r213725 - Improve diagnostic on default-initializing const variables (PR20208).
Nico Weber
nicolasweber at gmx.de
Tue Jul 22 22:16:11 PDT 2014
Author: nico
Date: Wed Jul 23 00:16:10 2014
New Revision: 213725
URL: http://llvm.org/viewvc/llvm-project?rev=213725&view=rev
Log:
Improve diagnostic on default-initializing const variables (PR20208).
This tweaks the diagnostic wording slighly, and adds a fixit on a note.
An alternative would be to add the fixit directly on the diagnostic, see
the review thread linked to from the bug for a few notes on that approach.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/SemaInit.cpp
cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
cfe/trunk/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp
cfe/trunk/test/CXX/dcl.decl/dcl.init/p6.cpp
cfe/trunk/test/CXX/drs/dr0xx.cpp
cfe/trunk/test/CXX/drs/dr4xx.cpp
cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
cfe/trunk/test/SemaCXX/constexpr-value-init.cpp
cfe/trunk/test/SemaCXX/cxx0x-cursory-default-delete.cpp
cfe/trunk/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Jul 23 00:16:10 2014
@@ -5203,7 +5203,9 @@ def err_address_space_qualified_delete :
def err_default_init_const : Error<
"default initialization of an object of const type %0"
- "%select{| requires a user-provided default constructor}1">;
+ "%select{| without a user-provided default constructor}1">;
+def note_add_initializer : Note<
+ "add an explicit initializer to initialize %0">;
def err_delete_operand : Error<"cannot delete expression of type %0">;
def ext_delete_void_ptr_operand : ExtWarn<
"cannot delete expression with pointer-to-'void' type %0">;
Modified: cfe/trunk/lib/Sema/SemaInit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaInit.cpp (original)
+++ cfe/trunk/lib/Sema/SemaInit.cpp Wed Jul 23 00:16:10 2014
@@ -6455,6 +6455,26 @@ static void diagnoseListInit(Sema &S, co
"Inconsistent init list check result.");
}
+/// Prints a fixit for adding a null initializer for |Entity|. Call this only
+/// right after emitting a diagnostic.
+static void maybeEmitZeroInitializationFixit(Sema &S,
+ InitializationSequence &Sequence,
+ const InitializedEntity &Entity) {
+ if (Entity.getKind() != InitializedEntity::EK_Variable)
+ return;
+
+ VarDecl *VD = cast<VarDecl>(Entity.getDecl());
+ if (VD->getInit() || VD->getLocEnd().isMacroID())
+ return;
+
+ QualType VariableTy = VD->getType().getCanonicalType();
+ SourceLocation Loc = S.getLocForEndOfToken(VD->getLocEnd());
+ std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
+
+ S.Diag(Loc, diag::note_add_initializer)
+ << VD << FixItHint::CreateInsertion(Loc, Init);
+}
+
bool InitializationSequence::Diagnose(Sema &S,
const InitializedEntity &Entity,
const InitializationKind &Kind,
@@ -6785,7 +6805,8 @@ bool InitializationSequence::Diagnose(Se
<< Entity.getName();
} else {
S.Diag(Kind.getLocation(), diag::err_default_init_const)
- << DestType << (bool)DestType->getAs<RecordType>();
+ << DestType << (bool)DestType->getAs<RecordType>();
+ maybeEmitZeroInitializationFixit(S, *this, Entity);
}
break;
Modified: cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp (original)
+++ cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p9.cpp Wed Jul 23 00:16:10 2014
@@ -17,7 +17,7 @@ extern int (*const d)(int);
// A variable declaration which uses the constexpr specifier shall have an
// initializer and shall be initialized by a constant expression.
