHDL: a formal signal interface of a subprogram has no static -- kind. This is determined at run-time, according to the actual -- associated with the formal. -- GHDL: parent of target cannot be a function. if Targ_Obj_Kind = Iir_Kind_Interface_Signal_Declaration and then Get_Kind (Get_Parent (Target_Prefix)) = Iir_Kind_Procedure_Declaration then Guarded_Target := Unknown; else if Get_Signal_Kind (Target_Prefix) /= Iir_No_Signal_Kind then Guarded_Target := True; else Guarded_Target := False; end if; end if; case Get_Guarded_Target_State (Stmt) is when Unknown => Set_Guarded_Target_State (Stmt, Guarded_Target); when True | False => if Get_Guarded_Target_State (Stmt) /= Guarded_Target then -- LRM93 9.5 -- It is an error if the target of a concurrent signal -- assignment is neither a guarded target nor an -- unguarded target. Error_Msg_Sem ("guarded and unguarded target", Target); end if; end case; end Check_Simple_Signal_Target; procedure Check_Simple_Variable_Target (Stmt : Iir; Target : Iir; Staticness : Iir_Staticness) is Target_Object : Iir; Target_Prefix : Iir; begin Target_Object := Name_To_Object (Target); if Target_Object = Null_Iir then Error_Msg_Sem ("target is not a variable name", Stmt); return; end if; Target_Prefix := Get_Object_Prefix (Target_Object); case Get_Kind (Target_Prefix) is when Iir_Kind_Interface_Variable_Declaration => if not Iir_Mode_Writable (Get_Mode (Target_Prefix)) then Error_Msg_Sem (Disp_Node (Target_Prefix) & " cannot be written (bad mode)", Target); return; end if; when Iir_Kind_Variable_Declaration => null; when Iir_Kind_Implicit_Dereference | Iir_Kind_Dereference => -- LRM 3.3 -- An object designated by an access type is always an object of -- class variable. null; when others => Error_Msg_Sem (Disp_Node (Target_Prefix) & " is not a variable to be assigned", Stmt); return; end case; if Get_Name_Staticness (Target_Object) < Staticness then Error_Msg_Sem ("element of aggregate of variables must be a static name", Target); end if; end Check_Simple_Variable_Target; procedure Check_Target (Stmt : Iir; Target : Iir) is Nbr : Natural; begin if Get_Kind (Target) = Iir_Kind_Aggregate then Nbr := 0; Check_Aggregate_Target (Stmt, Target, Nbr); Check_Uniq_Aggregate_Associated (Target, Nbr); else if Get_Kind (Stmt) = Iir_Kind_Variable_Assignment_Statement then Check_Simple_Variable_Target (Stmt, Target, None); else Check_Simple_Signal_Target (Stmt, Target, None); end if; end if; end Check_Target; -- Return FALSE in case of error. function Sem_Signal_Assignment_Target_And_Option (Stmt: Iir; Sig_Type : Iir) return Boolean is -- The target of the assignment. Target: Iir; -- The value that will be assigned. Expr: Iir; Ok : Boolean; begin Ok := True; -- Find the signal. Target := Get_Target (Stmt); if Sig_Type = Null_Iir and then Get_Kind (Target) = Iir_Kind_Aggregate then -- Do not try to analyze an aggregate if its type is unknown. -- A target cannot be a qualified type and its type should be -- determine by the context (LRM93 7.3.2 Aggregates). Ok := False; else -- Analyze the target Target := Sem_Expression (Target, Sig_Type); if Target /= Null_Iir then Set_Target (Stmt, Target); Check_Target (Stmt, Target); Sem_Types.Set_Type_Has_Signal (Get_Type (Target)); else Ok := False; end if; end if; Expr := Get_Reject_Time_Expression (Stmt); if Expr /= Null_Iir then Expr := Sem_Expression (Expr, Time_Type_Definition); if Expr /= Null_Iir then Check_Read (Expr); Set_Reject_Time_Expression (Stmt, Expr); else Ok := False; end if; end if; return Ok; end Sem_Signal_Assignment_Target_And_Option; -- Semantize a waveform_list WAVEFORM_LIST that is assigned via statement -- ASSIGN_STMT to a subelement or a slice of a signal SIGNAL_DECL. procedure Sem_Waveform_Chain (Assign_Stmt: Iir; Waveform_Chain : Iir_Waveform_Element; Waveform_Type : in out Iir) is pragma Unreferenced (Assign_Stmt); Expr: Iir; We: Iir_Waveform_Element; Time, Last_Time : Iir_Int64; begin if Waveform_Chain = Null_Iir then -- Unaffected. return; end if; -- Start with -1 to allow after 0 ns. Last_Time := -1; We := Waveform_Chain; while We /= Null_Iir loop Expr := Get_We_Value (We); if Get_Kind (Expr) = Iir_Kind_Null_Literal then -- GHDL: allowed only if target is guarded; this is checked by -- sem_check_waveform_list. null; else if Get_Kind (Expr) = Iir_Kind_Aggregate and then Waveform_Type = Null_Iir then Error_Msg_Sem ("type of waveform is unknown, use qualified type", Expr); else Expr := Sem_Expression (Expr, Waveform_Type); if Expr /= Null_Iir then Check_Read (Expr); Set_We_Value (We, Eval_Expr_If_Static (Expr)); if Waveform_Type = Null_Iir then Waveform_Type := Get_Type (Expr); end if; end if; end if; end if; if Get_Time (We) /= Null_Iir then Expr := Sem_Expression (Get_Time (We), Time_Type_Definition); if Expr /= Null_Iir then Set_Time (We, Expr); Check_Read (Expr); if Get_Expr_Staticness (Expr) = Locally or else (Get_Kind (Expr) = Iir_Kind_Physical_Int_Literal and then Flags.Flag_Time_64) then -- LRM 8.4 -- It is an error if the time expression in a waveform -- element evaluates to a negative value. -- -- LRM 8.4.1 -- It is an error if the sequence of new transactions is not -- in ascending order with repect to time. -- GHDL: this must be checked at run-time, but this is also -- checked now for static expressions. if Get_Expr_Staticness (Expr) = Locally then -- The expression is static, and therefore may be -- evaluated. Expr := Eval_Expr (Expr); Set_Time (We, Expr); Time := Get_Value (Expr); else -- The expression is a physical literal (common case). -- Extract its value. Time := Get_Physical_Value (Expr); end if; if Time < 0 then Error_Msg_Sem ("waveform time expression must be >= 0", Expr); elsif