This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [PATCH v3] Allow using special files with File I/O functions
Le 29/06/2018 à 15:42, Pedro Alves a écrit :
On 06/28/2018 08:27 PM, Julio Guerra wrote:
- Remove the restriction to regular files only and add support for special file
types in the File IO stat structure.
- Define a few more macro definitions of file types such as FIFOs, etc.
The major goal is being able to write advanced embedded testing functions, like:
- using a FIFO between the embedded program and the host, instead of being
restricted only to the GDB console.
- mocking features based on host's by opening some /dev special files.
This needs a GDB manual change, and a NEWS entry.
Ok.
2018-06-28 Julio Guerra <julio@farjump.io>
* remote-fileio.c (remote_fileio_func_open, remote_fileio_func_stat):
Allow using File I/O functions open(), stat() and fstat() on special
files.
* ../include/gdb/fileio.h: Add macro definitions for special files,
both for fst_dev and fst_mode fields of struct fst_stat.
* common/fileio.c (fileio_to_host_mode, fileio_mode_pack): Add new
special file types in fst_mode's definition.
(host_to_fileio_stat): Define fst_dev using the new macro definitions
and according to the file's type.
Note that include/ has its own ChangeLog file.
Ok.
2018-06-27 Simon Marchi <simon.marchi@ericsson.com>
* gdb-gdb.py.in (StructMainTypePrettyPrinter) <to_string>: Don't
diff --git a/gdb/common/fileio.c b/gdb/common/fileio.c
index 912a7ede3c..9ee78e227c 100644
--- a/gdb/common/fileio.c
+++ b/gdb/common/fileio.c
@@ -119,12 +119,31 @@ fileio_to_host_mode (int fileio_mode, mode_t *mode_p)
if (fileio_mode & ~FILEIO_S_SUPPORTED)
return -1;
- if (fileio_mode & FILEIO_S_IFREG)
- mode |= S_IFREG;
- if (fileio_mode & FILEIO_S_IFDIR)
- mode |= S_IFDIR;
- if (fileio_mode & FILEIO_S_IFCHR)
- mode |= S_IFCHR;
+ switch (fileio_mode & FILEIO_S_IFMT)
+ {
+ case FILEIO_S_IFSOCK:
+ *mode_p |= S_IFSOCK;
+ break;
+ case FILEIO_S_IFLNK:
+ mode |= S_IFLNK;
+ break;
+ case FILEIO_S_IFREG:
+ mode |= S_IFREG;
+ break;
+ case FILEIO_S_IFBLK:
+ mode |= S_IFBLK;
+ break;
+ case FILEIO_S_IFDIR:
+ mode |= S_IFDIR;
+ break;
+ case FILEIO_S_IFCHR:
+ mode |= S_IFCHR;
+ break;
+ case FILEIO_S_IFIFO:
+ mode |= S_IFIFO;
+ break;
+ }
+
if (fileio_mode & FILEIO_S_IRUSR)
mode |= S_IRUSR;
if (fileio_mode & FILEIO_S_IWUSR)
@@ -165,12 +184,31 @@ fileio_mode_pack (mode_t mode)
{
mode_t tmode = 0;
- if (S_ISREG (mode))
- tmode |= FILEIO_S_IFREG;
- if (S_ISDIR (mode))
- tmode |= FILEIO_S_IFDIR;
- if (S_ISCHR (mode))
- tmode |= FILEIO_S_IFCHR;
+ switch (mode & S_IFMT)
+ {
+ case S_IFSOCK:
+ tmode |= FILEIO_S_IFSOCK;
+ break;
+ case S_IFLNK:
+ tmode |= FILEIO_S_IFLNK;
+ break;
+ case S_IFREG:
+ tmode |= FILEIO_S_IFREG;
+ break;
+ case S_IFBLK:
+ tmode |= FILEIO_S_IFBLK;
+ break;
+ case S_IFDIR:
+ tmode |= FILEIO_S_IFDIR;
+ break;
+ case S_IFCHR:
+ tmode |= FILEIO_S_IFCHR;
+ break;
+ case S_IFIFO:
+ tmode |= FILEIO_S_IFIFO;
+ break;
+ }
I'm not sure whether all these S_FOO macros exist
on all hosts.
Looking at:
https://www.gnu.org/software/gnulib/manual/html_node/sys_002fstat_002eh.html
gnulib's sys/stat.h (gdb/gnulib/import/sys_stat.in.h) adds some
replacements, but then I'm not sure whether checking S_IFxxx
etc. directly instead of using the S_ISxxx function-style macros
is the right thing to do portability-wise. It may be S_ISxxx was being
used for a reason?
I assumed a system >= POSIX.1-2001 here. man 7 inode says:
The S_IF* constants are present in POSIX.1-2001 and later.
[…]
The S_ISLNK() and S_ISSOCK() macros were not in POSIX.1-1996, but
both are present in POSIX.1-2001
+
if (mode & S_IRUSR)
tmode |= FILEIO_S_IRUSR;
if (mode & S_IWUSR)
@@ -224,8 +262,10 @@ void
host_to_fileio_stat (struct stat *st, struct fio_stat *fst)
{
LONGEST blksize;
+ long fst_dev;
We don't align variable names like that.
Ok.
- host_to_fileio_uint ((long) st->st_dev, fst->fst_dev);
+ fst_dev = S_ISREG(st->st_mode) ? FILEIO_STDEV_FILE : FILEIO_STDEV_SPECIAL;
Missing space in "S_ISREG (".
Ok.
+ host_to_fileio_uint (fst_dev, fst->fst_dev);
host_to_fileio_uint ((long) st->st_ino, fst->fst_ino);
host_to_fileio_mode (st->st_mode, fst->fst_mode);
host_to_fileio_uint ((long) st->st_nlink, fst->fst_nlink);
diff --git a/gdb/remote-fileio.c b/gdb/remote-fileio.c
index 313da642ea..837081269a 100644
--- a/gdb/remote-fileio.c
+++ b/gdb/remote-fileio.c
@@ -407,24 +407,6 @@ remote_fileio_func_open (remote_target *remote, char *buf)
return;
}
- /* Check if pathname exists and is not a regular file or directory. If so,
- return an appropriate error code. Same for trying to open directories
- for writing. */
Did you intend to remove the "Same for trying to open directories
for writing." part?
Yes, because of man 2 open:
EISDIR: The named file is a directory and oflag includes O_WRONLY or O_RDWR,
or includes O_CREAT without O_DIRECTORY.
I wait for your comments until I resubmit a v4.
Thank you,
--
Julio Guerra