Re: [Qemu-devel] [PATCH v3 2/5] add qemu_fopen_err

[Luiz Capitulino]

On Sun, 18 Mar 2012 19:29:10 +0100
Alon Levy <address@hidden> wrote:

> This adds a helper to conveniently set the correct error based on the
> errno after a failed fopen.
> 
> The added function is placed in it's own c file to allow libcacard to
> not develop dependencies on everything that qerror will bring in, which
> includes monitor and half of qemu. I tried to make it as less ugly as I
> could, by naming an osdep-no-qerror-obj-y and having that included in
> osdep-obj-y, and using only the former for libcacard.

I'm not sure I like this, how will libcacard report errors then?

> 
> Signed-off-by: Alon Levy <address@hidden>
> ---
>  Makefile.objs      |    8 +++++---
>  libcacard/Makefile |    2 +-
>  osdep-qerror.c     |   52 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  osdep-qerror.h     |    8 ++++++++
>  osdep.c            |    1 -
>  5 files changed, 66 insertions(+), 5 deletions(-)
>  create mode 100644 osdep-qerror.c
>  create mode 100644 osdep-qerror.h
> 
> diff --git a/Makefile.objs b/Makefile.objs
> index 226b01d..fb5a73a 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -20,9 +20,11 @@ universal-obj-y += $(qom-obj-y)
>  
>  #######################################################################
>  # oslib-obj-y is code depending on the OS (win32 vs posix)
> -oslib-obj-y = osdep.o
> -oslib-obj-$(CONFIG_WIN32) += oslib-win32.o qemu-thread-win32.o
> -oslib-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o
> +oslib-no-qerror-obj-y = osdep.o
> +oslib-no-qerror-obj-$(CONFIG_WIN32) += oslib-win32.o qemu-thread-win32.o
> +oslib-no-qerror-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o
> +oslib-obj-y = $(oslib-no-qerror-obj-y)
> +oslib-obj-y += osdep-qerror.o
>  
>  #######################################################################
>  # coroutines
> diff --git a/libcacard/Makefile b/libcacard/Makefile
> index c6a896a..83f483f 100644
> --- a/libcacard/Makefile
> +++ b/libcacard/Makefile
> @@ -8,7 +8,7 @@ libcacard_includedir=$(includedir)/cacard
>  $(call set-vpath, $(SRC_PATH):$(libcacard_srcpath))
>  
>  # objects linked against normal qemu binaries, not compiled with libtool
> -QEMU_OBJS=$(addprefix ../,$(oslib-obj-y) qemu-timer-common.o $(trace-obj-y))
> +QEMU_OBJS=$(addprefix ../,$(oslib-no-qerror-obj-y) qemu-timer-common.o 
> $(trace-obj-y))
>  
>  # objects linked into a shared library, built with libtool with -fPIC if 
> required
>  QEMU_OBJS_LIB=$(addsuffix .lo,$(basename $(QEMU_OBJS)))
> diff --git a/osdep-qerror.c b/osdep-qerror.c
> new file mode 100644
> index 0000000..6dac984
> --- /dev/null
> +++ b/osdep-qerror.c
> @@ -0,0 +1,52 @@
> +#include "qerror.h"
> +
> +#include "osdep-qerror.h"
> +
> +/*
> + * Helper to set an Error after a failed fopen.
> + *
> + * Uses errno so it must not be changed by another intermediate call.
> + */
> +void qemu_fopen_err(Error **errp, const char *file_name)
> +{
> +    const char *fmt = NULL;

Where's the fopen() call and the mode argument?

> +
> +    switch (errno) {
> +    case EACCES:
> +        fmt = QERR_EACCES;
> +        break;
> +    case EINTR:
> +        fmt = QERR_EINTR;
> +        break;
> +    case EEXIST:
> +        fmt = QERR_EEXIST;
> +        break;
> +    case EMFILE:
> +        fmt = QERR_OPEN_FILE_EMFILE;
> +        break;
> +    case ENOSPC:
> +        fmt = QERR_ENOSPC;
> +        break;
> +    case EPERM:
> +        fmt = QERR_EPERM;
> +        break;
> +    case EROFS:
> +        fmt = QERR_READ_ONLY;
> +        break;
> +    case ENOTDIR:
> +        fmt = QERR_ENOTDIR;
> +        break;
> +    case EFBIG:
> +        fmt = QERR_EFBIG;
> +        break;
> +    default:
> +        /*
> +         * EINVAL and ENOTSUP will result in the default
> +         *
> +         * ENOENT too, it's used by (for instance) bdrv_create_file for
> +         * a different purpose then open (2) so just give a generic error.
> +         */
> +        fmt = QERR_OPEN_FILE_FAILED;
> +    }
> +    error_set(errp, fmt, file_name);
> +}
> diff --git a/osdep-qerror.h b/osdep-qerror.h
> new file mode 100644
> index 0000000..7320f4a
> --- /dev/null
> +++ b/osdep-qerror.h
> @@ -0,0 +1,8 @@
> +#ifndef OSDEP_QERROR_H
> +#define OSDEP_QERROR_H
> +
> +#include "error.h"
> +
> +void qemu_fopen_err(Error **errp, const char *file_name);
> +
> +#endif
> diff --git a/osdep.c b/osdep.c
> index 3e6bada..efdd21c 100644
> --- a/osdep.c
> +++ b/osdep.c
> @@ -241,4 +241,3 @@ ssize_t qemu_recv_full(int fd, void *buf, size_t count, 
> int flags)
>  
>      return total;
>  }
> -