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/**
* \file libyasm/bytecode.h
* \brief YASM bytecode interface.
*
* \license
* Copyright (C) 2001-2007 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
#ifndef YASM_LIB_DECL
#define YASM_LIB_DECL
#endif
/** A data value (opaque type). */
typedef struct yasm_dataval yasm_dataval;
/** A list of data values. */
typedef struct yasm_datavalhead yasm_datavalhead;
/** Linked list of data values. */
/*@reldef@*/ STAILQ_HEAD(yasm_datavalhead, yasm_dataval);
/** 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);
/** Bytecode callback structure. Any implementation of a specific bytecode
* must implement these functions and this callback structure. The bytecode
* implementation-specific data is stored in #yasm_bytecode.contents.
*/
typedef struct yasm_bytecode_callback {
/** Destroys the implementation-specific data.
* Called from yasm_bc_destroy().
* \param contents #yasm_bytecode.contents
*/
void (*destroy) (/*@only@*/ void *contents);
/** Prints the implementation-specific data (for debugging purposes).
* Called from yasm_bc_print().
* \param contents #yasm_bytecode.contents
* \param f file
* \param indent_level indentation level
*/
void (*print) (const void *contents, FILE *f, int indent_level);
/** Finalizes the bytecode after parsing. Called from yasm_bc_finalize().
* A generic fill-in for this is yasm_bc_finalize_common().
* \param bc bytecode
* \param prev_bc bytecode directly preceding bc
*/
void (*finalize) (yasm_bytecode *bc, yasm_bytecode *prev_bc);
/** Return elements size of a data bytecode.
* This function should return the size of each elements of a data
* bytecode, for proper dereference of symbols attached to it.
* \param bc bytecode
* \return 0 if element size is unknown.
*/
int (*elem_size) (yasm_bytecode *bc);
/** Calculates the minimum size of a bytecode.
* Called from yasm_bc_calc_len().
* A generic fill-in for this is yasm_bc_calc_len_common(), but as this
* function internal errors when called, be very careful when using it!
* This function should simply add to bc->len and not set it directly
* (it's initialized by yasm_bc_calc_len() prior to passing control to
* this function).
*
* \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.
*/
int (*calc_len) (yasm_bytecode *bc, yasm_bc_add_span_func add_span,
void *add_span_data);
/** Recalculates the bytecode's length based on an expanded span length.
* Called from yasm_bc_expand().
* A generic fill-in for this is yasm_bc_expand_common(), but as this
* function internal errors when called, if used, ensure that calc_len()
* never adds a span.
* This function should simply add to bc->len to increase the length by
* a delta amount.
* \param bc bytecode
* \param span span ID (as given to add_span in 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 positive 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.
*/
int (*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.
* Called from yasm_bc_tobytes().
* A generic fill-in for this is yasm_bc_tobytes_common(), but as this
* function internal errors when called, be very careful when using it!
* \param bc bytecode
* \param bufp byte representation destination buffer;
* should be incremented as it's written to,
* so that on return its delta from the
* passed-in buf matches the bytecode length
* (it's okay not to do this if an error
* indication is returned)
* \param bufstart For calculating the correct offset parameter for
* the \a output_value calls: *bufp - bufstart.
* \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 Nonzero on error, 0 on success.
* \note May result in non-reversible changes to the bytecode, but it's
* preferable if calling this function twice would result in the
* same output.
*/
int (*tobytes) (yasm_bytecode *bc, unsigned char **bufp,
unsigned char *bufstart, void *d,
yasm_output_value_func output_value,
/*@null@*/ yasm_output_reloc_func output_reloc);
/** Special bytecode classifications. Most bytecode types should use
* #YASM_BC_SPECIAL_NONE. Others cause special handling to kick in
* in various parts of yasm.
*/
enum yasm_bytecode_special_type {
YASM_BC_SPECIAL_NONE = 0,
/** Bytecode reserves space instead of outputting data. */
YASM_BC_SPECIAL_RESERVE,
/** Adjusts offset instead of calculating len. */
YASM_BC_SPECIAL_OFFSET,
/** Instruction bytecode. */
YASM_BC_SPECIAL_INSN
} special;
} yasm_bytecode_callback;
/** A bytecode. */
struct yasm_bytecode {
/** Bytecodes are stored as a singly linked list, with tail insertion.
