comparison win32-mingw/include/capnp/raw-schema.h @ 64:eccd51b72864

Update Win32 capnp builds to v0.6

+// Copyright (c) 2013-2014 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.
+
+#ifndef CAPNP_RAW_SCHEMA_H_
+#define CAPNP_RAW_SCHEMA_H_
+
+#if defined(__GNUC__) && !defined(CAPNP_HEADER_WARNINGS)
+#pragma GCC system_header
+#endif
+
+#include "common.h"  // for uint and friends
+
+#if _MSC_VER
+#include <atomic>
+#endif
+
+namespace capnp {
+namespace _ {  // private
+
+struct RawSchema;
+
+struct RawBrandedSchema {
+  // Represents a combination of a schema and bindings for its generic parameters.
+  //
+  // Note that while we generate one `RawSchema` per type, we generate a `RawBrandedSchema` for
+  // every _instance_ of a generic type -- or, at least, every instance that is actually used. For
+  // generated-code types, we use template magic to initialize these.
+
+  const RawSchema* generic;
+  // Generic type which we're branding.
+
+  struct Binding {
+    uint8_t which;       // Numeric value of one of schema::Type::Which.
+
+    bool isImplicitParameter;
+    // For AnyPointer, true if it's an implicit method parameter.
+
+    uint16_t listDepth;  // Number of times to wrap the base type in List().
+
+    uint16_t paramIndex;
+    // For AnyPointer. If it's a type parameter (scopeId is non-zero) or it's an implicit parameter
+    // (isImplicitParameter is true), then this is the parameter index. Otherwise this is a numeric
+    // value of one of schema::Type::AnyPointer::Unconstrained::Which.
+
+    union {
+      const RawBrandedSchema* schema;  // for struct, enum, interface
+      uint64_t scopeId;                // for AnyPointer, if it's a type parameter
+    };
+
+    Binding() = default;
+    inline constexpr Binding(uint8_t which, uint16_t listDepth, const RawBrandedSchema* schema)
+        : which(which), isImplicitParameter(false), listDepth(listDepth), paramIndex(0),
+          schema(schema) {}
+    inline constexpr Binding(uint8_t which, uint16_t listDepth,
+                             uint64_t scopeId, uint16_t paramIndex)
+        : which(which), isImplicitParameter(false), listDepth(listDepth), paramIndex(paramIndex),
+          scopeId(scopeId) {}
+    inline constexpr Binding(uint8_t which, uint16_t listDepth, uint16_t implicitParamIndex)
+        : which(which), isImplicitParameter(true), listDepth(listDepth),
+          paramIndex(implicitParamIndex), scopeId(0) {}
+  };
+
+  struct Scope {
+    uint64_t typeId;
+    // Type ID whose parameters are being bound.
+
+    const Binding* bindings;
+    uint bindingCount;
+    // Bindings for those parameters.
+
+    bool isUnbound;
+    // This scope is unbound, in the sense of SchemaLoader::getUnbound().
+  };
+
+  const Scope* scopes;
+  // Array of enclosing scopes for which generic variables have been bound, sorted by type ID.
+
+  struct Dependency {
+    uint location;
+    const RawBrandedSchema* schema;
+  };
+
+  const Dependency* dependencies;
+  // Map of branded schemas for dependencies of this type, given our brand. Only dependencies that
+  // are branded are included in this map; if a dependency is missing, use its `defaultBrand`.
+
+  uint32_t scopeCount;
+  uint32_t dependencyCount;
+
+  enum class DepKind {
+    // Component of a Dependency::location. Specifies what sort of dependency this is.
+
+    INVALID,
+    // Mostly defined to ensure that zero is not a valid location.
+
+    FIELD,
+    // Binding needed for a field's type. The index is the field index (NOT ordinal!).
+
+    METHOD_PARAMS,
+    // Bindings needed for a method's params type. The index is the method number.
+
+    METHOD_RESULTS,
+    // Bindings needed for a method's results type. The index is the method ordinal.
+
+    SUPERCLASS,
+    // Bindings needed for a superclass type. The index is the superclass's index in the
+    // "extends" list.
+
+    CONST_TYPE
+    // Bindings needed for the type of a constant. The index is zero.
