--- Comment #3 from Thorsten Otto <ad...@tho-otto.de> ---
When compiling the attached source file, which includes a header file marked as
system header (same happens when include some real file from a system header
path), specifying -Wdeclaration-after-statement, no diagnostic is printed.
The reason is that the macro expansion gets in the way, resulting in a
preprocessed source of (roughly)
# 4 "bla.c"
# 8 "bla.c" 3
# 8 "bla.c"
pid = 0;
essentialy marking the remaining translation unit as system header.