Hello,
on Fedora Rawhide, gnulib compilation yields the following warning:
gcc -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -I. -Ilib -I./lib -Isrc
-I./src -O2 -flto=auto -ffat-lto-objects -fexceptions -g
-grecord-gcc-switches -pipe -Wall -Werror=format-security
-Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS
-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong
-specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mcpu=power8 -mtune=power8
-fasynchronous-unwind-tables -fstack-clash-protection -c -o lib/trim.o
lib/trim.c
make[2]: Leaving directory '/builddir/build/BUILD/datamash-1.8'
lib/trim.c: In function 'trim2':
lib/trim.c:103:16: warning: 'r' may be used uninitialized
[-Wmaybe-uninitialized]
103 | *r = '\0';
| ~~~^~~~~~
lib/trim.c:69:17: note: 'r' was declared here
69 | char *r IF_LINT (= NULL); /* used only while state = 2 */
| ^
Looking at the code [1], it seems that there was an attempt to fix this
warning in GCC or in another checker.
However, to eliminate the warning, the code also can be simplified like this:
```
diff --git a/lib/trim.c b/lib/trim.c
index 162c43e1de..bfd743cf0f 100644
--- a/lib/trim.c
+++ b/lib/trim.c
@@ -30,12 +30,6 @@
#include "mbiter.h"
#include "xalloc.h"
-/* Use this to suppress gcc's "...may be used before initialized" warnings. */
-#if defined GCC_LINT || defined lint
-# define IF_LINT(Code) Code
-#else
-# define IF_LINT(Code) /* empty */
-#endif
char *
trim2 (const char *s, int how)
@@ -66,7 +60,6 @@ trim2 (const char *s, int how)
if (how != TRIM_LEADING)
{
unsigned int state = 0;
- char *r IF_LINT (= NULL); /* used only while state = 2 */
mbi_init (i, d, strlen (d));
@@ -87,7 +80,7 @@ trim2 (const char *s, int how)
if (state == 1 && mb_isspace (mbi_cur (i)))
{
state = 2;
- r = (char *) mbi_cur_ptr (i);
+ *(char *) mbi_cur_ptr (i) = 0;
}
else if (state == 2 && mb_isspace (mbi_cur (i)))
{
@@ -98,9 +91,6 @@ trim2 (const char *s, int how)
state = 1;
}
}
-
- if (state == 2)
- *r = '\0';
}
}
else
```
In that way the warning is reliably eliminated, there is no need anymore
for clever macro tricks and arguably the code is now easier to grasp.
Best regards,
Georg
[1]:
https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/trim.c;h=162c43e1dec073db4147287d71526f2d44ee1705;hb=HEAD#l69
--
'Setting environment variables from .travis.yml
Broadcast message from root@testing-gce-259341e4-fe5b-44da-9a00-6941f50689b5
The system is going down for power off NOW!'
2016, Travis CI log of a 'failed' build
