https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89688
Bug ID: 89688
Summary: -Wstringop-overflow confused by 2D array of char
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redbeard0531 at gmail dot com
Target Milestone: ---
Also, for some reason it repeats the warning 3 times.
https://godbolt.org/z/SStUsl
// Fine
extern const char a[2] = {'1'};
auto z = __builtin_strlen(a);
// Warns
extern const char aa[1][2] = {{'2'}};
auto zz = __builtin_strlen(aa[0]);
> ~/opensource/gcc/prefix/bin/g++ -Wall str.cpp -fsyntax-only
str.cpp:7:27: warning: ‘strlen’ argument missing terminating nul
[-Wstringop-overflow=]
7 | auto zz = __builtin_strlen(aa[0]);
| ~~~~~~~~~~~~~~~~^~~~~~~
str.cpp:6:19: note: referenced argument declared here
6 | extern const char aa[1][2] = {{'2'}};
| ^~
str.cpp:7:27: warning: ‘strlen’ argument missing terminating nul
[-Wstringop-overflow=]
7 | auto zz = __builtin_strlen(aa[0]);
| ~~~~~~~~~~~~~~~~^~~~~~~
str.cpp:6:19: note: referenced argument declared here
6 | extern const char aa[1][2] = {{'2'}};
| ^~
str.cpp:7:32: warning: ‘strlen’ argument missing terminating nul
[-Wstringop-overflow=]
7 | auto zz = __builtin_strlen(aa[0]);
| ~~~~^
str.cpp:6:19: note: referenced argument declared here
6 | extern const char aa[1][2] = {{'2'}};
| ^~
Reduced example from real code at:
https://github.com/boostorg/date_time/blob/b0437e2999a65668dc4178dbb817a89a382ece94/include/boost/date_time/special_values_formatter.hpp#L89-L92
+
https://github.com/boostorg/date_time/blob/b0437e2999a65668dc4178dbb817a89a382ece94/include/boost/date_time/special_values_formatter.hpp#L43-L45
