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// Copyright 2020 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_RESOLVER_H_
#define SRC_TINT_RESOLVER_RESOLVER_H_
#include <memory>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include "src/tint/program_builder.h"
#include "src/tint/resolver/const_eval.h"
#include "src/tint/resolver/dependency_graph.h"
#include "src/tint/resolver/intrinsic_table.h"
#include "src/tint/resolver/sem_helper.h"
#include "src/tint/resolver/validator.h"
#include "src/tint/scope_stack.h"
#include "src/tint/sem/binding_point.h"
#include "src/tint/sem/block_statement.h"
#include "src/tint/sem/constant.h"
#include "src/tint/sem/function.h"
#include "src/tint/sem/struct.h"
#include "src/tint/utils/bitset.h"
#include "src/tint/utils/unique_vector.h"
// Forward declarations
namespace tint::ast {
class IndexAccessorExpression;
class BinaryExpression;
class BitcastExpression;
class CallExpression;
class CallStatement;
class CaseStatement;
class ForLoopStatement;
class Function;
class IdentifierExpression;
class LoopStatement;
class MemberAccessorExpression;
class ReturnStatement;
class SwitchStatement;
class UnaryOpExpression;
class Variable;
class WhileStatement;
} // namespace tint::ast
namespace tint::sem {
class Array;
class BlockStatement;
class Builtin;
class CaseStatement;
class ForLoopStatement;
class IfStatement;
class LoopStatement;
class Statement;
class StructMember;
class SwitchStatement;
class TypeInitializer;
class WhileStatement;
} // namespace tint::sem
namespace tint::type {
class Atomic;
} // namespace tint::type
namespace tint::resolver {
/// Resolves types for all items in the given tint program
class Resolver {
public:
/// Constructor
/// @param builder the program builder
explicit Resolver(ProgramBuilder* builder);
/// Destructor
~Resolver();
/// @returns error messages from the resolver
std::string error() const { return diagnostics_.str(); }
/// @returns true if the resolver was successful
bool Resolve();
/// @param type the given type
/// @returns true if the given type is a plain type
bool IsPlain(const type::Type* type) const { return validator_.IsPlain(type); }
/// @param type the given type
/// @returns true if the given type is a fixed-footprint type
bool IsFixedFootprint(const type::Type* type) const {
return validator_.IsFixedFootprint(type);
}
/// @param type the given type
/// @returns true if the given type is storable
bool IsStorable(const type::Type* type) const { return validator_.IsStorable(type); }
/// @param type the given type
/// @returns true if the given type is host-shareable
bool IsHostShareable(const type::Type* type) const { return validator_.IsHostShareable(type); }
/// @returns the validator for testing
const Validator* GetValidatorForTesting() const { return &validator_; }
private:
/// Resolves the program, without creating final the semantic nodes.
/// @returns true on success, false on error
bool ResolveInternal();
/// Creates the nodes and adds them to the sem::Info mappings of the
/// ProgramBuilder.
void CreateSemanticNodes() const;
/// Expression traverses the graph of expressions starting at `expr`, building a postordered
/// list (leaf-first) of all the expression nodes. Each of the expressions are then resolved by
/// dispatching to the appropriate expression handlers below.
/// @returns the resolved semantic node for the expression `expr`, or nullptr on failure.
sem::Expression* Expression(const ast::Expression* expr);
////////////////////////////////////////////////////////////////////////////////////////////////
// Expression resolving methods
//
// Returns the semantic node pointer on success, nullptr on failure.
//
// These methods are invoked by Expression(), in postorder (child-first). These methods should
// not attempt to resolve their children. This design avoids recursion, which is a common cause
// of stack-overflows.
////////////////////////////////////////////////////////////////////////////////////////////////
sem::Expression* IndexAccessor(const ast::IndexAccessorExpression*);
sem::Expression* Binary(const ast::BinaryExpression*);
sem::Expression* Bitcast(const ast::BitcastExpression*);
sem::Call* Call(const ast::CallExpression*);
sem::Function* Function(const ast::Function*);
template <size_t N>
sem::Call* FunctionCall(const ast::CallExpression*,
sem::Function* target,
utils::Vector<const sem::Expression*, N>& args,
sem::Behaviors arg_behaviors);
sem::Expression* Identifier(const ast::IdentifierExpression*);
template <size_t N>
sem::Call* BuiltinCall(const ast::CallExpression*,
sem::BuiltinType,
utils::Vector<const sem::Expression*, N>& args);
sem::Expression* Literal(const ast::LiteralExpression*);
sem::Expression* MemberAccessor(const ast::MemberAccessorExpression*);
sem::Expression* UnaryOp(const ast::UnaryOpExpression*);
/// Register a memory load from an expression, to track accesses to root identifiers in order to
/// perform alias analysis.
void RegisterLoadIfNeeded(const sem::Expression* expr);
/// Register a memory store to an expression, to track accesses to root identifiers in order to
/// perform alias analysis.
void RegisterStore(const sem::Expression* expr);
/// Perform pointer alias analysis for `call`.
/// @returns true is the call arguments are free from aliasing issues, false otherwise.
bool AliasAnalysis(const sem::Call* call);
/// If `expr` is not of an abstract-numeric type, then Materialize() will just return `expr`.
/// If `expr` is of an abstract-numeric type:
/// * Materialize will create and return a sem::Materialize node wrapping `expr`.
/// * The AST -> Sem binding will be updated to point to the new sem::Materialize node.
/// * The sem::Materialize node will have a new concrete type, which will be `target_type` if
/// not nullptr, otherwise:
/// * a type with the element type of `i32` (e.g. `i32`, `vec2<i32>`) if `expr` has a
/// element type of abstract-integer...
/// * ... or a type with the element type of `f32` (e.g. `f32`, vec3<f32>`, `mat2x3<f32>`)
/// if `expr` has a element type of abstract-float.
/// * The sem::Materialize constant value will be the value of `expr` value-converted to the
/// materialized type.
/// If `expr` is nullptr, then Materialize() will also return nullptr.
const sem::Expression* Materialize(const sem::Expression* expr,
const type::Type* target_type = nullptr);
/// Materializes all the arguments in `args` to the parameter types of `target`.
/// @returns true on success, false on failure.
template <size_t N>
bool MaybeMaterializeArguments(utils::Vector<const sem::Expression*, N>& args,
const sem::CallTarget* target);
/// @returns true if an argument of an abstract numeric type, passed to a parameter of type
/// `parameter_ty` should be materialized.
bool ShouldMaterializeArgument(const type::Type* parameter_ty) const;
/// Converts `c` to `target_ty`
/// @returns true on success, false on failure.
bool Convert(const sem::Constant*& c, const type::Type* target_ty, const Source& source);
/// Transforms `args` to a vector of constants, and converts each constant to the call target's
/// parameter type.
/// @returns the vector of constants, `utils::Failure` on failure.
template <size_t N>
utils::Result<utils::Vector<const sem::Constant*, N>> ConvertArguments(
const utils::Vector<const sem::Expression*, N>& args,
const sem::CallTarget* target);
/// @param ty the type that may hold abstract numeric types
/// @param target_ty the target type for the expression (variable type, parameter type, etc).
/// May be nullptr.
/// @param source the source of the expression requiring materialization
/// @returns the concrete (materialized) type for the given type, or nullptr if the type is
/// already concrete.
const type::Type* ConcreteType(const type::Type* ty,
const type::Type* target_ty,
const Source& source);
// Statement resolving methods
// Each return true on success, false on failure.
