Files
pycapnp/vendor/capnproto/src/capnp/compiler/resolver.h
2026-09-21 20:05:46 -07:00

133 lines
5.9 KiB
C++

// Copyright (c) 2013-2020 Sandstorm Development Group, Inc. and contributors
// Licensed under the MIT License:
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#pragma once
#include <capnp/compiler/grammar.capnp.h>
#include <capnp/schema.capnp.h>
#include <capnp/schema.h>
#include <kj/one-of.h>
CAPNP_BEGIN_HEADER
namespace capnp {
namespace compiler {
class Resolver {
// Callback class used to find other nodes relative to some existing node.
//
// `Resolver` is used when compiling one declaration requires inspecting the compiled versions
// of other declarations it depends on. For example, if struct type Foo contains a field of type
// Bar, and specifies a default value for that field, then to parse that default value we need
// the compiled version of `Bar`. Or, more commonly, if a struct type Foo refers to some other
// type `Bar.Baz`, this requires doing a lookup that depends on at least partial compilation of
// `Bar`, in order to discover its nested type `Baz`.
//
// Note that declarations are often compiled just-in-time the first time they are resolved. So,
// the methods of Resolver may recurse back into other parts of the compiler. It must detect when
// a dependency cycle occurs and report an error in order to prevent an infinite loop.
public:
struct ResolvedDecl {
// Information about a resolved declaration.
uint64_t id;
// Type ID / node ID of the resolved declaration.
uint genericParamCount;
// If non-zero, the declaration is a generic with the given number of parameters.
uint64_t scopeId;
// The ID of the parent scope of this declaration.
Declaration::Which kind;
// What basic kind of declaration is this? E.g. struct, interface, const, etc.
Resolver* resolver;
// `Resolver` instance that can be used to further resolve other declarations relative to this
// one.
kj::Maybe<schema::Brand::Reader> brand;
// If present, then it is necessary to replace the brand scope with the given brand before
// using the target type. This happens when the decl resolved to an alias; all other fields
// of `ResolvedDecl` refer to the target of the alias, except for `scopeId` which is the
// scope that contained the alias.
};
struct ResolvedParameter {
uint64_t id; // ID of the node declaring the parameter.
uint index; // Index of the parameter.
};
typedef kj::OneOf<ResolvedDecl, ResolvedParameter> ResolveResult;
virtual kj::Maybe<ResolveResult> resolve(kj::StringPtr name) = 0;
// Look up the given name, relative to this node, and return basic information about the
// target.
virtual kj::Maybe<ResolveResult> resolveMember(kj::StringPtr name) = 0;
// Look up a member of this node.
virtual ResolvedDecl resolveBuiltin(Declaration::Which which) = 0;
virtual ResolvedDecl resolveId(uint64_t id) = 0;
virtual kj::Maybe<ResolvedDecl> getParent() = 0;
// Returns the parent of this scope, or null if this is the top scope.
virtual ResolvedDecl getTopScope() = 0;
// Get the top-level scope containing this node.
virtual kj::Maybe<Schema> resolveBootstrapSchema(uint64_t id, schema::Brand::Reader brand) = 0;
// Get the schema for the given ID. If a schema is returned, it must be safe to traverse its
// dependencies via the Schema API. A schema that is only at the bootstrap stage is
// acceptable.
//
// Throws an exception if the id is not one that was found by calling resolve() or by
// traversing other schemas. Returns null if the ID is recognized, but the corresponding
// schema node failed to be built for reasons that were already reported.
virtual kj::Maybe<schema::Node::Reader> resolveFinalSchema(uint64_t id) = 0;
// Get the final schema for the given ID. A bootstrap schema is not acceptable. A raw
// node reader is returned rather than a Schema object because using a Schema object built
// by the final schema loader could trigger lazy initialization of dependencies which could
// lead to a cycle and deadlock.
//
// Throws an exception if the id is not one that was found by calling resolve() or by
// traversing other schemas. Returns null if the ID is recognized, but the corresponding
// schema node failed to be built for reasons that were already reported.
virtual kj::Maybe<ResolvedDecl> resolveImport(kj::StringPtr name) = 0;
// Get the ID of an imported file given the import path.
virtual kj::Maybe<kj::Array<const byte>> readEmbed(kj::StringPtr name) = 0;
// Read and return the contents of a file for an `embed` expression.
virtual kj::Maybe<Type> resolveBootstrapType(schema::Type::Reader type, Schema scope) = 0;
// Compile a schema::Type into a Type whose dependencies may safely be traversed via the schema
// API. These dependencies may have only bootstrap schemas. Returns null if the type could not
// be constructed due to already-reported errors.
};
} // namespace compiler
} // namespace capnp
CAPNP_END_HEADER