Unresolved External Symbol

[StevenCooper]

I recently moved from a Windows 10 computer to a Windows 11 computer; I had previously been using Version 10 of Pelles C, but it wouldn't work in Windows 11, so I "jumped" all the way up to Pelles C Version 14.5.

Two programs I "test" compiled under version 14.5 compiled and linked just fine, no problems.

But a third program, that compiled just fine under version 10, is now getting the following error message under Version 14.5:

POLINK: error: Unresolved external symbol '__stod' - referenced from 'C:\Users\steco\Documents\Pelles C Projects\LotteryScratchOffs\output\LotteryScratchOffs.obj'.

I have searched this forum for information about this, but found only one refernce to it from 12 years ago.

I have also search the Internet and can find no information about this '__stod' symbol.

Can somebody help me, please?

[TimoVJL]

Just search it from a your code.
A macro atof use it in version 10.

Code Select Expand

/* internal stuff */
...
/* macro overrides */
#define atof(s)  __stod(s,0,0)


Code Select Expand

[155]extern _CRTIMP double __cdecl __stod(const char *, char **, long);
[172]#define atof(s)  __stod(s,0,0)
[177]#define strtod(s,endptr)  __stod(s,endptr,0)

[StevenCooper]

One of the first things I did was search my code for a reference to 'stod'; there are none. Next, I checked the help files for information about it...there is none.

You mentioned a macro reference to the atof() function; I looked it up in the help files to see what include file is required: "stdlib.h". It's always been included in the original code from the begining.

What has changed from version 10 to version 14 that this error is now occuring?

And how do I fix it?

[StevenCooper]

I have found a simple solution to the current problem and the problem of Version 10 not working in Windows 11.

I uninstalled version 14.5, and installed version 11. Years ago, I had downloaded the setup.exe for version 11 and never installed it (ditto for version 12); I was perfectly happy with version 10.

[TimoVJL]

Version 10 was latest version, that have __stod in stdlib.h and version 13 in crt.lib
So a your source code have a problem with it, not following standard C.
Some an old user libs might refer to it.

Hint, remove Pelles C reg settings while testing different versions.

Code Select Expand

REGEDIT4
[-HKEY_CURRENT_USER\Software\Pelle Orinius]

[Robert]

Hi Steven:

Did you clean the Project of the old .obj files before rebuilding ?

If the source of LotteryScratchOffs.obj has not been changed, the source for LotteryScratchOffs.obj will not be recompiled and the old .obj will be used.

[StevenCooper]

Hi Steven:

Did you clean the Project of the old .obj files before rebuilding ?

If the source of LotteryScratchOffs.obj has not been changed, the source for LotteryScratchOffs.obj will not be recompiled and the old .obj will be used.

I've always forced a complete rebuild by saving the main include file, even if I changed nothing in it; this causes the compiler to rebuild everything in the project that includes that include file.

[Vortex]

Hi Steven,

You should not have to recompile everything if some files are not modified.

[Pelle]

POLINK: error: Unresolved external symbol '__stod' - referenced from 'C:\Users\steco\Documents\Pelles C Projects\LotteryScratchOffs\output\LotteryScratchOffs.obj'.

__stod() was an internal helper function, no longer needed, and (obviously) never documented.

This symbol can't pop out of thin air, so the most likely reasons are:
1) you are somehow pulling in (old) #include files from the wrong directory
2) the file LotteryScratchOffs.obj is not (re)built properly, or the associated source file (LotteryScratchOffs.c ?!) contains some private reference to __stod.