Yasm Assembler mainline development tree (ffmpeg 依赖)
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/**
* \file libyasm/bytecode.h
* \brief YASM bytecode interface.
*
* \rcs
* $Id$
* \endrcs
*
* \license
* Copyright (C) 2001 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_BYTECODE_H
#define YASM_BYTECODE_H
/** An effective address. */
typedef struct yasm_effaddr yasm_effaddr;
/** Callbacks for effective address implementations. */
typedef struct yasm_effaddr_callback {
/** Destroy the effective address (freeing it).
* \param ea effective address
*/
void (*destroy) (/*@only@*/ yasm_effaddr *ea);
/** Print the effective address.
* \param ea effective address
* \param f file to output to
* \param indent_level indentation level
*/
void (*print) (const yasm_effaddr *ea, FILE *f, int indent_level);
} yasm_effaddr_callback;
/** An effective address. */
struct yasm_effaddr {
const yasm_effaddr_callback *callback; /**< callback functions */
yasm_value disp; /**< address displacement */
uintptr_t segreg; /**< segment register override (0 if none) */
unsigned char need_nonzero_len; /**< 1 if length of disp must be >0. */
unsigned char need_disp; /**< 1 if a displacement should be present
* in the output.
*/
unsigned char nosplit; /**< 1 if reg*2 should not be split into
* reg+reg. (0 if not)
*/
unsigned char strong; /**< 1 if effective address is *definitely*
* an effective address, e.g. in GAS if
* expr(,1) form is used vs. just expr.
*/
};
/** A data value (opaque type). */
typedef struct yasm_dataval yasm_dataval;
/** A list of data values (opaque type). */
typedef struct yasm_datavalhead yasm_datavalhead;
#ifdef YASM_LIB_INTERNAL
/*@reldef@*/ STAILQ_HEAD(yasm_datavalhead, yasm_dataval);
#endif
/** Get the displacement portion of an effective address.
* \param ea effective address
* \return Expression representing the displacement (read-only).
*/
/*@observer@*/ const yasm_expr *yasm_ea_get_disp(const yasm_effaddr *ea);
/** Set the length of the displacement portion of an effective address.
* The length is specified in bits.
* \param ea effective address
* \param len length in bits
*/
void yasm_ea_set_len(yasm_effaddr *ea, unsigned int len);
/** Set/clear nosplit flag of an effective address.
* The nosplit flag indicates (for architectures that support complex effective
* addresses such as x86) if various types of complex effective addresses can
* be split into different forms in order to minimize instruction length.
* \param ea effective address
* \param nosplit nosplit flag setting (0=splits allowed, nonzero=splits
* not allowed)
*/
void yasm_ea_set_nosplit(yasm_effaddr *ea, unsigned int nosplit);
/** Set/clear strong flag of an effective address.
* The strong flag indicates if an effective address is *definitely* an
* effective address. This is used in e.g. the GAS parser to differentiate
* between "expr" (which might or might not be an effective address) and
* "expr(,1)" (which is definitely an effective address).
* \param ea effective address
* \param strong strong flag setting (0=not strong, nonzero=strong)
*/
void yasm_ea_set_strong(yasm_effaddr *ea, unsigned int strong);
/** Set segment override for an effective address.
* Some architectures (such as x86) support segment overrides on effective
* addresses. A override of an override will result in a warning.
* \param ea effective address
* \param segreg segment register (0 if none)
*/
void yasm_ea_set_segreg(yasm_effaddr *ea, uintptr_t segreg);
/** Delete (free allocated memory for) an effective address.
* \param ea effective address (only pointer to it).
*/
void yasm_ea_destroy(/*@only@*/ yasm_effaddr *ea);
/** Print an effective address. For debugging purposes.
* \param f file
* \param indent_level indentation level
* \param ea effective address
*/
void yasm_ea_print(const yasm_effaddr *ea, FILE *f, int indent_level);
/** Set multiple field of a bytecode.
