https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82334
Bug ID: 82334
Summary: improve list of candidates for a member definition
that doesn't match declaration
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
When the prototype of a member function definition doesn't match its
declaration GCC prints an error followed by a list of candidate overloads of
the member function. That helpful but not as much as it could be. It would be
even more useful if the note for each candidate indicated the way in which it
differs from the prototype of the definition, e.g., by underlining a missing
qualifier.
The test case below shows how the current note is less than optimal:
$ cat a.C && gcc -O2 -S -Wall -Wextra a.C
struct S {
typedef int descriptor_t;
typedef double real_t;
typedef const char *strptr_t;
typedef void *handle_t;
int f (int, double, const char*, void*) const;
};
int S::f (descriptor_t, real_t, strptr_t, handle_t)
{
return 0;
}
a.C:10:5: error: no declaration matches ‘int S::f(S::descriptor_t, S::real_t,
S::strptr_t, S::handle_t)’
int S::f (descriptor_t, real_t, strptr_t, handle_t)
^
a.C:7:7: note: candidate is: ‘int S::f(int, double, const char*, void*) const’
int f (int, double, const char*, void*) const;
^
a.C:1:8: note: ‘struct S’ defined here
struct S {
^
In contrast, Clang emits a more helpful note:
.C:10:8: error: out-of-line definition of 'f' does not match any declaration in
'S'
int S::f (descriptor_t, real_t, strptr_t, handle_t)
^
t.C:7:7: note: member declaration does not match because it is const qualified
int f (int, double, const char*, void*) const;
^ ~~~~~
1 error generated.
