Command line ifort fails to link static library-error LNK1120 unresolved external

[Patrick_G_]

Hi,

I have a static library UTILIB.LIB built in Visual Studio project UTILIB that includes recursive subroutine REPLACE_STRING. I have a project with main program EDITLINE.FOR that calls routine REPLACE_STRING in UTILIB. If I add UTILIB.LIB to the EDITLINE project I can successfully build my executable. However, if I try to compile EDITLINE.FOR and link from the command line within the Intel Development window (C:\Program Files (x86)\Intel\Composer XE 2013 SP1>) it always fails with the  LNK1120 unresolved external reference error for REPLACE_STRING. I have copied of both the main program EDITLINE.FOR and library UTILIB>LIB in the same folder. I have tried several things:

- adding complete path for my library(c:\fortran\UTILIB.LIB) to the LIB environment variable

- added the complete path to the ifort command: ifort c:\fortran\EDITLINE.FOR c:\fortran\UTILIB.LIB

- added a link option(getting desperate): ifort c:\fortran\EDITLINE.FOR /link c:\fortran\UTILIB.LIB

Any other suggestions? My PC configuration info is below. Thanks - Pat G.

DELL PC, Intel Core I5, 64-bit
Windows 7 Enterprise
Visual Studio 2010, 10.0.40219.1 SP1Rel

[Martyn_C_Intel]

Have you tried using Dumpbin /symbols on your object file and library, to see whether the symbols for REPLACE_STRING match?  If they are big files, use /OUT:filename  to write the output to a file, and then FIND to search it.

 Do you get unresolved references for functions that are not declared as recursive? If not, are you compiling both caller and callee with /recursive ?   (I haven't tested whether this matters, but it might). Also, if REPLACE_STRING is not part of a module that is USEd,  try creating an interface for REPLACE_STRING and placing it in the calling routine.

[Patrick_G_]

I have tried to isolate the problem by starting over and stripping things down to the most basic examples. I have a simple program in one file and it calls a simple subroutine in the other file. See below.

Main program file Pat_TestProg.for:
 program Pat_TestProg
c-----------------------------------------------------------
c simple test program to call a routine in a static library
c-----------------------------------------------------------
 real zval1, zval2
 zval1 = 1.4
 zval2 = .2
 call Pat_ShowSum(zval1, zval2)
 stop
 end

Subroutine file Pat_ShowSum:
 subroutine Pat_ShowSum(zarg1, zarg2)
 real zarg1, zarg2
 write(*,*)'Sum=', zarg1 + zarg2
 return
 end

I can compile, link and execute this code successfully using three methods.
1) Compile each file, and link with no library:
ifort /c Pat_TestProg.for Pat_ShowSum.for
ifort /exe:Pat_TestProg0 Pat_TestProg.obj Pat_ShowSum.obj

2) Compile subroutine and create static library from command line, then compile main program and link with library:
ifort /c Pat_ShowSum.for
lib /out:Pat_Lib2.lib Pat_ShowSum.obj
ifort /exe:Pat_TestProg2.exe Pat_TestProg.for Pat_Lib2.lib

3)  Create a Visual Studio Static Library project Pat_Lib1 that includes the identical subroutine Pat_ShowSum. Then create a Visual Studio Fortran Application project that includes main program Pat_TestProg and link to Pat_Lib1. I can then build a Pat_TestProg.exe that also executes successfully.

However, if I try to do this from the command line with compile and link it fails with the "fatal error LNK1120: 1 unresolved externals" error message because it cannot find my subroutine Pat_ShowSum:
4) Compile main program and link to library created in Visual Studio:
ifort /exe:Pat_TestProg1.exe Pat_TestProg.for Pat_Lib1.lib

I believe that Martyn has correctly suggested that the cause for failure is the lack of an INTERFACE for my subroutine. I must confess ignorance of how to use INTERFACE but I noticed that the Visual Studio Static Library project always creates a file called "pat_showsum__genmod.f90" that contains the INTERFACE code. As Martyn suggested I dumped each library and notice that the Pat_Lib1.lib which fails has symbol "_PAT_SHOWSUM" with a leading underscore but the Pat_Lib2.lib which works ok has symbol "PAT_SHOWSUM". See dumps below. At this point I do not know how to fix the problem other than using one of the less desirable but successful methods I described in 1) - 3) above ,and need to move on. Thanks - Pat G.

