[Concepts] Concept definitions (D40381)
First in a series of patches to land C++2a Concepts support.
This patch adds AST and parsing support for concept-declarations.
llvm-svn: 365699
diff --git a/clang/lib/Parse/ParseTemplate.cpp b/clang/lib/Parse/ParseTemplate.cpp
index 78e0c04..6ae75ed 100644
--- a/clang/lib/Parse/ParseTemplate.cpp
+++ b/clang/lib/Parse/ParseTemplate.cpp
@@ -49,6 +49,15 @@
/// template-declaration: [C++ temp]
/// 'export'[opt] 'template' '<' template-parameter-list '>' declaration
///
+/// template-declaration: [C++2a]
+/// template-head declaration
+/// template-head concept-definition
+///
+/// TODO: requires-clause
+/// template-head: [C++2a]
+/// 'template' '<' template-parameter-list '>'
+/// requires-clause[opt]
+///
/// explicit-specialization: [ C++ temp.expl.spec]
/// 'template' '<' '>' declaration
Decl *Parser::ParseTemplateDeclarationOrSpecialization(
@@ -142,6 +151,12 @@
ParseScopeFlags TemplateScopeFlags(this, NewFlags, isSpecialization);
// Parse the actual template declaration.
+ if (Tok.is(tok::kw_concept))
+ return ParseConceptDefinition(
+ ParsedTemplateInfo(&ParamLists, isSpecialization,
+ LastParamListWasEmpty),
+ DeclEnd);
+
return ParseSingleDeclarationAfterTemplate(
Context,
ParsedTemplateInfo(&ParamLists, isSpecialization, LastParamListWasEmpty),
@@ -315,6 +330,85 @@
return ThisDecl;
}
+/// \brief Parse a single declaration that declares a concept.
+///
+/// \param DeclEnd will receive the source location of the last token
+/// within this declaration.
+///
+/// \returns the new declaration.
+Decl *
+Parser::ParseConceptDefinition(const ParsedTemplateInfo &TemplateInfo,
+ SourceLocation &DeclEnd) {
+ assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
+ "Template information required");
+ assert(Tok.is(tok::kw_concept) &&
+ "ParseConceptDefinition must be called when at a 'concept' keyword");
+
+ ConsumeToken(); // Consume 'concept'
+
+ SourceLocation BoolKWLoc;
+ if (TryConsumeToken(tok::kw_bool, BoolKWLoc))
+ Diag(Tok.getLocation(), diag::ext_concept_legacy_bool_keyword) <<
+ FixItHint::CreateRemoval(SourceLocation(BoolKWLoc));
+
+ DiagnoseAndSkipCXX11Attributes();
+
+ CXXScopeSpec SS;
+ if (ParseOptionalCXXScopeSpecifier(SS, ParsedType(),
+ /*EnteringContext=*/false, /*MayBePseudoDestructor=*/nullptr,
+ /*IsTypename=*/false, /*LastII=*/nullptr, /*OnlyNamespace=*/true) ||
+ SS.isInvalid()) {
+ SkipUntil(tok::semi);
+ return nullptr;
+ }
+
+ if (SS.isNotEmpty())
+ Diag(SS.getBeginLoc(),
+ diag::err_concept_definition_not_identifier);
+
+ UnqualifiedId Result;
+ if (ParseUnqualifiedId(SS, /*EnteringContext=*/false,
+ /*AllowDestructorName=*/false,
+ /*AllowConstructorName=*/false,
+ /*AllowDeductionGuide=*/false,
+ /*ObjectType=*/ParsedType(), /*TemplateKWLoc=*/nullptr,
+ Result)) {
+ SkipUntil(tok::semi);
+ return nullptr;
+ }
+
+ if (Result.getKind() != UnqualifiedIdKind::IK_Identifier) {
+ Diag(Result.getBeginLoc(), diag::err_concept_definition_not_identifier);
+ SkipUntil(tok::semi);
+ return nullptr;
+ }
+
+ IdentifierInfo *Id = Result.Identifier;
+ SourceLocation IdLoc = Result.getBeginLoc();
+
+ DiagnoseAndSkipCXX11Attributes();
+
+ if (!TryConsumeToken(tok::equal)) {
+ Diag(Tok.getLocation(), diag::err_expected) << tok::equal;
+ SkipUntil(tok::semi);
+ return nullptr;
+ }
+
+ ExprResult ConstraintExprResult =
+ Actions.CorrectDelayedTyposInExpr(ParseConstraintExpression());
+ if (ConstraintExprResult.isInvalid()) {
+ SkipUntil(tok::semi);
+ return nullptr;
+ }
+
+ DeclEnd = Tok.getLocation();
+ ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
+ Expr *ConstraintExpr = ConstraintExprResult.get();
+ return Actions.ActOnConceptDefinition(getCurScope(),
+ *TemplateInfo.TemplateParams,
+ Id, IdLoc, ConstraintExpr);
+}
+
/// ParseTemplateParameters - Parses a template-parameter-list enclosed in
/// angle brackets. Depth is the depth of this template-parameter-list, which
/// is the number of template headers directly enclosing this template header.