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Re: [C++ Patch] Fix confusing diagnostics for invalid overrides
On 03/25/2018 08:48 PM, Paolo Carlini wrote:
Hi Volker
On 25 Mar 2018, at 16:18, Volker Reichelt <v.reichelt@netcologne.de> wrote:
Hi,
when overriding a virtual function fails, the C++ front-end usually
emits two errors: one for the override that fails and one for the
function that is overridden. The second error is confusing and
should be replaced by a note to be in line with other diagnostics.
The attached patch just does that: It replaces the error/error pattern
by an error/inform pattern in search.c (check_final_overrider). And it
replaces the affected dg-error marks in the testsuite by dg-message.
Since you are correctly using DECL_SOURCE_LOCATION, I would recommend removing the ‘+’ modifiers, which in that case are redundant anyway and are known be a little cryptic and even causing tricky bugs together with warnings.
Cheers,
Paolo
Thanks, Paolo.
Below is an updated patch without the redundant "+" modifiers.
On 03/26/2018 12:33 AM, Paolo Carlini wrote:
On 25/03/2018 21:08, Paolo Carlini wrote:
... oh, please also double check that with 'F' you don't need the
general location_of instead of D_S_L, which normally goes with 'D' -
I don't have my machines at hand to do it myself, sorry.
Just checked, DECL_SOURCE_LOCATION is fine.
Paolo.
I also checked that DECL_SOURCE_LOCATION with %qF is OK.
In all the other places in the C++ frontend where %q#F or %qF is
used, DECL_SOURCE_LOCATION() is used for the corresponding argument:
call.c (joust)
decl.c (wrapup_namespace_globals)
decl.c (check_redeclaration_exception_specification)
method.c (maybe_explain_implicit_delete)
I also checked the output for that specific case manually.
Bootstrapped and regtested on x86_64-pc-linux-gnu.
OK for trunk?
Regards,
Volker
2018-03-25 Volker Reichelt <v.reichelt@netcologne.de>
* search.c (check_final_overrider): Use inform instead of error
for the diagnostics of the overridden functions.
Index: gcc/cp/search.c
===================================================================
--- gcc/cp/search.c (revision 258835)
+++ gcc/cp/search.c (working copy)
@@ -1918,12 +1918,12 @@
if (fail == 1)
{
error ("invalid covariant return type for %q+#D", overrider);
- error (" overriding %q+#D", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn), " overriding %q#D", basefn);
}
else
{
error ("conflicting return type specified for %q+#D", overrider);
- error (" overriding %q+#D", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn), " overriding %q#D", basefn);
}
DECL_INVALID_OVERRIDER_P (overrider) = 1;
return 0;
@@ -1938,7 +1938,7 @@
if (!comp_except_specs (base_throw, over_throw, ce_derived))
{
error ("looser throw specifier for %q+#F", overrider);
- error (" overriding %q+#F", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn), " overriding %q#F", basefn);
DECL_INVALID_OVERRIDER_P (overrider) = 1;
return 0;
}
@@ -1950,7 +1950,7 @@
&& !tx_safe_fn_type_p (over_type))
{
error ("conflicting type attributes specified for %q+#D",
overrider);
- error (" overriding %q+#D", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn), " overriding %q#D", basefn);
DECL_INVALID_OVERRIDER_P (overrider) = 1;
return 0;
}
@@ -1975,13 +1975,15 @@
if (DECL_DELETED_FN (overrider))
{
error ("deleted function %q+D", overrider);
- error ("overriding non-deleted function %q+D", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn),
+ "overriding non-deleted function %qD", basefn);
maybe_explain_implicit_delete (overrider);
}
else
{
error ("non-deleted function %q+D", overrider);
- error ("overriding deleted function %q+D", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn),
+ "overriding deleted function %qD", basefn);
}
return 0;
}
@@ -1988,7 +1990,8 @@
if (DECL_FINAL_P (basefn))
{
error ("virtual function %q+D", overrider);
- error ("overriding final function %q+D", basefn);
+ inform (DECL_SOURCE_LOCATION (basefn),
+ "overriding final function %qD", basefn);
return 0;
}
return 1;
===================================================================
2018-03-25 Volker Reichelt <v.reichelt@netcologne.de>
* g++.dg/cpp0x/defaulted2.C: Use dg-message instead of dg-error
for the diagnostics of overridden functions.
* g++.dg/cpp0x/implicit1.C: Likewise.
* g++.dg/cpp0x/override1.C: Likewise.
* g++.dg/eh/shadow1.C: Likewise.
* g++.dg/inherit/covariant12.C: Likewise.
* g++.dg/inherit/covariant14.C: Likewise.
* g++.dg/inherit/covariant15.C: Likewise.
* g++.dg/inherit/covariant16.C: Likewise.
