How to link my app statically against ICU 57.1 MinGW - c++

Question

I've built ICU 57.1 statically with MinGW x32;
As a result, I got the following files in the lib directory:
libsicudt.a
libsicuin.a
libsicuio.a
libsicule.a
libsiculx.a
libsicutest.a
libsicutu.a
libsicuuc.a
sicudt.a
sicudt.dll
Now I want to run one of the examples, but whatever I try it
I receive errors like
"undefined reference to unum_...
unum_setAttribute
unum_formatInt64
u_isspace".
Total number of errors at the beginning was about 1700.
Analyzing pkgconfig files I figured out some mutual dependencies and
after reordering .a files in cmd line reduced errors to 82.
But I have no idea where to go next.
Google shows that many people have same problem with ICU but
so far there is no solution that works for me and explains the cause.
When building, I use Qt Creator for convenience, here is my .pro file:
TEMPLATE = app
CONFIG += console c++11
CONFIG -= app_bundle
CONFIG -= qt
SOURCES += main.cpp
ICUDIR=$$(ICU_PATH)
ICU_LIBPATH=$$ICUDIR"/dist/lib/"
INCLUDEPATH += $$ICUDIR"/dist/include"
LIBS += $$ICU_LIBPATH"libsicuuc.a" $$ICU_LIBPATH"libsicudt.a" \
$$ICU_LIBPATH"libsicuin.a" $$ICU_LIBPATH"libsicuio.a" \
$$ICU_LIBPATH"libsicule.a" $$ICU_LIBPATH"libsiculx.a" \
$$ICU_LIBPATH"libsicutu.a" $$ICU_LIBPATH"sicudt.a"
I have following questions:
1) Can anybody write a simple one line command that statically builds
the simpliest ICU app using g++? Is it even possible?
2) What is the correct order of .a files when passing them to linker?
3) What are files libsicudt.a, sicudt.a and sicudt.dll inteded for?
4) Is the file list I wrote above complete or my build is corrupt?
5) Is there anything I've missed of doing wrong?

Answer 1

Finally, I solved the problem. In order to share my experiece with you
I will describe four major pitfalls that I've encountered.
I assume that you use msys2 and MinGW-w32 if you want to repeat the steps.
Use same toolchain for everything. Note that MinGW, MinGW-w32 and MinGW-w64
are 3 different toolchains. If you have multiple installations of MinGW
like me, make sure that you use only one of them for the entire project.
I chose MinGW-w32 for compatibility reasons.
The newest versions of software often contain bugs, and they
require from you some more dancing with tambourins.
ICU v58 was buggy at the moment of writing this post.
The solution is to revert to an older version (57.1 in my case).
Before building ICU library, make sure to setup everything correctly.
Here problem is with using namespaces and renaming namespaces which
ICU does by default.
Find file C:\icu\source\common\unicode\uconfig.h and add the following
at the beginning after include guards:
#define U_DISABLE_RENAMING 1
#define U_USING_ICU_NAMESPACE 0
Save the file. Open MSYS2 terminal and set mingw-w32 as working toolset:
export PATH="/c/msys64/mingw32/bin:$PATH"
Go to icu/source dir:
cd /c/icu/source
Configure ICU for static build with no renaming and U_USING_ICU_NAMESPACE=0:
export CFLAGS="-DU_CHARSET_IS_UTF8=1 -DU_GNUC_UTF16_STRING=1 -DU_STATIC_IMPLEMENTATION"
export CXXFLAGS="-DU_USING_ICU_NAMESPACE=0 -std=gnu++11 -DU_CHARSET_IS_UTF8=1 -DU_GNUC_UTF16_STRING=1 -DU_HAVE_CHAR16_T=1 -DUCHAR_TYPE=char16_t -Wall --std=c++11 -DU_STATIC_IMPLEMENTATION" -static-libstdc++ -fno-exceptions
export CPPFLAGS="-DU_DISABLE_RENAMING=1 -DU_CHARSET_IS_UTF8=1 -DU_STATIC_IMPLEMENTATION"
export LDFLAGS="-std=gnu++11"
./runConfigureICU MinGW prefix=$PWD/../dist -enable-static -disable-shared --disable-renaming
Build and install ICU lib. -j4 speeds up the process if you have 4 cores:
mingw32-make -j4
mingw32-make install
Cleanup intermediate files:
mingw32-make clean
Now you should have static libraries located at icu/dist/lib .
PITFALL 4: when linking statically, you should pass libraries to
linker in correct order. That matters only for static linking.
But how to figure out which order is correct?
Here pkg-config tool comes handy.
What it does is the following: takes library package names as
parameter, calculates dependencies and returns the complete string
of parameters that can be fed directly to the compiler
or viewed by you to understand what's going on under the hood.
There are 5 packages located at C:\icu\dist\lib\pkgconfig.
Let's configure path for pkg-config:
export PKG_CONFIG_PATH="/c/icu/dist/lib/pkgconfig:$PKG_CONFIG_PATH"
In order to test it, type:
pkg-config --static --cflags --libs icu-uc icu-i18n icu-io icu-le icu-lx
The output should be:
-IC:/icu/dist/include -LC:/icu/dist/lib -lsicuio -lsicuin -lsiculx -lsicule -lsicuuc -lsicudt -lpthread -lm
That's the string we have to pass to compiler.
As final test, we will compile a simple example app using command line:
Create folder /c/icu/dist/test with file test.cpp inside:
#include <unicode/unistr.h>
#include <unicode/ustdio.h>
#include <unicode/brkiter.h>
#include <stdlib.h>
using namespace icu;
void printUnicodeString(UFILE *out, const UnicodeString &s) {
UnicodeString other = s;
u_fprintf(out, "\"%S\"", other.getTerminatedBuffer());
}
int main( void )
{
UFILE *out;
UErrorCode status = U_ZERO_ERROR;
out = u_finit(stdout, NULL, NULL);
if(!out) {
fprintf(stderr, "Could not initialize (finit()) over stdout! \n");
return 1;
}
ucnv_setFromUCallBack(u_fgetConverter(out), UCNV_FROM_U_CALLBACK_ESCAPE,
NULL, NULL, NULL, &status);
if(U_FAILURE(status)) {
u_fprintf(out, "Warning- couldn't set the substitute callback - err %s\n", u_errorName(status));
}
/* End Demo boilerplate */
u_fprintf(out,"ICU Case Mapping Sample Program\n\n");
u_fprintf(out, "C++ Case Mapping\n\n");
UnicodeString string("This is a test");
u_fprintf(out, "\nstring: ");
printUnicodeString(out, string);
string.toUpper(); /* string = "THIS IS A TEST" */
u_fprintf(out, "\ntoUpper(): ");
printUnicodeString(out, string);
return 0;
}
Go to the test dir:
cd /c/icu/dist/test
g++ -o test test.cpp \
`pkg-config --cflags --libs --static icu-uc icu-i18n icu-io icu-le icu-lx`
Run the app:
./test
Maybe this is not the best way to do,
especially concerning workspaces, but it works.
More about pgk-config here:
https://people.freedesktop.org/~dbn/pkg-config-guide.html