From c20f18fbe847416f89c6362aea8604b2b2e28aae Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Mon, 12 Apr 2010 17:38:17 +0100 Subject: [PATCH] libxl: Make logging functions preserve errno This is needed by the following patches. It makes it much more convenient for libxl functions to return the errno value from the failure, when they fail. Signed-off-by: Ian Jackson --- tools/libxl/libxl_internal.c | 5 ++++- tools/libxl/libxl_internal.h | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/libxl/libxl_internal.c b/tools/libxl/libxl_internal.c index f48e9eb109..4dcdabe653 100644 --- a/tools/libxl/libxl_internal.c +++ b/tools/libxl/libxl_internal.c @@ -156,11 +156,13 @@ void xl_logv(struct libxl_ctx *ctx, int loglevel, int errnoval, { char *enomem = "[out of memory formatting log message]"; char *s; - int rc; + int rc, esave; if (!ctx->log_callback) return; + esave = errno; + rc = vasprintf(&s, fmt, ap); if (rc<0) { s = enomem; goto x; } @@ -180,6 +182,7 @@ void xl_logv(struct libxl_ctx *ctx, int loglevel, int errnoval, ctx->log_callback(ctx->log_userdata, loglevel, file, line, func, s); if (s != enomem) free(s); + errno = esave; } void xl_log(struct libxl_ctx *ctx, int loglevel, int errnoval, diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index 300c108bb4..10e72e520f 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -47,6 +47,7 @@ #define XL_LOG_ERRNO(ctx, loglevel, _f, _a...) #define XL_LOG_ERRNOVAL(ctx, loglevel, errnoval, _f, _a...) #endif + /* all of these macros preserve errno (saving and restoring) */ #define XL_LOG_DEBUG 3 #define XL_LOG_INFO 2 @@ -56,6 +57,7 @@ /* logging */ void xl_logv(struct libxl_ctx *ctx, int errnoval, int loglevel, const char *file, int line, const char *func, char *fmt, va_list al); void xl_log(struct libxl_ctx *ctx, int errnoval, int loglevel, const char *file, int line, const char *func, char *fmt, ...); + /* these functions preserve errno (saving and restoring) */ typedef enum { -- 2.30.2