Thread: Undefined reference

I am using Cygwin and trying to compile a program with gcc, but get these "undefined reference" errors for many functions. They all seem to be stdio.h functions, but I am not getting an error saying stdio.h is not found, so maybe its something within that is corrupt? Any help is appreciated!

Code:

XXXXXX.o: In function `XXXXXX':
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:470: undefined reference to `fgets'
XXXXXX.o: In function `main':
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:161: undefined reference to `fseek'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:174: undefined reference to `strtod'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:161: undefined reference to `fseek'
XXXXXX.o: In function `XXXXXX':
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:577: undefined reference to `memcpy'
XXXXXX.o: In function `XXXXXX':
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:397: undefined reference to `sscanf'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:400: undefined reference to `__ctype_ptr'
XXXXXX.o: In function `XXXXXX':
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:491: undefined reference to `__ctype_ptr'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:494: undefined reference to `__ctype_ptr'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:513: undefined reference to `__ctype_ptr'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:514: undefined reference to `sscanf'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:519: undefined reference to `__ctype_ptr'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:541: undefined reference to `__ctype_ptr'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:532: undefined reference to `sscanf'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:504: undefined reference to `sscanf'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:513: undefined reference to `__ctype_ptr'
/cygdrive/c/XXXXXX/XXXXXX/GNU/XXXXXX_GNU/XXXXXX/build/../XXXXXX.c:537: undefined reference to `memcpy'

Do you have glibc somewhere? Somewhere where gcc can find it?

I'm using Cygwin, so it has newlib instead of glibc. I can compile other programs but can't seem to figure out why I am getting these errors. Thanks for your input!

So if you can compile other things but not this, does the makefile that you are using (I'm making a big assumption here) set paths assuming glibc? (I'm seeing a lot of GNU in the error messages.) Now __ctype_ptr is (or should be, since it starts with __) implementation-specific, and I don't know whether newlib uses it or not.

I don't think my makefile is assuming that I'm using glibc, it was a template from another program that ran with Cygwin. Should I add a LIBS command or something to declare where to look for stdio.h? Here is my makefile:

Code:

bin_PROGRAMS = File1 \
		   File1.chksum.elf \
		   File1.y16 

SOURCE_DIR = $(top_srcdir)
SOURCE_SRC_DIR = $(SOURCE_DIR)
SOURCE_INCLUDE_DIR = /../include
SOURCE_COMMON_DIR = $(SOURCE_DIR)/../common
SOURCE_LDSCRIPT_DIR = $(SOURCE_DIR)
SOURCE_PROM_DIR = $(SOURCE_DIR)
SOURCE_DOC_DIR = $(SOURCE_DIR)/doc
SOURCE_DOC_NOTES_DIR = $(SOURCE_DOC_DIR)/notes
SOURCE_DOC_EXAMPLES_DIR = $(SOURCE_DOC_DIR)/examples

BUILD_DIR = $(top_builddir)
BUILD_SRC_DIR = $(BUILD_DIR)

##Line 23

BUILD_PROM_DIR = $(BUILD_DIR)
BUILD_DOC_DIR = $(BUILD_DIR)/doc


#List of files that are sources to File1.exe
File1_SOURCES = File1Main.c \
                File2.c \
                File3.c \
                File4.c \
                File5.c \
                File6.c \
                File7.c \
                $(SOURCE_COMMON_DIR)/File8.c \
                $(SOURCE_COMMON_DIR)/File8Calls.s \
                $(SOURCE_COMMON_DIR)/Cksum.s \
                $(SOURCE_COMMON_DIR)/bits.s 

AM_CFLAGS=-O3 -Wno-main -fomit-frame-pointer -I$(SOURCE_INCLUDE_DIR) \
          -m68000 $(DEBUG) \
          -Wa,-alh="$(BUILD_PROM_DIR)/`echo "$@" | sed -e "s/\.$(OBJEXT)/\.lst/g"`",-L
AM_CCASFLAGS=$(AM_CFLAGS)


#Linker Flags
AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L`m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"`
File1_LINK=m68k-elf-ld $(AM_LDFLAGS) -o $@ 
File1_LDADD=-lgcc

M68K_SREC_CHKSUM = @M68K_SREC_CHKSUM@




.PHONY: File1.y16 File1.chksum.elf
SUFFIXES = .y16 .elf

File1.chksum.elf: File1
	@ m68k-elf-objcopy \
		--srec-len=14 \
		-I elf32-m68k \
		-O srec \
		--set-start 0x0000 \
		--change-section-address GPARMS=0x0000 \
		--change-section-address APPLINIT=0x000c \
		--change-section-address APPPROG=0x0100 \
		--change-section-address .text=0x0100 \
		--no-change-warnings \
		--remove-section=APPDATA \
		--remove-section=.bss \
		--remove-section=COMMON \
		$< \
		$<.srec
	@ echo -n "File1.y16 : " > File1-checksums.txt
	@ $(M68K_SREC_CHKSUM) -T word-2s-comp-big -I $<.srec -A 0xFFFE -V 0xFFFF >> File1-checksums.txt
	@ echo "" >> File1-checksums.txt
	@ echo "unsigned short __attribute__ ((section (\".checksum\"))) checksum=`$(M68K_SREC_CHKSUM) -T word-2s-comp-big -I $<.srec -R -A 0xFFFE -V 0xFFFF`;" > gm-checksum.c
	@ echo "Building Application with Checksum"
	@ $(CC) $(CFLAGS) -c File1-checksum.c -o File1-checksum.o
	@ $(File1_LINK) $(File1_OBJECTS) File1-checksum.o $(File1_LDADD)

