LNK2091 error for OCIObjectGetAttr and OCIObjectSetAttr

0
votes

I have a small Windows x64 Console program statically linked to oci.lib (12.1.0.1.0) which was working well so far until I tried to use the APIs OCIObjectGetAttr/OCIObjectSetAttr. Now my program gives the following Linker errors:

  • Error 19 error LNK2019: unresolved external symbol "int __cdecl OCIObjectSetAttr(struct OCIEnv *,struct OCIError *,void *,void *,struct OCIType *,unsigned char const * *,unsigned int const *,unsigned int,unsigned int const *,unsigned int,short,void const *,void const *)" (?OCIObjectSetAttr@@YAHPEAUOCIEnv@@PEAUOCIError@@PEAX2PEAUOCIType@@PEAPEBEPEBII5IFPEBX6@Z) referenced in function "bool __cdecl dump_object(struct OCIEnv *,struct OCIError *,struct OCISvcCtx *,void *,void *,void *)" (?dump_object@@YA_NPEAUOCIEnv@@PEAUOCIError@@PEAUOCISvcCtx@@PEAX33@Z)

  • Error 20 error LNK2019: unresolved external symbol "int __cdecl OCIObjectGetAttr(struct OCIEnv *,struct OCIError *,void *,void *,struct OCIType *,unsigned char const * *,unsigned int const *,unsigned int,unsigned int const *,unsigned int,short *,void * *,void * *,struct OCIType * *)" (?OCIObjectGetAttr@@YAHPEAUOCIEnv@@PEAUOCIError@@PEAX2PEAUOCIType@@PEAPEBEPEBII5IPEAFPEAPEAX7PEAPEAU3@@Z) referenced in function "bool __cdecl dump_object(struct OCIEnv *,struct OCIError *,struct OCISvcCtx *,void *,void *,void *)" (?dump_object@@YA_NPEAUOCIEnv@@PEAUOCIError@@PEAUOCISvcCtx@@PEAX33@Z)

Commenting only those two APIs fixes the linker error. I made sure that nothing in project is changed apart from adding the two OCIObjectGetAttr and OCIObjectSetAttr API calls. Other OCIObject* APIs are linking. dumpbin /exports oci.lib shows that OCIObjectGetAttr and OCIObjectSetAttr are exported from the oci.lib.

What am I missing?

Stuck with this for quite a while. Google/Community search hasn't helped either.

Please help.

TIA

NB: Also posted in OTN (https://community.oracle.com/message/12457198#12457198) Please forgive duplicate posting in desperation

1
cwindowslinker-errorsstatic-linkingoracle-call-interface
Are there any DLLs that the executable requires, or any additional external libraries that provide for those APIs? - Cormac O'Brien
@Ceann +1 for replying. Oracle says either dynamic link with oci.dll or static link with oci.lib. But I am mostly confused from Oracle docs always! - alienfromouterspace
Try linking to oci.dll instead. If that doesn't work, I can't think of anything past redownloading the libraries -- I took a look around and, as you said, it doesn't seem like there are any other libraries that need to be present for this API to work. - Cormac O'Brien
@Ceann I will try dynamic linking to it. But my distribution was static linked. That will need to change if it works that way! - alienfromouterspace
Where did you get your oci.dll from? First, you can only dynamically link to OCI. On Windows, dynamic linking means linking statically oci.lib at build time, which is an "import library", that contains stubs to the OCI API functions, which transparently at runtime loads oci.dll and calls the appropriate function in there. Second, the demangled prototypes show "unsigned int" (ub4) instead of "const unsigned int" as the proto in the header and the doc at goo.gl/UlvpfR show it should be. Could be the demangler just drops the const though. - ddevienne

1 Answers

1
votes

Seems to be a bug in orid.h, the following got me going. I was trying to link from C++ where as orid.h is missing the standard extern "C" block for linking from C++ like other oci header files.

Wrapping the content of orid.h within the following got me successfully compiling.

#ifdef __cplusplus
extern "C" {
#endif
...
#ifdef __cplusplus
}
#endif /* __cplusplus */

Hope Oracle fixes it in their next instant client release :).

Thanks to Ceann and ddevienne for helping me to narrow down.