trace-cmd: Correct cpu list parsing

Old parsing code is incorrect, when we execute
./trace-cmd report --cpu 1,2-4,6,9-13

the result of filter_cpus will be:
1,2,1,2,3,4,6,9,5,6,7,8,9,10,11,12,13

The correct filter_cpus should be:
1,2,3,4,6,9,10,11,12,13,

I could change about 10 existing lines to make it correct, but the result
would still be poorly readable, so I ported the neat and nicely readable code:
linux_kernel_src/lib/bitmap.c:bitmap_parselist()
to here and replaced the origin code.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D78A0A6.2060009@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 19 insertions, 57 deletions

diff --git a/trace-read.c b/trace-read.c
index 1cd9bd3..932f5aa 100644
--- a/trace-read.c
+++ b/trace-read.c
@@ -738,9 +738,8 @@ static void sig_end(int sig)
         exit(0);
 }
 
-static const char *inc_and_test_char(const char *p, const char *cpu_str)
+static const char *skip_space_and_test_digit(const char *p, const char *cpu_str)
 {
-        p++;
         while (isspace(*p))
                 p++;
         if (!isdigit(*p))
@@ -754,64 +753,27 @@ static void __add_cpu(int cpu)
         filter_cpus = tracecmd_add_id(filter_cpus, cpu, nr_filter_cpus++);
 }
 
-static int process_cpu_str(const char *cpu_str)
+static void parse_cpulist(const char *cpu_str)
 {
-        const char *p = cpu_str;
-        int cpu, ncpu, ret_cpu = 1;
+        unsigned a, b;
+        const char *s = cpu_str;
 
         do {
-                while (isspace(*p))
-                        p++;
-
-                cpu = atoi(p);
-                __add_cpu(cpu);
-
- again:
-                while (isdigit(*p))
-                        p++;
-                while (isspace(*p))
-                        p++;
-
-                if (*p) {
-                        ret_cpu = 0;
-                        switch (*p) {
-                        case '-':
-                                p = inc_and_test_char(p, cpu_str);
-                                ncpu = atoi(p);
-                                if (ncpu < cpu)
-                                        die("range of cpu numbers must be lower to greater");
-                                for (; cpu <= ncpu; cpu++)
-                                        __add_cpu(cpu);
-                                break;
-
-                        case ',':
-                        case ':':
-                                p = inc_and_test_char(p, cpu_str);
-                                ncpu = atoi(p);
-                                __add_cpu(ncpu);
-                                break;
-                        default:
-                                die("invalid character '%c' in cpu string '%s'",
-                                    *p, cpu_str);
-                        }
-                        goto again;
+                s = skip_space_and_test_digit(s, cpu_str);
+                b = a = strtoul(s, (char **)&s, 10);
+                if (*s == '-') {
+                        s = skip_space_and_test_digit(s + 1, cpu_str);
+                        b = strtoul(s, (char **)&s, 10);
                 }
-        } while (*p);
-
-        if (ret_cpu)
-                return cpu;
-
-        /* Return -1 if we added more than one CPU */
-        return -1;
-}
-
-static void add_cpu(const char *cpu_str)
-{
-        int cpu;
-
-        cpu = process_cpu_str(cpu_str);
-        if (cpu >= 0)
-                __add_cpu(cpu);
+                if (!(a <= b))
+                        die("range of cpu numbers must be lower to greater");
+                while (a <= b) {
+                        __add_cpu(a);
+                        a++;
+                }
+                if (*s == ',' || *s == ':')
+                        s++;
+        } while (*s != '\0');
 }
 
 static void read_file_fd(int fd, char *dst, int len)
@@ -958,7 +920,7 @@ void trace_report (int argc, char **argv)
                 case 0:
                         switch(option_index) {
                         case 0: /* cpu */
-                                add_cpu(optarg);
+                                parse_cpulist(optarg);
                                 break;
                         case 1: /* events */
                                 print_events = 1;