C / C++ / MFC

Re: GCC ` backtick` CLI - what does it actually do ?

16-Jul-20 14:30

SOLVED case closed
As expected - pkg-config DOES NOT integrate with just any Eclipse version / release.
I got it working as expected in 2018-09!
Sorry for wasting everybody time.
Cheers

It is my understanding that the characters enclosed in backticks execute and the result is passed as option(s) to the GCC.

`pkg-config --cflags gtk+-3.0`

I have added the backticks string to both GCC compiler and linkers options and still getting the usual "undefined reference" error.
The tutorial does not explain much about implementing this backticks string.
(Should it add library -l refernces ??)

I woudl appreciate references or comments on this and suggestions how to actually resolve this issue.

I am enclosing the complier / liker verbose output for information, and I am sorry to take so much bandwidth with it.

Cheers

CODE DELETED

Addendum
I do not like blaming problems elsewhere, BUT,
this problem is really not related to using backtick syntax. After some trials it works as expected.

There were few other problems AFTER I updated to latest version of IDE. So I down paddled to previous, working release and imported the GTK project there.

Just build a clean GTK project and it works as expected.

I am sorry for wasting everybody time with a problem related to flaky IDE.

Cheers

modified 22-Jul-20 13:07pm.

Peter_in_278016-Jul-20 15:44

Peter_in_2780

16-Jul-20 15:44

Run your backticked phrase (without backticks), redirected to a file. Then you can see what it injects into your command line when it's used backticked.
Something like

pkg-config --cflags gtk+-3.0 > lookatmeclosely

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

Re: GCC ` backtick` CLI - what does it actually do ?

Vaclav_16-Jul-20 15:57

Re: GCC ` backtick` CLI - what does it actually do ?

16-Jul-20 15:57

Thanks, but I know what is does - look at all the -I in the attached file. I think g++ also needs -l - libraries or library - for GTK.
But I am not sure how to do it if I need more.
Can I use similar method
as pkg-config to get -l /-L ?

Addendum

Did some research and found this

z@z-desktop Unsure | :~

$ pkg-config --libs gtk+-3.0
-lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0

That is what is needed.

However adding another backtick string `pkg-config --libs gtk+-3.0` did not produced expected libraries.

Will do some experimentation with that - it should work.

More edit

If I add
`pkg-config --libs gtk+-3.0` to linker options I get about 20 additional -l libraries in output.

However I still get "undefined reference " error.
Later...

modified 16-Jul-20 22:43pm.

k505417-Jul-20 3:53

k5054

17-Jul-20 3:53

Make sure you are adding the --libs option to the link phase in your IDE. e.g.
compiler flags : ... `pkg-config --cflags gtk+-3.0` ...
linker flags : ... `pkg-config --libs gtk+-3.0` ...

As an aside, you should be aware that the backtick idiom is a shell level construct, and is not anything specific to gcc. so you could do the following :

$ ls -l `find . -name *.cpp`

Which would produce a long listing of all cpp files in the current directory tree.

Keep Calm and Carry On

Re: GCC ` backtick` CLI - what does it actually do ?

Vaclav_17-Jul-20 4:55

Re: GCC ` backtick` CLI - what does it actually do ?

17-Jul-20 4:55

OK, putting wrong option may be one of the issues.
I did put BOTH --cflag and --libs in complier and linker options. I also tried
this combined syntax
`pkg-config --cflags --libs gtk+-3.0`

The compiler and linker verbose outputs looks OK ( too big to repost here ) , BUT the unresolved error is apparently different issue.

I am enclosing what I posted in Eclipse forum here:

This error has been posted years ago and there was NO SOLUTION,

See this old post

[b]However, this only solved the issue of adding all the header files manually. Now I encounter errors like "Function 'G_CALLBACK' could not be resolved". I tried to compile my source-code (the first example of the GTK3 tutorial) in a terminal using the simple "gcc `pkg-config --cflags gtk+-3.0` -o example-0 First_GTK_test.cpp `pkg-config --libs gtk+-3.0`" command and it works. So the issue must be an Eclipse setting issue.[/b]

Every GTK tutorial is same - download / install GTK and run sample code in your editor...

It is up to the user to figure out how to option complier / linker to "include sources and link libraries"
Adding `pkg-config --cflags --libs gtk+-3.0` should work, I get expected verbose output , but it does not.
Even after that is done the compilation will fail because #include <gtk gtk.h=""> is unresolved.

Here is an output of whereis

z@z-desktop Unsure | :~

$ whereis gtk.h
gtk:
z@z-desktop Unsure | :~

$

Any help woudl be appreciated
End of Eclipse post.

I am really at lost where the reference
<gtk gtk.h=""> came from and unsure how to find gtk.h manually - where ?

Appreciate all the help with such trivial issue.

Cheers

Vaclav_17-Jul-20 5:19

Re: GCC ` backtick` CLI - what does it actually do ?

17-Jul-20 5:19

OK, this makes no sense
Eclipse IDE has under includes
/usr/include

BUT
I had to add this full path manually to get rid of " file doe snot exist " AKA undefined reference

#include /usr/include/gtk-3.0/gtk/gtk.h
( < > won't show !!!! )

Now my first usage of GTK gives the "undefined reference " error - same as the very old post on Eclipse.

In my view - the "top reference" is OK, but anything "bellow" is still unreferenced.

This is a mess...

k505417-Jul-20 5:38

k5054

17-Jul-20 5:38

I'm fairly sure that the "undefined reference" is a link phase error, not a compile phase problem, so I don't think changing the headers or header search path will not help you

Vaclav_ wrote:
Eclipse IDE has under includes
/usr/include

I don't use eclipse, but it looks to me like that's a path, so I think you would add
/usr/include/gtk-3.0
assuming you're adding #include <gtk gtk.h=""> to your source file

If you're getting the object files compiled successfully, but not getting the linking done then try, from a command line

gcc file1.o file2.o ... `pkg-config --libs gtk+-3.0` -o myapp

if you're compiling C++ code, use g++ to link, not gcc, as that will link in stdlib++.o, and do anything else that C++ needs that plain C doesn't

I don't see where you've said exactly what the undefined reference you're getting is. Its possible that its not a gtk+ function, but maybe a math (eg. abs, ceil cos) or function from another library.

Keep Calm and Carry On

Re: GCC ` backtick` CLI - what does it actually do ?

Vaclav_17-Jul-20 6:05

Re: GCC ` backtick` CLI - what does it actually do ?

17-Jul-20 6:05

I am including , again, full complier / linker output. This is for purpose of discussion , I hope I can delete it later.

Here is a full verbose output of complier and linker, note slew of "includes".
In theory #include /gtk/gtk.h should work.

If the error is flagged in IDE as " file not accessible" does it really matters if it is complier or linker error?

( The Eclipse refers to complier as "Linux GCC" then as "GCC C++ Complier" however the actuall options string starts with "g++". Semantics???)

