Question

如何将FPC .o从库链接到Delphi可执行文件。当我尝试链接以下代码时，我得到了一堆不满意的前向或外部声明。

library project1;

{$mode objfpc}{$H+}

uses
  Classes
  { you can add units after this };

function Test: Integer;
begin
  Result := -1;
end;

begin
end.


[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$SYSTEM'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FINALIZE$_$OBJPAS'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$LNFODWRF'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FINALIZE$_$LNFODWRF'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$FPINTRES'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FINALIZE$_$WINDIRS'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'SYSUTILS$_$TENCODING_$__$$_create'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'SYSUTILS$_$TENCODING_$__$$_destroy'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$SYSUTILS'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FINALIZE$_$SYSUTILS'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$TYPINFO'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FINALIZE$_$TYPINFO'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'INIT$_$CLASSES'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FINALIZE$_$CLASSES'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'THREADVARLIST_$SYSTEM'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'THREADVARLIST_$CLASSES'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'RESSTR_$RTLCONSTS_$$_START'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'RESSTR_$RTLCONSTS_$$_END'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'RESSTR_$SYSCONST_$$_START'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'RESSTR_$SYSCONST_$$_END'
[dcc64 Error] Project2.dpr(170): E2065 Unsatisfied forward or external declaration: 'FPC_LIBINITIALIZEUNITS'

Answer 1

至少在写完之前，你很可能无法完成这项工作。未满足的声明来自FPC运行时。您还需要链接它，或者在Delphi中重新实现它。这两种选择都不太可行。

当然，如果您删除了对Classes单元的引用，并将此简单函数放在单独的代码单元而不是库单元中，那么可能没有不满意的声明是合理的。也就是说，你肯定在探索这个，因为你想使用实际做某事的FPC代码。一旦你这样做，那么你将立即回到原点。

解决此问题的方法是动态链接到FPC代码。将FPC代码编译到库中并动态链接到该库。

为了好玩，我试图将FPC对象链接到Delphi程序。 FPC单位：

unit unit1;

interface

implementation

function Test(i: Integer): Integer; cdecl;
begin
  Test := i*42;
end;

end.

我编译了这个：

fpc unit1.pp

然后我编写了以下Delphi程序来链接它：

{$APPTYPE CONSOLE}

{$L 'unit1.o'}

function Test(i: Integer): Integer; cdecl; 
  external name 'UNIT1_TEST$SMALLINT$$SMALLINT';

begin
  Writeln(Test(666));
end.

输出：

请注意，函数名称已修饰。为了找到我使用objdump的名称：

>objdump -d unit1.o

unit1.o:     file format pe-i386


Disassembly of section .text.n_unit1_test$smallint$$smallint:

00000000 :
   0:   55                      push   %ebp
   1:   89 e5                   mov    %esp,%ebp
   3:   83 ec 04                sub    $0x4,%esp
   6:   0f bf 45 08             movswl 0x8(%ebp),%eax
   a:   6b c0 2a                imul   $0x2a,%eax,%eax
   d:   66 89 45 fc             mov    %ax,-0x4(%ebp)
  11:   66 8b 45 fc             mov    -0x4(%ebp),%ax
  15:   c9                      leave
  16:   c3                      ret
        ...

我使用x86版本的编译器完成了这项工作。我希望它在x64下也可行。

所以你确实可以链接FPC对象文件，只要它们足够简单。但是，如果您需要任何FPC运行时和标准单元，那么我预计它会变得太难。

将FPC .o文件链接到Delphi

1 个答案: