From 1e9b65bb1bad51735cab6c861c29b592dccabf0e Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 19 Jun 2015 19:21:59 +0200 Subject: error: On abort, report where the error was created This is particularly useful when we abort in error_propagate(), because there the stack backtrace doesn't lead to where the error was created. Looks like this: Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322: qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action Aborted (core dumped) Note: to get this example output, I monkey-patched drive_new() to pass &error_abort to blockdev_init(). To keep the error handling boiler plate from growing even more, all error_setFOO() become macros expanding into error_setFOO_internal() with additional __FILE__, __LINE__, __func__ arguments. Not exactly pretty, but it works. The macro trickery breaks down when you take the address of an error_setFOO(). Fortunately, we do that in just one place: qemu-ga's Windows VSS provider and requester DLL wants to call error_setg_win32() through a function pointer "to avoid linking glib to the DLL". Use error_setg_win32_internal() there. The use of the function pointer is already wrapped in a macro, so the churn isn't bad. Code size increases by some 35KiB for me (0.7%). Tolerable. Could be less if we passed relative rather than absolute source file names to the compiler, or forwent reporting __func__. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Acked-by: Laszlo Ersek --- util/error.c | 55 +++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 39 insertions(+), 16 deletions(-) (limited to 'util') diff --git a/util/error.c b/util/error.c index b842f2040c..cdb726ce81 100644 --- a/util/error.c +++ b/util/error.c @@ -18,12 +18,23 @@ struct Error { char *msg; ErrorClass err_class; + const char *src, *func; + int line; }; Error *error_abort; -static void error_setv(Error **errp, ErrorClass err_class, - const char *fmt, va_list ap) +static void error_do_abort(Error *err) +{ + fprintf(stderr, "Unexpected error in %s() at %s:%d:\n", + err->func, err->src, err->line); + error_report_err(err); + abort(); +} + +static void error_setv(Error **errp, + const char *src, int line, const char *func, + ErrorClass err_class, const char *fmt, va_list ap) { Error *err; int saved_errno = errno; @@ -36,10 +47,12 @@ static void error_setv(Error **errp, ErrorClass err_class, err = g_malloc0(sizeof(*err)); err->msg = g_strdup_vprintf(fmt, ap); err->err_class = err_class; + err->src = src; + err->line = line; + err->func = func; if (errp == &error_abort) { - error_report_err(err); - abort(); + error_do_abort(err); } *errp = err; @@ -47,25 +60,31 @@ static void error_setv(Error **errp, ErrorClass err_class, errno = saved_errno; } -void error_set(Error **errp, ErrorClass err_class, const char *fmt, ...) +void error_set_internal(Error **errp, + const char *src, int line, const char *func, + ErrorClass err_class, const char *fmt, ...) { va_list ap; va_start(ap, fmt); - error_setv(errp, err_class, fmt, ap); + error_setv(errp, src, line, func, err_class, fmt, ap); va_end(ap); } -void error_setg(Error **errp, const char *fmt, ...) +void error_setg_internal(Error **errp, + const char *src, int line, const char *func, + const char *fmt, ...) { va_list ap; va_start(ap, fmt); - error_setv(errp, ERROR_CLASS_GENERIC_ERROR, fmt, ap); + error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR, fmt, ap); va_end(ap); } -void error_setg_errno(Error **errp, int os_errno, const char *fmt, ...) +void error_setg_errno_internal(Error **errp, + const char *src, int line, const char *func, + int os_errno, const char *fmt, ...) { va_list ap; char *msg; @@ -76,7 +95,7 @@ void error_setg_errno(Error **errp, int os_errno, const char *fmt, ...) } va_start(ap, fmt); - error_setv(errp, ERROR_CLASS_GENERIC_ERROR, fmt, ap); + error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR, fmt, ap); va_end(ap); if (os_errno != 0) { @@ -88,14 +107,19 @@ void error_setg_errno(Error **errp, int os_errno, const char *fmt, ...) errno = saved_errno; } -void error_setg_file_open(Error **errp, int os_errno, const char *filename) +void error_setg_file_open_internal(Error **errp, + const char *src, int line, const char *func, + int os_errno, const char *filename) { - error_setg_errno(errp, os_errno, "Could not open '%s'", filename); + error_setg_errno_internal(errp, src, line, func, os_errno, + "Could not open '%s'", filename); } #ifdef _WIN32 -void error_setg_win32(Error **errp, int win32_err, const char *fmt, ...) +void error_setg_win32_internal(Error **errp, + const char *src, int line, const char *func, + int win32_err, const char *fmt, ...) { va_list ap; char *msg1, *msg2; @@ -105,7 +129,7 @@ void error_setg_win32(Error **errp, int win32_err, const char *fmt, ...) } va_start(ap, fmt); - error_setv(errp, ERROR_CLASS_GENERIC_ERROR, fmt, ap); + error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR, fmt, ap); va_end(ap); if (win32_err != 0) { @@ -158,8 +182,7 @@ void error_free(Error *err) void error_propagate(Error **dst_errp, Error *local_err) { if (local_err && dst_errp == &error_abort) { - error_report_err(local_err); - abort(); + error_do_abort(local_err); } else if (dst_errp && !*dst_errp) { *dst_errp = local_err; } else if (local_err) { -- cgit v1.2.1