/*
* Section utility functions
*
* 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:
* 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 <limits.h>
#include "libyasm-stdint.h"
#include "coretype.h"
#include "hamt.h"
#include "valparam.h"
#include "assocdat.h"
#include "linemap.h"
#include "errwarn.h"
#include "intnum.h"
#include "expr.h"
#include "value.h"
#include "symrec.h"
#include "bytecode.h"
#include "arch.h"
#include "section.h"
#include "dbgfmt.h"
#include "objfmt.h"
#include "inttree.h"
struct yasm_section {
/*@reldef@*/ STAILQ_ENTRY(yasm_section) link;
/*@dependent@*/ yasm_object *object; /* Pointer to parent object */
/*@owned@*/ char *name; /* strdup()'ed name (given by user) */
/* associated data; NULL if none */
/*@null@*/ /*@only@*/ yasm__assoc_data *assoc_data;
unsigned long align; /* Section alignment */
unsigned long opt_flags; /* storage for optimizer flags */
int code; /* section contains code (instructions) */
int res_only; /* allow only resb family of bytecodes? */
int def; /* "default" section, e.g. not specified by
using section directive */
/* the bytecodes for the section's contents */
/*@reldef@*/ STAILQ_HEAD(yasm_bytecodehead, yasm_bytecode) bcs;
/* the relocations for the section */
/*@reldef@*/ STAILQ_HEAD(yasm_relochead, yasm_reloc) relocs;
void (*destroy_reloc) (/*@only@*/ void *reloc);
};
static void yasm_section_destroy(/*@only@*/ yasm_section *sect);
/* Wrapper around directive for HAMT insertion */
typedef struct yasm_directive_wrap {
const yasm_directive *directive;
} yasm_directive_wrap;
/*
* Standard "builtin" object directives.
*/
static void
dir_extern(yasm_object *object, yasm_valparamhead *valparams,
yasm_valparamhead *objext_valparams, unsigned long line)
{
yasm_valparam *vp = yasm_vps_first(valparams);
yasm_symrec *sym;
sym = yasm_symtab_declare(object->symtab, yasm_vp_id(vp), YASM_SYM_EXTERN,
line);
if (objext_valparams) {
yasm_valparamhead *vps = yasm_vps_create();
*vps = *objext_valparams; /* structure copy */
yasm_vps_initialize(objext_valparams); /* don't double-free */
yasm_symrec_set_objext_valparams(sym, vps);
}
}
static void
dir_global(yasm_object *object, yasm_valparamhead *valparams,
yasm_valparamhead *objext_valparams, unsigned long line)
{
yasm_valparam *vp = yasm_vps_first(valparams);
yasm_symrec *sym;
sym = yasm_symtab_declare(object->symtab, yasm_vp_id(vp), YASM_SYM_GLOBAL,
line);
if (objext_valparams) {
yasm_valparamhead *vps = yasm_vps_create();
*vps = *objext_valparams; /* structure copy */
yasm_vps_initialize(objext_valparams); /* don't double-free */
yasm_symrec_set_objext_valparams(sym, vps);
}
}
static void
dir_common(yasm_object *object, yasm_valparamhead *valparams,
yasm_valparamhead *objext_valparams, unsigned long line)
{
yasm_valparam *vp = yasm_vps_first(valparams);
yasm_valparam *vp2 = yasm_vps_next(vp);
yasm_expr *size = yasm_vp_expr(vp2, object->symtab, line);
yasm_symrec *sym;
if (!size) {
yasm_error_set(YASM_ERROR_SYNTAX,
N_("no size specified in %s declaration"), "COMMON");
return;
}
sym = yasm_symtab_declare(object->symtab, yasm_vp_id(vp), YASM_SYM_COMMON,
line);
yasm_symrec_set_common_size(sym, size);
if (objext_valparams) {
yasm_valparamhead *vps = yasm_vps_create();
*vps = *objext_valparams; /* structure copy */
yasm_vps_initialize(objext_valparams); /* don't double-free */
yasm_symrec_set_objext_valparams(sym, vps);
}
}
static void
dir_section(yasm_object *object, yasm_valparamhead *valparams,
yasm_valparamhead *objext_valparams, unsigned long line)
{
yasm_section *new_section =
yasm_objfmt_section_switch(object, valparams, objext_valparams, line);
if (new_section)
object->cur_section = new_section;
else
yasm_error_set(YASM_ERROR_SYNTAX,
N_("invalid argument to directive `%s'"), "SECTION");
}
static const yasm_directive object_directives[] = {
{ ".extern", "gas", dir_extern, YASM_DIR_ID_REQUIRED },
{ ".global", "gas", dir_global, YASM_DIR_ID_REQUIRED },
{ ".globl", "gas", dir_global, YASM_DIR_ID_REQUIRED },
{ "extern", "nasm", dir_extern, YASM_DIR_ID_REQUIRED },
{ "global", "nasm", dir_global, YASM_DIR_ID_REQUIRED },
{ "common", "nasm", dir_common, YASM_DIR_ID_REQUIRED },
{ "section", "nasm", dir_section, YASM_DIR_ARG_REQUIRED },
{ "segment", "nasm", dir_section, YASM_DIR_ARG_REQUIRED },
{ NULL, NULL, NULL, 0 }
};
static void
directive_level2_delete(/*@only@*/ void *data)
{
yasm_xfree(data);
}
static void
directive_level1_delete(/*@only@*/ void *data)
{
HAMT_destroy(data, directive_level2_delete);
}
static void
directives_add(yasm_object *object, /*@null@*/ const yasm_directive *dir)
{
if (!dir)
return;
while (dir->name) {
HAMT *level2 = HAMT_search(object->directives, dir->parser);
int replace;
yasm_directive_wrap *wrap = yasm_xmalloc(sizeof(yasm_directive_wrap));
if (!level2) {
replace = 0;
level2 = HAMT_insert(object->directives, dir->parser,
HAMT_create(1, yasm_internal_error_),
&replace, directive_level1_delete);
}
replace = 0;
wrap->directive = dir;
HAMT_insert(level2, dir->name, wrap, &replace,
directive_level2_delete);
dir++;
}
}
/*@-compdestroy@*/
yasm_object *
yasm_object_create(const char *src_filename, const char *obj_filename,
/*@kept@*/ yasm_arch *arch,
const yasm_objfmt_module *objfmt_module,
const yasm_dbgfmt_module *dbgfmt_module)
{
yasm_object *object = yasm_xmalloc(sizeof(yasm_object));
int matched, i;
object->src_filename = yasm__xstrdup(src_filename);
object->deb_filename = NULL;
object->obj_filename = yasm__xstrdup(obj_filename);
