xdf-objfmt.c

支持AMD64的汇编编译器源码

/*
 * Extended Dynamic Object format
 *
 *  Copyright (C) 2004  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>
/*@unused@*/ RCSID("$Id: xdf-objfmt.c 1168 2004-10-31 01:07:52Z peter $");

#define YASM_LIB_INTERNAL
#define YASM_BC_INTERNAL
#define YASM_EXPR_INTERNAL
#include <libyasm.h>


#define REGULAR_OUTBUF_SIZE	1024

#define XDF_MAGIC	0x87654321

#define XDF_SYM_EXTERN	1
#define XDF_SYM_GLOBAL	2
#define XDF_SYM_EQU	4

typedef STAILQ_HEAD(xdf_reloc_head, xdf_reloc) xdf_reloc_head;

typedef struct xdf_reloc {
    yasm_reloc reloc;
    /*@null@*/ yasm_symrec *base;   /* base symbol (for WRT) */
    enum {
	XDF_RELOC_REL = 1,	    /* relative to segment */
	XDF_RELOC_WRT = 2,	    /* relative to symbol */
	XDF_RELOC_RIP = 4,	    /* RIP-relative */
	XDF_RELOC_SEG = 8	    /* segment containing symbol */
    } type;			    /* type of relocation */
    enum {
	XDF_RELOC_8  = 1,         
	XDF_RELOC_16 = 2,      
	XDF_RELOC_32 = 4,      
	XDF_RELOC_64 = 8
    } size;			    /* size of relocation */
    unsigned int shift;		    /* relocation shift (0,4,8,16,24,32) */
} xdf_reloc;

typedef struct xdf_section_data {
    /*@dependent@*/ yasm_symrec *sym;	/* symbol created for this section */
    yasm_intnum *addr;	    /* starting memory address */
    long scnum;		    /* section number (0=first section) */
    unsigned int align;	    /* section alignment (0-4096) */
    enum {
	XDF_SECT_ABSOLUTE = 0x01,
	XDF_SECT_FLAT = 0x02,
	XDF_SECT_BSS = 0x04,
	XDF_SECT_EQU = 0x08,
	XDF_SECT_USE_16 = 0x10,
	XDF_SECT_USE_32 = 0x20,
	XDF_SECT_USE_64 = 0x40
    } flags;		    /* section flags */
    unsigned long scnptr;   /* file ptr to raw data */
    unsigned long size;	    /* size of raw data (section data) in bytes */
    unsigned long relptr;   /* file ptr to relocation */
    unsigned long nreloc;   /* number of relocation entries >64k -> error */
    /*@owned@*/ xdf_reloc_head relocs;
} xdf_section_data;

typedef struct xdf_symrec_data {
    unsigned long index;		/* assigned XDF symbol table index */
} xdf_symrec_data;

typedef struct xdf_symtab_entry {
    STAILQ_ENTRY(xdf_symtab_entry) link;
    /*@dependent@*/ yasm_symrec *sym;
} xdf_symtab_entry;
typedef STAILQ_HEAD(xdf_symtab_head, xdf_symtab_entry) xdf_symtab_head;

typedef struct yasm_objfmt_xdf {
    yasm_objfmt_base objfmt;		    /* base structure */

    long parse_scnum;		    /* sect numbering in parser */
    xdf_symtab_head xdf_symtab;	    /* symbol table of indexed syms */

    yasm_object *object;
    yasm_symtab *symtab;
    /*@dependent@*/ yasm_arch *arch;
} yasm_objfmt_xdf;

typedef struct xdf_objfmt_output_info {
    yasm_objfmt_xdf *objfmt_xdf;
    /*@dependent@*/ FILE *f;
    /*@only@*/ unsigned char *buf;
    yasm_section *sect;
    /*@dependent@*/ xdf_section_data *xsd;
} xdf_objfmt_output_info;

static void xdf_section_data_destroy(/*@only@*/ void *d);
static void xdf_section_data_print(void *data, FILE *f, int indent_level);

static const yasm_assoc_data_callback xdf_section_data_cb = {
    xdf_section_data_destroy,
    xdf_section_data_print
};

static void xdf_symrec_data_destroy(/*@only@*/ void *d);
static void xdf_symrec_data_print(void *data, FILE *f, int indent_level);

static const yasm_assoc_data_callback xdf_symrec_data_cb = {
    xdf_symrec_data_destroy,
    xdf_symrec_data_print
};

