🚀 go-pugleaf

Hi there,

can anybody explain to me the semantics of the text generated by the GCC
preprocessor? Especially the entering and leaving of files raises some
questions since the output of GCC when processing some Objective-C source
file is in contradiction with my original understanding of the semantics.

I thought that a '1' after the filename means that the preprocessor enterred
that file and a '2' means the preprocessor left the file. However, in the
output generated by the preprocessor the following occurs (my apologies for
the lines that are too long):

# 1 "/depot/objc/src/runtime/Object.h" 1
# 1 "/depot/objc/src/runtime/objc.h" 1
# 1 "/depot/gnuStuff/solaris/lib/gcc-lib/sparc-sun-solaris2.3/2.7.2/include/stdio.h" 1 3
# 1 "/usr/include/sys/feature_tests.h" 1 3
# 17 "/depot/gnuStuff/solaris/lib/gcc-lib/sparc-sun-solaris2.3/2.7.2/include/stdio.h" 2 3
# 194 "/depot/gnuStuff/solaris/lib/gcc-lib/sparc-sun-solaris2.3/2.7.2/include/stdio.h" 3
# 268 "/depot/gnuStuff/solaris/lib/gcc-lib/sparc-sun-solaris2.3/2.7.2/include/stdio.h" 3
# 16 "/depot/objc/src/runtime/objc.h" 2
# 1 "/depot/objc/src/runtime/host.h" 1
# 94 "/depot/objc/src/runtime/host.h"
# 115 "/depot/objc/src/runtime/host.h"
# 69 "/depot/objc/src/runtime/objc.h" 2
# 1 "/depot/objc/src/runtime/101fname.h" 1
# 48 "/depot/objc/src/runtime/101fname.h"
# 70 "/depot/objc/src/runtime/objc.h" 2

As you can see, three (in my opinion) strange things happen:

1) The file stdio.h is left BEFORE feature_tests.h which was enterred via
   stdio.h and should therefore be left prior to stdio.h. The same happens
   with host.h and 101fname.h in combination with objc.h.

2) After the preprocessor has left the file stdio.h, it claims that it is
   still in stdio.h (with line number 194 and 268 resp.).

3) The file objc.h is left THREE times, even though it is enterred only once.

Can somebody shed a light on this please?

Thanks in advance,

regards, Patrick.