r206135 - Improve error recovery around colon.
Serge Pavlov
sepavloff at gmail.com
Sun Apr 13 09:52:03 PDT 2014
Author: sepavloff
Date: Sun Apr 13 11:52:03 2014
New Revision: 206135
URL: http://llvm.org/viewvc/llvm-project?rev=206135&view=rev
Log:
Improve error recovery around colon.
Parse of nested name spacifier is modified so that it properly recovers
if colon is mistyped as double colon in case statement.
This patch fixes PR15133.
Differential Revision: http://llvm-reviews.chandlerc.com/D2870
Modified:
cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Parse/ParseExprCXX.cpp
cfe/trunk/lib/Parse/ParseStmt.cpp
cfe/trunk/lib/Parse/ParseTemplate.cpp
cfe/trunk/lib/Sema/SemaCXXScopeSpec.cpp
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/test/Parser/recovery.cpp
cfe/trunk/test/SemaCXX/nested-name-spec.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td Sun Apr 13 11:52:03 2014
@@ -339,8 +339,10 @@ def err_templated_using_directive : Erro
"cannot template a using directive">;
def err_templated_using_declaration : Error<
"cannot template a using declaration">;
-def err_unexected_colon_in_nested_name_spec : Error<
+def err_unexpected_colon_in_nested_name_spec : Error<
"unexpected ':' in nested name specifier; did you mean '::'?">;
+def err_unexpected_token_in_nested_name_spec : Error<
+ "'%0' cannot be a part of nested name specifier; did you mean ':'?">;
def err_bool_redeclaration : Error<
"redeclaration of C++ built-in type 'bool'">;
def ext_c11_static_assert : Extension<
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Sun Apr 13 11:52:03 2014
@@ -1169,7 +1169,10 @@ def err_incomplete_type : Error<
def warn_cxx98_compat_enum_nested_name_spec : Warning<
"enumeration type in nested name specifier is incompatible with C++98">,
InGroup<CXX98Compat>, DefaultIgnore;
-
+def err_nested_name_spec_is_not_class : Error<
+ "%0 cannot appear before '::' because it is not a class"
+ "%select{ or namespace|, namespace, or scoped enumeration}1; did you mean ':'?">;
+
// C++ class members
def err_storageclass_invalid_for_member : Error<
"storage class specified for a member declaration">;
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Sun Apr 13 11:52:03 2014
@@ -4424,7 +4424,8 @@ public:
bool EnteringContext,
CXXScopeSpec &SS,
NamedDecl *ScopeLookupResult,
- bool ErrorRecoveryLookup);
+ bool ErrorRecoveryLookup,
+ bool *IsCorrectedToColon = 0);
/// \brief The parser has parsed a nested-name-specifier 'identifier::'.
///
@@ -4447,6 +4448,13 @@ public:
/// output parameter (containing the full nested-name-specifier,
/// including this new type).
///
+ /// \param ErrorRecoveryLookup If true, then this method is called to improve
+ /// error recovery. In this case do not emit error message.
+ ///
+ /// \param IsCorrectedToColon If not null, suggestions to replace '::' -> ':'
+ /// are allowed. The bool value pointed by this parameter is set to 'true'
+ /// if the identifier is treated as if it was followed by ':', not '::'.
+ ///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXNestedNameSpecifier(Scope *S,
IdentifierInfo &Identifier,
@@ -4454,7 +4462,9 @@ public:
SourceLocation CCLoc,
ParsedType ObjectType,
bool EnteringContext,
- CXXScopeSpec &SS);
+ CXXScopeSpec &SS,
+ bool ErrorRecoveryLookup = false,
+ bool *IsCorrectedToColon = 0);
ExprResult ActOnDecltypeExpression(Expr *E);
Modified: cfe/trunk/lib/Parse/ParseExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseExprCXX.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseExprCXX.cpp (original)
+++ cfe/trunk/lib/Parse/ParseExprCXX.cpp Sun Apr 13 11:52:03 2014
@@ -365,15 +365,15 @@ bool Parser::ParseOptionalCXXScopeSpecif
// Consume the template-id token.
