From 8f6421179ad29cbdaa9d5c5b39e9c001996c0f07 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 5 Sep 2011 16:31:45 +0100 Subject: [PATCH] trace: allow trace events with string arguments String arguments are useful for producing human-readable traces without post-processing (e.g. stderr backend). Although the simple backend cannot handles strings all others can. Strings should be allowed and the simple backend can be extended to support them. Signed-off-by: Stefan Hajnoczi --- docs/tracing.txt | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/docs/tracing.txt b/docs/tracing.txt index d0171aabda..2c33a62b98 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -70,11 +70,6 @@ Trace events should use types as follows: cannot include all user-defined struct declarations and it is therefore necessary to use void * for pointers to structs. - Pointers (including char *) cannot be dereferenced easily (or at all) in - some trace backends. If pointers are used, ensure they are meaningful by - themselves and do not assume the data they point to will be traced. Do - not pass in string arguments. - * For everything else, use primitive scalar types (char, int, long) with the appropriate signedness. @@ -182,6 +177,9 @@ source tree. It may not be as powerful as platform-specific or third-party trace backends but it is portable. This is the recommended trace backend unless you have specific needs for more advanced backends. +The "simple" backend currently does not capture string arguments, it simply +records the char* pointer value instead of the string that is pointed to. + ==== Monitor commands ==== * info trace -- 2.11.4.GIT