typecheck.h File Reference

Typechecking identifiers and expression. More...

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Macros
#define	T_ERR   -1
#define	T_ARRAYOF   0x20
	array flag
#define	T_STRICT   0x40
#define	T_PARAM   0x80
	a parameter type flag for pint/... etc
#define	T_INT   0x1
	an integer (data or parameter type)
#define	T_REAL   0x2
	a real number
#define	T_BOOL   0x4
	a Boolean (data or parameter)
#define	T_PROC   0x5
	a process
#define	T_CHAN   0x6
	a channel
#define	T_DATA_INT   0x7
	an integer within a channel
#define	T_DATA_BOOL   0x8
	a bool within a channel
#define	T_SELF   0x9
	special type, "self"
#define	T_DATA   0xa
	a structure
#define	T_DATA_ENUM   0xb
	an enum that is not an int
#define	T_PTYPE   0x10
	used when the expression is a type
#define	T_MASK   0x1f
	mask for the list of options
#define	T_FIXBASETYPE(x)   ((((x) & T_MASK) == T_DATA_BOOL) ? T_BOOL : ((((x) & T_MASK) == T_DATA_INT) ? T_INT : ((x) & T_MASK)))
#define	T_BASETYPE(x)   ((x) & T_MASK)
#define	T_BASETYPE_ISNUM(x)   (T_FIXBASETYPE (x) == T_INT || T_BASETYPE (x) == T_REAL)
#define	T_BASETYPE_INT(x)   (T_FIXBASETYPE(x) == T_INT)
#define	T_BASETYPE_BOOL(x)   (T_FIXBASETYPE(x) == T_BOOL)
#define	T_BASETYPE_ISINTBOOL(x)   (T_BASETYPE_INT(x) || T_BASETYPE_BOOL(x))

Functions
int	act_type_expr (Scope *s, Expr *e, int *width, int only_chan=0)
int	act_type_var (Scope *s, ActId *id, InstType **xit)
int	act_type_chan (Scope *sc, Chan *ch, int is_send, Expr *e, ActId *id, int override_id)
int	act_type_conn (Scope *, ActId *, AExpr *)
int	act_type_conn (Scope *, AExpr *, AExpr *)
int	type_connectivity_check (InstType *lhs, InstType *rhs, int skip_last_array=0)
int	type_chp_check_assignable (InstType *lhs, InstType *rhs)
InstType *	act_expr_insttype (Scope *s, Expr *e, int *islocal, int only_chan)
InstType *	act_actual_insttype (Scope *s, ActId *id, int *islocal)
void	type_set_position (int l, int c, char *n)
const char *	act_type_errmsg (void)
void	typecheck_err (const char *s,...)

Detailed Description

Typechecking identifiers and expression.

The typechecking functions return an integer code. This code is T_ERR on an error, or a flag that is used to summarize the type of the result.

The function act_type_errmsg() can be used to get a string that corresponds to a more verbose message corresponding to the last error that was encountered during type-checking.

Macro Definition Documentation

T_ARRAYOF

#define T_ARRAYOF   0x20

array flag

T_BASETYPE

#define T_BASETYPE

(

x

)

((x) & T_MASK)

Used to extract the type case minus any flags (the "base type")

T_BASETYPE_BOOL

#define T_BASETYPE_BOOL

(

x

)

(T_FIXBASETYPE(x) == T_BOOL)

Check if the processed base type is a bool

T_BASETYPE_INT

#define T_BASETYPE_INT

(

x

)

(T_FIXBASETYPE(x) == T_INT)

Check if the processed base type is an int

T_BASETYPE_ISINTBOOL

#define T_BASETYPE_ISINTBOOL

(

x

)

(T_BASETYPE_INT(x) || T_BASETYPE_BOOL(x))

Check if the processed base type is an integer or a boolean. This means it could be a chan(bool) or a chan(int) as well.

T_BASETYPE_ISNUM

#define T_BASETYPE_ISNUM

(

x

)

(T_FIXBASETYPE (x) == T_INT || T_BASETYPE (x) == T_REAL)

Check if the base type is an integer or real number, i.e. a numeric value

T_BOOL

#define T_BOOL   0x4

a Boolean (data or parameter)

T_CHAN

#define T_CHAN   0x6

a channel

T_DATA

#define T_DATA   0xa

a structure

T_DATA_BOOL

#define T_DATA_BOOL   0x8

a bool within a channel

T_DATA_ENUM

#define T_DATA_ENUM   0xb

an enum that is not an int

T_DATA_INT

#define T_DATA_INT   0x7

an integer within a channel

T_ERR

#define T_ERR   -1

return if the checking function returns an error

T_FIXBASETYPE

#define T_FIXBASETYPE

(

x

)

((((x) & T_MASK) == T_DATA_BOOL) ? T_BOOL : ((((x) & T_MASK) == T_DATA_INT) ? T_INT : ((x) & T_MASK)))

Used to process return types by converting T_DATA_BOOL to T_BOOL, and T_DATA_INT to T_INT.