ConsumeToken();
-
+
assert(Tok.is(tok::coloncolon) && "NextToken() not working properly!");
SourceLocation CCLoc = ConsumeToken();
HasScopeSpecifier = true;
-
+
ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
TemplateId->NumArgs);
-
+
if (Actions.ActOnCXXNestedNameSpecifier(getCurScope(),
SS,
TemplateId->TemplateKWLoc,
@@ -393,7 +393,6 @@ bool Parser::ParseOptionalCXXScopeSpecif
continue;
}
-
// The rest of the nested-name-specifier possibilities start with
// tok::identifier.
if (Tok.isNot(tok::identifier))
@@ -418,9 +417,8 @@ bool Parser::ParseOptionalCXXScopeSpecif
// error, but they probably meant something else strange so don't
// recover like this.
PP.LookAhead(1).is(tok::identifier)) {
- Diag(Next, diag::err_unexected_colon_in_nested_name_spec)
+ Diag(Next, diag::err_unexpected_colon_in_nested_name_spec)
<< FixItHint::CreateReplacement(Next.getLocation(), "::");
-
// Recover as if the user wrote '::'.
Next.setKind(tok::coloncolon);
}
@@ -434,23 +432,52 @@ bool Parser::ParseOptionalCXXScopeSpecif
return false;
}
+ if (ColonIsSacred) {
+ const Token &Next2 = GetLookAheadToken(2);
+ if (Next2.is(tok::kw_private) || Next2.is(tok::kw_protected) ||
+ Next2.is(tok::kw_public) || Next2.is(tok::kw_virtual)) {
+ Diag(Next2, diag::err_unexpected_token_in_nested_name_spec)
+ << Next2.getName()
+ << FixItHint::CreateReplacement(Next.getLocation(), ":");
+ Token ColonColon;
+ PP.Lex(ColonColon);
+ ColonColon.setKind(tok::colon);
+ PP.EnterToken(ColonColon);
+ break;
+ }
+ }
+
if (LastII)
*LastII = &II;
// We have an identifier followed by a '::'. Lookup this name
// as the name in a nested-name-specifier.
+ Token Identifier = Tok;
SourceLocation IdLoc = ConsumeToken();
assert((Tok.is(tok::coloncolon) || Tok.is(tok::colon)) &&
"NextToken() not working properly!");
+ Token ColonColon = Tok;
SourceLocation CCLoc = ConsumeToken();
CheckForLParenAfterColonColon();
- HasScopeSpecifier = true;
+ bool IsCorrectedToColon = false;
+ bool *CorrectionFlagPtr = ColonIsSacred ? &IsCorrectedToColon : 0;
if (Actions.ActOnCXXNestedNameSpecifier(getCurScope(), II, IdLoc, CCLoc,
- ObjectType, EnteringContext, SS))
+ ObjectType, EnteringContext, SS,
+ false, CorrectionFlagPtr)) {
+ // Identifier is not recognized as a nested name, but we can have
+ // mistyped '::' instead of ':'.
+ if (CorrectionFlagPtr && IsCorrectedToColon) {
+ ColonColon.setKind(tok::colon);
+ PP.EnterToken(Tok);
+ PP.EnterToken(ColonColon);
+ Tok = Identifier;
+ break;
+ }
SS.SetInvalid(SourceRange(IdLoc, CCLoc));
-
+ }
+ HasScopeSpecifier = true;
continue;
}
Modified: cfe/trunk/lib/Parse/ParseStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseStmt.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseStmt.cpp (original)
+++ cfe/trunk/lib/Parse/ParseStmt.cpp Sun Apr 13 11:52:03 2014
@@ -643,8 +643,9 @@ StmtResult Parser::ParseCaseStatement(bo
ColonProtection.restore();
if (TryConsumeToken(tok::colon, ColonLoc)) {
- } else if (TryConsumeToken(tok::semi, ColonLoc)) {
- // Treat "case blah;" as a typo for "case blah:".
