[GSOC 2014][PATCH 7/7] JSON: Add support for '+++' signals

[Zhu YangMin]

There are only 3 kind of '+++' signals in strace.
Note: Currently do NOT support the '<unfinished...>/<resumed>' in
JSON format. And this will make the those JSON lines invalid(or you can
just ignore these lines). Need to find a way to solve this problem.

* process.c(sys_exit): slightly reformat the code.
* syscall.c(trace_syscall_exiting): slightly reformat the code.
* strace.c(printleader, trace):
Add support for 'superseded', 'killed' and 'exited' signals.
---
 process.c |  2 +-
 strace.c  | 26 ++++++++++++++++++++++----
 syscall.c |  5 ++---
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/process.c b/process.c
index 93678ad..8b4b1b8 100644
--- a/process.c
+++ b/process.c
@@ -261,7 +261,7 @@ sys_exit(struct tcb *tcp)
 	tprintf("%ld) ", tcp->u_arg[0]);
 	tabto();
 	tprintf("= %s\n", "?");
-	json_event(JSON_ARG, JSON_ARGS_END, JSON_SEPA, JSON_RET, JSON_CALL_END ,JSON_NEWLINE);
+	json_event(JSON_ARG, JSON_ARGS_END, JSON_SEPA, JSON_RET, JSON_CALL_END, JSON_NEWLINE);
 	line_ended();
 	return 0;
 }
diff --git a/strace.c b/strace.c
index deb636b..b973823 100644
--- a/strace.c
+++ b/strace.c
@@ -627,6 +627,7 @@ printleader(struct tcb *tcp)
 			 * didn't finish ("SIGKILL nuked us after syscall entry" etc).
 			 */
 			tprints(" <unfinished ...>\n");
+			json_event(JSON_NEWLINE);
 			printing_tcp->curcol = 0;
 		}
 	}
@@ -2249,7 +2250,12 @@ trace(void)
 			tcp->pid = pid;
 			if (cflag != CFLAG_ONLY_STATS) {
 				printleader(tcp);
-				tprintf("+++ superseded by execve in pid %lu +++\n", old_pid);
+				tprintf("+++ %s %s %lu +++\n", "superseded", "by execve in pid", old_pid);
+				json_event(
+						JSON_SIGNAL_BEGIN, JSON_SEPA,
+						JSON_DESC, JSON_SEPA,
+						JSON_AUXSTR, JSON_SEPA,
+						JSON_SIGCODE, JSON_SIGNAL_END, JSON_NEWLINE);
 				line_ended();
 				tcp->flags |= TCB_REPRINT;
 			}
@@ -2278,12 +2284,23 @@ trace(void)
 			) {
 				printleader(tcp);
 #ifdef WCOREDUMP
-				tprintf("+++ killed by %s %s+++\n",
+				tprintf("+++ %s by %s %s+++\n",
+					"killed",
 					signame(WTERMSIG(status)),
 					WCOREDUMP(status) ? "(core dumped) " : "");
+				json_event(
+						JSON_SIGNAL_BEGIN, JSON_SEPA,
+						JSON_DESC, JSON_SEPA,
+						JSON_AUXSTR, JSON_SEPA,
+						JSON_SIGCODE, JSON_SIGNAL_END, JSON_NEWLINE);
 #else
-				tprintf("+++ killed by %s +++\n",
+				tprintf("+++ %s by %s +++\n",
+					"killed",
 					signame(WTERMSIG(status)));
+				json_event(
+						JSON_SIGNAL_BEGIN, JSON_SEPA,
+						JSON_DESC, JSON_SEPA,
+						JSON_SIGCODE, JSON_SIGNAL_END, JSON_NEWLINE);
 #endif
 				line_ended();
 			}
@@ -2296,7 +2313,8 @@ trace(void)
 			if (cflag != CFLAG_ONLY_STATS &&
 			    qflag < 2) {
 				printleader(tcp);
-				tprintf("+++ exited with %d +++\n", WEXITSTATUS(status));
+				tprintf("+++ %s with %d +++\n", "exited", WEXITSTATUS(status));
+				json_event(JSON_SIGNAL_BEGIN, JSON_SEPA, JSON_DESC, JSON_SEPA, JSON_SIGCODE, JSON_SIGNAL_END, JSON_NEWLINE);
 				line_ended();
 			}
 			droptcb(tcp);
diff --git a/syscall.c b/syscall.c
index 19e0b6e..ff951e6 100644
--- a/syscall.c
+++ b/syscall.c
@@ -2580,8 +2580,7 @@ trace_syscall_exiting(struct tcb *tcp)
 		tprintf(") = %s <%s>\n", "?", "unavailable");
 		json_event(JSON_ARGS_END, JSON_SEPA,
 					  JSON_RET, JSON_SEPA,
-					  JSON_DESC,
-					  JSON_CALL_END , JSON_NEWLINE);
+					  JSON_DESC, JSON_CALL_END, JSON_NEWLINE);
 		tabto();
 		line_ended();
 		tcp->flags &= ~TCB_INSYSCALL;
@@ -2754,7 +2753,7 @@ trace_syscall_exiting(struct tcb *tcp)
 			(long) tv.tv_sec, (long) tv.tv_usec);
 	}
 	tprints("\n");
-	json_event(JSON_CALL_END , JSON_NEWLINE);
+	json_event(JSON_CALL_END, JSON_NEWLINE);
 	dumpio(tcp);
 	line_ended();
 
-- 
1.9.1