10:50:35 **** Build of configuration Debug for project GTK_WIKI ****
make all
Building file: ../src/GTK_WIKI.cpp
Invoking: GCC C++ Compiler
g++ -I/usr/include/gtk-3.0/gtk -O0 -g3 -Wall -c -fmessage-length=0 `pkg-config --cflags --libs gtk+-3.0` -v -MMD -MP -MF"src/GTK_WIKI.d" -MT"src/GTK_WIKI.o" -o "src/GTK_WIKI.o" "../src/GTK_WIKI.cpp"
Using built-in specs.
COLLECT_GCC=g++
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.0-6ubuntu1~16.04.12' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
COLLECT_GCC_OPTIONS='-I' '/usr/include/gtk-3.0/gtk' '-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-pthread' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/at-spi2-atk/2.0' '-I' '/usr/include/at-spi-2.0' '-I' '/usr/include/dbus-1.0' '-I' '/usr/lib/x86_64-linux-gnu/dbus-1.0/include' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/gio-unix-2.0/' '-I' '/usr/include/mirclient' '-I' '/usr/include/mircore' '-I' '/usr/include/mircookie' '-I' '/usr/include/cairo' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/harfbuzz' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/atk-1.0' '-I' '/usr/include/cairo' '-I' '/usr/include/pixman-1' '-I' '/usr/include/freetype2' '-I' '/usr/include/libpng12' '-I' '/usr/include/gdk-pixbuf-2.0' '-I' '/usr/include/libpng12' '-I' '/usr/include/glib-2.0' '-I' '/usr/lib/x86_64-linux-gnu/glib-2.0/include' '-v' '-MMD' '-MP' '-MF' 'src/GTK_WIKI.d' '-MT' 'src/GTK_WIKI.o' '-o' 'src/GTK_WIKI.o' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/5/cc1plus -quiet -v -I /usr/include/gtk-3.0/gtk -I /usr/include/gtk-3.0 -I /usr/include/at-spi2-atk/2.0 -I /usr/include/at-spi-2.0 -I /usr/include/dbus-1.0 -I /usr/lib/x86_64-linux-gnu/dbus-1.0/include -I /usr/include/gtk-3.0 -I /usr/include/gio-unix-2.0/ -I /usr/include/mirclient -I /usr/include/mircore -I /usr/include/mircookie -I /usr/include/cairo -I /usr/include/pango-1.0 -I /usr/include/harfbuzz -I /usr/include/pango-1.0 -I /usr/include/atk-1.0 -I /usr/include/cairo -I /usr/include/pixman-1 -I /usr/include/freetype2 -I /usr/include/libpng12 -I /usr/include/gdk-pixbuf-2.0 -I /usr/include/libpng12 -I /usr/include/glib-2.0 -I /usr/lib/x86_64-linux-gnu/glib-2.0/include -imultiarch x86_64-linux-gnu -MMD src/GTK_WIKI.d -MF src/GTK_WIKI.d -MP -MT src/GTK_WIKI.o -dD -D_GNU_SOURCE -D_REENTRANT ../src/GTK_WIKI.cpp -quiet -dumpbase GTK_WIKI.cpp -mtune=generic -march=x86-64 -auxbase-strip src/GTK_WIKI.o -g3 -O0 -Wall -version -fmessage-length=0 -fstack-protector-strong -Wformat-security -o /tmp/ccPz2oLW.s
GNU C++ (Ubuntu 5.4.0-6ubuntu1~16.04.12) version 5.4.0 20160609 (x86_64-linux-gnu)
compiled by GNU C version 5.4.0 20160609, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/5"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/5/../../../../x86_64-linux-gnu/include"
ignoring duplicate directory "/usr/include/gtk-3.0"
ignoring duplicate directory "/usr/include/pango-1.0"
ignoring duplicate directory "/usr/include/cairo"
ignoring duplicate directory "/usr/include/libpng12"
#include "..." search starts here:
#include <...> search starts here:
/usr/include/gtk-3.0/gtk
/usr/include/gtk-3.0
/usr/include/at-spi2-atk/2.0
/usr/include/at-spi-2.0
/usr/include/dbus-1.0
/usr/lib/x86_64-linux-gnu/dbus-1.0/include
/usr/include/gio-unix-2.0/
/usr/include/mirclient
/usr/include/mircore
/usr/include/mircookie
/usr/include/cairo
/usr/include/pango-1.0
/usr/include/harfbuzz
/usr/include/atk-1.0
/usr/include/pixman-1
/usr/include/freetype2
/usr/include/libpng12
/usr/include/gdk-pixbuf-2.0
/usr/include/glib-2.0
/usr/lib/x86_64-linux-gnu/glib-2.0/include
/usr/include/c++/5
/usr/include/x86_64-linux-gnu/c++/5
/usr/include/c++/5/backward
/usr/lib/gcc/x86_64-linux-gnu/5/include
/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu/5/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
GNU C++ (Ubuntu 5.4.0-6ubuntu1~16.04.12) version 5.4.0 20160609 (x86_64-linux-gnu)
compiled by GNU C version 5.4.0 20160609, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 85af4995304287cdd19cfa43cf5d6cf1
../src/GTK_WIKI.cpp: In function 'int main(int, char**)':
../src/GTK_WIKI.cpp:30:16: warning: variable 'window' set but not used [-Wunused-but-set-variable]
GtkWidget *window;
^
../src/GTK_WIKI.cpp:31:16: warning: unused variable 'label' [-Wunused-variable]
GtkWidget *label;
^
COLLECT_GCC_OPTIONS='-I' '/usr/include/gtk-3.0/gtk' '-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-pthread' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/at-spi2-atk/2.0' '-I' '/usr/include/at-spi-2.0' '-I' '/usr/include/dbus-1.0' '-I' '/usr/lib/x86_64-linux-gnu/dbus-1.0/include' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/gio-unix-2.0/' '-I' '/usr/include/mirclient' '-I' '/usr/include/mircore' '-I' '/usr/include/mircookie' '-I' '/usr/include/cairo' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/harfbuzz' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/atk-1.0' '-I' '/usr/include/cairo' '-I' '/usr/include/pixman-1' '-I' '/usr/include/freetype2' '-I' '/usr/include/libpng12' '-I' '/usr/include/gdk-pixbuf-2.0' '-I' '/usr/include/libpng12' '-I' '/usr/include/glib-2.0' '-I' '/usr/lib/x86_64-linux-gnu/glib-2.0/include' '-v' '-MMD' '-MP' '-MF' 'src/GTK_WIKI.d' '-MT' 'src/GTK_WIKI.o' '-o' 'src/GTK_WIKI.o' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
as -v -I /usr/include/gtk-3.0/gtk -I /usr/include/gtk-3.0 -I /usr/include/at-spi2-atk/2.0 -I /usr/include/at-spi-2.0 -I /usr/include/dbus-1.0 -I /usr/lib/x86_64-linux-gnu/dbus-1.0/include -I /usr/include/gtk-3.0 -I /usr/include/gio-unix-2.0/ -I /usr/include/mirclient -I /usr/include/mircore -I /usr/include/mircookie -I /usr/include/cairo -I /usr/include/pango-1.0 -I /usr/include/harfbuzz -I /usr/include/pango-1.0 -I /usr/include/atk-1.0 -I /usr/include/cairo -I /usr/include/pixman-1 -I /usr/include/freetype2 -I /usr/include/libpng12 -I /usr/include/gdk-pixbuf-2.0 -I /usr/include/libpng12 -I /usr/include/glib-2.0 -I /usr/lib/x86_64-linux-gnu/glib-2.0/include --64 -o src/GTK_WIKI.o /tmp/ccPz2oLW.s
GNU assembler version 2.26.1 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.26.1
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/5/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-I' '/usr/include/gtk-3.0/gtk' '-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-pthread' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/at-spi2-atk/2.0' '-I' '/usr/include/at-spi-2.0' '-I' '/usr/include/dbus-1.0' '-I' '/usr/lib/x86_64-linux-gnu/dbus-1.0/include' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/gio-unix-2.0/' '-I' '/usr/include/mirclient' '-I' '/usr/include/mircore' '-I' '/usr/include/mircookie' '-I' '/usr/include/cairo' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/harfbuzz' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/atk-1.0' '-I' '/usr/include/cairo' '-I' '/usr/include/pixman-1' '-I' '/usr/include/freetype2' '-I' '/usr/include/libpng12' '-I' '/usr/include/gdk-pixbuf-2.0' '-I' '/usr/include/libpng12' '-I' '/usr/include/glib-2.0' '-I' '/usr/lib/x86_64-linux-gnu/glib-2.0/include' '-v' '-MMD' '-MP' '-MF' 'src/GTK_WIKI.d' '-MT' 'src/GTK_WIKI.o' '-o' 'src/GTK_WIKI.o' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
Finished building: ../src/GTK_WIKI.cpp