+ } else if (TryConsumeToken(tok::semi, ColonLoc) ||
+ TryConsumeToken(tok::coloncolon, ColonLoc)) {
+ // Treat "case blah;" or "case blah::" as a typo for "case blah:".
Diag(ColonLoc, diag::err_expected_after)
<< "'case'" << tok::colon
<< FixItHint::CreateReplacement(ColonLoc, ":");
Modified: cfe/trunk/lib/Parse/ParseTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseTemplate.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseTemplate.cpp (original)
+++ cfe/trunk/lib/Parse/ParseTemplate.cpp Sun Apr 13 11:52:03 2014
@@ -1161,6 +1161,7 @@ bool
Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) {
// Template argument lists are constant-evaluation contexts.
EnterExpressionEvaluationContext EvalContext(Actions,Sema::ConstantEvaluated);
+ ColonProtectionRAIIObject ColonProtection(*this, false);
do {
ParsedTemplateArgument Arg = ParseTemplateArgument();
Modified: cfe/trunk/lib/Sema/SemaCXXScopeSpec.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCXXScopeSpec.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaCXXScopeSpec.cpp (original)
+++ cfe/trunk/lib/Sema/SemaCXXScopeSpec.cpp Sun Apr 13 11:52:03 2014
@@ -377,6 +377,28 @@ class NestedNameSpecifierValidatorCCC :
/// by ActOnCXXNestedNameSpecifier.
///
/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
+/// that it contains an extra parameter \p ScopeLookupResult.
+///
+/// \param S Scope in which the nested-name-specifier occurs.
+/// \param Identifier Identifier in the sequence "identifier" "::".
+/// \param IdentifierLoc Location of the \p Identifier.
+/// \param CCLoc Location of "::" following Identifier.
+/// \param ObjectType Type of postfix expression if the nested-name-specifier
+/// occurs in construct like: <tt>ptr->nns::f</tt>.
+/// \param EnteringContext If true, enter the context specified by the
+/// nested-name-specifier.
+/// \param SS Optional nested name specifier preceding the identifier.
+/// \param ScopeLookupResult Provides the result of name lookup within the
+/// scope of the nested-name-specifier that was computed at template
+/// definition time.
+/// \param ErrorRecoveryLookup Specifies if the method is called to improve
+/// error recovery and what kind of recovery is performed.
+/// \param IsCorrectedToColon If not null, suggestion of replace '::' -> ':'
+/// are allowed. The bool value pointed by this parameter is set to
+/// 'true' if the identifier is treated as if it was followed by ':',
+/// not '::'.
+///
+/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
/// that it contains an extra parameter \p ScopeLookupResult, which provides
/// the result of name lookup within the scope of the nested-name-specifier
/// that was computed at template definition time.
@@ -395,13 +417,16 @@ bool Sema::BuildCXXNestedNameSpecifier(S
bool EnteringContext,
CXXScopeSpec &SS,
NamedDecl *ScopeLookupResult,
- bool ErrorRecoveryLookup) {
+ bool ErrorRecoveryLookup,
+ bool *IsCorrectedToColon) {
LookupResult Found(*this, &Identifier, IdentifierLoc,
LookupNestedNameSpecifierName);
// Determine where to perform name lookup
DeclContext *LookupCtx = 0;
bool isDependent = false;
+ if (IsCorrectedToColon)
+ *IsCorrectedToColon = false;
if (!ObjectType.isNull()) {
// This nested-name-specifier occurs in a member access expression, e.g.,
// x->B::f, and we are looking into the type of the object.