/* No prefix/suffix */
object->global_prefix = yasm__xstrdup("");
object->global_suffix = yasm__xstrdup("");
/* Create empty symbol table */
object->symtab = yasm_symtab_create();
/* Initialize sections linked list */
STAILQ_INIT(&object->sections);
/* Create directives HAMT */
object->directives = HAMT_create(1, yasm_internal_error_);
/* Initialize the target architecture */
object->arch = arch;
/* Initialize things to NULL in case of error */
object->dbgfmt = NULL;
/* Initialize the object format */
object->objfmt = yasm_objfmt_create(objfmt_module, object);
if (!object->objfmt) {
yasm_error_set(YASM_ERROR_GENERAL,
N_("object format `%s' does not support architecture `%s' machine `%s'"),
objfmt_module->keyword, ((yasm_arch_base *)arch)->module->keyword,
yasm_arch_get_machine(arch));
goto error;
}
/* Get a fresh copy of objfmt_module as it may have changed. */
objfmt_module = ((yasm_objfmt_base *)object->objfmt)->module;
/* Add an initial "default" section to object */
object->cur_section = yasm_objfmt_add_default_section(object);
/* Check to see if the requested debug format is in the allowed list
* for the active object format.
*/
matched = 0;
for (i=0; objfmt_module->dbgfmt_keywords[i]; i++) {
if (yasm__strcasecmp(objfmt_module->dbgfmt_keywords[i],
dbgfmt_module->keyword) == 0) {
matched = 1;
break;
}
}
if (!matched) {
yasm_error_set(YASM_ERROR_GENERAL,
N_("`%s' is not a valid debug format for object format `%s'"),
dbgfmt_module->keyword, objfmt_module->keyword);
goto error;
}
/* Initialize the debug format */
object->dbgfmt = yasm_dbgfmt_create(dbgfmt_module, object);
if (!object->dbgfmt) {
yasm_error_set(YASM_ERROR_GENERAL,
N_("debug format `%s' does not work with object format `%s'"),
dbgfmt_module->keyword, objfmt_module->keyword);
goto error;
}
/* Add directives to HAMT. Note ordering here determines priority. */
directives_add(object,
((yasm_objfmt_base *)object->objfmt)->module->directives);
directives_add(object,
((yasm_dbgfmt_base *)object->dbgfmt)->module->directives);
directives_add(object,
((yasm_arch_base *)object->arch)->module->directives);
directives_add(object, object_directives);
return object;
error:
yasm_object_destroy(object);
return NULL;
}
/*@=compdestroy@*/
/*@-onlytrans@*/
yasm_section *
yasm_object_get_general(yasm_object *object, const char *name,
unsigned long align, int code, int res_only,
int *isnew, unsigned long line)
{
yasm_section *s;
yasm_bytecode *bc;
/* Search through current sections to see if we already have one with
* that name.
*/
STAILQ_FOREACH(s, &object->sections, link) {
if (strcmp(s->name, name) == 0) {
*isnew = 0;
return s;
}
}
/* No: we have to allocate and create a new one. */
/* Okay, the name is valid; now allocate and initialize */
s = yasm_xcalloc(1, sizeof(yasm_section));
STAILQ_INSERT_TAIL(&object->sections, s, link);
s->object = object;
s->name = yasm__xstrdup(name);
s->assoc_data = NULL;
s->align = align;
/* Initialize bytecodes with one empty bytecode (acts as "prior" for first
* real bytecode in section.
*/
STAILQ_INIT(&s->bcs);
bc = yasm_bc_create_common(NULL, NULL, 0);
bc->section = s;
bc->offset = 0;
STAILQ_INSERT_TAIL(&s->bcs, bc, link);
/* Initialize relocs */
STAILQ_INIT(&s->relocs);
s->destroy_reloc = NULL;
s->code = code;
s->res_only = res_only;
s->def = 0;
/* Initialize object format specific data */
yasm_objfmt_init_new_section(s, line);
*isnew = 1;
return s;
}
/*@=onlytrans@*/
int
yasm_object_directive(yasm_object *object, const char *name,
const char *parser, yasm_valparamhead *valparams,
yasm_valparamhead *objext_valparams,
unsigned long line)
{
HAMT *level2;
yasm_directive_wrap *wrap;
level2 = HAMT_search(object->directives, parser);
if (!level2)
return 1;
wrap = HAMT_search(level2, name);
if (!wrap)
return 1;
yasm_call_directive(wrap->directive, object, valparams, objext_valparams,
line);
return 0;
}
void
yasm_object_set_source_fn(yasm_object *object, const char *src_filename)
{
yasm_xfree(object->src_filename);
object->src_filename = yasm__xstrdup(src_filename);
yasm_xfree(object->deb_filename);
object->deb_filename = NULL;
}
void
yasm_object_set_global_prefix(yasm_object *object, const char *prefix)
{
yasm_xfree(object->global_prefix);
object->global_prefix = yasm__xstrdup(prefix);
}
void
yasm_object_set_global_suffix(yasm_object *object, const char *suffix)
{
yasm_xfree(object->global_suffix);
object->global_suffix = yasm__xstrdup(suffix);
}
int
yasm_section_is_code(yasm_section *sect)
{
return sect->code;
}
unsigned long
yasm_section_get_opt_flags(const yasm_section *sect)
{
return sect->opt_flags;
}
void
yasm_section_set_opt_flags(yasm_section *sect, unsigned long opt_flags)
{
sect->opt_flags = opt_flags;
}
int
yasm_section_is_default(const yasm_section *sect)
{
return sect->def;
}
void
yasm_section_set_default(yasm_section *sect, int def)
{
sect->def = def;
}
yasm_object *
yasm_section_get_object(const yasm_section *sect)
{
return sect->object;
}
void *
yasm_section_get_data(yasm_section *sect,
const yasm_assoc_data_callback *callback)
{
return yasm__assoc_data_get(sect->assoc_data, callback);
}
void
yasm_section_add_data(yasm_section *sect,
const yasm_assoc_data_callback *callback, void *data)
{
sect->assoc_data = yasm__assoc_data_add(sect->assoc_data, callback, data);
}
void
yasm_object_destroy(yasm_object *object)
{
yasm_section *cur, *next;
/* Delete object format, debug format, and arch. This can be called
* due to an error in yasm_object_create(), so look out for NULLs.