Time <= Last_Time then Error_Msg_Sem ("time must be greather than previous transaction", Expr); else Last_Time := Time; end if; end if; end if; else if We /= Waveform_Chain then -- Time expression must be in ascending order. Error_Msg_Sem ("time expression required here", We); end if; -- LRM93 12.6.4 -- It is an error if the execution of any postponed process causes -- a delta cycle to occur immediatly after the current simulation -- cycle. -- GHDL: try to warn for such an error; note the context may be -- a procedure body. if Current_Concurrent_Statement /= Null_Iir then case Get_Kind (Current_Concurrent_Statement) is when Iir_Kind_Sensitized_Process_Statement | Iir_Kind_Process_Statement | Iir_Kind_Concurrent_Conditional_Signal_Assignment | Iir_Kind_Concurrent_Selected_Signal_Assignment => if Get_Postponed_Flag (Current_Concurrent_Statement) then Warning_Msg_Sem ("waveform may cause a delta cycle in a " & "postponed process", We); end if; when others => -- Context is a subprogram. null; end case; end if; Last_Time := 0; end if; We := Get_Chain (We); end loop; return; end Sem_Waveform_Chain; -- Semantize a waveform chain WAVEFORM_CHAIN that is assigned via statement -- ASSIGN_STMT to a subelement or a slice of a signal SIGNAL_DECL. procedure Sem_Check_Waveform_Chain (Assign_Stmt: Iir; Waveform_Chain: Iir_Waveform_Element) is We: Iir_Waveform_Element; Expr : Iir; Targ_Type : Iir; begin if Waveform_Chain = Null_Iir then return; end if; Targ_Type := Get_Type (Get_Target (Assign_Stmt)); We := Waveform_Chain; while We /= Null_Iir loop Expr := Get_We_Value (We); if Get_Kind (Expr) = Iir_Kind_Null_Literal then -- This is a null waveform element. -- LRM93 8.4.1 -- It is an error if the target of a signal assignment statement -- containing a null waveform is not a guarded signal or an -- aggregate of guarded signals. if Get_Guarded_Target_State (Assign_Stmt) = False then Error_Msg_Sem ("null transactions can be assigned only to guarded signals", Assign_Stmt); end if; else if not Check_Implicit_Conversion (Targ_Type, Expr) then Error_Msg_Sem ("length of value does not match length of target", We); end if; end if; We := Get_Chain (We); end loop; end Sem_Check_Waveform_Chain; procedure Sem_Signal_Assignment (Stmt: Iir) is Target : Iir; Waveform_Type : Iir; begin Target := Get_Target (Stmt); if Get_Kind (Target) /= Iir_Kind_Aggregate then if not Sem_Signal_Assignment_Target_And_Option (Stmt, Null_Iir) then return; end if; -- check the expression. Waveform_Type := Get_Type (Get_Target (Stmt)); if Waveform_Type /= Null_Iir then Sem_Waveform_Chain (Stmt, Get_Waveform_Chain (Stmt), Waveform_Type); Sem_Check_Waveform_Chain (Stmt, Get_Waveform_Chain (Stmt)); end if; else Waveform_Type := Null_Iir; Sem_Waveform_Chain (Stmt, Get_Waveform_Chain (Stmt), Waveform_Type); if Waveform_Type = Null_Iir or else not Sem_Signal_Assignment_Target_And_Option (Stmt, Waveform_Type) then return; end if; Sem_Check_Waveform_Chain (Stmt, Get_Waveform_Chain (Stmt)); end if; end Sem_Signal_Assignment; procedure Sem_Variable_Assignment (Stmt: Iir) is Target: Iir; Expr: Iir; Target_Type : Iir; begin -- Find the variable. Target := Get_Target (Stmt); Expr := Get_Expression (Stmt); -- LRM93 8.5 Variable assignment statement -- If the target of the variable assignment statement is in the form of -- an aggregate, then the type of the aggregate must be determinable -- from the context, excluding the aggregate itself but including the -- fact that the type of the aggregate must be a composite type. The -- base type of the expression on the right-hand side must be the -- same as the base type of the aggregate. -- -- GHDL: this means that the type can only be deduced from the -- expression (and not from the target). if Get_Kind (Target) = Iir_Kind_Aggregate then if Get_Kind (Expr) = Iir_Kind_Aggregate then Error_Msg_Sem ("can't determine type, use type qualifier", Expr); return; end if; Expr := Sem_Composite_Expression (Get_Expression (Stmt)); if Expr = Null_Iir then return; end if; Check_Read (Expr); Set_Expression (Stmt, Expr); Target_Type := Get_Type (Expr); -- An aggregate cannot be analyzed without a type. -- FIXME: partially analyze the aggregate ? if Target_Type = Null_Iir then return; end if; -- FIXME: check elements are identified at most once. else Target_Type := Null_Iir; end if; Target := Sem_Expression (Target, Target_Type); if Target = Null_Iir then return; end if; Set_Target (Stmt, Target); Check_Target (Stmt, Target); if Get_Kind (Target) /= Iir_Kind_Aggregate then Expr := Sem_Expression (Expr, Get_Type (Target)); if Expr /= Null_Iir then Check_Read (Expr); Expr := Eval_Expr_If_Static (Expr); Set_Expression (Stmt, Expr); end if; end if; if not Check_Implicit_Conversion (Get_Type (Target), Expr) then Warning_Msg_Sem ("expression length does not match target length", Stmt); end if; end Sem_Variable_Assignment; procedure Sem_Return_Statement (Stmt: Iir_Return_Statement) is Expr: Iir; begin if Current_Subprogram = Null_Iir then Error_Msg_Sem ("return statement not in a subprogram body", Stmt); return; end if; Expr := Get_Expression (Stmt); case Get_Kind (Current_Subprogram) is when Iir_Kind_Procedure_Declaration => if Expr /= Null_Iir then Error_Msg_Sem ("return in a procedure can't have an expression", Stmt); end if; return; when Iir_Kind_Function_Declaration => if Expr = Null_Iir then Error_Msg_Sem ("return in a function must have an expression", Stmt); return; end if; when Iir_Kinds_Process_Statement => Error_Msg_Sem ("return statement not allowed in a process", Stmt); return; when others => Error_Kind ("sem_return_statement", Stmt); end case; Set_Type (Stmt, Get_Return_Type (Current_Subprogram)); Expr := Sem_Expression (Expr, Get_Return_Type (Current_Subprogram)); if Expr /= Null_Iir then Check_Read (Expr); Set_Expression (Stmt, Eval_Expr_If_Static (Expr)); end if; end Sem_Return_Statement; -- Sem for concurrent and sequential assertion statements. procedure Sem_Report_Statement (Stmt : Iir) is Expr : Iir; begin Expr := Get_Report_Expression (Stmt); if Expr /= Null_Iir then Expr := Sem_Expression (Expr, String_Type_Definition); Check_Read (Expr); Expr := Eval_Expr_If_Static (Expr); Set_Report_Expression (Stmt, Expr); end if; Expr := Get_Severity_Expression (Stmt); if Expr /= Null_Iir then Expr := Sem_Expression (Expr, Severity_Level_Type_Definition); Check_Read (Expr); Set_Severity_Expression (Stmt, Expr); end if; end Sem_Report_Statement; procedure Sem_Assertion_Statement (Stmt: Iir) is Expr : Iir; begin Expr := Get_Assertion_Condition (Stmt); Expr := Sem_Condition (Expr); Expr := Eval_Expr_If_Static (Expr); Set_Assertion_Condition (Stmt, Expr); Sem_Report_Statement (Stmt); end Sem_Assertion_Statement; -- Semantize a list of case choice LIST, and check for correct CHOICE type. procedure Sem_Case_Choices (Choice : Iir; Chain : in out Iir; Loc : Location_Type) is -- Check restrictions on the expression of a One-Dimensional Character -- Array Type (ODCAT) given by LRM 8.8 -- Return FALSE in case of violation. function Check_Odcat_Expression (Expr : Iir) return Boolean is Expr_Type : constant Iir := Get_Type (Expr); begin -- LRM 8.8 Case Statement -- If the expression is of a one-dimensional character array type, -- then the expression must be one of the following: case Get_Kind (Expr) is when Iir_Kinds_Object_Declaration | Iir_Kind_Selected_Element => -- FIXME: complete the list. -- * the name of an object whose subtype is locally static. if Get_Type_Staticness (Expr_Type) /= Locally then Error_Msg_Sem ("object subtype is not locally static", Choice); return False; end if; when Iir_Kind_Indexed_Name => -- LRM93 -- * an indexed name whose prefix is one of the members of -- this list and whose indexing expressions are locally -- static expression. if Flags.Vhdl_Std = Vhdl_87 then Error_Msg_Sem ("indexed name not allowed here in vhdl87", Expr); return False; end if; if not Check_Odcat_Expression (Get_Prefix (Expr)) then return False; end if; -- GHDL: I don't understand why the indexing expressions -- must be locally static. So I don't check this in 93c. if Flags.Vhdl_Std /= Vhdl_93c and then Get_Expr_Staticness (Get_First_Element (Get_Index_List (Expr))) /= Locally then Error_Msg_Sem ("indexing expression must be locally static", Expr); return False; end if; when Iir_Kind_Slice_Name => -- LRM93 -- * a slice name whose prefix is one of the members of this -- list and whose discrete range is a locally static -- discrete range. -- LRM87/INT1991 IR96 -- then the expression must be either a slice name whose -- discrete range is locally static, or .. if False and Flags.Vhdl_Std = Vhdl_87 then Error_Msg_Sem ("slice not allowed as case expression in vhdl87", Expr); return False; end if; if not Check_Odcat_Expression (Get_Prefix (Expr)) then return False; end if; if Get_Type_Staticness (Expr_Type) /= Locally then Error_Msg_Sem ("slice discrete range must be locally static", Expr); return False; end if; when Iir_Kind_Function_Call => -- LRM93 -- * a function call whose return type mark denotes a -- locally static subtype. if Flags.Vhdl_Std = Vhdl_87 then Error_Msg_Sem ("function call not allowed here in vhdl87", Expr); return False; end if; if Get_Type_Staticness (Expr_Type) /= Locally then Error_Msg_Sem ("function call type is not locally static", Expr); end if; when Iir_Kind_Qualified_Expression | Iir_Kind_Type_Conversion => -- * a qualified expression or type conversion whose type mark -- denotes a locally static subtype. if Get_Type_Staticness (Expr_Type) /= Locally then Error_Msg_Sem ("type mark is not a locally static subtype", Expr); return False; end if; when Iir_Kind_Simple_Name | Iir_Kind_Selected_Name => return Check_Odcat_Expression (Get_Named_Entity (Expr)); when others => Error_Msg_Sem ("bad form of case expression (refer to LRM 8.8)", Choice); return False; end case; return True; end Check_Odcat_Expression; Choice_Type : Iir; Low, High : Iir; El_Type : Iir; begin -- LRM 8.8 Case Statement -- The expression must be of a discrete type, or of a one-dimensional -- array type whose element base type is a character type. Choice_Type := Get_Type (Choice); case Get_Kind (Choice_Type) is when Iir_Kinds_Discrete_Type_Definition => Sem_Choices_Range (Chain, Choice_Type, False, True, Loc, Low, High); when Iir_Kind_Array_Subtype_Definition | Iir_Kind_Array_Type_Definition => if not Is_One_Dimensional_Array_Type (Choice_Type) then Error_Msg_Sem ("expression must be of a one-dimensional array type", Choice); return; end if; El_Type := Get_Base_Type (Get_Element_Subtype (Choice_Type)); if Get_Kind (El_Type) /= Iir_Kind_Enumeration_Type_Definition then -- FIXME: check character. Error_Msg_Sem ("element type of the expression must be a character type", Choice); return; end if; if not Check_Odcat_Expression (Choice) then return; end if; Sem_String_Choices_Range (Chain, Choice); when others => Error_Msg_Sem ("type of expression must be discrete", Choice); end case; end Sem_Case_Choices; procedure Sem_Case_Statement (Stmt: Iir_Case_Statement) is Expr: Iir; Chain : Iir; El: Iir; begin Expr := Get_Expression (Stmt); -- FIXME: overload. Expr := Sem_Case_Expression (Expr); if Expr = Null_Iir then return; end if; Check_Read (Expr); Set_Expression (Stmt, Expr); Chain := Get_Case_Statement_Alternative_Chain (Stmt); Sem_Case_Choices (Expr, Chain, Get_Location (Stmt)); Set_Case_Statement_Alternative_Chain (Stmt, Chain); -- Sem on associated. El := Chain; while El /= Null_Iir loop Sem_Sequential_Statements_Internal (Get_Associated_Chain (El)); El := Get_Chain (El); end loop; end Sem_Case_Statement; -- Sem the sensitivity list LIST. procedure Sem_Sensitivity_List (List: Iir_Designator_List) is El: Iir; Res: Iir; Prefix : Iir; begin if List = Iir_List_All then return; end if; for I in Natural loop -- El is an iir_identifier. El := Get_Nth_Element (List, I); exit when El = Null_Iir; Sem_Name (El); Res := Get_Named_Entity (El); if Res = Error_Mark then null; elsif Is_Overload_List (Res) or else not Is_Object_Name (Res) then Error_Msg_Sem ("a sensitivity element must be a signal name", El); else Res := Finish_Sem_Name (El); Prefix := Get_Object_Prefix (Res); case Get_Kind (Prefix) is when Iir_Kind_Signal_Declaration | Iir_Kind_Guard_Signal_Declaration | Iir_Kinds_Signal_Attribute => null; when Iir_Kind_Interface_Signal_Declaration => if not Iir_Mode_Readable (Get_Mode (Prefix)) then Error_Msg_Sem (Disp_Node (Res) & " of mode out" & " can't be in a sensivity list", El); end if; when others => Error_Msg_Sem (Disp_Node (Res) & " is neither a signal nor a port", El); end case; -- LRM 9.2 -- Only static signal names (see section 6.1) for which reading -- is permitted may appear in the sensitivity list of a process -- statement. -- LRM 8.1 Wait statement -- Each signal name in the sensitivity list must be a static -- signal name, and each name must denote a signal for which -- reading is permitted. if Get_Name_Staticness (Res) < Globally then Error_Msg_Sem ("sensitivity element " & Disp_Node (Res) & " must be a static name", El); end if; Replace_Nth_Element (List, I, Res); end if; end loop; end Sem_Sensitivity_List; procedure Sem_Wait_Statement (Stmt: Iir_Wait_Statement) is Expr: Iir; Sensitivity_List : Iir_List; begin -- Check validity. case Get_Kind (Current_Subprogram) is when Iir_Kind_Process_Statement => null; when Iir_Kinds_Function_Declaration => -- LRM93 §8.2 -- It is an error if a wait statement appears in a function -- subprogram [...] Error_Msg_Sem ("wait statement not allowed in a function subprogram", Stmt); return; when Iir_Kinds_Procedure_Declaration => -- LRM93 §8.2 -- [It is an error ...] or in a procedure that has a parent that -- is a function subprogram. -- LRM93 §8.2 -- [...] or in a procedure that has a parent that is such a -- process statement. -- GHDL: this is checked at the end of analysis or during -- elaboration. Set_Wait_State (Current_Subprogram, True); when Iir_Kind_Sensitized_Process_Statement => -- LRM93 §8.2 -- Furthermore, it is an error if a wait statement appears in an -- explicit process statement that includes a sensitivity list, -- [...] Error_Msg_Sem ("wait statement not allowed in a sensitized process", Stmt); return; when others => raise Internal_Error; end case; Sensitivity_List := Get_Sensitivity_List (Stmt); if Sensitivity_List /= Null_Iir_List then Sem_Sensitivity_List (Sensitivity_List); end if; Expr := Get_Condition_Clause (Stmt); if Expr /= Null_Iir then Expr := Sem_Condition (Expr); Set_Condition_Clause (Stmt, Expr); end if; Expr := Get_Timeout_Clause (Stmt); if Expr /= Null_Iir then Expr := Sem_Expression (Expr, Time_Type_Definition); if Expr /= Null_Iir then Check_Read (Expr); Expr := Eval_Expr_If_Static (Expr); Set_Timeout_Clause (Stmt, Expr); if Get_Expr_Staticness (Expr) = Locally and then Get_Value (Expr) < 0 then Error_Msg_Sem ("timeout value must be positive", Stmt); end if; end if; end if; end Sem_Wait_Statement; procedure Sem_Exit_Next_Statement (Stmt : Iir) is Cond: Iir; Loop_Label : Iir; Loop_Stmt: Iir; P : Iir; begin Cond := Get_Condition (Stmt); if Cond /= Null_Iir then Cond := Sem_Condition (Cond); Set_Condition (Stmt, Cond); end if; Loop_Label := Get_Loop_Label (Stmt); if Loop_Label /= Null_Iir then Loop_Label := Sem_Denoting_Name (Loop_Label); Set_Loop_Label (Stmt, Loop_Label); Loop_Stmt := Get_Named_Entity (Loop_Label); case Get_Kind (Loop_Stmt) is when Iir_Kind_For_Loop_Statement | Iir_Kind_While_Loop_Statement => null; when others => Error_Class_Match (Loop_Label, "loop statement"); Loop_Stmt := Null_Iir; end case; else Loop_Stmt := Null_Iir; end if; -- Check the current statement is inside the labeled loop. P := Stmt; loop P := Get_Parent (P); case Get_Kind (P) is when Iir_Kind_While_Loop_Statement | Iir_Kind_For_Loop_Statement => if Loop_Stmt = Null_Iir or else P = Loop_Stmt then exit; end if; when Iir_Kind_If_Statement | Iir_Kind_Elsif | Iir_Kind_Case_Statement => null; when others => -- FIXME: should emit a message for label mismatch. Error_Msg_Sem ("exit/next must be inside a loop", Stmt); exit; end case; end loop; end Sem_Exit_Next_Statement; -- Process is the scope, this is also the process for which drivers can -- be created. procedure Sem_Sequential_Statements_Internal (First_Stmt : Iir) is Stmt: Iir; begin Stmt := First_Stmt; while Stmt /= Null_Iir loop case Get_Kind (Stmt) is when Iir_Kind_Null_Statement => null; when Iir_Kind_If_Statement => declare Clause: Iir := Stmt; Cond: Iir; begin while Clause /= Null_Iir loop Cond := Get_Condition (Clause); if Cond /= Null_Iir then Cond := Sem_Condition (Cond); Set_Condition (Clause, Cond); end if; Sem_Sequential_Statements_Internal (Get_Sequential_Statement_Chain (Clause)); Clause := Get_Else_Clause (Clause); end loop; end; when Iir_Kind_For_Loop_Statement => declare Iterator: Iir; begin -- LRM 10.1 Declarative region -- 9. A loop statement. Open_Declarative_Region; Set_Is_Within_Flag (Stmt, True); Iterator := Get_Parameter_Specification (Stmt); Sem_Scopes.Add_Name (Iterator); Sem_Iterator (Iterator, None); Set_Visible_Flag (Iterator, True); Sem_Sequential_Statements_Internal (Get_Sequential_Statement_Chain (Stmt)); Set_Is_Within_Flag (Stmt, False); Close_Declarative_Region; end; when Iir_Kind_While_Loop_Statement => declare Cond: Iir; begin Cond := Get_Condition (Stmt); if Cond /= Null_Iir then Cond := Sem_Condition (Cond); Set_Condition (Stmt, Cond); end if; Sem_Sequential_Statements_Internal (Get_Sequential_Statement_Chain (Stmt)); end; when Iir_Kind_Signal_Assignment_Statement => Sem_Signal_Assignment (Stmt); if Current_Concurrent_Statement /= Null_Iir and then Get_Kind (Current_Concurrent_Statement) in Iir_Kinds_Process_Statement and then Get_Passive_Flag (Current_Concurrent_Statement) then Error_Msg_Sem ("signal statement forbidden in passive process", Stmt); end if; when Iir_Kind_Variable_Assignment_Statement => Sem_Variable_Assignment (Stmt); when Iir_Kind_Return_Statement => Sem_Return_Statement (Stmt); when Iir_Kind_Assertion_Statement => Sem_Assertion_Statement (Stmt); when Iir_Kind_Report_Statement => Sem_Report_Statement (Stmt); when Iir_Kind_Case_Statement => Sem_Case_Statement (Stmt); when Iir_Kind_Wait_Statement => Sem_Wait_Statement (Stmt); when Iir_Kind_Procedure_Call_Statement => Sem_Procedure_Call (Get_Procedure_Call (Stmt), Stmt); when Iir_Kind_Next_Statement | Iir_Kind_Exit_Statement => Sem_Exit_Next_Statement (Stmt); when others => Error_Kind ("sem_sequential_statements_Internal", Stmt); end case; Stmt := Get_Chain (Stmt); end loop; end Sem_Sequential_Statements_Internal; procedure Sem_Sequential_Statements (Decl : Iir; Body_Parent : Iir) is Outer_Subprogram: Iir; begin Outer_Subprogram := Current_Subprogram; Current_Subprogram := Decl; -- Sem declarations Sem_Sequential_Labels (Get_Sequential_Statement_Chain (Body_Parent)); Sem_Declaration_Chain (Body_Parent); Sem_Specification_Chain (Body_Parent, Null_Iir); -- Sem statements. Sem_Sequential_Statements_Internal (Get_Sequential_Statement_Chain (Body_Parent)); Check_Full_Declaration (Body_Parent, Body_Parent); Current_Subprogram := Outer_Subprogram; end Sem_Sequential_Statements; -- Sem the instantiated unit of STMT and return the node constaining -- ports and generics (either a entity_declaration or a component -- declaration). function Sem_Instantiated_Unit (Stmt : Iir_Component_Instantiation_Statement) return Iir is Inst : Iir; Comp_Name : Iir; Comp : Iir; begin Inst := Get_Instantiated_Unit (Stmt); if Get_Kind (Inst) in Iir_Kinds_Denoting_Name then Comp := Get_Named_Entity (Inst); if Comp /= Null_Iir then -- Already semantized before, while trying to separate -- concurrent procedure calls from instantiation stmts. pragma Assert (Get_Kind (Comp) = Iir_Kind_Component_Declaration); return Comp; end if; -- The component may be an entity or a configuration. Comp_Name := Sem_Denoting_Name (Inst); Set_Instantiated_Unit (Stmt, Comp_Name); Comp := Get_Named_Entity (Comp_Name); if Get_Kind (Comp) /= Iir_Kind_Component_Declaration then Error_Class_Match (Comp_Name, "component"); return Null_Iir; end if; return Comp; else return Sem_Entity_Aspect (Inst); end if; end Sem_Instantiated_Unit; procedure Sem_Component_Instantiation_Statement (Stmt: Iir_Component_Instantiation_Statement; Is_Passive : Boolean) is Decl : Iir; Entity_Unit : Iir_Design_Unit; Bind : Iir_Binding_Indication; begin -- FIXME: move this check in parse ? if Is_Passive then Error_Msg_Sem ("component instantiation forbidden in entity", Stmt); end if; -- Check for label. -- This cannot be moved in parse since a procedure_call may be revert -- into a component instantiation. if Get_Label (Stmt) = Null_Identifier then Error_Msg_Sem ("component instantiation requires a label", Stmt); end if; -- Look for the component. Decl := Sem_Instantiated_Unit (Stmt); if Decl = Null_Iir then return; end if; -- The association Sem_Generic_Port_Association_Chain (Decl, Stmt); -- FIXME: add sources for signals, in order to detect multiple sources -- to unresolved signals. -- What happen if the component is not bound ? -- Create a default binding indication if necessary. if Get_Component_Configuration (Stmt) = Null_Iir and then Get_Kind (Decl) = Iir_Kind_Component_Declaration then Entity_Unit := Get_Visible_Entity_Declaration (Decl); if Entity_Unit = Null_Iir then if Flags.Warn_Default_Binding and then not Flags.Flag_Elaborate then Warning_Msg_Sem ("no default binding for instantiation of " & Disp_Node (Decl), Stmt); Explain_No_Visible_Entity (Decl); end if; elsif Flags.Flag_Elaborate and then (Flags.Flag_Elaborate_With_Outdated or else Get_Date (Entity_Unit) in Date_Valid) then Bind := Sem_Create_Default_Binding_Indication (Decl, Entity_Unit, Stmt, False); Set_Default_Binding_Indication (Stmt, Bind); end if; end if; end Sem_Component_Instantiation_Statement; -- Note: a statement such as -- label1: name; -- can be parsed as a procedure call statement or as a -- component instantiation statement. -- Check now and revert in case of error. function Sem_Concurrent_Procedure_Call_Statement (Stmt : Iir; Is_Passive : Boolean) return Iir is Call : Iir_Procedure_Call; Decl : Iir; Label : Name_Id; N_Stmt : Iir_Component_Instantiation_Statement; Imp : Iir; begin Call := Get_Procedure_Call (Stmt); if Get_Parameter_Association_Chain (Call) = Null_Iir then Imp := Get_Prefix (Call); Sem_Name (Imp); Set_Prefix (Call, Imp); Decl := Get_Named_Entity (Imp); if Get_Kind (Decl) = Iir_Kind_Component_Declaration then N_Stmt := Create_Iir (Iir_Kind_Component_Instantiation_Statement); Label := Get_Label (Stmt); Set_Label (N_Stmt, Label); Set_Parent (N_Stmt, Get_Parent (Stmt)); Set_Instantiated_Unit (N_Stmt, Finish_Sem_Name (Imp)); Location_Copy (N_Stmt, Stmt); if Label /= Null_Identifier then -- A component instantiation statement must have -- a label, this condition is