libyasm/value.h File Reference

YASM value interface. More...

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Functions
YASM_LIB_DECL void	yasm_value_initialize (yasm_value *value, yasm_expr *e, unsigned int size)
	Initialize a yasm_value with just an expression.
YASM_LIB_DECL void	yasm_value_init_sym (yasm_value *value, yasm_symrec *sym, unsigned int size)
	Initialize a yasm_value with just a symrec.
YASM_LIB_DECL void	yasm_value_init_copy (yasm_value *value, const yasm_value *orig)
	Initialize a yasm_value as a copy of another yasm_value.
YASM_LIB_DECL void	yasm_value_delete (yasm_value *value)
	Frees any memory inside value; does not free value itself.
YASM_LIB_DECL void	yasm_value_set_curpos_rel (yasm_value *value, yasm_bytecode *bc, unsigned int ip_rel)
	Set a value to be relative to the current assembly position rather than relative to the section start.
YASM_LIB_DECL int	yasm_value_finalize (yasm_value *value, yasm_bytecode *precbc)
	Perform yasm_value_finalize_expr() on a value that already exists from being initialized with yasm_value_initialize().
YASM_LIB_DECL int	yasm_value_finalize_expr (yasm_value *value, yasm_expr *e, yasm_bytecode *precbc, unsigned int size)
	Break a yasm_expr into a yasm_value constituent parts.
YASM_LIB_DECL yasm_intnum *	yasm_value_get_intnum (yasm_value *value, yasm_bytecode *bc, int calc_bc_dist)
	Get value if absolute or PC-relative section-local relative.
YASM_LIB_DECL int	yasm_value_output_basic (yasm_value *value, unsigned char *buf, size_t destsize, yasm_bytecode *bc, int warn, yasm_arch *arch)
	Output value if constant or PC-relative section-local.
YASM_LIB_DECL void	yasm_value_print (const yasm_value *value, FILE *f, int indent_level)
	Print a value.

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Detailed Description

YASM value interface.

Definition in file value.h.

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Function Documentation

YASM_LIB_DECL void yasm_value_delete

(

yasm_value *

value

)

Frees any memory inside value; does not free value itself.

Parameters:

value

value

YASM_LIB_DECL int yasm_value_finalize	(	yasm_value *	value,
		yasm_bytecode *	precbc
	)

Perform yasm_value_finalize_expr() on a value that already exists from being initialized with yasm_value_initialize().

Parameters:

	value	value
	precbc	previous bytecode to bytecode containing value

Returns:

Nonzero if value could not be split.

YASM_LIB_DECL int yasm_value_finalize_expr	(	yasm_value *	value,
		yasm_expr *	e,
		yasm_bytecode *	precbc,
		unsigned int	size
	)

Break a yasm_expr into a yasm_value constituent parts.

Extracts the relative portion of the value, SEG and WRT portions, and top-level right shift, if any. Places the remaining expr into the absolute portion of the value. Essentially a combination of yasm_value_initialize() and yasm_value_finalize(). First expands references to symrecs in absolute sections by expanding with the absolute section start plus the symrec offset within the absolute section.

Parameters:

	value	value to store split portions into
	e	expression input
	precbc	previous bytecode to bytecode containing expression
	size	value size (in bits)

Returns:

Nonzero if the expr could not be split into a value for some reason (e.g. the relative portion was not added, but multiplied, etc).

Warning:

Do not use e after this call. Even if an error is returned, e is stored into value.

Note:

This should only be called after the parse is complete. Calling before the parse is complete will usually result in an error return.

YASM_LIB_DECL yasm_intnum* yasm_value_get_intnum	(	yasm_value *	value,
		yasm_bytecode *	bc,
		int	calc_bc_dist
	)

Get value if absolute or PC-relative section-local relative.

Returns NULL otherwise.

Parameters:

	value	value
	bc	current bytecode (for PC-relative calculation); if NULL, NULL is returned for PC-relative values.
	calc_bc_dist	if nonzero, calculates bytecode distances in absolute portion of value

Note:

Adds in value.rel (correctly) if PC-relative and in the same section as bc (and there is no WRT or SEG).

Returns:

Intnum if can be resolved to integer value, otherwise NULL.

YASM_LIB_DECL void yasm_value_init_copy	(	yasm_value *	value,
		const yasm_value *	orig
	)

Initialize a yasm_value as a copy of another yasm_value.

Any expressions within orig are copied, so it's safe to delete the copy.

Parameters:

	value	value (copy to create)
	orig	original value

YASM_LIB_DECL void yasm_value_init_sym	(	yasm_value *	value,
		yasm_symrec *	sym,
		unsigned int	size
	)

Initialize a yasm_value with just a symrec.

No processing is performed, the symrec is simply stuck into value.rel and the other fields are initialized.

Parameters:

	value	value to be initialized
	sym	symrec
	size	value size (in bits)

YASM_LIB_DECL void yasm_value_initialize	(	yasm_value *	value,
		yasm_expr *	e,
		unsigned int	size
	)

Initialize a yasm_value with just an expression.

No processing is performed, the expression is simply stuck into value.abs and the other fields are initialized. Use yasm_expr_extract_value() to perform "smart" processing into a yasm_value. This function is intended for use during parsing simply to ensure all fields of the value are initialized; after the parse is complete, yasm_value_extract() should be called to finalize the value. The value defaults to unsigned.

Parameters:

	value	value to be initialized
	e	expression (kept)
	size	value size (in bits)

YASM_LIB_DECL int yasm_value_output_basic	(	yasm_value *	value,
		unsigned char *	buf,
		size_t	destsize,
		yasm_bytecode *	bc,
		int	warn,
		yasm_arch *	arch
	)

Output value if constant or PC-relative section-local.

This should be used from objfmt yasm_output_value_func() functions. functions.

Parameters:

	value	value
	buf	buffer for byte representation
	destsize	destination size (in bytes)
	bc	current bytecode (usually passed into higher-level calling function)
	warn	enables standard warnings: zero for none; nonzero for overflow/underflow floating point and integer warnings
	arch	architecture

Note:

Adds in value.rel (correctly) if PC-relative and in the same section as bc (and there is no WRT or SEG); if this is not the desired behavior, e.g. a reloc is needed in this case, don't use this function!

Returns:

0 if no value output due to value needing relocation; 1 if value output; -1 if error.

YASM_LIB_DECL void yasm_value_print	(	const yasm_value *	value,
		FILE *	f,
		int	indent_level
	)

Print a value.

For debugging purposes.

Parameters:

	value	value
	indent_level	indentation level
	f	file

YASM_LIB_DECL void yasm_value_set_curpos_rel	(	yasm_value *	value,
		yasm_bytecode *	bc,
		unsigned int	ip_rel
	)

Set a value to be relative to the current assembly position rather than relative to the section start.

Parameters:

	value	value
	bc	bytecode containing value
	ip_rel	if nonzero, indicates IP-relative data relocation, sometimes used to generate special relocations

Note:

If value is just an absolute value, will get an absolute symrec to reference to (via bc's symbol table).

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