*/
if (object->objfmt)
yasm_objfmt_destroy(object->objfmt);
if (object->dbgfmt)
yasm_dbgfmt_destroy(object->dbgfmt);
/* Delete sections */
cur = STAILQ_FIRST(&object->sections);
while (cur) {
next = STAILQ_NEXT(cur, link);
yasm_section_destroy(cur);
cur = next;
}
/* Delete directives HAMT */
HAMT_destroy(object->directives, directive_level1_delete);
/* Delete prefix/suffix */
yasm_xfree(object->global_prefix);
yasm_xfree(object->global_suffix);
/* Delete associated filenames */
yasm_xfree(object->src_filename);
yasm_xfree(object->deb_filename);
yasm_xfree(object->obj_filename);
/* Delete symbol table */
yasm_symtab_destroy(object->symtab);
/* Delete architecture */
if (object->arch)
yasm_arch_destroy(object->arch);
yasm_xfree(object);
}
void
yasm_object_print(const yasm_object *object, FILE *f, int indent_level)
{
yasm_section *cur;
/* Print symbol table */
fprintf(f, "%*sSymbol Table:\n", indent_level, "");
yasm_symtab_print(object->symtab, f, indent_level+1);
/* Print sections and bytecodes */
STAILQ_FOREACH(cur, &object->sections, link) {
fprintf(f, "%*sSection:\n", indent_level, "");
yasm_section_print(cur, f, indent_level+1, 1);
}
}
void
yasm_object_finalize(yasm_object *object, yasm_errwarns *errwarns)
{
yasm_section *sect;
/* Iterate through sections */
STAILQ_FOREACH(sect, &object->sections, link) {
yasm_bytecode *cur = STAILQ_FIRST(§->bcs);
yasm_bytecode *prev;
/* Skip our locally created empty bytecode first. */
prev = cur;
cur = STAILQ_NEXT(cur, link);
/* Iterate through the remainder, if any. */
while (cur) {
/* Finalize */
yasm_bc_finalize(cur, prev);
yasm_errwarn_propagate(errwarns, cur->line);
prev = cur;
cur = STAILQ_NEXT(cur, link);
}
}
}
int
yasm_object_sections_traverse(yasm_object *object, /*@null@*/ void *d,
int (*func) (yasm_section *sect,
/*@null@*/ void *d))
{
yasm_section *cur;
STAILQ_FOREACH(cur, &object->sections, link) {
int retval = func(cur, d);
if (retval != 0)
return retval;
}
return 0;
}
/*@-onlytrans@*/
yasm_section *
yasm_object_find_general(yasm_object *object, const char *name)
{
yasm_section *cur;
STAILQ_FOREACH(cur, &object->sections, link) {
if (strcmp(cur->name, name) == 0)
return cur;
}
return NULL;
}
/*@=onlytrans@*/
void
yasm_section_add_reloc(yasm_section *sect, yasm_reloc *reloc,
void (*destroy_func) (/*@only@*/ void *reloc))
{
STAILQ_INSERT_TAIL(§->relocs, reloc, link);
if (!destroy_func)
yasm_internal_error(N_("NULL destroy function given to add_reloc"));
else if (sect->destroy_reloc && destroy_func != sect->destroy_reloc)
yasm_internal_error(N_("different destroy function given to add_reloc"));
sect->destroy_reloc = destroy_func;
}
/*@null@*/ yasm_reloc *
yasm_section_relocs_first(yasm_section *sect)
{
return STAILQ_FIRST(§->relocs);
}
#undef yasm_section_reloc_next
/*@null@*/ yasm_reloc *
yasm_section_reloc_next(yasm_reloc *reloc)
{
return STAILQ_NEXT(reloc, link);
}
void
yasm_reloc_get(yasm_reloc *reloc, yasm_intnum **addrp, yasm_symrec **symp)
{
*addrp = reloc->addr;
*symp = reloc->sym;
}
yasm_bytecode *
yasm_section_bcs_first(yasm_section *sect)
{
return STAILQ_FIRST(§->bcs);
}
yasm_bytecode *
yasm_section_bcs_last(yasm_section *sect)
{
return STAILQ_LAST(§->bcs, yasm_bytecode, link);
}
yasm_bytecode *
yasm_section_bcs_append(yasm_section *sect, yasm_bytecode *bc)
{
if (bc) {
if (bc->callback) {
bc->section = sect; /* record parent section */
STAILQ_INSERT_TAIL(§->bcs, bc, link);
return bc;
} else
yasm_xfree(bc);
}
return (yasm_bytecode *)NULL;
}
int
yasm_section_bcs_traverse(yasm_section *sect,
/*@null@*/ yasm_errwarns *errwarns,
/*@null@*/ void *d,
int (*func) (yasm_bytecode *bc, /*@null@*/ void *d))
{
yasm_bytecode *cur = STAILQ_FIRST(§->bcs);
/* Skip our locally created empty bytecode first. */
cur = STAILQ_NEXT(cur, link);
/* Iterate through the remainder, if any. */
while (cur) {
int retval = func(cur, d);
if (errwarns)
yasm_errwarn_propagate(errwarns, cur->line);
if (retval != 0)
return retval;
cur = STAILQ_NEXT(cur, link);
}
return 0;
}
const char *
yasm_section_get_name(const yasm_section *sect)
{
return sect->name;
}
void
yasm_section_set_align(yasm_section *sect, unsigned long align,
unsigned long line)
{
sect->align = align;
}
unsigned long
yasm_section_get_align(const yasm_section *sect)
{
return sect->align;
}
static void
yasm_section_destroy(yasm_section *sect)
{
yasm_bytecode *cur, *next;
yasm_reloc *r_cur, *r_next;
if (!sect)
return;
yasm_xfree(sect->name);
yasm__assoc_data_destroy(sect->assoc_data);
/* Delete bytecodes */
cur = STAILQ_FIRST(§->bcs);
while (cur) {
next = STAILQ_NEXT(cur, link);
yasm_bc_destroy(cur);
cur = next;
}
/* Delete relocations */
r_cur = STAILQ_FIRST(§->relocs);
