diff options
Diffstat (limited to 'gcc/cppfiles.c')
| -rw-r--r-- | gcc/cppfiles.c | 140 |
1 files changed, 113 insertions, 27 deletions
diff --git a/gcc/cppfiles.c b/gcc/cppfiles.c index 395976f..2955902 100644 --- a/gcc/cppfiles.c +++ b/gcc/cppfiles.c @@ -28,6 +28,17 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "intl.h" #include "mkdeps.h" +#ifdef HAVE_MMAP_FILE +# include <sys/mman.h> +# ifndef MMAP_THRESHOLD +# define MMAP_THRESHOLD 3 /* Minimum page count to mmap the file. */ +# endif + +#else /* No MMAP_FILE */ +# undef MMAP_THRESHOLD +# define MMAP_THRESHOLD 0 +#endif + static IHASH *redundant_include_p PARAMS ((cpp_reader *, IHASH *, struct file_name_list *)); static IHASH *make_IHASH PARAMS ((const char *, const char *, @@ -45,8 +56,10 @@ static int eq_IHASH PARAMS ((const void *, const void *)); static int find_include_file PARAMS ((cpp_reader *, const char *, struct file_name_list *, IHASH **, int *)); -static int read_include_file PARAMS ((cpp_reader *, int, IHASH *)); static inline int open_include_file PARAMS ((cpp_reader *, const char *)); +static int read_include_file PARAMS ((cpp_reader *, int, IHASH *)); +static ssize_t read_with_read PARAMS ((cpp_buffer *, int, ssize_t)); +static ssize_t read_file PARAMS ((cpp_buffer *, int, ssize_t)); #if 0 static void hack_vms_include_specification PARAMS ((char *)); @@ -678,8 +691,7 @@ read_include_file (pfile, fd, ihash) IHASH *ihash; { struct stat st; - size_t st_size; - long length; + ssize_t length; cpp_buffer *fp; fp = cpp_push_buffer (pfile, NULL, 0); @@ -690,35 +702,37 @@ read_include_file (pfile, fd, ihash) if (fstat (fd, &st) < 0) goto perror_fail; - /* If fd points to a plain file, we know how big it is, so we can - allocate the buffer all at once. If fd is a pipe or terminal, we - can't. Most C source files are 4k or less, so we guess that. If - fd is something weird, like a directory, we don't want to read it - at all. + /* If fd points to a plain file, we might be able to mmap it; we can + definitely allocate the buffer all at once. If fd is a pipe or + terminal, we can't do either. If fd is something weird, like a + block device or a directory, we don't want to read it at all. Unfortunately, different systems use different st.st_mode values for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and zero the entire struct stat except a couple fields. Hence we don't even try to figure out what something is, except for plain files, - directories, and block devices. - - In all cases, read_and_prescan will resize the buffer if it - turns out there's more data than we thought. */ + directories, and block devices. */ if (S_ISREG (st.st_mode)) { - /* off_t might have a wider range than size_t - in other words, + ssize_t st_size; + + /* off_t might have a wider range than ssize_t - in other words, the max size of a file might be bigger than the address space. We can't handle a file that large. (Anyone with - a single source file bigger than 4GB needs to rethink + a single source file bigger than 2GB needs to rethink their coding style.) */ - st_size = (size_t) st.st_size; - if ((unsigned HOST_WIDEST_INT) st_size - != (unsigned HOST_WIDEST_INT) st.st_size) + if (st.st_size > SSIZE_MAX) { - cpp_error (pfile, "file `%s' is too large", ihash->name); + cpp_error (pfile, "%s is too large", ihash->name); goto fail; } + st_size = st.st_size; + length = read_file (fp, fd, st_size); + if (length == -1) + goto perror_fail; + if (length < st_size) + cpp_warning (pfile, "%s is shorter than expected\n", ihash->name); } else if (S_ISBLK (st.st_mode)) { @@ -732,25 +746,28 @@ read_include_file (pfile, fd, ihash) } else { - /* We don't know how big this is. 4k is a decent first guess. */ - st_size = 4096; + /* 8 kilobytes is a sensible starting size. It ought to be + bigger than the kernel pipe buffer, and it's definitely + bigger than the majority of C source files. */ + length = read_with_read (fp, fd, 8 * 1024); + if (length == -1) + goto perror_fail; } - /* Read the file, converting end-of-line characters and trigraphs - (if enabled). */ + /* These must be set before prescan. */ fp->ihash = ihash; fp->nominal_fname = ihash->name; - length = _cpp_read_and_prescan (pfile, fp, fd, st_size); - if (length < 0) - goto fail; + if (length == 0) ihash->control_macro = U""; /* never re-include */ + else + /* Temporary - I hope. */ + length = _cpp_prescan (pfile, fp, length); - close (fd); fp->rlimit = fp->buf + length; fp->cur = fp->buf; if (ihash->foundhere != ABSOLUTE_PATH) - fp->system_header_p = ihash->foundhere->sysp; + fp->system_header_p = ihash->foundhere->sysp; fp->lineno = 1; fp->line_base = fp->buf; @@ -761,6 +778,7 @@ read_include_file (pfile, fd, ihash) pfile->input_stack_listing_current = 0; pfile->only_seen_white = 2; + close (fd); return 1; perror_fail: @@ -772,6 +790,74 @@ read_include_file (pfile, fd, ihash) return 0; } +static ssize_t +read_file (fp, fd, size) + cpp_buffer *fp; + int fd; + ssize_t size; +{ + static int pagesize = -1; + + if (size == 0) + return 0; + + if (pagesize == -1) + pagesize = getpagesize (); + +#if MMAP_THRESHOLD + if (size / pagesize >= MMAP_THRESHOLD) + { + const U_CHAR *result + = (const U_CHAR *) mmap (0, size, PROT_READ, MAP_PRIVATE, fd, 0); + if (result != (const U_CHAR *)-1) + { + fp->buf = result; + fp->mapped = 1; + return size; + } + } + /* If mmap fails, try read. If there's really a problem, read will + fail too. */ +#endif + + return read_with_read (fp, fd, size); +} + +static ssize_t +read_with_read (fp, fd, size) + cpp_buffer *fp; + int fd; + ssize_t size; +{ + ssize_t offset, count; + U_CHAR *buf; + + buf = (U_CHAR *) xmalloc (size); + offset = 0; + while ((count = read (fd, buf + offset, size - offset)) > 0) + { + offset += count; + if (offset == size) + buf = xrealloc (buf, (size *= 2)); + } + if (count < 0) + { + free (buf); + return -1; + } + if (offset == 0) + { + free (buf); + return 0; + } + + if (offset < size) + buf = xrealloc (buf, offset); + fp->buf = buf; + fp->mapped = 0; + return offset; +} + /* Given a path FNAME, extract the directory component and place it onto the actual_dirs list. Return a pointer to the allocated file_name_list structure. These structures are used to implement |