The support will require more work, and postpone for now.

g++ builds require extra flags rejected by clang++. The bug is that the
flags are actually added unconditionally. This commit fixes the
condition.

See https://github.com/tesseract-ocr/tesseract/pull/1474

Not only version names like 4.0.0, but also version names like
v4.0.0 or tesseract-4.0.0 are now supported and give the same
GENERIC_MAJOR_VERSION = 4.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

The newer macros that replace the obsolete ones are already present in configure.ac.

  * AC_PROG_LIBTOOL -> LT_INIT
  * AC_LANG_CPLUSPLUS -> AC_LANG([C++])

This is the autoconf version shipped in RHEL/CentOS 6.

Tesseract's training tool text2image uses these two functions: 
pango_glyph_item_iter_init_start
pango_glyph_item_iter_next_cluster

That means it requires Pango >=1.22.0:
https://developer.gnome.org/pango/stable/api-index-1-22.html
https://developer.gnome.org/pango/stable/pango-Glyph-Storage.html#pango-glyph-item-iter-init-start
https://developer.gnome.org/pango/stable/pango-Glyph-Storage.html#pango-glyph-item-iter-next-cluster

It is only used by the compiler.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

Building with G++ on Darwin breaks when either AVX, AVX2, or SSE4.1
compiler option is set, unless G++ is actually CLANG.

This commit allows to build with G++, by asking G++ to delegate assembly
to the clang integrated assembler, instead of the GNU one.

Commit f9157fd9 changed the rules for
the documentation, so make always tried to build it and failed if
asciidoc was missing since that commit.

Now configure tests whether asciidoc is available and builds the
documentation conditionally. It also reports that to the user.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

That macro disables automated updates when configure.ac or a Makefile.am
changes. Normally those updates are wanted because users typically
forget running ./autogen.sh.

See also the GNU documentation why AM_MAINTAINER_MODE should not be used:
https://www.gnu.org/software/automake/manual/html_node/maintainer_002dmode.htmlSigned-off-by: NStefan Weil <sw@weilnetz.de>

Signed-off-by: NStefan Weil <sw@weilnetz.de>

AX_SPLIT_VERSION only works after AM_INIT_AUTOMAKE, so that macro had
to be moved.

GENERIC_MAJOR_VERSION, GENERIC_MINOR_VERSION and GENERIC_MICRO_VERSION
are now set automatically and can be used in further processing.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

Signed-off-by: NStefan Weil <sw@weilnetz.de>

While "echo -n" works on Debian GNU Linux, it fails to produce a valid
configure file on macOS, so try a different shorter solution.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

Use git to create the version string if possible.
Otherwise get the version from the VERSION file.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

Signed-off-by: NStefan Weil <sw@weilnetz.de>

Fix also a grammar issue.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

Libtool's convenience libraries should never be installed. Fixes #985.

* Fix grammar.
* Fix text ("after building ..." is not necessary).
Signed-off-by: NStefan Weil <sw@weilnetz.de>

libtiff is no longer needed for OpenCL, so remove that dependency.

It is still suggested for Windows to redirect warning messages
from the tesseract executable to the console.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

The OpenCL code of Tesseract uses TIFF functions, but the TIFF library
was not added to the linker flags for macOS.

This fixes builds with OpenCL on Mac.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

_mm256_extract_epi64 is not available for 32 bit platforms,
but it can be replaced by "a very simple workaround".
Signed-off-by: NStefan Weil <sw@weilnetz.de>

The current implementation for AVX uses 64 bit code,
so run the AVX test only when the compiler is a 64 bit compiler.

This fixes the broken implementation for 32 bit hosts
which provide AVX but call the stub of DotProductAVX.

Simplify also the conditional code for AVX_OPT and SSE41_OPT.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

All relevant versions of Leptonica support pkg-config, so the old
configuration code can be removed.

Update also the error message for missing Leptonica.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

The old settings don't work for cross compilations (wrong include path)
or require setting LIBLEPT_HEADERSDIR. They are used as fallback if
there is no pkg-config configuration.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

The old settings are used as fallback if there is no configuration.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

Builds without support for OpenMP failed with the old code. Fix this:

* Add OPENMP_CXXFLAGS for ccmain.
* Replace unconditional -fopenmp by OPENMP_CXXFLAGS for lstm.
* Always use _OPENMP for conditional compilation.
* Remove OPENMP as there is already _OPENMP.
* Include omp.h conditionally.
Signed-off-by: NStefan Weil <sw@weilnetz.de>

openclwrapper calls function TIFFReadRGBAImageOriented which is provided
by libtiff, so add that library to OPENCL_LIBS.

This fixes a linker error (unresolved symbol) when opencl is enabled.
Signed-off-by: NStefan Weil <sw@weilnetz.de>