feat: support concepts and constraints (#649)

Author: sdkrystian

include/mrdocs/Metadata.hpp

@@ -18,6 +18,7 @@
 // metadata extracted from AST
 
 #include <mrdocs/Metadata/Alias.hpp>
+#include <mrdocs/Metadata/Concept.hpp>
 #include <mrdocs/Metadata/Enum.hpp>
 #include <mrdocs/Metadata/Enumerator.hpp>
 #include <mrdocs/Metadata/Expression.hpp>

include/mrdocs/Metadata/Concept.hpp

@@ -0,0 +1,47 @@
+//
+// Licensed under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// Copyright (c) 2024 Krystian Stasiowski ([email protected])
+//
+// Official repository: https://github.com/cppalliance/mrdocs
+//
+
+#ifndef MRDOCS_API_METADATA_CONCEPT_HPP
+#define MRDOCS_API_METADATA_CONCEPT_HPP
+
+#include <mrdocs/Platform.hpp>
+#include <mrdocs/Metadata/Info.hpp>
+#include <mrdocs/Metadata/Expression.hpp>
+#include <mrdocs/Metadata/Source.hpp>
+
+namespace clang {
+namespace mrdocs {
+
+/** Info for concepts.
+*/
+struct ConceptInfo
+    : InfoCommonBase<InfoKind::Concept>
+    , SourceInfo
+{
+    /** The concepts template parameters
+    */
+    std::unique_ptr<TemplateInfo> Template;
+
+    /** The concepts constraint-expression
+    */
+    ExprInfo Constraint;
+
+    //--------------------------------------------
+
+    explicit ConceptInfo(SymbolID ID) noexcept
+        : InfoCommonBase(ID)
+    {
+    }
+};
+
+} // mrdocs
+} // clang
+
+#endif

include/mrdocs/Metadata/Function.hpp

@@ -159,6 +159,8 @@ struct FunctionInfo
 
     ExplicitInfo Explicit;
 
+    ExprInfo Requires;
+
     //--------------------------------------------
 
     explicit FunctionInfo(SymbolID ID) noexcept

include/mrdocs/Metadata/InfoNodes.inc

@@ -77,6 +77,7 @@ INFO(Enumerator,     Enumerators,     ENUMERATOR,     enumerator,     enumerator
 INFO(Guide,          Guides,          GUIDE,          guide,          guides,          The symbol is a deduction guide)
 INFO(Alias,          Aliases,         ALIAS,          alias,          aliases,         The symbol is a namespace alias)
 INFO(Using,          Usings,          USING,          using,          usings,          The symbol is a using declaration)
+INFO(Concept,        Concepts,        CONCEPT,        concept,        concepts,        The symbol is a concept)
 
 #ifdef INFO_PASCAL
 #undef INFO_PASCAL

include/mrdocs/Metadata/Template.hpp

@@ -207,6 +207,9 @@ struct TypeTParam
 {
     /** Keyword (class/typename) the parameter uses */
     TParamKeyKind KeyKind = TParamKeyKind::Class;
+
+    /** The type-constraint for the parameter, if any. */
+    std::unique_ptr<NameInfo> Constraint;
 };
 
 struct NonTypeTParam
@@ -284,6 +287,10 @@ struct TemplateInfo
     std::vector<std::unique_ptr<TParam>> Params;
     std::vector<std::unique_ptr<TArg>> Args;
 
+    /** The requires-clause for the template parameter list, if any.
+    */
+    ExprInfo Requires;
+
     /** Primary template ID for partial and explicit specializations.
     */
     SymbolID Primary = SymbolID::invalid;

include/mrdocs/Metadata/Type.hpp

@@ -26,7 +26,7 @@
 namespace clang {
 namespace mrdocs {
 
-enum QualifierKind : int
+enum QualifierKind
 {
     None,
     Const,
@@ -39,6 +39,7 @@ enum class TypeKind
 {
     Named = 1, // for bitstream
     Decltype,
+    Auto,
     LValueReference,
     RValueReference,
     Pointer,
@@ -49,6 +50,14 @@ enum class TypeKind
 
 MRDOCS_DECL dom::String toString(TypeKind kind) noexcept;
 
+enum class AutoKind
+{
+    Auto,
+    DecltypeAuto
+};
+
+MRDOCS_DECL dom::String toString(AutoKind kind) noexcept;
+
 struct TypeInfo
 {
     /** The kind of TypeInfo this is
@@ -63,6 +72,7 @@ struct TypeInfo
 
     constexpr bool isNamed()           const noexcept { return Kind == TypeKind::Named; }
     constexpr bool isDecltype()        const noexcept { return Kind == TypeKind::Decltype; }
+    constexpr bool isAuto()            const noexcept { return Kind == TypeKind::Auto; }
     constexpr bool isLValueReference() const noexcept { return Kind == TypeKind::LValueReference; }
     constexpr bool isRValueReference() const noexcept { return Kind == TypeKind::RValueReference; }
     constexpr bool isPointer()         const noexcept { return Kind == TypeKind::Pointer; }
@@ -100,6 +110,7 @@ struct IsType : TypeInfo
 
     static constexpr bool isNamed()           noexcept { return K == TypeKind::Named; }
     static constexpr bool isDecltype()        noexcept { return K == TypeKind::Decltype; }
+    static constexpr bool isAuto()            noexcept { return K == TypeKind::Auto; }
     static constexpr bool isLValueReference() noexcept { return K == TypeKind::LValueReference; }
     static constexpr bool isRValueReference() noexcept { return K == TypeKind::RValueReference; }
     static constexpr bool isPointer()         noexcept { return K == TypeKind::Pointer; }
@@ -129,6 +140,14 @@ struct DecltypeTypeInfo
     ExprInfo Operand;
 };
 
