src/tint/resolver/dependency_graph.h - tint - Git at Google

 // Copyright 2021 The Tint Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #ifndef SRC_TINT_RESOLVER_DEPENDENCY_GRAPH_H_
 #define SRC_TINT_RESOLVER_DEPENDENCY_GRAPH_H_

 #include <string>
 #include <vector>

 #include "src/tint/ast/module.h"
 #include "src/tint/builtin/access.h"
 #include "src/tint/builtin/builtin.h"
 #include "src/tint/builtin/builtin_value.h"
 #include "src/tint/builtin/function.h"
 #include "src/tint/builtin/interpolation_sampling.h"
 #include "src/tint/builtin/interpolation_type.h"
 #include "src/tint/builtin/texel_format.h"
 #include "src/tint/diagnostic/diagnostic.h"
 #include "src/tint/symbol_table.h"
 #include "src/tint/utils/hashmap.h"

 namespace tint::resolver {

 /// UnresolvedIdentifier is the variant value used by ResolvedIdentifier
 struct UnresolvedIdentifier {
     /// Name of the unresolved identifier
     std::string name;
 };

 /// ResolvedIdentifier holds the resolution of an ast::Identifier.
 /// Can hold one of:
 /// - UnresolvedIdentifier
 /// - const ast::TypeDecl*  (as const ast::Node*)
 /// - const ast::Variable*  (as const ast::Node*)
 /// - const ast::Function*  (as const ast::Node*)
 /// - builtin::Function
 /// - builtin::Access
 /// - builtin::AddressSpace
 /// - builtin::Builtin
 /// - builtin::BuiltinValue
 /// - builtin::InterpolationSampling
 /// - builtin::InterpolationType
 /// - builtin::TexelFormat
 class ResolvedIdentifier {
   public:
     /// Constructor
     /// @param value the resolved identifier value
     template <typename T>
     ResolvedIdentifier(T value) : value_(value) {}  // NOLINT(runtime/explicit)

     /// @return the UnresolvedIdentifier if the identifier was not resolved
     const UnresolvedIdentifier* Unresolved() const {
         if (auto n = std::get_if<UnresolvedIdentifier>(&value_)) {
             return n;
         }
         return nullptr;
     }

     /// @return the node pointer if the ResolvedIdentifier holds an AST node, otherwise nullptr
     const ast::Node* Node() const {
         if (auto n = std::get_if<const ast::Node*>(&value_)) {
             return *n;
         }
         return nullptr;
     }

     /// @return the builtin function if the ResolvedIdentifier holds builtin::Function, otherwise
     /// builtin::Function::kNone
     builtin::Function BuiltinFunction() const {
         if (auto n = std::get_if<builtin::Function>(&value_)) {
             return *n;
         }
         return builtin::Function::kNone;
     }

     /// @return the access if the ResolvedIdentifier holds builtin::Access, otherwise
     /// builtin::Access::kUndefined
     builtin::Access Access() const {
         if (auto n = std::get_if<builtin::Access>(&value_)) {
             return *n;
         }
         return builtin::Access::kUndefined;
     }

     /// @return the address space if the ResolvedIdentifier holds builtin::AddressSpace, otherwise
     /// builtin::AddressSpace::kUndefined
     builtin::AddressSpace AddressSpace() const {
         if (auto n = std::get_if<builtin::AddressSpace>(&value_)) {
             return *n;
         }
         return builtin::AddressSpace::kUndefined;
     }

     /// @return the builtin type if the ResolvedIdentifier holds builtin::Builtin, otherwise
     /// builtin::Builtin::kUndefined
     builtin::Builtin BuiltinType() const {
         if (auto n = std::get_if<builtin::Builtin>(&value_)) {
             return *n;
         }
         return builtin::Builtin::kUndefined;
     }

