ld: library not found for -lcrt0.o

Question

ld: library not found for -lcrt0.o

Hi, I'm doing research at Memorial Sloan-Kettering Cancer Center, and I am trying to compile some c code with an intel compiler and a -static flag. I'm getting an error:
ld: library not found for -lcrt0.o
Does anyone know how to fix this?
Thanks, it's holding up my research!
Sean

iMac 24 inch, Mac OS X (10.5.5)

Posted on Mar 18, 2009 10:34 AM

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Answer 1

Top-ranking reply

RayNewbie

Level 5

6,810 points

Mar 18, 2009 3:01 PM in response to Sean McGuffee

crt0.o looks like the startup module, which is system dependent. In other words you are trying to port your program from one system to another, and the target system probably uses a different startup module.

Your first try is to remove -lcrt0.o from the build command line and let the system link to its default startup code. However be aware that porting code is not usually a job for a beginner, and the absence of crt0.o may be only the start of the problems you'll need to solve.

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Answer 2

ericmeyers

Level 4

1,410 points

Mar 18, 2009 4:52 PM in response to Sean McGuffee

Are you calling ld directly? If so, this is normal. Let the compiler call ld on it's own and it will bring in the startup code.

Under the hood when the compiler calls the linker for you it adds -lcrt1.10.5.o -lSystem

...

Oops, just read your post closer. I think you're screwed.

-static
On systems that support dynamic linking, this prevents linking with the shared libraries. On
other systems, this option has no effect.

This option will not work on Mac OS X unless all libraries (including libgcc.a) have also been
compiled with -static. Since neither a static version of libSystem.dylib nor crt0.o are
provided, this option is not useful to most people.

Eric

Message was edited by: ericmeyers

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Answer 3

ericmeyers

Level 4

1,410 points

Mar 20, 2009 3:28 PM in response to Sean McGuffee

Easy. In your Makefile just do something like this ...


UNAME := $(shell uname)
ifneq ($(UNAME),Darwin)
CFLAGS := $(CFLAGS) -static 
endif

Eric

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Answer 4

RayNewbie

Level 5

6,810 points

Mar 19, 2009 10:18 AM in response to Sean McGuffee

Yes, please try your build without -static. Are you working from the Terminal command line? Do you know why you need icc? What happens when you use gcc (or just cc) without any options?

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Answer 5

Mar 19, 2009 12:59 PM in response to RayNewbie

Well, my program takes 45 minutes to run on a small sample of data with gcc, but it only takes 15 minutes with icc. I can get it to work without -static. It seems completely irrational to me to do that, but I guess with the current state of a mac, that is what I'll have to do. I don't know why my program should have to go waste time reading directories of shared libraries, but I can't seem to do anything about it. Maybe in the end I'll have to install the gnu gcc myself with at -static option at that point, if I really want to waste time. For now, I'm just going to give up on mac supplying the static libraries for gcc. I guess it's far to much to ask for the most obviously important part of a computer to come automatically installed.

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Answer 6

ericmeyers

Level 4

1,410 points

Mar 19, 2009 3:31 PM in response to Sean McGuffee

What? So write your Makefile to query the platform it's on (like uname) and skip the -static flag. No need to edit it every time.

Eric

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Answer 7

ericmeyers

Level 4

1,410 points

Mar 24, 2009 3:03 PM in response to Sean McGuffee

That's not what I said. I was comparing static and dynamic libraries. You shouldn't be linking runtimes from gcc against code compiled with icc.

The fact icc produces more efficient code than gcc doesn't suprise me (and if it didn't icc would be a complete waste of money).

Why Intel doesn't provided both static and dynamic runtimes is beyond me.

I'm just telling you from experience 99.9% of folks don't link statically against language runtimes (even on Windows.)

Eric

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Answer 8

Mar 18, 2009 11:13 AM in response to orangekay

You are right, I don't understand how icc works completely in that it does seem to by calling a linker, ld, even though it's an icc command that starts the process.
You completely got the problem right though, there is no libcrt0.a file anywhere. The dynamic library that is used when I don't compile with -static is: -lcrt1.10.5.o, a different file altogether, and I can find it at:
/Developer/SDKs/MacOSX10.5.sdk/usr/lib/crt1.10.5.o for one location. I don't know for sure if that's the one it uses though. I got the "-lcrt1.10.5.o" info from putting a -v in the icc command line.

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Answer 9

orangekay

Level 5

4,085 points

Mar 18, 2009 10:46 AM in response to Sean McGuffee

That's from the linker, not the compiler. Where is the library it can't find?

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Answer 10

Mar 20, 2009 10:58 PM in response to Sean McGuffee

VMware Fusion ($60) with an Ubuntu virtual machine?

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Answer 11

Mar 19, 2009 1:04 PM in response to RayNewbie

I guess I should also mention another reason this is frustrating. I want to be able to use one version of my code via CVS. However, I absolutely have to use -static in my makefile on the linux clusters I use. Thus, it's annoying to have to modify the makefile every time I update the program on the mac by taking the -static line out. Furthermore, it's annoying that my free copy of icc on linux is more capable than my expensive copy of icc on mac because of a silly preference someone at mac seems to have.

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Answer 12

orangekay

Level 5

4,085 points

Mar 19, 2009 1:39 PM in response to Sean McGuffee

I'm not so sure you know what a shared library is or how one works, but I would suggest actually profiling your code before blaming all those tremendously expensive method resolutions that generally only happen once in the process' lifetime for your code's slowness. What's far too much is to ask for the most basic aspects of software development to come automatically installed in every end user's head.

Porting software from one operating system to another is generally not something a complete beginner should attempt unless they happen to enjoy the sort of frustration you're currently experiencing. If a tool you need to do your job only runs in Linux, then using Linux should be a no-brainer.

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Answer 13

RayNewbie

Level 5

6,810 points

Mar 19, 2009 2:33 PM in response to Sean McGuffee

For someone doing potentially life saving cancer research, I can't help observing you seem very focused on what annoys you. Maybe we'll all live longer if you consider an attitude adjustment. If you don't like your Mac, give it to a loving home and get on with your important work, ok?

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Answer 14

Mar 20, 2009 7:34 AM in response to ericmeyers

This is a good idea--I think I should do this. I think there is a variable named $MACHTYPE that I could use. Do you know a another way or ways to probe the architecture of a machine from a command line and/or makefile?

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Answer 15

Mar 20, 2009 7:35 AM in response to ericmeyers

This seems odd to me. I thought the reason people originally developed dynamic linking was because of hardware limitations, i.e. to save space on disks and memory etc... Now that machines have literally gibabytes of memory, why would anyone want to compile in anyway other than static?

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