https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84203
Bug ID: 84203
Summary: add -Wsuggest-attribute=returns_nonnull
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The option -Wsuggest-attribute= helps improve code generation by annotating
function declarations with attributes like cold, const, pure, malloc and
noreturn. However, the option doesn't make it possible to request suggestions
for the returns_nonnull attribute. Especially in C++ where functions returning
newly allocated memory often never return null (because they throw on failure
to allocate), making use of the attribute could further improve generated code.
$ cat t.C && gcc -Wall -Wextra -O -S -Wsuggest-attribute=noreturn t.C
int f () // -Wsuggest-attribute=noreturn here (good)
{
throw "not implemented";
}
void* f (unsigned n) // missing -Wsuggest-attribute=returns_nonnull
{
return new char[n];
}
t.C: In function ‘int f()’:
t.C:1:5: warning: function might be candidate for attribute ‘noreturn’
[-Wsuggest-attribute=noreturn]
int f () // -Wsuggest-attribute=noreturn here (good)
^
