Add coverage

tools/telemetry/third_party/coverage/coverage/ctracer/datastack.c

Index: tools/telemetry/third_party/coverage/coverage/ctracer/datastack.c
diff --git a/tools/telemetry/third_party/coverage/coverage/ctracer/datastack.c b/tools/telemetry/third_party/coverage/coverage/ctracer/datastack.c
new file mode 100644
index 0000000000000000000000000000000000000000..1d925ad78d6a029d9cee6ebc278a9e173248eb0b
--- /dev/null
+++ b/tools/telemetry/third_party/coverage/coverage/ctracer/datastack.c
@@ -0,0 +1,42 @@
+/* Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 */
+/* For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt */
+
+#include "util.h"
+#include "datastack.h"
+
+#define STACK_DELTA    100
+
+int
+DataStack_init(Stats *pstats, DataStack *pdata_stack)
+{
+    pdata_stack->depth = -1;
+    pdata_stack->stack = NULL;
+    pdata_stack->alloc = 0;
+    return RET_OK;
+}
+
+void
+DataStack_dealloc(Stats *pstats, DataStack *pdata_stack)
+{
+    PyMem_Free(pdata_stack->stack);
+}
+
+int
+DataStack_grow(Stats *pstats, DataStack *pdata_stack)
+{
+    pdata_stack->depth++;
+    if (pdata_stack->depth >= pdata_stack->alloc) {
+        STATS( pstats->stack_reallocs++; )
+        /* We've outgrown our data_stack array: make it bigger. */
+        int bigger = pdata_stack->alloc + STACK_DELTA;
+        DataStackEntry * bigger_data_stack = PyMem_Realloc(pdata_stack->stack, bigger * sizeof(DataStackEntry));
+        if (bigger_data_stack == NULL) {
+            PyErr_NoMemory();
+            pdata_stack->depth--;
+            return RET_ERROR;
+        }
+        pdata_stack->stack = bigger_data_stack;
+        pdata_stack->alloc = bigger;
+    }
+    return RET_OK;
+}