intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 638 insertions, 0 deletions

diff --git a/contrib/tools/yasm/libyasm/bytecode.h b/contrib/tools/yasm/libyasm/bytecode.h
new file mode 100644
index 00000000000..47cd26244b0
--- /dev/null
+++ b/contrib/tools/yasm/libyasm/bytecode.h
@@ -0,0 +1,638 @@
+/**
+ * \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_LIB_DECL
+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_LIB_DECL
+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_LIB_DECL
+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)
+ */
+YASM_LIB_DECL
+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.
+ */
+YASM_LIB_DECL
+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