r212957 - Improve error recovery around colon.
Serge Pavlov
sepavloff at gmail.com
Mon Jul 14 09:42:21 PDT 2014
Author: sepavloff
Date: Mon Jul 14 11:42:20 2014
New Revision: 212957
URL: http://llvm.org/viewvc/llvm-project?rev=212957&view=rev
Log:
Improve error recovery around colon.
Recognize additional cases, when '::' is mistyped as ':'.
This is a fix to RP18587 - colons have too much protection in member-declarations.
Differential Revision: http://reviews.llvm.org/D3653
Modified:
cfe/trunk/lib/Parse/ParseDecl.cpp
cfe/trunk/lib/Parse/ParseDeclCXX.cpp
cfe/trunk/test/SemaCXX/enum-bitfield.cpp
cfe/trunk/test/SemaCXX/nested-name-spec.cpp
Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=212957&r1=212956&r2=212957&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
+++ cfe/trunk/lib/Parse/ParseDecl.cpp Mon Jul 14 11:42:20 2014
@@ -2715,24 +2715,23 @@ void Parser::ParseDeclarationSpecifiers(
// typedef-name
case tok::kw_decltype:
case tok::identifier: {
+ // This identifier can only be a typedef name if we haven't already seen
+ // a type-specifier. Without this check we misparse:
+ // typedef int X; struct Y { short X; }; as 'short int'.
+ if (DS.hasTypeSpecifier())
+ goto DoneWithDeclSpec;
+
// In C++, check to see if this is a scope specifier like foo::bar::, if
// so handle it as such. This is important for ctor parsing.
if (getLangOpts().CPlusPlus) {
if (TryAnnotateCXXScopeToken(EnteringContext)) {
- if (!DS.hasTypeSpecifier())
- DS.SetTypeSpecError();
+ DS.SetTypeSpecError();
goto DoneWithDeclSpec;
}
if (!Tok.is(tok::identifier))
continue;
}
- // This identifier can only be a typedef name if we haven't already seen
- // a type-specifier. Without this check we misparse:
- // typedef int X; struct Y { short X; }; as 'short int'.
- if (DS.hasTypeSpecifier())
- goto DoneWithDeclSpec;
-
// Check for need to substitute AltiVec keyword tokens.
if (TryAltiVecToken(DS, Loc, PrevSpec, DiagID, isInvalid))
break;
@@ -4529,7 +4528,9 @@ void Parser::ParseDeclaratorInternal(Dec
// Member pointers get special handling, since there's no place for the
// scope spec in the generic path below.
if (getLangOpts().CPlusPlus &&
- (Tok.is(tok::coloncolon) || Tok.is(tok::identifier) ||
+ (Tok.is(tok::coloncolon) ||
+ (Tok.is(tok::identifier) &&
+ (NextToken().is(tok::coloncolon) || NextToken().is(tok::less))) ||
Tok.is(tok::annot_cxxscope))) {
bool EnteringContext = D.getContext() == Declarator::FileContext ||
D.getContext() == Declarator::MemberContext;
@@ -4722,6 +4723,11 @@ void Parser::ParseDirectDeclarator(Decla
DeclaratorScopeObj DeclScopeObj(*this, D.getCXXScopeSpec());
if (getLangOpts().CPlusPlus && D.mayHaveIdentifier()) {
+ // Don't parse FOO:BAR as if it were a typo for FOO::BAR inside a class, in
+ // this context it is a bitfield.
+ ColonProtectionRAIIObject X(*this,
+ D.getContext() == Declarator::MemberContext);
+
// ParseDeclaratorInternal might already have parsed the scope.
if (D.getCXXScopeSpec().isEmpty()) {
bool EnteringContext = D.getContext() == Declarator::FileContext ||
Modified: cfe/trunk/lib/Parse/ParseDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDeclCXX.cpp?rev=212957&r1=212956&r2=212957&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseDeclCXX.cpp (original)
+++ cfe/trunk/lib/Parse/ParseDeclCXX.cpp Mon Jul 14 11:42:20 2014
@@ -1239,7 +1239,8 @@ void Parser::ParseClassSpecifier(tok::To
// Parse the (optional) nested-name-specifier.
CXXScopeSpec &SS = DS.getTypeSpecScope();
if (getLangOpts().CPlusPlus) {
- // "FOO : BAR" is not a potential typo for "FOO::BAR".
+ // "FOO : BAR" is not a potential typo for "FOO::BAR". In this context it
+ // is a base-specifier-list.
ColonProtectionRAIIObject X(*this);
if (ParseOptionalCXXScopeSpecifier(SS, ParsedType(), EnteringContext))
@@ -1926,14 +1927,8 @@ void Parser::ParseCXXMemberDeclaratorBef
// declarator pure-specifier[opt]
// declarator brace-or-equal-initializer[opt]
// identifier[opt] ':' constant-expression
- if (Tok.isNot(tok::colon)) {
- // Don't parse FOO:BAR as if it were a typo for FOO::BAR, in this context it
- // is a bitfield.
- // FIXME: This should only apply when parsing the id-expression (see
- // PR18587).
