From 8d8527de32065d7a3168bfbdf58e394b7022fc54 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 20 Aug 2012 13:05:31 -0600 Subject: [PATCH] build: silence stupid gcc warning on STREQ_NULLABLE Our existing STRNEQ_NULLABLE() triggered a warning in gcc 4.7 when used with a literal NULL argument: qemumonitorjsontest.c: In function 'testQemuMonitorJSONGetMachines': qemumonitorjsontest.c:289:5: error: null argument where non-null required (argument 1) [-Werror=nonnull] even though the strcmp is provably dead when a null argument is present. Squelch the warning by refactoring things so that gcc never sees strcmp() called with NULL arguments (we still compare NULL as not equal to "", this rewrite merely aids gcc). Next, gcc has a valid warning about a literal NULLSTR(NULL): qemumonitorjsontest.c:289:5: error: invalid application of 'sizeof' to a void type [-Werror=pointer-arith] Of course, you'd never write NULLSTR(NULL) directly, but it is handy to use through macros. But the entire part about verify_true() is unnecessary - gcc already warns about type mismatch with ?:, without needing to make it more complex. * src/internal.h (STREQ_NULLABLE, STRNEQ_NULLABLE): Avoid gcc 4.7 stupidity. (NULLSTR): Simplify, to allow passing compile-time constants. --- src/internal.h | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/src/internal.h b/src/internal.h index 300de3ac5c..832a9318cd 100644 --- a/src/internal.h +++ b/src/internal.h @@ -79,10 +79,9 @@ # define STRSKIP(a,b) (STRPREFIX(a,b) ? (a) + strlen(b) : NULL) # define STREQ_NULLABLE(a, b) \ - ((!(a) && !(b)) || ((a) && (b) && STREQ((a), (b)))) + ((a) ? (b) && STREQ((a) ? (a) : "", (b) ? (b) : "") : !(b)) # define STRNEQ_NULLABLE(a, b) \ - ((!(a) ^ !(b)) || ((a) && (b) && STRNEQ((a), (b)))) - + ((a) ? !(b) || STRNEQ((a) ? (a) : "", (b) ? (b) : "") : !!(b)) # define NUL_TERMINATE(buf) do { (buf)[sizeof(buf)-1] = '\0'; } while (0) # define ARRAY_CARDINALITY(Array) (sizeof(Array) / sizeof(*(Array))) @@ -206,9 +205,7 @@ /* * Use this when passing possibly-NULL strings to printf-a-likes. */ -# define NULLSTR(s) \ - ((void)verify_true(sizeof(*(s)) == sizeof(char)), \ - (s) ? (s) : "(null)") +# define NULLSTR(s) ((s) ? (s) : "(null)") /** * TODO: -- GitLab