dll构建中的初始化代码在导入时不会自动运行。我做了一个由:
组成的mcvedistric.ads
with System;
with Interfaces.C;
package Division is
--Neither of these work
procedure DllMainCRTStartup ;
pragma Export (StdCall, DllMainCRTStartup , "DllMainCRTStartup"); --Edited as noticed by Brian
-- procedure DllMain
-- pragma Export (StdCall, DllMain , "DllMain ");
function Div (A : in INTEGER; B : in INTEGER) return INTEGER;
pragma Export (C, Div, "MyDivision");
-- --If I put this, it does not compile... maybe a wrong linkage option set?
-- procedure AdaInit;
-- pragma Import (C, AdaInit, "adainit");
end Division;
distric.adb
with text_io;
package body Division is
procedure DllMainCRTStartup is begin --DllMain or DllMainCRTStartup
text_io.put("INIT CODE YEAH!!!*************!"); --This does not execute :(
--AdaInit;
end DllMainCRTStartup ;
function Div(A : in INTEGER; B : in INTEGER) return INTEGER is
X : INTEGER := A/B;
begin
return X;
end Div;
end Division;
和GPR:
library project Proj_Name is
for Library_Name use "math";
for Object_Dir use "obj";
for Source_Dirs use ("src");
for Library_Dir use "lib";
for Library_Interface use ("Division");
for Library_Kind use "dynamic";
for Library_Options use ("-LC:GNAT2015libgcci686-pc-mingw324.9.3adalib",
"-LC:GNAT2015libgcci686-pc-mingw324.9.3adaliblibgnat");
end Proj_Name;
我正在用CTYPES测试Python的DLL。我用ctypes.cdll导入它,并且可以使用myDivision。但是,导入DLL时未运行INIT代码,因为未执行text_io。
另一方面,如果我在代码中添加Adainit过程,则在编译时会得到这样的东西:
undefined reference to `adainit'
非常感谢!
我不确定您如何知道未运行初始化代码?
我在MacOS上运行,但是ADA方面应该相似。我将此包装/主体写为您的简单版本:
package Division is
function Div (A : in INTEGER; B : in INTEGER) return INTEGER;
pragma Export (C, Div, "MyDivision");
end Division;
with Ada.Text_IO;
package body Division is
function Div(A : in INTEGER; B : in INTEGER) return INTEGER is
X : INTEGER := A/B;
begin
return X;
end Div;
procedure Test_For_Elaboration is
begin
Ada.Text_IO.Put_Line ("hello world!");
end Test_For_Elaboration;
begin
Test_For_Elaboration;
end Division;
使用此简单的GPR
library project Proj_Name is
for Library_Name use "math";
for Object_Dir use "obj";
for Source_Dirs use ("src");
for Library_Dir use "lib";
for Library_Interface use ("Division");
for Library_Kind use "dynamic";
end Proj_Name;
并使用此C代码进行了测试:
#include <stdio.h>
extern int MyDivision(int, int);
int main()
{
printf("42 / 2 => %dn", MyDivision(42, 2));
return 0;
}
结果是
$ ./caller
hello world!
42 / 2 => 21
很清楚,对我来说,图书馆精心设计无需我做任何事情。
原因是您在项目文件中指定了Library_Interface
,这意味着您正在构建独立库,
是一个包含必要代码以详细列出库中包含的ADA单元的库。独立的库是一种在更全球的系统中添加ADA子系统的便捷方法,该系统不在ADA中,因为它使ADA部分的详细说明主要是透明的。
您可以使用
来指定一个独立的动态库,该库自动初始化for Library_Auto_Init use "false";
在这种情况下,您需要自己调用图书馆的初始化过程;它称为{library-name}init
(在您的情况下,mathinit
)。但是,您需要从主计划中调用它;需要在C
extern void mathinit();