From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Fri, 2 Feb 2018 13:34:00 +0000 (+0100)
Subject: basic/hashmap: tweak code to avoid pointless gcc warning
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=1dd825d80c669db0f5c84470621b99d8da156d65;p=elogind.git

basic/hashmap: tweak code to avoid pointless gcc warning

gcc says:
[196/1142] Compiling C object 'src/basic/basic@sta/hashmap.c.o'.
../src/basic/hashmap.c: In function ‘cachemem_maintain’:
../src/basic/hashmap.c:1913:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
                 mem->active = r = true;
                 ^~~

which conflates two things: the first is transitive assignent a = b = c = d;
the second is assignment of the value of an expression, which happens to be a
an assignment expression here, and boolean. While the second _should_ be
parenthesized, the first should _not_, and it's more natural to understand
our code as the first, and gcc should treat this as an exception and not emit
the warning. But since it's a while until this will be fixed, let's update
our code too.
---

diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c
index 876a10eeb..03ed3b8df 100644
--- a/src/basic/hashmap.c
+++ b/src/basic/hashmap.c
@@ -1904,8 +1904,6 @@ int set_put_strsplit(Set *s, const char *v, const char *separators, ExtractFlags
 
 /* expand the cachemem if needed, return true if newly (re)activated. */
 static int cachemem_maintain(CacheMem *mem, unsigned size) {
-        int r = false;
-
         assert(mem);
 
         if (!GREEDY_REALLOC(mem->ptr, mem->n_allocated, size)) {
@@ -1913,10 +1911,12 @@ static int cachemem_maintain(CacheMem *mem, unsigned size) {
                         return -ENOMEM;
         }
 
-        if (!mem->active)
-                mem->active = r = true;
+        if (!mem->active) {
+                mem->active = true;
+                return true;
+        }
 
-        return r;
+        return false;
 }
 
 int iterated_cache_get(IteratedCache *cache, const void ***res_keys, const void ***res_values, unsigned *res_n_entries) {