Building target: GTK_WIKI
Invoking: GCC C++ Linker
g++ -v `pkg-config --cflags --libs gtk+-3.0` -o "GTK_WIKI" ./src/GTK_WIKI.o
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.0-6ubuntu1~16.04.12' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/5/:/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/5/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-pthread' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/at-spi2-atk/2.0' '-I' '/usr/include/at-spi-2.0' '-I' '/usr/include/dbus-1.0' '-I' '/usr/lib/x86_64-linux-gnu/dbus-1.0/include' '-I' '/usr/include/gtk-3.0' '-I' '/usr/include/gio-unix-2.0/' '-I' '/usr/include/mirclient' '-I' '/usr/include/mircore' '-I' '/usr/include/mircookie' '-I' '/usr/include/cairo' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/harfbuzz' '-I' '/usr/include/pango-1.0' '-I' '/usr/include/atk-1.0' '-I' '/usr/include/cairo' '-I' '/usr/include/pixman-1' '-I' '/usr/include/freetype2' '-I' '/usr/include/libpng12' '-I' '/usr/include/gdk-pixbuf-2.0' '-I' '/usr/include/libpng12' '-I' '/usr/include/glib-2.0' '-I' '/usr/lib/x86_64-linux-gnu/glib-2.0/include' '-o' 'GTK_WIKI' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/5/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/5/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper -plugin-opt=-fresolution=/tmp/ccECrhXv.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lpthread -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --sysroot=/ --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -z relro -o GTK_WIKI /usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/5/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/5 -L/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/5/../../.. -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 ./src/GTK_WIKI.o -lstdc++ -lm -lgcc_s -lgcc -lpthread -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/5/crtend.o /usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crtn.o
makefile:45: recipe for target 'GTK_WIKI' failed
./src/GTK_WIKI.o: In function `main':
/media/z/DEV_COPY_LABEL/ECLIPSE_FOLDER/2020_228/work_228/GTK_WIKI/Debug/../src/GTK_WIKI.cpp:49: undefined reference to `gtk_window_new'
collect2: error: ld returned 1 exit status
make: *** [GTK_WIKI] Error 1
"make all" terminated with exit code 2. Build might be incomplete.

