cpplib: Only push buffers if necessary
Neil Booth
neil@daikokuya.demon.co.uk
Tue Aug 21 10:49:00 GMT 2001
We currently push a zero-length buffer if there is an error opening a
file, or if we re-include a guarded header.
This was to avoid some kind of segfault with the old code if we didn't
push a buffer I think, but with the rearrangement of -include and
-imacros handling I did yesterday there doesn't seem to be any reason
to waste time pushing and popping nothing.
So this patch has the relevant functions return a boolean indicating
whether a buffer was in fact pushed. I've tried to get it to segfault
without succeeding.
The patch includes the previous systemheaderness diff.
Bootstrapping x86 Linux, will commit on completion.
Neil.
* cppfiles.c (stack_include_file): Harmonize system headerness tests.
* cppfiles.c (stack_include_file): Only stack a file if there
is something to do. Return a boolean indicating whether a
buffer was stacked or not.
(_cpp_execute_include): Similarly.
(_cpp_read_file): Similarly.
* cpphash.h (_cpp_read_file, _cpp_execute_include): Update prototypes.
Index: cppfiles.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cppfiles.c,v
retrieving revision 1.125
diff -u -p -r1.125 cppfiles.c
--- cppfiles.c 2001/08/17 22:23:47 1.125
+++ cppfiles.c 2001/08/21 17:35:08
@@ -95,7 +95,7 @@ static struct include_file *
enum include_type));
static struct include_file *open_file PARAMS ((cpp_reader *, const char *));
static int read_include_file PARAMS ((cpp_reader *, struct include_file *));
-static void stack_include_file PARAMS ((cpp_reader *, struct include_file *));
+static bool stack_include_file PARAMS ((cpp_reader *, struct include_file *));
static void purge_cache PARAMS ((struct include_file *));
static void destroy_node PARAMS ((splay_tree_value));
static int report_missing_guard PARAMS ((splay_tree_node, void *));
@@ -275,59 +275,59 @@ open_file (pfile, filename)
return 0;
}
-/* Place the file referenced by INC into a new buffer on PFILE's
- stack. If there are errors, or the file should not be re-included,
- a null (zero-length) buffer is pushed. */
+/* Place the file referenced by INC into a new buffer on the buffer
+ stack, unless there are errors, or the file is not re-included
+ because of e.g. multiple-include guards. Returns true if a buffer
+ is stacked. */
-static void
+static bool
stack_include_file (pfile, inc)
cpp_reader *pfile;
struct include_file *inc;
{
- size_t len = 0;
cpp_buffer *fp;
- int sysp, deps_sysp;
+ int sysp;
const char *filename;
+
+ if (DO_NOT_REREAD (inc))
+ return false;
- /* We'll try removing deps_sysp after the release of 3.0. */
- deps_sysp = pfile->system_include_depth != 0;
sysp = MAX ((pfile->map ? pfile->map->sysp : 0),
(inc->foundhere ? inc->foundhere->sysp : 0));
/* For -M, add the file to the dependencies on its first inclusion. */
- if (CPP_OPTION (pfile, print_deps) > deps_sysp && !inc->include_count)
+ if (CPP_OPTION (pfile, print_deps) > sysp && !inc->include_count)
deps_add_dep (pfile->deps, inc->name);
/* Not in cache? */
- if (! DO_NOT_REREAD (inc) && ! inc->buffer)
+ if (! inc->buffer)
{
/* If an error occurs, do not try to read this file again. */
if (read_include_file (pfile, inc))
- _cpp_never_reread (inc);
+ {
+ _cpp_never_reread (inc);
+ return false;
+ }
close (inc->fd);
inc->fd = -1;
}
- if (! DO_NOT_REREAD (inc))
+ if (pfile->buffer)
{
- len = inc->st.st_size;
- if (pfile->buffer)
- {
- /* We don't want MI guard advice for the main file. */
- inc->include_count++;
+ /* We don't want MI guard advice for the main file. */
+ inc->include_count++;
- /* Handle -H option. */
- if (CPP_OPTION (pfile, print_include_names))
- {
- for (fp = pfile->buffer; fp; fp = fp->prev)
- putc ('.', stderr);
- fprintf (stderr, " %s\n", inc->name);
- }
+ /* Handle -H option. */
+ if (CPP_OPTION (pfile, print_include_names))
+ {
+ for (fp = pfile->buffer; fp; fp = fp->prev)
+ putc ('.', stderr);
+ fprintf (stderr, " %s\n", inc->name);
}
}
/* Push a buffer. */
- fp = cpp_push_buffer (pfile, inc->buffer, len, BUF_FILE, 0);
+ fp = cpp_push_buffer (pfile, inc->buffer, inc->st.st_size, BUF_FILE, 0);
fp->inc = inc;
fp->inc->refcnt++;
@@ -341,6 +341,8 @@ stack_include_file (pfile, inc)
if (*filename == '\0')
filename = _("<stdin>");
_cpp_do_file_change (pfile, LC_ENTER, filename, 1, sysp);
+
+ return true;
}
/* Read the file referenced by INC into the file cache.
