Hello all,
Does anyone have any inside why I can't get the below simple C API test to
link? This is on a 32-bit Gentoo Linux system and LLVM TOT which was
compiled with enable-optimized, gcc is 4.3.2.
15:26|melis at juggle2:~/c/llvmpy> cat t.c
#include "llvm-c/Core.h"
int main()
{
LLVMContextRef ctx;
ctx = LLVMContextCreate();
return 0;
}
15:29|melis at juggle2:~/c/llvmpy> llvm-config --cflags --ldflags --libs all
-I/home/melis/llvm/include -D_DEBUG -D_GNU_SOURCE -D__STDC_LIMIT_MACROS
-D__STDC_CONSTANT_MACROS -O3 -fomit-frame-pointer -fPIC
-L/home/melis/llvm/lib -lpthread -ldl -lm
-lLLVMLinker -lLLVMipo -lLLVMInterpreter -lLLVMInstrumentation -lLLVMJIT
-lLLVMExecutionEngine -lLLVMDebugger -lLLVMCBackend -lLLVMCBackendInfo
-lLLVMBitWriter -lLLVMX86AsmParser -lLLVMX86AsmPrinter -lLLVMX86CodeGen
-lLLVMSelectionDAG -lLLVMX86Info -lLLVMAsmPrinter -lLLVMCodeGen
-lLLVMScalarOpts -lLLVMTransformUtils -lLLVMipa -lLLVMAsmParser
-lLLVMArchive -lLLVMBitReader -lLLVMAnalysis -lLLVMTarget -lLLVMMC
-lLLVMCore -lLLVMSupport -lLLVMSystem
15:29|melis at juggle2:~/c/llvmpy> gcc -W -Wall -o blah `llvm-config --cflags
--ldflags --libs all` t.c
/tmp/ccs4MbKp.o: In function `main':
t.c:(.text+0x21): undefined reference to `LLVMContextCreate'
collect2: ld returned 1 exit status
15:29|melis at juggle2:~/c/llvmpy> nm ~/llvm/lib/libLLVMCore.a | grep
LLVMContextCreate
00001bc0 T LLVMContextCreate
Regards,
Paul
"Paul Melis" <llvm at assumetheposition.nl> writes:> 15:29|melis at juggle2:~/c/llvmpy> gcc -W -Wall -o blah `llvm-config --cflags > --ldflags --libs all` t.c > /tmp/ccs4MbKp.o: In function `main': > t.c:(.text+0x21): undefined reference to `LLVMContextCreate' > collect2: ld returned 1 exit status > > 15:29|melis at juggle2:~/c/llvmpy> nm ~/llvm/lib/libLLVMCore.a | grep > LLVMContextCreate > 00001bc0 T LLVMContextCreateTry this: gcc t.c -W -Wall -o blah `llvm-config --cflags --libs all --ldflags` -- Óscar
Óscar Fuentes wrote:> "Paul Melis" <llvm at assumetheposition.nl> writes: > >> 15:29|melis at juggle2:~/c/llvmpy> gcc -W -Wall -o blah `llvm-config >> --cflags >> --ldflags --libs all` t.c >> /tmp/ccs4MbKp.o: In function `main': >> t.c:(.text+0x21): undefined reference to `LLVMContextCreate' >> collect2: ld returned 1 exit status >> >> 15:29|melis at juggle2:~/c/llvmpy> nm ~/llvm/lib/libLLVMCore.a | grep >> LLVMContextCreate >> 00001bc0 T LLVMContextCreate > > Try this: > > gcc t.c -W -Wall -o blah `llvm-config --cflags --libs all --ldflags`Thanks! Moving t.c to the front of the command-line fixes it (although --ldflags still needs to go before --libs in the above line). And I need to link with g++ instead of gcc. I guess I didn't figure this one out because when you normally manually specify libraries they always go *after* the source file argument. Splitting the llvm-config call into a cxxflags and a --libs/--ldflags part and putting the sources in between is probably cleaner in this respect. Paul
"Paul Melis" <llvm at assumetheposition.nl> writes:>>> 15:29|melis at juggle2:~/c/llvmpy> gcc -W -Wall -o blah `llvm-config >>> --cflags >>> --ldflags --libs all` t.c >>> /tmp/ccs4MbKp.o: In function `main': >>> t.c:(.text+0x21): undefined reference to `LLVMContextCreate' >>> collect2: ld returned 1 exit status >>> >>> 15:29|melis at juggle2:~/c/llvmpy> nm ~/llvm/lib/libLLVMCore.a | grep >>> LLVMContextCreate >>> 00001bc0 T LLVMContextCreate >> >> Try this: >> >> gcc t.c -W -Wall -o blah `llvm-config --cflags --libs all --ldflags` > > Are you sure that's what you meant? Now the linker can't find anything > anymore and I get tons of unresolved symbols.That is because -L comes after the LLVM libraries. Try gcc t.c -W -Wall -o blah `llvm-config --cflags --ldflags --libs all` However, if your linker is sensitive to library order, you may get unresolved externals for -lpthread and other system libraries that are list before the LLVM libraries on the llvm-config output. If that happens try gcc t.c -W -Wall -o blah -L/home/melis/llvm/lib `llvm-config --cflags --libs all --ldflags` HTH. -- Óscar