10:50:37 Build Failed. 3 errors, 2 warnings. (took 2s.689ms)

Richard MacCutchan17-Jul-20 6:19

Re: GCC ` backtick` CLI - what does it actually do ?

17-Jul-20 6:19

The undefined ref is gtk_window_new defined in GtkWindow: GTK+ 3 Reference Manual[^]. No idea what OP is trying to do, as usual he has not explained.

k505417-Jul-20 6:57

k5054

17-Jul-20 6:57

How did you pick that up? I copied the entire output posted at the top of this thread, and
a) a search for "undefined" turned up nothing, and
b) as currently shown, the compile completes successfully!!
Doing a quick perusal of the rest of the thread, I didn't notice any further mention of exactly what was undefined.
At this point, I have no idea what the problem is, since it looks to me like the compile/link is correct - -lgtk-3 is in the link options. Maybe Eclipse is doing something odd.

Keep Calm and Carry On

Undefined reference GTK issue was Re: GCC ` backtick` CLI - what does it actually do ?

Vaclav_17-Jul-20 7:35

Re: GCC ` backtick` CLI - what does it actually do ?

17-Jul-20 7:35

Here is the part of actual code

#include /usr/include/gtk-3.0/gtk/gtk.h // edited so it show
int main (int argc, char *argv[])
{
GtkWidget *window;
GtkWidget *label;
cout << "WINDOW sample code" << endl; // prints
/* Create the main, top level window */
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

And here is the tail of the compile / link process

./src/GTK_WIKI.o: In function `main':
/media/z/DEV_COPY_LABEL/ECLIPSE_FOLDER/2020_228/work_228/GTK_WIKI/Debug/../src/GTK_WIKI.cpp:49: undefined reference to `gtk_window_new'
collect2: error: ld returned 1 exit status
makefile:45: recipe for target 'GTK_WIKI' failed
make: *** [GTK_WIKI] Error 1
"make all" terminated with exit code 2. Build might be incomplete.

12:30:58 Build Failed. 3 errors, 2 warnings. (took 2s.647ms)

Any actual , constructive help to solve the problem is appreciated.

Cheers

Richard MacCutchan17-Jul-20 21:54

Re: Develop VC++ for IPad

17-Jul-20 21:54

It was right at the end of the build output in the previous message:

/media/z/DEV_COPY_LABEL/ECLIPSE_FOLDER/2020_228/work_228/GTK_WIKI/Debug/../src/GTK_WIKI.cpp:49: undefined reference to `gtk_window_new'
collect2: error: ld returned 1 exit status
make: *** [GTK_WIKI] Error 1
"make all" terminated with exit code 2. Build might be incomplete.

10:50:37 Build Failed. 3 errors, 2 warnings. (took 2s.689ms)

Did you search the original which did not have any errors?

I can only assume that there is an object file or library missing from the build.

[edit]
I have also tried to explain a number of times to OP that adding header files to a build has no effect on linker errors.
[/edit]

Develop VC++ for IPad

_Flaviu15-Jul-20 7:01

_Flaviu

15-Jul-20 7:01

I need to put code from my MFC app into a C++ app for iPad. And I have read a lot to figure out what should I use to develop such a thing. Can I call your experience in order to guide me what kind of framework to use for that ? I thought the shortest way is to use a virtual machine, but I don't think that it would be possible to use virtual machine on a iPad ...

