//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// MutexFuncHash.hpp -- Hash utility for mutex function identity.
//
// Author           : Matthew Au-Yeung
// Created On       : Tue Jan 28 2026
//

#pragma once

#include <cstdint>
#include <string>

#include "AST/Decl.hpp"
#include "AST/Expr.hpp"
#include "SymTab/Mangler.hpp"

namespace Concurrency {

// FNV-1a hash of a function declaration's mangled name.
// Used to identify mutex functions across translation units,
// since function pointers may differ for static inline functions.
static inline uint64_t hashMangle( const ast::DeclWithType * decl ) {
	std::string name = Mangle::mangleType( decl );
	uint64_t hash = 14695981039346656037ULL; // FNV offset basis
	for ( char c : name ) {
		hash ^= static_cast<uint64_t>( c );
		hash *= 1099511628211ULL; // FNV prime
	}
	return hash;
}

// Create a ConstantExpr with the hash of the mangled name.
static inline ast::ConstantExpr * hashMangleExpr( 
	const CodeLocation & location, const ast::DeclWithType * decl ) {
	return ast::ConstantExpr::from_ulonglong( location, hashMangle( decl ) );
}

} // namespace Concurrency