checked during the -- sem of the statement. Sem_Scopes.Replace_Name (Label, Stmt, N_Stmt); end if; Free_Iir (Stmt); Free_Iir (Call); Sem_Component_Instantiation_Statement (N_Stmt, Is_Passive); return N_Stmt; end if; end if; Sem_Procedure_Call (Call, Stmt); if Is_Passive then Imp := Get_Implementation (Call); if Get_Kind (Imp) = Iir_Kind_Procedure_Declaration then Decl := Get_Interface_Declaration_Chain (Imp); while Decl /= Null_Iir loop if Get_Mode (Decl) in Iir_Out_Modes then Error_Msg_Sem (Disp_Node (Imp) & " is not passive", Stmt); exit; end if; Decl := Get_Chain (Decl); end loop; end if; end if; return Stmt; end Sem_Concurrent_Procedure_Call_Statement; procedure Sem_Block_Statement (Stmt: Iir_Block_Statement) is Expr: Iir; Guard : Iir_Guard_Signal_Declaration; Header : Iir_Block_Header; Generic_Chain : Iir; Port_Chain : Iir; begin -- LRM 10.1 Declarative region. -- 7. A block statement. Open_Declarative_Region; Set_Is_Within_Flag (Stmt, True); Header := Get_Block_Header (Stmt); if Header /= Null_Iir then Generic_Chain := Get_Generic_Chain (Header); Sem_Interface_Chain (Generic_Chain, Generic_Interface_List); Port_Chain := Get_Port_Chain (Header); Sem_Interface_Chain (Port_Chain, Port_Interface_List); -- LRM 9.1 -- Such actuals are evaluated in the context of the enclosing -- declarative region. -- GHDL: close the declarative region... Set_Is_Within_Flag (Stmt, False); Close_Declarative_Region; Sem_Generic_Port_Association_Chain (Header, Header); -- ... and reopen-it. Open_Declarative_Region; Set_Is_Within_Flag (Stmt, True); Add_Declarations_From_Interface_Chain (Generic_Chain); Add_Declarations_From_Interface_Chain (Port_Chain); end if; -- LRM93 9.1 -- If a guard expression appears after the reserved word BLOCK, then a -- signal with the simple name GUARD of predefined type BOOLEAN is -- implicitly declared at the beginning of the declarative part of the -- block, and the guard expression defined the value of that signal at -- any given time. Guard := Get_Guard_Decl (Stmt); if Guard /= Null_Iir then -- LRM93 9.1 -- The type of the guard expression must be type BOOLEAN. -- GHDL: guard expression must be semantized before creating the -- implicit GUARD signal, since the expression may reference GUARD. Set_Expr_Staticness (Guard, None); Set_Name_Staticness (Guard, Locally); Expr := Get_Guard_Expression (Guard); Expr := Sem_Condition (Expr); if Expr /= Null_Iir then Set_Guard_Expression (Guard, Expr); end if; -- FIXME: should extract sensivity now and set the has_active flag -- on signals, since the guard expression is evaluated when one of -- its signal is active. However, how can a bug be introduced by -- evaluating only when signals have events ? -- the guard expression is an implicit definition of a signal named -- GUARD. Create this definition. This is necessary for the type. Set_Identifier (Guard, Std_Names.Name_Guard); Set_Type (Guard, Boolean_Type_Definition); Set_Block_Statement (Guard, Stmt); Sem_Scopes.Add_Name (Guard); Set_Visible_Flag (Guard, True); end if; Sem_Block (Stmt, True); Set_Is_Within_Flag (Stmt, False); Close_Declarative_Region; end Sem_Block_Statement; procedure Sem_Generate_Statement (Stmt : Iir_Generate_Statement) is Scheme : Iir; begin -- LRM93 10.1 Declarative region. -- 12. A generate statement. Open_Declarative_Region; Scheme := Get_Generation_Scheme (Stmt); if Get_Kind (Scheme) = Iir_Kind_Iterator_Declaration then Sem_Scopes.Add_Name (Scheme); -- LRM93 §7.4.2 (Globally Static Primaries) -- 4. a generate parameter; Sem_Iterator (Scheme, Globally); Set_Visible_Flag (Scheme, True); -- LRM93 §9.7 -- The discrete range in a generation scheme of the first form must -- be a static discrete range; if Get_Type (Scheme) /= Null_Iir and then Get_Type_Staticness (Get_Type (Scheme)) < Globally then Error_Msg_Sem ("range must be a static discrete range", Stmt); end if; else Scheme := Sem_Condition (Scheme); -- LRM93 §9.7 -- the condition in a generation scheme of the second form must be -- a static expression. if Scheme /= Null_Iir and then Get_Expr_Staticness (Scheme) < Globally then Error_Msg_Sem ("condition must be a static expression", Stmt); else Set_Generation_Scheme (Stmt, Scheme); end if; end if; Sem_Block (Stmt, True); -- Flags.Vhdl_Std /= Vhdl_87); Close_Declarative_Region; end Sem_Generate_Statement; procedure Sem_Process_Statement (Proc: Iir) is begin Set_Is_Within_Flag (Proc, True); -- LRM 10.1 -- 8. A process statement Open_Declarative_Region; -- Sem declarations Sem_Sequential_Statements (Proc, Proc); Close_Declarative_Region; Set_Is_Within_Flag (Proc, False); if Get_Kind (Proc) = Iir_Kind_Sensitized_Process_Statement and then Get_Callees_List (Proc) /= Null_Iir_List then -- Check there is no wait statement in subprograms called. -- Also in the case of all-sensitized process, check that package -- subprograms don't read signals. Sem.Add_Analysis_Checks_List (Proc); end if; end Sem_Process_Statement; procedure Sem_Sensitized_Process_Statement (Proc: Iir_Sensitized_Process_Statement) is begin Sem_Sensitivity_List (Get_Sensitivity_List (Proc)); Sem_Process_Statement (Proc); end Sem_Sensitized_Process_Statement; procedure Sem_Guard (Stmt: Iir) is Guard: Iir; Guard_Interpretation : Name_Interpretation_Type; begin Guard := Get_Guard (Stmt); if Guard = Null_Iir then -- This assignment is not guarded. -- LRM93 9.5 -- It is an error if a concurrent signal assignment is not a guarded -- assignment, and the target of the concurrent signal assignment -- is a guarded target. if Get_Guarded_Target_State (Stmt) = True then Error_Msg_Sem ("not a guarded assignment for a guarded target", Stmt); end if; return; end if; if Guard /= Stmt then -- if set, guard must