[dpdk-dev] [PATCH v7 12/25] pci: avoid over-complicated macro

Gaetan Rivet gaetan.rivet at 6wind.com
Thu Oct 26 00:38:34 CEST 2017


Using a macro helps writing the code to the detriment of the reader
in this case. This is backward. Write once, read many.

The few LOCs gained is not worth the opacity of the implementation.

Signed-off-by: Gaetan Rivet <gaetan.rivet at 6wind.com>
---
 lib/librte_eal/common/eal_common_pci.c | 67 +++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 21 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
index b4e35d0..20ae349 100644
--- a/lib/librte_eal/common/eal_common_pci.c
+++ b/lib/librte_eal/common/eal_common_pci.c
@@ -87,42 +87,67 @@ static struct rte_devargs *pci_devargs_lookup(struct rte_pci_device *dev)
 	return NULL;
 }
 
-/* Macro used by pci addr parsing functions. **/
-#define GET_PCIADDR_FIELD(in, fd, lim, dlm)                     \
-do {                                                            \
-	unsigned long val;                                      \
-	char *end;                                              \
-	errno = 0;                                              \
-	val = strtoul((in), &end, 16);                          \
-	if (errno != 0 || end[0] != (dlm) || val > (lim))       \
-		return -EINVAL;                                 \
-	(fd) = (typeof (fd))val;                                \
-	(in) = end + 1;                                         \
-} while(0)
+static inline const char *
+get_u8_pciaddr_field(const char *in, void *_u8, char dlm)
+{
+	unsigned long val;
+	uint8_t *u8 = _u8;
+	char *end;
+
+	errno = 0;
+	val = strtoul(in, &end, 16);
+	if (errno != 0 || end[0] != dlm || val > UINT8_MAX) {
+		errno = errno ? errno : EINVAL;
+		return NULL;
+	}
+	*u8 = (uint8_t)val;
+	return end + 1;
+}
 
 
 int
 eal_parse_pci_BDF(const char *input, struct rte_pci_addr *dev_addr)
 {
+	const char *in = input;
+
 	dev_addr->domain = 0;
-	GET_PCIADDR_FIELD(input, dev_addr->bus, UINT8_MAX, ':');
-	GET_PCIADDR_FIELD(input, dev_addr->devid, UINT8_MAX, '.');
-	GET_PCIADDR_FIELD(input, dev_addr->function, UINT8_MAX, 0);
+	in = get_u8_pciaddr_field(in, &dev_addr->bus, ':');
+	if (in == NULL)
+		return -EINVAL;
+	in = get_u8_pciaddr_field(in, &dev_addr->devid, '.');
+	if (in == NULL)
+		return -EINVAL;
+	in = get_u8_pciaddr_field(in, &dev_addr->function, '\0');
+	if (in == NULL)
+		return -EINVAL;
 	return 0;
 }
 
 int
 eal_parse_pci_DomBDF(const char *input, struct rte_pci_addr *dev_addr)
 {
-	GET_PCIADDR_FIELD(input, dev_addr->domain, UINT16_MAX, ':');
-	GET_PCIADDR_FIELD(input, dev_addr->bus, UINT8_MAX, ':');
-	GET_PCIADDR_FIELD(input, dev_addr->devid, UINT8_MAX, '.');
-	GET_PCIADDR_FIELD(input, dev_addr->function, UINT8_MAX, 0);
+	const char *in = input;
+	unsigned long val;
+	char *end;
+
+	errno = 0;
+	val = strtoul(in, &end, 16);
+	if (errno != 0 || end[0] != ':' || val > UINT16_MAX)
+		return -EINVAL;
+	dev_addr->domain = (uint16_t)val;
+	in = end + 1;
+	in = get_u8_pciaddr_field(in, &dev_addr->bus, ':');
+	if (in == NULL)
+		return -EINVAL;
+	in = get_u8_pciaddr_field(in, &dev_addr->devid, '.');
+	if (in == NULL)
+		return -EINVAL;
+	in = get_u8_pciaddr_field(in, &dev_addr->function, '\0');
+	if (in == NULL)
+		return -EINVAL;
 	return 0;
 }
 
-#undef GET_PCIADDR_FIELD
-
 void
 rte_pci_device_name(const struct rte_pci_addr *addr,
 		     char *output, size_t size)
-- 
2.1.4



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