T_INT

#define T_INT   0x1

an integer (data or parameter type)

T_MASK

#define T_MASK   0x1f

mask for the list of options

T_PARAM

#define T_PARAM   0x80

a parameter type flag for pint/... etc

T_PROC

#define T_PROC   0x5

a process

T_PTYPE

#define T_PTYPE   0x10

used when the expression is a type

T_REAL

#define T_REAL   0x2

a real number

T_SELF

#define T_SELF   0x9

special type, "self"

T_STRICT

#define T_STRICT   0x40

a port parameter flag that is in the "strict" list... i.e. not optional, i.e. before the vertical bar (NOT USED)

Function Documentation

act_actual_insttype()

InstType * act_actual_insttype	(	Scope *	s,
		ActId *	id,
		int *	islocal
	)

Returns the actual type of the identifier.

Parameters

s	is the scope
id	is the identifier
islocal	is used to return 1 if the identifier is only accessible within the local scope specified, 0 otherwise

Returns

the type of the identifier (NULL if not found)

act_expr_insttype()

InstType * act_expr_insttype	(	Scope *	s,
		Expr *	e,
		int *	islocal,
		int	only_chan
	)

Returns the actual type of the expression. only_chan is the same flag as act_type_expr(), and can be 0, 1, 2, or 3.

Parameters

s	is the scope
e	is the expression
islocal	is used to return 1 if all identifiers within this expression are local to the scope and cannot be accessed from outside the scope, 0 otherwise
only_chan	is the same as the only_chan flag for act_type_expr()

Returns

the InstType for the expression (if successful), NULL otherwise.

act_type_chan()

int act_type_chan	(	Scope *	sc,
		Chan *	ch,
		int	is_send,
		Expr *	e,
		ActId *	id,
		int	override_id
	)

Used to type-check a channel operation. The channel operation is of one of the following forms: ch!e ch?v ch!e?v ch?v!e

An identifier could also be of the form bool(v) or int(v), which is used to implicitly convert the identifier type from int to bool or bool to int. The override_id flag is used for this purpose.

Parameters

sc	is the scope in which the type-checking is performed
ch	is the channel type
is_send	is 1 for a send operation, 0 for a receive operation
e	is the (optional) expression being sent
id	is the (optional) identifer for the receive operation
override_id	is -1 if int/bool overrides are absent, 0 for bool(.), and 1 for int(.)

Returns

1 on success, 0 on error

act_type_conn() [1/2]

int act_type_conn	(	Scope *	,
		ActId *	,
		AExpr *
	)

Used to type-check a connection between an identifier and an array expression

Returns

1 on success, 0 on error

act_type_conn() [2/2]

int act_type_conn	(	Scope *	,
		AExpr *	,
		AExpr *
	)

Used to type-check a connection between two array expressions

Returns

1 on success, 0 on error

act_type_errmsg()

const char * act_type_errmsg

(

void

)

Used to return the type-checking error message

Returns

error string from last recorded type-check error message

act_type_expr()

int act_type_expr	(	Scope *	s,
		Expr *	e,
		int *	width,
		int	only_chan = 0
	)

Typecheck an expression, and return the result type if the type-checking succeeds.

The only_chan flag is used to set the mode of the check.

• only_chan = 0 : normal expression, used for standard expression type checking.
• only_chan = 1 : the identifiers must always be channel types, and the type corresponds to the data values being communicated on the channels. This is used for dataflow checking.
• only_chan = 2 : permit both identifiers and channels. This is used for CHP expressions that can inspect the value pending on a channel.

Parameters

s	is the scope in which the type-checking is performed
e	is the expression
width	if non-NULL, this is used to return the bit-width of the result
only_chan	is a flag that determines valid identifiers.

Returns

a T_... flag that describes the result of checking

act_type_var()

int act_type_var	(	Scope *	s,
		ActId *	id,
		InstType **	xit
	)

Used to type-check a variable

Parameters

s	is the scope in which to peform the type-checking
id	is the variable to be checked
xit	is used to return the actual InstType * for the identifier, if xit is non-NULL

Returns

a T_... flag that describes the result of the checking

type_chp_check_assignable()

int type_chp_check_assignable	(	InstType *	lhs,
		InstType *	rhs
	)

This checks if a value with a type corresponding to the rhs can be assigned to one on the lhs in a CHP program

Parameters

lhs	is the left-hand side type: the type of the id
rhs	is the right-hand side type: the type of the expression

Returns

1 if they are assignable, 0 otherwise

type_connectivity_check()

int type_connectivity_check	(	InstType *	lhs,
		InstType *	rhs,
		int	skip_last_array = 0
	)

Used to check if two types can be connected to each other. If a type is an array type, then for unexpanded types this only checks that the number of dimensions are equal. For expanded types, it checks that the dimension sizes also match.

If skip_last_array is set to 1, this will skip checking the size of the first dimension.

Return values:

• 0 = they are not compatible
• 1 = they are compatible
• 2 = they are compatible, lhs is more specific
• 3 = they are compatible, rhs is more specific

Parameters

lhs	is the first type to check
rhs	is the second type to check
skip_last_array	is used to omit the first dimension check

Returns

the result of checking if the types can be connected to each other

type_set_position()

void type_set_position	(	int	l,
		int	c,
		char *	n
	)

Used to record the line, column, and file for error reporting

Parameters

l	is the line number
c	is the column number
n	is the file name

typecheck_err()

void typecheck_err	(	const char *	s,
			...
	)

Use this to set the type-checking error message that is later returned by act_type_errmsg()

Parameters

s	is the printf-style format string