* A bytecode can be repeated a number of times when output. This function
* sets that multiple.
* \param bc bytecode
* \param e multiple (kept, do not free)
*/
void yasm_bc_set_multiple(yasm_bytecode *bc, /*@keep@*/ yasm_expr *e);
/** Create a bytecode containing data value(s).
* \param datahead list of data values (kept, do not free)
* \param size storage size (in bytes) for each data value
* \param append_zero append a single zero byte after each data value
* (if non-zero)
* \param arch architecture (optional); if provided, data items
* are directly simplified to bytes if possible
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_data
(yasm_datavalhead *datahead, unsigned int size, int append_zero,
/*@null@*/ yasm_arch *arch, unsigned long line);
/** Create a bytecode containing LEB128-encoded data value(s).
* \param datahead list of data values (kept, do not free)
* \param sign signedness (1=signed, 0=unsigned) of each data value
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_leb128
(yasm_datavalhead *datahead, int sign, unsigned long line);
/** Create a bytecode reserving space.
* \param numitems number of reserve "items" (kept, do not free)
* \param itemsize reserved size (in bytes) for each item
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_reserve
(/*@only@*/ yasm_expr *numitems, unsigned int itemsize,
unsigned long line);
/** Create a bytecode that includes a binary file verbatim.
* \param filename path to binary file (kept, do not free)
* \param start starting location in file (in bytes) to read data from
* (kept, do not free); may be NULL to indicate 0
* \param maxlen maximum number of bytes to read from the file (kept, do
* do not free); may be NULL to indicate no maximum
* \param linemap line mapping repository
* \param line virtual line (from yasm_linemap) for the bytecode
* \return Newly allocated bytecode.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_incbin
(/*@only@*/ char *filename, /*@only@*/ /*@null@*/ yasm_expr *start,
/*@only@*/ /*@null@*/ yasm_expr *maxlen, yasm_linemap *linemap,
unsigned long line);
/** Create a bytecode that aligns the following bytecode to a boundary.
* \param boundary byte alignment (must be a power of two)
* \param fill fill data (if NULL, code_fill or 0 is used)
* \param maxskip maximum number of bytes to skip
* \param code_fill code fill data (if NULL, 0 is used)
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
* \note The precedence on generated fill is as follows:
* - from fill parameter (if not NULL)
* - from code_fill parameter (if not NULL)
* - 0
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_align
(/*@keep@*/ yasm_expr *boundary, /*@keep@*/ /*@null@*/ yasm_expr *fill,
/*@keep@*/ /*@null@*/ yasm_expr *maxskip,
/*@null@*/ const unsigned char **code_fill, unsigned long line);
/** Create a bytecode that puts the following bytecode at a fixed section
* offset.
* \param start section offset of following bytecode
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_org
(unsigned long start, unsigned long line);
/** Create a bytecode that represents a single instruction.
* \param arch instruction's architecture
* \param insn_data data that identifies the type of instruction
* \param num_operands number of operands
* \param operands instruction operands (may be NULL if no operands)
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
* \note Keeps the list of operands; do not call yasm_ops_delete() after
* giving operands to this function.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_insn
(yasm_arch *arch, const uintptr_t insn_data[4], int num_operands,
/*@null@*/ yasm_insn_operands *operands, unsigned long line);
/** Create a bytecode that represents a single empty (0 length) instruction.
* This is used for handling solitary prefixes.
* \param arch instruction's architecture
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
*/
/*@only@*/ yasm_bytecode *yasm_bc_create_empty_insn(yasm_arch *arch,
unsigned long line);
/** Associate a prefix with an instruction bytecode.
* \param bc instruction bytecode
* \param prefix_data data the identifies the prefix
*/
void yasm_bc_insn_add_prefix(yasm_bytecode *bc,
const uintptr_t prefix_data[4]);
/** Associate a segment prefix with an instruction bytecode.
