The original post is here, thanks to this author
The error message is similar to
message.h:36:16: error: redefinition of 'struct MSG_SERVOCTRL'
message.h:36:16: note: originally defined here
message.h:40:2: error: conflicting types for 'servoctrl'
message.h:40:2: note: previous declaration of 'servoctrl' was here
message.h:42:16: error: redefinition of 'struct MSG_PTZCTRL'
message.h:42:16: note: originally defined here
message.h:51:2: error: conflicting types for 'ptzctrl'
message.h:51:2: note: previous declaration of 'ptzctrl' was here
message.h:55:20: error: redefinition of 'cameractrl_params'
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Generally, the target header file.h does not have conditional compilation statements, and the format of the statement is relatively fixed:
#ifndef _TEST_H_
#define _TEST_H_
//。。。
#endif
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Add the above code to the beginning and end of the header file.h to avoid repeated definition errors.
#include "" is actually expanding the content of the .h file before spreading it in the .c file. If there is no conditional compilation, then repeat reference and looprecursionWhen include, multiple duplicate definitions will be expanded before the .c code, so there will inevitably be a duplicate definition alarm when compiling.