Compilation error with strncpy

[iolalla]

In gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0 I had the following error while compiling:

In file included from /usr/include/string.h:519,
from /home/iolalla/src/pquery/src/third_party/inih++/lib/ini.c:12:
In function ‘strncpy’,
inlined from ‘strncpy0’ at /home/iolalla/src/pquery/src/third_party/inih++/lib/ini.c:55:3,
inlined from ‘ini_parse_file’ at /home/iolalla/src/pquery/src/third_party/inih++/lib/ini.c:143:9:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:95:10: error: ‘__builtin_strncpy’ output may be truncated copying 49 bytes from a string of length 199 [-Werror=stringop-truncation]
95 | return __builtin___strncpy_chk (__dest, __src, __len,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
96 | __glibc_objsize (__dest));
| ~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [src/third_party/inih++/lib/CMakeFiles/inih++.dir/build.make:82: src/third_party/inih++/lib/CMakeFiles/inih++.dir/ini.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:196: src/third_party/inih++/lib/CMakeFiles/inih++.dir/all] Error 2
make: *** [Makefile:171: all] Error 2

In order to fix it I changed strncpy with memcpy and compile smoothly:

diff --git a/src/third_party/inih++/lib/ini.c b/src/third_party/inih++/lib/ini.c
index 5228f0d..33d4691 100644
--- a/src/third_party/inih++/lib/ini.c
+++ b/src/third_party/inih++/lib/ini.c
@@ -52,7 +52,7 @@ static char* find_char_or_comment(const char* s, char c) {

/* Version of strncpy that ensures dest (size bytes) is null-terminated. /
static char strncpy0(char* dest, const char* src, size_t size) {

• strncpy(dest, src, size);

• memcpy(dest, src, size);
  dest[size - 1] = '\0';
  return dest;
  }

If you prefer I can do a pull request

[RoelVdP]

@mohitj1988 Hi! Can you please fix this in the repo? I think you ran into similar in pstress? Thanks

[RoelVdP]

While at it, please also have a look at #27 if it is correct, and other open tickets. Thank you.

[mohitj1988]

Hi @RoelVdP - This was fixed in pstress a while ago. The commit ID: a4fbeb3.
I will fix it in pquery as well

[RoelVdP]

Yes, I am aware. Thank you!

[RoelVdP]

Btw, I thought there was some feedback that the memcpy introduced a new bug?
See benhoyt/inih#104 (comment)