     /// @return the builtin value if the ResolvedIdentifier holds builtin::BuiltinValue, otherwise
     /// builtin::BuiltinValue::kUndefined
     builtin::BuiltinValue BuiltinValue() const {
         if (auto n = std::get_if<builtin::BuiltinValue>(&value_)) {
             return *n;
         }
         return builtin::BuiltinValue::kUndefined;
     }

     /// @return the texel format if the ResolvedIdentifier holds type::InterpolationSampling,
     /// otherwise type::InterpolationSampling::kUndefined
     builtin::InterpolationSampling InterpolationSampling() const {
         if (auto n = std::get_if<builtin::InterpolationSampling>(&value_)) {
             return *n;
         }
         return builtin::InterpolationSampling::kUndefined;
     }

     /// @return the texel format if the ResolvedIdentifier holds type::InterpolationType,
     /// otherwise type::InterpolationType::kUndefined
     builtin::InterpolationType InterpolationType() const {
         if (auto n = std::get_if<builtin::InterpolationType>(&value_)) {
             return *n;
         }
         return builtin::InterpolationType::kUndefined;
     }

     /// @return the texel format if the ResolvedIdentifier holds type::TexelFormat, otherwise
     /// type::TexelFormat::kUndefined
     builtin::TexelFormat TexelFormat() const {
         if (auto n = std::get_if<builtin::TexelFormat>(&value_)) {
             return *n;
         }
         return builtin::TexelFormat::kUndefined;
     }

     /// @param value the value to compare the ResolvedIdentifier to
     /// @return true if the ResolvedIdentifier is equal to @p value
     template <typename T>
     bool operator==(const T& value) const {
         if (auto n = std::get_if<T>(&value_)) {
             return *n == value;
         }
         return false;
     }

     /// @param other the other value to compare to this
     /// @return true if this ResolvedIdentifier and @p other are not equal
     template <typename T>
     bool operator!=(const T& other) const {
         return !(*this == other);
     }

     /// @param symbols the program's symbol table
     /// @param diagnostics diagnostics used to report ICEs
     /// @return a description of the resolved symbol
     std::string String(const SymbolTable& symbols, diag::List& diagnostics) const;

   private:
     std::variant<UnresolvedIdentifier,
                  const ast::Node*,
                  builtin::Function,
                  builtin::Access,
                  builtin::AddressSpace,
                  builtin::Builtin,
                  builtin::BuiltinValue,
                  builtin::InterpolationSampling,
                  builtin::InterpolationType,
                  builtin::TexelFormat>
         value_;
 };

 /// DependencyGraph holds information about module-scope declaration dependency
 /// analysis and symbol resolutions.
 struct DependencyGraph {
     /// Constructor
     DependencyGraph();
     /// Move-constructor
     DependencyGraph(DependencyGraph&&);
     /// Destructor
     ~DependencyGraph();

     /// Build() performs symbol resolution and dependency analysis on `module`,
     /// populating `output` with the resulting dependency graph.
     /// @param module the AST module to analyse
     /// @param symbols the symbol table
     /// @param diagnostics the diagnostic list to populate with errors / warnings
     /// @param output the resulting DependencyGraph
     /// @returns true on success, false on error
     static bool Build(const ast::Module& module,
                       const SymbolTable& symbols,
                       diag::List& diagnostics,
                       DependencyGraph& output);

     /// All globals in dependency-sorted order.
     utils::Vector<const ast::Node*, 32> ordered_globals;

     /// Map of ast::Identifier to a ResolvedIdentifier
     utils::Hashmap<const ast::Identifier*, ResolvedIdentifier, 64> resolved_identifiers;

     /// Map of ast::Variable to a type, function, or variable that is shadowed by
     /// the variable key. A declaration (X) shadows another (Y) if X and Y use
     /// the same symbol, and X is declared in a sub-scope of the scope that
     /// declares Y.
     utils::Hashmap<const ast::Variable*, const ast::Node*, 16> shadows;
 };

