YASM expression interface. More...

Data Structures
struct	yasm_expr__item
	Expression item. More...
struct	yasm_expr
	Expression. More...
Defines
#define	YASM_LIB_DECL
#define	yasm_expr_create_tree(l, o, r, i) yasm_expr_create ((o), yasm_expr_expr(l), yasm_expr_expr(r), i)
	Create a new expression tree e=l op r.
#define	yasm_expr_create_branch(o, r, i) yasm_expr_create ((o), yasm_expr_expr(r), (yasm_expr__item *)NULL, i)
	Create a new expression branch e=op r.
#define	yasm_expr_create_ident(r, i) yasm_expr_create (YASM_EXPR_IDENT, (r), (yasm_expr__item *)NULL, i)
	Create a new expression identity e=r.
#define	yasm_expr_simplify(e, cbd) yasm_expr__level_tree(e, 1, 1, 1, cbd, NULL, NULL)
	Simplify an expression as much as possible.
Typedefs
typedef enum yasm_expr__type	yasm_expr__type
	Type of an expression item.
typedef struct yasm_expr__item	yasm_expr__item
	Expression item.
typedef yasm_expr (	yasm_expr_xform_func )(yasm_expr e, void d)
	Extra transformation function for yasm_expr__level_tree().
Enumerations
enum	yasm_expr__type { YASM_EXPR_NONE = 0, YASM_EXPR_REG = 1<<0, YASM_EXPR_INT = 1<<1, YASM_EXPR_SUBST = 1<<2, YASM_EXPR_FLOAT = 1<<3, YASM_EXPR_SYM = 1<<4, YASM_EXPR_PRECBC = 1<<5, YASM_EXPR_EXPR = 1<<6 }
	Type of an expression item. More...
Functions
YASM_LIB_DECL yasm_expr *	yasm_expr_create (yasm_expr_op op, yasm_expr__item a, yasm_expr__item b, unsigned long line)
	Create a new expression e=a op b.
YASM_LIB_DECL yasm_expr__item *	yasm_expr_precbc (yasm_bytecode *precbc)
	Create a new preceding-bytecode expression item.
YASM_LIB_DECL yasm_expr__item *	yasm_expr_sym (yasm_symrec *sym)
	Create a new symbol expression item.
YASM_LIB_DECL yasm_expr__item *	yasm_expr_expr (yasm_expr *e)
	Create a new expression expression item.
YASM_LIB_DECL yasm_expr__item *	yasm_expr_int (yasm_intnum *intn)
	Create a new intnum expression item.
YASM_LIB_DECL yasm_expr__item *	yasm_expr_float (yasm_floatnum *flt)
	Create a new floatnum expression item.
YASM_LIB_DECL yasm_expr__item *	yasm_expr_reg (uintptr_t reg)
	Create a new register expression item.
yasm_expr *	yasm_expr_copy (const yasm_expr *e)
	Duplicate an expression.
YASM_LIB_DECL void	yasm_expr_destroy (yasm_expr *e)
	Destroy (free allocated memory for) an expression.
YASM_LIB_DECL int	yasm_expr_is_op (const yasm_expr *e, yasm_expr_op op)
	Determine if an expression is a specified operation (at the top level).
YASM_LIB_DECL yasm_expr *	yasm_expr__level_tree (yasm_expr e, int fold_const, int simplify_ident, int simplify_reg_mul, int calc_bc_dist, yasm_expr_xform_func expr_xform_extra, void expr_xform_extra_data)
	Level an entire expression tree.
YASM_LIB_DECL yasm_expr *	yasm_expr_extract_deep_segoff (yasm_expr **ep)
	Extract the segment portion of an expression containing SEG:OFF, leaving the offset.
YASM_LIB_DECL yasm_expr *	yasm_expr_extract_segoff (yasm_expr **ep)
	Extract the segment portion of a SEG:OFF expression, leaving the offset.
YASM_LIB_DECL yasm_expr *	yasm_expr_extract_wrt (yasm_expr **ep)
	Extract the right portion (y) of a x WRT y expression, leaving the left portion (x).
YASM_LIB_DECL yasm_intnum *	yasm_expr_get_intnum (yasm_expr **ep, int calc_bc_dist)
	Get the integer value of an expression if it's just an integer.
YASM_LIB_DECL const yasm_symrec *	yasm_expr_get_symrec (yasm_expr **ep, int simplify)
	Get the symbol value of an expression if it's just a symbol.
YASM_LIB_DECL const uintptr_t *	yasm_expr_get_reg (yasm_expr **ep, int simplify)
	Get the register value of an expression if it's just a register.
YASM_LIB_DECL void	yasm_expr_print (const yasm_expr e, FILE f)
	Print an expression.
unsigned int	yasm_expr_size (const yasm_expr *e)
	Return the size of an expression, if the user provided it.
const char *	yasm_expr_segment (const yasm_expr *e)
	Return the segment of an expression, if the user provided it.
YASM_LIB_DECL int	yasm_expr__traverse_leaves_in_const (const yasm_expr e, void d, int(func)(const yasm_expr__item ei, void *d))
	Traverse over expression tree in order (const version).
YASM_LIB_DECL int	yasm_expr__traverse_leaves_in (yasm_expr e, void d, int(func)(yasm_expr__item ei, void *d))
	Traverse over expression tree in order.
YASM_LIB_DECL void	yasm_expr__order_terms (yasm_expr *e)
	Reorder terms of e into canonical order.
YASM_LIB_DECL yasm_expr *	yasm_expr__copy_except (const yasm_expr *e, int except)
	Copy entire expression EXCEPT for index "except" at top level only.
YASM_LIB_DECL int	yasm_expr__contains (const yasm_expr *e, yasm_expr__type t)
	Test if expression contains an item.
YASM_LIB_DECL int	yasm_expr__bc_dist_subst (yasm_expr *ep, void cbd, void(callback)(unsigned int subst, yasm_bytecode precbc, yasm_bytecode precbc2, void cbd))
	Transform symrec-symrec terms in expression into YASM_EXPR_SUBST items.
YASM_LIB_DECL int	yasm_expr__subst (yasm_expr e, unsigned int num_items, const yasm_expr__item items)
	Substitute items into expr YASM_EXPR_SUBST items (by index).

