Import of the watch repository from Pebble

third_party/nanopb/tests/stackusage/stackusage.c

@@ -0,0 +1,94 @@
+#include <pb_encode.h>
+#include <pb_decode.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include "stackusage.pb.h"
+
+static uint8_t g_msgbuf[256];
+static size_t g_msglen;
+
+/* This is a hacky way to measure actual stack usage of functions.
+ * It works by copying the stack to a global variable, and then
+ * finding the lowest location that has been modified.
+ * Currently this assumes that the platform uses a descending stack.
+ */
+#define MAX_STACK_ENTRIES 1024
+static uint32_t g_stackbuf[MAX_STACK_ENTRIES];
+static volatile uint32_t *g_stackptr;
+
+void start_stack_measuring()
+{
+    uint32_t i = 0;
+    g_stackptr = (volatile uint32_t*)((uintptr_t)&i - MAX_STACK_ENTRIES * sizeof(uint32_t));
+    for (i = 0; i < MAX_STACK_ENTRIES; i++)
+    {
+        g_stackbuf[i] = g_stackptr[i];
+    }
+}
+
+int end_stack_measuring()
+{
+    uint32_t i = 0;
+    for (i = 0; i < MAX_STACK_ENTRIES; i++)
+    {
+        if (g_stackbuf[i] != g_stackptr[i])
+        {
+            return (MAX_STACK_ENTRIES - i) * sizeof(uint32_t);
+        }
+    }
+    assert(false);
+    return 0;
+}
+
+void do_encode()
+{
+    pb_ostream_t stream = pb_ostream_from_buffer(g_msgbuf, sizeof(g_msgbuf));
+    SettingsGroup msg = SettingsGroup_init_zero;
+    bool status;
+
+    msg.has_settings = true;
+    msg.settings.id = 1;
+    strcpy(msg.settings.name, "abcd");
+    msg.settings.en = true;
+    msg.settings.has_begin = true;
+    msg.settings.begin.label = 1234;
+    msg.settings.begin.properties_count = 1;
+    msg.settings.begin.properties[0].which_field = Property_DeviceA_Mode_tag;
+    msg.settings.begin.properties[0].field.DeviceA_Mode = 2;
+
+    status = pb_encode(&stream, SettingsGroup_fields, &msg);
+    g_msglen = stream.bytes_written;
+    assert(status);
+    assert(g_msglen > 10);
+}
+
+void do_decode()
+{
+    pb_istream_t stream = pb_istream_from_buffer(g_msgbuf, g_msglen);
+    SettingsGroup msg = SettingsGroup_init_zero;
+    bool status;
+
+    status = pb_decode(&stream, SettingsGroup_fields, &msg);
+    assert(status);
+    assert(msg.settings.begin.properties[0].field.DeviceA_Mode == 2);
+}
+
+int main()
+{
+    int stack_encode, stack_decode;
+
+    start_stack_measuring();
+    do_encode();
+    stack_encode = end_stack_measuring();
+
+    start_stack_measuring();
+    do_decode();
+    stack_decode = end_stack_measuring();
+
+    /* Print machine-readable to stdout and user-readable to stderr */
+    printf("%d %d\n", stack_encode, stack_decode);
+    fprintf(stderr, "Stack usage: encode %d bytes, decode %d bytes\n",
+            stack_encode, stack_decode);
+    return 0;
+}