https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117329
Bug ID: 117329
Summary: -Wnull-dereference error indicator in the wrong place
when inlining methods.
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: o.putaans at gmail dot com
Target Milestone: ---
Created attachment 59471
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59471&action=edit
Preprocessed source file.
gcc version 14.2.0 (Ubuntu 14.2.0-4ubuntu2~24.04)
Target: x86_64-linux-gnu
When compiling the code with `g++-14 -O1 -Wnull-dereference main.cpp`
The compiler returns a warning
```
In member function ‘void T2::setVar(int)’,
inlined from ‘int main()’ at main.cpp:22:22:
main.cpp:6:13: warning: null pointer dereference [-Wnull-dereference]
6 | var = a;
| ~~~~^~~
```
The same warning was found for other -OX where X > 1. -O0 did not report this
warning at all.
That reported warning is in the wrong place. It seems to report the hidden
`this` variable in that line as being null, but it should have been reported
far earlier - the 3rd to last line `t->getA()->setVar(5);` as t is the variable
that is being null dereferenced. I'd expect that line to be reported
This is a simplified version of what I encountered in the wild and that code
had a potential null pointer dereference, but this is close enough to what I
could isolate.