yasm_objfmt_module yasm_xdf_LTX_objfmt;


static /*@dependent@*/ xdf_symtab_entry *
xdf_objfmt_symtab_append(yasm_objfmt_xdf *objfmt_xdf, yasm_symrec *sym)
{
    /*@null@*/ /*@dependent@*/ xdf_symrec_data *sym_data_prev;
    xdf_symrec_data *sym_data;
    xdf_symtab_entry *entry;
    unsigned long indx;

    if (STAILQ_EMPTY(&objfmt_xdf->xdf_symtab))
	indx = 0;
    else {
	entry = STAILQ_LAST(&objfmt_xdf->xdf_symtab, xdf_symtab_entry, link);
	sym_data_prev = yasm_symrec_get_data(entry->sym, &xdf_symrec_data_cb);
	assert(sym_data_prev != NULL);
	indx = sym_data_prev->index + 1;
    }

    sym_data = yasm_xmalloc(sizeof(xdf_symrec_data));
    sym_data->index = indx;
    yasm_symrec_add_data(sym, &xdf_symrec_data_cb, sym_data);

    entry = yasm_xmalloc(sizeof(xdf_symtab_entry));
    entry->sym = sym;
    STAILQ_INSERT_TAIL(&objfmt_xdf->xdf_symtab, entry, link);

    return entry;
}

static int
xdf_objfmt_append_local_sym(yasm_symrec *sym, /*@unused@*/ /*@null@*/ void *d)
{
    /*@null@*/ yasm_objfmt_xdf *objfmt_xdf = (yasm_objfmt_xdf *)d;
    assert(objfmt_xdf != NULL);
    if (!yasm_symrec_get_data(sym, &xdf_symrec_data_cb))
	xdf_objfmt_symtab_append(objfmt_xdf, sym);
    return 1;
}

static yasm_objfmt *
xdf_objfmt_create(const char *in_filename, yasm_object *object, yasm_arch *a)
{
    yasm_objfmt_xdf *objfmt_xdf = yasm_xmalloc(sizeof(yasm_objfmt_xdf));

    objfmt_xdf->object = object;
    objfmt_xdf->symtab = yasm_object_get_symtab(object);
    objfmt_xdf->arch = a;

    /* Only support x86 arch */
    if (yasm__strcasecmp(yasm_arch_keyword(a), "x86") != 0) {
	yasm_xfree(objfmt_xdf);
	return NULL;
    }

    /* Support x86 and amd64 machines of x86 arch */
    if (yasm__strcasecmp(yasm_arch_get_machine(a), "x86") &&
	yasm__strcasecmp(yasm_arch_get_machine(a), "amd64")) {
	yasm_xfree(objfmt_xdf);
	return NULL;
    }

    objfmt_xdf->parse_scnum = 0;    /* section numbering starts at 0 */
    STAILQ_INIT(&objfmt_xdf->xdf_symtab);

    objfmt_xdf->objfmt.module = &yasm_xdf_LTX_objfmt;

    return (yasm_objfmt *)objfmt_xdf;
}

static int
xdf_objfmt_output_expr(yasm_expr **ep, unsigned char *buf, size_t destsize,
			size_t valsize, int shift, unsigned long offset,
			yasm_bytecode *bc, int rel, int warn,
			/*@null@*/ void *d)
{
    /*@null@*/ xdf_objfmt_output_info *info = (xdf_objfmt_output_info *)d;
    yasm_objfmt_xdf *objfmt_xdf;
    /*@dependent@*/ /*@null@*/ yasm_intnum *intn;
    /*@dependent@*/ /*@null@*/ const yasm_floatnum *flt;
    /*@dependent@*/ /*@null@*/ yasm_symrec *sym;
    yasm_expr *shr_expr;
    yasm_expr *wrt_expr;
    unsigned int shr = 0;
    unsigned int seg = 0;

    assert(info != NULL);
    objfmt_xdf = info->objfmt_xdf;

    *ep = yasm_expr_simplify(*ep, yasm_common_calc_bc_dist);

    /* Handle floating point expressions */
    flt = yasm_expr_get_floatnum(ep);
    if (flt) {
	if (shift < 0)
	    yasm_internal_error(N_("attempting to negative shift a float"));
	return yasm_arch_floatnum_tobytes(objfmt_xdf->arch, flt, buf,
					  destsize, valsize,
					  (unsigned int)shift, warn, bc->line);
    }

