Re: [Qemu-devel] [PATCH] qemu-char: Use g_new() & friends where that makes obvious sense

[Paolo Bonzini <pbonzini@redhat.com>]

On 14/09/2015 13:54, Markus Armbruster wrote:
> g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
> for two reasons.  One, it catches multiplication overflowing size_t.
> Two, it returns T * rather than void *, which lets the compiler catch
> more type errors.
> 
> This commit only touches allocations with size arguments of the form
> sizeof(T).  Same Coccinelle semantic patchas in commit b45c03f.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  backends/testdev.c |  4 ++--
>  qemu-char.c        | 22 +++++++++++-----------
>  2 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/backends/testdev.c b/backends/testdev.c
> index eba396a..1429152 100644
> --- a/backends/testdev.c
> +++ b/backends/testdev.c
> @@ -113,8 +113,8 @@ CharDriverState *chr_testdev_init(void)
>      TestdevCharState *testdev;
>      CharDriverState *chr;
>  
> -    testdev = g_malloc0(sizeof(TestdevCharState));
> -    testdev->chr = chr = g_malloc0(sizeof(CharDriverState));
> +    testdev = g_new0(TestdevCharState, 1);
> +    testdev->chr = chr = g_new0(CharDriverState, 1);
>  
>      chr->opaque = testdev;
>      chr->chr_write = testdev_write;
> diff --git a/qemu-char.c b/qemu-char.c
> index dd83203..653ea10 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -685,7 +685,7 @@ static CharDriverState *qemu_chr_open_mux(CharDriverState *drv)
>      MuxDriver *d;
>  
>      chr = qemu_chr_alloc();
> -    d = g_malloc0(sizeof(MuxDriver));
> +    d = g_new0(MuxDriver, 1);
>  
>      chr->opaque = d;
>      d->drv = drv;
> @@ -1064,7 +1064,7 @@ static CharDriverState *qemu_chr_open_fd(int fd_in, int fd_out)
>      FDCharDriver *s;
>  
>      chr = qemu_chr_alloc();
> -    s = g_malloc0(sizeof(FDCharDriver));
> +    s = g_new0(FDCharDriver, 1);
>      s->fd_in = io_channel_from_fd(fd_in);
>      s->fd_out = io_channel_from_fd(fd_out);
>      qemu_set_nonblock(fd_out);
> @@ -1413,7 +1413,7 @@ static CharDriverState *qemu_chr_open_pty(const char *id,
>      fprintf(stderr, "char device redirected to %s (label %s)\n",
>              pty_name, id);
>  
> -    s = g_malloc0(sizeof(PtyCharDriver));
> +    s = g_new0(PtyCharDriver, 1);
>      chr->opaque = s;
>      chr->chr_write = pty_chr_write;
>      chr->chr_update_read_handler = pty_chr_update_read_handler;
> @@ -1762,7 +1762,7 @@ static CharDriverState *qemu_chr_open_pp_fd(int fd)
>          return NULL;
>      }
>  
> -    drv = g_malloc0(sizeof(ParallelCharDriver));
> +    drv = g_new0(ParallelCharDriver, 1);
>      drv->fd = fd;
>      drv->mode = IEEE1284_MODE_COMPAT;
>  
> @@ -2050,7 +2050,7 @@ static CharDriverState *qemu_chr_open_win_path(const char *filename)
>      WinCharState *s;
>  
>      chr = qemu_chr_alloc();
> -    s = g_malloc0(sizeof(WinCharState));
> +    s = g_new0(WinCharState, 1);
>      chr->opaque = s;
>      chr->chr_write = win_chr_write;
>      chr->chr_close = win_chr_close;
> @@ -2149,7 +2149,7 @@ static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts)
>      WinCharState *s;
>  
>      chr = qemu_chr_alloc();
> -    s = g_malloc0(sizeof(WinCharState));
> +    s = g_new0(WinCharState, 1);
>      chr->opaque = s;
>      chr->chr_write = win_chr_write;
>      chr->chr_close = win_chr_close;
> @@ -2168,7 +2168,7 @@ static CharDriverState *qemu_chr_open_win_file(HANDLE fd_out)
>      WinCharState *s;
>  
>      chr = qemu_chr_alloc();
> -    s = g_malloc0(sizeof(WinCharState));
> +    s = g_new0(WinCharState, 1);
>      s->hcom = fd_out;
>      chr->opaque = s;
>      chr->chr_write = win_chr_write;
> @@ -2324,7 +2324,7 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
>      int                is_console = 0;
>  
>      chr   = qemu_chr_alloc();
> -    stdio = g_malloc0(sizeof(WinStdioCharState));
> +    stdio = g_new0(WinStdioCharState, 1);
>  
>      stdio->hStdIn = GetStdHandle(STD_INPUT_HANDLE);
>      if (stdio->hStdIn == INVALID_HANDLE_VALUE) {
> @@ -2487,7 +2487,7 @@ static CharDriverState *qemu_chr_open_udp_fd(int fd)
>      NetCharDriver *s = NULL;
>  
>      chr = qemu_chr_alloc();
> -    s = g_malloc0(sizeof(NetCharDriver));
> +    s = g_new0(NetCharDriver, 1);
>  
>      s->fd = fd;
>      s->chan = io_channel_from_socket(s->fd);
> @@ -2713,7 +2713,7 @@ static int tcp_set_msgfds(CharDriverState *chr, int *fds, int num)
>      g_free(s->write_msgfds);
>  
>      if (num) {
> -        s->write_msgfds = g_malloc(num * sizeof(int));
> +        s->write_msgfds = g_new(int, num);
>          memcpy(s->write_msgfds, fds, num * sizeof(int));
>      }
>  
> @@ -4144,7 +4144,7 @@ static CharDriverState *qmp_chardev_open_socket(ChardevSocket *sock,
>      int64_t reconnect   = sock->has_reconnect ? sock->reconnect : 0;
>  
>      chr = qemu_chr_alloc();
> -    s = g_malloc0(sizeof(TCPCharDriver));
> +    s = g_new0(TCPCharDriver, 1);
>  
>      s->fd = -1;
>      s->listen_fd = -1;
> 

Thanks, applied locally (pull request will come later this week).

Paolo