while (r_cur) {
r_next = STAILQ_NEXT(r_cur, link);
yasm_intnum_destroy(r_cur->addr);
sect->destroy_reloc(r_cur);
r_cur = r_next;
}
yasm_xfree(sect);
}
void
yasm_section_print(const yasm_section *sect, FILE *f, int indent_level,
int print_bcs)
{
if (!sect) {
fprintf(f, "%*s(none)\n", indent_level, "");
return;
}
fprintf(f, "%*sname=%s\n", indent_level, "", sect->name);
if (sect->assoc_data) {
fprintf(f, "%*sAssociated data:\n", indent_level, "");
yasm__assoc_data_print(sect->assoc_data, f, indent_level+1);
}
if (print_bcs) {
yasm_bytecode *cur;
fprintf(f, "%*sBytecodes:\n", indent_level, "");
STAILQ_FOREACH(cur, §->bcs, link) {
fprintf(f, "%*sNext Bytecode:\n", indent_level+1, "");
yasm_bc_print(cur, f, indent_level+2);
}
}
}
/*
* Robertson (1977) optimizer
* Based (somewhat loosely) on the algorithm given in:
* MRC Technical Summary Report # 1779
* CODE GENERATION FOR SHORT/LONG ADDRESS MACHINES
* Edward L. Robertson
* Mathematics Research Center
* University of Wisconsin-Madison
* 610 Walnut Street
* Madison, Wisconsin 53706
* August 1977
*
* Key components of algorithm:
* - start assuming all short forms
* - build spans for short->long transition dependencies
* - if a long form is needed, walk the dependencies and update
* Major differences from Robertson's algorithm:
* - detection of cycles
* - any difference of two locations is allowed
* - handling of alignment/org gaps (offset setting)
* - handling of multiples
*
* Data structures:
* - Interval tree to store spans and associated data
* - Queues QA and QB
*
* Each span keeps track of:
* - Associated bytecode (bytecode that depends on the span length)
* - Active/inactive state (starts out active)
* - Sign (negative/positive; negative being "backwards" in address)
* - Current length in bytes
* - New length in bytes
* - Negative/Positive thresholds
* - Span ID (unique within each bytecode)
*
* How org and align and any other offset-based bytecodes are handled:
*
* Some portions are critical values that must not depend on any bytecode
* offset (either relative or absolute).
*
* All offset-setters (ORG and ALIGN) are put into a linked list in section
* order (e.g. increasing offset order). Each span keeps track of the next
* offset-setter following the span's associated bytecode.
*
* When a bytecode is expanded, the next offset-setter is examined. The
* offset-setter may be able to absorb the expansion (e.g. any offset
* following it would not change), or it may have to move forward (in the
* case of align) or error (in the case of org). If it has to move forward,
* following offset-setters must also be examined for absorption or moving
* forward. In either case, the ongoing offset is updated as well as the
* lengths of any spans dependent on the offset-setter.
*
* Alignment/ORG value is critical value.
* Cannot be combined with TIMES.
*
* How times is handled:
*
* TIMES: Handled separately from bytecode "raw" size. If not span-dependent,
* trivial (just multiplied in at any bytecode size increase). Span
* dependent times update on any change (span ID 0). If the resultant
* next bytecode offset would be less than the old next bytecode offset,
* error. Otherwise increase offset and update dependent spans.
*
* To reduce interval tree size, a first expansion pass is performed
* before the spans are added to the tree.
*
* Basic algorithm outline:
*
* 1. Initialization:
* a. Number bytecodes sequentially (via bc_index) and calculate offsets
* of all bytecodes assuming minimum length, building a list of all
* dependent spans as we go.
* "minimum" here means absolute minimum:
* - align/org (offset-based) bumps offset as normal
* - times values (with span-dependent values) assumed to be 0
* b. Iterate over spans. Set span length based on bytecode offsets
* determined in 1a. If span is "certainly" long because the span
* is an absolute reference to another section (or external) or the
* distance calculated based on the minimum length is greater than the
* span's threshold, expand the span's bytecode, and if no further
* expansion can result, mark span as inactive.
* c. Iterate over bytecodes to update all bytecode offsets based on new
* (expanded) lengths calculated in 1b.
* d. Iterate over active spans. Add span to interval tree. Update span's
* length based on new bytecode offsets determined in 1c. If span's
* length exceeds long threshold, add that span to Q.
* 2. Main loop:
* While Q not empty:
* Expand BC dependent on span at head of Q (and remove span from Q).
* Update span:
* If BC no longer dependent on span, mark span as inactive.
* If BC has new thresholds for span, update span.
