[systemd-commits] src/resolve src/shared src/test

[David Herrmann]

 src/resolve/resolved-dns-stream.c |    2 +-
 src/resolve/resolved-manager.c    |    2 +-
 src/shared/macro.h                |    3 +++
 src/test/test-util.c              |    4 ++++
 4 files changed, 9 insertions(+), 2 deletions(-)

New commits:
commit 40a1eebde6be7ac3f1885147fc24e06ad1da260c
Author: David Herrmann <dh.herrmann at gmail.com>
Date:   Fri Aug 22 13:55:57 2014 +0200

    shared: add MAXSIZE() and use it in resolved
    
    The MAXSIZE() macro takes two types and returns the size of the larger
    one. It is much simpler to use than MAX(sizeof(A), sizeof(B)) and also
    avoids any compiler-extensions, unlike CONST_MAX() and MAX() (which are
    needed to avoid evaluating arguments more than once). This was suggested
    by Daniele Nicolodi <daniele at grinta.net>.
    
    Also make resolved use this macro instead of CONST_MAX(). This enhances
    readability quite a bit.

diff --git a/src/resolve/resolved-dns-stream.c b/src/resolve/resolved-dns-stream.c
index 8b3a3ce..8aad5e4 100644
--- a/src/resolve/resolved-dns-stream.c
+++ b/src/resolve/resolved-dns-stream.c
@@ -64,7 +64,7 @@ static int dns_stream_complete(DnsStream *s, int error) {
 static int dns_stream_identify(DnsStream *s) {
         union {
                 struct cmsghdr header; /* For alignment */
-                uint8_t buffer[CMSG_SPACE(CONST_MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo)))
+                uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
                                + EXTRA_CMSG_SPACE /* kernel appears to require extra space */];
         } control;
         struct msghdr mh = {};
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index 56baf87..659b1da 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -841,7 +841,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
         union {
                 struct cmsghdr header; /* For alignment */
-                uint8_t buffer[CMSG_SPACE(CONST_MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo)))
+                uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
                                + CMSG_SPACE(int) /* ttl/hoplimit */
                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
         } control;
diff --git a/src/shared/macro.h b/src/shared/macro.h
index 179b24c..43fa3e5 100644
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -149,6 +149,9 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
                 ((_A) > (_B)) ? (_A) : (_B),                            \
                 (void)0))
 
+/* takes two types and returns the size of the larger one */
+#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
+
 #define MAX3(x,y,z)                                     \
         __extension__ ({                                \
                         const typeof(x) _c = MAX(x,y);  \
diff --git a/src/test/test-util.c b/src/test/test-util.c
index ac1afce..34d5f2e 100644
--- a/src/test/test-util.c
+++ b/src/test/test-util.c
@@ -90,6 +90,10 @@ static void test_max(void) {
         assert_se(val1.a == 100);
         assert_se(MAX(++d, 0) == 1);
         assert_se(d == 1);
+
+        assert_cc(MAXSIZE(char[3], uint16_t) == 3);
+        assert_cc(MAXSIZE(char[3], uint32_t) == 4);
+        assert_cc(MAXSIZE(char, long) == sizeof(long));
 }
 
 static void test_first_word(void) {