c - 链接C文件错误: linker command failed with exit code 1

Question

我有三个文件:rsa.c、prf.c 和 rsa-test.c。

我使用gcc -c rsa.c、gcc -c prf.c、gcc -c rsa-test.c来获取.o 文件。

编辑:我将 rsa.c 和 prf.c 包含在 rsa-test.c 中。

然后我使用 gcc -o test rsa.o prf.o rsa-test.o 编译 .o 文件。

编译时出现以下错误。 o 三个文件的文件。

Undefined symbols for architecture x86_64:
  "_EVP_sha512", referenced from:
      randBytes(unsigned char*, unsigned long) in prf.o
  "_HMAC", referenced from:
      randBytes(unsigned char*, unsigned long) in prf.o
  "_SHA512", referenced from:
      setSeed(unsigned char*, unsigned long) in prf.o
  "___gmpz_add_ui", referenced from:
      randBytes(unsigned char*, unsigned long) in prf.o
  "___gmpz_clear", referenced from:
      rsa_shredKey(_RSA_KEY*) in rsa.o
  "___gmpz_export", referenced from:
      zToFile(__sFILE*, __mpz_struct*) in rsa.o
  "___gmpz_import", referenced from:
      zFromFile(__sFILE*, __mpz_struct*) in rsa.o
  "___gmpz_init", referenced from:
      rsa_initKey(_RSA_KEY*) in rsa.o
      setSeed(unsigned char*, unsigned long) in prf.o
  "___gmpz_limbs_read", referenced from:
      randBytes(unsigned char*, unsigned long) in prf.o
  "___gmpz_limbs_write", referenced from:
      rsa_shredKey(_RSA_KEY*) in rsa.o
  "___gmpz_set_ui", referenced from:
      rsa_initKey(_RSA_KEY*) in rsa.o
      setSeed(unsigned char*, unsigned long) in prf.o
  "___gmpz_size", referenced from:
      zToFile(__sFILE*, __mpz_struct*) in rsa.o
      rsa_numBytesN(_RSA_KEY*) in rsa.o
      rsa_shredKey(_RSA_KEY*) in rsa.o
      randBytes(unsigned char*, unsigned long) in prf.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

我不确定是什么导致了这个错误。链接器似乎是问题所在，因为我在 rsa-test.c 中使用 rsa.c 和 prf.c 中的函数，这就是导致此问题的原因。

如果您想测试我的文件，请告诉我，我会将其发布。

Answer 1

您需要通过向 gcc -o 命令添加链接标志来链接到您正在使用的库。

看起来您正在使用 GMP，因此该标志应该是 -lgmp。

如果涉及的其他库是 OpenSSL，请尝试 -lcrypto 或参见 here如果您从源代码构建它。

gcc -o test_linked.exe rsa.o prf.o rsa-test.o -lgmp -lcrypto