+  };
+
+  static inline uint makeDepLocation(DepKind kind, uint index) {
+    // Make a number representing the location of a particular dependency within its parent
+    // schema.
+
+    return (static_cast<uint>(kind) << 24) | index;
+  }
+
+  class Initializer {
+  public:
+    virtual void init(const RawBrandedSchema* generic) const = 0;
+  };
+
+  const Initializer* lazyInitializer;
+  // Lazy initializer, invoked by ensureInitialized().
+
+  inline void ensureInitialized() const {
+    // Lazy initialization support.  Invoke to ensure that initialization has taken place.  This
+    // is required in particular when traversing the dependency list.  RawSchemas for compiled-in
+    // types are always initialized; only dynamically-loaded schemas may be lazy.
+
+#if __GNUC__
+    const Initializer* i = __atomic_load_n(&lazyInitializer, __ATOMIC_ACQUIRE);
+#elif _MSC_VER
+    const Initializer* i = *static_cast<Initializer const* const volatile*>(&lazyInitializer);
+    std::atomic_thread_fence(std::memory_order_acquire);
+#else
+#error "Platform not supported"
+#endif
+    if (i != nullptr) i->init(this);
+  }
+
+  inline bool isUnbound() const;
+  // Checks if this schema is the result of calling SchemaLoader::getUnbound(), in which case
+  // binding lookups need to be handled specially.
+};
+
+struct RawSchema {
+  // The generated code defines a constant RawSchema for every compiled declaration.
+  //
+  // This is an internal structure which could change in the future.
+
+  uint64_t id;
+
+  const word* encodedNode;
+  // Encoded SchemaNode, readable via readMessageUnchecked<schema::Node>(encodedNode).
+
+  uint32_t encodedSize;
+  // Size of encodedNode, in words.
+
+  const RawSchema* const* dependencies;
+  // Pointers to other types on which this one depends, sorted by ID.  The schemas in this table
+  // may be uninitialized -- you must call ensureInitialized() on the one you wish to use before
+  // using it.
+  //
+  // TODO(someday):  Make this a hashtable.
+
+  const uint16_t* membersByName;
+  // Indexes of members sorted by name.  Used to implement name lookup.
+  // TODO(someday):  Make this a hashtable.
+
+  uint32_t dependencyCount;
+  uint32_t memberCount;
+  // Sizes of above tables.
+
+  const uint16_t* membersByDiscriminant;
+  // List of all member indexes ordered by discriminant value.  Those which don't have a
+  // discriminant value are listed at the end, in order by ordinal.
+
+  const RawSchema* canCastTo;
+  // Points to the RawSchema of a compiled-in type to which it is safe to cast any DynamicValue
+  // with this schema.  This is null for all compiled-in types; it is only set by SchemaLoader on
+  // dynamically-loaded types.
+
+  class Initializer {
+  public:
+    virtual void init(const RawSchema* schema) const = 0;
+  };
+
+  const Initializer* lazyInitializer;
+  // Lazy initializer, invoked by ensureInitialized().
+
+  inline void ensureInitialized() const {
+    // Lazy initialization support.  Invoke to ensure that initialization has taken place.  This
+    // is required in particular when traversing the dependency list.  RawSchemas for compiled-in
+    // types are always initialized; only dynamically-loaded schemas may be lazy.
+
+#if __GNUC__
+    const Initializer* i = __atomic_load_n(&lazyInitializer, __ATOMIC_ACQUIRE);
+#elif _MSC_VER
+    const Initializer* i = *static_cast<Initializer const* const volatile*>(&lazyInitializer);
+    std::atomic_thread_fence(std::memory_order_acquire);
+#else
+#error "Platform not supported"
+#endif
+    if (i != nullptr) i->init(this);
+  }
+
+  RawBrandedSchema defaultBrand;
+  // Specifies the brand to use for this schema if no generic parameters have been bound to
+  // anything. Generally, in the default brand, all generic parameters are treated as if they were
+  // bound to `AnyPointer`.
+};
+
+inline bool RawBrandedSchema::isUnbound() const {
+  // The unbound schema is the only one that has no scopes but is not the default schema.
+  return scopeCount == 0 && this != &generic->defaultBrand;
+}
+
+}  // namespace _ (private)
+}  // namespace capnp
+
+#endif  // CAPNP_RAW_SCHEMA_H_