From: Ivan Boule <ivan.boule@6wind.com>
Date: Thu, 22 Sep 2011 16:01:35 +0000 (+0200)
Subject: app: fix volatile read for GCC >= 4.6
X-Git-Tag: spdx-start~11275
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=85f5ae8b70062bef6e9289542879e007945a29f1;p=dpdk.git

app: fix volatile read for GCC >= 4.6

When a memory address must be read, for instance a [mapped] PCI register,
the read value is assigned to a local variable that is not used after,
as for instance:
    x = *((uint8_t *) mem_addr);

Such instructions do not compile with gcc 4.6.
The fix consists in adding the "volatile" attribute to the accessed data type
and to not assign the read value:
    *((volatile uint8_t *) mem_addr);

Signed-off-by: Ivan Boule <ivan.boule@6wind.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
---

diff --git a/app/test/test_memory.c b/app/test/test_memory.c
index f9c70370b5..0dd09a620f 100644
--- a/app/test/test_memory.c
+++ b/app/test/test_memory.c
@@ -60,7 +60,6 @@ test_memory(void)
 	uint64_t s;
 	unsigned i, j;
 	const struct rte_memseg *mem;
-	volatile uint8_t x;
 
 	/*
 	 * dump the mapped memory: the python-expect script checks
@@ -82,8 +81,7 @@ test_memory(void)
 
 		/* check memory */
 		for (j = 0; j<mem[i].len; j++) {
-			x = *((uint8_t *) mem[i].addr + j);
-			RTE_SET_USED(x);
+			*((volatile uint8_t *) mem[i].addr + j);
 		}
 	}