path: root/contrib/tools/yasm/modules/objfmts/coff/win64-except.c

/* 
 * Win64 structured exception handling support 
 * 
 *  Copyright (C) 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.h> 
 
#include "coff-objfmt.h" 
 
 
#define UNW_FLAG_EHANDLER   0x01 
#define UNW_FLAG_UHANDLER   0x02 
#define UNW_FLAG_CHAININFO  0x04 
 
/* Bytecode callback function prototypes */ 
static void win64_uwinfo_bc_destroy(void *contents); 
static void win64_uwinfo_bc_print(const void *contents, FILE *f, 
                                  int indent_level); 
static void win64_uwinfo_bc_finalize(yasm_bytecode *bc, 
                                     yasm_bytecode *prev_bc); 
static int win64_uwinfo_bc_calc_len 
    (yasm_bytecode *bc, yasm_bc_add_span_func add_span, void *add_span_data); 
static int win64_uwinfo_bc_expand(yasm_bytecode *bc, int span, long old_val, 
                                  long new_val, /*@out@*/ long *neg_thres, 
                                  /*@out@*/ long *pos_thres); 
static int win64_uwinfo_bc_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 void win64_uwcode_bc_destroy(void *contents); 
static void win64_uwcode_bc_print(const void *contents, FILE *f, 
                                  int indent_level); 
static void win64_uwcode_bc_finalize(yasm_bytecode *bc, 
                                     yasm_bytecode *prev_bc); 
static int win64_uwcode_bc_calc_len 
    (yasm_bytecode *bc, yasm_bc_add_span_func add_span, void *add_span_data); 
static int win64_uwcode_bc_expand(yasm_bytecode *bc, int span, long old_val, 
                                  long new_val, /*@out@*/ long *neg_thres, 
                                  /*@out@*/ long *pos_thres); 
static int win64_uwcode_bc_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); 
 
/* Bytecode callback structures */ 
static const yasm_bytecode_callback win64_uwinfo_bc_callback = { 
    win64_uwinfo_bc_destroy, 
    win64_uwinfo_bc_print, 
    win64_uwinfo_bc_finalize, 
    NULL, 
    win64_uwinfo_bc_calc_len, 
    win64_uwinfo_bc_expand, 
    win64_uwinfo_bc_tobytes, 
    0 
}; 
 
static const yasm_bytecode_callback win64_uwcode_bc_callback = { 
    win64_uwcode_bc_destroy, 
    win64_uwcode_bc_print, 
    win64_uwcode_bc_finalize, 
    NULL, 
    win64_uwcode_bc_calc_len, 
    win64_uwcode_bc_expand, 
    win64_uwcode_bc_tobytes, 
    0 
}; 
 
 
coff_unwind_info * 
yasm_win64__uwinfo_create(void) 
{ 
    coff_unwind_info *info = yasm_xmalloc(sizeof(coff_unwind_info)); 
    info->proc = NULL; 
    info->prolog = NULL; 
    info->ehandler = NULL; 
    info->framereg = 0; 
    /* Frameoff is really a 4-bit value, scaled by 16 */ 
    yasm_value_initialize(&info->frameoff, NULL, 8); 
    SLIST_INIT(&info->codes); 
    yasm_value_initialize(&info->prolog_size, NULL, 8); 
    yasm_value_initialize(&info->codes_count, NULL, 8); 
    return info; 
} 
 
void 
yasm_win64__uwinfo_destroy(coff_unwind_info *info) 
{ 
    coff_unwind_code *code; 
 
    yasm_value_delete(&info->frameoff); 
    yasm_value_delete(&info->prolog_size); 
    yasm_value_delete(&info->codes_count); 
 
    while (!SLIST_EMPTY(&info->codes)) { 
        code = SLIST_FIRST(&info->codes); 
        SLIST_REMOVE_HEAD(&info->codes, link); 
        yasm_value_delete(&code->off); 
        yasm_xfree(code); 
    } 
    yasm_xfree(info); 
} 
 
void 
yasm_win64__unwind_generate(yasm_section *xdata, coff_unwind_info *info, 
                            unsigned long line) 
{ 
    yasm_bytecode *infobc, *codebc = NULL; 
    coff_unwind_code *code; 
 
    /* 4-byte align the start of unwind info */ 
    yasm_section_bcs_append(xdata, yasm_bc_create_align( 
        yasm_expr_create_ident(yasm_expr_int(yasm_intnum_create_uint(4)), 
                               line), 
        NULL, NULL, NULL, line)); 
 
    /* Prolog size = end of prolog - start of procedure */ 
    yasm_value_initialize(&info->prolog_size, 
        yasm_expr_create(YASM_EXPR_SUB, yasm_expr_sym(info->prolog), 
                         yasm_expr_sym(info->proc), line), 
        8); 
 
    /* Unwind info */ 
    infobc = yasm_bc_create_common(&win64_uwinfo_bc_callback, info, line); 
    yasm_section_bcs_append(xdata, infobc); 
 
    /* Code array */ 
    SLIST_FOREACH(code, &info->codes, link) { 
        codebc = yasm_bc_create_common(&win64_uwcode_bc_callback, code, 
                                       yasm_symrec_get_def_line(code->loc)); 
        yasm_section_bcs_append(xdata, codebc); 
    } 
 
    /* Avoid double-free (by code destroy and uwinfo destroy). */ 
    SLIST_INIT(&info->codes); 
 
    /* Number of codes = (Last code - end of info) >> 1 */ 
    if (!codebc) { 
        yasm_value_initialize(&info->codes_count, 
            yasm_expr_create_ident(yasm_expr_int(yasm_intnum_create_uint(0)), 
                                   line), 
            8); 
    } else { 
        yasm_value_initialize(&info->codes_count, 
            yasm_expr_create(YASM_EXPR_SHR, yasm_expr_expr( 
                yasm_expr_create(YASM_EXPR_SUB, yasm_expr_precbc(codebc), 
                                 yasm_expr_precbc(infobc), line)), 
                yasm_expr_int(yasm_intnum_create_uint(1)), line), 
            8); 
    } 
 
    /* 4-byte align */ 
    yasm_section_bcs_append(xdata, yasm_bc_create_align( 
        yasm_expr_create_ident(yasm_expr_int(yasm_intnum_create_uint(4)), 
                               line), 
        NULL, NULL, NULL, line)); 
 
    /* Exception handler, if present.  Use data bytecode. */ 
    if (info->ehandler) { 
        yasm_datavalhead dvs; 
 
        yasm_dvs_initialize(&dvs); 
        yasm_dvs_append(&dvs, yasm_dv_create_expr( 
            yasm_expr_create_ident(yasm_expr_sym(info->ehandler), line))); 
        yasm_section_bcs_append(xdata, 
                                yasm_bc_create_data(&dvs, 4, 0, NULL, line)); 
    } 
} 
 
static void 
win64_uwinfo_bc_destroy(void *contents) 
{ 
    yasm_win64__uwinfo_destroy((coff_unwind_info *)contents); 
} 
 
static void 
win64_uwinfo_bc_print(const void *contents, FILE *f, int indent_level) 
{ 
    /* TODO */ 
} 
 
static void 
win64_uwinfo_bc_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc) 
{ 
    coff_unwind_info *info = (coff_unwind_info *)bc->contents; 
 
    if (yasm_value_finalize(&info->prolog_size, prev_bc)) 
        yasm_internal_error(N_("prolog size expression too complex")); 
 
    if (yasm_value_finalize(&info->codes_count, prev_bc)) 
        yasm_internal_error(N_("codes count expression too complex")); 
 
    if (yasm_value_finalize(&info->frameoff, prev_bc)) 
        yasm_error_set(YASM_ERROR_VALUE, 
                       N_("frame offset expression too complex")); 
} 
 
static int 
win64_uwinfo_bc_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, 
                         void *add_span_data) 
{ 
    coff_unwind_info *info = (coff_unwind_info *)bc->contents; 
    /*@only@*/ /*@null@*/ yasm_intnum *intn; 
    long intv; 
 
    /* Want to make sure prolog size and codes count doesn't exceed 
     * byte-size, and scaled frame offset doesn't exceed 4 bits. 
     */ 
    add_span(add_span_data, bc, 1, &info->prolog_size, 0, 255); 
    add_span(add_span_data, bc, 2, &info->codes_count, 0, 255); 
 
    intn = yasm_value_get_intnum(&info->frameoff, bc, 0); 
    if (intn) { 
        intv = yasm_intnum_get_int(intn); 
        if (intv < 0 || intv > 240) 
            yasm_error_set(YASM_ERROR_VALUE, 
                N_("frame offset of %ld bytes, must be between 0 and 240"), 
                intv); 
        else if ((intv & 0xF) != 0) 
            yasm_error_set(YASM_ERROR_VALUE, 
                N_("frame offset of %ld is not a multiple of 16"), intv); 
        yasm_intnum_destroy(intn); 
    } else 
        add_span(add_span_data, bc, 3, &info->frameoff, 0, 240); 
 
    bc->len += 4; 
    return 0; 
} 
 
static int 
win64_uwinfo_bc_expand(yasm_bytecode *bc, int span, long old_val, long new_val, 
                       /*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres) 
{ 
    coff_unwind_info *info = (coff_unwind_info *)bc->contents; 
    switch (span) { 
        case 1: 
            yasm_error_set_xref(yasm_symrec_get_def_line(info->prolog), 
                                N_("prologue ended here")); 
            yasm_error_set(YASM_ERROR_VALUE, 
                           N_("prologue %ld bytes, must be <256"), new_val); 
            return -1; 
        case 2: 
            yasm_error_set(YASM_ERROR_VALUE, 
                           N_("%ld unwind codes, maximum of 255"), new_val); 
            return -1; 
        case 3: 
            yasm_error_set(YASM_ERROR_VALUE, 
                N_("frame offset of %ld bytes, must be between 0 and 240"), 
                new_val); 
            return -1; 
        default: 
            yasm_internal_error(N_("unrecognized span id")); 
    } 
    return 0; 
} 
 
static int 
win64_uwinfo_bc_tobytes(yasm_bytecode *bc, unsigned char **bufp, 
                        unsigned char *bufstart, void *d, 
                        yasm_output_value_func output_value, 
                        yasm_output_reloc_func output_reloc) 
{ 
    coff_unwind_info *info = (coff_unwind_info *)bc->contents; 
    unsigned char *buf = *bufp; 
    /*@only@*/ /*@null@*/ yasm_intnum *frameoff; 
    long intv; 
 
    /* Version and flags */ 
    if (info->ehandler) 
        YASM_WRITE_8(buf, 1 | (UNW_FLAG_EHANDLER << 3)); 
    else 
        YASM_WRITE_8(buf, 1); 
 
    /* Size of prolog */ 
    output_value(&info->prolog_size, buf, 1, (unsigned long)(buf-bufstart), 
                 bc, 1, d); 
    buf += 1; 
 
    /* Count of codes */ 
    output_value(&info->codes_count, buf, 1, (unsigned long)(buf-bufstart), 
                 bc, 1, d); 
    buf += 1; 
 
    /* Frame register and offset */ 
    frameoff = yasm_value_get_intnum(&info->frameoff, bc, 1); 
    if (!frameoff) { 
        yasm_error_set(YASM_ERROR_VALUE, 
                       N_("frame offset expression too complex")); 
        return 1; 
    } 
    intv = yasm_intnum_get_int(frameoff); 
    if (intv < 0 || intv > 240) 
        yasm_error_set(YASM_ERROR_VALUE, 
            N_("frame offset of %ld bytes, must be between 0 and 240"), intv); 
    else if ((intv & 0xF) != 0) 
        yasm_error_set(YASM_ERROR_VALUE, 
            N_("frame offset of %ld is not a multiple of 16"), intv); 
 
    YASM_WRITE_8(buf, ((unsigned long)intv & 0xF0) | (info->framereg & 0x0F)); 
    yasm_intnum_destroy(frameoff); 
 
