GNU Global - cannot find C++ member definitions

Question

I'm using GNU Global with a C++ project in Emacs and want to find the definition of a class member starting from any use of that member within a member function.

Example for illustration:

class Foo                  // Foo.h
{
    int doSomething();
    int bar;
};

int Foo::doSomething()     // Foo.cpp
{
    return bar;
}

class Foo1                // Foo1.h 
{
    int bar(int b);
};

int Foo1::bar(int b)
{
    return b+1;
}

class Foo2                // Foo2.h
{
    int bar(int b);
};

int Foo2::bar(int b)
{
    return b+1;
}

I have set the environment variable GTAGSFORCECPP for C++ support. After running gtags (without any parameters), I want to see all definitions of the name "bar" by using global -d --result=grep bar (The -d actually doesn't make a difference). The result is

Foo1.h:6:int Foo1::bar(int b)
Foo2.h:6:int Foo2::bar(int b)

which is missing the definition of the member Foo::bar. On the other hand, if i search for references via global -r --result=grep bar, the outcome is

Foo.cpp:3:    return bar;
Foo.h:4:    int bar;
Foo1.h:3:    int bar(int b);
Foo2.h:3:    int bar(int b);

How must Global be configured so that int bar; gets classified as a definition and not as a reference?

So this is kind of the theory part. In practice, I'm using Global from within Emacs and want to find the definition of bar, when hitting M-. on return bar;. Emacs calls global -v --result=grep --color=always --path-style=shorter --from-here=3:Foo.cpp -- bar which outputs the same as global -d --result=grep bar. I have also tried different parsers (exuberant-ctags, pygments) by setting GTAGSLABEL, but that doesn't help.

score 0 · Answer 1 · answered Aug 28 '22 at 08:34

The problem can be avoided by using the plug-in parser exuberant-ctags and not setting GTAGSFORCECPP (as it is said in the manual). Then, global -d --result=grep bar contains the definition of Foo::bar :

Foo.h:4:int bar;
Foo1.h:6:int Foo1::bar(int b)
Foo2.h:6:int Foo2::bar(int b)

GNU Global - cannot find C++ member definitions

1 Answers1