I print out the output of C preprocessor by using
gcc -E a.c
The output contains many lines like
# 1 "a.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "a.c"
# 1 "c:\\mingw\\bin\\../lib/gcc/mingw32/4.5.0/../../../../include/stdio.h" 1 3
# 19 "c:\\mingw\\bin\\../lib/gcc/mingw32/4.5.0/../../../../include/stdio.h" 3
# 1 "c:\\mingw\\bin\\../lib/gcc/mingw32/4.5.0/../../../../include/_mingw.h" 1 3
# 31 "c:\\mingw\\bin\\../lib/gcc/mingw32/4.5.0/../../../../include/_mingw.h" 3
# 32 "c:\\mingw\\bin\\../lib/gcc/mingw32/4.5.0/../../../../include/_mingw.h" 3
# 20 "c:\\mingw\\bin\\../lib/gcc/mingw32/4.5.0/../../../../include/stdio.h" 2 3
I've never seen this kind of syntax in C. Can someone explain what this is doing?
Best Answer
These lines are hints for debugging (where the code following the line actually came from)
Meaning of flags (space separated):