| /* |
| * Align bytecode |
| * |
| * Copyright (C) 2005-2007 Peter Johnson |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| */ |
| #include "util.h" |
| |
| #include "libyasm-stdint.h" |
| #include "coretype.h" |
| |
| #include "errwarn.h" |
| #include "intnum.h" |
| #include "expr.h" |
| |
| #include "bytecode.h" |
| |
| |
| typedef struct bytecode_align { |
| /*@only@*/ yasm_expr *boundary; /* alignment boundary */ |
| |
| /* What to fill intervening locations with, NULL if using code_fill */ |
| /*@only@*/ /*@null@*/ yasm_expr *fill; |
| |
| /* Maximum number of bytes to skip, NULL if no maximum. */ |
| /*@only@*/ /*@null@*/ yasm_expr *maxskip; |
| |
| /* Code fill, NULL if using 0 fill */ |
| /*@null@*/ const unsigned char **code_fill; |
| } bytecode_align; |
| |
| static void bc_align_destroy(void *contents); |
| static void bc_align_print(const void *contents, FILE *f, int indent_level); |
| static void bc_align_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc); |
| static int bc_align_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, |
| void *add_span_data); |
| static int bc_align_expand(yasm_bytecode *bc, int span, long old_val, |
| long new_val, /*@out@*/ long *neg_thres, |
| /*@out@*/ long *pos_thres); |
| static int bc_align_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); |
| |
| static const yasm_bytecode_callback bc_align_callback = { |
| bc_align_destroy, |
| bc_align_print, |
| bc_align_finalize, |
| NULL, |
| bc_align_calc_len, |
| bc_align_expand, |
| bc_align_tobytes, |
| YASM_BC_SPECIAL_OFFSET |
| }; |
| |
| |
| static void |
| bc_align_destroy(void *contents) |
| { |
| bytecode_align *align = (bytecode_align *)contents; |
| if (align->boundary) |
| yasm_expr_destroy(align->boundary); |
| if (align->fill) |
| yasm_expr_destroy(align->fill); |
| if (align->maxskip) |
| yasm_expr_destroy(align->maxskip); |
| yasm_xfree(contents); |
| } |
| |
| static void |
| bc_align_print(const void *contents, FILE *f, int indent_level) |
| { |
| const bytecode_align *align = (const bytecode_align *)contents; |
| fprintf(f, "%*s_Align_\n", indent_level, ""); |
| fprintf(f, "%*sBoundary=", indent_level, ""); |
| yasm_expr_print(align->boundary, f); |
| fprintf(f, "\n%*sFill=", indent_level, ""); |
| yasm_expr_print(align->fill, f); |
| fprintf(f, "\n%*sMax Skip=", indent_level, ""); |
| yasm_expr_print(align->maxskip, f); |
| fprintf(f, "\n"); |
| } |
| |
| static void |
| bc_align_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc) |
| { |
| bytecode_align *align = (bytecode_align *)bc->contents; |
| if (!yasm_expr_get_intnum(&align->boundary, 0)) |
| yasm_error_set(YASM_ERROR_NOT_CONSTANT, |
| N_("align boundary must be a constant")); |
| if (align->fill && !yasm_expr_get_intnum(&align->fill, 0)) |
| yasm_error_set(YASM_ERROR_NOT_CONSTANT, |
| N_("align fill must be a constant")); |
| if (align->maxskip && !yasm_expr_get_intnum(&align->maxskip, 0)) |
| yasm_error_set(YASM_ERROR_NOT_CONSTANT, |
| N_("align maximum skip must be a constant")); |
| } |
| |
| static int |
| bc_align_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, |
| void *add_span_data) |
| { |
| long neg_thres = 0; |
| long pos_thres = 0; |
| |
| if (bc_align_expand(bc, 0, 0, (long)bc->offset, &neg_thres, |
| &pos_thres) < 0) |
| return -1; |
| |
| return 0; |
| } |
| |
| static int |
| bc_align_expand(yasm_bytecode *bc, int span, long old_val, long new_val, |
| /*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres) |
| { |
| bytecode_align *align = (bytecode_align *)bc->contents; |
| unsigned long end; |
| unsigned long boundary = |
| yasm_intnum_get_uint(yasm_expr_get_intnum(&align->boundary, 0)); |
| |
| if (boundary == 0) { |
| bc->len = 0; |
| *pos_thres = new_val; |
| return 0; |
| } |
| |
| end = (unsigned long)new_val; |
| if ((unsigned long)new_val & (boundary-1)) |
| end = ((unsigned long)new_val & ~(boundary-1)) + boundary; |
| |
| *pos_thres = (long)end; |
| bc->len = end - (unsigned long)new_val; |
| |
| if (align->maxskip) { |
| unsigned long maxskip = |
| yasm_intnum_get_uint(yasm_expr_get_intnum(&align->maxskip, 0)); |
| if (bc->len > maxskip) { |
| *pos_thres = (long)end-maxskip-1; |
| bc->len = 0; |
| } |
| } |
| return 1; |
| } |
| |
| static int |
| bc_align_tobytes(yasm_bytecode *bc, unsigned char **bufp, |
| unsigned char *bufstart, void *d, |
| yasm_output_value_func output_value, |
| /*@unused@*/ yasm_output_reloc_func output_reloc) |
| { |
| bytecode_align *align = (bytecode_align *)bc->contents; |
| unsigned long len; |
| unsigned long boundary = |
| yasm_intnum_get_uint(yasm_expr_get_intnum(&align->boundary, 0)); |
| |
| if (boundary == 0) |
| return 0; |
| else { |
| unsigned long end = bc->offset; |
| if (bc->offset & (boundary-1)) |
| end = (bc->offset & ~(boundary-1)) + boundary; |
| len = end - bc->offset; |
| if (len == 0) |
| return 0; |
| if (align->maxskip) { |
| unsigned long maxskip = |
| yasm_intnum_get_uint(yasm_expr_get_intnum(&align->maxskip, 0)); |
| if (len > maxskip) |
| return 0; |
| } |
| } |
| |
| if (align->fill) { |
| unsigned long v; |
| v = yasm_intnum_get_uint(yasm_expr_get_intnum(&align->fill, 0)); |
| memset(*bufp, (int)v, len); |
| *bufp += len; |
| } else if (align->code_fill) { |
| unsigned long maxlen = 15; |
| while (!align->code_fill[maxlen] && maxlen>0) |
| maxlen--; |
| if (maxlen == 0) { |
| yasm_error_set(YASM_ERROR_GENERAL, |
| N_("could not find any code alignment size")); |
| return 1; |
| } |
| |
| /* Fill with maximum code fill as much as possible */ |
| while (len > maxlen) { |
| memcpy(*bufp, align->code_fill[maxlen], maxlen); |
| *bufp += maxlen; |
| len -= maxlen; |
| } |
| |
| if (!align->code_fill[len]) { |
| yasm_error_set(YASM_ERROR_VALUE, |
| N_("invalid alignment size %d"), len); |
| return 1; |
| } |
| /* Handle rest of code fill */ |
| memcpy(*bufp, align->code_fill[len], len); |
| *bufp += len; |
| } else { |
| /* Just fill with 0 */ |
| memset(*bufp, 0, len); |
| *bufp += len; |
| } |
| return 0; |
| } |
| |
| yasm_bytecode * |
| yasm_bc_create_align(yasm_expr *boundary, yasm_expr *fill, |
| yasm_expr *maxskip, const unsigned char **code_fill, |
| unsigned long line) |
| { |
| bytecode_align *align = yasm_xmalloc(sizeof(bytecode_align)); |
| |
| align->boundary = boundary; |
| align->fill = fill; |
| align->maxskip = maxskip; |
| align->code_fill = code_fill; |
| |
| return yasm_bc_create_common(&bc_align_callback, align, line); |
| } |
