Mercurial > hg > CbC > CbC_gcc
diff gcc/ada/sem_dim.ads @ 111:04ced10e8804
gcc 7
author | kono |
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date | Fri, 27 Oct 2017 22:46:09 +0900 |
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children | 84e7813d76e9 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/ada/sem_dim.ads Fri Oct 27 22:46:09 2017 +0900 @@ -0,0 +1,234 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ D I M -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2011-2017, 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 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 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. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides support for numerical systems with dimensions. A +-- "dimension" is a compile-time property of a numerical type which represents +-- a relation between various quantifiers such as length, velocity, etc. + +-- Package System.Dim.Mks offers a ready-to-use system of SI base units. In +-- addition, the implementation of this feature offers the ability to define +-- an arbitrary system of units through the use of Ada 2012 aspects. + +-- Dimensionality checking is part of type analysis performed by the compiler. +-- It ensures that manipulation of quantified numeric values is sensible with +-- respect to the system of units. + +----------------------------- +-- Aspect_Dimension_System -- +----------------------------- + +-- In order to enable the user to create their own dimension system, a new +-- aspect: Aspect_Dimension_System has been created. + +-- Note that this aspect applies for type declaration of type derived from any +-- numeric type. + +-- It defines the names of each dimension + +---------------------- +-- Aspect_Dimension -- +---------------------- + +-- This new aspect applies for subtype and object declarations in order to +-- define new dimensions. + +-- Using this aspect, the user is able to create new subtype/object with any +-- dimension needed. + +-- Note that the base type of the subtype/object must be the type that defines +-- the corresponding dimension system. + +-- The expression of this aspect is an aggregate of rational values for each +-- dimension in the corresponding dimension system. + +------------------------------------------- +-- Dimensionality checking & propagation -- +------------------------------------------- + +-- For each node (when needed), a dimension analysis (Analyze_Dimension) is +-- performed as part of the Resolution routine or the Analysis routine if no +-- Resolution. + +-- The dimension analysis is divided into two phases: + +-- Phase 1: dimension checking + +-- Phase 2: propagation of dimensions + +-- Depending on the node kind, either none, one phase or two phases are +-- executed. + +-- Phase 2 is called only when the node allows a dimension (see body of +-- Sem_Dim to get the list of nodes that permit dimensions). + +-- In principle every node that is a component of a floating-point expression +-- may have a dimension vector. However, the dimensionality checking is for +-- the most part a bottom-up tree traversal, and the dimensions of operands +-- become irrelevant once the dimensions of an operation have been computed. +-- To minimize space use, the dimensions of operands are removed after the +-- computation of the dimensions of the parent operation. This may complicate +-- the analysis of nodes that have been constant-folded or otherwise rewritten +-- when removing side effects. In such cases, the (sub)type of the expression +-- is used to determine the applicable dimensions. + +with Types; use Types; + +package Sem_Dim is + + procedure Analyze_Aspect_Dimension + (N : Node_Id; + Id : Entity_Id; + Aggr : Node_Id); + -- Analyze the contents of aspect Dimension. Associate the provided values + -- and quantifiers with the related context N. Id is the corresponding + -- Aspect_Id (Aspect_Dimension) Aggr is the corresponding expression for + -- the aspect Dimension declared by the declaration of N. + + procedure Analyze_Aspect_Dimension_System + (N : Node_Id; + Id : Entity_Id; + Aggr : Node_Id); + -- Analyze the contents of aspect Dimension_System. Extract the numerical + -- type, unit name and corresponding symbol from each indivitual dimension. + -- Id is the corresponding Aspect_Id (Aspect_Dimension_System). Aggr is + -- the corresponding expression for the aspect Dimension_System from the + -- declaration of N. + + procedure Analyze_Dimension (N : Node_Id); + -- N may denote any of the following contexts: + -- * aggregate + -- * assignment statement + -- * attribute reference + -- * binary operator + -- * call + -- * compontent declaration + -- * extended