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D.gnu - Strange linker problems

reply Benjamin Thaut <code benjamin-thaut.de> writes:
I have a strange problem with gdc. The linker reports undefined 
references to symbols, but exactly those symbols exist in the library 
that I'm linking into the executable. The error message I get is:

C:\Users\Benjamin\AppData\Local\Temp\cc4pUOfp.o:main.d:(.text+0x3a): 
undefined reference to `_D6thBase2io8writeflnFAyaYm'

But:

nm libthBase64d_mingw.a | grep writefln
000000000003c9b2 T _D6thBase2io8writeflnFAyaYm

I'm building with:

gdc -m64 
-I"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..
..\druntime\import" 
-I"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos" 
-I"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\thBase\src" 
-fversion=NOGCSAFE -o "test.exe" 
-L"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos" 
-L. -lthBase64d_mingw -debuglib=phobosnogc64d_mingw -Wl,--verbose=2 
-defaultlib=phobosnogc64d_mingw -v -pipe -nostdinc main.d

The verbose output of the linker also shows that it finds the correct 
library file:

attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/libt
Base64d_mingw.dll.a 
failed
attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/t
Base64d_mingw.dll.a 
failed
attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/
ibthBase64d_mingw.a 
failed
attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos
thBase64d_mingw.lib 
failed
attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/li
thBase64d_mingw.dll 
failed
attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos
thBase64d_mingw.dll 
failed
attempt to open 
C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos\
ibthBase64d_mingw.a 
failed
attempt to open ./libthBase64d_mingw.dll.a failed
attempt to open ./thBase64d_mingw.dll.a failed
attempt to open ./libthBase64d_mingw.a succeeded

Any ideas what is going wrong here?

Kind Regards
Benjamin Thaut
Mar 18 2013
parent reply Johannes Pfau <nospam example.com> writes:
Am Mon, 18 Mar 2013 08:07:43 +0100
schrieb Benjamin Thaut <code benjamin-thaut.de>:


 I have a strange problem with gdc. The linker reports undefined 
 references to symbols, but exactly those symbols exist in the library 
 that I'm linking into the executable. The error message I get is:
 
 C:\Users\Benjamin\AppData\Local\Temp\cc4pUOfp.o:main.d:(.text+0x3a): 
 undefined reference to `_D6thBase2io8writeflnFAyaYm'
 
 But:
 
 nm libthBase64d_mingw.a | grep writefln
 000000000003c9b2 T _D6thBase2io8writeflnFAyaYm
 
 I'm building with:
 
 gdc -m64 
 -I"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..
..\druntime\import" 
 -I"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos" 
 -I"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\ga
e\..\..\thBase\src" 
 -fversion=NOGCSAFE -o "test.exe" 
 -L"C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos" 
 -L. -lthBase64d_mingw -debuglib=phobosnogc64d_mingw -Wl,--verbose=2 
 -defaultlib=phobosnogc64d_mingw -v -pipe -nostdinc main.d
 
 The verbose output of the linker also shows that it finds the correct 
 library file:
 
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/libt
Base64d_mingw.dll.a 
 failed
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/t
Base64d_mingw.dll.a 
 failed
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/
ibthBase64d_mingw.a 
 failed
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos
thBase64d_mingw.lib 
 failed
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos/li
thBase64d_mingw.dll 
 failed
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos
thBase64d_mingw.dll 
 failed
 attempt to open 
 C:\Users\Benjamin\Documents\d-projects\Spacecraft-git\game\..\..\phobos\
ibthBase64d_mingw.a 
 failed
 attempt to open ./libthBase64d_mingw.dll.a failed
 attempt to open ./thBase64d_mingw.dll.a failed
 attempt to open ./libthBase64d_mingw.a succeeded
 
 Any ideas what is going wrong here?
 
 Kind Regards
 Benjamin Thaut


Could it be this:
http://stackoverflow.com/questions/8640642/gcc-link-order-changed

Something changed in ld some time ago and the order in which libraries
are passed to ld is now important. The library which defines
_D6thBase2io8writeflnFAyaYm must be passed to ld first, the lib/object
file using it second.
Mar 18 2013
parent Benjamin Thaut <code benjamin-thaut.de> writes:
Am 18.03.2013 09:51, schrieb Johannes Pfau:

 Could it be this:
 http://stackoverflow.com/questions/8640642/gcc-link-order-changed

 Something changed in ld some time ago and the order in which libraries
 are passed to ld is now important. The library which defines
 _D6thBase2io8writeflnFAyaYm must be passed to ld first, the lib/object
 file using it second.


So this is a bug in gdc? Shouldn't gdc always pass the object files to 
the linker first? I noticed that if I change the build command to

gdc -m64 -g -fno-inline-functions -fdebug 
-I"C:\Users\Benjamin\Documents\d-projects\thBase\src\..\..\druntime\import" 
-I"C:\Users\Benjamin\Documents\d-projects\thBase\src\..\..\phobos" 
-fversion=NOGCSAFE -fversion=MEMORY_TRACKING -fdeps="Debug Lib 
GDC\thBase.dep" -nostdinc -O0 -c -o "Debug Lib GDC\thBase.obj"  "Debug 
Lib GDC\thBase.build.rsp"

It works correctly.

Thanks for the tip.

Kind Regards
Benjamin Thaut
Mar 18 2013