項目編譯報出如下錯誤:
Pcre.obj:error LNK2001:無法解析的外部符號 __imp__pcre_free
Pcre.obj:error LNK2001:無法解析的外部符號 __imp__pcre_compile
Pcre.obj:error LNK2001:無法解析的外部符號 __imp__pcre_exec解決辦法是在頭文件的最開頭加上宏定義#define PCRE_STATIC
疑問:爲什麼必須在其他#include之前呢？
請看pcre.h中48-66行
/* When an application links to a PCRE DLL in Windows, the symbols that are
imported have to be identified as such. When building PCRE, the appropriate
export setting is defined in pcre_internal.h, which includes this file. So we
don't change existing definitions of PCRE_EXP_DECL and PCRECPP_EXP_DECL. */
#if defined(_WIN32) && !defined(PCRE_STATIC)
# ifndef PCRE_EXP_DECL
# define PCRE_EXP_DECL extern __declspec(dllimport)
# endif
# ifdef __cplusplus
# ifndef PCRECPP_EXP_DECL
# define PCRECPP_EXP_DECL extern __declspec(dllimport)
# endif
# ifndef PCRECPP_EXP_DEFN
# define PCRECPP_EXP_DEFN __declspec(dllimport)
# endif
# endif
#endif參考:
Google it , I found the thread about the error, a comment gives the solutions:
Building under Windows:
If you want to statically link this program against a non-dll .a file, you must
define PCRE_STATIC before including pcre.h, otherwise the pcre_malloc() and
pcre_free() exported functions will be declared __declspec(dllimport), with
unwanted results. So in this environment, uncomment the following line. */
//#define PCRE_STATIC