@@ -416,7 +441,6 @@ bool Sema::BuildCXXNestedNameSpecifier(S
Found.setContextRange(SS.getRange());
}
-
bool ObjectTypeSearchedInScope = false;
if (LookupCtx) {
// Perform "qualified" name lookup into the declaration context we
@@ -473,17 +497,48 @@ bool Sema::BuildCXXNestedNameSpecifier(S
// Don't speculate if we're just trying to improve error recovery.
if (ErrorRecoveryLookup)
return true;
-
+
// We were not able to compute the declaration context for a dependent
// base object type or prior nested-name-specifier, so this
// nested-name-specifier refers to an unknown specialization. Just build
// a dependent nested-name-specifier.
SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
return false;
- }
-
+ }
+
// FIXME: Deal with ambiguities cleanly.
+ if (Found.empty() && !ErrorRecoveryLookup) {
+ // If identifier is not found as class-name-or-namespace-name, but is found
+ // as other entity, don't look for typos.
+ LookupResult R(*this, Found.getLookupNameInfo(), LookupOrdinaryName);
+ if (LookupCtx)
+ LookupQualifiedName(R, LookupCtx);
+ else if (S && !isDependent)
+ LookupName(R, S);
+ if (!R.empty()) {
+ // The identifier is found in ordinary lookup. If correction to colon is
+ // allowed, suggest replacement to ':'.
+ if (IsCorrectedToColon) {
+ *IsCorrectedToColon = true;
+ Diag(CCLoc, diag::err_nested_name_spec_is_not_class)
+ << &Identifier << getLangOpts().CPlusPlus
+ << FixItHint::CreateReplacement(CCLoc, ":");
+ if (NamedDecl *ND = R.getAsSingle<NamedDecl>())
+ Diag(ND->getLocation(), diag::note_declared_at);
+ return true;
+ }
+ // Replacement '::' -> ':' is not allowed, just issue respective error.
+ Diag(R.getNameLoc(), diag::err_expected_class_or_namespace)
+ << &Identifier << getLangOpts().CPlusPlus;
+ if (NamedDecl *ND = R.getAsSingle<NamedDecl>())
+ Diag(ND->getLocation(),
+ diag::note_expected_class_or_namespace_declared_here)
+ << &Identifier;
+ return true;
+ }
+ }
+
if (Found.empty() && !ErrorRecoveryLookup && !getLangOpts().MSVCCompat) {
// We haven't found anything, and we're not recovering from a
// different kind of error, so look for typos.
@@ -543,8 +598,8 @@ bool Sema::BuildCXXNestedNameSpecifier(S
!Context.hasSameType(
Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
- if (ErrorRecoveryLookup)
- return true;
+ if (ErrorRecoveryLookup)
+ return true;
Diag(IdentifierLoc,
diag::err_nested_name_member_ref_lookup_ambiguous)
@@ -558,7 +613,7 @@ bool Sema::BuildCXXNestedNameSpecifier(S
}
}
- // If we're just performing this lookup for error-recovery purposes,
+ // If we're just performing this lookup for error-recovery purposes,
// don't extend the nested-name-specifier. Just return now.
if (ErrorRecoveryLookup)
return false;
@@ -681,14 +736,17 @@ bool Sema::ActOnCXXNestedNameSpecifier(S
SourceLocation CCLoc,
ParsedType ObjectType,
bool EnteringContext,
- CXXScopeSpec &SS) {
+ CXXScopeSpec &SS,
+ bool ErrorRecoveryLookup,
+ bool *IsCorrectedToColon) {
if (SS.isInvalid())
return true;
-
+
return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc,
GetTypeFromParser(ObjectType),
EnteringContext, SS,
- /*ScopeLookupResult=*/0, false);
+ /*ScopeLookupResult=*/0, false,
+ IsCorrectedToColon);
}
bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Sun Apr 13 11:52:03 2014
@@ -584,16 +584,15 @@ Sema::NameClassification Sema::ClassifyN
CorrectionCandidateCallback *CCC) {
DeclarationNameInfo NameInfo(Name, NameLoc);
ObjCMethodDecl *CurMethod = getCurMethodDecl();
-
+
if (NextToken.is(tok::coloncolon)) {
BuildCXXNestedNameSpecifier(S, *Name, NameLoc, NextToken.getLocation(),
QualType(), false, SS, 0, false);
-
}
-
+
LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
LookupParsedName(Result, S, &SS, !CurMethod);
-
+
// Perform lookup for Objective-C instance variables (including automatically
// synthesized instance variables), if we're in an Objective-C method.
