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Diffstat (limited to 'src/vhdl/iir_chains.ads')
| -rw-r--r-- | src/vhdl/iir_chains.ads | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/vhdl/iir_chains.ads b/src/vhdl/iir_chains.ads new file mode 100644 index 0000000..dc2f389 --- /dev/null +++ b/src/vhdl/iir_chains.ads @@ -0,0 +1,113 @@ +-- Chain handling. +-- 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 Iirs; use Iirs; +with Iir_Chain_Handling; +pragma Elaborate_All (Iir_Chain_Handling); + +package Iir_Chains is + -- Chains are simply linked list of iirs. + -- Elements of the chain are ordered. + -- Each element of a chain have a Chain field, which points to the next + -- element. + -- All elements of a chain have the same parent. This parent contains + -- a field which points to the first element of the chain. + -- Note: the parent is often the value of the Parent field, but sometimes + -- not. + + -- Chains can be covered very simply: + -- El : Iir; + -- begin + -- El := Get_xxx_Chain (Parent); + -- while El /= Null_Iir loop + -- * Handle element EL of the chain. + -- El := Get_Chain (El); + -- end loop; + + -- However, building a chain is a little bit more difficult if elements + -- have to be appended. Indeed, there is no direct access to the last + -- element of a chain. + -- An efficient way to build a chain is to keep the last element of it. + -- See Iir_Chain_Handling package. + + package Declaration_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Declaration_Chain, + Set_Chain_Start => Set_Declaration_Chain); + + package Interface_Declaration_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Interface_Declaration_Chain, + Set_Chain_Start => Set_Interface_Declaration_Chain); + + package Context_Items_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Context_Items, + Set_Chain_Start => Set_Context_Items); + + package Unit_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Unit_Chain, + Set_Chain_Start => Set_Unit_Chain); + + package Configuration_Item_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Configuration_Item_Chain, + Set_Chain_Start => Set_Configuration_Item_Chain); + + package Entity_Class_Entry_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Entity_Class_Entry_Chain, + Set_Chain_Start => Set_Entity_Class_Entry_Chain); + + package Conditional_Waveform_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Conditional_Waveform_Chain, + Set_Chain_Start => Set_Conditional_Waveform_Chain); + + package Selected_Waveform_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Selected_Waveform_Chain, + Set_Chain_Start => Set_Selected_Waveform_Chain); + + package Association_Choices_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Association_Choices_Chain, + Set_Chain_Start => Set_Association_Choices_Chain); + + package Case_Statement_Alternative_Chain_Handling is new Iir_Chain_Handling + (Get_Chain_Start => Get_Case_Statement_Alternative_Chain, + Set_Chain_Start => Set_Case_Statement_Alternative_Chain); + + -- Return the number of elements in a chain starting with FIRST. + -- Not very efficient since O(N). + function Get_Chain_Length (First : Iir) return Natural; + + -- These two subprograms can be used to build a sub-chain. + -- FIRST and LAST designates respectively the first and last element of + -- the sub-chain. + + -- Set FIRST and LAST to Null_Iir. + procedure Sub_Chain_Init (First, Last : out Iir); + pragma Inline (Sub_Chain_Init); + + -- Append element EL to the sub-chain. + procedure Sub_Chain_Append (First, Last : in out Iir; El : Iir); + pragma Inline (Sub_Chain_Append); + + -- Return TRUE iff CHAIN is of length one, ie CHAIN is not NULL_IIR + -- and chain (CHAIN) is NULL_IIR. + function Is_Chain_Length_One (Chain : Iir) return Boolean; + pragma Inline (Is_Chain_Length_One); + + -- Insert EL after LAST. + procedure Insert (Last : Iir; El : Iir); + + -- Insert EL after LAST and set LAST to EL. + procedure Insert_Incr (Last : in out Iir; El : Iir); +end Iir_Chains; |