sem::Statement* AssignmentStatement(const ast::AssignmentStatement*);
sem::BlockStatement* BlockStatement(const ast::BlockStatement*);
sem::Statement* BreakStatement(const ast::BreakStatement*);
sem::Statement* BreakIfStatement(const ast::BreakIfStatement*);
sem::Statement* CallStatement(const ast::CallStatement*);
sem::CaseStatement* CaseStatement(const ast::CaseStatement*, const type::Type*);
sem::Statement* CompoundAssignmentStatement(const ast::CompoundAssignmentStatement*);
sem::Statement* ContinueStatement(const ast::ContinueStatement*);
sem::Statement* DiscardStatement(const ast::DiscardStatement*);
sem::ForLoopStatement* ForLoopStatement(const ast::ForLoopStatement*);
sem::WhileStatement* WhileStatement(const ast::WhileStatement*);
sem::GlobalVariable* GlobalVariable(const ast::Variable*);
sem::Statement* Parameter(const ast::Variable*);
sem::IfStatement* IfStatement(const ast::IfStatement*);
sem::Statement* IncrementDecrementStatement(const ast::IncrementDecrementStatement*);
sem::LoopStatement* LoopStatement(const ast::LoopStatement*);
sem::Statement* ReturnStatement(const ast::ReturnStatement*);
sem::Statement* Statement(const ast::Statement*);
sem::Statement* StaticAssert(const ast::StaticAssert*);
sem::SwitchStatement* SwitchStatement(const ast::SwitchStatement* s);
sem::Statement* VariableDeclStatement(const ast::VariableDeclStatement*);
bool Statements(utils::VectorRef<const ast::Statement*>);
// CollectTextureSamplerPairs() collects all the texture/sampler pairs from the target function
// / builtin, and records these on the current function by calling AddTextureSamplerPair().
void CollectTextureSamplerPairs(sem::Function* func,
utils::VectorRef<const sem::Expression*> args) const;
void CollectTextureSamplerPairs(const sem::Builtin* builtin,
utils::VectorRef<const sem::Expression*> args) const;
/// Resolves the WorkgroupSize for the given function, assigning it to
/// current_function_
bool WorkgroupSize(const ast::Function*);
/// @returns the type::Type for the ast::Type `ty`, building it if it
/// hasn't been constructed already. If an error is raised, nullptr is
/// returned.
/// @param ty the ast::Type
type::Type* Type(const ast::Type* ty);
/// @param enable the enable declaration
/// @returns the resolved extension
bool Enable(const ast::Enable* enable);
/// @param named_type the named type to resolve
/// @returns the resolved semantic type
type::Type* TypeDecl(const ast::TypeDecl* named_type);
/// Builds and returns the semantic information for the AST array `arr`.
/// This method does not mark the ast::Array node, nor attach the generated semantic information
/// to the AST node.
/// @returns the semantic Array information, or nullptr if an error is raised.
/// @param arr the Array to get semantic information for
type::Array* Array(const ast::Array* arr);
/// Resolves and validates the expression used as the count parameter of an array.
/// @param count_expr the expression used as the second template parameter to an array<>.
/// @returns the number of elements in the array.
const type::ArrayCount* ArrayCount(const ast::Expression* count_expr);
/// Resolves and validates the attributes on an array.
/// @param attributes the attributes on the array type.
/// @param el_ty the element type of the array.
/// @param explicit_stride assigned the specified stride of the array in bytes.
/// @returns true on success, false on failure
bool ArrayAttributes(utils::VectorRef<const ast::Attribute*> attributes,
const type::Type* el_ty,
uint32_t& explicit_stride);
/// Builds and returns the semantic information for an array.
/// @returns the semantic Array information, or nullptr if an error is raised.
/// @param el_source the source of the array element, or the array if the array does not have a
/// locally-declared element AST node.
/// @param count_source the source of the array count, or the array if the array does not have a
/// locally-declared element AST node.
/// @param el_ty the Array element type
/// @param el_count the number of elements in the array.
/// @param explicit_stride the explicit byte stride of the array. Zero means implicit stride.
type::Array* Array(const Source& el_source,
const Source& count_source,
const type::Type* el_ty,
const type::ArrayCount* el_count,
uint32_t explicit_stride);
/// Builds and returns the semantic information for the alias `alias`.
/// This method does not mark the ast::Alias node, nor attach the generated
/// semantic information to the AST node.