File1.y16: File1.chksum.elf
	@ m68k-elf-objcopy \
		--srec-len=14 \
		--set-start 0x0000 \
		--change-section-address GPARMS=0x0000 \
		--change-section-address APPLINIT=0x000c \
		--change-section-address APPPROG=0x0100 \
		--change-section-address .text=0x0100 \
		--change-section-address .checksum=0xFFFE \
		--no-change-warnings \
		--remove-section=APPDATA \
		--remove-section=.bss \
		--remove-section=COMMON \
		-I elf32-m68k \
		-O srec \
		$< \
		$@
	@ m68k-elf-objcopy \
		--srec-len=14 \
		--set-start 0x0000 \
		--change-section-address GPARMS=0x10000 \
		--change-section-address APPLINIT=0x1000c \
		--change-section-address APPPROG=0x10100 \
		--change-section-address .text=0x10100 \
		--change-section-address .checksum=0x1FFFE \
		--no-change-warnings \
		--remove-section=APPDATA \
		--remove-section=.bss \
		--remove-section=COMMON \
		-I elf32-m68k \
		-O srec \
		$< \
		./tests/test.h68

Originally Posted by bithub

It already knows where stdio.h is -- that's not the error you are getting. The problem is you are not linking to an implementation of the standard C library. I don't know much about cygwin, but I would first make sure you can compile and run a simple "Hello World" program.

Yes that's true. I have run other programs successfully which is why I suspect my makefile has errors

I see -m68000 there in your flags. Are you trying to use this as a cross-compiler and create an executable for a 68K processor?

Originally Posted by tabstop

I see -m68000 there in your flags. Are you trying to use this as a cross-compiler and create an executable for a 68K processor?

Yes, sorry I didn't explain that earlier. I have another program that I have done the same thing for and it worked, so I used those files as templates and added on. I don't get these errors when compiling the other program

Update: I changed the line

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L`m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"

to

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib-m68000 --print-libgcc | sed -e "s/libgcc.a//g"

And I no longer get the reference errors...just other ones.

Originally Posted by TheEngineer

Update: I changed the line

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L`m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"

to

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib-m68000 --print-libgcc | sed -e "s/libgcc.a//g"

And I no longer get the reference errors...just other ones.

Really? Why? Are you sure that's what you did? I can't imagine --print-libgcc | sed -e "s/libgcc.a//g" being a very good compiler flag.

So one day someone should show you what ` means. Maybe today's that day:

When bash sees `, it runs that command somewhere, and substitutes the result back in the command to be run. So this:

Code:

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L`m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"`

causes the command in the backticks, namely

Code:

m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"

to be run, the result of which is pasted back in the AM_LDFLAGS variable after the -L. (Presumably m68k-elf-gcc etc causes the absolute paths of gcclib.a to be printed, because sed is looking for that filename and strips it off, leaving just the path.) This means that gcc never sees --print-libgcc, or |, or sed, which is good, because otherwise it would then try to pipe the result of gcc into sed and heaven only knows what's going to happen then.

Originally Posted by tabstop

So one day someone should show you what ` means. Maybe today's that day:

When bash sees `, it runs that command somewhere, and substitutes the result back in the command to be run. So this:

Code:

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L`m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"`

causes the command in the backticks, namely

Code:

m68k-elf-gcc -m68000 --print-libgcc | sed -e "s/libgcc.a//g"

to be run, the result of which is pasted back in the AM_LDFLAGS variable after the -L. (Presumably m68k-elf-gcc etc causes the absolute paths of gcclib.a to be printed, because sed is looking for that filename and strips it off, leaving just the path.) This means that gcc never sees --print-libgcc, or |, or sed, which is good, because otherwise it would then try to pipe the result of gcc into sed and heaven only knows what's going to happen then.

Please excuse my ignorance (I did not write these files). I understand now the operation you described. I changed the line to:

Code:

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib -m68000

When i recompiled, I got the error:

"m68k-elf-ld: cannot find -lgcc"

Removing the -lgcc command gives reference errors again

Originally Posted by TheEngineer

Please excuse my ignorance (I did not write these files). I understand now the operation you described. I changed the line to:

Code:

AM_LDFLAGS=-M -cref -File1 File1.File1 -T $(SOURCE_LDSCRIPT_DIR)/File1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib -m68000

When i recompiled, I got the error:

"m68k-elf-ld: cannot find -lgcc"

Removing the -lgcc command gives reference errors again

So, do you have libgcc.a at ../../../../cygwin/opt/m68k/m68k-elf/lib? And that's a lot of up directories -- maybe try an absolute path instead.