Detailed Description

YASM expression interface.

Definition in file expr.h.

Define Documentation

#define yasm_expr_create_branch	(	o,
		r,
		i
	)	yasm_expr_create ((o), yasm_expr_expr(r), (yasm_expr__item *)NULL, i)

Create a new expression branch e=op r.

Parameters:

o	operation
r	expression for right side of new expression
i	line index

Returns:: Newly allocated expression.

Definition at line 152 of file expr.h.

#define yasm_expr_create_ident	(	r,
		i
	)	yasm_expr_create (YASM_EXPR_IDENT, (r), (yasm_expr__item *)NULL, i)

Create a new expression identity e=r.

Parameters:

r	expression for identity within new expression
i	line index

Returns:: Newly allocated expression.

Definition at line 160 of file expr.h.

#define yasm_expr_create_tree	(	l,
		o,
		r,
		i
	)	yasm_expr_create ((o), yasm_expr_expr(l), yasm_expr_expr(r), i)

Create a new expression tree e=l op r.

Parameters:

l	expression for left side of new expression
o	operation
r	expression for right side of new expression
i	line index

Returns:: Newly allocated expression.

Definition at line 143 of file expr.h.

#define yasm_expr_simplify	(	e,
		cbd
	)	yasm_expr__level_tree(e, 1, 1, 1, cbd, NULL, NULL)

Simplify an expression as much as possible.

Eliminates extraneous branches and simplifies integer-only subexpressions. Simplified version of yasm_expr__level_tree().

Parameters:

e	expression
cbd	if distance between bytecodes should be calculated

Returns:: Simplified expression.

Definition at line 222 of file expr.h.

Typedef Documentation

typedef struct yasm_expr__item yasm_expr__item

Expression item.

typedef enum yasm_expr__type yasm_expr__type

Type of an expression item.

Types are listed in canonical sorting order. See expr_order_terms(). Note YASM_EXPR_PRECBC must be used carefully (in a-b pairs), as only symrecs can become the relative term in a yasm_value.

typedef yasm_expr*(* yasm_expr_xform_func)(yasm_expr *e,void *d)

Extra transformation function for yasm_expr__level_tree().

Parameters:

e	expression being simplified
d	data provided as expr_xform_extra_data to yasm_expr__level_tree()

Returns:: Transformed e.

Definition at line 194 of file expr.h.

Enumeration Type Documentation

enum yasm_expr__type

Type of an expression item.

Types are listed in canonical sorting order. See expr_order_terms(). Note YASM_EXPR_PRECBC must be used carefully (in a-b pairs), as only symrecs can become the relative term in a yasm_value.

Enumerator:

YASM_EXPR_NONE	Nothing.
YASM_EXPR_REG	Register.
YASM_EXPR_INT	Integer value.
YASM_EXPR_SUBST	Substitution placeholder.
YASM_EXPR_FLOAT	Floating point value.
YASM_EXPR_SYM	Symbol.
YASM_EXPR_PRECBC	Direct bytecode ref (rather than via sym)
YASM_EXPR_EXPR	Subexpression.