    *bufp = buf; 
    return 0; 
} 
 
static void 
win64_uwcode_bc_destroy(void *contents) 
{ 
    coff_unwind_code *code = (coff_unwind_code *)contents; 
    yasm_value_delete(&code->off); 
    yasm_xfree(contents); 
} 
 
static void 
win64_uwcode_bc_print(const void *contents, FILE *f, int indent_level) 
{ 
    /* TODO */ 
} 
 
static void 
win64_uwcode_bc_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc) 
{ 
    coff_unwind_code *code = (coff_unwind_code *)bc->contents; 
    if (yasm_value_finalize(&code->off, prev_bc)) 
        yasm_error_set(YASM_ERROR_VALUE, N_("offset expression too complex")); 
} 
 
static int 
win64_uwcode_bc_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, 
                         void *add_span_data) 
{ 
    coff_unwind_code *code = (coff_unwind_code *)bc->contents; 
    int span = 0; 
    /*@only@*/ /*@null@*/ yasm_intnum *intn; 
    long intv; 
    long low, high, mask; 
 
    bc->len += 2;   /* Prolog offset, code, and info */ 
 
    switch (code->opcode) { 
        case UWOP_PUSH_NONVOL: 
        case UWOP_SET_FPREG: 
        case UWOP_PUSH_MACHFRAME: 
            /* always 1 node */ 
            return 0; 
        case UWOP_ALLOC_SMALL: 
        case UWOP_ALLOC_LARGE: 
            /* Start with smallest, then work our way up as necessary */ 
            code->opcode = UWOP_ALLOC_SMALL; 
            code->info = 0; 
            span = 1; low = 8; high = 128; mask = 0x7; 
            break; 
        case UWOP_SAVE_NONVOL: 
        case UWOP_SAVE_NONVOL_FAR: 
            /* Start with smallest, then work our way up as necessary */ 
            code->opcode = UWOP_SAVE_NONVOL; 
            bc->len += 2;   /* Scaled offset */ 
            span = 2; 
            low = 0; 
            high = 8*64*1024-8;         /* 16-bit field, *8 scaling */ 
            mask = 0x7; 
            break; 
        case UWOP_SAVE_XMM128: 
        case UWOP_SAVE_XMM128_FAR: 
            /* Start with smallest, then work our way up as necessary */ 
            code->opcode = UWOP_SAVE_XMM128; 
            bc->len += 2;   /* Scaled offset */ 
            span = 3; 
            low = 0; 
            high = 16*64*1024-16;       /* 16-bit field, *16 scaling */ 
            mask = 0xF; 
            break; 
        default: 
            yasm_internal_error(N_("unrecognied unwind opcode")); 
            /*@unreached@*/ 
            return 0; 
    } 
 
    intn = yasm_value_get_intnum(&code->off, bc, 0); 
    if (intn) { 
        intv = yasm_intnum_get_int(intn); 
        if (intv > high) { 
            /* Expand it ourselves here if we can and we're already larger */ 
            if (win64_uwcode_bc_expand(bc, span, intv, intv, &low, &high) > 0) 
                add_span(add_span_data, bc, span, &code->off, low, high); 
        } 
        if (intv < low) 
            yasm_error_set(YASM_ERROR_VALUE, 
                           N_("negative offset not allowed")); 
        if ((intv & mask) != 0) 
            yasm_error_set(YASM_ERROR_VALUE, 
                N_("offset of %ld is not a multiple of %ld"), intv, mask+1); 
        yasm_intnum_destroy(intn); 
    } else 
        add_span(add_span_data, bc, span, &code->off, low, high); 
    return 0; 
} 
 
static int 
win64_uwcode_bc_expand(yasm_bytecode *bc, int span, long old_val, long new_val, 
                       /*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres) 
{ 
    coff_unwind_code *code = (coff_unwind_code *)bc->contents; 
 
    if (new_val < 0) { 
        yasm_error_set(YASM_ERROR_VALUE, N_("negative offset not allowed")); 
        return -1; 
    } 
 
    if (span == 1) { 
        /* 3 stages: SMALL, LARGE and info=0, LARGE and info=1 */ 
        if (code->opcode == UWOP_ALLOC_LARGE && code->info == 1) 
            yasm_internal_error(N_("expansion on already largest alloc")); 
 
        if (code->opcode == UWOP_ALLOC_SMALL && new_val > 128) { 
            /* Overflowed small size */ 
            code->opcode = UWOP_ALLOC_LARGE; 
            bc->len += 2; 
        } 
        if (new_val <= 8*64*1024-8) { 
            /* Still can grow one more size */ 
            *pos_thres = 8*64*1024-8; 
            return 1; 
        } 
        /* We're into the largest size */ 
        code->info = 1; 
        bc->len += 2; 
    } else if (code->opcode == UWOP_SAVE_NONVOL && span == 2) { 
        code->opcode = UWOP_SAVE_NONVOL_FAR; 
        bc->len += 2; 
    } else if (code->opcode == UWOP_SAVE_XMM128 && span == 3) { 
        code->opcode = UWOP_SAVE_XMM128_FAR; 
        bc->len += 2; 
    } 
    return 0; 
} 
 
static int 
win64_uwcode_bc_tobytes(yasm_bytecode *bc, unsigned char **bufp, 
                        unsigned char *bufstart, void *d, 
                        yasm_output_value_func output_value, 
                        yasm_output_reloc_func output_reloc) 
{ 
    coff_unwind_code *code = (coff_unwind_code *)bc->contents; 
    unsigned char *buf = *bufp; 
    yasm_value val; 
    unsigned int size; 
    int shift; 
    long intv, low, high, mask; 
    yasm_intnum *intn; 
 
    /* Offset in prolog */ 
    yasm_value_initialize(&val, 
        yasm_expr_create(YASM_EXPR_SUB, yasm_expr_sym(code->loc), 
                         yasm_expr_sym(code->proc), bc->line), 
        8); 
    output_value(&val, buf, 1, (unsigned long)(buf-bufstart), bc, 1, d); 
    buf += 1; 
    yasm_value_delete(&val); 
 
    /* Offset value */ 
    switch (code->opcode) { 
        case UWOP_PUSH_NONVOL: 
        case UWOP_SET_FPREG: 
        case UWOP_PUSH_MACHFRAME: 
            /* just 1 node, no offset; write opcode and info and we're done */ 
            YASM_WRITE_8(buf, (code->info << 4) | (code->opcode & 0xF)); 
            *bufp = buf; 
            return 0; 
        case UWOP_ALLOC_SMALL: 
            /* 1 node, but offset stored in info */ 
            size = 0; low = 8; high = 128; shift = 3; mask = 0x7; 
            break; 
        case UWOP_ALLOC_LARGE: 
            if (code->info == 0) { 
                size = 2; low = 136; high = 8*64*1024-8; shift = 3; 
            } else { 
                size = 4; low = high = 0; shift = 0; 
            } 
            mask = 0x7; 
            break; 
        case UWOP_SAVE_NONVOL: 
            size = 2; low = 0; high = 8*64*1024-8; shift = 3; mask = 0x7; 
            break; 
        case UWOP_SAVE_XMM128: 
            size = 2; low = 0; high = 16*64*1024-16; shift = 4; mask = 0xF; 
            break; 
        case UWOP_SAVE_NONVOL_FAR: 
            size = 4; low = high = 0; shift = 0; mask = 0x7; 
            break; 
        case UWOP_SAVE_XMM128_FAR: 
            size = 4; low = high = 0; shift = 0; mask = 0xF; 
            break; 
        default: 
            yasm_internal_error(N_("unrecognied unwind opcode")); 
            /*@unreached@*/ 
            return 1; 
    } 
 
    /* Check for overflow */ 
    intn = yasm_value_get_intnum(&code->off, bc, 1); 
    if (!intn) { 
        yasm_error_set(YASM_ERROR_VALUE, N_("offset expression too complex")); 
        return 1; 
    } 
    intv = yasm_intnum_get_int(intn); 
    if (size != 4 && (intv < low || intv > high)) { 
        yasm_error_set(YASM_ERROR_VALUE, 
            N_("offset of %ld bytes, must be between %ld and %ld"), 
            intv, low, high); 
        return 1; 
    } 
    if ((intv & mask) != 0) { 
        yasm_error_set(YASM_ERROR_VALUE, 
                       N_("offset of %ld is not a multiple of %ld"), 
                       intv, mask+1); 
        return 1; 
    } 
 
    /* Stored value in info instead of extra code space */ 
    if (size == 0) 
        code->info = (yasm_intnum_get_uint(intn) >> shift)-1; 
 
    /* Opcode and info */ 
    YASM_WRITE_8(buf, (code->info << 4) | (code->opcode & 0xF)); 
 
    if (size != 0) { 
        yasm_intnum_get_sized(intn, buf, size, size*8, -shift, 0, 1); 
        buf += size; 
    } 
 
    yasm_intnum_destroy(intn); 
 
    *bufp = buf; 
    return 0; 
}