mpir/yasm/libyasm/expr.h
2011-12-04 12:01:57 +00:00

387 lines
15 KiB
C

/**
* \file libyasm/expr.h
* \brief YASM expression interface.
*
* \license
* Copyright (C) 2001-2007 Michael Urman, 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_EXPR_H
#define YASM_EXPR_H
#ifndef YASM_LIB_DECL
#define YASM_LIB_DECL
#endif
/** 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 enum yasm_expr__type {
YASM_EXPR_NONE = 0, /**< Nothing */
YASM_EXPR_REG = 1<<0, /**< Register */
YASM_EXPR_INT = 1<<1, /**< Integer value */
YASM_EXPR_SUBST = 1<<2, /**< Substitution placeholder */
YASM_EXPR_FLOAT = 1<<3, /**< Floating point value */
YASM_EXPR_SYM = 1<<4, /**< Symbol */
YASM_EXPR_PRECBC = 1<<5,/**< Direct bytecode ref (rather than via sym) */
YASM_EXPR_EXPR = 1<<6 /**< Subexpression */
} yasm_expr__type;
/** Expression item. */
typedef struct yasm_expr__item {
yasm_expr__type type; /**< Type */
/** Expression item data. Correct value depends on type. */
union {
yasm_bytecode *precbc; /**< Direct bytecode ref (YASM_EXPR_PRECBC) */
yasm_symrec *sym; /**< Symbol (YASM_EXPR_SYM) */
yasm_expr *expn; /**< Subexpression (YASM_EXPR_EXPR) */
yasm_intnum *intn; /**< Integer value (YASM_EXPR_INT) */
yasm_floatnum *flt; /**< Floating point value (YASM_EXPR_FLOAT) */
uintptr_t reg; /**< Register (YASM_EXPR_REG) */
unsigned int subst; /**< Subst placeholder (YASM_EXPR_SUBST) */
} data;
} yasm_expr__item;
/** Expression. */
struct yasm_expr {
yasm_expr_op op; /**< Operation. */
unsigned long line; /**< Line number where expression was defined. */
int numterms; /**< Number of terms in the expression. */
/** Terms of the expression. Structure may be extended to include more
* terms, as some operations may allow more than two operand terms
* (ADD, MUL, OR, AND, XOR).
*/
yasm_expr__item terms[2];
};
/** Create a new expression e=a op b.
* \param op operation
* \param a expression item a
* \param b expression item b (optional depending on op)
* \param line virtual line (where expression defined)
* \return Newly allocated expression.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr *yasm_expr_create
(yasm_expr_op op, /*@only@*/ yasm_expr__item *a,
/*@only@*/ /*@null@*/ yasm_expr__item *b, unsigned long line);
/** Create a new preceding-bytecode expression item.
* \param precbc preceding bytecode
* \return Newly allocated expression item.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr__item *yasm_expr_precbc(/*@keep@*/ yasm_bytecode *precbc);
/** Create a new symbol expression item.
* \param sym symbol
* \return Newly allocated expression item.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr__item *yasm_expr_sym(/*@keep@*/ yasm_symrec *sym);
/** Create a new expression expression item.
* \param e expression
* \return Newly allocated expression item.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr__item *yasm_expr_expr(/*@keep@*/ yasm_expr *e);
/** Create a new intnum expression item.
* \param intn intnum
* \return Newly allocated expression item.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr__item *yasm_expr_int(/*@keep@*/ yasm_intnum *intn);
/** Create a new floatnum expression item.
* \param flt floatnum
* \return Newly allocated expression item.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr__item *yasm_expr_float(/*@keep@*/ yasm_floatnum *flt);
/** Create a new register expression item.
* \param reg register
* \return Newly allocated expression item.
*/
YASM_LIB_DECL
/*@only@*/ yasm_expr__item *yasm_expr_reg(uintptr_t reg);
/** Create a new expression tree e=l op r.