Definition at line 42 of file expr.h.

Function Documentation

YASM_LIB_DECL int yasm_expr__bc_dist_subst	(	yasm_expr **	ep,
		void *	cbd,
		void()(unsigned int subst, yasm_bytecode precbc, yasm_bytecode precbc2, void cbd)	callback
	)

Transform symrec-symrec terms in expression into YASM_EXPR_SUBST items.

Calls the callback function for each symrec-symrec term.

Parameters:

ep	expression (pointer to)
cbd	callback data passed to callback function
callback	callback function: given subst index for bytecode pair, bytecode pair (bc2-bc1), and cbd (callback data)

Returns:: Number of transformations made.

YASM_LIB_DECL int yasm_expr__contains	(	const yasm_expr *	e,
		yasm_expr__type	t
	)

Test if expression contains an item.

Searches recursively into subexpressions.

Parameters:

e	expression
t	type of item to look for

Returns:: Nonzero if expression contains an item of type t, zero if not.

YASM_LIB_DECL yasm_expr* yasm_expr__copy_except	(	const yasm_expr *	e,
		int	except
	)

Copy entire expression EXCEPT for index "except" at *top level only*.

Parameters:

e	expression
except	term index not to copy; -1 to copy all terms

Returns:: Newly allocated copy of expression.

YASM_LIB_DECL yasm_expr* yasm_expr__level_tree	(	yasm_expr *	e,
		int	fold_const,
		int	simplify_ident,
		int	simplify_reg_mul,
		int	calc_bc_dist,
		yasm_expr_xform_func	expr_xform_extra,
		void *	expr_xform_extra_data
	)

Level an entire expression tree.

Parameters:

e	expression
fold_const	enable constant folding if nonzero
simplify_ident	simplify identities
simplify_reg_mul	simplify REG*1 identities
calc_bc_dist	nonzero if distances between bytecodes should be calculated, 0 if they should be left intact
expr_xform_extra	extra transformation function
expr_xform_extra_data	data to pass to expr_xform_extra

Returns:: Leveled expression.

YASM_LIB_DECL void yasm_expr__order_terms ( yasm_expr * e )

Reorder terms of e into canonical order.

Only reorders if reordering doesn't change meaning of expression. (eg, doesn't reorder SUB). Canonical order: REG, INT, FLOAT, SYM, EXPR. Multiple terms of a single type are kept in the same order as in the original expression.

Parameters:

e	expression

Note:: Only performs reordering on *one* level (no recursion).

YASM_LIB_DECL int yasm_expr__subst	(	yasm_expr *	e,
		unsigned int	num_items,
		const yasm_expr__item *	items
	)

Substitute items into expr YASM_EXPR_SUBST items (by index).

Items are copied, so caller is responsible for freeing array of items.

Parameters:

e	expression
num_items	number of items in items array
items	items array

Returns:: 1 on error (index out of range).

YASM_LIB_DECL int yasm_expr__traverse_leaves_in	(	yasm_expr *	e,
		void *	d,
		int()(yasm_expr__item ei, void *d)	func
	)

Traverse over expression tree in order.

Calls func for each leaf (non-operation).

Parameters:

e	expression
d	data passed to each call to func
func	callback function

Returns:: Stops early (and returns 1) if func returns 1. Otherwise returns 0.

YASM_LIB_DECL int yasm_expr__traverse_leaves_in_const	(	const yasm_expr *	e,
		void *	d,
		int()(const yasm_expr__item ei, void *d)	func
	)

Traverse over expression tree in order (const version).

Calls func for each leaf (non-operation).

Parameters:

e	expression
d	data passed to each call to func
func	callback function

Returns:: Stops early (and returns 1) if func returns 1. Otherwise returns 0.

yasm_expr* yasm_expr_copy ( const yasm_expr * e )

Duplicate an expression.

Parameters:

e	expression

Returns:: Newly allocated expression identical to e.

YASM_LIB_DECL yasm_expr* yasm_expr_create	(	yasm_expr_op	op,
		yasm_expr__item *	a,
		yasm_expr__item *	b,
		unsigned long	line
	)

Create a new expression e=a op b.

Parameters:

op	operation
a	expression item a
b	expression item b (optional depending on op)
line	virtual line (where expression defined)

Returns:: Newly allocated expression.

YASM_LIB_DECL void yasm_expr_destroy ( yasm_expr * e )

Destroy (free allocated memory for) an expression.