* \param bc instruction bytecode
* \param segreg data the identifies the segment register
*/
void yasm_bc_insn_add_seg_prefix(yasm_bytecode *bc, uintptr_t segreg);
/** Get the section that contains a particular bytecode.
* \param bc bytecode
* \return Section containing bc (can be NULL if bytecode is not part of a
* section).
*/
/*@dependent@*/ /*@null@*/ yasm_section *yasm_bc_get_section
(yasm_bytecode *bc);
#ifdef YASM_LIB_INTERNAL
/** Add to the list of symrecs that reference a bytecode. For symrec use
* only.
* \param bc bytecode
* \param sym symbol
*/
void yasm_bc__add_symrec(yasm_bytecode *bc, /*@dependent@*/ yasm_symrec *sym);
#endif
/** Delete (free allocated memory for) a bytecode.
* \param bc bytecode (only pointer to it); may be NULL
*/
void yasm_bc_destroy(/*@only@*/ /*@null@*/ yasm_bytecode *bc);
/** Print a bytecode. For debugging purposes.
* \param f file
* \param indent_level indentation level
* \param bc bytecode
*/
void yasm_bc_print(const yasm_bytecode *bc, FILE *f, int indent_level);
/** Finalize a bytecode after parsing.
* \param bc bytecode
* \param prev_bc bytecode directly preceding bc in a list of bytecodes
*/
void yasm_bc_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc);
/** Determine the distance between the starting offsets of two bytecodes.
* \param precbc1 preceding bytecode to the first bytecode
* \param precbc2 preceding bytecode to the second bytecode
* \return Distance in bytes between the two bytecodes (bc2-bc1), or NULL if
* the distance was indeterminate.
* \warning Only valid /after/ optimization.
*/
/*@null@*/ /*@only@*/ yasm_intnum *yasm_calc_bc_dist
(yasm_bytecode *precbc1, yasm_bytecode *precbc2);
/** Get the offset of the next bytecode (the next bytecode doesn't have to
* actually exist).
* \param precbc preceding bytecode
* \return Offset of the next bytecode in bytes.
* \warning Only valid /after/ optimization.
*/
unsigned long yasm_bc_next_offset(yasm_bytecode *precbc);
/** Add a dependent span for a bytecode.
* \param add_span_data add_span_data passed into bc_calc_len()
* \param bc bytecode containing span
* \param id non-zero identifier for span; may be any non-zero value
* if <0, expand is called for any change;
* if >0, expand is only called when exceeds threshold
* \param value dependent value for bytecode expansion
* \param neg_thres negative threshold for long/short decision
* \param pos_thres positive threshold for long/short decision
*/
typedef void (*yasm_bc_add_span_func)
(void *add_span_data, yasm_bytecode *bc, int id, const yasm_value *value,
long neg_thres, long pos_thres);
/** Resolve EQUs in a bytecode and calculate its minimum size.
* Generates dependent bytecode spans for cases where, if the length spanned
* increases, it could cause the bytecode size to increase.
* Any bytecode multiple is NOT included in the length or spans generation;
* this must be handled at a higher level.
* \param bc bytecode
* \param add_span function to call to add a span
* \param add_span_data extra data to be passed to add_span function
* \return 0 if no error occurred, nonzero if there was an error recognized
* (and output) during execution.
* \note May store to bytecode updated expressions and the short length.
*/
int yasm_bc_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
void *add_span_data);
/** Recalculate a bytecode's length based on an expanded span length.
* \param bc bytecode
* \param span span ID (as given to yasm_bc_add_span_func in
* yasm_bc_calc_len)
* \param old_val previous span value
* \param new_val new span value
* \param neg_thres negative threshold for long/short decision (returned)
* \param pos_thres postivie threshold for long/short decision (returned)
* \return 0 if bc no longer dependent on this span's length, negative if
* there was an error recognized (and output) during execution, and
* positive if bc size may increase for this span further based on the
* new negative and positive thresholds returned.
