* cppfiles.c: Move all default-#defines to top of file.
(open_include_file): Replace by lookup_include_file.
(read_with_read, read_file): Merged into read_include_file.
(stack_include_file, purge_cache): New functions.
(close_cached_fd): Delete.
(lookup_include_file, read_include_file, _cpp_pop_file_buffer):
Cache the in-memory buffer, not the file descriptor.
* cpphash.h (struct include_file): Add buffer, st, refcnt,
mapped fields.
(xcnew): New utility macro.
(DO_NOT_REREAD, NEVER_REREAD): Move up by struct include_file.
* cpplib.h (struct cpp_buffer): Remove mapped field.
* cpplex.c (parse_string): Accept backslash space newline as a
line continuation.
(lex_line): Likewise.
(_cpp_get_token): Remove hard limit on macro nesting.
testsuite:
* gcc.dg/cpp/backslash.c: New test.
From-SVN: r36347
