Using this option I receive files after preprocessing. There are many lines like:
# 91 "/usr/include/stdint.h" 3 4
What do the numbers mean? First I thought that #91
is the number of line where file is included, but that is not it. And about 3 4
I have no idea at all.
According to the official documentation, the line is of the format:
# linenum filename flags
The linenum
specifies that the following line originated in filename
at that line number. Then there are four flags:
1
- Start of a new file2
- Returning to a file3
- System header file4
- Treat as being wrapped in extern "C"
So let's interpret your linemarker:
# 91 "/usr/include/stdint.h" 3 4
The following line originated from line 91 of /usr/include/stdint.h
. It is a system header file and should be treated as wrapped in extern "C"
.