* g++.dg/inherit/crash3.C: Likewise.
* g++.dg/inherit/error2.C: Likewise.
* g++.dg/template/crash100.C: Likewise.
* g++.old-deja/g++.eh/spec6.C: Likewise.
* g++.old-deja/g++.mike/p811.C: Likewise.
* g++.old-deja/g++.other/virtual11.C: Likewise.
* g++.old-deja/g++.other/virtual4.C: Likewise.
Index: gcc/testsuite/g++.dg/cpp0x/defaulted2.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/defaulted2.C (revision 258835)
+++ gcc/testsuite/g++.dg/cpp0x/defaulted2.C (working copy)
@@ -25,7 +25,7 @@
struct C
{
- virtual void f() = delete; // { dg-error "overriding deleted" }
+ virtual void f() = delete; // { dg-message "overriding deleted" }
};
struct D: public C
Index: gcc/testsuite/g++.dg/cpp0x/implicit1.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/implicit1.C (revision 258835)
+++ gcc/testsuite/g++.dg/cpp0x/implicit1.C (working copy)
@@ -7,7 +7,7 @@
{
void operator delete (void *); // { dg-message "private" }
public:
- virtual ~C(); // { dg-error "overriding" }
+ virtual ~C(); // { dg-message "overriding" }
};
struct D: C { }; // { dg-error "deleted" }
@@ -20,7 +20,7 @@
struct F
{
- virtual ~F(); // { dg-error "overriding" }
+ virtual ~F(); // { dg-message "overriding" }
};
struct G: E, F { }; // { dg-error "deleted" }
Index: gcc/testsuite/g++.dg/cpp0x/override1.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/override1.C (revision 258835)
+++ gcc/testsuite/g++.dg/cpp0x/override1.C (working copy)
@@ -7,7 +7,7 @@
virtual void y() final;
};
-void B::y() {} // { dg-error "overriding" }
+void B::y() {} // { dg-message "overriding" }
struct B2
{
@@ -16,7 +16,7 @@
struct D : B
{
- virtual void g() override final {} // { dg-error "overriding" }
+ virtual void g() override final {} // { dg-message "overriding" }
virtual void y() override final {} // { dg-error "virtual" }
};
Index: gcc/testsuite/g++.dg/eh/shadow1.C
===================================================================
--- gcc/testsuite/g++.dg/eh/shadow1.C (revision 258835)
+++ gcc/testsuite/g++.dg/eh/shadow1.C (working copy)
@@ -13,7 +13,7 @@
friend class E;
static B *baz (D *);
- virtual void V () throw (B); // { dg-error "overriding" "" { target
{ ! c++17 } } }
+ virtual void V () throw (B); // { dg-message "overriding" "" {
target { ! c++17 } } }
}; // { dg-error "dynamic exception specification" "" {
target c++17 } .-1 }
// { dg-warning "deprecated" "" { target { c++11 && {
! c++17 } } } .-2 }
struct E : public D
Index: gcc/testsuite/g++.dg/inherit/covariant12.C
===================================================================
--- gcc/testsuite/g++.dg/inherit/covariant12.C (revision 258835)
+++ gcc/testsuite/g++.dg/inherit/covariant12.C (working copy)
@@ -9,7 +9,7 @@
struct B
{
- virtual T *Foo (); // { dg-error "overriding" }
+ virtual T *Foo (); // { dg-message "overriding" }
};
struct D : B
Index: gcc/testsuite/g++.dg/inherit/covariant14.C
===================================================================
--- gcc/testsuite/g++.dg/inherit/covariant14.C (revision 258835)
+++ gcc/testsuite/g++.dg/inherit/covariant14.C (working copy)
@@ -8,7 +8,7 @@
struct B
{
- virtual A* foo(); // { dg-error "overriding" }
+ virtual A* foo(); // { dg-message "overriding" }
};
namespace N
Index: gcc/testsuite/g++.dg/inherit/covariant15.C
===================================================================
--- gcc/testsuite/g++.dg/inherit/covariant15.C (revision 258835)
+++ gcc/testsuite/g++.dg/inherit/covariant15.C (working copy)
@@ -5,7 +5,7 @@
class B : A
{
- virtual A* foo(); /* { dg-error "overriding" } */
+ virtual A* foo(); /* { dg-message "overriding" } */
};
struct C : virtual B
Index: gcc/testsuite/g++.dg/inherit/covariant16.C
===================================================================
--- gcc/testsuite/g++.dg/inherit/covariant16.C (revision 258835)
+++ gcc/testsuite/g++.dg/inherit/covariant16.C (working copy)
@@ -8,7 +8,7 @@
struct B : virtual A
{
- virtual B* foo(); /* { dg-error "overriding" } */
+ virtual B* foo(); /* { dg-message "overriding" } */
};
struct C : B
Index: gcc/testsuite/g++.dg/inherit/crash3.C
===================================================================