* \param l expression for left side of new expression
* \param o operation
* \param r expression for right side of new expression
* \param i line index
* \return Newly allocated expression.
*/
#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 branch e=op r.
* \param o operation
* \param r expression for right side of new expression
* \param i line index
* \return Newly allocated expression.
*/
#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 identity e=r.
* \param r expression for identity within new expression
* \param i line index
* \return Newly allocated expression.
*/
#define yasm_expr_create_ident(r,i) \
yasm_expr_create (YASM_EXPR_IDENT, (r), (yasm_expr__item *)NULL, i)
/** Duplicate an expression.
* \param e expression
* \return Newly allocated expression identical to e.
*/
yasm_expr *yasm_expr_copy(const yasm_expr *e);
#ifndef YASM_DOXYGEN
#define yasm_expr_copy(e) yasm_expr__copy_except(e, -1)
#endif
/** Destroy (free allocated memory for) an expression.
* \param e expression
*/
YASM_LIB_DECL
void yasm_expr_destroy(/*@only@*/ /*@null@*/ yasm_expr *e);
/** Determine if an expression is a specified operation (at the top level).
* \param e expression
* \param op operator
* \return Nonzero if the expression was the specified operation at the top
* level, zero otherwise.
*/
YASM_LIB_DECL
int yasm_expr_is_op(const yasm_expr *e, yasm_expr_op op);
/** Extra transformation function for yasm_expr__level_tree().
* \param e expression being simplified
* \param d data provided as expr_xform_extra_data to
* yasm_expr__level_tree()
* \return Transformed e.
*/
typedef /*@only@*/ yasm_expr * (*yasm_expr_xform_func)
(/*@returned@*/ /*@only@*/ yasm_expr *e, /*@null@*/ void *d);
/** Level an entire expression tree.
* \internal
* \param e expression
* \param fold_const enable constant folding if nonzero
* \param simplify_ident simplify identities
* \param simplify_reg_mul simplify REG*1 identities
* \param calc_bc_dist nonzero if distances between bytecodes should be
* calculated, 0 if they should be left intact
* \param expr_xform_extra extra transformation function
* \param expr_xform_extra_data data to pass to expr_xform_extra
* \return Leveled expression.
*/
YASM_LIB_DECL
/*@only@*/ /*@null@*/ yasm_expr *yasm_expr__level_tree
(/*@returned@*/ /*@only@*/ /*@null@*/ yasm_expr *e, int fold_const,
int simplify_ident, int simplify_reg_mul, int calc_bc_dist,
/*@null@*/ yasm_expr_xform_func expr_xform_extra,
/*@null@*/ void *expr_xform_extra_data);
/** Simplify an expression as much as possible. Eliminates extraneous
* branches and simplifies integer-only subexpressions. Simplified version
* of yasm_expr__level_tree().
* \param e expression
* \param cbd if distance between bytecodes should be calculated
* \return Simplified expression.
*/
#define yasm_expr_simplify(e, cbd) \
yasm_expr__level_tree(e, 1, 1, 1, cbd, NULL, NULL)
/** Extract the segment portion of an expression containing SEG:OFF, leaving
* the offset.
* \param ep expression (pointer to)
* \return 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
/*@only@*/ /*@null@*/ yasm_expr *yasm_expr_extract_deep_segoff(yasm_expr **ep);
/** Extract the segment portion of a SEG:OFF expression, leaving the offset.
* \param ep expression (pointer to)
* \return 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
/*@only@*/ /*@null@*/ yasm_expr *yasm_expr_extract_segoff(yasm_expr **ep);
/** Extract the right portion (y) of a x WRT y expression, leaving the left
* portion (x).
* \param ep expression (pointer to)
* \return 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
/*@only@*/ /*@null@*/ yasm_expr *yasm_expr_extract_wrt(yasm_expr **ep);
/** Get the integer value of an expression if it's just an integer.