* \note May store to bytecode updated expressions and the updated length.
*/
int yasm_bc_expand(yasm_bytecode *bc, int span, long old_val, long new_val,
/*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres);
/** Convert a bytecode into its byte representation.
* \param bc bytecode
* \param buf byte representation destination buffer
* \param bufsize size of buf (in bytes) prior to call; size of the
* generated data after call
* \param gap if nonzero, indicates the data does not really need to
* exist in the object file; if nonzero, contents of buf
* are undefined [output]
* \param d data to pass to each call to output_value/output_reloc
* \param output_value function to call to convert values into their byte
* representation
* \param output_reloc function to call to output relocation entries
* for a single sym
* \return Newly allocated buffer that should be used instead of buf for
* reading the byte representation, or NULL if buf was big enough to
* hold the entire byte representation.
* \note Calling twice on the same bytecode may \em not produce the same
* results on the second call, as calling this function may result in
* non-reversible changes to the bytecode.
*/
/*@null@*/ /*@only@*/ unsigned char *yasm_bc_tobytes
(yasm_bytecode *bc, unsigned char *buf, unsigned long *bufsize,
/*@out@*/ int *gap, void *d, yasm_output_value_func output_value,
/*@null@*/ yasm_output_reloc_func output_reloc)
/*@sets *buf@*/;
/** Get the bytecode multiple value as an integer.
* \param bc bytecode
* \param multiple multiple value (output)
* \param calc_bc_dist nonzero if distances between bytecodes should be
* calculated, 0 if error should be returned in this case
* \return 1 on error (set with yasm_error_set), 0 on success.
*/
int yasm_bc_get_multiple(yasm_bytecode *bc, /*@out@*/ long *multiple,
int calc_bc_dist);
/** Create a new data value from an expression.
* \param expn expression
* \return Newly allocated data value.
*/
yasm_dataval *yasm_dv_create_expr(/*@keep@*/ yasm_expr *expn);
/** Create a new data value from a string.
* \param contents string (may contain NULs)
* \param len length of string
* \return Newly allocated data value.
*/
yasm_dataval *yasm_dv_create_string(/*@keep@*/ char *contents, size_t len);
/** Create a new data value from raw bytes data.
* \param contents raw data (may contain NULs)
* \param len length
* \return Newly allocated data value.
*/
yasm_dataval *yasm_dv_create_raw(/*@keep@*/ unsigned char *contents,
unsigned long len);
#ifndef YASM_DOXYGEN
#define yasm_dv_create_string(s, l) yasm_dv_create_raw((unsigned char *)(s), \
(unsigned long)(l))
#endif
/** Initialize a list of data values.
* \param headp list of data values
*/
void yasm_dvs_initialize(yasm_datavalhead *headp);
#ifdef YASM_LIB_INTERNAL
#define yasm_dvs_initialize(headp) STAILQ_INIT(headp)
#endif
/** Delete (free allocated memory for) a list of data values.
* \param headp list of data values
*/
void yasm_dvs_delete(yasm_datavalhead *headp);
/** Add data value to the end of a list of data values.
* \note Does not make a copy of the data value; so don't pass this function
* static or local variables, and discard the dv pointer after calling
* this function.
* \param headp data value list
* \param dv data value (may be NULL)
* \return If data value was actually appended (it wasn't NULL), the data
* value; otherwise NULL.
*/
/*@null@*/ yasm_dataval *yasm_dvs_append
(yasm_datavalhead *headp, /*@returned@*/ /*@null@*/ yasm_dataval *dv);
/** Print a data value list. For debugging purposes.
* \param f file
* \param indent_level indentation level
* \param headp data value list
*/
void yasm_dvs_print(const yasm_datavalhead *headp, FILE *f, int indent_level);
#endif