[PATCH 1/2] perf tools: Concatenate strings in expressions

[PATCH 1/2] perf tools: Concatenate strings in expressions

[Jörg Sommer]

The tracepoint event kvm_userspace_exit uses string snippet the C
compiler concatenates to a big string, e.g. "KVM_EXIT_" "UNKNOWN". The
parser of the data must do the same and join successive strings.

print fmt: "reason %s (%d)", … __print_symbolic(REC->reason, { 0, "KVM_EXIT_" "UNKNOWN" }, { 1, "KVM_EXIT_" "EXCEPTION" } …

Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de>
---
 tools/perf/util/trace-event-parse.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 1a8d4dc..185e284 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -1726,6 +1726,21 @@ process_arg_token(struct event *event, struct print_arg *arg,
 		}
 		break;
 	case EVENT_DQUOTE:
+		atom = token;
+		type = read_token_item(&token);
+
+		/* merge with following strings */
+		while (type == EVENT_DQUOTE) {
+			atom = realloc(atom, strlen(atom) + strlen(token) + 1);
+			strcat(atom, token);
+			free_token(token);
+			type = read_token_item(&token);
+		}
+
+		arg->type = PRINT_ATOM;
+		arg->atom.atom = atom;
+
+		break;
 	case EVENT_SQUOTE:
 		arg->type = PRINT_ATOM;
 		arg->atom.atom = token;
-- 
1.7.9.1

[PATCH 2/2] perf tools: Fix parsing of unary operator in ?: expression

[Jörg Sommer]

Parsing an expression like

print fmt: "reason %s (%d)", …, REC->errno < 0 ? -REC->errno : REC->reason

in kvm_space_exit fails with

Fatal unknown op ':'

The colon after a simple operator signals the end of this expression. The
token should not be advanced, because the colon is handled in
process_cond(). Hence, it's enough to signal there's an operation
heading.

Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de>
---
An alternative could be:

 --- a/tools/perf/util/trace-event-parse.c
 +++ b/tools/perf/util/trace-event-parse.c
 @@ -1287,7 +1287,7 @@ process_op(struct event *event, struct print_arg *arg, char **tok)
                return EVENT_NONE;
        }
 
-       if (type == EVENT_OP) {
+       if (type == EVENT_OP && strcmp(*tok, ":") != 0) {
                int prio;
 
                /* higher prios need to be closer to the root */


 tools/perf/util/trace-event-parse.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 185e284..d7b5880 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -1125,6 +1125,7 @@ static int get_op_prio(char *op)
 		case '|':
 			return 13;
 		case '?':
+		case ':':
 			return 16;
 		default:
 			die("unknown op '%c'", op[0]);
@@ -1202,6 +1203,8 @@ process_op(struct event *event, struct print_arg *arg, char **tok)
 
 		type = process_arg(event, right, tok);
 
+	} else if (strcmp(token, ":") == 0) {
+		return EVENT_OP;
 	} else if (strcmp(token, "?") == 0) {
 
 		left = malloc_or_die(sizeof(*left));
-- 
1.7.9.1

Re: [PATCH 2/2] perf tools: Fix parsing of unary operator in ?: expression

[Arnaldo Carvalho de Melo]

Em Sun, Mar 25, 2012 at 11:11:32PM +0200, Jörg Sommer escreveu:
> Parsing an expression like
> 
> print fmt: "reason %s (%d)", …, REC->errno < 0 ? -REC->errno : REC->reason
> 
> in kvm_space_exit fails with

There is no 'kvm_space_exit' I could google for except in this patch,
this is 'kvm_userspace_exit', right?

Fixing that in the changeset log.

- Arnaldo
 
> Fatal unknown op ':'
> 
> The colon after a simple operator signals the end of this expression. The
> token should not be advanced, because the colon is handled in
> process_cond(). Hence, it's enough to signal there's an operation
> heading.
> 
> Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de>
> ---
> An alternative could be:
> 
>  --- a/tools/perf/util/trace-event-parse.c
>  +++ b/tools/perf/util/trace-event-parse.c
>  @@ -1287,7 +1287,7 @@ process_op(struct event *event, struct print_arg *arg, char **tok)
>                 return EVENT_NONE;
>         }
>  
> -       if (type == EVENT_OP) {
> +       if (type == EVENT_OP && strcmp(*tok, ":") != 0) {
>                 int prio;
>  
>                 /* higher prios need to be closer to the root */
> 
> 
>  tools/perf/util/trace-event-parse.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
> index 185e284..d7b5880 100644
> --- a/tools/perf/util/trace-event-parse.c
> +++ b/tools/perf/util/trace-event-parse.c
> @@ -1125,6 +1125,7 @@ static int get_op_prio(char *op)
>  		case '|':
>  			return 13;
>  		case '?':
> +		case ':':
>  			return 16;
>  		default:
>  			die("unknown op '%c'", op[0]);
> @@ -1202,6 +1203,8 @@ process_op(struct event *event, struct print_arg *arg, char **tok)
>  
>  		type = process_arg(event, right, tok);
>  
> +	} else if (strcmp(token, ":") == 0) {
> +		return EVENT_OP;
>  	} else if (strcmp(token, "?") == 0) {
>  
>  		left = malloc_or_die(sizeof(*left));
> -- 
> 1.7.9.1

Re: [PATCH 1/2] perf tools: Concatenate strings in expressions

[Arnaldo Carvalho de Melo]

Em Sun, Mar 25, 2012 at 11:08:39PM +0200, Jörg Sommer escreveu:
> The tracepoint event kvm_userspace_exit uses string snippet the C
> compiler concatenates to a big string, e.g. "KVM_EXIT_" "UNKNOWN". The
> parser of the data must do the same and join successive strings.
> 
> print fmt: "reason %s (%d)", … __print_symbolic(REC->reason, { 0, "KVM_EXIT_" "UNKNOWN" }, { 1, "KVM_EXIT_" "EXCEPTION" } …
> 
> Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de>
> ---
>  tools/perf/util/trace-event-parse.c |   15 +++++++++++++++
>  1 files changed, 15 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
> index 1a8d4dc..185e284 100644
> --- a/tools/perf/util/trace-event-parse.c
> +++ b/tools/perf/util/trace-event-parse.c
> @@ -1726,6 +1726,21 @@ process_arg_token(struct event *event, struct print_arg *arg,
>  		}
>  		break;
>  	case EVENT_DQUOTE:
> +		atom = token;
> +		type = read_token_item(&token);
> +
> +		/* merge with following strings */
> +		while (type == EVENT_DQUOTE) {
> +			atom = realloc(atom, strlen(atom) + strlen(token) + 1);

realloc can fail, please check its result and take appropriate action.

- Arnaldo

> +			strcat(atom, token);
> +			free_token(token);
> +			type = read_token_item(&token);
> +		}
> +
> +		arg->type = PRINT_ATOM;
> +		arg->atom.atom = atom;
> +
> +		break;
>  	case EVENT_SQUOTE:
>  		arg->type = PRINT_ATOM;
>  		arg->atom.atom = token;
> -- 
> 1.7.9.1