https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92289
Bug ID: 92289
Summary: Worse "control reaches end of non-void function"
diagnostic with undefined sanitizer
Product: gcc
Version: 9.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: TonyELewis at hotmail dot com
Target Milestone: ---
When I use Godbolt's GCC (9.2 or trunk ("10.0.0 20191022 (experimental)")) to
compile:
~~~
void throw_sum( int a, int b ) { throw a + b; }
#define THROW_WITH_LINE_NUM_ADDED( x ) throw_sum( x, __LINE__ )
bool f( const bool &prm_val ) {
if ( prm_val ) { return true; }
THROW_WITH_LINE_NUM_ADDED( 0 );
}
~~~
...with `-Werror` I get a helpful warning (promoted to error):
~~~
<source>: In function 'bool f(const bool&)':
<source>:9:1: error: control reaches end of non-void function
[-Werror=return-type]
9 | }
| ^
cc1plus: all warnings being treated as errors
Compiler returned: 1
~~~
...but if I turn on UBSan (ie change the options to `-Werror
-fsanitize=undefined`), I get:
~~~
<source>: In function 'bool f(const bool&)':
<source>:3:49: error: control reaches end of non-void function
[-Werror=return-type]
3 | #define THROW_WITH_LINE_NUM_ADDED( x ) throw_sum( x, __LINE__ )
| ~~~~~~~~~^~~~~~~~~~~~~~~
<source>:8:4: note: in expansion of macro 'THROW_WITH_LINE_NUM_ADDED'
8 | THROW_WITH_LINE_NUM_ADDED( 0 );
| ^~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
Compiler returned: 1
~~~
...which I think is much less helpful. I don't think that enabling runtime
sanitizer checks should reduce the quality of the compiler's diagnostics.
Thanks very much to all who work on GCC.