-constexpr int ni1; // expected-error {{default initialization of an object of const type 'const int'}}
+constexpr int ni1; // expected-error {{default initialization of an object of const type 'const int'}} expected-note {{add an explicit initializer to initialize 'ni1'}}
constexpr struct C { C(); } ni2; // expected-error {{cannot have non-literal type 'const struct C'}} expected-note 3{{has no constexpr constructors}}
constexpr double &ni3; // expected-error {{declaration of reference variable 'ni3' requires an initializer}}
@@ -34,4 +34,4 @@ struct pixel {
int x, y;
};
constexpr pixel ur = { 1294, 1024 }; // ok
-constexpr pixel origin; // expected-error {{default initialization of an object of const type 'const pixel' requires a user-provided default constructor}}
+constexpr pixel origin; // expected-error {{default initialization of an object of const type 'const pixel' without a user-provided default constructor}} expected-note {{add an explicit initializer to initialize 'origin'}}
Modified: cfe/trunk/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp (original)
+++ cfe/trunk/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp Wed Jul 23 00:16:10 2014
@@ -36,7 +36,7 @@ struct S3 {
constexpr S3 s3a = S3(0);
constexpr S3 s3b = s3a;
constexpr S3 s3c = S3();
-constexpr S3 s3d; // expected-error {{default initialization of an object of const type 'const S3' requires a user-provided default constructor}}
+constexpr S3 s3d; // expected-error {{default initialization of an object of const type 'const S3' without a user-provided default constructor}} expected-note{{add an explicit initializer to initialize 's3d'}}
struct S4 {
S4() = default;
@@ -119,6 +119,6 @@ namespace PR13492 {
};
void f() {
- const B b; // expected-error {{default initialization of an object of const type 'const PR13492::B' requires a user-provided default constructor}}
+ const B b; // expected-error {{default initialization of an object of const type 'const PR13492::B' without a user-provided default constructor}} expected-note {{add an explicit initializer to initialize 'b'}}
}
}
Modified: cfe/trunk/test/CXX/dcl.decl/dcl.init/p6.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.decl/dcl.init/p6.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.decl/dcl.init/p6.cpp (original)
+++ cfe/trunk/test/CXX/dcl.decl/dcl.init/p6.cpp Wed Jul 23 00:16:10 2014
@@ -10,15 +10,15 @@ struct NoUserDefault : public MakeNonPOD
struct HasUserDefault { HasUserDefault(); };
void test_const_default_init() {
- const NoUserDefault x1; // expected-error{{default initialization of an object of const type 'const NoUserDefault' requires a user-provided default constructor}}
+ const NoUserDefault x1; // expected-error{{default initialization of an object of const type 'const NoUserDefault' without a user-provided default constructor}} expected-note {{add an explicit initializer to initialize 'x1'}}
const HasUserDefault x2;
- const int x3; // expected-error{{default initialization of an object of const type 'const int'}}
+ const int x3; // expected-error{{default initialization of an object of const type 'const int'}} expected-note{{add an explicit initializer to initialize 'x3'}}
}
// rdar://8501008
struct s0 {};
struct s1 { static const s0 foo; };
-const struct s0 s1::foo; // expected-error{{default initialization of an object of const type 'const struct s0' requires a user-provided default constructor}}
+const struct s0 s1::foo; // expected-error{{default initialization of an object of const type 'const struct s0' without a user-provided default constructor}} expected-note {{add an explicit initializer to initialize 'foo'}}
template<typename T>
struct s2 {
Modified: cfe/trunk/test/CXX/drs/dr0xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr0xx.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr0xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr0xx.cpp Wed Jul 23 00:16:10 2014
@@ -852,7 +852,7 @@ namespace dr77 { // dr77: yes
namespace dr78 { // dr78: sup ????
// Under DR78, this is valid, because 'k' has static storage duration, so is
// zero-initialized.