// FIXME: This lookup really, really needs to be folded in to the normal
Modified: cfe/trunk/test/Parser/recovery.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/recovery.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/test/Parser/recovery.cpp (original)
+++ cfe/trunk/test/Parser/recovery.cpp Sun Apr 13 11:52:03 2014
@@ -135,3 +135,70 @@ enum class EnumID {};
template <typename> struct TempID;
template <> struct TempID<BadType> : BadType, EnumID::Garbage; // expected-error{{use of undeclared identifier 'BadType'}}
}
+
+namespace pr15133 {
+ namespace ns {
+ const int V1 = 1; // expected-note {{declared here}}
+ }
+ struct C1 {
+ enum E1 { V2 = 2 }; // expected-note {{declared here}}
+ static const int V3 = 3; // expected-note {{declared here}}
+ };
+ enum E2 {
+ V4 = 4, // expected-note {{declared here}}
+ V6 // expected-note {{declared here}}
+ };
+ enum class EC3 { V0 = 0, V5 = 5 }; // expected-note {{declared here}}
+ void func_3();
+
+ void func_1(int x) {
+ switch(x) {
+ case 0: break;
+ case ns::V1:: break; // expected-error{{'V1' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ case C1::V2:: break; // expected-error{{'V2' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ case C1::V3:: break; // expected-error{{'V3' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ case V4:: break; // expected-error{{'V4' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ case V6:: func_3(); // expected-error{{'V6' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ }
+ }
+ void func_2(EC3 x) {
+ switch(x) {
+ case EC3::V0: break;
+ case EC3::V5:: break; // expected-error{{'V5' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ }
+ }
+
+ template<class T> struct TS1 {
+ typedef int A;
+ };
+ template<class T> void func(int x) {
+ switch(x) {
+ case TS1<T>::A:: break; // expected-error{{expected unqualified-id}}
+ }
+ };
+ void mainf() {
+ func<int>(1);
+ }
+
+ struct S {
+ static int n; // expected-note{{declared here}}
+ int nn; // expected-note 2 {{declared here}}
+ };
+
+ int func_3(int x) {
+ return x ? S::n :: 0; // expected-error{{'n' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ }
+ int func_4(int x, S &s) {
+ return x ? s.nn :: x; // expected-error{{'nn' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ }
+ int func_5(int x, S &s) {
+ return x ? s.nn :: S::n; // expected-error{{'nn' cannot appear before '::' because it is not a class, namespace, or scoped enumeration; did you mean ':'?}}
+ }
+
+ struct S2 {
+ struct S3;
+ };
+
+ struct S2 :: S3 :: public S2 { // expected-error{{'public' cannot be a part of nested name specifier; did you mean ':'?}}
+ };
+}
Modified: cfe/trunk/test/SemaCXX/nested-name-spec.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/nested-name-spec.cpp?rev=206135&r1=206134&r2=206135&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/nested-name-spec.cpp (original)
+++ cfe/trunk/test/SemaCXX/nested-name-spec.cpp Sun Apr 13 11:52:03 2014
@@ -8,13 +8,12 @@ namespace A {
static int Ag1();
static int Ag2();
};
- int ax;
+ int ax; // expected-note {{'ax' declared here}}
void Af();
}
A:: ; // expected-error {{expected unqualified-id}}
-// FIXME: there is a member 'ax'; it's just not a class.
-::A::ax::undef ex3; // expected-error {{no member named 'ax'}}
+::A::ax::undef ex3; // expected-error {{'ax' is not a class, namespace, or scoped enumeration}}
A::undef1::undef2 ex4; // expected-error {{no member named 'undef1'}}
int A::C::Ag1() { return 0; }
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