be equal to stmt here. raise Internal_Error; end if; Guard_Interpretation := Get_Interpretation (Std_Names.Name_Guard); if not Valid_Interpretation (Guard_Interpretation) then Error_Msg_Sem ("no guard signals for this guarded assignment", Stmt); return; end if; Guard := Get_Declaration (Guard_Interpretation); -- LRM93 9.5: -- The signal GUARD [...] an explicitly declared signal of type -- BOOLEAN that is visible at the point of the concurrent signal -- assignment statement -- FIXME. case Get_Kind (Guard) is when Iir_Kind_Signal_Declaration | Iir_Kind_Interface_Signal_Declaration | Iir_Kind_Guard_Signal_Declaration => null; when others => Error_Msg_Sem ("visible GUARD object is not a signal", Stmt); Error_Msg_Sem ("GUARD object is " & Disp_Node (Guard), Stmt); return; end case; if Get_Type (Guard) /= Boolean_Type_Definition then Error_Msg_Sem ("GUARD is not of boolean type", Guard); end if; Set_Guard (Stmt, Guard); end Sem_Guard; procedure Sem_Concurrent_Conditional_Signal_Assignment (Stmt: Iir_Concurrent_Conditional_Signal_Assignment) is Cond_Wf : Iir_Conditional_Waveform; Expr : Iir; Wf_Chain : Iir_Waveform_Element; Target_Type : Iir; Target : Iir; begin Target := Get_Target (Stmt); if Get_Kind (Target) /= Iir_Kind_Aggregate then if not Sem_Signal_Assignment_Target_And_Option (Stmt, Null_Iir) then return; end if; Target := Get_Target (Stmt); Target_Type := Get_Type (Target); else Target_Type := Null_Iir; end if; Cond_Wf := Get_Conditional_Waveform_Chain (Stmt); while Cond_Wf /= Null_Iir loop Wf_Chain := Get_Waveform_Chain (Cond_Wf); Sem_Waveform_Chain (Stmt, Wf_Chain, Target_Type); Sem_Check_Waveform_Chain (Stmt, Wf_Chain); Expr := Get_Condition (Cond_Wf); if Expr /= Null_Iir then Expr := Sem_Condition (Expr); if Expr /= Null_Iir then Set_Condition (Cond_Wf, Expr); end if; end if; Cond_Wf := Get_Chain (Cond_Wf); end loop; Sem_Guard (Stmt); if Get_Kind (Target) = Iir_Kind_Aggregate then if not Sem_Signal_Assignment_Target_And_Option (Stmt, Target_Type) then return; end if; end if; end Sem_Concurrent_Conditional_Signal_Assignment; procedure Sem_Concurrent_Selected_Signal_Assignment (Stmt: Iir) is Expr: Iir; Chain : Iir; El: Iir; Waveform_Type : Iir; Target : Iir; Assoc_El : Iir; begin Target := Get_Target (Stmt); Chain := Get_Selected_Waveform_Chain (Stmt); Waveform_Type := Null_Iir; if Get_Kind (Target) = Iir_Kind_Aggregate then -- LRM 9.5 Concurrent Signal Assgnment Statements. -- The process statement equivalent to a concurrent signal assignment -- statement [...] is constructed as follows: [...] -- -- LRM 9.5.2 Selected Signa Assignment -- The characteristics of the selected expression, the waveforms and -- the choices in the selected assignment statement must be such that -- the case statement in the equivalent statement is a legal -- statement -- Find the first waveform that will appear in the equivalent -- process statement, and extract type from it. Assoc_El := Null_Iir; El := Chain; while El /= Null_Iir loop Assoc_El := Get_Associated_Expr (El); exit when Assoc_El /= Null_Iir; El := Get_Chain (El); end loop; if Assoc_El = Null_Iir then Error_Msg_Sem ("cannot determine type of the aggregate target", Target); else Sem_Waveform_Chain (Stmt, Assoc_El, Waveform_Type); end if; if Waveform_Type = Null_Iir then -- Type of target still unknown. -- Since the target is an aggregate, we won't be able to -- semantize it. -- Avoid a crash. return; end if; end if; if not Sem_Signal_Assignment_Target_And_Option (Stmt, Waveform_Type) then return; end if; Waveform_Type := Get_Type (Get_Target (Stmt)); -- Sem on associated. if Waveform_Type /= Null_Iir then El := Chain; while El /= Null_Iir loop Sem_Waveform_Chain (Stmt, Get_Associated_Chain (El), Waveform_Type); Sem_Check_Waveform_Chain (Stmt, Get_Associated_Chain (El)); El := Get_Chain (El); end loop; end if; -- The choices. Expr := Sem_Case_Expression (Get_Expression (Stmt)); if Expr = Null_Iir then return; end if; Check_Read (Expr); Set_Expression (Stmt, Expr); Sem_Case_Choices (Expr, Chain, Get_Location (Stmt)); Set_Selected_Waveform_Chain (Stmt, Chain); Sem_Guard (Stmt); end Sem_Concurrent_Selected_Signal_Assignment; procedure Simple_Simultaneous_Statement (Stmt : Iir) is Left, Right : Iir; Res_Type : Iir; begin Left := Get_Simultaneous_Left (Stmt); Right := Get_Simultaneous_Right (Stmt); Left := Sem_Expression_Ov (Left, Null_Iir); Right := Sem_Expression_Ov (Right, Null_Iir); -- Give up in case of error if Left = Null_Iir or else Right = Null_Iir then return; end if; Res_Type := Search_Compatible_Type (Get_Type (Left), Get_Type (Right)); if Res_Type = Null_Iir then Error_Msg_Sem ("types of left and right expressions are incompatible", Stmt); return; end if; -- FIXME: check for nature type... end Simple_Simultaneous_Statement; procedure Sem_Concurrent_Statement_Chain (Parent : Iir) is Is_Passive : constant Boolean := Get_Kind (Parent) = Iir_Kind_Entity_Declaration; El: Iir; Prev_El : Iir; Prev_Concurrent_Statement : Iir; Prev_Psl_Default_Clock : Iir; begin Prev_Concurrent_Statement := Current_Concurrent_Statement; Prev_Psl_Default_Clock := Current_Psl_Default_Clock; El := Get_Concurrent_Statement_Chain (Parent); Prev_El := Null_Iir; while El /= Null_Iir loop Current_Concurrent_Statement := El; case Get_Kind (El) is when Iir_Kind_Concurrent_Conditional_Signal_Assignment => if Is_Passive then Error_Msg_Sem ("signal assignment forbidden in entity", El); end if; Sem_Concurrent_Conditional_Signal_Assignment (El); when Iir_Kind_Concurrent_Selected_Signal_Assignment => if Is_Passive then Error_Msg_Sem ("signal assignment forbidden in entity", El); end if; Sem_Concurrent_Selected_Signal_Assignment (El); when Iir_Kind_Sensitized_Process_Statement => Set_Passive_Flag (El, Is_Passive); Sem_Sensitized_Process_Statement (El); when Iir_Kind_Process_Statement => Set_Passive_Flag (El, Is_Passive); Sem_Process_Statement (El); when Iir_Kind_Component_Instantiation_Statement => Sem_Component_Instantiation_Statement (El, Is_Passive); when Iir_Kind_Concurrent_Assertion_Statement => -- FIXME: must check assertion expressions does not contain -- non-passive subprograms ?? Sem_Assertion_Statement (El); when Iir_Kind_Block_Statement => if Is_Passive then Error_Msg_Sem ("block forbidden in entity", El); end if; Sem_Block_Statement (El); when Iir_Kind_Generate_Statement => if Is_Passive then Error_Msg_Sem ("generate statement forbidden in entity", El); end if; Sem_Generate_Statement (El); when Iir_Kind_Concurrent_Procedure_Call_Statement => declare Next_El : Iir; N_Stmt : Iir; begin Next_El := Get_Chain (El); N_Stmt := Sem_Concurrent_Procedure_Call_Statement (El, Is_Passive); if N_Stmt /= El then -- Replace this node. El := N_Stmt; if Prev_El = Null_Iir then Set_Concurrent_Statement_Chain (Parent, El); else Set_Chain (Prev_El, El); end if; Set_Chain (El, Next_El); end if; end; when Iir_Kind_Psl_Declaration => Sem_Psl.Sem_Psl_Declaration (El); when Iir_Kind_Psl_Assert_Statement | Iir_Kind_Psl_Cover_Statement => Sem_Psl.Sem_Psl_Assert_Statement (El); when Iir_Kind_Psl_Default_Clock => Sem_Psl.Sem_Psl_Default_Clock (El); when Iir_Kind_Simple_Simultaneous_Statement => Simple_Simultaneous_Statement (El); when others => Error_Kind ("sem_concurrent_statement_chain", El); end case; Prev_El := El; El := Get_Chain (El); end loop; Current_Concurrent_Statement := Prev_Concurrent_Statement; Current_Psl_Default_Clock := Prev_Psl_Default_Clock; end Sem_Concurrent_Statement_Chain; -- Put labels in declarative region. procedure Sem_Labels_Chain (Parent : Iir) is Stmt: Iir; Label: Name_Id; begin Stmt := Get_Concurrent_Statement_Chain (Parent); while Stmt /= Null_Iir loop case Get_Kind (Stmt) is when Iir_Kind_Psl_Declaration => -- Special case for in-lined PSL declarations. null; when others => Label := Get_Label (Stmt); if Label /= Null_Identifier then Sem_Scopes.Add_Name (Stmt); Name_Visible (Stmt); Xref_Decl (Stmt); end if; end case; -- INT-1991/issue report 27 -- Generate statements represent declarative region and have -- implicit declarative part. if False and then Flags.Vhdl_Std = Vhdl_87 and then Get_Kind (Stmt) = Iir_Kind_Generate_Statement then Sem_Labels_Chain (Stmt); end if; Stmt := Get_Chain (Stmt); end loop; end Sem_Labels_Chain; procedure Sem_Block (Blk: Iir; Sem_Decls : Boolean) is Implicit : Implicit_Signal_Declaration_Type; begin Push_Signals_Declarative_Part (Implicit, Blk); if Sem_Decls then Sem_Labels_Chain (Blk); Sem_Declaration_Chain (Blk); end if; Sem_Concurrent_Statement_Chain (Blk); if Sem_Decls then -- FIXME: do it only if there is conf. spec. in the declarative -- part. Sem_Specification_Chain (Blk, Blk); Check_Full_Declaration (Blk, Blk); end if; Pop_Signals_Declarative_Part (Implicit); end Sem_Block; -- Add a driver for SIG. -- STMT is used in case of error (it is the statement that creates the -- driver). -- Do nothing if: -- The current statement list does not belong to a process, -- SIG is a formal signal interface. procedure Sem_Add_Driver (Sig : Iir; Stmt : Iir) is Sig_Object : Iir; Sig_Object_Type : Iir; begin if Sig = Null_Iir then return; end if; Sig_Object := Get_Object_Prefix (Sig); Sig_Object_Type := Get_Type (Sig_Object); -- LRM 4.3.1.2 Signal Declaration -- It is an error if, after the elaboration of a description, a -- signal has multiple sources and it is not a resolved signal. -- Check for multiple driver for a unresolved signal declaration. -- Do this only if the object is a non-composite signal declaration. -- NOTE: THIS IS DISABLED, since the assignment may be within a -- generate statement. if False and then Get_Kind (Sig_Object) = Iir_Kind_Signal_Declaration and then Get_Kind (Sig_Object_Type) not in Iir_Kinds_Composite_Type_Definition and then not Get_Resolved_Flag (Sig_Object_Type) then if Get_Signal_Driver (Sig_Object) /= Null_Iir and then Get_Signal_Driver (Sig_Object) /= Current_Concurrent_Statement then Error_Msg_Sem ("unresolved " & Disp_Node (Sig_Object) & " has already a driver at " & Disp_Location (Get_Signal_Driver (Sig_Object)), Stmt); else Set_Signal_Driver (Sig_Object, Current_Concurrent_Statement); end if; end if; -- LRM 8.4.1 -- If a given procedure is declared by a declarative item that is not -- contained within a process statement, and if a signal assignment -- statement appears in that procedure, then the target of the -- assignment statement must be a formal parameter of the given -- procedure or of a parent of that procedure, or an aggregate of such -- formal parameters. -- Similarly, if a given procedure is declared by a declarative item -- that is not contained within a process statement and if a signal is -- associated with an INOUT or OUT mode signal parameter in a -- subprogram call within that procedure, then the signal so associated -- must be a formal parameter of the given procedure or of a parent of -- that procedure. if Current_Concurrent_Statement = Null_Iir or else (Get_Kind (Current_Concurrent_Statement) not in Iir_Kinds_Process_Statement) then -- Not within a process statement. if Current_Subprogram = Null_Iir then -- not within a subprogram: concurrent statement. return; end if; -- Within a subprogram. if Get_Kind (Sig_Object) = Iir_Kind_Signal_Declaration or else (Get_Kind (Get_Parent (Sig_Object)) /= Iir_Kind_Procedure_Declaration) then Error_Msg_Sem (Disp_Node (Sig_Object) & " is not a formal parameter", Stmt); end if; end if; end Sem_Add_Driver; end Sem_Stmts;