    /* Check for a right shift value */
    shr_expr = yasm_expr_extract_shr(ep);
    if (shr_expr) {
	/*@dependent@*/ /*@null@*/ const yasm_intnum *shr_intn;
	shr_intn = yasm_expr_get_intnum(&shr_expr, NULL);
	if (!shr_intn) {
	    yasm__error(bc->line, N_("shift expression too complex"));
	    return 1;
	}
	shr = yasm_intnum_get_uint(shr_intn);
    }

    /* Check for a segment relocation */
    if (yasm_expr_extract_seg(ep))
	seg = 1;

    /* Check for a WRT relocation */
    wrt_expr = yasm_expr_extract_wrt(ep);

    /* Handle integer expressions, with relocation if necessary */
    sym = yasm_expr_extract_symrec(ep, 0, yasm_common_calc_bc_dist);
    if (sym) {
	xdf_reloc *reloc;

	reloc = yasm_xmalloc(sizeof(xdf_reloc));
	reloc->reloc.addr = yasm_intnum_create_uint(bc->offset + offset);
	reloc->reloc.sym = sym;
	reloc->base = NULL;
	reloc->size = valsize/8;
	reloc->shift = shr;

	if (seg)
	    reloc->type = XDF_RELOC_SEG;
	else if (wrt_expr) {
	    reloc->base = yasm_expr_extract_symrec(&wrt_expr, 0,
						   yasm_common_calc_bc_dist);
	    if (!reloc->base) {
		yasm__error(bc->line, N_("WRT expression too complex"));
		return 1;
	    }
	    reloc->type = XDF_RELOC_WRT;
	} else if (rel) {
	    reloc->type = XDF_RELOC_RIP;
	    /* Need to reference to start of section, so add $$ in. */
	    *ep = yasm_expr_create(YASM_EXPR_ADD, yasm_expr_expr(*ep),
		yasm_expr_sym(yasm_symtab_define_label2("$$",
		    yasm_section_bcs_first(info->sect), 0, (*ep)->line)),
		(*ep)->line);
	    *ep = yasm_expr_simplify(*ep, yasm_common_calc_bc_dist);
	} else
	    reloc->type = XDF_RELOC_REL;
	info->xsd->nreloc++;
	yasm_section_add_reloc(info->sect, (yasm_reloc *)reloc, yasm_xfree);
    }
    intn = yasm_expr_get_intnum(ep, NULL);
    if (intn) {
	if (rel) {
	    int retval = yasm_arch_intnum_fixup_rel(objfmt_xdf->arch, intn,
						    valsize, bc, bc->line);
	    if (retval)
		return retval;
	}
	return yasm_arch_intnum_tobytes(objfmt_xdf->arch, intn, buf, destsize,
					valsize, shift, bc, warn, bc->line);
    }

    /* Check for complex float expressions */
    if (yasm_expr__contains(*ep, YASM_EXPR_FLOAT)) {
	yasm__error(bc->line, N_("floating point expression too complex"));
	return 1;
    }

    yasm__error(bc->line, N_("xdf: relocation too complex"));
    return 1;
}

static int
xdf_objfmt_output_bytecode(yasm_bytecode *bc, /*@null@*/ void *d)
{
    /*@null@*/ xdf_objfmt_output_info *info = (xdf_objfmt_output_info *)d;
    /*@null@*/ /*@only@*/ unsigned char *bigbuf;
    unsigned long size = REGULAR_OUTBUF_SIZE;
    unsigned long multiple;
    unsigned long i;
    int gap;

    assert(info != NULL);

    bigbuf = yasm_bc_tobytes(bc, info->buf, &size, &multiple, &gap, info,
			     xdf_objfmt_output_expr, NULL);

    /* Don't bother doing anything else if size ended up being 0. */
    if (size == 0) {
	if (bigbuf)
	    yasm_xfree(bigbuf);
	return 0;
    }

    info->xsd->size += multiple*size;