--- gcc/testsuite/g++.dg/inherit/crash3.C (revision 258835)
+++ gcc/testsuite/g++.dg/inherit/crash3.C (working copy)
@@ -2,7 +2,7 @@
struct A
{
- virtual int& foo(); // { dg-error "overriding" }
+ virtual int& foo(); // { dg-message "overriding" }
};
struct B : A
Index: gcc/testsuite/g++.dg/inherit/error2.C
===================================================================
--- gcc/testsuite/g++.dg/inherit/error2.C (revision 258835)
+++ gcc/testsuite/g++.dg/inherit/error2.C (working copy)
@@ -3,7 +3,7 @@
struct A
{
- virtual A* foo(); // { dg-error "overriding" }
+ virtual A* foo(); // { dg-message "overriding" }
};
struct B : virtual A; // { dg-error "before" }
Index: gcc/testsuite/g++.dg/template/crash100.C
===================================================================
--- gcc/testsuite/g++.dg/template/crash100.C (revision 258835)
+++ gcc/testsuite/g++.dg/template/crash100.C (working copy)
@@ -7,7 +7,7 @@
public:
operator T&(void) { return Val; }
- virtual T& operator=(T a ) // { dg-error "overriding" }
+ virtual T& operator=(T a ) // { dg-message "overriding" }
{
Val = a;
return Val;
Index: gcc/testsuite/g++.old-deja/g++.eh/spec6.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.eh/spec6.C (revision 258835)
+++ gcc/testsuite/g++.old-deja/g++.eh/spec6.C (working copy)
@@ -81,19 +81,19 @@
struct H : private E {};
struct A
{
- virtual void foo() throw(); // { dg-error "" } overriding
+ virtual void foo() throw(); // { dg-message "" } overriding
virtual void baz() throw(double, int);
virtual void bar();
virtual void qux() throw(E);
- virtual void qux(int) throw(E const *); // { dg-error "" } overriding
(pedantically)
- virtual void quux() throw(F); // { dg-error "" } overriding
- virtual void quux(int) throw(F *); // { dg-error "" } overriding
- virtual void wibble() throw(E); // { dg-error "" } overriding
- virtual void wobble() throw(E *); // { dg-error "" } overriding
- virtual void wobble(int) throw(E *); // { dg-error "" } overriding
+ virtual void qux(int) throw(E const *); // { dg-message "" }
overriding (pedantically)
+ virtual void quux() throw(F); // { dg-message "" } overriding
+ virtual void quux(int) throw(F *); // { dg-message "" } overriding
+ virtual void wibble() throw(E); // { dg-message "" } overriding
+ virtual void wobble() throw(E *); // { dg-message "" } overriding
+ virtual void wobble(int) throw(E *); // { dg-message "" } overriding
virtual void wabble(int) throw(E *);
virtual void wubble(int) throw(E *, H *);
- virtual ~A() throw(); // { dg-error "" } overriding
+ virtual ~A() throw(); // { dg-message "" } overriding
};
struct B : A
@@ -115,7 +115,7 @@
struct A1
{
virtual void foo() throw(int);
- virtual void bar() throw(); // { dg-error "" } overriding
+ virtual void bar() throw(); // { dg-message "" } overriding
virtual ~A1() throw(int);
};
Index: gcc/testsuite/g++.old-deja/g++.mike/p811.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.mike/p811.C (revision 258835)
+++ gcc/testsuite/g++.old-deja/g++.mike/p811.C (working copy)
@@ -512,7 +512,7 @@
public:
Y() {}
virtual const char *stringify() = 0;
- virtual char *stringify2() const = 0; // { dg-error "overriding" }
+ virtual char *stringify2() const = 0; // { dg-message "overriding" }
};
class X: public Y { // { dg-message "defined here" }
Index: gcc/testsuite/g++.old-deja/g++.other/virtual11.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.other/virtual11.C (revision 258835)
+++ gcc/testsuite/g++.old-deja/g++.other/virtual11.C (working copy)
@@ -12,7 +12,7 @@
struct B
{
- virtual void foo (); // { dg-error "" } of this function
+ virtual void foo (); // { dg-message "" } of this function
};
struct C : A , B
Index: gcc/testsuite/g++.old-deja/g++.other/virtual4.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.other/virtual4.C (revision 258835)
+++ gcc/testsuite/g++.old-deja/g++.other/virtual4.C (working copy)
@@ -2,7 +2,7 @@
class A {
public:
- virtual int foo() = 0; // { dg-error "" } original definition
+ virtual int foo() = 0; // { dg-message "" } original definition
};
class B {
===================================================================