source: src/Validate/ForallPointerDecay.cpp

//
// Cforall Version 1.0.0 Copyright (C) 2018 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// ForallPointerDecay.cpp --
//
// Author           : Andrew Beach
// Created On       : Tue Dec  7 16:15:00 2021
// Last Modified By : Peter A. Buhr
// Last Modified On : Sun Nov 26 18:49:57 2023
// Update Count     : 2
//

#include "ForallPointerDecay.hpp"

#include "AST/Copy.hpp"
#include "AST/Decl.hpp"
#include "AST/DeclReplacer.hpp"
#include "AST/Pass.hpp"
#include "CodeGen/OperatorTable.h"
#include "Common/CodeLocation.h"
#include "Common/ToString.hpp"
#include "Common/utility.h"
#include "SymTab/FixFunction.h"

namespace Validate {

namespace {

// Create a function type only using information on the FunctionDecl.
ast::FunctionType * makeFuncType( const ast::FunctionDecl * decl ) {
        auto type = new ast::FunctionType( decl->type->isVarArgs );
        for ( auto & param : decl->params ) {
                type->params.emplace_back( param->get_type() );
        }
        for ( auto & ret : decl->returns ) {
                type->returns.emplace_back( ret->get_type() );
        }
        for ( auto & type_param : decl->type_params ) {
                type->forall.emplace_back(
                        new ast::TypeInstType( type_param ) );
        }
        for ( auto & assertion : decl->assertions ) {
                type->assertions.emplace_back( new ast::VariableExpr(
                        assertion->location, assertion ) );
        }
        return type;
}

ast::FunctionDecl * updateAssertions( ast::FunctionDecl * decl ) {
        auto type = ast::mutate( decl->type.get() );
        type->assertions.clear();
        type->assertions.reserve( decl->assertions.size() );
        for ( auto & assertion : decl->assertions ) {
                type->assertions.emplace_back(
                        new ast::VariableExpr( decl->location, assertion ) );
        }
        decl->type = type;
        return decl;
}

// Component Passes:
/// Expand assertions from a trait instance,
/// performing appropriate type variable substitutions.
struct TraitExpander final {
        using AssertionList = std::vector<ast::ptr<ast::DeclWithType>>;

        static AssertionList expandTrait( const ast::TraitInstType * inst ) {
                assertf( inst->base, "Trait instance not linked to base trait: %s",
                        toCString( inst ) );
                AssertionList assertions;
                // Substitute trait decl parameters for instance parameters.
                ast::TypeSubstitution sub( inst->base->params, inst->params );
                for ( const ast::ptr<ast::Decl> & decl : inst->base->members ) {
                        ast::ptr<ast::DeclWithType> copy =
                                ast::deepCopy( decl.strict_as<ast::DeclWithType>() );

                        int count = sub.apply( copy );
                        (void)count;

                        // Update the type (type substution does not seem to cover it).
                        if ( auto func = copy.as<ast::FunctionDecl>() ) {
                                auto mut = ast::mutate( func );
                                mut->type = makeFuncType( func );
                                copy = mut;
                        }
                        assertions.push_back( copy );
                }
                return assertions;
        }

        static AssertionList expandAssertions( const AssertionList & old ) {
                AssertionList assertions;
                for ( const ast::ptr<ast::DeclWithType> & decl : old ) {
                        if ( auto traitInst = dynamic_cast<const ast::TraitInstType *>(
                                        decl->get_type() ) ) {
                                auto moreAsserts = expandTrait( traitInst );
                                splice( assertions, moreAsserts );
                        } else {
                                assertions.push_back( decl );
                        }
                }
                return assertions;
        }

        using TypeDeclVec = std::vector<ast::ptr<ast::TypeDecl>>;

        static TypeDeclVec expandTypeDecls( const TypeDeclVec & old ) {
                TypeDeclVec typeDecls;
                typeDecls.reserve( old.size() );
                for ( const ast::TypeDecl * typeDecl : old ) {
                        typeDecls.push_back( ast::mutate_field( typeDecl,
                                &ast::TypeDecl::assertions,
                                expandAssertions( typeDecl->assertions ) ) );
                }
                return typeDecls;
        }

        const ast::FunctionDecl * postvisit( const ast::FunctionDecl * decl ) {
                if ( decl->assertions.empty() ) {
                        return decl;
                }
                auto mut = ast::mutate( decl );
                mut->assertions = expandAssertions( decl->assertions );
                // Update the assertion list on the type as well.
                return updateAssertions( mut );
        }