 }  // namespace tint::resolver

 #endif  // SRC_TINT_RESOLVER_DEPENDENCY_GRAPH_H_
	// Copyright 2021 The Tint Authors.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#ifndef SRC_TINT_RESOLVER_DEPENDENCY_GRAPH_H_
	#define SRC_TINT_RESOLVER_DEPENDENCY_GRAPH_H_

	#include <string>
	#include <vector>

	#include "src/tint/ast/module.h"
	#include "src/tint/builtin/access.h"
	#include "src/tint/builtin/builtin.h"
	#include "src/tint/builtin/builtin_value.h"
	#include "src/tint/builtin/function.h"
	#include "src/tint/builtin/interpolation_sampling.h"
	#include "src/tint/builtin/interpolation_type.h"
	#include "src/tint/builtin/texel_format.h"
	#include "src/tint/diagnostic/diagnostic.h"
	#include "src/tint/symbol_table.h"
	#include "src/tint/utils/hashmap.h"

	namespace tint::resolver {

	/// UnresolvedIdentifier is the variant value used by ResolvedIdentifier
	struct UnresolvedIdentifier {
	/// Name of the unresolved identifier
	std::string name;
	};

	/// ResolvedIdentifier holds the resolution of an ast::Identifier.
	/// Can hold one of:
	/// - UnresolvedIdentifier
	/// - const ast::TypeDecl* (as const ast::Node*)
	/// - const ast::Variable* (as const ast::Node*)
	/// - const ast::Function* (as const ast::Node*)
	/// - builtin::Function
	/// - builtin::Access
	/// - builtin::AddressSpace
	/// - builtin::Builtin
	/// - builtin::BuiltinValue
	/// - builtin::InterpolationSampling
	/// - builtin::InterpolationType
	/// - builtin::TexelFormat
	class ResolvedIdentifier {
	public:
	/// Constructor
	/// @param value the resolved identifier value
	template <typename T>
	ResolvedIdentifier(T value) : value_(value) {} // NOLINT(runtime/explicit)

	/// @return the UnresolvedIdentifier if the identifier was not resolved
	const UnresolvedIdentifier* Unresolved() const {
	if (auto n = std::get_if<UnresolvedIdentifier>(&value_)) {
	return n;
	}
	return nullptr;
	}

	/// @return the node pointer if the ResolvedIdentifier holds an AST node, otherwise nullptr
	const ast::Node* Node() const {
	if (auto n = std::get_if<const ast::Node*>(&value_)) {
	return *n;
	}
	return nullptr;
	}

	/// @return the builtin function if the ResolvedIdentifier holds builtin::Function, otherwise
	/// builtin::Function::kNone
	builtin::Function BuiltinFunction() const {
	if (auto n = std::get_if<builtin::Function>(&value_)) {
	return *n;
	}
	return builtin::Function::kNone;
	}

	/// @return the access if the ResolvedIdentifier holds builtin::Access, otherwise
	/// builtin::Access::kUndefined
	builtin::Access Access() const {
	if (auto n = std::get_if<builtin::Access>(&value_)) {
	return *n;
	}
	return builtin::Access::kUndefined;
	}

	/// @return the address space if the ResolvedIdentifier holds builtin::AddressSpace, otherwise
	/// builtin::AddressSpace::kUndefined
	builtin::AddressSpace AddressSpace() const {
	if (auto n = std::get_if<builtin::AddressSpace>(&value_)) {
	return *n;
	}
	return builtin::AddressSpace::kUndefined;
	}

	/// @return the builtin type if the ResolvedIdentifier holds builtin::Builtin, otherwise
	/// builtin::Builtin::kUndefined
	builtin::Builtin BuiltinType() const {
	if (auto n = std::get_if<builtin::Builtin>(&value_)) {
	return *n;
	}
	return builtin::Builtin::kUndefined;
	}

	/// @return the builtin value if the ResolvedIdentifier holds builtin::BuiltinValue, otherwise
	/// builtin::BuiltinValue::kUndefined
	builtin::BuiltinValue BuiltinValue() const {
	if (auto n = std::get_if<builtin::BuiltinValue>(&value_)) {
	return *n;
	}
	return builtin::BuiltinValue::kUndefined;
	}

	/// @return the texel format if the ResolvedIdentifier holds type::InterpolationSampling,
	/// otherwise type::InterpolationSampling::kUndefined
	builtin::InterpolationSampling InterpolationSampling() const {
	if (auto n = std::get_if<builtin::InterpolationSampling>(&value_)) {
	return *n;
	}
	return builtin::InterpolationSampling::kUndefined;
	}

	/// @return the texel format if the ResolvedIdentifier holds type::InterpolationType,
	/// otherwise type::InterpolationType::kUndefined
	builtin::InterpolationType InterpolationType() const {
	if (auto n = std::get_if<builtin::InterpolationType>(&value_)) {
	return *n;
	}
	return builtin::InterpolationType::kUndefined;
	}

	/// @return the texel format if the ResolvedIdentifier holds type::TexelFormat, otherwise
	/// type::TexelFormat::kUndefined
	builtin::TexelFormat TexelFormat() const {
	if (auto n = std::get_if<builtin::TexelFormat>(&value_)) {
	return *n;
	}
	return builtin::TexelFormat::kUndefined;
	}

	/// @param value the value to compare the ResolvedIdentifier to
	/// @return true if the ResolvedIdentifier is equal to @p value
	template <typename T>
	bool operator==(const T& value) const {
	if (auto n = std::get_if<T>(&value_)) {
	return *n == value;
	}
	return false;
	}

	/// @param other the other value to compare to this
	/// @return true if this ResolvedIdentifier and @p other are not equal
	template <typename T>
	bool operator!=(const T& other) const {
	return !(*this == other);
	}

	/// @param symbols the program's symbol table
	/// @param diagnostics diagnostics used to report ICEs
	/// @return a description of the resolved symbol
	std::string String(const SymbolTable& symbols, diag::List& diagnostics) const;

	private:
	std::variant<UnresolvedIdentifier,
	const ast::Node*,
	builtin::Function,
	builtin::Access,
	builtin::AddressSpace,
	builtin::Builtin,
	builtin::BuiltinValue,
	builtin::InterpolationSampling,
	builtin::InterpolationType,
	builtin::TexelFormat>
	value_;
	};

	/// DependencyGraph holds information about module-scope declaration dependency
	/// analysis and symbol resolutions.
	struct DependencyGraph {
	/// Constructor
	DependencyGraph();
	/// Move-constructor
	DependencyGraph(DependencyGraph&&);
	/// Destructor
	~DependencyGraph();

	/// Build() performs symbol resolution and dependency analysis on `module`,
	/// populating `output` with the resulting dependency graph.
	/// @param module the AST module to analyse
	/// @param symbols the symbol table
	/// @param diagnostics the diagnostic list to populate with errors / warnings
	/// @param output the resulting DependencyGraph
	/// @returns true on success, false on error
	static bool Build(const ast::Module& module,
	const SymbolTable& symbols,
	diag::List& diagnostics,
	DependencyGraph& output);

	/// All globals in dependency-sorted order.
	utils::Vector<const ast::Node*, 32> ordered_globals;

	/// Map of ast::Identifier to a ResolvedIdentifier
	utils::Hashmap<const ast::Identifier*, ResolvedIdentifier, 64> resolved_identifiers;

	/// Map of ast::Variable to a type, function, or variable that is shadowed by
	/// the variable key. A declaration (X) shadows another (Y) if X and Y use
	/// the same symbol, and X is declared in a sub-scope of the scope that
	/// declares Y.
	utils::Hashmap<const ast::Variable, const ast::Node, 16> shadows;
	};

	} // namespace tint::resolver

	#endif // SRC_TINT_RESOLVER_DEPENDENCY_GRAPH_H_