Undefined reference?

**Brandon77** · 08-11-2009

I am using Cygwin and trying to cross 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!

Errors:

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'

Possibly it's an error in my makefile??

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

**Rubberman** · 08-11-2009

You are cross-compiling for a 68k chip? These unresolved references should be in libc, which it seems you are missing for the target platform. Also, you probably want to statically link your 68k system libraries.

**Brandon77** · 08-11-2009

Originally Posted by Rubberman

You are cross-compiling for a 68k chip? These unresolved references should be in libc, which it seems you are missing for the target platform. Also, you probably want to statically link your 68k system libraries.

Yes, I am cross compiling for a 68k. I looked up the references and they are all in stdio.h - newlib (what Cygwin uses instead of glibc). The makefile here was copied from another program that does the same thing for a smaller program, all I did was add to it, so I don't understand why I am getting all these errors.

What do you mean by statically linking my 68k system libraries?

Thanks

**Rubberman** · 08-11-2009

Originally Posted by Brandon77

Yes, I am cross compiling for a 68k. I looked up the references and they are all in stdio.h - newlib (what Cygwin uses instead of glibc). The makefile here was copied from another program that does the same thing for a smaller program, all I did was add to it, so I don't understand why I am getting all these errors.

What do you mean by statically linking my 68k system libraries?

Thanks

SInce you are building 68k executables, you need to link 68k libraries to the executable. Statically linking them means you don't need shared libraries to run the executables (bigger size, less versionitis issues). Your linker specifies a directory for the mc68k libraries, but you don't tell it which libraries to link (-lc -lm etc).

**Brandon77** · 08-11-2009

Originally Posted by Rubberman

SInce you are building 68k executables, you need to link 68k libraries to the executable. Statically linking them means you don't need shared libraries to run the executables (bigger size, less versionitis issues). Your linker specifies a directory for the mc68k libraries, but you don't tell it which libraries to link (-lc -lm etc).

Please excuse my ignorance (I did not write these files), but aren't the following lines linking the libraries?:

Code:

#Linker Flags
AM_LDFLAGS=-M -cref -File1 File1.map -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

**Brandon77** · 08-11-2009

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.

**Rubberman** · 08-11-2009

Originally Posted by Brandon77

Please excuse my ignorance (I did not write these files), but aren't the following lines linking the libraries?:

Code:

#Linker Flags
AM_LDFLAGS=-M -cref -File1 File1.map -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

It depends on what the command

Code:

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

returns. The -L (capital ell) tells the compiler where to find libraries, not which ones to link. So, it is only linking libgcc which apparently doesn't include other library stuff, assuming it is there. Without looking at your cygwin system configuration and mc68k libraries, etc. I cannot tell you more than this. Simply put, you are missing references, so either you aren't linking the required libraries, or if the referenced symbols are in libgcc.a then you might need to link it twice in order to resolve recursive references. When linking an executable with static libraries (libgcc.a), the linker only makes one pass thru the library. If parts in the library require other parts in the same library that have already been scanned but not linked, or if some other component is linked after the library but requires parts in the library not already linked, then you need to add another -lgcc to the link arguments.

**Rubberman** · 08-11-2009

Originally Posted by Brandon77

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.

Ok. What are the other errors you get? All you posted originally were the missing reference errors.

**Brandon77** · 08-11-2009

Originally Posted by Rubberman

Ok. What are the other errors you get? All you posted originally were the missing reference errors.

This is my current output:

Code:

make  all-am
make[1]: Entering directory `/cygdrive/c/XXXXX/XXXX/build'
m68k-elf-ld -M -cref -File1 file1.map -T ../file1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib -m68000 --print-libgcc | sed -e "s/libgcc.a//g"` -o File1  File1Main.o File2.o File3.o File4.o File5.o File6.o File7.o File8.o File9.o File10.o File11.o File12.o File13.o -lgcc 
/bin/sh: -c: line 0: unexpected EOF while looking for matching ``'
/bin/sh: -c: line 1: syntax error: unexpected end of file
make[1]: *** [File1] Error 2
make[1]: Leaving directory `/cygdrive/c/XXXX/XXXX/build'
make: *** [all] Error 2

**Rubberman** · 08-11-2009

Originally Posted by Brandon77

This is my current output:

Code:

make  all-am
make[1]: Entering directory `/cygdrive/c/XXXXX/XXXX/build'
m68k-elf-ld -M -cref -File1 file1.map -T ../file1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib -m68000 --print-libgcc | sed -e "s/libgcc.a//g"` -o File1  File1Main.o File2.o File3.o File4.o File5.o File6.o File7.o File8.o File9.o File10.o File11.o File12.o File13.o -lgcc 
/bin/sh: -c: line 0: unexpected EOF while looking for matching ``'
/bin/sh: -c: line 1: syntax error: unexpected end of file
make[1]: *** [File1] Error 2
make[1]: Leaving directory `/cygdrive/c/XXXX/XXXX/build'
make: *** [all] Error 2

Actually, you probably should remove the section where you pipe the output of --print-gcc to sed. Ie,

Code:

m68k-elf-ld -M -cref -File1 file1.map -T ../file1.ld -L../../../../cygwin/opt/m68k/m68k-elf/lib -m68000 -o File1  File1Main.o File2.o File3.o File4.o File5.o File6.o File7.o File8.o File9.o File10.o File11.o File12.o File13.o -lgcc

I suspect you will continue to get the unresolved references. Look in the m68k-elf/lib directory and see what is there. If you see libc.a, try adding -lc after the -lgcc.

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