* \param ep expression (pointer to)
* \param calc_bc_dist nonzero if distances between bytecodes should be
* calculated, 0 if NULL should be returned in this case
* \return 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
/*@dependent@*/ /*@null@*/ yasm_intnum *yasm_expr_get_intnum
(yasm_expr **ep, int calc_bc_dist);
/** Get the symbol value of an expression if it's just a symbol.
* \param ep expression (pointer to)
* \param simplify if nonzero, simplify the expression first
* \return NULL if the expression is too complex; otherwise the symbol value of
* the expression.
*/
YASM_LIB_DECL
/*@dependent@*/ /*@null@*/ const yasm_symrec *yasm_expr_get_symrec
(yasm_expr **ep, int simplify);
/** Get the register value of an expression if it's just a register.
* \param ep expression (pointer to)
* \param simplify if nonzero, simplify the expression first
* \return NULL if the expression is too complex; otherwise the register value
* of the expression.
*/
YASM_LIB_DECL
/*@dependent@*/ /*@null@*/ const uintptr_t *yasm_expr_get_reg
(yasm_expr **ep, int simplify);
/** Print an expression. For debugging purposes.
* \param e expression
* \param f file
*/
YASM_LIB_DECL
void yasm_expr_print(/*@null@*/ const yasm_expr *e, FILE *f);
/** Return the size of an expression, if the user provided it
* \param e expression
*/
unsigned int yasm_expr_size(const yasm_expr *e);
/** Return the segment of an expression, if the user provided it
* \param e expression
*/
const char *yasm_expr_segment(const yasm_expr *e);
/** Traverse over expression tree in order (const version).
* Calls func for each leaf (non-operation).
* \param e expression
* \param d data passed to each call to func
* \param func callback function
* \return 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, /*@null@*/ void *d,
int (*func) (/*@null@*/ const yasm_expr__item *ei, /*@null@*/ void *d));
/** Traverse over expression tree in order.
* Calls func for each leaf (non-operation).
* \param e expression
* \param d data passed to each call to func
* \param func callback function
* \return Stops early (and returns 1) if func returns 1.
* Otherwise returns 0.
*/
YASM_LIB_DECL
int yasm_expr__traverse_leaves_in
(yasm_expr *e, /*@null@*/ void *d,
int (*func) (/*@null@*/ yasm_expr__item *ei, /*@null@*/ void *d));
/** 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.
* \param e expression
* \note Only performs reordering on *one* level (no recursion).
*/
YASM_LIB_DECL
void yasm_expr__order_terms(yasm_expr *e);
/** Copy entire expression EXCEPT for index "except" at *top level only*.
* \param e expression
* \param except term index not to copy; -1 to copy all terms
* \return Newly allocated copy of expression.
*/
YASM_LIB_DECL
yasm_expr *yasm_expr__copy_except(const yasm_expr *e, int except);
/** Test if expression contains an item. Searches recursively into
* subexpressions.
* \param e expression
* \param t type of item to look for
* \return Nonzero if expression contains an item of type t, zero if not.
*/
YASM_LIB_DECL
int yasm_expr__contains(const yasm_expr *e, yasm_expr__type t);
/** Transform symrec-symrec terms in expression into #YASM_EXPR_SUBST items.
* Calls the callback function for each symrec-symrec term.
* \param ep expression (pointer to)
* \param cbd callback data passed to callback function
* \param callback callback function: given subst index for bytecode
* pair, bytecode pair (bc2-bc1), and cbd (callback data)
* \return Number of transformations made.
*/
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));
/** Substitute items into expr YASM_EXPR_SUBST items (by index). Items are
* copied, so caller is responsible for freeing array of items.
* \param e expression
* \param num_items number of items in items array
* \param items items array
* \return 1 on error (index out of range).
*/
YASM_LIB_DECL
int yasm_expr__subst(yasm_expr *e, unsigned int num_items,
const yasm_expr__item *items);
#endif