Eclipse CDT, cygwin and linking problems

[Gotch@]

Hi all,
I've installed the CDT plugin for Eclipse and I want to use it to work
on C/C++ projects under Cygwin. It works, in fact it compiles and runs
the usual helloworld c++ program. Now it comes difficult when I try to
add external libs. Such as... GTK. Let's explain what I tried. (oh
well, I'm using Eclipse Europa 3.3.1 and CDT 4.0.1). First I just
added the path of the cygwin includes throug the project->properties-

C/C++ General->Paths and Symbols window. I added in Includes under

GNU C the path to the gtk-2.0 includes in cygwin/usr/include/gtk-2.0
folder. No effect. It says that it couldn't find gtk/gtk.h . So, since
it's a C++ project, I tried to add them under GNU C++. As a result the
compiler starts putting out messages about every header in the library
compelling that ISO C forbids this and that...
Let's note that my include is
#include <gtk/gtk.h> but i get the same results with <gtk.h> and "gtk/
gtk.h".

I don't get it, but I'd like to use eclipse to devlop in C/C++ because
of positive Java experiences.

Do you have any ideas, most tutorials on the topic are outdated and
the old CDT is quite different, especially regarding the project
types.

 

[jacob navia]

Hi all,
I've installed the CDT plugin for Eclipse and I want to use it to work
on C/C++ projects under Cygwin. It works, in fact it compiles and runs
the usual helloworld c++ program. Now it comes difficult when I try to
add external libs. Such as... GTK. Let's explain what I tried. (oh
well, I'm using Eclipse Europa 3.3.1 and CDT 4.0.1). First I just
added the path of the cygwin includes throug the project->properties-
GNU C the path to the gtk-2.0 includes in cygwin/usr/include/gtk-2.0
folder. No effect. It says that it couldn't find gtk/gtk.h .

You addedd the path to
/usr/include/gtk-2.0 BUT the code expects
/usr/include/gtk

Try to make a symbolic link of gtk-2.0 to gtk

 

[Gotch@]

The symlink is not seen by Windows file access routines... I'll try to
just rename the folder... hope this wuoldn't break up anything...

 

[Keith Thompson]

The symlink is not seen by Windows file access routines... I'll try to
just rename the folder... hope this wuoldn't break up anything...

Your question is about Cygwin, Eclipse, and CDT, not about the C
programming language. If you want help, you should ask in a forum
where these things are topical. Possibly one of the Cygwin mailing
lists would be helpful (see www.cygwin.com), or perhaps a forum that
deals with Eclipse.

 

[Flash Gordon]

Gotch@ wrote, On 15/01/08 17:17:

The symlink is not seen by Windows file access routines... I'll try to
just rename the folder... hope this wuoldn't break up anything...

<snip>

This is not topical here for two reasons
1) You state you are using C++, that is not the language we discuss here
2) Your problem is with your tools rather than the language.

I'm sure there are Eclipse mailing lists, I suggest you try checking
them out, finding the correct one, and asking there. Or possibly on the
gcc, Cygwin or GTK mailing lists, as your problem might be with those
rather than Eclipse itself. However *check* what is topical before
posting your question somewhere else.

 

[jacob navia]

Gotch@ wrote, On 15/01/08 17:17:

<snip>

This is not topical here for two reasons
1) You state you are using C++, that is not the language we discuss here
2) Your problem is with your tools rather than the language.

I'm sure there are Eclipse mailing lists, I suggest you try checking
them out, finding the correct one, and asking there. Or possibly on the
gcc, Cygwin or GTK mailing lists, as your problem might be with those
rather than Eclipse itself. However *check* what is topical before
posting your question somewhere else.

Actually it is a language problem

He added
\include\gtk-2.0 (what is equivalent to calling the compiler
with -I\include\gtk-2.0) but the source code expects
\include\gtk.

