Call C functions from VC++
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Is there any method to call C code from VC++/MFC project ? I need to call some functions from a C project (pretty big project). If I include some files from that C project, I get some error:
precompiled header file is from a previous version of the compiler, or the precompiled header is C++ and you are using it from C (or vice versa)
moreover, I get a lot of unrecongnized types ... to modify types and functions in C project is huge work ... how can I overcome this ? Maybe you have been in the same situaton like me ...
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Is there any method to call C code from VC++/MFC project ? I need to call some functions from a C project (pretty big project). If I include some files from that C project, I get some error:
precompiled header file is from a previous version of the compiler, or the precompiled header is C++ and you are using it from C (or vice versa)
moreover, I get a lot of unrecongnized types ... to modify types and functions in C project is huge work ... how can I overcome this ? Maybe you have been in the same situaton like me ...
Maybe that can help: SO: Compile C files in C++ project which do not use precompiled header?[^] Top-most answer presents some simple workarounds. If there are a lot of .c files in your project, disabling precompiled-headers solution-wide seems appropriate.
enum HumanBool { Yes, No, Maybe, Perhaps, Probably, ProbablyNot, MostLikely, MostUnlikely, HellYes, HellNo, Wtf }
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Maybe that can help: SO: Compile C files in C++ project which do not use precompiled header?[^] Top-most answer presents some simple workarounds. If there are a lot of .c files in your project, disabling precompiled-headers solution-wide seems appropriate.
enum HumanBool { Yes, No, Maybe, Perhaps, Probably, ProbablyNot, MostLikely, MostUnlikely, HellYes, HellNo, Wtf }
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Strange. Maybe there are some leftovers from previous compilation sessions. Did you try to clean the solution and rebuild it completely? Does the error appear for all .c source files, or only for specific one(s)?
enum HumanBool { Yes, No, Maybe, Perhaps, Probably, ProbablyNot, MostLikely, MostUnlikely, HellYes, HellNo, Wtf }
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Is there any method to call C code from VC++/MFC project ? I need to call some functions from a C project (pretty big project). If I include some files from that C project, I get some error:
precompiled header file is from a previous version of the compiler, or the precompiled header is C++ and you are using it from C (or vice versa)
moreover, I get a lot of unrecongnized types ... to modify types and functions in C project is huge work ... how can I overcome this ? Maybe you have been in the same situaton like me ...
It may possibly depend on how you are connecting the two. In general calling C functions from MFC/C++ presents no problems and works out of the box. Maybe if you showed some of the headers that you are including and the associated error messages we may be able to figure something out.
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It may possibly depend on how you are connecting the two. In general calling C functions from MFC/C++ presents no problems and works out of the box. Maybe if you showed some of the headers that you are including and the associated error messages we may be able to figure something out.
I have included C header and fix some errors, but I met another error:
MyDoc.obj : error LNK2019: unresolved external symbol _function1 referenced in function "public: int __thiscall CMyDoc::SomeMethod
MyDoc.obj : error LNK2019: unresolved external symbol _function2 referenced in function "public: int __thiscall CMyDoc::SomeMEthodso, if I included xxx.c file, I got tones of errors ... if I added that file to my project, happen nothing, I mean I got the same errors ... what could be the next step ?
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I have included C header and fix some errors, but I met another error:
MyDoc.obj : error LNK2019: unresolved external symbol _function1 referenced in function "public: int __thiscall CMyDoc::SomeMethod
MyDoc.obj : error LNK2019: unresolved external symbol _function2 referenced in function "public: int __thiscall CMyDoc::SomeMEthodso, if I included xxx.c file, I got tones of errors ... if I added that file to my project, happen nothing, I mean I got the same errors ... what could be the next step ?
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The linker errors are telling you that some file or object is missing from the build. Check where function1 and function2 are defined, and make sure that the file that contains them is included in your project..
Yes, I included, but I got the first error:
precompiled header file is from a previous version of the compiler, or the precompiled header is C++ and you are using it from C (or vice versa)even if I did that settings in my VC++ app, I still have this error ... -
Yes, I included, but I got the first error:
precompiled header file is from a previous version of the compiler, or the precompiled header is C++ and you are using it from C (or vice versa)even if I did that settings in my VC++ app, I still have this error ...You are using a previously built precompiled header so you need to force a complete rebuild of your project to ensure it is recreated with the current compiler and header files. Unfortunately most of this is guesswork as we cannot see the structure of your project(s). As I said earlier, calling C functions from C++ always works if you have the correct header and source/object files included.
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Yes, I included, but I got the first error:
precompiled header file is from a previous version of the compiler, or the precompiled header is C++ and you are using it from C (or vice versa)even if I did that settings in my VC++ app, I still have this error ..._Flaviu wrote:
...even if I did that settings in my VC++ app
What settings?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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_Flaviu wrote:
...even if I did that settings in my VC++ app
What settings?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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It just occurred to me that you are probably suffering from C++ name mangling. You need to add the following lines to the header files of your .c code:
#ifdef __cplusplus // these lines at the beginning of the file before your definitions
extern "C" {
#endif#ifdef __cplusplus // these lines at the end of the file after your definitions
}
#endif