@@ -663,13 +665,15 @@ handle_missing_header (pfile, fname, ang
cpp_error_from_errno (pfile, fname);
}
-/* Returns non-zero if a buffer was stacked. */
-int
+/* Handles #include-family directives, and the command line -imacros
+ and -include. Returns true if a buffer was stacked. */
+bool
_cpp_execute_include (pfile, header, type)
cpp_reader *pfile;
const cpp_token *header;
enum include_type type;
{
+ bool stacked = false;
struct include_file *inc = find_include_file (pfile, header, type);
if (inc == 0)
@@ -680,15 +684,13 @@ _cpp_execute_include (pfile, header, typ
if (header->type == CPP_HEADER_NAME)
pfile->system_include_depth++;
- stack_include_file (pfile, inc);
+ stacked = stack_include_file (pfile, inc);
if (type == IT_IMPORT)
_cpp_never_reread (inc);
-
- return 1;
}
- return 0;
+ return stacked;
}
/* Locate HEADER, and determine whether it is newer than the current
@@ -714,23 +716,23 @@ _cpp_compare_file_date (pfile, header)
}
-/* Push an input buffer and load it up with the contents of FNAME.
- If FNAME is "", read standard input. */
-int
+/* Push an input buffer and load it up with the contents of FNAME. If
+ FNAME is "", read standard input. Return true if a buffer was
+ stacked. */
+bool
_cpp_read_file (pfile, fname)
cpp_reader *pfile;
const char *fname;
{
struct include_file *f = open_file (pfile, fname);
+ bool stacked = false;
if (f == NULL)
- {
- cpp_error_from_errno (pfile, fname);
- return 0;
- }
+ cpp_error_from_errno (pfile, fname);
+ else
+ stacked = stack_include_file (pfile, f);
- stack_include_file (pfile, f);
- return 1;
+ return stacked;
}
/* Do appropriate cleanup when a file buffer is popped off the input
Index: cpphash.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cpphash.h,v
retrieving revision 1.119
diff -u -p -r1.119 cpphash.h
--- cpphash.h 2001/08/21 06:20:17 1.119
+++ cpphash.h 2001/08/21 17:35:09
@@ -391,8 +391,8 @@ extern void _cpp_destroy_hashtable PARAM
extern void _cpp_fake_include PARAMS ((cpp_reader *, const char *));
extern void _cpp_never_reread PARAMS ((struct include_file *));
extern char *_cpp_simplify_pathname PARAMS ((char *));
-extern int _cpp_read_file PARAMS ((cpp_reader *, const char *));
-extern int _cpp_execute_include PARAMS ((cpp_reader *,
+extern bool _cpp_read_file PARAMS ((cpp_reader *, const char *));
+extern bool _cpp_execute_include PARAMS ((cpp_reader *,
const cpp_token *,
enum include_type));
extern int _cpp_compare_file_date PARAMS ((cpp_reader *,
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