/// @returns the aliased type, or nullptr if an error is raised.
type::Type* Alias(const ast::Alias* alias);
/// Builds and returns the semantic information for the structure `str`.
/// This method does not mark the ast::Struct node, nor attach the generated
/// semantic information to the AST node.
/// @returns the semantic Struct information, or nullptr if an error is
/// raised.
sem::Struct* Structure(const ast::Struct* str);
/// @returns the semantic info for the variable `v`. If an error is raised, nullptr is
/// returned.
/// @note this method does not resolve the attributes as these are context-dependent (global,
/// local)
/// @param var the variable
/// @param is_global true if this is module scope, otherwise function scope
sem::Variable* Variable(const ast::Variable* var, bool is_global);
/// @returns the semantic info for the `ast::Let` `v`. If an error is raised, nullptr is
/// returned.
/// @note this method does not resolve the attributes as these are context-dependent (global,
/// local)
/// @param var the variable
/// @param is_global true if this is module scope, otherwise function scope
sem::Variable* Let(const ast::Let* var, bool is_global);
/// @returns the semantic info for the module-scope `ast::Override` `v`. If an error is raised,
/// nullptr is returned.
/// @note this method does not resolve the attributes as these are context-dependent (global,
/// local)
/// @param override the variable
sem::Variable* Override(const ast::Override* override);
/// @returns the semantic info for an `ast::Const` `v`. If an error is raised, nullptr is
/// returned.
/// @note this method does not resolve the attributes as these are context-dependent (global,
/// local)
/// @param const_ the variable
/// @param is_global true if this is module scope, otherwise function scope
sem::Variable* Const(const ast::Const* const_, bool is_global);
/// @returns the semantic info for the `ast::Var` `var`. If an error is raised, nullptr is
/// returned.
/// @note this method does not resolve the attributes as these are context-dependent (global,
/// local)
/// @param var the variable
/// @param is_global true if this is module scope, otherwise function scope
sem::Variable* Var(const ast::Var* var, bool is_global);
/// @returns the semantic info for the function parameter `param`. If an error is raised,
/// nullptr is returned.
/// @note the caller is expected to validate the parameter
/// @param param the AST parameter
/// @param index the index of the parameter
sem::Parameter* Parameter(const ast::Parameter* param, uint32_t index);
/// @returns the location value for a `@location` attribute, validating the value's range and
/// type.
utils::Result<uint32_t> LocationAttribute(const ast::LocationAttribute* attr);
/// Records the address space usage for the given type, and any transient
/// dependencies of the type. Validates that the type can be used for the
/// given address space, erroring if it cannot.
/// @param sc the address space to apply to the type and transitent types
/// @param ty the type to apply the address space on
/// @param usage the Source of the root variable declaration that uses the
/// given type and address space. Used for generating sensible error
/// messages.
/// @returns true on success, false on error
bool ApplyAddressSpaceUsageToType(ast::AddressSpace sc, type::Type* ty, const Source& usage);
/// @param address_space the address space
/// @returns the default access control for the given address space
ast::Access DefaultAccessForAddressSpace(ast::AddressSpace address_space);
/// Allocate constant IDs for pipeline-overridable constants.
/// @returns true on success, false on error
bool AllocateOverridableConstantIds();
/// Set the shadowing information on variable declarations.
/// @note this method must only be called after all semantic nodes are built.
void SetShadows();
/// StatementScope() does the following:
/// * Creates the AST -> SEM mapping.
/// * Assigns `sem` to #current_statement_
/// * Assigns `sem` to #current_compound_statement_ if `sem` derives from
/// sem::CompoundStatement.
/// * Then calls `callback`.
/// * Before returning #current_statement_ and #current_compound_statement_ are restored to
/// their original values.
/// @returns `sem` if `callback` returns true, otherwise `nullptr`.
template <typename SEM, typename F>
SEM* StatementScope(const ast::Statement* ast, SEM* sem, F&& callback);
/// Mark records that the given AST node has been visited, and asserts that
/// the given node has not already been seen. Diamonds in the AST are
/// illegal.