        const ast::StructDecl * previsit( const ast::StructDecl * decl ) {
                if ( decl->params.empty() ) {
                        return decl;
                }
                return ast::mutate_field( decl, &ast::StructDecl::params,
                        expandTypeDecls( decl->params ) );
        }

        const ast::UnionDecl * previsit( const ast::UnionDecl * decl ) {
                if ( decl->params.empty() ) {
                        return decl;
                }
                return ast::mutate_field( decl, &ast::UnionDecl::params,
                        expandTypeDecls( decl->params ) );
        }
};

std::vector<ast::ptr<ast::DeclWithType>> fixAssertionList(
                const ast::ParseNode * node,
                const std::vector<ast::ptr<ast::DeclWithType>> & assertions ) {
        std::vector<ast::ptr<ast::DeclWithType>> ret;
        ret.reserve( assertions.size() );
        for ( const auto & assn : assertions ) {
                bool isVoid = false;
                ret.push_back( SymTab::fixFunction( assn, isVoid ) );
                if ( isVoid ) {
                        SemanticError( node->location, node,
                                "invalid type void in assertion of function " );
                }
        }
        return ret;
}

std::vector<ast::ptr<ast::TypeDecl>> fixTypeDeclList(
                const ast::ParseNode * node,
                const std::vector<ast::ptr<ast::TypeDecl>> & type_params ) {
        std::vector<ast::ptr<ast::TypeDecl>> ret;
        ret.reserve( type_params.size() );
        for ( const ast::TypeDecl * type_param : type_params ) {
                auto mutParam = ast::mutate( type_param );
                mutParam->assertions = fixAssertionList( node, mutParam->assertions );
                ret.push_back( mutParam );
        }
        return ret;
}

struct AssertionFunctionFixer final {
        const ast::FunctionDecl * previsit( const ast::FunctionDecl * decl ) {
                if ( decl->assertions.empty() ) {
                        return decl;
                }
                return ast::mutate_field( decl, &ast::FunctionDecl::assertions,
                        fixAssertionList( decl, decl->assertions ) );
        }

        const ast::FunctionDecl * postvisit( const ast::FunctionDecl * decl ) {
                if ( decl->assertions.empty() ) {
                        return decl;
                }
                return updateAssertions( mutate( decl ) );
        }

        const ast::StructDecl * previsit( const ast::StructDecl * decl ) {
                if ( decl->params.empty() ) {
                        return decl;
                }
                return ast::mutate_field( decl, &ast::StructDecl::params,
                        fixTypeDeclList( decl, decl->params ) );
        }

        const ast::UnionDecl * previsit( const ast::UnionDecl * decl ) {
                if ( decl->params.empty() ) {
                        return decl;
                }
                return ast::mutate_field( decl, &ast::UnionDecl::params,
                        fixTypeDeclList( decl, decl->params ) );
        }
};

struct OperatorChecker final {
        void previsit( const ast::ObjectDecl * obj ) {
                if ( !CodeGen::isOperator( obj->name ) ) return;
                auto type = obj->type->stripDeclarator();
                if ( dynamic_cast< const ast::FunctionType * >( type ) ) return;
                SemanticError( obj->location, "operator %s is not a function or function pointer.", obj->name.c_str() );
        }
};

struct UniqueFixCore final {
        const ast::DeclWithType * postvisit( const ast::DeclWithType * decl ) {
                if ( decl->uniqueId ) {
                        return decl;
                } else {
                        auto mut = ast::mutate( decl );
                        mut->fixUniqueId();
                        return mut;
                }
        }
};

} // namespace

void decayForallPointers( ast::TranslationUnit & transUnit ) {
        ast::Pass<TraitExpander>::run( transUnit );
        ast::Pass<AssertionFunctionFixer>::run( transUnit );
        ast::Pass<OperatorChecker>::run( transUnit );
}

void fixUniqueIds( ast::TranslationUnit & transUnit ) {
        ast::Pass<UniqueFixCore>::run( transUnit );
}

std::vector<ast::ptr<ast::DeclWithType>> expandAssertions(
                std::vector<ast::ptr<ast::DeclWithType>> const & old ) {
        return TraitExpander::expandAssertions( old );
}

} // namespace Validate

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //