From bae41c847f084fe64b5920f09d7ffbac579c507a Mon Sep 17 00:00:00 2001
From: Craig Tiller <craig.tiller@gmail.com>
Date: Tue, 28 Apr 2015 13:22:25 -0700
Subject: [PATCH] Promote SWAP to GPR_SWAP

---
 include/grpc/support/useful.h   |  7 +++++++
 src/core/support/slice_buffer.c | 16 +++++-----------
 src/core/surface/call.c         | 11 ++---------
 3 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/include/grpc/support/useful.h b/include/grpc/support/useful.h
index 979f3d026b3..e1ce0455c6a 100644
--- a/include/grpc/support/useful.h
+++ b/include/grpc/support/useful.h
@@ -45,4 +45,11 @@
 
 #define GPR_ARRAY_SIZE(array) (sizeof(array) / sizeof(*(array)))
 
+#define GPR_SWAP(type, a, b) \
+  do {                   \
+    type x = a;          \
+    a = b;               \
+    b = x;               \
+  } while (0)
+
 #endif  /* GRPC_SUPPORT_USEFUL_H */
diff --git a/src/core/support/slice_buffer.c b/src/core/support/slice_buffer.c
index 1992eeef8b5..91b5d8c98b2 100644
--- a/src/core/support/slice_buffer.c
+++ b/src/core/support/slice_buffer.c
@@ -37,6 +37,7 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/useful.h>
 
 /* grow a buffer; requires GRPC_SLICE_BUFFER_INLINE_ELEMENTS > 1 */
 #define GROW(x) (3 * (x) / 2)
@@ -161,17 +162,10 @@ void gpr_slice_buffer_reset_and_unref(gpr_slice_buffer *sb) {
   sb->length = 0;
 }
 
-#define SWAP(type, a, b) \
-  do {                   \
-    type x = a;          \
-    a = b;               \
-    b = x;               \
-  } while (0)
-
 void gpr_slice_buffer_swap(gpr_slice_buffer *a, gpr_slice_buffer *b) {
-  SWAP(size_t, a->count, b->count);
-  SWAP(size_t, a->capacity, b->capacity);
-  SWAP(size_t, a->length, b->length);
+  GPR_SWAP(size_t, a->count, b->count);
+  GPR_SWAP(size_t, a->capacity, b->capacity);
+  GPR_SWAP(size_t, a->length, b->length);
 
   if (a->slices == a->inlined) {
     if (b->slices == b->inlined) {
@@ -193,6 +187,6 @@ void gpr_slice_buffer_swap(gpr_slice_buffer *a, gpr_slice_buffer *b) {
     memcpy(a->slices, b->inlined, a->count * sizeof(gpr_slice));
   } else {
     /* no inlining: easy swap */
-    SWAP(gpr_slice *, a->slices, b->slices);
+    GPR_SWAP(gpr_slice *, a->slices, b->slices);
   }
 }
diff --git a/src/core/surface/call.c b/src/core/surface/call.c
index f358eb546a9..d21bfaa5923 100644
--- a/src/core/surface/call.c
+++ b/src/core/surface/call.c
@@ -238,13 +238,6 @@ struct grpc_call {
 #define CALL_FROM_TOP_ELEM(top_elem) \
   CALL_FROM_CALL_STACK(grpc_call_stack_from_top_element(top_elem))
 
-#define SWAP(type, x, y) \
-  do {                   \
-    type temp = x;       \
-    x = y;               \
-    y = temp;            \
-  } while (0)
-
 static void do_nothing(void *ignored, grpc_op_error also_ignored) {}
 static void set_deadline_alarm(grpc_call *call, gpr_timespec deadline);
 static void call_on_done_recv(void *call, int success);
@@ -575,12 +568,12 @@ static void finish_live_ioreq_op(grpc_call *call, grpc_ioreq_op op,
                             call->request_data[GRPC_IOREQ_RECV_STATUS_DETAILS]);
           break;
         case GRPC_IOREQ_RECV_INITIAL_METADATA:
-          SWAP(grpc_metadata_array, call->buffered_metadata[0],
+          GPR_SWAP(grpc_metadata_array, call->buffered_metadata[0],
                *call->request_data[GRPC_IOREQ_RECV_INITIAL_METADATA]
                     .recv_metadata);
           break;
         case GRPC_IOREQ_RECV_TRAILING_METADATA:
-          SWAP(grpc_metadata_array, call->buffered_metadata[1],
+          GPR_SWAP(grpc_metadata_array, call->buffered_metadata[1],
                *call->request_data[GRPC_IOREQ_RECV_TRAILING_METADATA]
                     .recv_metadata);
           break;