* If BC increased in size, for each active span that contains BC:
* Increase span length by difference between short and long BC length.
* If span exceeds long threshold (or is flagged to recalculate on any
* change), add it to tail of Q.
* 3. Final pass over bytecodes to generate final offsets.
*/
typedef struct yasm_span yasm_span;
typedef struct yasm_offset_setter {
/* Linked list in section order (e.g. offset order) */
/*@reldef@*/ STAILQ_ENTRY(yasm_offset_setter) link;
/*@dependent@*/ yasm_bytecode *bc;
unsigned long cur_val, new_val;
unsigned long thres;
} yasm_offset_setter;
typedef struct yasm_span_term {
yasm_bytecode *precbc, *precbc2;
yasm_span *span; /* span this term is a member of */
long cur_val, new_val;
unsigned int subst;
} yasm_span_term;
struct yasm_span {
/*@reldef@*/ TAILQ_ENTRY(yasm_span) link; /* for allocation tracking */
/*@reldef@*/ STAILQ_ENTRY(yasm_span) linkq; /* for Q */
/*@dependent@*/ yasm_bytecode *bc;
yasm_value depval;
/* span term for relative portion of value */
yasm_span_term *rel_term;
/* span terms in absolute portion of value */
yasm_span_term *terms;
yasm_expr__item *items;
unsigned int num_terms;
long cur_val;
long new_val;
long neg_thres;
long pos_thres;
int id;
int active;
/* NULL-terminated array of spans that led to this span. Used only for
* checking for circular references (cycles) with id=0 spans.
*/
yasm_span **backtrace;
int backtrace_size;
/* First offset setter following this span's bytecode */
yasm_offset_setter *os;
};
typedef struct optimize_data {
/*@reldef@*/ TAILQ_HEAD(yasm_span_head, yasm_span) spans;
/*@reldef@*/ STAILQ_HEAD(yasm_span_shead, yasm_span) QA, QB;
/*@only@*/ IntervalTree *itree;
/*@reldef@*/ STAILQ_HEAD(offset_setters_head, yasm_offset_setter)
offset_setters;
long len_diff; /* used only for optimize_term_expand */
yasm_span *span; /* used only for check_cycle */
yasm_offset_setter *os;
} optimize_data;
static yasm_span *
create_span(yasm_bytecode *bc, int id, /*@null@*/ const yasm_value *value,
long neg_thres, long pos_thres, yasm_offset_setter *os)
{
yasm_span *span = yasm_xmalloc(sizeof(yasm_span));
span->bc = bc;
if (value)
yasm_value_init_copy(&span->depval, value);
else
yasm_value_initialize(&span->depval, NULL, 0);
span->rel_term = NULL;
span->terms = NULL;
span->items = NULL;
span->num_terms = 0;
span->cur_val = 0;
span->new_val = 0;
span->neg_thres = neg_thres;
span->pos_thres = pos_thres;
span->id = id;
span->active = 1;
span->backtrace = NULL;
span->backtrace_size = 0;
span->os = os;
return span;
}
static void
optimize_add_span(void *add_span_data, yasm_bytecode *bc, int id,
const yasm_value *value, long neg_thres, long pos_thres)
{
optimize_data *optd = (optimize_data *)add_span_data;
yasm_span *span;
span = create_span(bc, id, value, neg_thres, pos_thres, optd->os);
TAILQ_INSERT_TAIL(&optd->spans, span, link);
}
static void
add_span_term(unsigned int subst, yasm_bytecode *precbc,
yasm_bytecode *precbc2, void *d)
{
yasm_span *span = d;
yasm_intnum *intn;
if (subst >= span->num_terms) {
/* Linear expansion since total number is essentially always small */
span->num_terms = subst+1;
span->terms = yasm_xrealloc(span->terms,
span->num_terms*sizeof(yasm_span_term));
}
span->terms[subst].precbc = precbc;
span->terms[subst].precbc2 = precbc2;
span->terms[subst].span = span;
span->terms[subst].subst = subst;
intn = yasm_calc_bc_dist(precbc, precbc2);
if (!intn)
yasm_internal_error(N_("could not calculate bc distance"));
span->terms[subst].cur_val = 0;
span->terms[subst].new_val = yasm_intnum_get_int(intn);
yasm_intnum_destroy(intn);
}
static void
span_create_terms(yasm_span *span)
{
unsigned int i;
/* Split out sym-sym terms in absolute portion of dependent value */
if (span->depval.abs) {
span->num_terms = yasm_expr__bc_dist_subst(&span->depval.abs, span,
add_span_term);
if (span->num_terms > 0) {
span->items = yasm_xmalloc(span->num_terms*sizeof(yasm_expr__item));
for (i=0; i<span->num_terms; i++) {
/* Create items with dummy value */
span->items[i].type = YASM_EXPR_INT;
span->items[i].data.intn = yasm_intnum_create_int(0);
/* Check for circular references */
if (span->id <= 0 &&
((span->bc->bc_index > span->terms[i].precbc->bc_index &&
span->bc->bc_index <= span->terms[i].precbc2->bc_index) ||
(span->bc->bc_index > span->terms[i].precbc2->bc_index &&
span->bc->bc_index <= span->terms[i].precbc->bc_index)))
yasm_error_set(YASM_ERROR_VALUE,
N_("circular reference detected"));
}
}
}
/* Create term for relative portion of dependent value */
if (span->depval.rel) {
yasm_bytecode *rel_precbc;
int sym_local;
sym_local = yasm_symrec_get_label(span->depval.rel, &rel_precbc);
if (span->depval.wrt || span->depval.seg_of || span->depval.section_rel
|| !sym_local)
return; /* we can't handle SEG, WRT, or external symbols */
if (rel_precbc->section != span->bc->section)
return; /* not in this section */
if (!span->depval.curpos_rel)
return; /* not PC-relative */
span->rel_term = yasm_xmalloc(sizeof(yasm_span_term));
span->rel_term->precbc = NULL;
span->rel_term->precbc2 = rel_precbc;
span->rel_term->span = span;
span->rel_term->subst = ~0U;
span->rel_term->cur_val = 0;
span->rel_term->new_val = yasm_bc_next_offset(rel_precbc) -
span->bc->offset;
}
}
/* Recalculate span value based on current span replacement values.