Parameters:

e	expression

YASM_LIB_DECL yasm_expr__item* yasm_expr_expr ( yasm_expr * e )

Create a new expression expression item.

Parameters:

e	expression

Returns:: Newly allocated expression item.

YASM_LIB_DECL yasm_expr* yasm_expr_extract_deep_segoff ( yasm_expr ** ep )

Extract the segment portion of an expression containing SEG:OFF, leaving the offset.

Parameters:

ep	expression (pointer to)

Returns:: NULL if unable to extract a segment (expr does not contain a YASM_EXPR_SEGOFF operator), otherwise the segment expression. The input expression is modified such that on return, it's the offset expression.

YASM_LIB_DECL yasm_expr* yasm_expr_extract_segoff ( yasm_expr ** ep )

Extract the segment portion of a SEG:OFF expression, leaving the offset.

Parameters:

ep	expression (pointer to)

Returns:: NULL if unable to extract a segment (YASM_EXPR_SEGOFF not the top-level operator), otherwise the segment expression. The input expression is modified such that on return, it's the offset expression.

YASM_LIB_DECL yasm_expr* yasm_expr_extract_wrt ( yasm_expr ** ep )

Extract the right portion (y) of a x WRT y expression, leaving the left portion (x).

Parameters:

ep	expression (pointer to)

Returns:: NULL if unable to extract (YASM_EXPR_WRT not the top-level operator), otherwise the right side of the WRT expression. The input expression is modified such that on return, it's the left side of the WRT expression.

YASM_LIB_DECL yasm_expr__item* yasm_expr_float ( yasm_floatnum * flt )

Create a new floatnum expression item.

Parameters:

flt floatnum

Returns:: Newly allocated expression item.

YASM_LIB_DECL yasm_intnum* yasm_expr_get_intnum	(	yasm_expr **	ep,
		int	calc_bc_dist
	)

Get the integer value of an expression if it's just an integer.

Parameters:

ep	expression (pointer to)
calc_bc_dist	nonzero if distances between bytecodes should be calculated, 0 if NULL should be returned in this case

Returns:: NULL if the expression is too complex (contains anything other than integers, ie floats, non-valued labels, registers); otherwise the intnum value of the expression.

YASM_LIB_DECL const uintptr_t* yasm_expr_get_reg	(	yasm_expr **	ep,
		int	simplify
	)

Get the register value of an expression if it's just a register.

Parameters:

ep	expression (pointer to)
simplify	if nonzero, simplify the expression first

Returns:: NULL if the expression is too complex; otherwise the register value of the expression.

YASM_LIB_DECL const yasm_symrec* yasm_expr_get_symrec	(	yasm_expr **	ep,
		int	simplify
	)

Get the symbol value of an expression if it's just a symbol.

Parameters:

ep	expression (pointer to)
simplify	if nonzero, simplify the expression first

Returns:: NULL if the expression is too complex; otherwise the symbol value of the expression.

YASM_LIB_DECL yasm_expr__item* yasm_expr_int ( yasm_intnum * intn )

Create a new intnum expression item.

Parameters:

intn intnum

Returns:: Newly allocated expression item.

YASM_LIB_DECL int yasm_expr_is_op	(	const yasm_expr *	e,
		yasm_expr_op	op
	)

Determine if an expression is a specified operation (at the top level).

Parameters:

e	expression
op	operator

Returns:: Nonzero if the expression was the specified operation at the top level, zero otherwise.

YASM_LIB_DECL yasm_expr__item* yasm_expr_precbc ( yasm_bytecode * precbc )

Create a new preceding-bytecode expression item.

Parameters:

precbc preceding bytecode

Returns:: Newly allocated expression item.

YASM_LIB_DECL void yasm_expr_print	(	const yasm_expr *	e,
		FILE *	f
	)

Print an expression.

For debugging purposes.

Parameters:

e	expression
f	file

YASM_LIB_DECL yasm_expr__item* yasm_expr_reg ( uintptr_t reg )

Create a new register expression item.

Parameters:

reg register

Returns:: Newly allocated expression item.

const char* yasm_expr_segment ( const yasm_expr * e )

Return the segment of an expression, if the user provided it.

Parameters:

e	expression

unsigned int yasm_expr_size ( const yasm_expr * e )

Return the size of an expression, if the user provided it.

Parameters:

e	expression

YASM_LIB_DECL yasm_expr__item* yasm_expr_sym ( yasm_symrec * sym )

Create a new symbol expression item.

Parameters:

sym symbol

Returns:: Newly allocated expression item.

libyasm/expr.h File Reference

Data Structures

Defines

Typedefs

Enumerations

Functions

Detailed Description

Define Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation