[dpdk-dev] [PATCH 07/13] pci: avoid over-complicated macro

[Gaetan Rivet <gaetan.rivet@6wind.com>]

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@6wind.com>
---
 lib/librte_pci/rte_pci.c | 65 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 19 deletions(-)

diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c
index 8584b55..cbb5359 100644
--- a/lib/librte_pci/rte_pci.c
+++ b/lib/librte_pci/rte_pci.c
@@ -53,36 +53,63 @@
 
 #include "rte_pci.h"
 
-/* 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;
 }
 
-- 
2.1.4