如何使用我從源代碼構建的庫而沒有錯誤，但不能為我自己的項目編譯？

Question

我想試試AsmJit 庫。 用'cmake'和'make'從源代碼構建它是沒有問題的，它提供的例子都被完美地編譯和執行。 我也做了make install來導出依賴文件。

然后我想使用這個庫編譯我自己的程序，所以我檢索了生成的文件（頭文件和 static 庫），將它們添加到一個新項目中，其代碼是庫網站上給出的第一個示例的復制/粘貼：

// #define ASMJIT_NO_DEPRECATED // this line is no part of the original code
#include <asmjit/asmjit.h>
#include <stdio.h>

using namespace asmjit;

// Signature of the generated function.
typedef int (*Func)(void);

int main(int argc, char* argv[]) {
  JitRuntime rt;                          // Runtime designed for JIT code execution.

  CodeHolder code;                        // Holds code and relocation information.
  code.init(rt.environment());            // Initialize CodeHolder to match JIT environment.

  x86::Assembler a(&code);                // Create and attach x86::Assembler to `code`.
  a.mov(x86::eax, 1);                     // Move one to 'eax' register.
  a.ret();                                // Return from function.
  // ----> x86::Assembler is no longer needed from here and can be destroyed <----

  Func fn;
  Error err = rt.add(&fn, &code);         // Add the generated code to the runtime.
  if (err) return 1;                      // Handle a possible error returned by AsmJit.
  // ----> CodeHolder is no longer needed from here and can be destroyed <----

  int result = fn();                      // Execute the generated code.
  printf("%d\n", result);                 // Print the resulting "1".

  // All classes use RAII, all resources will be released before `main()` returns,
  // the generated function can be, however, released explicitly if you intend to
  // reuse or keep the runtime alive, which you should in a production-ready code.
  rt.release(fn);

  return 0;
}

這是我的測試項目的層次結構：

include\
    asmjit\    // The generated headers from the library build
libasmjit.a    // The generated static library from the library build
main.cpp       // My program's code, as pasted above

這是用於編譯的命令行：

g++ main.cpp -o main -Iinclude -L -lasmjit

出現第一個編譯錯誤：

In file included from include/asmjit/./core.h:2008,
                 from include/asmjit/asmjit.h:27,
                 from main.cpp:1:
include/asmjit/././core/builder.h:375:20: error: function 'asmjit::Error asmjit::BaseBuilder::dump(asmjit::String&, uint32_t) const' definition is marked dllimport
  375 |   ASMJIT_API Error dump(String& sb, uint32_t formatFlags = 0) const noexcept {
      |                    ^~~~

在對 lib 代碼進行一些研究之后，定義ASMJIT_NO_DEPRECATED宏（參見上面的代碼，第一個注釋行）可以防止重現此錯誤。 我懷疑這是一個好主意，因為它可能是以下下一個鏈接錯誤的原因：

C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x35): undefined reference to `__imp__ZN6asmjit10JitRuntimeC1EPKNS_12JitAllocator12CreateParamsE'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x45): undefined reference to `__imp__ZN6asmjit10CodeHolderC1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x6e): undefined reference to `__imp__ZN6asmjit10CodeHolder4initERKNS_11EnvironmentEy'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x82): undefined reference to `__imp__ZN6asmjit3x869AssemblerC1EPNS_10CodeHolderE'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x11f): undefined reference to `__imp__ZN6asmjit3x869AssemblerD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x12f): undefined reference to `__imp__ZN6asmjit10CodeHolderD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x142): undefined reference to `__imp__ZN6asmjit10JitRuntimeD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x159): undefined reference to `__imp__ZN6asmjit3x869AssemblerD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x169): undefined reference to `__imp__ZN6asmjit10CodeHolderD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text+0x17c): undefined reference to `__imp__ZN6asmjit10JitRuntimeD1Ev'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text$_ZN6asmjit11BaseEmitter4emitIJRKNS_3x862GpEiEEEjjDpOT_[_ZN6asmjit11BaseEmitter4emitIJRKNS_3x862GpEiEEEjjDpOT_]+0x4c): undefined reference to `__imp__ZN6asmjit11BaseEmitter6_emitIEjRKNS_8Operand_ES3_'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\<my user name>\AppData\Local\Temp\cc4WaQ7J.o:main.cpp:(.text$_ZN6asmjit11BaseEmitter4emitIJEEEjjDpOT_[_ZN6asmjit11BaseEmitter4emitIJEEEjjDpOT_]+0x1b): undefined reference to `__imp__ZN6asmjit11BaseEmitter6_emitIEj'
collect2.exe: error: ld returned 1 exit status

除了定義這個宏，我找不到防止第一個錯誤發生的方法，而且我也不明白為什么鏈接編輯器找不到引用。 我還嘗試將這些依賴項（頭文件 + static lib）放在適當的 MinGW 目錄（即全局include和lib目錄）中，但這不會改變任何內容。

我如何編譯這個程序，這很簡單？ 我也想知道為什么我所做的沒有奏效，知道了這個錯誤的原因，我將來可能能夠處理相同風格的其他人。

PS：我在管理 C 和 C++ 中的外部依賴項方面沒有太多經驗。 我在 Windows 下，使用 MinGW 和 GCC 的最新版本。

Answer 1

您缺少ASMJIT_STATIC編譯時定義 - 如果您靜態使用 AsmJit，則必須定義它。 AsmJit 在編譯時檢查此定義以設置ASMJIT_API宏，該宏擴展為特定於編譯器的導入/導出/可見性屬性。

AsmJit 文檔（構建說明部分）說 [1]：

靜態使用 AsmJit 的項目必須在所有使用 AsmJit 的編譯單元中定義 ASMJIT_STATIC，否則 AsmJit 會在 ASMJIT_API 裝飾器中使用動態庫導入。 建議以這種方式在使用 AsmJit 的整個項目中定義此宏。

因此，在您的特定情況下，這應該可以解決問題：

g++ main.cpp -o main -Iinclude -L. -lasmjit -DASMJIT_STATIC

注意：文檔鏈接特意鏈接到索引頁面，因此一旦重新組織文檔，它就不會成為死鏈接。

[1] https://asmjit.com/doc/index.html