Ada-提出可访问性检查
我已从Github下载了此程序： 我尝试了第一个例子，但我遇到了一个例外。如果有人能让我深入了解这一点，我将不胜感激。我在这个问题上被难住了很长时间，我真的很想让它发挥作用 我收到的错误是：引发的程序错误：waves.adb:110可访问性检查失败 以下是主文件：Ada-提出可访问性检查,ada,gnat,ada2012,ada95,Ada,Gnat,Ada2012,Ada95,我已从Github下载了此程序： 我尝试了第一个例子，但我遇到了一个例外。如果有人能让我深入了解这一点，我将不胜感激。我在这个问题上被难住了很长时间，我真的很想让它发挥作用 我收到的错误是：引发的程序错误：waves.adb:110可访问性检查失败 以下是主文件： with Waves; use Waves; with Write_To_Stdout; procedure Main is Sine_Gen : constant access Sine_Generator :=
with Waves; use Waves;
with Write_To_Stdout;
procedure Main is
Sine_Gen : constant access Sine_Generator := Create_Sine (Fixed (440.0));
begin
Write_To_Stdout (Sine_Gen);
end Main;
with Effects; use Effects;
with Interfaces; use Interfaces;
package body Waves is
function Mod_To_Int (A : Unsigned_32) return Integer_32;
-------------------
-- Update_Period --
-------------------
procedure Update_Period
(Self : in out Wave_Generator'Class; Buffer : in out Period_Buffer)
is
begin
Self.Frequency_Provider.Next_Samples (Buffer);
for I in Buffer'Range loop
Buffer (I) :=
Utils.Period_In_Samples
(Frequency (Buffer (I)));
end loop;
end Update_Period;
------------
-- Create --
------------
function Create_Saw
(Freq_Provider : Generator_Access) return access Saw_Generator
is
begin
return new Saw_Generator'(Frequency_Provider => Freq_Provider,
Current => -1.0, others => <>);
end Create_Saw;
-----------------
-- Next_Sample --
-----------------
overriding procedure Next_Samples
(Self : in out Saw_Generator; Buffer : in out Generator_Buffer)
is
P_Buffer : Period_Buffer;
begin
Update_Period (Self, P_Buffer);
for I in Buffer'Range loop
Self.Step := 2.0 / Float (P_Buffer (I));
Self.Current := Self.Current + Sample (Self.Step);
if Self.Current > 1.0 then
Self.Current := Self.Current - 2.0;
end if;
Buffer (I) := Self.Current;
end loop;
end Next_Samples;
------------
-- Create --
------------
function Create_Square
(Freq_Provider : access Generator'Class) return access Square_Generator is
begin
return new Square_Generator'(Frequency_Provider =>
Generator_Access (Freq_Provider),
Is_High => True,
Current_Sample => 0,
others => <>);
end Create_Square;
-----------------
-- Next_Sample --
-----------------
overriding procedure Next_Samples
(Self : in out Square_Generator; Buffer : in out Generator_Buffer)
is
P_Buffer : Period_Buffer;
begin
Update_Period (Self, P_Buffer);
for I in Buffer'Range loop
Self.Current_Sample := Self.Current_Sample + 1;
declare
A : constant Period := Period (Self.Current_Sample)
/ P_Buffer (I);
begin
if A >= 1.0 then
Self.Current_Sample := 0;
Buffer (I) := 1.0;
end if;
Buffer (I) := (if A >= 0.5 then 1.0 else -1.0);
end;
end loop;
end Next_Samples;
------------
-- Create --
------------
function Create_Sine
(Freq_Provider : access Generator'Class) return access Sine_Generator
is
Ret : constant access Sine_Generator :=
new Sine_Generator'(Frequency_Provider =>
Generator_Access (Freq_Provider),
Current_Sample => 0,
Current_P => 0.0,
others => <>);
begin
Ret.Current_P := 0.0;
return Ret;
end Create_Sine;
-----------------
-- Next_Sample --
-----------------
overriding procedure Next_Samples
(Self : in out Sine_Generator; Buffer : in out Generator_Buffer)
is
P_Buffer : Period_Buffer;
begin
Update_Period (Self, P_Buffer);
for I in Buffer'Range loop
Self.Current_Sample := Self.Current_Sample + 1;
if Period (Self.Current_Sample) >= Self.Current_P then
Self.Current_P := P_Buffer (I) * 2.0;
Self.Current_Sample := 0;
end if;
Buffer (I) :=
Sample
(Sin
(Float (Self.Current_Sample)
/ Float (Self.Current_P) * Pi * 2.0));
end loop;
end Next_Samples;
------------
-- Create --
------------
function Create_Chain
(Gen : access Generator'Class;
Sig_Procs : Signal_Processors
:= No_Signal_Processors) return access Chain
is
Ret : constant access Chain :=
new Chain'(Gen => Generator_Access (Gen), others => <>);
begin
for P of Sig_Procs loop
Ret.Add_Processor (P);
end loop;
return Ret;
end Create_Chain;
-------------------
-- Add_Processor --
-------------------
procedure Add_Processor
(Self : in out Chain; P : Signal_Processor_Access) is
begin
Self.Processors (Self.Nb_Processors) := P;
Self.Nb_Processors := Self.Nb_Processors + 1;
end Add_Processor;
-----------------
-- Next_Sample --
-----------------
overriding procedure Next_Samples
(Self : in out Chain; Buffer : in out Generator_Buffer)
is
S : Sample;
begin
Self.Gen.Next_Samples (Buffer);
for J in Buffer'Range loop
S := Buffer (J);
for I in 0 .. Self.Nb_Processors - 1 loop
S := Self.Processors (I).Process (S);
end loop;
Buffer (J) := S;
end loop;
end Next_Samples;
---------
-- LFO --
---------
function LFO (Freq : Frequency; Amplitude : Float) return Generator_Access
is
Sin : constant Generator_Access := Create_Sine (Fixed (Freq));
begin
return new Attenuator'
(Level => Amplitude,
Source => new Transposer'(Source => Sin, others => <>), others => <>);
end LFO;
------------
-- Create --
------------
function Create_ADSR
(Attack, Decay, Release : Millisecond; Sustain : Scale;
Source : access Note_Generator'Class := null) return access ADSR
is
begin
return new ADSR'
(State => Off,
Source => Source,
Attack => Msec_To_Period (Attack),
Decay => Msec_To_Period (Decay),
Release => Msec_To_Period (Release),
Sustain => Sustain,
Current_P => 0, others => <>);
end Create_ADSR;
-----------------
-- Next_Sample --
-----------------
overriding procedure Next_Samples
(Self : in out ADSR; Buffer : in out Generator_Buffer)
is
Ret : Sample;
begin
for I in Buffer'Range loop
case Self.Source.Buffer (I).Kind is
when On =>
Self.Current_P := 0;
Self.State := Running;
when Off =>
Self.State := Release;
Self.Cur_Sustain := Scale (Self.Memo_Sample);
Self.Current_P := 0;
when No_Signal => null;
end case;
Self.Current_P := Self.Current_P + 1;
case Self.State is
when Running =>
if Self.Current_P in 0 .. Self.Attack then
Ret := Exp8_Transfer
(Sample (Self.Current_P) / Sample (Self.Attack));
elsif
Self.Current_P in Self.Attack + 1 .. Self.Attack + Self.Decay
then
Ret :=
Exp8_Transfer
(Float (Self.Decay + Self.Attack - Self.Current_P)
/ Float (Self.Decay));
Ret := Ret
* Sample (1.0 - Self.Sustain)
+ Sample (Self.Sustain);
else
Ret := Sample (Self.Sustain);
end if;
Self.Memo_Sample := Ret;
when Release =>
if Self.Current_P in 0 .. Self.Release then
Ret :=
Exp8_Transfer
(Sample (Self.Release - Self.Current_P)
/ Sample (Self.Release))
* Sample (Self.Cur_Sustain);
else
Self.State := Off;
Ret := 0.0;
end if;
when Off => Ret := 0.0;
end case;
Buffer (I) := Ret;
end loop;
end Next_Samples;
----------------------
-- Next_Sample --
----------------------
overriding procedure Next_Samples
(Self : in out Pitch_Gen; Buffer : in out Generator_Buffer)
is
Ret : Sample;
begin
if Self.Proc /= null then
Self.Proc.Next_Samples (Buffer);
end if;
for I in Buffer'Range loop
case Self.Source.Buffer (I).Kind is
when On =>
Self.Current_Note := Self.Source.Buffer (I).Note;
Self.Current_Freq :=
Note_To_Freq (Self.Current_Note, Self.Relative_Pitch);
when others => null;
end case;
Ret := Sample (Self.Current_Freq);
if Self.Proc /= null then