/// @param node the AST node.
/// @returns true on success, false on error
bool Mark(const ast::Node* node);
/// Adds the given error message to the diagnostics
void AddError(const std::string& msg, const Source& source) const;
/// Adds the given warning message to the diagnostics
void AddWarning(const std::string& msg, const Source& source) const;
/// Adds the given note message to the diagnostics
void AddNote(const std::string& msg, const Source& source) const;
/// @returns true if the symbol is the name of a builtin function.
bool IsBuiltin(Symbol) const;
/// @returns the builtin type alias for the given symbol
type::Type* BuiltinTypeAlias(Symbol) const;
// ArrayInitializerSig represents a unique array initializer signature.
// It is a tuple of the array type, number of arguments provided and earliest evaluation stage.
using ArrayInitializerSig =
utils::UnorderedKeyWrapper<std::tuple<const type::Array*, size_t, sem::EvaluationStage>>;
// StructInitializerSig represents a unique structure initializer signature.
// It is a tuple of the structure type, number of arguments provided and earliest evaluation
// stage.
using StructInitializerSig =
utils::UnorderedKeyWrapper<std::tuple<const sem::Struct*, size_t, sem::EvaluationStage>>;
/// ExprEvalStageConstraint describes a constraint on when expressions can be evaluated.
struct ExprEvalStageConstraint {
/// The latest stage that the expression can be evaluated
sem::EvaluationStage stage = sem::EvaluationStage::kRuntime;
/// The 'thing' that is imposing the contraint. e.g. "var declaration"
/// If nullptr, then there is no constraint
const char* constraint = nullptr;
};
/// AliasAnalysisInfo captures the memory accesses performed by a given function for the purpose
/// of determining if any two arguments alias at any callsite.
struct AliasAnalysisInfo {
/// The set of module-scope variables that are written to, and where that write occurs.
std::unordered_map<const sem::Variable*, const sem::Expression*> module_scope_writes;
/// The set of module-scope variables that are read from, and where that read occurs.
std::unordered_map<const sem::Variable*, const sem::Expression*> module_scope_reads;
/// The set of function parameters that are written to.
std::unordered_set<const sem::Variable*> parameter_writes;
/// The set of function parameters that are read from.
std::unordered_set<const sem::Variable*> parameter_reads;
};
ProgramBuilder* const builder_;
diag::List& diagnostics_;
ConstEval const_eval_;
std::unique_ptr<IntrinsicTable> const intrinsic_table_;
DependencyGraph dependencies_;
SemHelper sem_;
Validator validator_;
ast::Extensions enabled_extensions_;
utils::Vector<sem::Function*, 8> entry_points_;
utils::Hashmap<const type::Type*, const Source*, 8> atomic_composite_info_;
utils::Bitset<0> marked_;
ExprEvalStageConstraint expr_eval_stage_constraint_;
std::unordered_map<const sem::Function*, AliasAnalysisInfo> alias_analysis_infos_;
utils::Hashmap<OverrideId, const sem::Variable*, 8> override_ids_;
utils::Hashmap<ArrayInitializerSig, sem::CallTarget*, 8> array_inits_;
utils::Hashmap<StructInitializerSig, sem::CallTarget*, 8> struct_inits_;
sem::Function* current_function_ = nullptr;
sem::Statement* current_statement_ = nullptr;
sem::CompoundStatement* current_compound_statement_ = nullptr;
uint32_t current_scoping_depth_ = 0;
utils::UniqueVector<const sem::GlobalVariable*, 4>* resolved_overrides_ = nullptr;
utils::Hashset<TypeAndAddressSpace, 8> valid_type_storage_layouts_;
utils::Hashmap<const ast::Expression*, const ast::BinaryExpression*, 8>
logical_binary_lhs_to_parent_;
utils::Hashset<const ast::Expression*, 8> skip_const_eval_;
};
} // namespace tint::resolver
#endif // SRC_TINT_RESOLVER_RESOLVER_H_