* Returns 1 if span needs expansion (e.g. exceeded thresholds).
*/
static int
recalc_normal_span(yasm_span *span)
{
span->new_val = 0;
if (span->depval.abs) {
yasm_expr *abs_copy = yasm_expr_copy(span->depval.abs);
/*@null@*/ /*@dependent@*/ yasm_intnum *num;
/* Update sym-sym terms and substitute back into expr */
unsigned int i;
for (i=0; i<span->num_terms; i++)
yasm_intnum_set_int(span->items[i].data.intn,
span->terms[i].new_val);
yasm_expr__subst(abs_copy, span->num_terms, span->items);
num = yasm_expr_get_intnum(&abs_copy, 0);
if (num)
span->new_val = yasm_intnum_get_int(num);
else
span->new_val = LONG_MAX; /* too complex; force to longest form */
yasm_expr_destroy(abs_copy);
}
if (span->rel_term) {
if (span->new_val != LONG_MAX && span->rel_term->new_val != LONG_MAX)
span->new_val += span->rel_term->new_val >> span->depval.rshift;
else
span->new_val = LONG_MAX; /* too complex; force to longest form */
} else if (span->depval.rel)
span->new_val = LONG_MAX; /* too complex; force to longest form */
if (span->new_val == LONG_MAX)
span->active = 0;
/* If id<=0, flag update on any change */
if (span->id <= 0)
return (span->new_val != span->cur_val);
return (span->new_val < span->neg_thres
|| span->new_val > span->pos_thres);
}
/* Updates all bytecode offsets. For offset-based bytecodes, calls expand
* to determine new length.
*/
static int
update_all_bc_offsets(yasm_object *object, yasm_errwarns *errwarns)
{
yasm_section *sect;
int saw_error = 0;
STAILQ_FOREACH(sect, &object->sections, link) {
unsigned long offset = 0;
yasm_bytecode *bc = STAILQ_FIRST(§->bcs);
yasm_bytecode *prevbc;
/* Skip our locally created empty bytecode first. */
prevbc = bc;
bc = STAILQ_NEXT(bc, link);
/* Iterate through the remainder, if any. */
while (bc) {
if (bc->callback->special == YASM_BC_SPECIAL_OFFSET) {
/* Recalculate/adjust len of offset-based bytecodes here */
long neg_thres = 0;
long pos_thres = (long)yasm_bc_next_offset(bc);
int retval = yasm_bc_expand(bc, 1, 0,
(long)yasm_bc_next_offset(prevbc),
&neg_thres, &pos_thres);
yasm_errwarn_propagate(errwarns, bc->line);
if (retval < 0)
saw_error = 1;
}
bc->offset = offset;
offset += bc->len*bc->mult_int;
prevbc = bc;
bc = STAILQ_NEXT(bc, link);
}
}
return saw_error;
}
static void
span_destroy(/*@only@*/ yasm_span *span)
{
unsigned int i;
yasm_value_delete(&span->depval);
if (span->rel_term)
yasm_xfree(span->rel_term);
if (span->terms)
yasm_xfree(span->terms);
if (span->items) {
for (i=0; i<span->num_terms; i++)
yasm_intnum_destroy(span->items[i].data.intn);
yasm_xfree(span->items);
}
if (span->backtrace)
yasm_xfree(span->backtrace);
yasm_xfree(span);
}
static void
optimize_cleanup(optimize_data *optd)
{
yasm_span *s1, *s2;
yasm_offset_setter *os1, *os2;
IT_destroy(optd->itree);
s1 = TAILQ_FIRST(&optd->spans);
while (s1) {
s2 = TAILQ_NEXT(s1, link);
span_destroy(s1);
s1 = s2;
}
os1 = STAILQ_FIRST(&optd->offset_setters);
while (os1) {
os2 = STAILQ_NEXT(os1, link);
yasm_xfree(os1);
os1 = os2;
}
}
static void
optimize_itree_add(IntervalTree *itree, yasm_span *span, yasm_span_term *term)
{
long precbc_index, precbc2_index;
unsigned long low, high;
/* Update term length */
if (term->precbc)
precbc_index = term->precbc->bc_index;
else
precbc_index = span->bc->bc_index-1;
if (term->precbc2)
precbc2_index = term->precbc2->bc_index;
else
precbc2_index = span->bc->bc_index-1;
if (precbc_index < precbc2_index) {
low = precbc_index+1;
high = precbc2_index;
} else if (precbc_index > precbc2_index) {
low = precbc2_index+1;
high = precbc_index;
} else
return; /* difference is same bc - always 0! */
IT_insert(itree, (long)low, (long)high, term);
}
static void
check_cycle(IntervalTreeNode *node, void *d)
{
optimize_data *optd = d;
yasm_span_term *term = node->data;
yasm_span *depspan = term->span;
int i;
int depspan_bt_alloc;
/* Only check for cycles in id=0 spans */
if (depspan->id > 0)
return;
/* Check for a circular reference by looking to see if this dependent
* span is in our backtrace.
*/
if (optd->span->backtrace) {
for (i=0; i<optd->span->backtrace_size; i++) {
if (optd->span->backtrace[i] == depspan)
yasm_error_set(YASM_ERROR_VALUE,
N_("circular reference detected"));
}
}
/* Add our complete backtrace and ourselves to backtrace of dependent
* span.
