symbol.h File Reference

Symbols, symbol tables, and static analysis errors. More...

#include "ast.h"
#include "visitor.h"

Go to the source code of this file.

Classes
struct	Symbol
	Single Decaf symbol. More...
struct	SymbolList
	Linked list of struct Symbol* elements. More...
struct	SymbolTable
	Stores symbol info for a single lexical scope. More...
struct	AnalysisError
	Static analysis error structure. More...
struct	ErrorList
	Linked list of AnalysisError* elements. More...

Typedefs
typedef struct Symbol	Symbol
	Single Decaf symbol.
typedef struct SymbolList	SymbolList
	Linked list of struct Symbol* elements.
typedef struct SymbolTable	SymbolTable
	Stores symbol info for a single lexical scope.
typedef struct AnalysisError	AnalysisError
	Static analysis error structure.
typedef struct ErrorList	ErrorList
	Linked list of AnalysisError* elements.

Functions
void	type_attr_print (void *value, FILE *output)
	Simple "print" function that prints an attribute value as a Decaf type.
void	symtable_attr_print (void *value, FILE *output)
	Function that prints a symbol table attribute using DOT formatting.
Symbol *	Symbol_new (const char *name, DecafType type)
	Create a new scalar symbol.
Symbol *	Symbol_new_array (const char *name, DecafType type, int length)
	Create a new array symbol.
Symbol *	Symbol_new_function (const char *name, DecafType return_type, ParameterList *parameters)
	Create a new function symbol.
void	Symbol_print (Symbol *symbol, FILE *output)
	Print simplified string representation.
void	Symbol_free (Symbol *symbol)
	Deallocate a symbol.
SymbolList *	SymbolList_new (void)
	Allocate and initialize a new, empty list.
void	SymbolList_add (SymbolList *list, struct Symbol *item)
	Add an item to the end of a list.
int	SymbolList_size (SymbolList *list)
	Look up the size of a list.
bool	SymbolList_is_empty (SymbolList *list)
	Test a list to see if it is empty.
void	SymbolList_free (SymbolList *list)
	Deallocate a list and any contained items.
SymbolTable *	SymbolTable_new (void)
	Create a new symbol table with no parent link.
SymbolTable *	SymbolTable_new_child (SymbolTable *parent)
	Create a new symbol table with a parent link.
void	SymbolTable_insert (SymbolTable *table, Symbol *symbol)
	Add a symbol to a table.
Symbol *	SymbolTable_lookup (SymbolTable *table, const char *name)
	Retrieve a symbol from a table.
void	SymbolTable_free (SymbolTable *table)
	Deallocate a symbol table.
Symbol *	lookup_symbol (ASTNode *node, const char *name)
	Look up a symbol in an AST.
NodeVisitor *	BuildSymbolTablesVisitor_new (void)
	Create a new visitor that builds symbol tables.
NodeVisitor *	PrintSymbolsVisitor_new (FILE *output)
	Create a new visitor that prints symbol tables.
ErrorList *	ErrorList_new (void)
	Allocate and initialize a new, empty list.
void	ErrorList_add (ErrorList *list, AnalysisError *item)
	Add an item to the end of a list.
int	ErrorList_size (ErrorList *list)
	Look up the size of a list.
bool	ErrorList_is_empty (ErrorList *list)
	Test a list to see if it is empty.
void	ErrorList_free (ErrorList *list)
	Deallocate a list and any contained items.
void	ErrorList_printf (ErrorList *list, const char *format,...)
	Add an error message to a list of errors using printf syntax.

Detailed Description

Symbols, symbol tables, and static analysis errors.

This module provides declarations for the symbol table and static analysis framework. The declarations in this file will be will be critical for Project 3 (static analysis) and 4 (code generation).

Typedef Documentation

Symbol

typedef struct Symbol Symbol

Single Decaf symbol.

Might represent a scalar variable, an array, or a formal function parameter.

SymbolTable

typedef struct SymbolTable SymbolTable

Stores symbol info for a single lexical scope.

Symbol tables are generated using a simple AST traversal algorithm, and are used during code generation to look up type and location information for individual symbols.

Function Documentation

BuildSymbolTablesVisitor_new()

NodeVisitor * BuildSymbolTablesVisitor_new

(

void

)

Create a new visitor that builds symbol tables.

Returns

Pointer to visitor structure

lookup_symbol()

Symbol * lookup_symbol	(	ASTNode *	node,
		const char *	name
	)

Look up a symbol in an AST.

The search has two phases: 1) searching AST nodes for a symbol table as a "symbolTable" attribute and following "parent" attributes as necessary (requires the links as set up by a SetParentVisitor), and 2) searching symbol tables for the given symbol name and following parent pointers as necessary.

Parameters

node	AST node to begin the search at
name	Name of symbol to find

Returns

The Symbol if found, otherwise NULL

PrintSymbolsVisitor_new()

NodeVisitor * PrintSymbolsVisitor_new

(

FILE *

output

)

Create a new visitor that prints symbol tables.

Parameters

output

File stream for the print output

Returns

Pointer to visitor structure

Symbol_new()

Symbol * Symbol_new	(	const char *	name,
		DecafType	type
	)

Create a new scalar symbol.

Parameters

name	Name in source code
type	Data type

Symbol_new_array()

Symbol * Symbol_new_array	(	const char *	name,
		DecafType	type,
		int	length
	)

Create a new array symbol.

Parameters

name	Name in source code
type	Data type
length	Array length

Symbol_new_function()

Symbol * Symbol_new_function	(	const char *	name,
		DecafType	return_type,
		ParameterList *	parameters
	)

Create a new function symbol.

Parameters

name	Name in source code
return_type	Function return type
parameters	List of formal parameter names and data types

SymbolTable_insert()

void SymbolTable_insert	(	SymbolTable *	table,
		Symbol *	symbol
	)

Add a symbol to a table.

Parameters

table	Symbol table to insert the symbol into
symbol	Symbol to insert

SymbolTable_lookup()

Symbol * SymbolTable_lookup	(	SymbolTable *	table,
		const char *	name
	)

Retrieve a symbol from a table.

Looks through parent tables if the symbol is not found in the local table.

Parameters

table	Symbol table to search
name	Name of symbol to find

Returns

The Symbol if found, otherwise NULL

SymbolTable_new_child()

SymbolTable * SymbolTable_new_child

(

SymbolTable *

parent

)

Create a new symbol table with a parent link.

Parameters

parent

Pointer to parent table