Yasm Assembler mainline development tree (ffmpeg 依赖)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

162 lines
6.9 KiB

/**
* \file libyasm/value.h
* \brief YASM value interface.
*
* \rcs
* $Id$
* \endrcs
*
* \license
* Copyright (C) 2006 Peter Johnson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* \endlicense
*/
#ifndef YASM_VALUE_H
#define YASM_VALUE_H
/** 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.
* \param value value to be initialized
* \param e expression (kept)
* \param size value size (in bits)
*/
void yasm_value_initialize(/*@out@*/ yasm_value *value,
/*@null@*/ /*@kept@*/ yasm_expr *e,
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.
* \param value value to be initialized
* \param sym symrec
* \param size value size (in bits)
*/
void yasm_value_init_sym(/*@out@*/ yasm_value *value,
/*@null@*/ yasm_symrec *sym, unsigned int size);
/** 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.
* \param value value (copy to create)
* \param orig original value
*/
void yasm_value_init_copy(yasm_value *value, const yasm_value *orig);
/** Frees any memory inside value; does not free value itself.
* \param value value
*/
void yasm_value_delete(yasm_value *value);
/** Set a value to be relative to the current assembly position rather than
* relative to the section start.
* \param value value
* \param bc bytecode containing value
* \param 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).
*/
void yasm_value_set_curpos_rel(yasm_value *value, yasm_bytecode *bc,
unsigned int ip_rel);
/** Perform yasm_value_finalize_expr() on a value that already exists from
* being initialized with yasm_value_initialize().
* \param value value
* \param precbc previous bytecode to bytecode containing value
* \return Nonzero if value could not be split.
*/
int yasm_value_finalize(yasm_value *value, /*@null@*/ yasm_bytecode *precbc);
/** 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.
* \param value value to store split portions into
* \param e expression input
* \param precbc previous bytecode to bytecode containing expression
* \param size value size (in bits)
* \return 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.
*/
int yasm_value_finalize_expr(/*@out@*/ yasm_value *value,
/*@null@*/ /*@kept@*/ yasm_expr *e,
/*@null@*/ yasm_bytecode *precbc,
unsigned int size);
/** Get value if absolute or PC-relative section-local relative. Returns NULL
* otherwise.
* \param value value
* \param bc current bytecode (for PC-relative calculation); if
* NULL, NULL is returned for PC-relative values.
* \param 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).
* \return Intnum if can be resolved to integer value, otherwise NULL.
*/
/*@null@*/ /*@only@*/ yasm_intnum *yasm_value_get_intnum
(yasm_value *value, /*@null@*/ yasm_bytecode *bc, int calc_bc_dist);
/** Output value if constant or PC-relative section-local. This should be
* used from objfmt yasm_output_value_func() functions.
* functions.
* \param value value
* \param buf buffer for byte representation
* \param destsize destination size (in bytes)
* \param bc current bytecode (usually passed into higher-level
* calling function)
* \param warn enables standard warnings: zero for none;
* nonzero for overflow/underflow floating point and
* integer warnings
* \param 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!
* \return 0 if no value output due to value needing relocation;
* 1 if value output; -1 if error.
*/
int yasm_value_output_basic
(yasm_value *value, /*@out@*/ unsigned char *buf, size_t destsize,
yasm_bytecode *bc, int warn, yasm_arch *arch);
/** Print a value. For debugging purposes.
* \param value value
* \param indent_level indentation level
* \param f file
*/
void yasm_value_print(const yasm_value *value, FILE *f, int indent_level);
#endif