Pascal单元可以编译为可执行文件吗?

Question

我喜欢我的库同时作为可执行文件。期望的行为是:

$ ./scriptedmain
Main: The meaning of life is: 42
$ ./test
Test: The meaning of life is: 42

如何:

• 获得scriptedmain.p编译成scriptedmain二进制文件?
• 防止test.p运行的代码是在scriptedmain.p的begin/end节?

scriptedmain.p:

unit ScriptedMain;
    interface
    function MeaningOfLife () : integer;
    implementation
    function MeaningOfLife () : integer;
    begin
        MeaningOfLife := 42
    end;
begin
    write('Main: The meaning of life is: ');
    writeln(MeaningOfLife())
end.

当我编译scriptedmain。p与fpc scriptedmain.p，没有可执行文件被创建，因为Pascal检测到它是一个单元。但我希望它是一个可执行文件，而不是一个库。

$ ./scriptedmain
-bash: ./scriptedmain: No such file or directory

test.p:

program Test;
uses
    ScriptedMain;
begin
    write('Test: The meaning of life is: ');
    writeln(MeaningOfLife())
end.

当我编译测试。p和fpc test.p，结果可执行文件结合了两个begin/end声明(不是期望的行为)。

$ ./test 
Main: The meaning of life is: 42
Test: The meaning of life is: 42

Answer 1

我不知道你使用的Pascal是什么味道，但是一些变体支持{$IFC condition} ... {$ENDC}的条件编译。您可以将它与编译时定义结合使用，以包含/排除给定版本中需要或不需要的代码。

Answer 2

感谢Free Pascal邮件列表中的Ager和Zhirov，我能够用最少的技巧构建一个工作的脚本主示例。也发在RosettaCode

Makefile:

all: scriptedmain
scriptedmain: scriptedmain.pas
    fpc -dscriptedmain scriptedmain.pas
test: test.pas scriptedmain
    fpc test.pas
clean:
    -rm test
    -rm scriptedmain
    -rm *.o
    -rm *.ppu

scriptedmain.pas:

{$IFDEF scriptedmain}
program ScriptedMain;
{$ELSE}
unit ScriptedMain;
interface
function MeaningOfLife () : integer;
implementation
{$ENDIF}
    function MeaningOfLife () : integer;
    begin
        MeaningOfLife := 42
    end;
{$IFDEF scriptedmain}
begin
    write('Main: The meaning of life is: ');
    writeln(MeaningOfLife())
{$ENDIF}
end.

test.pas:

program Test;
uses
    ScriptedMain;
begin
    write('Test: The meaning of life is: ');
    writeln(MeaningOfLife())
end.

的例子:

$ make
$ ./scriptedmain 
Main: The meaning of life is: 42
$ make test
$ ./test 
Test: The meaning of life is: 42