Ret := Ret + Buffer (I);
end if;
Buffer (I) := Ret;
end loop;
end Next_Samples;
------------------
-- Create_Noise --
------------------
function Create_Noise return access Noise_Generator
is
N : constant access Noise_Generator := new Noise_Generator;
begin
return N;
end Create_Noise;
F_Level : constant Sample := 2.0 / Sample (16#FFFFFFFF#);
G_X1 : Unsigned_32 := 16#67452301#;
G_X2 : Unsigned_32 := 16#EFCDAB89#;
Z : constant := 2 ** 31;
----------------
-- Mod_To_Int --
----------------
function Mod_To_Int (A : Unsigned_32) return Integer_32 is
Res : Integer_32;
begin
if A < Z then
return Integer_32 (A);
else
Res := Integer_32 (A - Z);
Res := Res - (Z - 1) - 1;
return Res;
end if;
end Mod_To_Int;
------------------
-- Next_Samples --
------------------
overriding procedure Next_Samples
(Self : in out Noise_Generator; Buffer : in out Generator_Buffer)
is
pragma Unreferenced (Self);
begin
for I in Buffer'Range loop
G_X1 := G_X1 xor G_X2;
Buffer (I) := Sample (Mod_To_Int (G_X2)) * F_Level;
G_X2 := G_X2 + G_X1;
end loop;
end Next_Samples;
------------------
-- Next_Samples --
------------------
overriding procedure Next_Samples
(Self : in out Fixed_Gen; Buffer : in out Generator_Buffer) is
begin
if Self.Proc /= null then
Self.Proc.Next_Samples (Buffer);
for I in Buffer'Range loop
Buffer (I) := Self.Val + Buffer (I);
end loop;
else
for I in Buffer'Range loop
Buffer (I) := Self.Val;
end loop;
end if;
end Next_Samples;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out ADSR) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Source);
Self.Memo_Sample := 0.0;
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Saw_Generator) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Frequency_Provider);
Self.Current := -1.0;
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Square_Generator) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Frequency_Provider);
Self.Current_Sample := 0;
Self.Is_High := True;
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Sine_Generator) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Frequency_Provider);
Self.Current_Sample := 0;
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Noise_Generator) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Frequency_Provider);
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Pitch_Gen) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Source);
Reset_Not_Null (Self.Proc);
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Fixed_Gen) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Proc);
end Reset;
-----------
-- Reset --
-----------
overriding procedure Reset (Self : in out Chain) is
begin
Base_Reset (Self);
Reset_Not_Null (Self.Gen);
end Reset;
-----------
-- Fixed --
-----------
function Fixed
(Freq : Frequency;
Modulator : Generator_Access := null;
Name : String := "";
Min : Float := 0.0;
Max : Float := 5_000.0;
Param_Scale : Param_Scale_T := Linear)
return access Fixed_Gen
is
begin
return new
Fixed_Gen'
(Val => Sample (Freq),
Proc => Modulator,
Name => To_Unbounded_String (Name),
Min => Min,
Max => Max,
Param_Scale => Param_Scale,
others => <>);
end Fixed;
---------------
-- Set_Value --
---------------
overriding procedure Set_Value
(Self : in out Fixed_Gen; I : Natural; Val : Float)
is
pragma Unreferenced (I);
begin
Self.Val := Sample (Val);
end Set_Value;
---------------
-- Set_Value --
---------------
overriding procedure Set_Value
(Self : in out ADSR; I : Natural; Val : Float)
is
begin
case I is
when 0 => Self.Attack := Sec_To_Period (Val);
when 1 => Self.Decay := Sec_To_Period (Val);
when 2 => Self.Sustain := Scale (Val);
when 3 => Self.Release := Sec_To_Period (Val);
when others => raise Constraint_Error;
end case;
end Set_Value;
end Waves;
劳埃德有关功能：
function Create_Sine
(Freq_Provider : access Generator'Class) return access Sine_Generator
is
Ret : constant access Sine_Generator :=
new Sine_Generator'(Frequency_Provider =>
Generator_Access (Freq_Provider),
Current_Sample => 0,
Current_P => 0.0,
others => <>);
begin
Ret.Current_P := 0.0;
return Ret;
end Create_Sine;
function Create_Sine
(Freq_Provider : access Generator'Class) return access Sine_Generator
is
begin
return Ret : constant access Sine_Generator :=
new Sine_Generator'( Frequency_Provider =>
Generator_Access (Freq_Provider),
Current_Sample => 0,
Current_P => 0.0,
others => <>)
do
-- initialisation actions here
Ret.Current_P := 0.0;
end return;
end Create_Sine;
总的来说，这个问题可能有更好的答案。我刚刚谈到了当前的问题，但更广泛的问题是，这里是否需要访问类型？在Ada中，答案通常是否定的，但并不总是否定的。在许多情况下，来自其他语言的程序员只是在Ada中有一种更简单或更好的方法来做事情时，才去寻找指针。所讨论的函数：
function Create_Sine
(Freq_Provider : access Generator'Class) return access Sine_Generator
is
Ret : constant access Sine_Generator :=
new Sine_Generator'(Frequency_Provider =>
Generator_Access (Freq_Provider),
Current_Sample => 0,
Current_P => 0.0,
others => <>);
begin
Ret.Current_P := 0.0;
return Ret;
end Create_Sine;
function Create_Sine
(Freq_Provider : access Generator'Class) return access Sine_Generator
is
begin
return Ret : constant access Sine_Generator :=
new Sine_Generator'( Frequency_Provider =>
Generator_Access (Freq_Provider),
Current_Sample => 0,
Current_P => 0.0,
others => <>)
do
-- initialisation actions here
Ret.Current_P := 0.0;
end return;
end Create_Sine;
总的来说，这个问题可能有更好的答案。我刚刚谈到了当前的问题，但更广泛的问题是，这里是否需要访问类型？在Ada中，答案通常是否定的，但并不总是否定的。在许多情况下，来自其他语言的程序员只是在Ada中找到了一种更简单或更好的方法来完成任务。您使用的是哪种编译器版本和哪些选项？我这样问是因为我得到了很多关于访问类型的警告，但没有程序错误。main.adb是您自己的来源吗？我一点也不确定你所说的第一个例子是什么意思，因为原始回购协议没有提到这一点。嘿，西蒙，谢谢你的回复。我使用的是GNAT社区版的最新版本。抱歉，我不清楚这些例子。示例如下：-第一个示例是simple_sine.adb-在我的初始问题中，这是我放在主文件中的代码。再看一看。事实证明，ada_synth_lib.gpr中的默认版本选项调用in-gnatp，这意味着抑制所有检查。在国际海事组织，这是一个永远不应该使用的选项，除非您处于极端的性能压力下，并且在证明不会触发检查之后。就像在赛前准备过程中虔诚地系上安全带后，在出发参加公路赛时脱下安全带一样。感谢您查看本手册，西蒙，我已经记下永远不要使用-gnatp选项。我将在程序中保留此功能，并修改代码。感谢you@Simon：这就解释了为什么OP在发布的代码中发现了这个问题，这一直是个谜
你在使用哪个编译器版本和什么选项？我这样问是因为我得到了很多关于访问类型的警告，但没有程序错误。main.adb是您自己的来源吗？我一点也不确定你所说的第一个例子是什么意思，因为原始回购协议没有提到这一点。嘿，西蒙，谢谢你的回复。我使用的是GNAT社区版的最新版本。抱歉，我不清楚这些例子。示例如下：-第一个示例是simple_sine.adb-在我的初始问题中，这是我放在主文件中的代码。再看一看。事实证明，ada_synth_lib.gpr中的默认版本选项调用in-gnatp，这意味着抑制所有检查。在国际海事组织，这是一个永远不应该使用的选项，除非您处于极端的性能压力下，并且在证明不会触发检查之后。就像在赛前准备过程中虔诚地系上安全带后，在出发参加公路赛时脱下安全带一样。感谢您查看本手册，西蒙，我已经记下永远不要使用-gnatp选项。我将在程序中保留此功能，并修改代码。感谢you@Simon：这就是为什么OP在发布的代码中发现了这个问题，这一直困扰着我。Brain，非常感谢。这就解决了问题。感谢您花时间阅读本文，并提供awnser。我已经测试了你的解决方案，它是有效的。我现在将花时间研究这是如何解决这个问题的。再次感谢Brian:Hi@Brian再次感谢您的回复，在我完成这项工作的同时，我已经使用您的解决方案解决了一些其他功能的可访问性检查。然而，我现在遇到的是一个过程，而不是一个函数，这让我再次感到困惑！过程寄存器\u模拟\u侦听器N:access I\u模拟\u侦听器的类是begin Simulation\u Listeners Simulation\u Listeners\u Nb:=N；模拟侦听器\u Nb:=模拟侦听器\u Nb+1；结束寄存器\模拟\侦听器；你好，劳埃德，准确的误差是。。。？你有没有办法把这个错误的最小复制者作为一个新的问题？谢谢Brian，我已经在这里回复了这个问题：Brain，非常感谢。这就解决了问题。感谢您花时间阅读本文，并提供awnser。我已经测试了你的解决方案，它是有效的。我现在将花时间研究这是如何解决这个问题的。再次感谢Brian:Hi@Brian再次感谢您的回复，在我完成这项工作的同时，我已经使用您的解决方案解决了一些其他功能的可访问性检查。然而，我现在遇到的是一个过程，而不是一个函数，这让我再次感到困惑！过程寄存器\u模拟\u侦听器N:access I\u模拟\u侦听器的类是begin Simulation\u Listeners Simulation\u Listeners\u Nb:=N；模拟侦听器\u Nb:=模拟侦听器\u Nb+1；结束寄存器\模拟\侦听器；你好，劳埃德，准确的误差是。。。？你有什么办法可以把这个错误的最小复制者组合起来作为一个新问题吗？谢谢Brian，我已经在这里重新提出了这个问题：