Copyright (C) 2000-2012 |
GNU Info (cpp-295.info)OutputC Preprocessor Output ===================== The output from the C preprocessor looks much like the input, except that all preprocessing directive lines have been replaced with blank lines and all comments with spaces. Whitespace within a line is not altered; however, unless `-traditional' is used, spaces may be inserted into the expansions of macro calls to prevent tokens from being concatenated. Source file name and line number information is conveyed by lines of the form # LINENUM FILENAME FLAGS which are inserted as needed into the middle of the input (but never within a string or character constant). Such a line means that the following line originated in file FILENAME at line LINENUM. After the file name comes zero or more flags, which are `1', `2', `3', or `4'. If there are multiple flags, spaces separate them. Here is what the flags mean: `1' This indicates the start of a new file. `2' This indicates returning to a file (after having included another file). `3' This indicates that the following text comes from a system header file, so certain warnings should be suppressed. `4' This indicates that the following text should be treated as C. |