Failing library:
Dump of file Pat_Lib1.lib
File Type: LIBRARY

COFF SYMBOL TABLE

000 00000001 ABS    notype       Static       | @feat.00

001 00000000 SECT1  notype       Static       | .rdata

    Section length   64, #relocs    4, #linenums    0, checksum        0
003 00000000 SECT1  notype       Static       | __STRLITPACK_0
004 00000018 SECT1  notype       Static       | __rtc_frame_desc_2.2
005 00000000 SECT2  notype       Static       | .text
    Section length   C4, #relocs    8, #linenums    0, checksum        0
007 00000000 SECT2  notype ()    External     | _PAT_SHOWSUM
008 00000000 SECT3  notype       Static       | .debug$S
    Section length  424, #relocs    4, #linenums    0, checksum        0
00A 00000000 SECT6  notype       Static       | .debug$T
    Section length   84, #relocs    0, #linenums    0, checksum        0
00C 00000000 UNDEF  notype ()    External     | _for_write_seq_lis
00D 00000000 UNDEF  notype ()    External     | _for_write_seq_lis_xmit
00E 00000000 UNDEF  notype ()    External     | @_RTC_CheckStackVars@8
00F 00000000 UNDEF  notype ()    External     | __RTC_CheckEsp
010 00000008 SECT1  notype       Static       | __STRLITPACK_2
011 00000010 SECT1  notype       Static       | __STRLITPACK_3
012 00000044 SECT1  notype       Static       | __STRLITPACK_1
013 00000000 UNDEF  notype       External     | __fltused
014 00000000 SECT4  notype       Static       | .drectve
    Section length   BA, #relocs    0, #linenums    0, checksum        0
016 00000000 SECT5  notype       Static       | .trace
    Section length   A0, #relocs    2, #linenums    0, checksum        0

String Table Size = 0xBD bytes

  Summary

         424 .debug$S
          84 .debug$T
          BA .drectve
          64 .rdata
          C4 .text
          A0 .trace

Successful library:
Dump of file Pat_Lib2.lib
File Type: LIBRARY

COFF SYMBOL TABLE
000 00000000 SECT1  notype       Static       | .text
    Section length   90, #relocs    5, #linenums    0, checksum        0
002 00000000 SECT1  notype ()    External     | PAT_SHOWSUM
003 00000000 SECT2  notype       Static       | .rdata
    Section length   18, #relocs    0, #linenums    0, checksum        0
005 00000010 SECT2  notype       Static       | __STRLITPACK_0
006 00000000 UNDEF  notype ()    External     | for_write_seq_lis
007 00000000 UNDEF  notype ()    External     | for_write_seq_lis_xmit
008 00000000 SECT3  notype       Static       | .xdata
    Section length    C, #relocs    0, #linenums    0, checksum        0
00A 00000000 SECT4  notype       Static       | .pdata
    Section length    C, #relocs    3, #linenums    0, checksum        0
00C 00000000 SECT2  notype       Static       | __STRLITPACK_2.0.1
00D 00000008 SECT2  notype       Static       | __STRLITPACK_3.0.1
00E 00000000 UNDEF  notype ()    External     | __ImageBase
00F 00000000 UNDEF  notype       External     | _fltused
010 00000000 SECT5  notype       Static       | .drectve
    Section length   B9, #relocs    0, #linenums    0, checksum        0

String Table Size = 0x7A bytes

  Summary

          B9 .drectve
           C .pdata
          18 .rdata
          90 .text
           C .xdata

[mecej4 · Accepted solution]

I think that the .OBJ/.LIB file whose symbols include _PAT_SHOWSUM is a 64-bit version, and the one which has PAT_SHOWSUM is a 32-bit version. You cannot mix 32-bit objects/libraries with 64-bit objects/libraries. 

Look at your VS project settings and make sure that you have specified the same target architecture for all parts, i.e., all for ia32 or all for x64.

[Patrick_G_]

My two dumps above got mucked when posted. I tried to insert as snippet of plain-text to preserve fixed-width font but instead got proportional and all CR-LFs removed. If interested please see the attachments here.

[Patrick_G_]

Mecej4 pointed me in the right direction - the problem does seem to be a 32-bit vs. 64-bit mis-match. If I opened my command line window using "IA-32" instead of "Intel 64" my compile and link to Pat_Lib1 works. I believe the "underscore" symbols are for 32-bit though as opposed to 64-bit... and a big THANK YOU to Mecej4!