* \see section.h (#yasm_section).
*/
/*@reldef@*/ STAILQ_ENTRY(yasm_bytecode) link;
/** The bytecode callback structure for this bytecode. May be NULL
* during partial initialization.
*/
/*@null@*/ const yasm_bytecode_callback *callback;
/** Pointer to section containing bytecode; NULL if not part of a
* section.
*/
/*@dependent@*/ /*@null@*/ yasm_section *section;
/** Number of times bytecode is repeated.
* NULL=1 (to save space in the common case).
*/
/*@only@*/ /*@null@*/ yasm_expr *multiple;
/** Total length of entire bytecode (not including multiple copies). */
unsigned long len;
/** Number of copies, integer version. */
long mult_int;
/** Line number where bytecode was defined. */
unsigned long line;
/** Offset of bytecode from beginning of its section.
* 0-based, ~0UL (e.g. all 1 bits) if unknown.
*/
unsigned long offset;
/** Unique integer index of bytecode. Used during optimization. */
unsigned long bc_index;
/** NULL-terminated array of labels that point to this bytecode (as the
* bytecode previous to the label). NULL if no labels point here.
*/
/*@null@*/ yasm_symrec **symrecs;
/** Implementation-specific data (type identified by callback). */
void *contents;
};
/** Create a bytecode of any specified type.
* \param callback bytecode callback functions, if NULL, creates empty
* bytecode (may not be resolved or output)
* \param contents type-specific data
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode of the specified type.
*/
YASM_LIB_DECL
/*@only@*/ yasm_bytecode *yasm_bc_create_common
(/*@null@*/ const yasm_bytecode_callback *callback,
/*@only@*/ /*@null@*/ void *contents, unsigned long line);
/** Transform a bytecode of any type into a different type.
* \param bc bytecode to transform
* \param callback new bytecode callback function
* \param contents new type-specific data
*/
YASM_LIB_DECL
void yasm_bc_transform(yasm_bytecode *bc,
const yasm_bytecode_callback *callback,
void *contents);
/** Common bytecode callback finalize function, for where no finalization
* is ever required for this type of bytecode.
*/
YASM_LIB_DECL
void yasm_bc_finalize_common(yasm_bytecode *bc, yasm_bytecode *prev_bc);
/** Common bytecode callback calc_len function, for where the bytecode has
* no calculatable length. Causes an internal error if called.
*/
YASM_LIB_DECL
int yasm_bc_calc_len_common(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
void *add_span_data);
/** Common bytecode callback expand function, for where the bytecode is
* always short (calc_len never calls add_span). Causes an internal
* error if called.
*/
YASM_LIB_DECL
int yasm_bc_expand_common
(yasm_bytecode *bc, int span, long old_val, long new_val,
/*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres);
/** Common bytecode callback tobytes function, for where the bytecode
* cannot be converted to bytes. Causes an internal error if called.
*/
YASM_LIB_DECL
int yasm_bc_tobytes_common
(yasm_bytecode *bc, unsigned char **bufp, unsigned char *bufstart, void *d,
yasm_output_value_func output_value,
/*@null@*/ yasm_output_reloc_func output_reloc);
/** Get the next bytecode in a linked list of bytecodes.
* \param bc bytecode
* \return Next bytecode.
*/
#define yasm_bc__next(bc) STAILQ_NEXT(bc, link)
/** 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)
*/
YASM_LIB_DECL
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.
*/
YASM_LIB_DECL
/*@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.
*/
YASM_LIB_DECL
/*@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.
*/
YASM_LIB_DECL
/*@only@*/ yasm_bytecode *yasm_bc_create_reserve
(/*@only@*/ yasm_expr *numitems, unsigned int itemsize,
unsigned long line);
/** Get the number of items and itemsize for a reserve bytecode. If bc
* is not a reserve bytecode, returns NULL.
* \param bc bytecode
* \param itemsize reserved size (in bytes) for each item (returned)
* \return NULL if bc is not a reserve bytecode, otherwise an expression
* for the number of items to reserve.
*/
YASM_LIB_DECL
/*@null@*/ const yasm_expr *yasm_bc_reserve_numitems
(yasm_bytecode *bc, /*@out@*/ unsigned int *itemsize);
/** 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.
