https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106456
Bug ID: 106456
Summary: -Wunreachable-code seems very broken
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
I tried out this simple example:
extern void g( int);
int f( int a)
{
return 2 * a;
g( a);
}
gcc doesn't seem able to find the problem:
$ /home/dcb/gcc/results/bin/g++ -c -g -O2 -Wall -Wextra -Wunreachable-code
jul27d.cc
$
clang++ can:
$ clang++ -c -g -O2 -Wall -Wextra -Wunreachable-code jul27d.cc
jul27d.cc:7:2: warning: code will never be executed [-Wunreachable-code]
g( a);
^
1 warning generated.
$
Following on from this, there are a couple of examples in the gcc source code:
trunk.git/gcc/value-range-storage.h:149:3: style: Statements following return,
break, continue, goto or throw will never be executed. [unreachableCode]
trunk.git/gcc/value-range-storage.h:210:3: style: Statements following return,
break, continue, goto or throw will never be executed. [unreachableCode]