I don't developed any app for MAC OS and any extra information regarding this is useful to me.

Thank you.

Richard MacCutchan15-Jul-20 22:56

Re: Develop VC++ for IPad

15-Jul-20 22:56

Take a look at Xamarin.iOS - Hello iPad - Code Samples | Microsoft Docs[^].

_Flaviu16-Jul-20 0:56

_Flaviu

16-Jul-20 0:56

Yes, but I saw there C# code, not C++ ... and I need C++, I don't know C# at all.

Re: Develop VC++ for IPad

Richard MacCutchan16-Jul-20 1:37

FFMPEG encrypt & decrypt Video offline

16-Jul-20 1:37

See Android and iOS development with C++ in Visual Studio | C++ Team Blog[^]. There are various other resources that Google will find on the subject.

DARA ALAVI13-Jul-20 21:50

DARA ALAVI

13-Jul-20 21:50

I want encrypt & decrypt Video file With FFMPEG oflfine mode in hard disk.

I encrypt a Video File (mp4 Extention) by ffmpeg.exe Tools by this Command:

C++

ffmpeg -i SampleVideo_1280x720_1mb.mp4 -vcodec copy -acodec copy
-encryption_scheme cenc-aes-ctr -encryption_key
76a6c65c5ea762046bd749a2e632ccbb -encryption_kid
a7e61c373e219033c21091fa607bf3b8 SampleVideo_1280x720_1mb_encrypted.mp4

for decryption : i want decrypt and play video file (encrypted.mp4) in my player source c++ (ffmpeg base) and *now i dont wnat use decrypt file with command line with ffplay.exe *like this :

C++

ffplay SampleVideo_1280x720_1mb_encrypted.mp4 -decryption_key
76a6c65c5ea762046bd749a2e632ccbb

how i can do decrypt with Write programing code that use FFMPEG api?

thanks in advance.

Victor Nijegorodov13-Jul-20 21:55

Victor Nijegorodov

13-Jul-20 21:55

DARA ALAVI wrote:
how i can do decrypt with Write programing code that use FFMPEG api?

Read/learn the FFMPEG api documentation.

DARA ALAVI13-Jul-20 22:09

DARA ALAVI

13-Jul-20 22:09

I searched a lot but did not find anything.
There is no explanation on how to use it. Frown | :(

I did not find a sample.. Frown | :(

Victor Nijegorodov13-Jul-20 22:23

Victor Nijegorodov

13-Jul-20 22:23

Then use the recommended way to decrypt with ffplay.exe

Does FreeRTOS have built-in support for queues that can hold variable sized elements?

DARA ALAVI13-Jul-20 22:38

DARA ALAVI

13-Jul-20 22:38

I do not need ffplay.exe because i downloaded FFMPEG dev and i have written my own player program Which is based on FFMPEG! with QT & C++.
I dont want use ffplay.exe that exist static FFMPEG Folder. .
I want decrypt and play Encrypted File in my player program Through Programing code.

Now how to decrypt encrypted files using FFMPeg API with C++ Programing?
thanks.

arnold_w12-Jul-20 10:06

arnold_w

12-Jul-20 10:06

I need to debug some code executing on top of FreeRTOS that runs on an embedded ARM processor and I have no knowledge of FreeRTOS and I was hoping someone here could please help me. Image there are two threads in the entire code, one high-priority communication bus driver and one low-priority application thread. Whenever the application wants to write, it queues a struct onto a queue and when the communication driver sees that there is a struct in the queue, it pulls the struct out and starts writing over the communication bus according to the instructions in the struct. Now, let's assume the application first wants to write 1 byte and then shortly thereafter wants to write 2 bytes and the bytes to write are located on the stack and NOT in static variables/arrays. What the recommended way to handle this? Clearly the 2nd struct would be 1 byte larger than the 1st struct, but they both need to go into the same queue.

modified 12-Jul-20 16:14pm.

Re: Does FreeRTOS have built-in support for queues that can hold variable sized elements?

Richard MacCutchan12-Jul-20 21:14