*/
if (!depspan->backtrace) {
depspan->backtrace = yasm_xmalloc((optd->span->backtrace_size+1)*
sizeof(yasm_span *));
if (optd->span->backtrace_size > 0)
memcpy(depspan->backtrace, optd->span->backtrace,
optd->span->backtrace_size*sizeof(yasm_span *));
depspan->backtrace[optd->span->backtrace_size] = optd->span;
depspan->backtrace_size = optd->span->backtrace_size+1;
return;
}
/* Add our complete backtrace, checking for duplicates */
depspan_bt_alloc = depspan->backtrace_size;
for (i=0; i<optd->span->backtrace_size; i++) {
int present = 0;
int j;
for (j=0; j<depspan->backtrace_size; j++) {
if (optd->span->backtrace[i] == optd->span->backtrace[j]) {
present = 1;
break;
}
}
if (present)
continue;
/* Not already in array; add it. */
if (depspan->backtrace_size >= depspan_bt_alloc)
{
depspan_bt_alloc *= 2;
depspan->backtrace =
yasm_xrealloc(depspan->backtrace,
depspan_bt_alloc*sizeof(yasm_span *));
}
depspan->backtrace[depspan->backtrace_size] = optd->span->backtrace[i];
depspan->backtrace_size++;
}
/* Add ourselves. */
if (depspan->backtrace_size >= depspan_bt_alloc)
{
depspan_bt_alloc++;
depspan->backtrace =
yasm_xrealloc(depspan->backtrace,
depspan_bt_alloc*sizeof(yasm_span *));
}
depspan->backtrace[depspan->backtrace_size] = optd->span;
depspan->backtrace_size++;
}
static void
optimize_term_expand(IntervalTreeNode *node, void *d)
{
optimize_data *optd = d;
yasm_span_term *term = node->data;
yasm_span *span = term->span;
long len_diff = optd->len_diff;
long precbc_index, precbc2_index;
/* Don't expand inactive spans */
if (!span->active)
return;
/* Update term length */
if (term->precbc)
precbc_index = term->precbc->bc_index;
else
precbc_index = span->bc->bc_index-1;
if (term->precbc2)
precbc2_index = term->precbc2->bc_index;
else
precbc2_index = span->bc->bc_index-1;
if (precbc_index < precbc2_index)
term->new_val += len_diff;
else
term->new_val -= len_diff;
/* If already on Q, don't re-add */
if (span->active == 2)
return;
/* Update term and check against thresholds */
if (!recalc_normal_span(span))
return; /* didn't exceed thresholds, we're done */
/* Exceeded thresholds, need to add to Q for expansion */
if (span->id <= 0)
STAILQ_INSERT_TAIL(&optd->QA, span, linkq);
else
STAILQ_INSERT_TAIL(&optd->QB, span, linkq);
span->active = 2; /* Mark as being in Q */
}
void
yasm_object_optimize(yasm_object *object, yasm_errwarns *errwarns)
{
yasm_section *sect;
unsigned long bc_index = 0;
int saw_error = 0;
optimize_data optd;
yasm_span *span, *span_temp;
yasm_offset_setter *os;
int retval;
unsigned int i;
TAILQ_INIT(&optd.spans);
STAILQ_INIT(&optd.offset_setters);
optd.itree = IT_create();
/* Create an placeholder offset setter for spans to point to; this will
* get updated if/when we actually run into one.
*/
os = yasm_xmalloc(sizeof(yasm_offset_setter));
os->bc = NULL;
os->cur_val = 0;
os->new_val = 0;
os->thres = 0;
STAILQ_INSERT_TAIL(&optd.offset_setters, os, link);
optd.os = os;
/* Step 1a */
STAILQ_FOREACH(sect, &object->sections, link) {
unsigned long offset = 0;
yasm_bytecode *bc = STAILQ_FIRST(§->bcs);
bc->bc_index = bc_index++;
/* Skip our locally created empty bytecode first. */
bc = STAILQ_NEXT(bc, link);
/* Iterate through the remainder, if any. */
while (bc) {
bc->bc_index = bc_index++;
bc->offset = offset;
retval = yasm_bc_calc_len(bc, optimize_add_span, &optd);
yasm_errwarn_propagate(errwarns, bc->line);
if (retval)
saw_error = 1;
else {
if (bc->callback->special == YASM_BC_SPECIAL_OFFSET) {
/* Remember it as offset setter */
os->bc = bc;
os->thres = yasm_bc_next_offset(bc);
/* Create new placeholder */
os = yasm_xmalloc(sizeof(yasm_offset_setter));
os->bc = NULL;
os->cur_val = 0;
os->new_val = 0;
os->thres = 0;
STAILQ_INSERT_TAIL(&optd.offset_setters, os, link);
optd.os = os;
if (bc->multiple) {
yasm_error_set(YASM_ERROR_VALUE,
N_("cannot combine multiples and setting assembly position"));
yasm_errwarn_propagate(errwarns, bc->line);
saw_error = 1;
}
}
offset += bc->len*bc->mult_int;
}
bc = STAILQ_NEXT(bc, link);
}
}
if (saw_error) {
optimize_cleanup(&optd);
return;
}
/* Step 1b */
TAILQ_FOREACH_SAFE(span, &optd.spans, link, span_temp) {
span_create_terms(span);
if (yasm_error_occurred()) {
yasm_errwarn_propagate(errwarns, span->bc->line);
saw_error = 1;
} else if (recalc_normal_span(span)) {
retval = yasm_bc_expand(span->bc, span->id, span->cur_val,
span->new_val, &span->neg_thres,
&span->pos_thres);
yasm_errwarn_propagate(errwarns, span->bc->line);
if (retval < 0)
saw_error = 1;
else if (retval > 0) {
if (!span->active) {
yasm_error_set(YASM_ERROR_VALUE,
N_("secondary expansion of an external/complex value"));
yasm_errwarn_propagate(errwarns, span->bc->line);
saw_error = 1;
}
} else {
TAILQ_REMOVE(&optd.spans, span, link);
span_destroy(span);
continue;
