Undefined references when building with LDFLAGS="-Wl,--no-undefined"

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When promoting shared libraries with LDFLAGS="-Wl,--no-undefined", tesseract 
3.0 produces a lot of undefined references when linking libs. As all the 
requirements should be linked with Makefile for shared libraries, following 
steps should fix the problem:

1. move ccstruct/callcpp.cpp into cutil/ subdir, which is the correct location 
of this source file, stand with its callcpp.h header.

2. modify following variables in Makefile:
 libtesseract_main_la_LIBADD = ../wordrec/libtesseract_wordrec.la ../image/libtesseract_image.la ../classify/libtesseract_classify.la ../ccstruct/libtesseract_ccstruct.la ../cutil/libtesseract_cutil.la ../viewer/libtesseract_viewer.la ../dict/libtesseract_dict.la ../ccutil/libtesseract_ccutil.la
 libtesseract_ccstruct_la_LIBADD = ../ccutil/libtesseract_ccutil.la ../viewer/libtesseract_viewer.la ../cutil/libtesseract_cutil.la ../image/libtesseract_image.la
 libtesseract_classify_la_LIBADD = ../ccutil/libtesseract_ccutil.la ../viewer/libtesseract_viewer.la ../cutil/libtesseract_cutil.la ../ccstruct/libtesseract_ccstruct.la ../dict/libtesseract_dict.la
 libtesseract_cutil_la_LIBADD = ../ccutil/libtesseract_ccutil.la ../viewer/libtesseract_viewer.la
 libtesseract_dict_la_LIBADD = ../ccutil/libtesseract_ccutil.la ../ccstruct/libtesseract_ccstruct.la ../cutil/libtesseract_cutil.la
 libtesseract_image_la_LIBADD = ../cutil/libtesseract_cutil.la ../ccutil/libtesseract_ccutil.la
 libtesseract_textord_la_LIBADD =../image/libtesseract_image.la ../classify/libtesseract_classify.la ../ccstruct/libtesseract_ccstruct.la ../cutil/libtesseract_cutil.la ../viewer/libtesseract_viewer.la ../dict/libtesseract_dict.la ../ccutil/libtesseract_ccutil.la
 libtesseract_training_la_LIBADD = ../image/libtesseract_image.la ../classify/libtesseract_classify.la ../ccstruct/libtesseract_ccstruct.la ../cutil/libtesseract_cutil.la ../viewer/libtesseract_viewer.la ../dict/libtesseract_dict.la ../ccutil/libtesseract_ccutil.la
 libtesseract_wordrec_la_LIBADD = ../ccutil/libtesseract_ccutil.la ../cutil/libtesseract_cutil.la ../classify/libtesseract_classify.la ../dict/libtesseract_dict.la ../image/libtesseract_image.la ../ccstruct/libtesseract_ccstruct.la ../viewer/libtesseract_viewer.la

Even after applying above modification, there are still problems:
1. when linking training:
training/commontraining.cpp:142: undefined reference to `Config'
That is because you set Config as application level variable (for cntraining), 
but call it in a shared lib. Maybe you should move corresponding function 
ParseArguments into cntraining also.

2. when linking textord:
/tmp/tesseract/BUILD/tesseract-3.00/textord/makerow.cpp:2850: undefined 
reference to `tesseract::Tesseract::compare_blobs(PBLOB*, ROW*, PBLOB*, ROW*)'
/tmp/tesseract/BUILD/tesseract-3.00/textord/makerow.cpp:2853: undefined 
reference to `tesseract::Tesseract::compare_blobs(PBLOB*, ROW*, PBLOB*, ROW*)'
.libs/tordmain.o: In function `find_components(BLOCK_LIST*, TO_BLOCK_LIST*, 
TO_BLOCK_LIST*, TBOX*)':
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:1013: undefined 
reference to `page_image'
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:142: undefined 
reference to `global_monitor'
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:166: undefined 
reference to `global_monitor'
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:172: undefined 
reference to `global_monitor'
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:179: undefined 
reference to `global_monitor'
.libs/tordmain.o: In function `textord_page(ICOORD, BLOCK_LIST*, 
TO_BLOCK_LIST*, TO_BLOCK_LIST*, tesseract::Tesseract*)':
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:554: undefined 
reference to `global_monitor'
/tmp/tesseract/BUILD/tesseract-3.00/textord/tordmain.cpp:1013: undefined 
reference to `interactive_mode'
.libs/wordseg.o: In function `make_words(ICOORD, float, BLOCK_LIST*, 
TO_BLOCK_LIST*, TO_BLOCK_LIST*, tesseract::Tesseract*)':
/tmp/tesseract/BUILD/tesseract-3.00/textord/wordseg.cpp:117: undefined 
reference to `global_monitor'

But those references are defined in ccmain. Which means, ccmain and textord are 
cross-referencing each other, which is not a good habit for shared libs.

Original issue reported on code.google.com by fundawang@gmail.com on 12 Dec 2010 at 12:10

[GoogleCodeExporter]

ccstruct/callcpp.cpp moved to cutil/callcpp.cpp in r603

Original comment by zde...@gmail.com on 15 Aug 2011 at 8:12

[GoogleCodeExporter]

Fixed in 3.01

Original comment by theraysm...@gmail.com on 18 Aug 2011 at 12:25

• Changed state: Fixed