+struct AutoTypeInfo
+    : IsType<TypeKind::Auto>
+{
+    QualifierKind CVQualifiers = QualifierKind::None;
+    AutoKind Keyword = AutoKind::Auto;
+    std::unique_ptr<NameInfo> Constraint;
+};
+
 struct LValueReferenceTypeInfo
     : IsType<TypeKind::LValueReference>
 {
@@ -226,6 +245,10 @@ visit(
         return f(static_cast<add_cv_from_t<
             TypeTy, DecltypeTypeInfo>&>(II),
                 std::forward<Args>(args)...);
+    case TypeKind::Auto:
+        return f(static_cast<add_cv_from_t<
+            TypeTy, AutoTypeInfo>&>(II),
+                std::forward<Args>(args)...);
     case TypeKind::LValueReference:
         return f(static_cast<add_cv_from_t<
             TypeTy, LValueReferenceTypeInfo>&>(II),

mrdocs.rnc

@@ -79,6 +79,7 @@ grammar
             attribute class { "constructor"|"destructor"|"conversion" } ?,
             attribute exception-spec { text } ?,
             attribute explicit-spec { text } ?,
+            attribute requires { text } ?,
             Location *,
             (
                 Attr * |
@@ -246,6 +247,19 @@ grammar
 
     #---------------------------------------------
 
+    Concept =
+        element concept
+        {
+            Name,
+            Access ?,
+            ID,
+            Location *,
+            Javadoc ?,
+            attribute constraint { text }
+        }
+
+    #---------------------------------------------
+
     Symbol =
     (
         attribute Tag { text },
@@ -263,6 +277,7 @@ grammar
         element template
         {
             attribute class { "explicit"|"partial" } ?,
+            attribute requires { text } ?,
             ID ?,
             TemplateParam *,
             TemplateArg *,
@@ -272,6 +287,7 @@ grammar
                 Typedef   |
                 Variable  |
                 Guide     |
+                Concept   |
                 Template
             )
         }
@@ -337,6 +353,7 @@ grammar
             Template       |
             Alias          |
             Using          |
+            Concept        |
             Specialization
         )*
 
@@ -436,6 +453,7 @@ grammar
             {
                 "named" |
                 "decltype" |
+                "auto" |
                 "lvalue-reference" |
                 "rvalue-reference" |
                 "pointer" |
@@ -453,6 +471,8 @@ grammar
             attribute exception-spec { text } ?,
             attribute bounds { text } ?,
             attribute operand { text } ?,
+            attribute constraint { text } ?,
+            attribute keyword { text } ?,
             TypeInfo *
         }
     )

share/mrdocs/addons/generator/asciidoc/partials/declarator-before.adoc.hbs

@@ -5,6 +5,7 @@
 {{#if element-type~}}{{~>declarator-before element-type nolink=nolink~}}{{/if~}}
 {{#if return-type~}}{{~>declarator-before return-type nolink=nolink~}}{{/if~}}
 {{#if (eq kind "named")}}{{>name-info name nolink=nolink}}{{/if~}}
+{{#if (eq kind "auto")}}{{#if constraint}}{{>name-info constraint nolink=nolink}} {{/if~}}{{keyword}}{{/if~}}
 {{#if cv-qualifiers~}}
     {{#if pointee-type}} {{cv-qualifiers}}{{else}} {{cv-qualifiers}}{{/if~}}
 {{/if~}}

share/mrdocs/addons/generator/asciidoc/partials/signature/concept.adoc.hbs

@@ -0,0 +1,3 @@
+{{>template-head symbol.template}}
+
+concept {{>declarator-id symbol}} = {{symbol.constraint}}

share/mrdocs/addons/generator/asciidoc/partials/signature/function.adoc.hbs

@@ -23,6 +23,7 @@
 {{#if symbol.refQualifier}} {{symbol.refQualifier}}{{/if~}}
 {{#if symbol.exceptionSpec}} {{symbol.exceptionSpec}}{{/if~}}
 {{#if (eq symbol.class "normal")}}{{>declarator-after symbol.return}}{{/if~}}
+{{#if symbol.requires}} requires {{symbol.requires}}{{/if~}}
 {{#if symbol.hasOverrideAttr}} override{{/if~}}
 {{#if symbol.isFinal}} final{{/if~}}
 {{#if symbol.isPure}} = 0{{/if~}}