PostgreSQL, OpenSSL, and the GPL

But that is part of the code that libssl may compile into your program. Glibc will compile similar chunks into your code; see bits/stdlib.h. Or libpng/png.h where png_composite is a small chunk of inline code. There's enough of these files to say that to exclude these from being "ordinary" header files, /usr/include has an awful lot of header files that are or include superordinary files.