return statement + -- * expanded name + -- * explicit dereference + -- * identifier + -- * indexed component + -- * number declaration + -- * object declaration + -- * object renaming declaration + -- * procedure call statement + -- * qualified expression + -- * selected component + -- * simple return statement + -- * slice + -- * subtype declaration + -- * type conversion + -- * unary operator + -- * unchecked type conversion + -- Depending on the context, ensure that all expressions and entities + -- involved do not violate the rules of a system. + + procedure Analyze_Dimension_Array_Aggregate + (N : Node_Id; + Comp_Typ : Entity_Id); + -- Check, for each component of the array aggregate denoted by N, the + -- dimensions of the component expression match the dimensions of the + -- component type Comp_Typ. + + procedure Analyze_Dimension_Call (N : Node_Id; Nam : Entity_Id); + -- This routine is split in two steps. Note the second step applies only to + -- function calls. + -- Step 1. Dimension checking: + -- * General case: check the dimensions of each actual parameter match + -- the dimensions of the corresponding formal parameter. + -- * Elementary function case: check each actual is dimensionless except + -- for Sqrt call. + -- Step 2. Dimension propagation (only for functions): + -- * General case: propagate the dimensions from the returned type to the + -- function call. + -- * Sqrt case: the resulting dimensions equal to half the dimensions of + -- the actual + + procedure Analyze_Dimension_Extension_Or_Record_Aggregate (N : Node_Id); + -- Check, for each component of the extension or record aggregate denoted + -- by N, the dimensions of the component expression match the dimensions of + -- the component type. + + procedure Analyze_Dimension_Formals (N : Node_Id; Formals : List_Id); + -- For sub spec N, issue a warning for each dimensioned formal with a + -- literal default value in the list of formals Formals. + + procedure Check_Expression_Dimensions + (Expr : Node_Id; + Typ : Entity_Id); + -- Compute dimensions of a floating-point expression and compare them with + -- the dimensions of a the given type. Used to verify dimensions of the + -- components of a multidimensional array type, for which components are + -- typically themselves arrays. The resolution of such arrays delays the + -- resolution of the ultimate components to a separate phase, which forces + -- this separate dimension verification. + + procedure Copy_Dimensions (From : Node_Id; To : Node_Id); + -- Copy dimension vector of node From to node To. Note that To must be a + -- node that is allowed to contain a dimension (see OK_For_Dimension in + -- body of Sem_Dim). + + procedure Copy_Dimensions_Of_Components (Rec : Entity_Id); + -- Propagate the dimensions of the components of a record type T to the + -- components of a record type derived from T. The derivation creates + -- a full copy of the type declaration of the parent, and the dimension + -- information of individual components must be transferred explicitly. + + function Dimensions_Match (T1 : Entity_Id; T2 : Entity_Id) return Boolean; + -- If the common base type has a dimension system, verify that two + -- subtypes have the same dimensions. Used for conformance checking. + + procedure Eval_Op_Expon_For_Dimensioned_Type + (N : Node_Id; + Btyp : Entity_Id); + -- Evaluate the Expon operator for dimensioned type with rational exponent. + -- Indeed the regular Eval_Op_Expon routine (see package Sem_Eval) is + -- restricted to Integer exponent. This routine deals only with rational + -- exponent which is not an integer if Btyp is a dimensioned type. + + procedure Expand_Put_Call_With_Symbol (N : Node_Id); + -- Determine whether N denotes a subprogram call to one of the routines + -- defined in System.Dim.Float_IO or System.Dim.Integer_IO and add an + -- extra actual to the call to represent the symbolic representation of + -- a dimension. + + function Has_Dimension_System (Typ : Entity_Id) return Boolean; + -- Return True if type Typ has aspect Dimension_System applied to it + + function Is_Dim_IO_Package_Instantiation (N : Node_Id) return Boolean; + -- Return True if N is a package instantiation of System.Dim.Integer_IO or + -- of System.Dim.Float_IO. + + function New_Copy_Tree_And_Copy_Dimensions + (Source : Node_Id; + Map : Elist_Id := No_Elist; + New_Sloc : Source_Ptr := No_Location; + New_Scope : Entity_Id := Empty) return Node_Id; + -- Same as New_Copy_Tree (defined in Sem_Util), except that this routine + -- also copies the dimensions of Source to the returned node. + + procedure Remove_Dimension_In_Statement (Stmt : Node_Id); + -- Remove the dimensions associated with Stmt + +end Sem_Dim;