}
}
span->cur_val = span->new_val;
}
if (saw_error) {
optimize_cleanup(&optd);
return;
}
/* Step 1c */
if (update_all_bc_offsets(object, errwarns)) {
optimize_cleanup(&optd);
return;
}
/* Step 1d */
STAILQ_INIT(&optd.QB);
TAILQ_FOREACH(span, &optd.spans, link) {
yasm_intnum *intn;
/* Update span terms based on new bc offsets */
for (i=0; i<span->num_terms; i++) {
intn = yasm_calc_bc_dist(span->terms[i].precbc,
span->terms[i].precbc2);
if (!intn)
yasm_internal_error(N_("could not calculate bc distance"));
span->terms[i].cur_val = span->terms[i].new_val;
span->terms[i].new_val = yasm_intnum_get_int(intn);
yasm_intnum_destroy(intn);
}
if (span->rel_term) {
span->rel_term->cur_val = span->rel_term->new_val;
if (span->rel_term->precbc2)
span->rel_term->new_val =
yasm_bc_next_offset(span->rel_term->precbc2) -
span->bc->offset;
else
span->rel_term->new_val = span->bc->offset -
yasm_bc_next_offset(span->rel_term->precbc);
}
if (recalc_normal_span(span)) {
/* Exceeded threshold, add span to QB */
STAILQ_INSERT_TAIL(&optd.QB, span, linkq);
span->active = 2;
}
}
/* Do we need step 2? If not, go ahead and exit. */
if (STAILQ_EMPTY(&optd.QB)) {
optimize_cleanup(&optd);
return;
}
/* Update offset-setters values */
STAILQ_FOREACH(os, &optd.offset_setters, link) {
if (!os->bc)
continue;
os->thres = yasm_bc_next_offset(os->bc);
os->new_val = os->bc->offset;
os->cur_val = os->new_val;
}
/* Build up interval tree */
TAILQ_FOREACH(span, &optd.spans, link) {
for (i=0; i<span->num_terms; i++)
optimize_itree_add(optd.itree, span, &span->terms[i]);
if (span->rel_term)
optimize_itree_add(optd.itree, span, span->rel_term);
}
/* Look for cycles in times expansion (span.id==0) */
TAILQ_FOREACH(span, &optd.spans, link) {
if (span->id > 0)
continue;
optd.span = span;
IT_enumerate(optd.itree, (long)span->bc->bc_index,
(long)span->bc->bc_index, &optd, check_cycle);
if (yasm_error_occurred()) {
yasm_errwarn_propagate(errwarns, span->bc->line);
saw_error = 1;
}
}
if (saw_error) {
optimize_cleanup(&optd);
return;
}
/* Step 2 */
STAILQ_INIT(&optd.QA);
while (!STAILQ_EMPTY(&optd.QA) || !(STAILQ_EMPTY(&optd.QB))) {
unsigned long orig_len;
long offset_diff;
/* QA is for TIMES, update those first, then update non-TIMES.
* This is so that TIMES can absorb increases before we look at
* expanding non-TIMES BCs.
*/
if (!STAILQ_EMPTY(&optd.QA)) {
span = STAILQ_FIRST(&optd.QA);
STAILQ_REMOVE_HEAD(&optd.QA, linkq);
} else {
span = STAILQ_FIRST(&optd.QB);
STAILQ_REMOVE_HEAD(&optd.QB, linkq);
}
if (!span->active)
continue;
span->active = 1; /* no longer in Q */
/* Make sure we ended up ultimately exceeding thresholds; due to
* offset BCs we may have been placed on Q and then reduced in size
* again.
*/
if (!recalc_normal_span(span))
continue;
orig_len = span->bc->len * span->bc->mult_int;
retval = yasm_bc_expand(span->bc, span->id, span->cur_val,
span->new_val, &span->neg_thres,
&span->pos_thres);
yasm_errwarn_propagate(errwarns, span->bc->line);
if (retval < 0) {
/* error */
saw_error = 1;
continue;
} else if (retval > 0) {
/* another threshold, keep active */
for (i=0; i<span->num_terms; i++)
span->terms[i].cur_val = span->terms[i].new_val;
if (span->rel_term)
span->rel_term->cur_val = span->rel_term->new_val;
span->cur_val = span->new_val;
} else
span->active = 0; /* we're done with this span */
optd.len_diff = span->bc->len * span->bc->mult_int - orig_len;
if (optd.len_diff == 0)
continue; /* didn't increase in size */
/* Iterate over all spans dependent across the bc just expanded */
IT_enumerate(optd.itree, (long)span->bc->bc_index,
(long)span->bc->bc_index, &optd, optimize_term_expand);
/* Iterate over offset-setters that follow the bc just expanded.
* Stop iteration if:
* - no more offset-setters in this section
* - offset-setter didn't move its following offset
*/
os = span->os;
offset_diff = optd.len_diff;
while (os->bc && os->bc->section == span->bc->section
&& offset_diff != 0) {
unsigned long old_next_offset = os->cur_val + os->bc->len;
long neg_thres_temp;
if (offset_diff < 0 && (unsigned long)(-offset_diff) > os->new_val)
yasm_internal_error(N_("org/align went to negative offset"));
os->new_val += offset_diff;
orig_len = os->bc->len;
retval = yasm_bc_expand(os->bc, 1, (long)os->cur_val,
(long)os->new_val, &neg_thres_temp,
(long *)&os->thres);
yasm_errwarn_propagate(errwarns, os->bc->line);
offset_diff = os->new_val + os->bc->len - old_next_offset;
optd.len_diff = os->bc->len - orig_len;
if (optd.len_diff != 0)
IT_enumerate(optd.itree, (long)os->bc->bc_index,
(long)os->bc->bc_index, &optd, optimize_term_expand);
os->cur_val = os->new_val;
os = STAILQ_NEXT(os, link);
}
}
if (saw_error) {
optimize_cleanup(&optd);
return;
}
/* Step 3 */
update_all_bc_offsets(object, errwarns);
optimize_cleanup(&optd);
}