    /* Warn that gaps are converted to 0 and write out the 0's. */
    if (gap) {
	unsigned long left;
	yasm__warning(YASM_WARN_GENERAL, bc->line,
	    N_("uninitialized space: zeroing"));
	/* Write out in chunks */
	memset(info->buf, 0, REGULAR_OUTBUF_SIZE);
	left = multiple*size;
	while (left > REGULAR_OUTBUF_SIZE) {
	    fwrite(info->buf, REGULAR_OUTBUF_SIZE, 1, info->f);
	    left -= REGULAR_OUTBUF_SIZE;
	}
	fwrite(info->buf, left, 1, info->f);
    } else {
	/* Output multiple copies of buf (or bigbuf if non-NULL) to file */
	for (i=0; i<multiple; i++)
	    fwrite(bigbuf ? bigbuf : info->buf, (size_t)size, 1, info->f);
    }

    /* If bigbuf was allocated, free it */
    if (bigbuf)
	yasm_xfree(bigbuf);

    return 0;
}

static int
xdf_objfmt_output_section(yasm_section *sect, /*@null@*/ void *d)
{
    /*@null@*/ xdf_objfmt_output_info *info = (xdf_objfmt_output_info *)d;
    /*@dependent@*/ /*@null@*/ xdf_section_data *xsd;
    long pos;
    xdf_reloc *reloc;
    yasm_bytecode *last;

    /* FIXME: Don't output absolute sections into the section table */
    if (yasm_section_is_absolute(sect))
	return 0;

    assert(info != NULL);
    xsd = yasm_section_get_data(sect, &xdf_section_data_cb);
    assert(xsd != NULL);

    last = yasm_section_bcs_last(sect);
    if (xsd->flags & XDF_SECT_BSS) {
	/* Don't output BSS sections.
	 * TODO: Check for non-reserve bytecodes?
	 */
	pos = 0;    /* position = 0 because it's not in the file */
	xsd->size = last->offset + last->len;
    } else {
	pos = ftell(info->f);
	if (pos == -1) {
	    yasm__fatal(N_("could not get file position on output file"));
	    /*@notreached@*/
	    return 1;
	}

	info->sect = sect;
	info->xsd = xsd;
	yasm_section_bcs_traverse(sect, info, xdf_objfmt_output_bytecode);

	/* Sanity check final section size */
	if (xsd->size != (last->offset + last->len))
	    yasm_internal_error(
		N_("xdf: section computed size did not match actual size"));
    }

    /* Empty?  Go on to next section */
    if (xsd->size == 0)
	return 0;

    xsd->scnptr = (unsigned long)pos;

    /* No relocations to output?  Go on to next section */
    if (xsd->nreloc == 0)
	return 0;

    pos = ftell(info->f);
    if (pos == -1) {
	yasm__fatal(N_("could not get file position on output file"));
	/*@notreached@*/
	return 1;
    }
    xsd->relptr = (unsigned long)pos;

    reloc = (xdf_reloc *)yasm_section_relocs_first(sect);
    while (reloc) {
	unsigned char *localbuf = info->buf;
	/*@null@*/ xdf_symrec_data *xsymd;

	xsymd = yasm_symrec_get_data(reloc->reloc.sym, &xdf_symrec_data_cb);
	if (!xsymd)
	    yasm_internal_error(
		N_("xdf: no symbol data for relocated symbol"));

	yasm_intnum_get_sized(reloc->reloc.addr, localbuf, 4, 32, 0, 0, 0, 0);
	localbuf += 4;				/* address of relocation */
	YASM_WRITE_32_L(localbuf, xsymd->index);    /* relocated symbol */
	if (reloc->base) {
	    xsymd = yasm_symrec_get_data(reloc->base, &xdf_symrec_data_cb);
	    if (!xsymd)
		yasm_internal_error(
		    N_("xdf: no symbol data for relocated base symbol"));
	    YASM_WRITE_32_L(localbuf, xsymd->index); /* base symbol */
	} else {
	    if (reloc->type == XDF_RELOC_WRT)
		yasm_internal_error(
		    N_("xdf: no base symbol for WRT relocation"));
	    YASM_WRITE_32_L(localbuf, 0);	    /* no base symbol */
	}
	YASM_WRITE_8(localbuf, reloc->type);	    /* type of relocation */
	YASM_WRITE_8(localbuf, reloc->size);	    /* size of relocation */
	YASM_WRITE_8(localbuf, reloc->shift);	    /* relocation shift */
	YASM_WRITE_8(localbuf, 0);		    /* flags */
	fwrite(info->buf, 16, 1, info->f);

	reloc = (xdf_reloc *)yasm_section_reloc_next((yasm_reloc *)reloc);
    }

    return 0;
}

static int
xdf_objfmt_output_secthead(yasm_section *sect, /*@null@*/ void *d)
{