Note that when you write
#include <gtk/gtk.h>
the language supposes that directories exist and that there
is a subdirectory "gtk" in the normal system includes
directory. The user had a problem with the spelling of the path, not
with Eclipse/C++/whatever

I expect that in a group about C we can give people a hand
spotting those errors that are trivial, but somehow our
brain refuses to see.

How many times I have misspelled a variable and couldn't
find the error?

 

[CJ]

How many times I have misspelled a variable and couldn't
find the error?

Perhaps you should switch to a compiler that issues a useful diagnostic
message for undeclared variables?

 

[jacob navia]

Perhaps you should switch to a compiler that issues a useful diagnostic
message for undeclared variables?

If the variable wasn't defined. The *real* problem is when you
have some variable that *is* defined but it is not the one
you want.

 

[Keith Thompson]

Actually it is a language problem

He added
\include\gtk-2.0 (what is equivalent to calling the compiler
with -I\include\gtk-2.0) but the source code expects
\include\gtk.

Note that when you write
#include <gtk/gtk.h>
the language supposes that directories exist and that there
is a subdirectory "gtk" in the normal system includes
directory.

[...]

The *language* does no such thing; an implementation very likely does.

C99 6.10.2p2:

A preprocessing directive of the form

# include <h-char-sequence> new-line

searches a sequence of implementation-defined places for a header
identified uniquely by the specified sequence between the < and >
delimiters, and causes the replacement of that directive by the
entire contents of the header. How the places are specified or the
header identified is implementation-defined.

Note the lack of any mention of directories or subdirectories, or of
any implication that '/' is a directory path delimiter.

Even if you think this is nitpicking, that it's obvious that <gtk/...>
must refer to a directory named "gtk", it's not at all obvious what
the proper solution is. I doubt that either creating a symlink or
renaming the folder is the right approach.

<OT>

You wrote:

You addedd the path to
/usr/include/gtk-2.0 BUT the code expects
/usr/include/gtk

Try to make a symbolic link of gtk-2.0 to gtk

But in fact, on my Cygwin installation the header file the OP is
looking for is at /usr/include/gtk-2.0/gtk/gtk.h (note that "gtk" is a
subdirectory of "gtk-2.0"().

My best guess is that the problem is a confusion between Windows and
Cygwin paths (the directory "/usr/include/gtk-2.0" as seen from Cygwin
might be called, for example, "C:\cygwin\usr\include\gtk-2.0" as seen
from Windows). If that's the problem, a Cygwin mailing list would
be the best place to ask about it.

</OT>

 

[Kelsey Bjarnason]

If the variable wasn't defined. The *real* problem is when you
have some variable that *is* defined but it is not the one
you want.

I'd tend to think that if you're encountering this, your choice of
variable names is perhaps more at fault than anything, no?

 

[qaiser.mohammad]

Hi all,
I've installed the CDT plugin for Eclipse and I want to use it to work
on C/C++ projects under Cygwin. It works, in fact it compiles and runs
the usual helloworld c++ program. Now it comes difficult when I try to
add external libs. Such as... GTK. Let's explain what I tried. (oh
well, I'm using Eclipse Europa 3.3.1 and CDT 4.0.1). First I just
added the path of the cygwin includes throug the project->properties->C/C++ General->Paths and Symbols window. I added in Includes under

GNU C the path to the gtk-2.0 includes in cygwin/usr/include/gtk-2.0
folder. No effect. It says that it couldn't find gtk/gtk.h . So, since
it's a C++ project, I tried to add them under GNU C++. As a result the
compiler starts putting out messages about every header in the library
compelling that ISO C forbids this and that...
Let's note that my include is
#include <gtk/gtk.h> but i get the same results with <gtk.h> and "gtk/
gtk.h".

I don't get it, but I'd like to use eclipse to devlop in C/C++ because
of positive Java experiences.

Do you have any ideas, most tutorials on the topic are outdated and
the old CDT is quite different, especially regarding the project
types.

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