- ColonProtectionRAIIObject X(*this);
+ if (Tok.isNot(tok::colon))
ParseDeclarator(DeclaratorInfo);
- }
if (!DeclaratorInfo.isFunctionDeclarator() && TryConsumeToken(tok::colon)) {
BitfieldSize = ParseConstantExpression();
@@ -2015,6 +2010,14 @@ void Parser::ParseCXXClassMemberDeclarat
return;
}
+ // Turn on colon protection early, while parsing declspec, although there is
+ // nothing to protect there. It prevents from false errors if error recovery
+ // incorrectly determines where the declspec ends, as in the example:
+ // struct A { enum class B { C }; };
+ // const int C = 4;
+ // struct D { A::B : C; };
+ ColonProtectionRAIIObject X(*this);
+
// Access declarations.
bool MalformedTypeSpec = false;
if (!TemplateInfo.Kind &&
@@ -2128,13 +2131,11 @@ void Parser::ParseCXXClassMemberDeclarat
if (MalformedTypeSpec)
DS.SetTypeSpecError();
- {
- // Don't parse FOO:BAR as if it were a typo for FOO::BAR, in this context it
- // is a bitfield.
- ColonProtectionRAIIObject X(*this);
- ParseDeclarationSpecifiers(DS, TemplateInfo, AS, DSC_class,
- &CommonLateParsedAttrs);
- }
+ ParseDeclarationSpecifiers(DS, TemplateInfo, AS, DSC_class,
+ &CommonLateParsedAttrs);
+
+ // Turn off colon protection that was set for declspec.
+ X.restore();
// If we had a free-standing type definition with a missing semicolon, we
// may get this far before the problem becomes obvious.
Modified: cfe/trunk/test/SemaCXX/enum-bitfield.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/enum-bitfield.cpp?rev=212957&r1=212956&r2=212957&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/enum-bitfield.cpp (original)
+++ cfe/trunk/test/SemaCXX/enum-bitfield.cpp Mon Jul 14 11:42:20 2014
@@ -16,3 +16,15 @@ struct Y {
enum E : int(2);
enum E : Z(); // expected-error{{integral constant expression must have integral or unscoped enumeration type, not 'Z'}}
};
+
+namespace pr18587 {
+struct A {
+ enum class B {
+ C
+ };
+};
+const int C = 4;
+struct D {
+ A::B : C;
+};
+}
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=212957&r1=212956&r2=212957&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/nested-name-spec.cpp (original)
+++ cfe/trunk/test/SemaCXX/nested-name-spec.cpp Mon Jul 14 11:42:20 2014
@@ -311,3 +311,102 @@ namespace N {
namespace TypedefNamespace { typedef int F; };
TypedefNamespace::F::NonexistentName BadNNSWithCXXScopeSpec; // expected-error {{'F' (aka 'int') is not a class, namespace, or scoped enumeration}}
+
+namespace PR18587 {
+
+struct C1 {
+ int a, b, c;
+ typedef int C2;
+ struct B1 {
+ struct B2 {
+ int a, b, c;
+ };
+ };
+};
+struct C2 { static const unsigned N1 = 1; };
+struct B1 {
+ enum E1 { B2 = 2 };
+ static const int B3 = 3;
+};
+const int N1 = 2;
+
+// Function declarators
+struct S1a { int f(C1::C2); };
+struct S1b { int f(C1:C2); }; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+
+struct S2a {
+ C1::C2 f(C1::C2);
+};
+struct S2c {
+ C1::C2 f(C1:C2); // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+
+struct S3a {
+ int f(C1::C2), C2 : N1;
+ int g : B1::B2;
+};
+struct S3b {
+ int g : B1:B2; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+
+// Inside square brackets
+struct S4a {
+ int f[C2::N1];
+};
+struct S4b {
+ int f[C2:N1]; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+
+struct S5a {
+ int f(int xx[B1::B3 ? C2::N1 : B1::B2]);
+};
+struct S5b {
+ int f(int xx[B1::B3 ? C2::N1 : B1:B2]); // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+struct S5c {
+ int f(int xx[B1:B3 ? C2::N1 : B1::B2]); // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+
+// Bit fields
+struct S6a {
+ C1::C2 m1 : B1::B2;
+};
+struct S6c {
+ C1::C2 m1 : B1:B2; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+struct S6d {
+ int C2:N1;
+};
+struct S6e {
+ static const int N = 3;
+ B1::E1 : N;
+};
+struct S6g {
+ C1::C2 : B1:B2; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+ B1::E1 : B1:B2; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+
+// Template parameters
+template <int N> struct T1 {
+ int a,b,c;
+ static const unsigned N1 = N;
+ typedef unsigned C1;
+};
+T1<C2::N1> var_1a;
+T1<C2:N1> var_1b; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+template<int N> int F() {}
+int (*X1)() = (B1::B2 ? F<1> : F<2>);
+int (*X2)() = (B1:B2 ? F<1> : F<2>); // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+
+// Bit fields + templates
+struct S7a {
+ T1<B1::B2>::C1 m1 : T1<B1::B2>::N1;
+};
+struct S7b {
+ T1<B1:B2>::C1 m1 : T1<B1::B2>::N1; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+struct S7c {
+ T1<B1::B2>::C1 m1 : T1<B1:B2>::N1; // expected-error{{unexpected ':' in nested name specifier; did you mean '::'?}}
+};
+
+}
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