*/
YASM_LIB_DECL
/*@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
*/
YASM_LIB_DECL
/*@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 fill fill value
* \param line virtual line (from yasm_linemap)
* \return Newly allocated bytecode.
*/
YASM_LIB_DECL
/*@only@*/ yasm_bytecode *yasm_bc_create_org
(unsigned long start, unsigned long fill, unsigned long line);
/** 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).
*/
YASM_LIB_DECL
/*@dependent@*/ /*@null@*/ yasm_section *yasm_bc_get_section
(yasm_bytecode *bc);
/** Add to the list of symrecs that reference a bytecode. For symrec use
* only.
* \param bc bytecode
* \param sym symbol
*/
YASM_LIB_DECL
void yasm_bc__add_symrec(yasm_bytecode *bc, /*@dependent@*/ yasm_symrec *sym);
/** Delete (free allocated memory for) a bytecode.
* \param bc bytecode (only pointer to it); may be NULL
*/
YASM_LIB_DECL
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
*/
YASM_LIB_DECL
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
*/
YASM_LIB_DECL
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.
*/
YASM_LIB_DECL
/*@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.
*/
YASM_LIB_DECL
unsigned long yasm_bc_next_offset(yasm_bytecode *precbc);
/** Return elemens size of a data bytecode.
* Returns the size of each elements of a data bytecode, for proper dereference
* of symbols attached to it.
* \param bc bytecode
* \return 0 if element size is unknown
*/
YASM_LIB_DECL
int yasm_bc_elem_size(yasm_bytecode *bc);
/** 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.
*/
YASM_LIB_DECL
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 positive 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.
*/
YASM_LIB_DECL
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.
*/
YASM_LIB_DECL
/*@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.
*/
YASM_LIB_DECL
int yasm_bc_get_multiple(yasm_bytecode *bc, /*@out@*/ long *multiple,
int calc_bc_dist);
/** Get the bytecode multiple value as an expression.
* \param bc bytecode
* \return Bytecode multiple, NULL if =1.
*/
YASM_LIB_DECL
const yasm_expr *yasm_bc_get_multiple_expr(const yasm_bytecode *bc);
/** Get a #yasm_insn structure from an instruction bytecode (if possible).
* \param bc bytecode
* \return Instruction details if bytecode is an instruction bytecode,
* otherwise NULL.
*/
YASM_LIB_DECL
/*@dependent@*/ /*@null@*/ yasm_insn *yasm_bc_get_insn(yasm_bytecode *bc);
/** Create a new data value from an expression.
* \param expn expression
* \return Newly allocated data value.
*/
YASM_LIB_DECL
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_LIB_DECL
yasm_dataval *yasm_dv_create_raw(/*@keep@*/ unsigned char *contents,
unsigned long len);
/** Create a new uninitialized data value.
* \return Newly allocated data value.
*/
yasm_dataval *yasm_dv_create_reserve(void);
#ifndef YASM_DOXYGEN
#define yasm_dv_create_string(s, l) yasm_dv_create_raw((unsigned char *)(s), \
(unsigned long)(l))
#endif
/** Get the underlying value of a data value.
* \param dv data value
* \return Value, or null if non-value (e.g. string or raw).
*/
yasm_value *yasm_dv_get_value(yasm_dataval *dv);
/** Set multiple field of a data value.
* A data value can be repeated a number of times when output. This function
* sets that multiple.
* \param dv data value
* \param e multiple (kept, do not free)
*/
void yasm_dv_set_multiple(yasm_dataval *dv, /*@keep@*/ yasm_expr *e);
/** Get the data value multiple value as an unsigned long integer.
* \param dv data value
* \param multiple multiple value (output)
* \return 1 on error (set with yasm_error_set), 0 on success.
*/
int yasm_dv_get_multiple(yasm_dataval *dv, /*@out@*/ unsigned long *multiple);
/** Initialize a list of data values.
* \param headp list of data values
*/
void yasm_dvs_initialize(yasm_datavalhead *headp);
#ifndef YASM_DOXYGEN
#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
*/
YASM_LIB_DECL
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.
*/
YASM_LIB_DECL
/*@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
*/
YASM_LIB_DECL
void yasm_dvs_print(const yasm_datavalhead *headp, FILE *f, int indent_level);
#endif
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