CSE 3302 Exam 3 Chapter 7 Slides

Syntax

What the language constructs look like

Semantics

What the language constructs actually do; expected behavior

Language Reference Manual

Common way to specify semantics using natural language, often imprecise

Translator Definition

Specifies semantics by implementing a compiler or interpreter

Formal Definition

Uses mathematical methods to precisely define semantics

Denotational Semantics

Formal method describing program behavior using functions

Name (Identifier)

Symbolic label for a language entity or construct

Value

Storable quantity associated with a name

Location

Memory address where a value is stored

Attribute

Property that determines the meaning of a name (e.g., type, value)

Binding

Process of associating an attribute with a name

Binding Time

Moment when a binding occurs

Static Binding

Binding that occurs before execution

Dynamic Binding

Binding that occurs during execution

Static Attribute

Attribute bound statically

Dynamic Attribute

Attribute bound dynamically

Predefined Identifier

Name defined by the language itself (e.g., true, false)

Symbol Table

Data structure mapping names to attributes

Lexical Analysis

Determines if a character string is a valid token

Syntax Analysis

Checks if a sequence of tokens forms a valid phrase

Static Semantic Analysis

Ensures names conform to their declared attributes

Declaration

Statement that introduces a name and binds attributes

Definition

Declaration that binds all potential attributes

Prototype

Function declaration specifying type but not implementation

Block

Sequence of declarations followed by statements

Compound Statement

Block used as a single statement (e.g., in C)

Local Declaration

Declaration within a block

Nonlocal Declaration

Declaration from an enclosing block

Lexical Address

Pair of level number and offset identifying a name

Scope

Region of a program where a binding is valid

Lexical Scope

Scope determined by block structure

Declaration-Before-Use Rule

In C, a name's scope starts at its declaration

Scope Hole

Region where a global name is shadowed by a local one

Shadowing

Local declaration hides a nonlocal one

Visibility

Region where a name's binding is accessible

Insertion

Adding a name and its attributes to the symbol table

Lookup

Retrieving attributes for a name from the symbol table

Deletion

Removing a name's binding from the symbol table

Static Scoping

Bindings determined at compile time

Dynamic Scoping

Bindings determined at runtime

Overloading

Using the same name for multiple functions or operators

Overload Resolution

Choosing the correct function based on context

Calling Context

Information used to resolve overloaded functions

Operator Overloading

Defining multiple meanings for built-in operators

Function Overloading

Defining multiple functions with the same name but different parameters

Environment

Maps names to locations

Static Allocation

Memory assigned at load time

Dynamic Allocation

Memory assigned during execution

Activation

A function call

Activation Record

Memory allocated for a function call

Lifetime (Extent)

Duration an object exists in memory

Pointer

Variable storing the address of another object

Heap

Memory area for dynamic allocation

Storage Class

Type of allocation (static, automatic, dynamic)

Variable

Object whose value can change during execution

Assignment Statement

Updates a variable's value

L-Value

Refers to a variable's location

R-Value

Refers to a variable's value

Assignment by Sharing

Copies location, not value

Assignment by Cloning

Copies value into a new location

Value Semantics

Standard assignment behavior

Reference Semantics

Assignment using shared locations (pointers)

Constant

Entity with a fixed value

Literal

Direct representation of a value (e.g., 42, 'a')

Manifest Constant

Named literal

Compile-Time Constant

Value known at compile time

Static Constant

Value known at load time

Dynamic Constant

Value computed during execution

Alias

Two names bound to the same object

Side Effect

Change in state that persists beyond a statement

Dangling Reference

Pointer to a deallocated object

Garbage

Allocated memory that is no longer accessible

Garbage Collection

Automatic reclamation of unused memory

Struct

User-defined type containing fields with their own declarations

Struct Symbol Table

Local symbol table embedded in a struct

Scope Resolution Operator (

:): Used in C++ to access global variables shadowed by locals

Named Scope

A scoping unit with its own symbol table (e.g., Ada packages, C++ namespaces)

Symbol Table Stack

Layered structure of symbol tables for nested scopes

Search Path

Order in which symbol tables are searched for a name

Overloaded Name

Same name used for different constructs (e.g., type, function, variable)

Automatic Conversion

Implicit type conversion during overload resolution

Semantic Difference

Difference in meaning; operators and functions have none, only syntactic difference

Struct Field Access

Using dot notation to access fields within a struct

Struct Deletion

Struct's symbol table deleted only when the struct itself is deleted

Recursive Declaration

Declaration that refers to itself (e.g., recursive functions)

Scope of Function Name

Must begin before the function body to allow recursion

Dynamic Scope Output

Output affected by runtime bindings

Lexical Scope Output

Output determined by static bindings

Symbol Table Complexity

Increases with dynamic scoping and nested structures

Interpreter Environment

Runtime structure for managing dynamic bindings

Class/Package/Module

Scoping units in object-oriented and modular languages

Ada Scope

Named block with its own symbol table

Java Overloading

Allows same name for type, function, and variable

C++ Operator Overloading

Allows built-in operators to be overloaded with fixed syntax rules

Function Call Ambiguity

Occurs when multiple overloads could match a call

Return Type Resolution

Used in Ada but ignored in C++ and Java

Dot Member Notation

Syntax for accessing struct fields

Execution Path

Determines bindings in dynamic scoping

Symbol Table Search

Begins in current scope and continues outward until name is found