uio: fix compilation with -Og

The compilation with gcc-6.3.0 and EXTRA_CFLAGS=-Og gives the following
error:

  CC eal_pci_uio.o
  eal_pci_uio.c: In function ‘pci_get_uio_de ’:
  eal_pci_uio.c:221:9: error: ‘uio_num’ may be used uninitialized in
                       this function [-Werror=maybe-uninitialized]
  return uio_num;
         ^~~~~~~

This is a false positive: gcc is not able to see that when e != NULL,
uio_num is always set. Fix the warning by initializing uio_num to -1,
and by the way, change the type to int.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
index fa10329..b639ab9 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
@@ -154,7 +154,7 @@ pci_get_uio_dev(struct rte_pci_device *dev, char *dstbuf,
                           unsigned int buflen, int create)
 {
        struct rte_pci_addr *loc = &dev->addr;
-       unsigned int uio_num;
+       int uio_num = -1;
        struct dirent *e;
        DIR *dir;
        char dirname[PATH_MAX];