https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70518
--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- On Sun, 3 Apr 2016, elyk03 at gmail dot com wrote: > Should #line be processed unconditionally? I know the preprocessor has to > keep It should not be processed in skipped blocks. See C11 6.10.1#6: "Each directive’s condition is checked in order. If it evaluates to false (zero), the group that it controls is skipped: directives are processed only through the name that determines the directive in order to keep track of the level of nested conditionals; the rest of the directives’ preprocessing tokens are ignored, as are the other preprocessing tokens in the group.". This means, for example, that #if 0 #line invalid line directive #endif is valid, whereas that #line directive would not be valid outside #if 0.