- const int k; // expected-error {{default initialization of an object of const}}
+ const int k; // expected-error {{default initialization of an object of const}} expected-note{{add an explicit initializer to initialize 'k'}}
}
// dr79: na
Modified: cfe/trunk/test/CXX/drs/dr4xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr4xx.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr4xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr4xx.cpp Wed Jul 23 00:16:10 2014
@@ -1201,7 +1201,7 @@ namespace dr497 { // dr497: yes
struct S {
mutable int i;
};
- const S cs; // expected-error {{default initialization}}
+ const S cs; // expected-error {{default initialization}} expected-note {{add an explicit initializer}}
int S::*pm = &S::i;
cs.*pm = 88;
}
Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Wed Jul 23 00:16:10 2014
@@ -1177,7 +1177,7 @@ namespace ExternConstexpr {
void f() {
extern constexpr int i; // expected-error {{constexpr variable declaration must be a definition}}
constexpr int j = 0;
- constexpr int k; // expected-error {{default initialization of an object of const type}}
+ constexpr int k; // expected-error {{default initialization of an object of const type}} expected-note{{add an explicit initializer to initialize 'k'}}
}
}
Modified: cfe/trunk/test/SemaCXX/constexpr-value-init.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constexpr-value-init.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constexpr-value-init.cpp (original)
+++ cfe/trunk/test/SemaCXX/constexpr-value-init.cpp Wed Jul 23 00:16:10 2014
@@ -14,7 +14,7 @@ void f() {
constexpr A a; // expected-error {{constant expression}} expected-note {{in call to 'A()'}}
}
-constexpr B b1; // expected-error {{requires a user-provided default constructor}}
+constexpr B b1; // expected-error {{without a user-provided default constructor}} expected-note {{add an explicit initializer to initialize 'b1'}}
constexpr B b2 = B(); // ok
static_assert(b2.a.a == 1, "");
static_assert(b2.a.b == 2, "");
@@ -23,9 +23,9 @@ struct C {
int c;
};
struct D : C { int d; };
-constexpr C c1; // expected-error {{requires a user-provided default constructor}}
+constexpr C c1; // expected-error {{without a user-provided default constructor}} expected-note{{add an explicit initializer to initialize 'c1'}}
constexpr C c2 = C(); // ok
-constexpr D d1; // expected-error {{requires a user-provided default constructor}}
+constexpr D d1; // expected-error {{without a user-provided default constructor}} expected-note{{add an explicit initializer to initialize 'd1'}}
constexpr D d2 = D(); // ok with DR1452
static_assert(D().c == 0, "");
static_assert(D().d == 0, "");
Modified: cfe/trunk/test/SemaCXX/cxx0x-cursory-default-delete.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx0x-cursory-default-delete.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/cxx0x-cursory-default-delete.cpp (original)
+++ cfe/trunk/test/SemaCXX/cxx0x-cursory-default-delete.cpp Wed Jul 23 00:16:10 2014
@@ -25,7 +25,7 @@ void fn1 () {
non_const_copy ncc2 = ncc;
ncc = ncc2;
const non_const_copy cncc{};
- const non_const_copy cncc1; // expected-error {{default initialization of an object of const type 'const non_const_copy' requires a user-provided default constructor}}
+ const non_const_copy cncc1; // expected-error {{default initialization of an object of const type 'const non_const_copy' without a user-provided default constructor}} expected-note {{add an explicit initializer to initialize 'cncc1'}}
non_const_copy ncc3 = cncc; // expected-error {{no matching}}
ncc = cncc; // expected-error {{no viable overloaded}}
};
Modified: cfe/trunk/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1y-variable-templates_in_class.cpp?rev=213725&r1=213724&r2=213725&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/cxx1y-variable-templates_in_class.cpp (original)
+++ cfe/trunk/test/SemaCXX/cxx1y-variable-templates_in_class.cpp Wed Jul 23 00:16:10 2014
@@ -58,13 +58,13 @@ namespace out_of_line {
template<typename T, typename T0> static CONST T b = T(100);
template<typename T> static CONST T b<T,int>;
};
- template<typename T, typename T0> CONST T B4::a; // expected-error {{default initialization of an object of const type 'const int'}}
+ template<typename T, typename T0> CONST T B4::a; // expected-error {{default initialization of an object of const type 'const int'}} expected-note {{add an explicit initializer to initialize 'a<int, char>'}}
template<typename T> CONST T B4::a<T,int>;
template CONST int B4::a<int,char>; // expected-note {{in instantiation of}}
template CONST int B4::a<int,int>;
template<typename T, typename T0> CONST T B4::b;
- template<typename T> CONST T B4::b<T,int>; // expected-error {{default initialization of an object of const type 'const int'}}
+ template<typename T> CONST T B4::b<T,int>; // expected-error {{default initialization of an object of const type 'const int'}} expected-note {{add an explicit initializer to initialize 'b<int, int>'}}
template CONST int B4::b<int,char>;
template CONST int B4::b<int,int>; // expected-note {{in instantiation of}}
}
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