trace-cmd: Add indentation to function tracer

Add a plugin_function.so that will override the function tracer
and use the parent functions to determine how to indent
a function. This give a nice visual affect similar to what
the function graph tracer provides.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 144 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 662a306..564af66 100644
--- a/Makefile
+++ b/Makefile
@@ -265,7 +265,7 @@ TCMD_LIB_OBJS = $(PEVENT_LIB_OBJS) trace-util.o trace-input.o trace-ftrace.o \
                         trace-output.o trace-record.o
 
 PLUGIN_OBJS = plugin_hrtimer.o plugin_kmem.o plugin_sched_switch.o \
-        plugin_mac80211.o plugin_jbd2.o
+        plugin_mac80211.o plugin_jbd2.o plugin_function.o
 
 PLUGINS := $(PLUGIN_OBJS:.o=.so)
 
diff --git a/plugin_function.c b/plugin_function.c
new file mode 100644
index 0000000..9ee0eaa
--- /dev/null
+++ b/plugin_function.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "parse-events.h"
+
+static struct func_stack {
+        int index;
+        int size;
+        char **stack;
+} *fstack;
+
+static int cpus = -1;
+
+#define STK_BLK 10
+
+static void add_child(struct func_stack *stack, const char *child, int pos)
+{
+        int i;
+
+        if (!child)
+                return;
+
+        if (pos < stack->size)
+                free(stack->stack[pos]);
+        else {
+                if (!stack->stack)
+                        stack->stack = malloc_or_die(sizeof(char *) * STK_BLK);
+                else
+                        stack->stack = realloc(stack->stack, sizeof(char *) *
+                                               (stack->size + STK_BLK));
+                for (i = stack->size; i < stack->size + STK_BLK; i++)
+                        stack->stack[i] = NULL;
+                stack->size += STK_BLK;
+        }
+
+        stack->stack[pos] = strdup(child);
+}
+
+static int get_index(const char *parent, const char *child, int cpu)
+{
+        int i;
+
+        if (cpu < 0)
+                return 0;
+
+        if (cpu > cpus) {
+                if (fstack)
+                        fstack = realloc(fstack, sizeof(*fstack) * (cpu + 1));
+                else
+                        fstack = malloc_or_die(sizeof(*fstack) * (cpu + 1));
+
+                /* Account for holes in the cpu count */
+                for (i = cpus + 1; i <= cpu; i++)
+                        memset(&fstack[i], 0, sizeof(fstack[i]));
+                cpus = cpu;
+        }
+
+        for (i = 0; i < fstack[cpu].size && fstack[cpu].stack[i]; i++) {
+                if (strcmp(parent, fstack[cpu].stack[i]) == 0) {
+                        add_child(&fstack[cpu], child, i+1);
+                        return i;
+                }
+        }
+
+        /* Not found */
+        add_child(&fstack[cpu], parent, 0);
+        add_child(&fstack[cpu], child, 1);
+        return 0;
+}
+
+static int function_handler(struct trace_seq *s, struct record *record,
+                            struct event_format *event, void *context)
+{
+        struct pevent *pevent = event->pevent;
+        unsigned long long function;
+        const char *func;
+        const char *parent;
+        int i, index;
+
+        if (pevent_get_field_val(s, event, "ip", record, &function, 1))
+                return trace_seq_putc(s, '!');
+
+        func = pevent_find_function(pevent, function);
+
+        if (pevent_get_field_val(s, event, "parent_ip", record, &function, 1))
+                return trace_seq_putc(s, '!');
+
+        parent = pevent_find_function(pevent, function);
+
+        index = get_index(parent, func, record->cpu);
+
+        for (i = 0; i < index; i++)
+                trace_seq_printf(s, "   ");
+
+        if (func)
+                trace_seq_printf(s, "%s", func);
+        else
+                trace_seq_printf(s, "0x%llx", function);
+
+        return 0;
+}
+
+int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
+{
+        pevent_register_event_handler(pevent, -1, "ftrace", "function",
+                                      function_handler, NULL);
+
+        return 0;
+}
+
+void PEVENT_PLUGIN_UNLOADER(void)
+{
+        int i, x;
+
+        for (i = 0; i <= cpus; i++) {
+                for (x = 0; x < fstack[i].size && fstack[i].stack[x]; x++)
+                        free(fstack[i].stack[x]);
+                free(fstack[i].stack);
+        }
+
+        free(fstack);
+}